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bf95c10a 1## Copyright (C) 1996-2022 The Squid Software Foundation and contributors
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2##
3## Squid software is distributed under GPLv2+ license and includes
4## contributions from numerous individuals and organizations.
5## Please see the COPYING and CONTRIBUTORS files for details.
6##
9cef6668 7
0f74202c 8COMMENT_START
ad12fb4b 9 WELCOME TO @SQUID@
cccac0a2 10 ----------------------------
9603207d 11
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12 This is the documentation for the Squid configuration file.
13 This documentation can also be found online at:
14 http://www.squid-cache.org/Doc/config/
9603207d 15
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16 You may wish to look at the Squid home page and wiki for the
17 FAQ and other documentation:
18 http://www.squid-cache.org/
19 http://wiki.squid-cache.org/SquidFaq
20 http://wiki.squid-cache.org/ConfigExamples
9603207d 21
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22 This documentation shows what the defaults for various directives
23 happen to be. If you don't need to change the default, you should
24 leave the line out of your squid.conf in most cases.
9603207d 25
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26 In some cases "none" refers to no default setting at all,
27 while in other cases it refers to the value of the option
28 - the comments for that keyword indicate if this is the case.
debd9a31 29
cccac0a2 30COMMENT_END
3a278cb8 31
592a09dc 32COMMENT_START
33 Configuration options can be included using the "include" directive.
5945964d 34 Include takes a list of files to include. Quoting and wildcards are
592a09dc 35 supported.
36
37 For example,
38
39 include /path/to/included/file/squid.acl.config
40
41 Includes can be nested up to a hard-coded depth of 16 levels.
42 This arbitrary restriction is to prevent recursive include references
43 from causing Squid entering an infinite loop whilst trying to load
44 configuration files.
d4a3e179 45
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46 Values with byte units
47
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48 Squid accepts size units on some size related directives. All
49 such directives are documented with a default value displaying
50 a unit.
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51
52 Units accepted by Squid are:
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53 bytes - byte
54 KB - Kilobyte (1024 bytes)
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55 MB - Megabyte
56 GB - Gigabyte
d4a3e179 57
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58 Values with time units
59
60 Time-related directives marked with either "time-units" or
61 "time-units-small" accept a time unit. The supported time units are:
62
63 nanosecond (time-units-small only)
64 microsecond (time-units-small only)
65 millisecond
66 second
67 minute
68 hour
69 day
70 week
71 fortnight
72 month - 30 days
73 year - 31557790080 milliseconds (just over 365 days)
74 decade
75
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76 Values with spaces, quotes, and other special characters
77
78 Squid supports directive parameters with spaces, quotes, and other
79 special characters. Surround such parameters with "double quotes". Use
80 the configuration_includes_quoted_values directive to enable or
81 disable that support.
82
83 Squid supports reading configuration option parameters from external
84 files using the syntax:
85 parameters("/path/filename")
86 For example:
70d0ef18 87 acl allowlist dstdomain parameters("/etc/squid/allowlist.txt")
2eceb328 88
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89 Conditional configuration
90
91 If-statements can be used to make configuration directives
92 depend on conditions:
93
94 if <CONDITION>
95 ... regular configuration directives ...
96 [else
97 ... regular configuration directives ...]
98 endif
99
100 The else part is optional. The keywords "if", "else", and "endif"
101 must be typed on their own lines, as if they were regular
102 configuration directives.
103
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104 NOTE: An else-if condition is not supported.
105
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106 These individual conditions types are supported:
107
108 true
109 Always evaluates to true.
110 false
111 Always evaluates to false.
112 <integer> = <integer>
113 Equality comparison of two integer numbers.
114
115
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116 SMP-Related Macros
117
118 The following SMP-related preprocessor macros can be used.
119
120 ${process_name} expands to the current Squid process "name"
121 (e.g., squid1, squid2, or cache1).
122
123 ${process_number} expands to the current Squid process
124 identifier, which is an integer number (e.g., 1, 2, 3) unique
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125 across all Squid processes of the current service instance.
126
127 ${service_name} expands into the current Squid service instance
128 name identifier which is provided by -n on the command line.
129
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130 Logformat Macros
131
132 Logformat macros can be used in many places outside of the logformat
133 directive. In theory, all of the logformat codes can be used as %macros,
134 where they are supported. In practice, a %macro expands as a dash (-) when
135 the transaction does not yet have enough information and a value is needed.
136
137 There is no definitive list of what tokens are available at the various
138 stages of the transaction.
139
140 And some information may already be available to Squid but not yet
141 committed where the macro expansion code can access it (report
142 such instances!). The macro will be expanded into a single dash
143 ('-') in such cases. Not all macros have been tested.
144
592a09dc 145COMMENT_END
146
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147# options still not yet ported from 2.7 to 3.x
148NAME: broken_vary_encoding
149TYPE: obsolete
150DOC_START
151 This option is not yet supported by Squid-3.
152DOC_END
153
154NAME: cache_vary
155TYPE: obsolete
156DOC_START
157 This option is not yet supported by Squid-3.
158DOC_END
159
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160NAME: error_map
161TYPE: obsolete
162DOC_START
163 This option is not yet supported by Squid-3.
164DOC_END
165
166NAME: external_refresh_check
167TYPE: obsolete
168DOC_START
169 This option is not yet supported by Squid-3.
170DOC_END
171
96598f93 172NAME: location_rewrite_program location_rewrite_access location_rewrite_children location_rewrite_concurrency
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173TYPE: obsolete
174DOC_START
175 This option is not yet supported by Squid-3.
176DOC_END
177
96598f93 178NAME: refresh_stale_hit
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179TYPE: obsolete
180DOC_START
181 This option is not yet supported by Squid-3.
182DOC_END
183
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184# Options removed in 6.x
185NAME: request_entities
186TYPE: obsolete
187DOC_START
188 Remove this line. Squid now accepts HTTP/1.1 requests with bodies.
189 To simplify UI and code, Squid rejects certain HTTP/1.0 requests with bodies.
190DOC_END
191
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192# Options removed in 5.x
193NAME: dns_v4_first
194TYPE: obsolete
195DOC_START
196 Remove this line. Squid no longer supports preferential treatment of DNS A records.
197DOC_END
198
6eb545bc 199# Options removed in 4.x
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200NAME: cache_peer_domain cache_host_domain
201TYPE: obsolete
202DOC_START
203 Replace with dstdomain ACLs and cache_peer_access.
204DOC_END
205
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206NAME: ie_refresh
207TYPE: obsolete
208DOC_START
209 Remove this line. The behaviour enabled by this is no longer needed.
210DOC_END
211
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212NAME: sslproxy_cafile
213TYPE: obsolete
214DOC_START
215 Remove this line. Use tls_outgoing_options cafile= instead.
216DOC_END
217
218NAME: sslproxy_capath
219TYPE: obsolete
220DOC_START
221 Remove this line. Use tls_outgoing_options capath= instead.
222DOC_END
223
224NAME: sslproxy_cipher
225TYPE: obsolete
226DOC_START
227 Remove this line. Use tls_outgoing_options cipher= instead.
228DOC_END
229
230NAME: sslproxy_client_certificate
231TYPE: obsolete
232DOC_START
233 Remove this line. Use tls_outgoing_options cert= instead.
234DOC_END
235
236NAME: sslproxy_client_key
237TYPE: obsolete
238DOC_START
239 Remove this line. Use tls_outgoing_options key= instead.
240DOC_END
241
242NAME: sslproxy_flags
243TYPE: obsolete
244DOC_START
245 Remove this line. Use tls_outgoing_options flags= instead.
246DOC_END
247
248NAME: sslproxy_options
249TYPE: obsolete
250DOC_START
251 Remove this line. Use tls_outgoing_options options= instead.
252DOC_END
253
254NAME: sslproxy_version
255TYPE: obsolete
256DOC_START
1cc44095 257 Remove this line. Use tls_outgoing_options options= instead.
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258DOC_END
259
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260# Options removed in 3.5
261NAME: hierarchy_stoplist
262TYPE: obsolete
263DOC_START
264 Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
265DOC_END
266
a8f70484 267# Options removed in 3.4
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268NAME: log_access
269TYPE: obsolete
270DOC_START
271 Remove this line. Use acls with access_log directives to control access logging
272DOC_END
273
274NAME: log_icap
275TYPE: obsolete
276DOC_START
277 Remove this line. Use acls with icap_log directives to control icap logging
278DOC_END
279
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280# Options Removed in 3.3
281NAME: ignore_ims_on_miss
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282TYPE: obsolete
283DOC_START
2d4eefd9 284 Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
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285DOC_END
286
76f44481 287# Options Removed in 3.2
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288NAME: balance_on_multiple_ip
289TYPE: obsolete
290DOC_START
291 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, this multiple-IP algorithm is not longer relevant.
292DOC_END
293
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294NAME: chunked_request_body_max_size
295TYPE: obsolete
296DOC_START
297 Remove this line. Squid is now HTTP/1.1 compliant.
298DOC_END
299
74d81220 300NAME: dns_v4_fallback
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301TYPE: obsolete
302DOC_START
74d81220 303 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
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304DOC_END
305
74d81220 306NAME: emulate_httpd_log
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307TYPE: obsolete
308DOC_START
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309 Replace this with an access_log directive using the format 'common' or 'combined'.
310DOC_END
311
312NAME: forward_log
313TYPE: obsolete
314DOC_START
315 Use a regular access.log with ACL limiting it to MISS events.
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316DOC_END
317
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318NAME: ftp_list_width
319TYPE: obsolete
320DOC_START
321 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
322DOC_END
323
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324NAME: ignore_expect_100
325TYPE: obsolete
326DOC_START
327 Remove this line. The HTTP/1.1 feature is now fully supported by default.
328DOC_END
329
330NAME: log_fqdn
331TYPE: obsolete
332DOC_START
333 Remove this option from your config. To log FQDN use %>A in the log format.
334DOC_END
335
336NAME: log_ip_on_direct
337TYPE: obsolete
338DOC_START
339 Remove this option from your config. To log server or peer names use %<A in the log format.
340DOC_END
341
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342NAME: maximum_single_addr_tries
343TYPE: obsolete
344DOC_START
345 Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
346DOC_END
347
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348NAME: referer_log referrer_log
349TYPE: obsolete
350DOC_START
351 Replace this with an access_log directive using the format 'referrer'.
352DOC_END
353
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354NAME: update_headers
355TYPE: obsolete
356DOC_START
357 Remove this line. The feature is supported by default in storage types where update is implemented.
358DOC_END
359
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360NAME: url_rewrite_concurrency
361TYPE: obsolete
362DOC_START
363 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
364DOC_END
365
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366NAME: useragent_log
367TYPE: obsolete
368DOC_START
369 Replace this with an access_log directive using the format 'useragent'.
370DOC_END
371
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372# Options Removed in 3.1
373NAME: dns_testnames
374TYPE: obsolete
375DOC_START
376 Remove this line. DNS is no longer tested on startup.
377DOC_END
378
379NAME: extension_methods
380TYPE: obsolete
381DOC_START
382 Remove this line. All valid methods for HTTP are accepted by default.
383DOC_END
384
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385# 2.7 Options Removed/Replaced in 3.2
386NAME: zero_buffers
387TYPE: obsolete
388DOC_NONE
389
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390# 2.7 Options Removed/Replaced in 3.1
391NAME: incoming_rate
392TYPE: obsolete
393DOC_NONE
394
395NAME: server_http11
396TYPE: obsolete
397DOC_START
398 Remove this line. HTTP/1.1 is supported by default.
399DOC_END
400
401NAME: upgrade_http0.9
402TYPE: obsolete
403DOC_START
404 Remove this line. ICY/1.0 streaming protocol is supported by default.
405DOC_END
406
407NAME: zph_local zph_mode zph_option zph_parent zph_sibling
408TYPE: obsolete
409DOC_START
410 Alter these entries. Use the qos_flows directive instead.
411DOC_END
412
413# Options Removed in 3.0
414NAME: header_access
415TYPE: obsolete
416DOC_START
417 Since squid-3.0 replace with request_header_access or reply_header_access
418 depending on whether you wish to match client requests or server replies.
419DOC_END
420
421NAME: httpd_accel_no_pmtu_disc
422TYPE: obsolete
423DOC_START
424 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
425DOC_END
426
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427NAME: wais_relay_host
428TYPE: obsolete
429DOC_START
430 Replace this line with 'cache_peer' configuration.
431DOC_END
432
433NAME: wais_relay_port
434TYPE: obsolete
435DOC_START
436 Replace this line with 'cache_peer' configuration.
437DOC_END
438
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439COMMENT_START
440 OPTIONS FOR SMP
441 -----------------------------------------------------------------------------
442COMMENT_END
443
444NAME: workers
445TYPE: int
446LOC: Config.workers
447DEFAULT: 1
448DEFAULT_DOC: SMP support disabled.
449DOC_START
450 Number of main Squid processes or "workers" to fork and maintain.
451 0: "no daemon" mode, like running "squid -N ..."
452 1: "no SMP" mode, start one main Squid process daemon (default)
453 N: start N main Squid process daemons (i.e., SMP mode)
454
455 In SMP mode, each worker does nearly all what a single Squid daemon
456 does (e.g., listen on http_port and forward HTTP requests).
457DOC_END
458
459NAME: cpu_affinity_map
460TYPE: CpuAffinityMap
461LOC: Config.cpuAffinityMap
462DEFAULT: none
463DEFAULT_DOC: Let operating system decide.
464DOC_START
465 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
466
467 Sets 1:1 mapping between Squid processes and CPU cores. For example,
468
469 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
470
471 affects processes 1 through 4 only and places them on the first
472 four even cores, starting with core #1.
473
474 CPU cores are numbered starting from 1. Requires support for
475 sched_getaffinity(2) and sched_setaffinity(2) system calls.
476
477 Multiple cpu_affinity_map options are merged.
478
479 See also: workers
480DOC_END
481
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482NAME: shared_memory_locking
483TYPE: YesNoNone
484COMMENT: on|off
485LOC: Config.shmLocking
486DEFAULT: off
487DOC_START
488 Whether to ensure that all required shared memory is available by
489 "locking" that shared memory into RAM when Squid starts. The
490 alternative is faster startup time followed by slightly slower
491 performance and, if not enough RAM is actually available during
492 runtime, mysterious crashes.
493
494 SMP Squid uses many shared memory segments. These segments are
495 brought into Squid memory space using an mmap(2) system call. During
496 Squid startup, the mmap() call often succeeds regardless of whether
497 the system has enough RAM. In general, Squid cannot tell whether the
498 kernel applies this "optimistic" memory allocation policy (but
499 popular modern kernels usually use it).
500
501 Later, if Squid attempts to actually access the mapped memory
502 regions beyond what the kernel is willing to allocate, the
503 "optimistic" kernel simply kills Squid kid with a SIGBUS signal.
504 Some of the memory limits enforced by the kernel are currently
505 poorly understood: We do not know how to detect and check them. This
9603207d 506 option ensures that the mapped memory will be available.
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507
508 This option may have a positive performance side-effect: Locking
509 memory at start avoids runtime paging I/O. Paging slows Squid down.
510
511 Locking memory may require a large enough RLIMIT_MEMLOCK OS limit,
512 CAP_IPC_LOCK capability, or equivalent.
513DOC_END
514
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515NAME: hopeless_kid_revival_delay
516COMMENT: time-units
517TYPE: time_t
518LOC: Config.hopelessKidRevivalDelay
519DEFAULT: 1 hour
520DOC_START
521 Normally, when a kid process dies, Squid immediately restarts the
522 kid. A kid experiencing frequent deaths is marked as "hopeless" for
523 the duration specified by this directive. Hopeless kids are not
524 automatically restarted.
525
526 Currently, zero values are not supported because they result in
527 misconfigured SMP Squid instances running forever, endlessly
528 restarting each dying kid. To effectively disable hopeless kids
529 revival, set the delay to a huge value (e.g., 1 year).
530
531 Reconfiguration also clears all hopeless kids designations, allowing
532 for manual revival of hopeless kids.
533DOC_END
534
5473c134 535COMMENT_START
41bd17a4 536 OPTIONS FOR AUTHENTICATION
5473c134 537 -----------------------------------------------------------------------------
538COMMENT_END
539
41bd17a4 540NAME: auth_param
541TYPE: authparam
2f1431ea 542IFDEF: USE_AUTH
5c112575 543LOC: Auth::TheConfig.schemes
cccac0a2 544DEFAULT: none
545DOC_START
41bd17a4 546 This is used to define parameters for the various authentication
547 schemes supported by Squid.
cccac0a2 548
66c583dc 549 format: auth_param scheme parameter [setting]
cccac0a2 550
41bd17a4 551 The order in which authentication schemes are presented to the client is
552 dependent on the order the scheme first appears in config file. IE
553 has a bug (it's not RFC 2617 compliant) in that it will use the basic
554 scheme if basic is the first entry presented, even if more secure
555 schemes are presented. For now use the order in the recommended
556 settings section below. If other browsers have difficulties (don't
557 recognize the schemes offered even if you are using basic) either
558 put basic first, or disable the other schemes (by commenting out their
559 program entry).
cccac0a2 560
41bd17a4 561 Once an authentication scheme is fully configured, it can only be
562 shutdown by shutting squid down and restarting. Changes can be made on
563 the fly and activated with a reconfigure. I.E. You can change to a
564 different helper, but not unconfigure the helper completely.
cccac0a2 565
41bd17a4 566 Please note that while this directive defines how Squid processes
567 authentication it does not automatically activate authentication.
568 To use authentication you must in addition make use of ACLs based
569 on login name in http_access (proxy_auth, proxy_auth_regex or
570 external with %LOGIN used in the format tag). The browser will be
571 challenged for authentication on the first such acl encountered
572 in http_access processing and will also be re-challenged for new
573 login credentials if the request is being denied by a proxy_auth
574 type acl.
cccac0a2 575
41bd17a4 576 WARNING: authentication can't be used in a transparently intercepting
577 proxy as the client then thinks it is talking to an origin server and
578 not the proxy. This is a limitation of bending the TCP/IP protocol to
579 transparently intercepting port 80, not a limitation in Squid.
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580 Ports flagged 'transparent', 'intercept', or 'tproxy' have
581 authentication disabled.
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583 === Parameters common to all schemes. ===
584
585 "program" cmdline
66c583dc 586 Specifies the command for the external authenticator.
d4806c91 587
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588 By default, each authentication scheme is not used unless a
589 program is specified.
cccac0a2 590
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591 See http://wiki.squid-cache.org/Features/AddonHelpers for
592 more details on helper operations and creating your own.
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594 "key_extras" format
595 Specifies a string to be append to request line format for
596 the authentication helper. "Quoted" format values may contain
597 spaces and logformat %macros. In theory, any logformat %macro
598 can be used. In practice, a %macro expands as a dash (-) if
599 the helper request is sent before the required macro
600 information is available to Squid.
601
602 By default, Squid uses request formats provided in
603 scheme-specific examples below (search for %credentials).
604
605 The expanded key_extras value is added to the Squid credentials
606 cache and, hence, will affect authentication. It can be used to
2f8abb64 607 authenticate different users with identical user names (e.g.,
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608 when user authentication depends on http_port).
609
610 Avoid adding frequently changing information to key_extras. For
611 example, if you add user source IP, and it changes frequently
612 in your environment, then max_user_ip ACL is going to treat
613 every user+IP combination as a unique "user", breaking the ACL
614 and wasting a lot of memory on those user records. It will also
615 force users to authenticate from scratch whenever their IP
616 changes.
617
618 "realm" string
619 Specifies the protection scope (aka realm name) which is to be
620 reported to the client for the authentication scheme. It is
621 commonly part of the text the user will see when prompted for
622 their username and password.
623
624 For Basic the default is "Squid proxy-caching web server".
625 For Digest there is no default, this parameter is mandatory.
626 For NTLM and Negotiate this parameter is ignored.
5269ec0e 627
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628 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
629 [queue-size=N] [on-persistent-overload=action]
a56fcf0b 630 [reservation-timeout=seconds]
5269ec0e 631
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632 The maximum number of authenticator processes to spawn. If
633 you start too few Squid will have to wait for them to process
634 a backlog of credential verifications, slowing it down. When
635 password verifications are done via a (slow) network you are
636 likely to need lots of authenticator processes.
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638 The startup= and idle= options permit some skew in the exact
639 amount run. A minimum of startup=N will begin during startup
640 and reconfigure. Squid will start more in groups of up to
641 idle=N in an attempt to meet traffic needs and to keep idle=N
642 free above those traffic needs up to the maximum.
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644 The concurrency= option sets the number of concurrent requests
645 the helper can process. The default of 0 is used for helpers
646 who only supports one request at a time. Setting this to a
647 number greater than 0 changes the protocol used to include a
648 channel ID field first on the request/response line, allowing
649 multiple requests to be sent to the same helper in parallel
650 without waiting for the response.
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652 Concurrency must not be set unless it's known the helper
653 supports the input format with channel-ID fields.
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655 The queue-size option sets the maximum number of queued
656 requests. A request is queued when no existing child can
657 accept it due to concurrency limit and no new child can be
658 started due to numberofchildren limit. The default maximum is
659 2*numberofchildren. Squid is allowed to temporarily exceed the
660 configured maximum, marking the affected helper as
661 "overloaded". If the helper overload lasts more than 3
662 minutes, the action prescribed by the on-persistent-overload
663 option applies.
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664
665 The on-persistent-overload=action option specifies Squid
666 reaction to a new helper request arriving when the helper
667 has been overloaded for more that 3 minutes already. The number
668 of queued requests determines whether the helper is overloaded
669 (see the queue-size option).
670
671 Two actions are supported:
672
673 die Squid worker quits. This is the default behavior.
674
675 ERR Squid treats the helper request as if it was
676 immediately submitted, and the helper immediately
677 replied with an ERR response. This action has no effect
678 on the already queued and in-progress helper requests.
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680 NOTE: NTLM and Negotiate schemes do not support concurrency
681 in the Squid code module even though some helpers can.
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683 The reservation-timeout=seconds option allows NTLM and Negotiate
684 helpers to forget about clients that abandon their in-progress
685 connection authentication without closing the connection. The
686 timeout is measured since the last helper response received by
687 Squid for the client. Fractional seconds are not supported.
688
689 After the timeout, the helper will be used for other clients if
690 there are no unreserved helpers available. In the latter case,
691 the old client attempt to resume authentication will not be
692 forwarded to the helper (and the client should open a new HTTP
693 connection and retry authentication from scratch).
694
695 By default, reservations do not expire and clients that keep
696 their connections open without completing authentication may
697 exhaust all NTLM and Negotiate helpers.
698
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699 "keep_alive" on|off
700 If you experience problems with PUT/POST requests when using
701 the NTLM or Negotiate schemes then you can try setting this
702 to off. This will cause Squid to forcibly close the connection
703 on the initial request where the browser asks which schemes
704 are supported by the proxy.
9e7dbc51 705
b2b09838 706 For Basic and Digest this parameter is ignored.
d2a89ac1 707
66c583dc 708 "utf8" on|off
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709 Useful for sending credentials to authentication backends that
710 expect UTF-8 encoding (e.g., LDAP).
711
712 When this option is enabled, Squid uses HTTP Accept-Language
713 request header to guess the received credentials encoding
714 (ISO-Latin-1, CP1251, or UTF-8) and then converts the first
715 two encodings into UTF-8.
716
717 When this option is disabled and by default, Squid sends
718 credentials in their original (i.e. received) encoding.
719
720 This parameter is only honored for Basic and Digest schemes.
721 For Basic, the entire username:password credentials are
722 checked and, if necessary, re-encoded. For Digest -- just the
723 username component. For NTLM and Negotiate schemes, this
724 parameter is ignored.
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725
726IF HAVE_AUTH_MODULE_BASIC
727 === Basic authentication parameters ===
728
41bd17a4 729 "credentialsttl" timetolive
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730 Specifies how long squid assumes an externally validated
731 username:password pair is valid for - in other words how
732 often the helper program is called for that user. Set this
733 low to force revalidation with short lived passwords.
cccac0a2 734
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735 NOTE: setting this high does not impact your susceptibility
736 to replay attacks unless you are using an one-time password
737 system (such as SecureID). If you are using such a system,
738 you will be vulnerable to replay attacks unless you also
739 use the max_user_ip ACL in an http_access rule.
cccac0a2 740
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741 "casesensitive" on|off
742 Specifies if usernames are case sensitive. Most user databases
743 are case insensitive allowing the same username to be spelled
744 using both lower and upper case letters, but some are case
745 sensitive. This makes a big difference for user_max_ip ACL
746 processing and similar.
cccac0a2 747
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748ENDIF
749IF HAVE_AUTH_MODULE_DIGEST
750 === Digest authentication parameters ===
cccac0a2 751
41bd17a4 752 "nonce_garbage_interval" timeinterval
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753 Specifies the interval that nonces that have been issued
754 to client_agent's are checked for validity.
cccac0a2 755
41bd17a4 756 "nonce_max_duration" timeinterval
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757 Specifies the maximum length of time a given nonce will be
758 valid for.
cccac0a2 759
41bd17a4 760 "nonce_max_count" number
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761 Specifies the maximum number of times a given nonce can be
762 used.
cccac0a2 763
41bd17a4 764 "nonce_strictness" on|off
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765 Determines if squid requires strict increment-by-1 behavior
766 for nonce counts, or just incrementing (off - for use when
767 user agents generate nonce counts that occasionally miss 1
768 (ie, 1,2,4,6)). Default off.
cccac0a2 769
41bd17a4 770 "check_nonce_count" on|off
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771 This directive if set to off can disable the nonce count check
772 completely to work around buggy digest qop implementations in
773 certain mainstream browser versions. Default on to check the
774 nonce count to protect from authentication replay attacks.
cccac0a2 775
41bd17a4 776 "post_workaround" on|off
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777 This is a workaround to certain buggy browsers who send an
778 incorrect request digest in POST requests when reusing the
779 same nonce as acquired earlier on a GET request.
cccac0a2 780
66c583dc 781ENDIF
527ee50d 782
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783 === Example Configuration ===
784
785 This configuration displays the recommended authentication scheme
786 order from most to least secure with recommended minimum configuration
787 settings for each scheme:
e0855596 788
41bd17a4 789#auth_param negotiate program <uncomment and complete this line to activate>
48d54e4d 790#auth_param negotiate children 20 startup=0 idle=1
e0855596 791#
66c583dc 792#auth_param digest program <uncomment and complete this line to activate>
48d54e4d 793#auth_param digest children 20 startup=0 idle=1
41bd17a4 794#auth_param digest realm Squid proxy-caching web server
795#auth_param digest nonce_garbage_interval 5 minutes
796#auth_param digest nonce_max_duration 30 minutes
797#auth_param digest nonce_max_count 50
e0855596 798#
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799#auth_param ntlm program <uncomment and complete this line to activate>
800#auth_param ntlm children 20 startup=0 idle=1
66c583dc 801#
41bd17a4 802#auth_param basic program <uncomment and complete this line>
6f4d3ed6 803#auth_param basic children 5 startup=5 idle=1
41bd17a4 804#auth_param basic credentialsttl 2 hours
41bd17a4 805DOC_END
cccac0a2 806
41bd17a4 807NAME: authenticate_cache_garbage_interval
5db226c8 808IFDEF: USE_AUTH
41bd17a4 809TYPE: time_t
810DEFAULT: 1 hour
00ef8d82 811LOC: Auth::TheConfig.garbageCollectInterval
41bd17a4 812DOC_START
813 The time period between garbage collection across the username cache.
4ded749e 814 This is a trade-off between memory utilization (long intervals - say
41bd17a4 815 2 days) and CPU (short intervals - say 1 minute). Only change if you
816 have good reason to.
817DOC_END
cccac0a2 818
41bd17a4 819NAME: authenticate_ttl
5db226c8 820IFDEF: USE_AUTH
41bd17a4 821TYPE: time_t
822DEFAULT: 1 hour
00ef8d82 823LOC: Auth::TheConfig.credentialsTtl
41bd17a4 824DOC_START
825 The time a user & their credentials stay in the logged in
826 user cache since their last request. When the garbage
827 interval passes, all user credentials that have passed their
828 TTL are removed from memory.
829DOC_END
cccac0a2 830
41bd17a4 831NAME: authenticate_ip_ttl
5db226c8 832IFDEF: USE_AUTH
41bd17a4 833TYPE: time_t
00ef8d82 834LOC: Auth::TheConfig.ipTtl
c35dd848 835DEFAULT: 1 second
41bd17a4 836DOC_START
837 If you use proxy authentication and the 'max_user_ip' ACL,
838 this directive controls how long Squid remembers the IP
839 addresses associated with each user. Use a small value
840 (e.g., 60 seconds) if your users might change addresses
4ded749e 841 quickly, as is the case with dialup. You might be safe
41bd17a4 842 using a larger value (e.g., 2 hours) in a corporate LAN
843 environment with relatively static address assignments.
844DOC_END
cccac0a2 845
3d1e3e43 846COMMENT_START
847 ACCESS CONTROLS
848 -----------------------------------------------------------------------------
849COMMENT_END
850
41bd17a4 851NAME: external_acl_type
852TYPE: externalAclHelper
853LOC: Config.externalAclHelperList
cccac0a2 854DEFAULT: none
cccac0a2 855DOC_START
41bd17a4 856 This option defines external acl classes using a helper program
857 to look up the status
cccac0a2 858
262eaf9a 859 external_acl_type name [options] FORMAT /path/to/helper [helper arguments]
cccac0a2 860
41bd17a4 861 Options:
cccac0a2 862
41bd17a4 863 ttl=n TTL in seconds for cached results (defaults to 3600
cd0fd8a9 864 for 1 hour)
4f8d0a65 865
41bd17a4 866 negative_ttl=n
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867 TTL for cached negative lookups (default same
868 as ttl)
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869
870 grace=n Percentage remaining of TTL where a refresh of a
871 cached entry should be initiated without needing to
872 wait for a new reply. (default is for no grace period)
873
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874 cache=n The maximum number of entries in the result cache. The
875 default limit is 262144 entries. Each cache entry usually
876 consumes at least 256 bytes. Squid currently does not remove
877 expired cache entries until the limit is reached, so a proxy
878 will sooner or later reach the limit. The expanded FORMAT
879 value is used as the cache key, so if the details in FORMAT
880 are highly variable, a larger cache may be needed to produce
881 reduction in helper load.
4f8d0a65 882
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883 children-max=n
884 Maximum number of acl helper processes spawned to service
2ccfb9a7 885 external acl lookups of this type. (default 5)
4f8d0a65 886
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887 children-startup=n
888 Minimum number of acl helper processes to spawn during
889 startup and reconfigure to service external acl lookups
890 of this type. (default 0)
4f8d0a65 891
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892 children-idle=n
893 Number of acl helper processes to keep ahead of traffic
894 loads. Squid will spawn this many at once whenever load
895 rises above the capabilities of existing processes.
896 Up to the value of children-max. (default 1)
4f8d0a65 897
41bd17a4 898 concurrency=n concurrency level per process. Only used with helpers
899 capable of processing more than one query at a time.
4f8d0a65 900
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901 queue-size=N The queue-size option sets the maximum number of
902 queued requests. A request is queued when no existing
903 helper can accept it due to concurrency limit and no
904 new helper can be started due to children-max limit.
905 If the queued requests exceed queue size, the acl is
906 ignored. The default value is set to 2*children-max.
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907
908 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers.
909
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910 ipv4 / ipv6 IP protocol used to communicate with this helper.
911 The default is to auto-detect IPv6 and use it when available.
cccac0a2 912
4f8d0a65 913
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914 FORMAT is a series of %macro codes. See logformat directive for a full list
915 of the accepted codes. Although note that at the time of any external ACL
916 being tested data may not be available and thus some %macro expand to '-'.
917
918 In addition to the logformat codes; when processing external ACLs these
919 additional macros are made available:
7b0ca1e8 920
ec2d5242 921 %ACL The name of the ACL being tested.
ec2d5242 922
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923 %DATA The ACL arguments specified in the referencing config
924 'acl ... external' line, separated by spaces (an
925 "argument string"). see acl external.
926
927 If there are no ACL arguments %DATA expands to '-'.
928
929 If you do not specify a DATA macro inside FORMAT,
930 Squid automatically appends %DATA to your FORMAT.
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931 Note that Squid-3.x may expand %DATA to whitespace
932 or nothing in this case.
cd0fd8a9 933
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CT
934 By default, Squid applies URL-encoding to each ACL
935 argument inside the argument string. If an explicit
936 encoding modifier is used (e.g., %#DATA), then Squid
937 encodes the whole argument string as a single token
938 (e.g., with %#DATA, spaces between arguments become
939 %20).
940
2f8abb64 941 If SSL is enabled, the following formatting codes become available:
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942
943 %USER_CERT SSL User certificate in PEM format
944 %USER_CERTCHAIN SSL User certificate chain in PEM format
945 %USER_CERT_xx SSL User certificate subject attribute xx
946 %USER_CA_CERT_xx SSL User certificate issuer attribute xx
947
948
949 NOTE: all other format codes accepted by older Squid versions
950 are deprecated.
0db8942f 951
cccac0a2 952
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953 General request syntax:
954
0638f4a2 955 [channel-ID] FORMAT-values
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956
957
958 FORMAT-values consists of transaction details expanded with
959 whitespace separation per the config file FORMAT specification
960 using the FORMAT macros listed above.
961
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962 Request values sent to the helper are URL escaped to protect
963 each value in requests against whitespaces.
964
965 If using protocol=2.5 then the request sent to the helper is not
966 URL escaped to protect against whitespace.
967
968 NOTE: protocol=3.0 is deprecated as no longer necessary.
969
970 When using the concurrency= option the protocol is changed by
971 introducing a query channel tag in front of the request/response.
972 The query channel tag is a number between 0 and concurrency-1.
973 This value must be echoed back unchanged to Squid as the first part
974 of the response relating to its request.
975
976
977 The helper receives lines expanded per the above format specification
978 and for each input line returns 1 line starting with OK/ERR/BH result
979 code and optionally followed by additional keywords with more details.
980
cccac0a2 981
41bd17a4 982 General result syntax:
cccac0a2 983
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984 [channel-ID] result keyword=value ...
985
986 Result consists of one of the codes:
987
988 OK
989 the ACL test produced a match.
990
991 ERR
992 the ACL test does not produce a match.
993
994 BH
4ded749e 995 An internal error occurred in the helper, preventing
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996 a result being identified.
997
998 The meaning of 'a match' is determined by your squid.conf
999 access control configuration. See the Squid wiki for details.
cccac0a2 1000
41bd17a4 1001 Defined keywords:
cccac0a2 1002
41bd17a4 1003 user= The users name (login)
5269ec0e 1004
41bd17a4 1005 password= The users password (for login= cache_peer option)
5269ec0e 1006
05e52854 1007 message= Message describing the reason for this response.
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1008 Available as %o in error pages.
1009 Useful on (ERR and BH results).
1010
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1011 tag= Apply a tag to a request. Only sets a tag once,
1012 does not alter existing tags.
5269ec0e 1013
41bd17a4 1014 log= String to be logged in access.log. Available as
cd0fd8a9 1015 %ea in logformat specifications.
934b03fc 1016
cd0fd8a9 1017 clt_conn_tag= Associates a TAG with the client TCP connection.
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1018 Please see url_rewrite_program related documentation
1019 for this kv-pair.
457857fe 1020
05e52854 1021 Any keywords may be sent on any response whether OK, ERR or BH.
6a566b9c 1022
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AJ
1023 All response keyword values need to be a single token with URL
1024 escaping, or enclosed in double quotes (") and escaped using \ on
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1025 any double quotes or \ characters within the value. The wrapping
1026 double quotes are removed before the value is interpreted by Squid.
1027 \r and \n are also replace by CR and LF.
1e5562e3 1028
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1029 Some example key values:
1030
5269ec0e 1031 user=John%20Smith
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1032 user="John Smith"
1033 user="J. \"Bob\" Smith"
cccac0a2 1034DOC_END
1035
41bd17a4 1036NAME: acl
1037TYPE: acl
1038LOC: Config.aclList
cb4f4424 1039IF USE_OPENSSL
cf1c09f6
CT
1040DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
1041DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
1042DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
1043DEFAULT: ssl::certUntrusted ssl_error X509_V_ERR_INVALID_CA X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY X509_V_ERR_CERT_UNTRUSTED
1044DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
1045ENDIF
1f5bd0a4 1046DEFAULT: all src all
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1047DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
1048DEFAULT: localhost src 127.0.0.1/32 ::1
d959846f 1049DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1/128 ::/128
2c56ee3c 1050DEFAULT: CONNECT method CONNECT
29503899 1051DEFAULT_DOC: ACLs all, manager, localhost, to_localhost, and CONNECT are predefined.
cccac0a2 1052DOC_START
41bd17a4 1053 Defining an Access List
cccac0a2 1054
9603207d 1055 Every access list definition must begin with an aclname and acltype,
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AJ
1056 followed by either type-specific arguments or a quoted filename that
1057 they are read from.
cccac0a2 1058
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1059 acl aclname acltype argument ...
1060 acl aclname acltype "file" ...
cccac0a2 1061
375eeb3b 1062 When using "file", the file should contain one item per line.
cccac0a2 1063
76ee67ac
CT
1064
1065 ACL Options
1066
1067 Some acl types supports options which changes their default behaviour:
0f987978
CT
1068
1069 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
1070 case-insensitive, use the -i option. To return case-sensitive
1071 use the +i option between patterns, or make a new ACL line
9603207d 1072 without -i.
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CT
1073
1074 -n Disable lookups and address type conversions. If lookup or
1075 conversion is required because the parameter type (IP or
1076 domain name) does not match the message address type (domain
1077 name or IP), then the ACL would immediately declare a mismatch
1078 without any warnings or lookups.
1079
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1080 -m[=delimiters]
1081 Perform a list membership test, interpreting values as
1082 comma-separated token lists and matching against individual
9603207d 1083 tokens instead of whole values.
76ee67ac
CT
1084 The optional "delimiters" parameter specifies one or more
1085 alternative non-alphanumeric delimiter characters.
1086 non-alphanumeric delimiter characters.
1087
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CT
1088 -- Used to stop processing all options, in the case the first acl
1089 value has '-' character as first character (for example the '-'
1090 is a valid domain name)
cccac0a2 1091
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FC
1092 Some acl types require suspending the current request in order
1093 to access some external data source.
1094 Those which do are marked with the tag [slow], those which
1095 don't are marked as [fast].
1096 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
1097 for further information
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1098
1099 ***** ACL TYPES AVAILABLE *****
1100
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1101 acl aclname src ip-address/mask ... # clients IP address [fast]
1102 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
0f987978 1103 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
1e40905d 1104 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
cccac0a2 1105
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1106if USE_SQUID_EUI
1107 acl aclname arp mac-address ...
1108 acl aclname eui64 eui64-address ...
b3567eb5 1109 # [fast]
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1110 # MAC (EUI-48) and EUI-64 addresses use xx:xx:xx:xx:xx:xx notation.
1111 #
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1112 # The 'arp' ACL code is not portable to all operating systems.
1113 # It works on Linux, Solaris, Windows, FreeBSD, and some other
1114 # BSD variants.
41bd17a4 1115 #
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1116 # The eui_lookup directive is required to be 'on' (the default)
1117 # and Squid built with --enable-eui for MAC/EUI addresses to be
1118 # available for this ACL.
1119 #
1120 # Squid can only determine the MAC/EUI address for IPv4
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1121 # clients that are on the same subnet. If the client is on a
1122 # different subnet, then Squid cannot find out its address.
1123 #
a85f0df5 1124 # IPv6 protocol does not contain ARP. MAC/EUI is either
abe01913 1125 # encoded directly in the IPv6 address or not available.
a85f0df5 1126endif
653d9927 1127 acl aclname clientside_mark mark[/mask] ...
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1128 # matches CONNMARK of an accepted connection [fast]
1129 # DEPRECATED. Use the 'client_connection_mark' instead.
1130
1131 acl aclname client_connection_mark mark[/mask] ...
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A
1132 # matches CONNMARK of an accepted connection [fast]
1133 #
1134 # mark and mask are unsigned integers (hex, octal, or decimal).
1135 # If multiple marks are given, then the ACL matches if at least
1136 # one mark matches.
1137 #
1138 # Uses netfilter-conntrack library.
1139 # Requires building Squid with --enable-linux-netfilter.
1140 #
1141 # The client, various intermediaries, and Squid itself may set
1142 # CONNMARK at various times. The last CONNMARK set wins. This ACL
1143 # checks the mark present on an accepted connection or set by
1144 # Squid afterwards, depending on the ACL check timing. This ACL
1145 # effectively ignores any mark set by other agents after Squid has
1146 # accepted the connection.
1147
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FC
1148 acl aclname srcdomain .foo.com ...
1149 # reverse lookup, from client IP [slow]
0f987978 1150 acl aclname dstdomain [-n] .foo.com ...
e38c7724 1151 # Destination server from URL [fast]
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FC
1152 acl aclname srcdom_regex [-i] \.foo\.com ...
1153 # regex matching client name [slow]
0f987978 1154 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
e38c7724 1155 # regex matching server [fast]
b3567eb5 1156 #
41bd17a4 1157 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
1158 # based URL is used and no match is found. The name "none" is used
1159 # if the reverse lookup fails.
9bc73deb 1160
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1161 acl aclname src_as number ...
1162 acl aclname dst_as number ...
b3567eb5 1163 # [fast]
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1164 # Except for access control, AS numbers can be used for
1165 # routing of requests to specific caches. Here's an
1166 # example for routing all requests for AS#1241 and only
1167 # those to mycache.mydomain.net:
1168 # acl asexample dst_as 1241
1169 # cache_peer_access mycache.mydomain.net allow asexample
1170 # cache_peer_access mycache_mydomain.net deny all
7f7db318 1171
6db78a1a 1172 acl aclname peername myPeer ...
a85f0df5 1173 acl aclname peername_regex [-i] regex-pattern ...
b3567eb5 1174 # [fast]
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AJ
1175 # match against a named cache_peer entry
1176 # set unique name= on cache_peer lines for reliable use.
1177
375eeb3b 1178 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
b3567eb5 1179 # [fast]
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1180 # day-abbrevs:
1181 # S - Sunday
1182 # M - Monday
1183 # T - Tuesday
1184 # W - Wednesday
1185 # H - Thursday
1186 # F - Friday
1187 # A - Saturday
1188 # h1:m1 must be less than h2:m2
1189
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1190 acl aclname url_regex [-i] ^http:// ...
1191 # regex matching on whole URL [fast]
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1192 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
1193 # regex matching on URL login field
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FC
1194 acl aclname urlpath_regex [-i] \.gif$ ...
1195 # regex matching on URL path [fast]
e988aa40 1196
b3567eb5 1197 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
2f8abb64 1198 # ranges are allowed
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1199 acl aclname localport 3128 ... # TCP port the client connected to [fast]
1200 # NP: for interception mode this is usually '80'
1201
3cc0f4e7 1202 acl aclname myportname 3128 ... # *_port name [fast]
e988aa40 1203
b3567eb5 1204 acl aclname proto HTTP FTP ... # request protocol [fast]
9603207d 1205
b3567eb5 1206 acl aclname method GET POST ... # HTTP request method [fast]
e988aa40 1207
9603207d 1208 acl aclname http_status 200 301 500- 400-403 ...
b3567eb5 1209 # status code in reply [fast]
e988aa40 1210
375eeb3b 1211 acl aclname browser [-i] regexp ...
b3567eb5 1212 # pattern match on User-Agent header (see also req_header below) [fast]
e988aa40 1213
375eeb3b 1214 acl aclname referer_regex [-i] regexp ...
b3567eb5 1215 # pattern match on Referer header [fast]
41bd17a4 1216 # Referer is highly unreliable, so use with care
e988aa40 1217
d4c6acac 1218 acl aclname ident [-i] username ...
41bd17a4 1219 acl aclname ident_regex [-i] pattern ...
b3567eb5 1220 # string match on ident output [slow]
41bd17a4 1221 # use REQUIRED to accept any non-null ident.
cf5cc17e 1222
41bd17a4 1223 acl aclname proxy_auth [-i] username ...
1224 acl aclname proxy_auth_regex [-i] pattern ...
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FC
1225 # perform http authentication challenge to the client and match against
1226 # supplied credentials [slow]
1227 #
1228 # takes a list of allowed usernames.
41bd17a4 1229 # use REQUIRED to accept any valid username.
1230 #
b3567eb5 1231 # Will use proxy authentication in forward-proxy scenarios, and plain
2f8abb64 1232 # http authentication in reverse-proxy scenarios
b3567eb5 1233 #
41bd17a4 1234 # NOTE: when a Proxy-Authentication header is sent but it is not
1235 # needed during ACL checking the username is NOT logged
1236 # in access.log.
1237 #
1238 # NOTE: proxy_auth requires a EXTERNAL authentication program
1239 # to check username/password combinations (see
1240 # auth_param directive).
1241 #
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1242 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
1243 # as the browser needs to be configured for using a proxy in order
41bd17a4 1244 # to respond to proxy authentication.
8e8d4f30 1245
41bd17a4 1246 acl aclname snmp_community string ...
b3567eb5 1247 # A community string to limit access to your SNMP Agent [fast]
41bd17a4 1248 # Example:
1249 #
1250 # acl snmppublic snmp_community public
934b03fc 1251
41bd17a4 1252 acl aclname maxconn number
1253 # This will be matched when the client's IP address has
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1254 # more than <number> TCP connections established. [fast]
1255 # NOTE: This only measures direct TCP links so X-Forwarded-For
1256 # indirect clients are not counted.
1e5562e3 1257
41bd17a4 1258 acl aclname max_user_ip [-s] number
1259 # This will be matched when the user attempts to log in from more
1260 # than <number> different ip addresses. The authenticate_ip_ttl
b3567eb5 1261 # parameter controls the timeout on the ip entries. [fast]
41bd17a4 1262 # If -s is specified the limit is strict, denying browsing
1263 # from any further IP addresses until the ttl has expired. Without
1264 # -s Squid will just annoy the user by "randomly" denying requests.
1265 # (the counter is reset each time the limit is reached and a
1266 # request is denied)
1267 # NOTE: in acceleration mode or where there is mesh of child proxies,
1268 # clients may appear to come from multiple addresses if they are
1269 # going through proxy farms, so a limit of 1 may cause user problems.
cccac0a2 1270
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1271 acl aclname random probability
1272 # Pseudo-randomly match requests. Based on the probability given.
1273 # Probability may be written as a decimal (0.333), fraction (1/3)
1274 # or ratio of matches:non-matches (3:5).
1275
375eeb3b 1276 acl aclname req_mime_type [-i] mime-type ...
41bd17a4 1277 # regex match against the mime type of the request generated
1278 # by the client. Can be used to detect file upload or some
b3567eb5 1279 # types HTTP tunneling requests [fast]
41bd17a4 1280 # NOTE: This does NOT match the reply. You cannot use this
1281 # to match the returned file type.
cccac0a2 1282
41bd17a4 1283 acl aclname req_header header-name [-i] any\.regex\.here
1284 # regex match against any of the known request headers. May be
1285 # thought of as a superset of "browser", "referer" and "mime-type"
b3567eb5 1286 # ACL [fast]
cccac0a2 1287
375eeb3b 1288 acl aclname rep_mime_type [-i] mime-type ...
41bd17a4 1289 # regex match against the mime type of the reply received by
1290 # squid. Can be used to detect file download or some
b3567eb5 1291 # types HTTP tunneling requests. [fast]
41bd17a4 1292 # NOTE: This has no effect in http_access rules. It only has
1293 # effect in rules that affect the reply data stream such as
1294 # http_reply_access.
cccac0a2 1295
41bd17a4 1296 acl aclname rep_header header-name [-i] any\.regex\.here
1297 # regex match against any of the known reply headers. May be
1298 # thought of as a superset of "browser", "referer" and "mime-type"
b3567eb5 1299 # ACLs [fast]
cccac0a2 1300
375eeb3b 1301 acl aclname external class_name [arguments...]
41bd17a4 1302 # external ACL lookup via a helper class defined by the
b3567eb5 1303 # external_acl_type directive [slow]
cccac0a2 1304
41bd17a4 1305 acl aclname user_cert attribute values...
1306 # match against attributes in a user SSL certificate
2927ae41 1307 # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
cccac0a2 1308
41bd17a4 1309 acl aclname ca_cert attribute values...
1310 # match against attributes a users issuing CA SSL certificate
2927ae41 1311 # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
cccac0a2 1312
d4c6acac 1313 acl aclname ext_user [-i] username ...
41bd17a4 1314 acl aclname ext_user_regex [-i] pattern ...
b3567eb5 1315 # string match on username returned by external acl helper [slow]
41bd17a4 1316 # use REQUIRED to accept any non-null user name.
b3567eb5 1317
0ab50441 1318 acl aclname tag tagvalue ...
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1319 # string match on tag returned by external acl helper [fast]
1320 # DEPRECATED. Only the first tag will match with this ACL.
1321 # Use the 'note' ACL instead for handling multiple tag values.
cccac0a2 1322
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1323 acl aclname hier_code codename ...
1324 # string match against squid hierarchy code(s); [fast]
1325 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1326 #
1327 # NOTE: This has no effect in http_access rules. It only has
1328 # effect in rules that affect the reply data stream such as
1329 # http_reply_access.
1330
76ee67ac 1331 acl aclname note [-m[=delimiters]] name [value ...]
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1332 # match transaction annotation [fast]
1333 # Without values, matches any annotation with a given name.
1334 # With value(s), matches any annotation with a given name that
1335 # also has one of the given values.
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1336 # If the -m flag is used, then the value of the named
1337 # annotation is interpreted as a list of tokens, and the ACL
1338 # matches individual name=token pairs rather than whole
1339 # name=value pairs. See "ACL Options" above for more info.
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1340 # Annotation sources include note and adaptation_meta directives
1341 # as well as helper and eCAP responses.
1342
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1343 acl aclname annotate_transaction [-m[=delimiters]] key=value ...
1344 acl aclname annotate_transaction [-m[=delimiters]] key+=value ...
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1345 # Always matches. [fast]
1346 # Used for its side effect: This ACL immediately adds a
1347 # key=value annotation to the current master transaction.
1348 # The added annotation can then be tested using note ACL and
1349 # logged (or sent to helpers) using %note format code.
1350 #
1351 # Annotations can be specified using replacement and addition
1352 # formats. The key=value form replaces old same-key annotation
1353 # value(s). The key+=value form appends a new value to the old
1354 # same-key annotation. Both forms create a new key=value
1355 # annotation if no same-key annotation exists already. If
1356 # -m flag is used, then the value is interpreted as a list
1357 # and the annotation will contain key=token pair(s) instead of the
1358 # whole key=value pair.
1359 #
1360 # This ACL is especially useful for recording complex multi-step
1361 # ACL-driven decisions. For example, the following configuration
1362 # avoids logging transactions accepted after aclX matched:
1363 #
1364 # # First, mark transactions accepted after aclX matched
1365 # acl markSpecial annotate_transaction special=true
1366 # http_access allow acl001
1367 # ...
1368 # http_access deny acl100
1369 # http_access allow aclX markSpecial
1370 #
1371 # # Second, do not log marked transactions:
1372 # acl markedSpecial note special true
1373 # access_log ... deny markedSpecial
1374 #
1375 # # Note that the following would not have worked because aclX
1376 # # alone does not determine whether the transaction was allowed:
1377 # access_log ... deny aclX # Wrong!
1378 #
1379 # Warning: This ACL annotates the transaction even when negated
1380 # and even if subsequent ACLs fail to match. For example, the
1381 # following three rules will have exactly the same effect as far
1382 # as annotations set by the "mark" ACL are concerned:
1383 #
1384 # some_directive acl1 ... mark # rule matches if mark is reached
1385 # some_directive acl1 ... !mark # rule never matches
1386 # some_directive acl1 ... mark !all # rule never matches
1387
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1388 acl aclname annotate_client [-m[=delimiters]] key=value ...
1389 acl aclname annotate_client [-m[=delimiters]] key+=value ...
75d47340 1390 #
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1391 # Always matches. [fast]
1392 # Used for its side effect: This ACL immediately adds a
1393 # key=value annotation to the current client-to-Squid
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1394 # connection. Connection annotations are propagated to the current
1395 # and all future master transactions on the annotated connection.
1396 # See the annotate_transaction ACL for details.
1397 #
1398 # For example, the following configuration avoids rewriting URLs
1399 # of transactions bumped by SslBump:
1400 #
1401 # # First, mark bumped connections:
1402 # acl markBumped annotate_client bumped=true
1403 # ssl_bump peek acl1
1404 # ssl_bump stare acl2
1405 # ssl_bump bump acl3 markBumped
1406 # ssl_bump splice all
1407 #
1408 # # Second, do not send marked transactions to the redirector:
1409 # acl markedBumped note bumped true
1410 # url_rewrite_access deny markedBumped
1411 #
1412 # # Note that the following would not have worked because acl3 alone
1413 # # does not determine whether the connection is going to be bumped:
1414 # url_rewrite_access deny acl3 # Wrong!
1415
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1416 acl aclname adaptation_service service ...
1417 # Matches the name of any icap_service, ecap_service,
1418 # adaptation_service_set, or adaptation_service_chain that Squid
1419 # has used (or attempted to use) for the master transaction.
1420 # This ACL must be defined after the corresponding adaptation
1421 # service is named in squid.conf. This ACL is usable with
1422 # adaptation_meta because it starts matching immediately after
1423 # the service has been selected for adaptation.
1424
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1425 acl aclname transaction_initiator initiator ...
1426 # Matches transaction's initiator [fast]
1427 #
1428 # Supported initiators are:
1429 # esi: matches transactions fetching ESI resources
1430 # certificate-fetching: matches transactions fetching
1431 # a missing intermediate TLS certificate
1432 # cache-digest: matches transactions fetching Cache Digests
1433 # from a cache_peer
1434 # htcp: matches HTCP requests from peers
1435 # icp: matches ICP requests to peers
1436 # icmp: matches ICMP RTT database (NetDB) requests to peers
1437 # asn: matches asns db requests
1438 # internal: matches any of the above
1439 # client: matches transactions containing an HTTP or FTP
1440 # client request received at a Squid *_port
1441 # all: matches any transaction, including internal transactions
1442 # without a configurable initiator and hopefully rare
1443 # transactions without a known-to-Squid initiator
1444 #
1445 # Multiple initiators are ORed.
1446
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1447 acl aclname has component
1448 # matches a transaction "component" [fast]
1449 #
1450 # Supported transaction components are:
1451 # request: transaction has a request header (at least)
1452 # response: transaction has a response header (at least)
1453 # ALE: transaction has an internally-generated Access Log Entry
1454 # structure; bugs notwithstanding, all transaction have it
1455 #
1456 # For example, the following configuration helps when dealing with HTTP
1457 # clients that close connections without sending a request header:
1458 #
1459 # acl hasRequest has request
1460 # acl logMe note important_transaction
1461 # # avoid "logMe ACL is used in context without an HTTP request" warnings
1462 # access_log ... logformat=detailed hasRequest logMe
1463 # # log request-less transactions, instead of ignoring them
1464 # access_log ... logformat=brief !hasRequest
1465 #
1466 # Multiple components are not supported for one "acl" rule, but
1467 # can be specified (and are ORed) using multiple same-name rules:
1468 #
1469 # # OK, this strange logging daemon needs request or response,
1470 # # but can work without either a request or a response:
1471 # acl hasWhatMyLoggingDaemonNeeds has request
1472 # acl hasWhatMyLoggingDaemonNeeds has response
1473
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1474acl aclname at_step step
1475 # match against the current request processing step [fast]
1476 # Valid steps are:
1477 # GeneratingCONNECT: Generating HTTP CONNECT request headers
1478IF USE_OPENSSL
1479 # The following ssl_bump processing steps are recognized:
1480 # SslBump1: After getting TCP-level and HTTP CONNECT info.
1481 # SslBump2: After getting SSL Client Hello info.
1482 # SslBump3: After getting SSL Server Hello info.
1483ENDIF
1484
cb4f4424 1485IF USE_OPENSSL
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1486 acl aclname ssl_error errorname
1487 # match against SSL certificate validation error [fast]
cf1c09f6 1488 #
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1489 # When used with sslproxy_cert_error, this ACL tests a single
1490 # certificate validation error currently being evaluated by that
1491 # directive. When used with slproxy_cert_sign or sslproxy_cert_adapt,
1492 # the ACL tests all past certificate validation errors associated with
1493 # the current Squid-to-server connection (attempt). This ACL is not yet
1494 # supported for use with other directives.
1495 #
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1496 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1497 # template file.
cf1c09f6 1498 #
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1499 # The following can be used as shortcuts for certificate properties:
1500 # [ssl::]certHasExpired: the "not after" field is in the past
1501 # [ssl::]certNotYetValid: the "not before" field is in the future
1502 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1503 # [ssl::]certSelfSigned: The certificate is self signed.
1504 # [ssl::]certDomainMismatch: The certificate CN domain does not
1505 # match the name the name of the host we are connecting to.
1506 #
1507 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1508 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1509 # predefined ACLs, just like the 'all' ACL.
00352183 1510
72b12f9e 1511 acl aclname server_cert_fingerprint [-sha1] fingerprint
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1512 # match against server SSL certificate fingerprint [fast]
1513 #
9603207d 1514 # The fingerprint is the digest of the DER encoded version
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1515 # of the whole certificate. The user should use the form: XX:XX:...
1516 # Optional argument specifies the digest algorithm to use.
1517 # The SHA1 digest algorithm is the default and is currently
1518 # the only algorithm supported (-sha1).
5d65362c 1519
4f6990ec 1520 acl aclname ssl::server_name [option] .foo.com ...
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1521 # matches server name obtained from various sources [fast]
1522 #
4f6990ec 1523 # The ACL computes server name(s) using such information sources as
9603207d 1524 # CONNECT request URI, TLS client SNI, and TLS server certificate
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1525 # subject (CN and SubjectAltName). The computed server name(s) usually
1526 # change with each SslBump step, as more info becomes available:
1527 # * SNI is used as the server name instead of the request URI,
1528 # * subject name(s) from the server certificate (CN and
1529 # SubjectAltName) are used as the server names instead of SNI.
1530 #
1531 # When the ACL computes multiple server names, matching any single
1532 # computed name is sufficient for the ACL to match.
1533 #
1534 # The "none" name can be used to match transactions where the ACL
8d9e6d7f 1535 # could not compute the server name using any information source
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1536 # that was both available and allowed to be used by the ACL options at
1537 # the ACL evaluation time.
1538 #
1539 # Unlike dstdomain, this ACL does not perform DNS lookups.
1540 #
9603207d 1541 # An ACL option below may be used to restrict what information
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1542 # sources are used to extract the server names from:
1543 #
1544 # --client-requested
1545 # The server name is SNI regardless of what the server says.
1546 # --server-provided
1547 # The server name(s) are the certificate subject name(s), regardless
1548 # of what the client has requested. If the server certificate is
1549 # unavailable, then the name is "none".
1550 # --consensus
1551 # The server name is either SNI (if SNI matches at least one of the
1552 # certificate subject names) or "none" (otherwise). When the server
1553 # certificate is unavailable, the consensus server name is SNI.
1554 #
1555 # Combining multiple options in one ACL is a fatal configuration
1556 # error.
1557 #
1558 # For all options: If no SNI is available, then the CONNECT request
1559 # target (a.k.a. URI) is used instead of SNI (for an intercepted
1560 # connection, this target is the destination IP address).
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1561
1562 acl aclname ssl::server_name_regex [-i] \.foo\.com ...
1563 # regex matches server name obtained from various sources [fast]
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1564
1565 acl aclname connections_encrypted
1566 # matches transactions with all HTTP messages received over TLS
1567 # transport connections. [fast]
1568 #
1569 # The master transaction deals with HTTP messages received from
1570 # various sources. All sources used by the master transaction in the
1571 # past are considered by the ACL. The following rules define whether
1572 # a given message source taints the entire master transaction,
1573 # resulting in ACL mismatches:
1574 #
1575 # * The HTTP client transport connection is not TLS.
1576 # * An adaptation service connection-encryption flag is off.
1577 # * The peer or origin server transport connection is not TLS.
1578 #
1579 # Caching currently does not affect these rules. This cache ignorance
1580 # implies that only the current HTTP client transport and REQMOD
1581 # services status determine whether this ACL matches a from-cache
1582 # transaction. The source of the cached response does not have any
1583 # effect on future transaction that use the cached response without
1584 # revalidation. This may change.
1585 #
1586 # DNS, ICP, and HTCP exchanges during the master transaction do not
1587 # affect these rules.
cf1c09f6 1588ENDIF
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1589 acl aclname any-of acl1 acl2 ...
1590 # match any one of the acls [fast or slow]
1591 # The first matching ACL stops further ACL evaluation.
1592 #
1593 # ACLs from multiple any-of lines with the same name are ORed.
1594 # For example, A = (a1 or a2) or (a3 or a4) can be written as
1595 # acl A any-of a1 a2
1596 # acl A any-of a3 a4
1597 #
1598 # This group ACL is fast if all evaluated ACLs in the group are fast
1599 # and slow otherwise.
1600
9603207d 1601 acl aclname all-of acl1 acl2 ...
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1602 # match all of the acls [fast or slow]
1603 # The first mismatching ACL stops further ACL evaluation.
1604 #
1605 # ACLs from multiple all-of lines with the same name are ORed.
1606 # For example, B = (b1 and b2) or (b3 and b4) can be written as
1607 # acl B all-of b1 b2
1608 # acl B all-of b3 b4
1609 #
1610 # This group ACL is fast if all evaluated ACLs in the group are fast
1611 # and slow otherwise.
cf1c09f6 1612
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1613 Examples:
1614 acl macaddress arp 09:00:2b:23:45:67
1615 acl myexample dst_as 1241
1616 acl password proxy_auth REQUIRED
1617 acl fileupload req_mime_type -i ^multipart/form-data$
1618 acl javascript rep_mime_type -i ^application/x-javascript$
cccac0a2 1619
47f0eaea 1620CONFIG_START
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1621#
1622# Recommended minimum configuration:
1623#
e0855596 1624
ee776778 1625# Example rule allowing access from your local networks.
1626# Adapt to list your (internal) IP networks from where browsing
1627# should be allowed
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1628acl localnet src 0.0.0.1-0.255.255.255 # RFC 1122 "this" network (LAN)
1629acl localnet src 10.0.0.0/8 # RFC 1918 local private network (LAN)
1630acl localnet src 100.64.0.0/10 # RFC 6598 shared address space (CGN)
7c392424 1631acl localnet src 169.254.0.0/16 # RFC 3927 link-local (directly plugged) machines
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1632acl localnet src 172.16.0.0/12 # RFC 1918 local private network (LAN)
1633acl localnet src 192.168.0.0/16 # RFC 1918 local private network (LAN)
1634acl localnet src fc00::/7 # RFC 4193 local private network range
1635acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
e0855596 1636
41bd17a4 1637acl SSL_ports port 443
1638acl Safe_ports port 80 # http
1639acl Safe_ports port 21 # ftp
1640acl Safe_ports port 443 # https
1641acl Safe_ports port 70 # gopher
1642acl Safe_ports port 210 # wais
1643acl Safe_ports port 1025-65535 # unregistered ports
1644acl Safe_ports port 280 # http-mgmt
1645acl Safe_ports port 488 # gss-http
1646acl Safe_ports port 591 # filemaker
1647acl Safe_ports port 777 # multiling http
47f0eaea 1648CONFIG_END
41bd17a4 1649DOC_END
cccac0a2 1650
d3d92daa 1651NAME: proxy_protocol_access
3d674977 1652TYPE: acl_access
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1653LOC: Config.accessList.proxyProtocol
1654DEFAULT: none
c390580b 1655DEFAULT_DOC: all TCP connections to ports with require-proxy-header will be denied
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1656DOC_START
1657 Determine which client proxies can be trusted to provide correct
1658 information regarding real client IP address using PROXY protocol.
1659
1660 Requests may pass through a chain of several other proxies
1661 before reaching us. The original source details may by sent in:
1662 * HTTP message Forwarded header, or
1663 * HTTP message X-Forwarded-For header, or
1664 * PROXY protocol connection header.
1665
1666 This directive is solely for validating new PROXY protocol
1667 connections received from a port flagged with require-proxy-header.
1668 It is checked only once after TCP connection setup.
1669
1670 A deny match results in TCP connection closure.
1671
1672 An allow match is required for Squid to permit the corresponding
1673 TCP connection, before Squid even looks for HTTP request headers.
1674 If there is an allow match, Squid starts using PROXY header information
1675 to determine the source address of the connection for all future ACL
1676 checks, logging, etc.
1677
1678 SECURITY CONSIDERATIONS:
1679
c390580b 1680 Any host from which we accept client IP details can place
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1681 incorrect information in the relevant header, and Squid
1682 will use the incorrect information as if it were the
1683 source address of the request. This may enable remote
1684 hosts to bypass any access control restrictions that are
1685 based on the client's source addresses.
1686
1687 This clause only supports fast acl types.
1688 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1689DOC_END
1690
1691NAME: follow_x_forwarded_for
1692TYPE: acl_access
1693IFDEF: FOLLOW_X_FORWARDED_FOR
3d674977 1694LOC: Config.accessList.followXFF
3d674977 1695DEFAULT_IF_NONE: deny all
9353df52 1696DEFAULT_DOC: X-Forwarded-For header will be ignored.
3d674977 1697DOC_START
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1698 Determine which client proxies can be trusted to provide correct
1699 information regarding real client IP address.
1700
3d674977 1701 Requests may pass through a chain of several other proxies
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1702 before reaching us. The original source details may by sent in:
1703 * HTTP message Forwarded header, or
1704 * HTTP message X-Forwarded-For header, or
1705 * PROXY protocol connection header.
3d674977 1706
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1707 PROXY protocol connections are controlled by the proxy_protocol_access
1708 directive which is checked before this.
1709
3d674977 1710 If a request reaches us from a source that is allowed by this
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1711 directive, then we trust the information it provides regarding
1712 the IP of the client it received from (if any).
1713
1714 For the purpose of ACLs used in this directive the src ACL type always
1715 matches the address we are testing and srcdomain matches its rDNS.
1716
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1717 On each HTTP request Squid checks for X-Forwarded-For header fields.
1718 If found the header values are iterated in reverse order and an allow
1719 match is required for Squid to continue on to the next value.
1720 The verification ends when a value receives a deny match, cannot be
1721 tested, or there are no more values to test.
1722 NOTE: Squid does not yet follow the Forwarded HTTP header.
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1723
1724 The end result of this process is an IP address that we will
1725 refer to as the indirect client address. This address may
57d76dd4 1726 be treated as the client address for access control, ICAP, delay
3d674977 1727 pools and logging, depending on the acl_uses_indirect_client,
9603207d 1728 icap_uses_indirect_client, delay_pool_uses_indirect_client,
96d64448 1729 log_uses_indirect_client and tproxy_uses_indirect_client options.
3d674977 1730
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1731 This clause only supports fast acl types.
1732 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1733
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1734 SECURITY CONSIDERATIONS:
1735
c390580b 1736 Any host from which we accept client IP details can place
70a16fea 1737 incorrect information in the relevant header, and Squid
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1738 will use the incorrect information as if it were the
1739 source address of the request. This may enable remote
1740 hosts to bypass any access control restrictions that are
1741 based on the client's source addresses.
1742
1743 For example:
1744
1745 acl localhost src 127.0.0.1
1746 acl my_other_proxy srcdomain .proxy.example.com
1747 follow_x_forwarded_for allow localhost
1748 follow_x_forwarded_for allow my_other_proxy
1749DOC_END
1750
1751NAME: acl_uses_indirect_client
1752COMMENT: on|off
1753TYPE: onoff
1754IFDEF: FOLLOW_X_FORWARDED_FOR
1755DEFAULT: on
1756LOC: Config.onoff.acl_uses_indirect_client
1757DOC_START
1758 Controls whether the indirect client address
1759 (see follow_x_forwarded_for) is used instead of the
1760 direct client address in acl matching.
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1761
1762 NOTE: maxconn ACL considers direct TCP links and indirect
1763 clients will always have zero. So no match.
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1764DOC_END
1765
1766NAME: delay_pool_uses_indirect_client
1767COMMENT: on|off
1768TYPE: onoff
9a0a18de 1769IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
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1770DEFAULT: on
1771LOC: Config.onoff.delay_pool_uses_indirect_client
1772DOC_START
1773 Controls whether the indirect client address
1774 (see follow_x_forwarded_for) is used instead of the
1775 direct client address in delay pools.
1776DOC_END
1777
1778NAME: log_uses_indirect_client
1779COMMENT: on|off
1780TYPE: onoff
1781IFDEF: FOLLOW_X_FORWARDED_FOR
1782DEFAULT: on
1783LOC: Config.onoff.log_uses_indirect_client
1784DOC_START
1785 Controls whether the indirect client address
1786 (see follow_x_forwarded_for) is used instead of the
1787 direct client address in the access log.
1788DOC_END
1789
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1790NAME: tproxy_uses_indirect_client
1791COMMENT: on|off
1792TYPE: onoff
1793IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
4d7ab5a2 1794DEFAULT: off
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1795LOC: Config.onoff.tproxy_uses_indirect_client
1796DOC_START
1797 Controls whether the indirect client address
1798 (see follow_x_forwarded_for) is used instead of the
1799 direct client address when spoofing the outgoing client.
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1800
1801 This has no effect on requests arriving in non-tproxy
1802 mode ports.
1803
1804 SECURITY WARNING: Usage of this option is dangerous
1805 and should not be used trivially. Correct configuration
16ae256c 1806 of follow_x_forwarded_for with a limited set of trusted
4d7ab5a2 1807 sources is required to prevent abuse of your proxy.
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1808DOC_END
1809
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1810NAME: spoof_client_ip
1811TYPE: acl_access
1812LOC: Config.accessList.spoof_client_ip
1813DEFAULT: none
1814DEFAULT_DOC: Allow spoofing on all TPROXY traffic.
1815DOC_START
1816 Control client IP address spoofing of TPROXY traffic based on
1817 defined access lists.
1818
1819 spoof_client_ip allow|deny [!]aclname ...
1820
1821 If there are no "spoof_client_ip" lines present, the default
1822 is to "allow" spoofing of any suitable request.
1823
1824 Note that the cache_peer "no-tproxy" option overrides this ACL.
1825
1826 This clause supports fast acl types.
1827 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1828DOC_END
1829
41bd17a4 1830NAME: http_access
1831TYPE: acl_access
1832LOC: Config.accessList.http
41bd17a4 1833DEFAULT_IF_NONE: deny all
638402dd 1834DEFAULT_DOC: Deny, unless rules exist in squid.conf.
41bd17a4 1835DOC_START
1836 Allowing or Denying access based on defined access lists
cccac0a2 1837
8a2f40dd 1838 To allow or deny a message received on an HTTP, HTTPS, or FTP port:
41bd17a4 1839 http_access allow|deny [!]aclname ...
cccac0a2 1840
41bd17a4 1841 NOTE on default values:
cccac0a2 1842
41bd17a4 1843 If there are no "access" lines present, the default is to deny
1844 the request.
cccac0a2 1845
41bd17a4 1846 If none of the "access" lines cause a match, the default is the
1847 opposite of the last line in the list. If the last line was
1848 deny, the default is allow. Conversely, if the last line
1849 is allow, the default will be deny. For these reasons, it is a
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1850 good idea to have an "deny all" entry at the end of your access
1851 lists to avoid potential confusion.
cccac0a2 1852
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1853 This clause supports both fast and slow acl types.
1854 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1855
47f0eaea 1856CONFIG_START
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1857
1858#
1859# Recommended minimum Access Permission configuration:
41bd17a4 1860#
e0855596 1861# Deny requests to certain unsafe ports
41bd17a4 1862http_access deny !Safe_ports
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1863
1864# Deny CONNECT to other than secure SSL ports
41bd17a4 1865http_access deny CONNECT !SSL_ports
e0855596 1866
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1867# Only allow cachemgr access from localhost
1868http_access allow localhost manager
1869http_access deny manager
1870
41bd17a4 1871# We strongly recommend the following be uncommented to protect innocent
1872# web applications running on the proxy server who think the only
1873# one who can access services on "localhost" is a local user
1874#http_access deny to_localhost
e0855596 1875
41bd17a4 1876#
1877# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
e0855596 1878#
c8f4eac4 1879
ee776778 1880# Example rule allowing access from your local networks.
1881# Adapt localnet in the ACL section to list your (internal) IP networks
1882# from where browsing should be allowed
1883http_access allow localnet
afb33856 1884http_access allow localhost
7d90757b 1885
41bd17a4 1886# And finally deny all other access to this proxy
1887http_access deny all
47f0eaea 1888CONFIG_END
41bd17a4 1889DOC_END
7d90757b 1890
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1891NAME: adapted_http_access http_access2
1892TYPE: acl_access
1893LOC: Config.accessList.adapted_http
1894DEFAULT: none
638402dd 1895DEFAULT_DOC: Allow, unless rules exist in squid.conf.
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1896DOC_START
1897 Allowing or Denying access based on defined access lists
1898
1899 Essentially identical to http_access, but runs after redirectors
1900 and ICAP/eCAP adaptation. Allowing access control based on their
1901 output.
1902
1903 If not set then only http_access is used.
1904DOC_END
1905
41bd17a4 1906NAME: http_reply_access
1907TYPE: acl_access
1908LOC: Config.accessList.reply
1909DEFAULT: none
638402dd 1910DEFAULT_DOC: Allow, unless rules exist in squid.conf.
41bd17a4 1911DOC_START
1912 Allow replies to client requests. This is complementary to http_access.
cccac0a2 1913
41bd17a4 1914 http_reply_access allow|deny [!] aclname ...
cccac0a2 1915
41bd17a4 1916 NOTE: if there are no access lines present, the default is to allow
638402dd 1917 all replies.
1a224843 1918
41bd17a4 1919 If none of the access lines cause a match the opposite of the
1920 last line will apply. Thus it is good practice to end the rules
1921 with an "allow all" or "deny all" entry.
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1922
1923 This clause supports both fast and slow acl types.
1924 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 1925DOC_END
1926
41bd17a4 1927NAME: icp_access
1928TYPE: acl_access
1929LOC: Config.accessList.icp
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1930DEFAULT: none
1931DEFAULT_DOC: Deny, unless rules exist in squid.conf.
5473c134 1932DOC_START
41bd17a4 1933 Allowing or Denying access to the ICP port based on defined
1934 access lists
5473c134 1935
41bd17a4 1936 icp_access allow|deny [!]aclname ...
5473c134 1937
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1938 NOTE: The default if no icp_access lines are present is to
1939 deny all traffic. This default may cause problems with peers
1940 using ICP.
41bd17a4 1941
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1942 This clause only supports fast acl types.
1943 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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1944
1945# Allow ICP queries from local networks only
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1946#icp_access allow localnet
1947#icp_access deny all
5473c134 1948DOC_END
1949
41bd17a4 1950NAME: htcp_access
1951IFDEF: USE_HTCP
1952TYPE: acl_access
1953LOC: Config.accessList.htcp
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1954DEFAULT: none
1955DEFAULT_DOC: Deny, unless rules exist in squid.conf.
5473c134 1956DOC_START
41bd17a4 1957 Allowing or Denying access to the HTCP port based on defined
1958 access lists
5473c134 1959
41bd17a4 1960 htcp_access allow|deny [!]aclname ...
5473c134 1961
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1962 See also htcp_clr_access for details on access control for
1963 cache purge (CLR) HTCP messages.
5473c134 1964
0b48417e 1965 NOTE: The default if no htcp_access lines are present is to
1966 deny all traffic. This default may cause problems with peers
18191440 1967 using the htcp option.
0b48417e 1968
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1969 This clause only supports fast acl types.
1970 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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1971
1972# Allow HTCP queries from local networks only
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1973#htcp_access allow localnet
1974#htcp_access deny all
41bd17a4 1975DOC_END
5473c134 1976
41bd17a4 1977NAME: htcp_clr_access
1978IFDEF: USE_HTCP
1979TYPE: acl_access
1980LOC: Config.accessList.htcp_clr
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1981DEFAULT: none
1982DEFAULT_DOC: Deny, unless rules exist in squid.conf.
41bd17a4 1983DOC_START
1984 Allowing or Denying access to purge content using HTCP based
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1985 on defined access lists.
1986 See htcp_access for details on general HTCP access control.
5473c134 1987
41bd17a4 1988 htcp_clr_access allow|deny [!]aclname ...
5473c134 1989
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1990 This clause only supports fast acl types.
1991 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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1992
1993# Allow HTCP CLR requests from trusted peers
638402dd 1994acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
41bd17a4 1995htcp_clr_access allow htcp_clr_peer
638402dd 1996htcp_clr_access deny all
5473c134 1997DOC_END
1998
41bd17a4 1999NAME: miss_access
2000TYPE: acl_access
2001LOC: Config.accessList.miss
b8a25eaa 2002DEFAULT: none
638402dd 2003DEFAULT_DOC: Allow, unless rules exist in squid.conf.
5473c134 2004DOC_START
18d1eddf 2005 Determines whether network access is permitted when satisfying a request.
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2006
2007 For example;
2008 to force your neighbors to use you as a sibling instead of
2009 a parent.
5473c134 2010
638402dd 2011 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
41bd17a4 2012 miss_access deny !localclients
638402dd 2013 miss_access allow all
5473c134 2014
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2015 This means only your local clients are allowed to fetch relayed/MISS
2016 replies from the network and all other clients can only fetch cached
2017 objects (HITs).
2018
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2019 The default for this setting allows all clients who passed the
2020 http_access rules to relay via this proxy.
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2021
2022 This clause only supports fast acl types.
2023 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2024DOC_END
2025
2026NAME: ident_lookup_access
2027TYPE: acl_access
2028IFDEF: USE_IDENT
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2029DEFAULT: none
2030DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
4daaf3cb 2031LOC: Ident::TheConfig.identLookup
5473c134 2032DOC_START
41bd17a4 2033 A list of ACL elements which, if matched, cause an ident
2034 (RFC 931) lookup to be performed for this request. For
2035 example, you might choose to always perform ident lookups
2036 for your main multi-user Unix boxes, but not for your Macs
2037 and PCs. By default, ident lookups are not performed for
2038 any requests.
5473c134 2039
41bd17a4 2040 To enable ident lookups for specific client addresses, you
2041 can follow this example:
5473c134 2042
4daaf3cb 2043 acl ident_aware_hosts src 198.168.1.0/24
41bd17a4 2044 ident_lookup_access allow ident_aware_hosts
2045 ident_lookup_access deny all
5473c134 2046
4daaf3cb 2047 Only src type ACL checks are fully supported. A srcdomain
41bd17a4 2048 ACL might work at times, but it will not always provide
2049 the correct result.
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FC
2050
2051 This clause only supports fast acl types.
2052 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2053DOC_END
5473c134 2054
5b0f5383 2055NAME: reply_body_max_size
2056COMMENT: size [acl acl...]
2057TYPE: acl_b_size_t
2058DEFAULT: none
638402dd 2059DEFAULT_DOC: No limit is applied.
5b0f5383 2060LOC: Config.ReplyBodySize
2061DOC_START
2062 This option specifies the maximum size of a reply body. It can be
2063 used to prevent users from downloading very large files, such as
2064 MP3's and movies. When the reply headers are received, the
2065 reply_body_max_size lines are processed, and the first line where
2066 all (if any) listed ACLs are true is used as the maximum body size
2067 for this reply.
2068
2069 This size is checked twice. First when we get the reply headers,
2070 we check the content-length value. If the content length value exists
2071 and is larger than the allowed size, the request is denied and the
2072 user receives an error message that says "the request or reply
2073 is too large." If there is no content-length, and the reply
2074 size exceeds this limit, the client's connection is just closed
2075 and they will receive a partial reply.
2076
2077 WARNING: downstream caches probably can not detect a partial reply
2078 if there is no content-length header, so they will cache
2079 partial responses and give them out as hits. You should NOT
2080 use this option if you have downstream caches.
2081
2082 WARNING: A maximum size smaller than the size of squid's error messages
2083 will cause an infinite loop and crash squid. Ensure that the smallest
2084 non-zero value you use is greater that the maximum header size plus
2085 the size of your largest error page.
2086
2087 If you set this parameter none (the default), there will be
2088 no limit imposed.
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2089
2090 Configuration Format is:
2091 reply_body_max_size SIZE UNITS [acl ...]
2092 ie.
2093 reply_body_max_size 10 MB
2094
5b0f5383 2095DOC_END
2096
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CT
2097NAME: on_unsupported_protocol
2098TYPE: on_unsupported_protocol
2099LOC: Config.accessList.on_unsupported_protocol
2100DEFAULT: none
2101DEFAULT_DOC: Respond with an error message to unidentifiable traffic
2102DOC_START
2103 Determines Squid behavior when encountering strange requests at the
56d089f3
CT
2104 beginning of an accepted TCP connection or the beginning of a bumped
2105 CONNECT tunnel. Controlling Squid reaction to unexpected traffic is
2106 especially useful in interception environments where Squid is likely
2107 to see connections for unsupported protocols that Squid should either
2108 terminate or tunnel at TCP level.
9603207d 2109
3248e962 2110 on_unsupported_protocol <action> [!]acl ...
9603207d 2111
56d089f3 2112 The first matching action wins. Only fast ACLs are supported.
3248e962
CT
2113
2114 Supported actions are:
9603207d 2115
3248e962
CT
2116 tunnel: Establish a TCP connection with the intended server and
2117 blindly shovel TCP packets between the client and server.
2118
2119 respond: Respond with an error message, using the transfer protocol
2120 for the Squid port that received the request (e.g., HTTP
2121 for connections intercepted at the http_port). This is the
2122 default.
56d089f3
CT
2123
2124 Squid expects the following traffic patterns:
2125
2126 http_port: a plain HTTP request
2127 https_port: SSL/TLS handshake followed by an [encrypted] HTTP request
2128 ftp_port: a plain FTP command (no on_unsupported_protocol support yet!)
2129 CONNECT tunnel on http_port: same as https_port
2130 CONNECT tunnel on https_port: same as https_port
2131
9155253a 2132 Currently, this directive has effect on intercepted connections and
56d089f3
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2133 bumped tunnels only. Other cases are not supported because Squid
2134 cannot know the intended destination of other traffic.
3248e962
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2135
2136 For example:
2137 # define what Squid errors indicate receiving non-HTTP traffic:
2138 acl foreignProtocol squid_error ERR_PROTOCOL_UNKNOWN ERR_TOO_BIG
2139 # define what Squid errors indicate receiving nothing:
2140 acl serverTalksFirstProtocol squid_error ERR_REQUEST_START_TIMEOUT
2141 # tunnel everything that does not look like HTTP:
2142 on_unsupported_protocol tunnel foreignProtocol
2143 # tunnel if we think the client waits for the server to talk first:
2144 on_unsupported_protocol tunnel serverTalksFirstProtocol
2145 # in all other error cases, just send an HTTP "error page" response:
2146 on_unsupported_protocol respond all
2147
2148 See also: squid_error ACL
2149DOC_END
2150
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2151NAME: auth_schemes
2152TYPE: AuthSchemes
2153IFDEF: USE_AUTH
2154LOC: Auth::TheConfig.schemeAccess
2155DEFAULT: none
2156DEFAULT_DOC: use all auth_param schemes in their configuration order
2157DOC_START
2158 Use this directive to customize authentication schemes presence and
2159 order in Squid's Unauthorized and Authentication Required responses.
2160
2161 auth_schemes scheme1,scheme2,... [!]aclname ...
2162
2163 where schemeN is the name of one of the authentication schemes
2164 configured using auth_param directives. At least one scheme name is
2165 required. Multiple scheme names are separated by commas. Either
2166 avoid whitespace or quote the entire schemes list.
2167
2168 A special "ALL" scheme name expands to all auth_param-configured
2169 schemes in their configuration order. This directive cannot be used
2170 to configure Squid to offer no authentication schemes at all.
2171
2172 The first matching auth_schemes rule determines the schemes order
2173 for the current Authentication Required transaction. Note that the
2174 future response is not yet available during auth_schemes evaluation.
2175
2176 If this directive is not used or none of its rules match, then Squid
2177 responds with all configured authentication schemes in the order of
2178 auth_param directives in the configuration file.
2179
2180 This directive does not determine when authentication is used or
2181 how each authentication scheme authenticates clients.
2182
2183 The following example sends basic and negotiate authentication
2184 schemes, in that order, when requesting authentication of HTTP
2185 requests matching the isIE ACL (not shown) while sending all
2186 auth_param schemes in their configuration order to other clients:
2187
2188 auth_schemes basic,negotiate isIE
2189 auth_schemes ALL all # explicit default
2190
2191 This directive supports fast ACLs only.
2192
2193 See also: auth_param.
2194DOC_END
2195
5b0f5383 2196COMMENT_START
2197 NETWORK OPTIONS
2198 -----------------------------------------------------------------------------
2199COMMENT_END
2200
2201NAME: http_port ascii_port
65d448bc 2202TYPE: PortCfg
5b0f5383 2203DEFAULT: none
fa720bfb 2204LOC: HttpPortList
5b0f5383 2205DOC_START
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2206 Usage: port [mode] [options]
2207 hostname:port [mode] [options]
2208 1.2.3.4:port [mode] [options]
5b0f5383 2209
2210 The socket addresses where Squid will listen for HTTP client
2211 requests. You may specify multiple socket addresses.
2212 There are three forms: port alone, hostname with port, and
2213 IP address with port. If you specify a hostname or IP
2214 address, Squid binds the socket to that specific
c7b1dd5d 2215 address. Most likely, you do not need to bind to a specific
5b0f5383 2216 address, so you can use the port number alone.
2217
2218 If you are running Squid in accelerator mode, you
2219 probably want to listen on port 80 also, or instead.
2220
2221 The -a command line option may be used to specify additional
2222 port(s) where Squid listens for proxy request. Such ports will
2223 be plain proxy ports with no options.
2224
2225 You may specify multiple socket addresses on multiple lines.
2226
c7b1dd5d 2227 Modes:
5b0f5383 2228
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2229 intercept Support for IP-Layer NAT interception delivering
2230 traffic to this Squid port.
2231 NP: disables authentication on the port.
5b0f5383 2232
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2233 tproxy Support Linux TPROXY (or BSD divert-to) with spoofing
2234 of outgoing connections using the client IP address.
2235 NP: disables authentication on the port.
5b0f5383 2236
7f45065d 2237 accel Accelerator / reverse proxy mode
5b0f5383 2238
caf3666d 2239 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
c7b1dd5d 2240 establish secure connection with the client and with
caf3666d 2241 the server, decrypt HTTPS messages as they pass through
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2242 Squid, and treat them as unencrypted HTTP messages,
2243 becoming the man-in-the-middle.
2244
7a957a93 2245 The ssl_bump option is required to fully enable
caf3666d 2246 bumping of CONNECT requests.
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2247
2248 Omitting the mode flag causes default forward proxy mode to be used.
2249
2250
2251 Accelerator Mode Options:
2252
5b0f5383 2253 defaultsite=domainname
2254 What to use for the Host: header if it is not present
2255 in a request. Determines what site (not origin server)
2256 accelerators should consider the default.
5b0f5383 2257
cf673853 2258 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
5b0f5383 2259
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2260 protocol= Protocol to reconstruct accelerated and intercepted
2261 requests with. Defaults to HTTP/1.1 for http_port and
2262 HTTPS/1.1 for https_port.
2263 When an unsupported value is configured Squid will
2264 produce a FATAL error.
2265 Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
5b0f5383 2266
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2267 vport Virtual host port support. Using the http_port number
2268 instead of the port passed on Host: headers.
5b0f5383 2269
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2270 vport=NN Virtual host port support. Using the specified port
2271 number instead of the port passed on Host: headers.
5b0f5383 2272
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2273 act-as-origin
2274 Act as if this Squid is the origin server.
2275 This currently means generate new Date: and Expires:
2276 headers on HIT instead of adding Age:.
5b0f5383 2277
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2278 ignore-cc Ignore request Cache-Control headers.
2279
7f45065d 2280 WARNING: This option violates HTTP specifications if
432bc83c
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2281 used in non-accelerator setups.
2282
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2283 allow-direct Allow direct forwarding in accelerator mode. Normally
2284 accelerated requests are denied direct forwarding as if
2285 never_direct was used.
2286
2287 WARNING: this option opens accelerator mode to security
2288 vulnerabilities usually only affecting in interception
2289 mode. Make sure to protect forwarding with suitable
2290 http_access rules when using this.
2291
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2292
2293 SSL Bump Mode Options:
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2294 In addition to these options ssl-bump requires TLS/SSL options.
2295
2296 generate-host-certificates[=<on|off>]
2297 Dynamically create SSL server certificates for the
9603207d 2298 destination hosts of bumped CONNECT requests.When
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2299 enabled, the cert and key options are used to sign
2300 generated certificates. Otherwise generated
2301 certificate will be selfsigned.
9603207d 2302 If there is a CA certificate lifetime of the generated
859741ed 2303 certificate equals lifetime of the CA certificate. If
9603207d 2304 generated certificate is selfsigned lifetime is three
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2305 years.
2306 This option is enabled by default when ssl-bump is used.
2307 See the ssl-bump option above for more information.
9603207d 2308
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2309 dynamic_cert_mem_cache_size=SIZE
2310 Approximate total RAM size spent on cached generated
2311 certificates. If set to zero, caching is disabled. The
23bb0ebf 2312 default value is 4MB.
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2313
2314 TLS / SSL Options:
c7b1dd5d 2315
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2316 tls-cert= Path to file containing an X.509 certificate (PEM format)
2317 to be used in the TLS handshake ServerHello.
c7b1dd5d 2318
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2319 If this certificate is constrained by KeyUsage TLS
2320 feature it must allow HTTP server usage, along with
2321 any additional restrictions imposed by your choice
2322 of options= settings.
2323
2324 When OpenSSL is used this file may also contain a
2325 chain of intermediate CA certificates to send in the
2326 TLS handshake.
2327
2328 When GnuTLS is used this option (and any paired
2329 tls-key= option) may be repeated to load multiple
2330 certificates for different domains.
2331
2332 Also, when generate-host-certificates=on is configured
2333 the first tls-cert= option must be a CA certificate
2334 capable of signing the automatically generated
2335 certificates.
2336
2337 tls-key= Path to a file containing private key file (PEM format)
2338 for the previous tls-cert= option.
2339
2340 If tls-key= is not specified tls-cert= is assumed to
2341 reference a PEM file containing both the certificate
2342 and private key.
c7b1dd5d 2343
c7b1dd5d 2344 cipher= Colon separated list of supported ciphers.
bebdc6fb
AJ
2345 NOTE: some ciphers such as EDH ciphers depend on
2346 additional settings. If those settings are
2347 omitted the ciphers may be silently ignored
2348 by the OpenSSL library.
c7b1dd5d 2349
943c5f16 2350 options= Various SSL implementation options. The most important
c7b1dd5d 2351 being:
7905e7be 2352
3d96b0e8 2353 NO_SSLv3 Disallow the use of SSLv3
1f1f29e8 2354
3d96b0e8 2355 NO_TLSv1 Disallow the use of TLSv1.0
1f1f29e8 2356
3d96b0e8 2357 NO_TLSv1_1 Disallow the use of TLSv1.1
1f1f29e8 2358
3d96b0e8 2359 NO_TLSv1_2 Disallow the use of TLSv1.2
1f1f29e8 2360
7905e7be
AJ
2361 SINGLE_DH_USE
2362 Always create a new key when using
c7b1dd5d 2363 temporary/ephemeral DH key exchanges
1f1f29e8 2364
54fbe371
PM
2365 SINGLE_ECDH_USE
2366 Enable ephemeral ECDH key exchange.
2367 The adopted curve should be specified
2368 using the tls-dh option.
2369
36092741 2370 NO_TICKET
1f1f29e8
AJ
2371 Disable use of RFC5077 session tickets.
2372 Some servers may have problems
2373 understanding the TLS extension due
2374 to ambiguous specification in RFC4507.
2375
943c5f16
HN
2376 ALL Enable various bug workarounds
2377 suggested as "harmless" by OpenSSL
2378 Be warned that this reduces SSL/TLS
2379 strength to some attacks.
7905e7be
AJ
2380
2381 See the OpenSSL SSL_CTX_set_options documentation for a
2382 more complete list.
c7b1dd5d
AJ
2383
2384 clientca= File containing the list of CAs to use when
2385 requesting a client certificate.
2386
86a84cc0
AJ
2387 tls-cafile= PEM file containing CA certificates to use when verifying
2388 client certificates. If not configured clientca will be
2389 used. May be repeated to load multiple files.
c7b1dd5d
AJ
2390
2391 capath= Directory containing additional CA certificates
2392 and CRL lists to use when verifying client certificates.
86a84cc0 2393 Requires OpenSSL or LibreSSL.
c7b1dd5d
AJ
2394
2395 crlfile= File of additional CRL lists to use when verifying
2396 the client certificate, in addition to CRLs stored in
2397 the capath. Implies VERIFY_CRL flag below.
2398
54fbe371
PM
2399 tls-dh=[curve:]file
2400 File containing DH parameters for temporary/ephemeral DH key
2401 exchanges, optionally prefixed by a curve for ephemeral ECDH
2402 key exchanges.
2403 See OpenSSL documentation for details on how to create the
2404 DH parameter file. Supported curves for ECDH can be listed
2405 using the "openssl ecparam -list_curves" command.
2406 WARNING: EDH and EECDH ciphers will be silently disabled if
2407 this option is not set.
c7b1dd5d
AJ
2408
2409 sslflags= Various flags modifying the use of SSL:
2410 DELAYED_AUTH
2411 Don't request client certificates
2412 immediately, but wait until acl processing
2413 requires a certificate (not yet implemented).
983fab6e 2414 CONDITIONAL_AUTH
2415 Request a client certificate during the TLS
2416 handshake, but ignore certificate absence in
2417 the TLS client Hello. If the client does
2418 supply a certificate, it is validated.
c7b1dd5d
AJ
2419 NO_SESSION_REUSE
2420 Don't allow for session reuse. Each connection
2421 will result in a new SSL session.
2422 VERIFY_CRL
2423 Verify CRL lists when accepting client
2424 certificates.
2425 VERIFY_CRL_ALL
2426 Verify CRL lists for all certificates in the
2427 client certificate chain.
2428
435c72b0
AJ
2429 tls-default-ca[=off]
2430 Whether to use the system Trusted CAs. Default is OFF.
8b253b83 2431
b05d749d
AJ
2432 tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
2433
c7b1dd5d
AJ
2434 sslcontext= SSL session ID context identifier.
2435
c7b1dd5d
AJ
2436 Other Options:
2437
6b185b50 2438 connection-auth[=on|off]
9603207d 2439 use connection-auth=off to tell Squid to prevent
6b185b50 2440 forwarding Microsoft connection oriented authentication
d67acb4e
AJ
2441 (NTLM, Negotiate and Kerberos)
2442
5b0f5383 2443 disable-pmtu-discovery=
2444 Control Path-MTU discovery usage:
2445 off lets OS decide on what to do (default).
2446 transparent disable PMTU discovery when transparent
2447 support is enabled.
2448 always disable always PMTU discovery.
2449
2450 In many setups of transparently intercepting proxies
2451 Path-MTU discovery can not work on traffic towards the
2452 clients. This is the case when the intercepting device
2453 does not fully track connections and fails to forward
2454 ICMP must fragment messages to the cache server. If you
2455 have such setup and experience that certain clients
2456 sporadically hang or never complete requests set
2457 disable-pmtu-discovery option to 'transparent'.
2458
81b6e9a7 2459 name= Specifies a internal name for the port. Defaults to
2460 the port specification (port or addr:port)
2461
68924b6d 2462 tcpkeepalive[=idle,interval,timeout]
fb6c6dbe
AJ
2463 Enable TCP keepalive probes of idle connections.
2464 In seconds; idle is the initial time before TCP starts
2465 probing the connection, interval how often to probe, and
b2130d58 2466 timeout the time before giving up.
2467
d3d92daa 2468 require-proxy-header
151ba0d4 2469 Require PROXY protocol version 1 or 2 connections.
70d0ef18 2470 The proxy_protocol_access is required to permit
151ba0d4
AJ
2471 downstream proxies which can be trusted.
2472
7d17a6a6
EB
2473 worker-queues
2474 Ask TCP stack to maintain a dedicated listening queue
2475 for each worker accepting requests at this port.
2476 Requires TCP stack that supports the SO_REUSEPORT socket
2477 option.
2478
2479 SECURITY WARNING: Enabling worker-specific queues
2480 allows any process running as Squid's effective user to
2481 easily accept requests destined to this port.
2482
5b0f5383 2483 If you run Squid on a dual-homed machine with an internal
2484 and an external interface we recommend you to specify the
2485 internal address:port in http_port. This way Squid will only be
2486 visible on the internal address.
2487
47f0eaea 2488CONFIG_START
e0855596 2489
5b0f5383 2490# Squid normally listens to port 3128
2491http_port @DEFAULT_HTTP_PORT@
47f0eaea 2492CONFIG_END
5b0f5383 2493DOC_END
2494
2495NAME: https_port
339e4d7a 2496IFDEF: USE_GNUTLS||USE_OPENSSL
65d448bc 2497TYPE: PortCfg
5b0f5383 2498DEFAULT: none
339e4d7a 2499LOC: HttpPortList
5b0f5383 2500DOC_START
51e09c08 2501 Usage: [ip:]port [mode] tls-cert=certificate.pem [options]
5b0f5383 2502
859741ed
AJ
2503 The socket address where Squid will listen for client requests made
2504 over TLS or SSL connections. Commonly referred to as HTTPS.
5b0f5383 2505
859741ed 2506 This is most useful for situations where you are running squid in
51e09c08
AJ
2507 accelerator mode and you want to do the TLS work at the accelerator
2508 level.
5b0f5383 2509
2510 You may specify multiple socket addresses on multiple lines,
9155253a 2511 each with their own certificate and/or options.
5b0f5383 2512
51e09c08 2513 The tls-cert= option is mandatory on HTTPS ports.
379e8c1c 2514
9155253a 2515 See http_port for a list of modes and options.
5b0f5383 2516DOC_END
2517
434a79b0
DK
2518NAME: ftp_port
2519TYPE: PortCfg
2520DEFAULT: none
8ea0d847 2521LOC: FtpPortList
434a79b0 2522DOC_START
8a2f40dd
AR
2523 Enables Native FTP proxy by specifying the socket address where Squid
2524 listens for FTP client requests. See http_port directive for various
2525 ways to specify the listening address and mode.
2526
2527 Usage: ftp_port address [mode] [options]
2528
2529 WARNING: This is a new, experimental, complex feature that has seen
2530 limited production exposure. Some Squid modules (e.g., caching) do not
2531 currently work with native FTP proxying, and many features have not
2532 even been tested for compatibility. Test well before deploying!
2533
2534 Native FTP proxying differs substantially from proxying HTTP requests
2535 with ftp:// URIs because Squid works as an FTP server and receives
2536 actual FTP commands (rather than HTTP requests with FTP URLs).
2537
2538 Native FTP commands accepted at ftp_port are internally converted or
2539 wrapped into HTTP-like messages. The same happens to Native FTP
2540 responses received from FTP origin servers. Those HTTP-like messages
2541 are shoveled through regular access control and adaptation layers
2542 between the FTP client and the FTP origin server. This allows Squid to
2543 examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
2544 mechanisms when shoveling wrapped FTP messages. For example,
2545 http_access and adaptation_access directives are used.
2546
2547 Modes:
2548
3cc0f4e7 2549 intercept Same as http_port intercept. The FTP origin address is
8a2f40dd
AR
2550 determined based on the intended destination of the
2551 intercepted connection.
2552
3cc0f4e7
AR
2553 tproxy Support Linux TPROXY for spoofing outgoing
2554 connections using the client IP address.
2555 NP: disables authentication and maybe IPv6 on the port.
2556
8a2f40dd
AR
2557 By default (i.e., without an explicit mode option), Squid extracts the
2558 FTP origin address from the login@origin parameter of the FTP USER
2559 command. Many popular FTP clients support such native FTP proxying.
2560
2561 Options:
2562
3cc0f4e7
AR
2563 name=token Specifies an internal name for the port. Defaults to
2564 the port address. Usable with myportname ACL.
2565
aea65fec 2566 ftp-track-dirs
8a2f40dd
AR
2567 Enables tracking of FTP directories by injecting extra
2568 PWD commands and adjusting Request-URI (in wrapping
2569 HTTP requests) to reflect the current FTP server
aea65fec 2570 directory. Tracking is disabled by default.
8a2f40dd 2571
3cc0f4e7
AR
2572 protocol=FTP Protocol to reconstruct accelerated and intercepted
2573 requests with. Defaults to FTP. No other accepted
2574 values have been tested with. An unsupported value
2575 results in a FATAL error. Accepted values are FTP,
2576 HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
2577
8a2f40dd
AR
2578 Other http_port modes and options that are not specific to HTTP and
2579 HTTPS may also work.
2580DOC_END
434a79b0 2581
41bd17a4 2582NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2583TYPE: acl_tos
5473c134 2584DEFAULT: none
425de4c8 2585LOC: Ip::Qos::TheConfig.tosToServer
5473c134 2586DOC_START
425de4c8
AJ
2587 Allows you to select a TOS/Diffserv value for packets outgoing
2588 on the server side, based on an ACL.
5473c134 2589
41bd17a4 2590 tcp_outgoing_tos ds-field [!]aclname ...
cccac0a2 2591
41bd17a4 2592 Example where normal_service_net uses the TOS value 0x00
7def7206 2593 and good_service_net uses 0x20
cccac0a2 2594
864a62b5
AJ
2595 acl normal_service_net src 10.0.0.0/24
2596 acl good_service_net src 10.0.1.0/24
2c73de90 2597 tcp_outgoing_tos 0x00 normal_service_net
41bd17a4 2598 tcp_outgoing_tos 0x20 good_service_net
fa38076e 2599
41bd17a4 2600 TOS/DSCP values really only have local significance - so you should
575cb927
AJ
2601 know what you're specifying. For more information, see RFC2474,
2602 RFC2475, and RFC3260.
cccac0a2 2603
41bd17a4 2604 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
5f53baab
SM
2605 "default" to use whatever default your host has.
2606 Note that only multiples of 4 are usable as the two rightmost bits have
2607 been redefined for use by ECN (RFC 3168 section 23.1).
2608 The squid parser will enforce this by masking away the ECN bits.
cccac0a2 2609
41bd17a4 2610 Processing proceeds in the order specified, and stops at first fully
2611 matching line.
c6f168c1
CT
2612
2613 Only fast ACLs are supported.
cccac0a2 2614DOC_END
2615
41bd17a4 2616NAME: clientside_tos
2617TYPE: acl_tos
cccac0a2 2618DEFAULT: none
425de4c8
AJ
2619LOC: Ip::Qos::TheConfig.tosToClient
2620DOC_START
5f53baab 2621 Allows you to select a TOS/DSCP value for packets being transmitted
425de4c8
AJ
2622 on the client-side, based on an ACL.
2623
2624 clientside_tos ds-field [!]aclname ...
2625
2626 Example where normal_service_net uses the TOS value 0x00
2627 and good_service_net uses 0x20
2628
2629 acl normal_service_net src 10.0.0.0/24
2630 acl good_service_net src 10.0.1.0/24
2631 clientside_tos 0x00 normal_service_net
2632 clientside_tos 0x20 good_service_net
2633
2634 Note: This feature is incompatible with qos_flows. Any TOS values set here
2635 will be overwritten by TOS values in qos_flows.
5f53baab
SM
2636
2637 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2638 "default" to use whatever default your host has.
2639 Note that only multiples of 4 are usable as the two rightmost bits have
2640 been redefined for use by ECN (RFC 3168 section 23.1).
2641 The squid parser will enforce this by masking away the ECN bits.
2642
83a846a3
AR
2643 This clause only supports fast acl types.
2644 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
425de4c8
AJ
2645DOC_END
2646
2647NAME: tcp_outgoing_mark
2648TYPE: acl_nfmark
11e8cfe3 2649IFDEF: SO_MARK&&USE_LIBCAP
425de4c8
AJ
2650DEFAULT: none
2651LOC: Ip::Qos::TheConfig.nfmarkToServer
2652DOC_START
2653 Allows you to apply a Netfilter mark value to outgoing packets
2654 on the server side, based on an ACL.
2655
2656 tcp_outgoing_mark mark-value [!]aclname ...
2657
2658 Example where normal_service_net uses the mark value 0x00
2659 and good_service_net uses 0x20
2660
2661 acl normal_service_net src 10.0.0.0/24
2662 acl good_service_net src 10.0.1.0/24
2663 tcp_outgoing_mark 0x00 normal_service_net
2664 tcp_outgoing_mark 0x20 good_service_net
c6f168c1
CT
2665
2666 Only fast ACLs are supported.
425de4c8
AJ
2667DOC_END
2668
244da4ad 2669NAME: mark_client_packet clientside_mark
425de4c8 2670TYPE: acl_nfmark
11e8cfe3 2671IFDEF: SO_MARK&&USE_LIBCAP
425de4c8
AJ
2672DEFAULT: none
2673LOC: Ip::Qos::TheConfig.nfmarkToClient
cccac0a2 2674DOC_START
244da4ad 2675 Allows you to apply a Netfilter MARK value to packets being transmitted
425de4c8
AJ
2676 on the client-side, based on an ACL.
2677
244da4ad 2678 mark_client_packet mark-value [!]aclname ...
425de4c8 2679
244da4ad 2680 Example where normal_service_net uses the MARK value 0x00
425de4c8
AJ
2681 and good_service_net uses 0x20
2682
2683 acl normal_service_net src 10.0.0.0/24
2684 acl good_service_net src 10.0.1.0/24
244da4ad
AG
2685 mark_client_packet 0x00 normal_service_net
2686 mark_client_packet 0x20 good_service_net
425de4c8
AJ
2687
2688 Note: This feature is incompatible with qos_flows. Any mark values set here
2689 will be overwritten by mark values in qos_flows.
83a846a3
AR
2690
2691 This clause only supports fast acl types.
2692 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2693DOC_END
cccac0a2 2694
244da4ad
AG
2695NAME: mark_client_connection
2696TYPE: acl_nfmark
2697IFDEF: SO_MARK&&USE_LIBCAP
2698DEFAULT: none
2699LOC: Ip::Qos::TheConfig.nfConnmarkToClient
2700DOC_START
2701 Allows you to apply a Netfilter CONNMARK value to a connection
2702 on the client-side, based on an ACL.
2703
2704 mark_client_connection mark-value[/mask] [!]aclname ...
2705
2706 The mark-value and mask are unsigned integers (hex, octal, or decimal).
2707 The mask may be used to preserve marking previously set by other agents
2708 (e.g., iptables).
2709
2710 A matching rule replaces the CONNMARK value. If a mask is also
2711 specified, then the masked bits of the original value are zeroed, and
2712 the configured mark-value is ORed with that adjusted value.
2713 For example, applying a mark-value 0xAB/0xF to 0x5F CONNMARK, results
2714 in a 0xFB marking (rather than a 0xAB or 0x5B).
2715
2716 This directive semantics is similar to iptables --set-mark rather than
2717 --set-xmark functionality.
2718
2719 The directive does not interfere with qos_flows (which uses packet MARKs,
2720 not CONNMARKs).
2721
2722 Example where squid marks intercepted FTP connections:
2723
2724 acl proto_ftp proto FTP
2725 mark_client_connection 0x200/0xff00 proto_ftp
2726
2727 This clause only supports fast acl types.
2728 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2729DOC_END
2730
575cb927
AJ
2731NAME: qos_flows
2732TYPE: QosConfig
425de4c8 2733IFDEF: USE_QOS_TOS
575cb927 2734DEFAULT: none
b7ac5457 2735LOC: Ip::Qos::TheConfig
7172612f 2736DOC_START
575cb927 2737 Allows you to select a TOS/DSCP value to mark outgoing
196a7776
AB
2738 connections to the client, based on where the reply was sourced.
2739 For platforms using netfilter, allows you to set a netfilter mark
425de4c8 2740 value instead of, or in addition to, a TOS value.
7172612f 2741
196a7776
AB
2742 By default this functionality is disabled. To enable it with the default
2743 settings simply use "qos_flows mark" or "qos_flows tos". Default
2744 settings will result in the netfilter mark or TOS value being copied
2745 from the upstream connection to the client. Note that it is the connection
2746 CONNMARK value not the packet MARK value that is copied.
2747
2748 It is not currently possible to copy the mark or TOS value from the
2749 client to the upstream connection request.
2750
575cb927
AJ
2751 TOS values really only have local significance - so you should
2752 know what you're specifying. For more information, see RFC2474,
2753 RFC2475, and RFC3260.
7172612f 2754
5f53baab
SM
2755 The TOS/DSCP byte must be exactly that - a octet value 0 - 255.
2756 Note that only multiples of 4 are usable as the two rightmost bits have
2757 been redefined for use by ECN (RFC 3168 section 23.1).
2758 The squid parser will enforce this by masking away the ECN bits.
425de4c8
AJ
2759
2760 Mark values can be any unsigned 32-bit integer value.
7172612f 2761
425de4c8
AJ
2762 This setting is configured by setting the following values:
2763
2764 tos|mark Whether to set TOS or netfilter mark values
575cb927
AJ
2765
2766 local-hit=0xFF Value to mark local cache hits.
2767
2768 sibling-hit=0xFF Value to mark hits from sibling peers.
2769
2770 parent-hit=0xFF Value to mark hits from parent peers.
2771
a29d2a95
AB
2772 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2773 over the preserve-miss feature (see below), unless
2774 mask is specified, in which case only the bits
2775 specified in the mask are written.
575cb927 2776
425de4c8
AJ
2777 The TOS variant of the following features are only possible on Linux
2778 and require your kernel to be patched with the TOS preserving ZPH
2779 patch, available from http://zph.bratcheda.org
2780 No patch is needed to preserve the netfilter mark, which will work
2781 with all variants of netfilter.
575cb927 2782
575cb927 2783 disable-preserve-miss
425de4c8
AJ
2784 This option disables the preservation of the TOS or netfilter
2785 mark. By default, the existing TOS or netfilter mark value of
2786 the response coming from the remote server will be retained
2787 and masked with miss-mark.
2788 NOTE: in the case of a netfilter mark, the mark must be set on
2789 the connection (using the CONNMARK target) not on the packet
2790 (MARK target).
575cb927
AJ
2791
2792 miss-mask=0xFF
425de4c8
AJ
2793 Allows you to mask certain bits in the TOS or mark value
2794 received from the remote server, before copying the value to
2795 the TOS sent towards clients.
2796 Default for tos: 0xFF (TOS from server is not changed).
2797 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2798
2799 All of these features require the --enable-zph-qos compilation flag
2800 (enabled by default). Netfilter marking also requires the
2801 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2802 libcap 2.09+ (--with-libcap).
7172612f 2803
7172612f
AJ
2804DOC_END
2805
41bd17a4 2806NAME: tcp_outgoing_address
2807TYPE: acl_address
2808DEFAULT: none
638402dd 2809DEFAULT_DOC: Address selection is performed by the operating system.
41bd17a4 2810LOC: Config.accessList.outgoing_address
2811DOC_START
2812 Allows you to map requests to different outgoing IP addresses
2813 based on the username or source address of the user making
2814 the request.
7f7db318 2815
41bd17a4 2816 tcp_outgoing_address ipaddr [[!]aclname] ...
c33aa074 2817
2dd51400
AJ
2818 For example;
2819 Forwarding clients with dedicated IPs for certain subnets.
9197cd13 2820
2dd51400
AJ
2821 acl normal_service_net src 10.0.0.0/24
2822 acl good_service_net src 10.0.2.0/24
2823
2824 tcp_outgoing_address 2001:db8::c001 good_service_net
2825 tcp_outgoing_address 10.1.0.2 good_service_net
2826
2827 tcp_outgoing_address 2001:db8::beef normal_service_net
2828 tcp_outgoing_address 10.1.0.1 normal_service_net
2829
2830 tcp_outgoing_address 2001:db8::1
2831 tcp_outgoing_address 10.1.0.3
9197cd13 2832
41bd17a4 2833 Processing proceeds in the order specified, and stops at first fully
2834 matching line.
cccac0a2 2835
2dd51400
AJ
2836 Squid will add an implicit IP version test to each line.
2837 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2838 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2839
2840
2841 NOTE: The use of this directive using client dependent ACLs is
41bd17a4 2842 incompatible with the use of server side persistent connections. To
2843 ensure correct results it is best to set server_persistent_connections
2844 to off when using this directive in such configurations.
cc192b50 2845
2dd51400 2846 NOTE: The use of this directive to set a local IP on outgoing TCP links
4ed968be 2847 is incompatible with using TPROXY to set client IP out outbound TCP links.
2dd51400
AJ
2848 When needing to contact peers use the no-tproxy cache_peer option and the
2849 client_dst_passthru directive re-enable normal forwarding such as this.
cc192b50 2850
83a846a3
AR
2851 This clause only supports fast acl types.
2852 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 2853DOC_END
6db78a1a 2854
90529125
AJ
2855NAME: host_verify_strict
2856TYPE: onoff
2857DEFAULT: off
2858LOC: Config.onoff.hostStrictVerify
2859DOC_START
d8821934
AR
2860 Regardless of this option setting, when dealing with intercepted
2861 traffic, Squid always verifies that the destination IP address matches
2962f8b8 2862 the Host header domain or IP (called 'authority form URL').
9603207d 2863
d8821934
AR
2864 This enforcement is performed to satisfy a MUST-level requirement in
2865 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2866 authority of the origin server or gateway given by the original URL".
9603207d 2867
2962f8b8
AJ
2868 When set to ON:
2869 Squid always responds with an HTTP 409 (Conflict) error
2870 page and logs a security warning if there is no match.
9603207d 2871
2962f8b8
AJ
2872 Squid verifies that the destination IP address matches
2873 the Host header for forward-proxy and reverse-proxy traffic
2874 as well. For those traffic types, Squid also enables the
2875 following checks, comparing the corresponding Host header
2876 and Request-URI components:
9603207d 2877
2962f8b8
AJ
2878 * The host names (domain or IP) must be identical,
2879 but valueless or missing Host header disables all checks.
2880 For the two host names to match, both must be either IP
2881 or FQDN.
9603207d 2882
2962f8b8
AJ
2883 * Port numbers must be identical, but if a port is missing
2884 the scheme-default port is assumed.
9603207d 2885
2886
2962f8b8
AJ
2887 When set to OFF (the default):
2888 Squid allows suspicious requests to continue but logs a
2889 security warning and blocks caching of the response.
9603207d 2890
2962f8b8 2891 * Forward-proxy traffic is not checked at all.
9603207d 2892
2962f8b8 2893 * Reverse-proxy traffic is not checked at all.
9603207d 2894
2962f8b8 2895 * Intercepted traffic which passes verification is handled
32c32865 2896 according to client_dst_passthru.
9603207d 2897
7177edfb
AJ
2898 * Intercepted requests which fail verification are sent
2899 to the client original destination instead of DIRECT.
2900 This overrides 'client_dst_passthru off'.
9603207d 2901
2962f8b8
AJ
2902 For now suspicious intercepted CONNECT requests are always
2903 responded to with an HTTP 409 (Conflict) error page.
9603207d 2904
2905
7177edfb 2906 SECURITY NOTE:
9603207d 2907
bfe4e2fe
AJ
2908 As described in CVE-2009-0801 when the Host: header alone is used
2909 to determine the destination of a request it becomes trivial for
2910 malicious scripts on remote websites to bypass browser same-origin
2911 security policy and sandboxing protections.
9603207d 2912
bfe4e2fe
AJ
2913 The cause of this is that such applets are allowed to perform their
2914 own HTTP stack, in which case the same-origin policy of the browser
2915 sandbox only verifies that the applet tries to contact the same IP
2916 as from where it was loaded at the IP level. The Host: header may
2917 be different from the connected IP and approved origin.
9603207d 2918
7177edfb 2919DOC_END
6b185b50 2920
7177edfb
AJ
2921NAME: client_dst_passthru
2922TYPE: onoff
2923DEFAULT: on
2924LOC: Config.onoff.client_dst_passthru
2925DOC_START
2926 With NAT or TPROXY intercepted traffic Squid may pass the request
2927 directly to the original client destination IP or seek a faster
2928 source using the HTTP Host header.
9603207d 2929
7177edfb
AJ
2930 Using Host to locate alternative servers can provide faster
2931 connectivity with a range of failure recovery options.
2932 But can also lead to connectivity trouble when the client and
2933 server are attempting stateful interactions unaware of the proxy.
9603207d 2934
7177edfb
AJ
2935 This option (on by default) prevents alternative DNS entries being
2936 located to send intercepted traffic DIRECT to an origin server.
2937 The clients original destination IP and port will be used instead.
9603207d 2938
7177edfb
AJ
2939 Regardless of this option setting, when dealing with intercepted
2940 traffic Squid will verify the Host: header and any traffic which
2941 fails Host verification will be treated as if this option were ON.
9603207d 2942
7177edfb 2943 see host_verify_strict for details on the verification process.
cccac0a2 2944DOC_END
2945
195f8adb
AJ
2946COMMENT_START
2947 TLS OPTIONS
2948 -----------------------------------------------------------------------------
2949COMMENT_END
2950
2951NAME: tls_outgoing_options
2952IFDEF: USE_GNUTLS||USE_OPENSSL
2953TYPE: securePeerOptions
2fbb02b1 2954DEFAULT: min-version=1.0
7e62a74f 2955LOC: Security::ProxyOutgoingConfig
195f8adb
AJ
2956DOC_START
2957 disable Do not support https:// URLs.
9603207d 2958
195f8adb 2959 cert=/path/to/client/certificate
51e09c08 2960 A client X.509 certificate to use when connecting.
9603207d 2961
195f8adb 2962 key=/path/to/client/private_key
51e09c08
AJ
2963 The private key corresponding to the cert= above.
2964
2965 If key= is not specified cert= is assumed to
2966 reference a PEM file containing both the certificate
2967 and private key.
9603207d 2968
195f8adb 2969 cipher=... The list of valid TLS ciphers to use.
1cc44095
AJ
2970
2971 min-version=1.N
2fbb02b1
AJ
2972 The minimum TLS protocol version to permit.
2973 To control SSLv3 use the options= parameter.
d39e23a0 2974 Supported Values: 1.0 (default), 1.1, 1.2, 1.3
1cc44095 2975
3f5b28fe 2976 options=... Specify various TLS/SSL implementation options.
195f8adb 2977
3f5b28fe 2978 OpenSSL options most important are:
7905e7be 2979
3f5b28fe 2980 NO_SSLv3 Disallow the use of SSLv3
7905e7be 2981
195f8adb
AJ
2982 SINGLE_DH_USE
2983 Always create a new key when using
2984 temporary/ephemeral DH key exchanges
7905e7be 2985
ce0adf1a 2986 NO_TICKET
7905e7be
AJ
2987 Disable use of RFC5077 session tickets.
2988 Some servers may have problems
2989 understanding the TLS extension due
2990 to ambiguous specification in RFC4507.
2991
195f8adb
AJ
2992 ALL Enable various bug workarounds
2993 suggested as "harmless" by OpenSSL
7905e7be 2994 Be warned that this reduces SSL/TLS
195f8adb
AJ
2995 strength to some attacks.
2996
3f5b28fe
AJ
2997 See the OpenSSL SSL_CTX_set_options documentation
2998 for a more complete list.
2999
3000 GnuTLS options most important are:
3001
3002 %NO_TICKETS
3003 Disable use of RFC5077 session tickets.
3004 Some servers may have problems
3005 understanding the TLS extension due
3006 to ambiguous specification in RFC4507.
3007
3008 See the GnuTLS Priority Strings documentation
3009 for a more complete list.
3010 http://www.gnutls.org/manual/gnutls.html#Priority-Strings
3011
9603207d 3012
86a84cc0
AJ
3013 cafile= PEM file containing CA certificates to use when verifying
3014 the peer certificate. May be repeated to load multiple files.
3015
3016 capath= A directory containing additional CA certificates to
195f8adb 3017 use when verifying the peer certificate.
86a84cc0 3018 Requires OpenSSL or LibreSSL.
9603207d 3019
195f8adb
AJ
3020 crlfile=... A certificate revocation list file to use when
3021 verifying the peer certificate.
9603207d 3022
195f8adb 3023 flags=... Specify various flags modifying the TLS implementation:
9603207d 3024
195f8adb
AJ
3025 DONT_VERIFY_PEER
3026 Accept certificates even if they fail to
3027 verify.
195f8adb
AJ
3028 DONT_VERIFY_DOMAIN
3029 Don't verify the peer certificate
3030 matches the server name
9603207d 3031
435c72b0
AJ
3032 default-ca[=off]
3033 Whether to use the system Trusted CAs. Default is ON.
9603207d 3034
195f8adb
AJ
3035 domain= The peer name as advertised in its certificate.
3036 Used for verifying the correctness of the received peer
3037 certificate. If not specified the peer hostname will be
3038 used.
3039DOC_END
3040
41bd17a4 3041COMMENT_START
3042 SSL OPTIONS
3043 -----------------------------------------------------------------------------
3044COMMENT_END
3045
3046NAME: ssl_unclean_shutdown
cb4f4424 3047IFDEF: USE_OPENSSL
cccac0a2 3048TYPE: onoff
3049DEFAULT: off
41bd17a4 3050LOC: Config.SSL.unclean_shutdown
cccac0a2 3051DOC_START
41bd17a4 3052 Some browsers (especially MSIE) bugs out on SSL shutdown
3053 messages.
cccac0a2 3054DOC_END
3055
41bd17a4 3056NAME: ssl_engine
cb4f4424 3057IFDEF: USE_OPENSSL
cccac0a2 3058TYPE: string
41bd17a4 3059LOC: Config.SSL.ssl_engine
3060DEFAULT: none
cccac0a2 3061DOC_START
41bd17a4 3062 The OpenSSL engine to use. You will need to set this if you
3063 would like to use hardware SSL acceleration for example.
742236c7
AJ
3064
3065 Not supported in builds with OpenSSL v3 or newer.
cccac0a2 3066DOC_END
3067
10a69fc0 3068NAME: sslproxy_session_ttl
cb4f4424 3069IFDEF: USE_OPENSSL
10a69fc0
CT
3070DEFAULT: 300
3071LOC: Config.SSL.session_ttl
3072TYPE: int
3073DOC_START
3074 Sets the timeout value for SSL sessions
3075DOC_END
3076
3077NAME: sslproxy_session_cache_size
cb4f4424 3078IFDEF: USE_OPENSSL
10a69fc0
CT
3079DEFAULT: 2 MB
3080LOC: Config.SSL.sessionCacheSize
3081TYPE: b_size_t
3082DOC_START
3083 Sets the cache size to use for ssl session
3084DOC_END
3085
866be11c
CT
3086NAME: sslproxy_foreign_intermediate_certs
3087IFDEF: USE_OPENSSL
3088DEFAULT: none
3089LOC: Config.ssl_client.foreignIntermediateCertsPath
3090TYPE: string
3091DOC_START
3092 Many origin servers fail to send their full server certificate
3093 chain for verification, assuming the client already has or can
3094 easily locate any missing intermediate certificates.
3095
3096 Squid uses the certificates from the specified file to fill in
3097 these missing chains when trying to validate origin server
3098 certificate chains.
3099
3100 The file is expected to contain zero or more PEM-encoded
3101 intermediate certificates. These certificates are not treated
3102 as trusted root certificates, and any self-signed certificate in
3103 this file will be ignored.
866be11c
CT
3104DOC_END
3105
3c26b00a
CT
3106NAME: sslproxy_cert_sign_hash
3107IFDEF: USE_OPENSSL
3108DEFAULT: none
3109LOC: Config.SSL.certSignHash
3110TYPE: string
3111DOC_START
3112 Sets the hashing algorithm to use when signing generated certificates.
3113 Valid algorithm names depend on the OpenSSL library used. The following
3114 names are usually available: sha1, sha256, sha512, and md5. Please see
3115 your OpenSSL library manual for the available hashes. By default, Squids
3116 that support this option use sha256 hashes.
3117
3118 Squid does not forcefully purge cached certificates that were generated
3119 with an algorithm other than the currently configured one. They remain
3120 in the cache, subject to the regular cache eviction policy, and become
3121 useful if the algorithm changes again.
3122DOC_END
3123
4c9da963 3124NAME: ssl_bump
cb4f4424 3125IFDEF: USE_OPENSSL
caf3666d 3126TYPE: sslproxy_ssl_bump
4c9da963 3127LOC: Config.accessList.ssl_bump
8f165829 3128DEFAULT_DOC: Become a TCP tunnel without decrypting proxied traffic.
4c9da963 3129DEFAULT: none
3130DOC_START
caf3666d
AR
3131 This option is consulted when a CONNECT request is received on
3132 an http_port (or a new connection is intercepted at an
3133 https_port), provided that port was configured with an ssl-bump
3134 flag. The subsequent data on the connection is either treated as
3135 HTTPS and decrypted OR tunneled at TCP level without decryption,
8f165829
AR
3136 depending on the first matching bumping "action".
3137
3138 ssl_bump <action> [!]acl ...
caf3666d 3139
8f165829 3140 The following bumping actions are currently supported:
caf3666d 3141
5d65362c 3142 splice
8f165829
AR
3143 Become a TCP tunnel without decrypting proxied traffic.
3144 This is the default action.
5d65362c
CT
3145
3146 bump
6e0516b3
CT
3147 When used on step SslBump1, establishes a secure connection
3148 with the client first, then connect to the server.
3149 When used on step SslBump2 or SslBump3, establishes a secure
3150 connection with the server and, using a mimicked server
3151 certificate, with the client.
caf3666d 3152
5d65362c 3153 peek
1110989a 3154 Receive client (step SslBump1) or server (step SslBump2)
8f165829
AR
3155 certificate while preserving the possibility of splicing the
3156 connection. Peeking at the server certificate (during step 2)
3157 usually precludes bumping of the connection at step 3.
caf3666d 3158
5d65362c 3159 stare
1110989a 3160 Receive client (step SslBump1) or server (step SslBump2)
8f165829
AR
3161 certificate while preserving the possibility of bumping the
3162 connection. Staring at the server certificate (during step 2)
3163 usually precludes splicing of the connection at step 3.
5d65362c
CT
3164
3165 terminate
3166 Close client and server connections.
3167
1110989a 3168 Backward compatibility actions available at step SslBump1:
caf3666d
AR
3169
3170 client-first
8f165829
AR
3171 Bump the connection. Establish a secure connection with the
3172 client first, then connect to the server. This old mode does
3173 not allow Squid to mimic server SSL certificate and does not
3174 work with intercepted SSL connections.
caf3666d
AR
3175
3176 server-first
8f165829
AR
3177 Bump the connection. Establish a secure connection with the
3178 server first, then establish a secure connection with the
3179 client, using a mimicked server certificate. Works with both
3180 CONNECT requests and intercepted SSL connections, but does
3181 not allow to make decisions based on SSL handshake info.
caf3666d 3182
8f165829 3183 peek-and-splice
9603207d 3184 Decide whether to bump or splice the connection based on
d620ae0e 3185 client-to-squid and server-to-squid SSL hello messages.
8f165829 3186 XXX: Remove.
caf3666d 3187
caf3666d 3188 none
8f165829 3189 Same as the "splice" action.
caf3666d 3190
8f165829
AR
3191 All ssl_bump rules are evaluated at each of the supported bumping
3192 steps. Rules with actions that are impossible at the current step are
3193 ignored. The first matching ssl_bump action wins and is applied at the
3194 end of the current step. If no rules match, the splice action is used.
652fcffd 3195 See the at_step ACL for a list of the supported SslBump steps.
4c9da963 3196
e0c0d54c 3197 This clause supports both fast and slow acl types.
b3567eb5 3198 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
e0855596 3199
652fcffd 3200 See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
caf3666d 3201
e0855596 3202
f3fece95 3203 # Example: Bump all TLS connections except those originating from
638402dd 3204 # localhost or those going to example.com.
e0855596 3205
f3fece95 3206 acl broken_sites ssl::server_name .example.com
8f165829
AR
3207 ssl_bump splice localhost
3208 ssl_bump splice broken_sites
3209 ssl_bump bump all
4c9da963 3210DOC_END
3211
4c9da963 3212NAME: sslproxy_cert_error
cb4f4424 3213IFDEF: USE_OPENSSL
4c9da963 3214DEFAULT: none
638402dd 3215DEFAULT_DOC: Server certificate errors terminate the transaction.
4c9da963 3216LOC: Config.ssl_client.cert_error
3217TYPE: acl_access
3218DOC_START
3219 Use this ACL to bypass server certificate validation errors.
3220
3221 For example, the following lines will bypass all validation errors
3b8f558c 3222 when talking to servers for example.com. All other
4c9da963 3223 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
3224
a87bfd3b
AR
3225 acl BrokenButTrustedServers dstdomain example.com
3226 sslproxy_cert_error allow BrokenButTrustedServers
4c9da963 3227 sslproxy_cert_error deny all
3228
b3567eb5
FC
3229 This clause only supports fast acl types.
3230 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3231 Using slow acl types may result in server crashes
4c9da963 3232
3233 Without this option, all server certificate validation errors
638402dd 3234 terminate the transaction to protect Squid and the client.
4c9da963 3235
0ad3ff51
CT
3236 SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
3237 but should not happen unless your OpenSSL library is buggy.
3238
638402dd
AJ
3239 SECURITY WARNING:
3240 Bypassing validation errors is dangerous because an
3241 error usually implies that the server cannot be trusted
3242 and the connection may be insecure.
4c9da963 3243
638402dd 3244 See also: sslproxy_flags and DONT_VERIFY_PEER.
4c9da963 3245DOC_END
3246
aebe6888 3247NAME: sslproxy_cert_sign
cb4f4424 3248IFDEF: USE_OPENSSL
aebe6888 3249DEFAULT: none
10d914f6
CT
3250POSTSCRIPTUM: signUntrusted ssl::certUntrusted
3251POSTSCRIPTUM: signSelf ssl::certSelfSigned
3252POSTSCRIPTUM: signTrusted all
aebe6888
CT
3253TYPE: sslproxy_cert_sign
3254LOC: Config.ssl_client.cert_sign
3255DOC_START
3256
69742b76 3257 sslproxy_cert_sign <signing algorithm> acl ...
aebe6888 3258
69742b76 3259 The following certificate signing algorithms are supported:
638402dd 3260
aebe6888 3261 signTrusted
69742b76
AR
3262 Sign using the configured CA certificate which is usually
3263 placed in and trusted by end-user browsers. This is the
3264 default for trusted origin server certificates.
638402dd 3265
aebe6888 3266 signUntrusted
69742b76
AR
3267 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
3268 This is the default for untrusted origin server certificates
3269 that are not self-signed (see ssl::certUntrusted).
638402dd 3270
aebe6888 3271 signSelf
69742b76 3272 Sign using a self-signed certificate with the right CN to
aebe6888 3273 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
69742b76
AR
3274 browser. This is the default for self-signed origin server
3275 certificates (see ssl::certSelfSigned).
aebe6888 3276
cf1c09f6
CT
3277 This clause only supports fast acl types.
3278
69742b76
AR
3279 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
3280 signing algorithm to generate the certificate and ignores all
3281 subsequent sslproxy_cert_sign options (the first match wins). If no
3282 acl(s) match, the default signing algorithm is determined by errors
3283 detected when obtaining and validating the origin server certificate.
cf1c09f6 3284
4b0d23b7
CT
3285 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
3286 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
3287 CONNECT request that carries a domain name. In all other cases (CONNECT
3288 to an IP address or an intercepted SSL connection), Squid cannot detect
3289 the domain mismatch at certificate generation time when
3290 bump-server-first is used.
aebe6888
CT
3291DOC_END
3292
638402dd 3293NAME: sslproxy_cert_adapt
cb4f4424 3294IFDEF: USE_OPENSSL
fb2178bb
CT
3295DEFAULT: none
3296TYPE: sslproxy_cert_adapt
3297LOC: Config.ssl_client.cert_adapt
3298DOC_START
9603207d 3299
fb2178bb
CT
3300 sslproxy_cert_adapt <adaptation algorithm> acl ...
3301
69742b76 3302 The following certificate adaptation algorithms are supported:
638402dd 3303
fb2178bb 3304 setValidAfter
69742b76
AR
3305 Sets the "Not After" property to the "Not After" property of
3306 the CA certificate used to sign generated certificates.
638402dd 3307
fb2178bb 3308 setValidBefore
69742b76
AR
3309 Sets the "Not Before" property to the "Not Before" property of
3310 the CA certificate used to sign generated certificates.
638402dd 3311
69742b76 3312 setCommonName or setCommonName{CN}
9603207d 3313 Sets Subject.CN property to the host name specified as a
69742b76
AR
3314 CN parameter or, if no explicit CN parameter was specified,
3315 extracted from the CONNECT request. It is a misconfiguration
3316 to use setCommonName without an explicit parameter for
3317 intercepted or tproxied SSL connections.
9603207d 3318
cf1c09f6
CT
3319 This clause only supports fast acl types.
3320
69742b76
AR
3321 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
3322 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
3323 corresponding adaptation algorithm to generate the certificate and
3324 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
3325 group (i.e., the first match wins within each algorithm group). If no
3326 acl(s) match, the default mimicking action takes place.
cf1c09f6 3327
4b0d23b7
CT
3328 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
3329 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
3330 CONNECT request that carries a domain name. In all other cases (CONNECT
3331 to an IP address or an intercepted SSL connection), Squid cannot detect
3332 the domain mismatch at certificate generation time when
3333 bump-server-first is used.
fb2178bb
CT
3334DOC_END
3335
41bd17a4 3336NAME: sslpassword_program
cb4f4424 3337IFDEF: USE_OPENSSL
41bd17a4 3338DEFAULT: none
3339LOC: Config.Program.ssl_password
3340TYPE: string
5473c134 3341DOC_START
41bd17a4 3342 Specify a program used for entering SSL key passphrases
3343 when using encrypted SSL certificate keys. If not specified
3344 keys must either be unencrypted, or Squid started with the -N
3345 option to allow it to query interactively for the passphrase.
7acb9ddd
HN
3346
3347 The key file name is given as argument to the program allowing
3348 selection of the right password if you have multiple encrypted
3349 keys.
5473c134 3350DOC_END
3351
95d2589c 3352COMMENT_START
9603207d 3353 OPTIONS RELATING TO EXTERNAL SSL_CRTD
95d2589c
CT
3354 -----------------------------------------------------------------------------
3355COMMENT_END
3356
3357NAME: sslcrtd_program
9603207d 3358TYPE: eol
95d2589c
CT
3359IFDEF: USE_SSL_CRTD
3360DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
3361LOC: Ssl::TheConfig.ssl_crtd
3362DOC_START
cb0b3d63
AJ
3363 Specify the location and options of the executable for certificate
3364 generator.
a2a12dec
MM
3365
3366 @DEFAULT_SSL_CRTD@ program can use a disk cache to improve response
3367 times on repeated requests. To enable caching, specify -s and -M
3368 parameters. If those parameters are not given, the program generates
3369 a new certificate on every request.
3370
95d2589c
CT
3371 For more information use:
3372 @DEFAULT_SSL_CRTD@ -h
3373DOC_END
3374
3375NAME: sslcrtd_children
3376TYPE: HelperChildConfig
3377IFDEF: USE_SSL_CRTD
3378DEFAULT: 32 startup=5 idle=1
3379LOC: Ssl::TheConfig.ssl_crtdChildren
3380DOC_START
79933cd6
AR
3381 Specifies the maximum number of certificate generation processes that
3382 Squid may spawn (numberofchildren) and several related options. Using
3383 too few of these helper processes (a.k.a. "helpers") creates request
3384 queues. Using too many helpers wastes your system resources. Squid
3385 does not support spawning more than 32 helpers.
3386
3387 Usage: numberofchildren [option]...
3388
95d2589c
CT
3389 The startup= and idle= options allow some measure of skew in your
3390 tuning.
9603207d 3391
95d2589c 3392 startup=N
9603207d 3393
95d2589c
CT
3394 Sets the minimum number of processes to spawn when Squid
3395 starts or reconfigures. When set to zero the first request will
3396 cause spawning of the first child process to handle it.
9603207d 3397
95d2589c
CT
3398 Starting too few children temporary slows Squid under load while it
3399 tries to spawn enough additional processes to cope with traffic.
9603207d 3400
95d2589c 3401 idle=N
9603207d 3402
95d2589c
CT
3403 Sets a minimum of how many processes Squid is to try and keep available
3404 at all times. When traffic begins to rise above what the existing
3405 processes can handle this many more will be spawned up to the maximum
3406 configured. A minimum setting of 1 is required.
6825b101
CT
3407
3408 queue-size=N
3409
79933cd6
AR
3410 Sets the maximum number of queued requests. A request is queued when
3411 no existing child is idle and no new child can be started due to
3412 numberofchildren limit. If the queued requests exceed queue size for
3413 more than 3 minutes squid aborts its operation. The default value is
3414 set to 2*numberofchildren.
9603207d 3415
95d2589c
CT
3416 You must have at least one ssl_crtd process.
3417DOC_END
3418
2cef0ca6
AR
3419NAME: sslcrtvalidator_program
3420TYPE: eol
cb4f4424 3421IFDEF: USE_OPENSSL
2cef0ca6
AR
3422DEFAULT: none
3423LOC: Ssl::TheConfig.ssl_crt_validator
3424DOC_START
3425 Specify the location and options of the executable for ssl_crt_validator
638402dd
AJ
3426 process.
3427
72247610 3428 Usage: sslcrtvalidator_program [ttl=...] [cache=n] path ...
14798e73
CT
3429
3430 Options:
72247610
AJ
3431
3432 cache=bytes
3433 Limits how much memory Squid can use for caching validator
3434 responses. The default is 67108864 (i.e. 64 MB).
3435 Reconfiguration purges any excess entries. To disable caching,
3436 use cache=0. Currently, cache entry sizes are seriously
3437 underestimated. Even with that bug, a typical estimate for a
3438 single cache entry size would be at least a few kilobytes (the
3439 size of the PEM certificates sent to the validator).
3440
3441 ttl=<seconds|"infinity">
3442 Approximately how long Squid may reuse the validator results
3443 for. The default is 3600 (i.e. 1 hour). Using ttl=infinity
3444 disables TTL checks. Reconfiguration does not affect TTLs of
3445 the already cached entries. To disable caching, use zero cache
3446 size, not zero TTL -- zero TTL allows reuse for the remainder
3447 of the second when the result was cached.
2cef0ca6
AR
3448DOC_END
3449
3450NAME: sslcrtvalidator_children
3451TYPE: HelperChildConfig
cb4f4424 3452IFDEF: USE_OPENSSL
413bb969 3453DEFAULT: 32 startup=5 idle=1 concurrency=1
2cef0ca6
AR
3454LOC: Ssl::TheConfig.ssl_crt_validator_Children
3455DOC_START
79933cd6
AR
3456 Specifies the maximum number of certificate validation processes that
3457 Squid may spawn (numberofchildren) and several related options. Using
3458 too few of these helper processes (a.k.a. "helpers") creates request
3459 queues. Using too many helpers wastes your system resources. Squid
3460 does not support spawning more than 32 helpers.
3461
3462 Usage: numberofchildren [option]...
9603207d 3463
2cef0ca6
AR
3464 The startup= and idle= options allow some measure of skew in your
3465 tuning.
9603207d 3466
2cef0ca6 3467 startup=N
9603207d 3468
2cef0ca6
AR
3469 Sets the minimum number of processes to spawn when Squid
3470 starts or reconfigures. When set to zero the first request will
3471 cause spawning of the first child process to handle it.
9603207d 3472
2cef0ca6
AR
3473 Starting too few children temporary slows Squid under load while it
3474 tries to spawn enough additional processes to cope with traffic.
9603207d 3475
2cef0ca6 3476 idle=N
9603207d 3477
2cef0ca6
AR
3478 Sets a minimum of how many processes Squid is to try and keep available
3479 at all times. When traffic begins to rise above what the existing
3480 processes can handle this many more will be spawned up to the maximum
3481 configured. A minimum setting of 1 is required.
4a77bb4e
CT
3482
3483 concurrency=
9603207d 3484
4a77bb4e 3485 The number of requests each certificate validator helper can handle in
2f8abb64 3486 parallel. A value of 0 indicates the certificate validator does not
dffc462a 3487 support concurrency. Defaults to 1.
9603207d 3488
4a77bb4e
CT
3489 When this directive is set to a value >= 1 then the protocol
3490 used to communicate with the helper is modified to include
3491 a request ID in front of the request/response. The request
3492 ID from the request must be echoed back with the response
3493 to that request.
6825b101
CT
3494
3495 queue-size=N
3496
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AR
3497 Sets the maximum number of queued requests. A request is queued when
3498 no existing child can accept it due to concurrency limit and no new
3499 child can be started due to numberofchildren limit. If the queued
3500 requests exceed queue size for more than 3 minutes squid aborts its
3501 operation. The default value is set to 2*numberofchildren.
9603207d 3502
2cef0ca6
AR
3503 You must have at least one ssl_crt_validator process.
3504DOC_END
3505
cccac0a2 3506COMMENT_START
41bd17a4 3507 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
cccac0a2 3508 -----------------------------------------------------------------------------
3509COMMENT_END
3510
41bd17a4 3511NAME: cache_peer
3512TYPE: peer
3513DEFAULT: none
3514LOC: Config.peers
cccac0a2 3515DOC_START
41bd17a4 3516 To specify other caches in a hierarchy, use the format:
9603207d 3517
41bd17a4 3518 cache_peer hostname type http-port icp-port [options]
9603207d 3519
41bd17a4 3520 For example,
9603207d 3521
41bd17a4 3522 # proxy icp
3523 # hostname type port port options
3524 # -------------------- -------- ----- ----- -----------
2b94f655 3525 cache_peer parent.foo.net parent 3128 3130 default
41bd17a4 3526 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
3527 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2e9993e1 3528 cache_peer example.com parent 80 0 default
9603207d 3529 cache_peer cdn.example.com sibling 3128 0
3530
2b94f655 3531 type: either 'parent', 'sibling', or 'multicast'.
9603207d 3532
2b94f655
AJ
3533 proxy-port: The port number where the peer accept HTTP requests.
3534 For other Squid proxies this is usually 3128
3535 For web servers this is usually 80
9603207d 3536
2b94f655
AJ
3537 icp-port: Used for querying neighbor caches about objects.
3538 Set to 0 if the peer does not support ICP or HTCP.
3539 See ICP and HTCP options below for additional details.
9603207d 3540
3541
2b94f655 3542 ==== ICP OPTIONS ====
9603207d 3543
2b94f655
AJ
3544 You MUST also set icp_port and icp_access explicitly when using these options.
3545 The defaults will prevent peer traffic using ICP.
9603207d 3546
3547
2b94f655 3548 no-query Disable ICP queries to this neighbor.
9603207d 3549
2b94f655
AJ
3550 multicast-responder
3551 Indicates the named peer is a member of a multicast group.
3552 ICP queries will not be sent directly to the peer, but ICP
3553 replies will be accepted from it.
9603207d 3554
2b94f655
AJ
3555 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
3556 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
9603207d 3557
2b94f655
AJ
3558 background-ping
3559 To only send ICP queries to this neighbor infrequently.
3560 This is used to keep the neighbor round trip time updated
3561 and is usually used in conjunction with weighted-round-robin.
9603207d 3562
3563
2b94f655 3564 ==== HTCP OPTIONS ====
9603207d 3565
2b94f655
AJ
3566 You MUST also set htcp_port and htcp_access explicitly when using these options.
3567 The defaults will prevent peer traffic using HTCP.
9603207d 3568
3569
2b94f655
AJ
3570 htcp Send HTCP, instead of ICP, queries to the neighbor.
3571 You probably also want to set the "icp-port" to 4827
18191440
AJ
3572 instead of 3130. This directive accepts a comma separated
3573 list of options described below.
9603207d 3574
18191440 3575 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
9603207d 3576
18191440 3577 htcp=no-clr Send HTCP to the neighbor but without
2b94f655 3578 sending any CLR requests. This cannot be used with
18191440 3579 only-clr.
9603207d 3580
18191440
AJ
3581 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
3582 This cannot be used with no-clr.
9603207d 3583
18191440 3584 htcp=no-purge-clr
2b94f655
AJ
3585 Send HTCP to the neighbor including CLRs but only when
3586 they do not result from PURGE requests.
9603207d 3587
18191440 3588 htcp=forward-clr
2b94f655 3589 Forward any HTCP CLR requests this proxy receives to the peer.
9603207d 3590
3591
2b94f655 3592 ==== PEER SELECTION METHODS ====
9603207d 3593
2b94f655
AJ
3594 The default peer selection method is ICP, with the first responding peer
3595 being used as source. These options can be used for better load balancing.
9603207d 3596
3597
2b94f655
AJ
3598 default This is a parent cache which can be used as a "last-resort"
3599 if a peer cannot be located by any of the peer-selection methods.
3600 If specified more than once, only the first is used.
9603207d 3601
2b94f655
AJ
3602 round-robin Load-Balance parents which should be used in a round-robin
3603 fashion in the absence of any ICP queries.
3604 weight=N can be used to add bias.
9603207d 3605
2b94f655
AJ
3606 weighted-round-robin
3607 Load-Balance parents which should be used in a round-robin
3608 fashion with the frequency of each parent being based on the
3609 round trip time. Closer parents are used more often.
3610 Usually used for background-ping parents.
3611 weight=N can be used to add bias.
9603207d 3612
2b94f655
AJ
3613 carp Load-Balance parents which should be used as a CARP array.
3614 The requests will be distributed among the parents based on the
3615 CARP load balancing hash function based on their weight.
9603207d 3616
2b94f655 3617 userhash Load-balance parents based on the client proxy_auth or ident username.
9603207d 3618
2b94f655 3619 sourcehash Load-balance parents based on the client source IP.
8a368316
AJ
3620
3621 multicast-siblings
3622 To be used only for cache peers of type "multicast".
3623 ALL members of this multicast group have "sibling"
2e9993e1 3624 relationship with it, not "parent". This is to a multicast
8a368316
AJ
3625 group when the requested object would be fetched only from
3626 a "parent" cache, anyway. It's useful, e.g., when
3627 configuring a pool of redundant Squid proxies, being
3628 members of the same multicast group.
9603207d 3629
3630
2b94f655 3631 ==== PEER SELECTION OPTIONS ====
9603207d 3632
2b94f655
AJ
3633 weight=N use to affect the selection of a peer during any weighted
3634 peer-selection mechanisms.
3635 The weight must be an integer; default is 1,
3636 larger weights are favored more.
3637 This option does not affect parent selection if a peering
3638 protocol is not in use.
9603207d 3639
2b94f655
AJ
3640 basetime=N Specify a base amount to be subtracted from round trip
3641 times of parents.
3642 It is subtracted before division by weight in calculating
3643 which parent to fectch from. If the rtt is less than the
3644 base time the rtt is set to a minimal value.
9603207d 3645
3c72389f
AJ
3646 ttl=N Specify a TTL to use when sending multicast ICP queries
3647 to this address.
2b94f655
AJ
3648 Only useful when sending to a multicast group.
3649 Because we don't accept ICP replies from random
3650 hosts, you must configure other group members as
3651 peers with the 'multicast-responder' option.
9603207d 3652
2b94f655
AJ
3653 no-delay To prevent access to this neighbor from influencing the
3654 delay pools.
9603207d 3655
2b94f655
AJ
3656 digest-url=URL Tell Squid to fetch the cache digest (if digests are
3657 enabled) for this host from the specified URL rather
3658 than the Squid default location.
9603207d 3659
3660
de03b596 3661 ==== CARP OPTIONS ====
9603207d 3662
de03b596
FC
3663 carp-key=key-specification
3664 use a different key than the full URL to hash against the peer.
9603207d 3665 the key-specification is a comma-separated list of the keywords
de03b596
FC
3666 scheme, host, port, path, params
3667 Order is not important.
9603207d 3668
2b94f655 3669 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
9603207d 3670
2b94f655
AJ
3671 originserver Causes this parent to be contacted as an origin server.
3672 Meant to be used in accelerator setups when the peer
3673 is a web server.
9603207d 3674
2b94f655
AJ
3675 forceddomain=name
3676 Set the Host header of requests forwarded to this peer.
3677 Useful in accelerator setups where the server (peer)
3678 expects a certain domain name but clients may request
3679 others. ie example.com or www.example.com
9603207d 3680
2b94f655 3681 no-digest Disable request of cache digests.
9603207d 3682
2b94f655
AJ
3683 no-netdb-exchange
3684 Disables requesting ICMP RTT database (NetDB).
9603207d 3685
3686
2b94f655 3687 ==== AUTHENTICATION OPTIONS ====
9603207d 3688
2b94f655
AJ
3689 login=user:password
3690 If this is a personal/workgroup proxy and your parent
3691 requires proxy authentication.
9603207d 3692
2b94f655
AJ
3693 Note: The string can include URL escapes (i.e. %20 for
3694 spaces). This also means % must be written as %%.
9603207d 3695
11e4c5e5
AJ
3696 login=PASSTHRU
3697 Send login details received from client to this peer.
3698 Both Proxy- and WWW-Authorization headers are passed
3699 without alteration to the peer.
3700 Authentication is not required by Squid for this to work.
9603207d 3701
11e4c5e5
AJ
3702 Note: This will pass any form of authentication but
3703 only Basic auth will work through a proxy unless the
3704 connection-auth options are also used.
ee0b94f4 3705
2b94f655
AJ
3706 login=PASS Send login details received from client to this peer.
3707 Authentication is not required by this option.
9603207d 3708
2b94f655
AJ
3709 If there are no client-provided authentication headers
3710 to pass on, but username and password are available
ee0b94f4
HN
3711 from an external ACL user= and password= result tags
3712 they may be sent instead.
9603207d 3713
2b94f655
AJ
3714 Note: To combine this with proxy_auth both proxies must
3715 share the same user database as HTTP only allows for
3716 a single login (one for proxy, one for origin server).
3717 Also be warned this will expose your users proxy
3718 password to the peer. USE WITH CAUTION
9603207d 3719
2b94f655
AJ
3720 login=*:password
3721 Send the username to the upstream cache, but with a
3722 fixed password. This is meant to be used when the peer
3723 is in another administrative domain, but it is still
3724 needed to identify each user.
3725 The star can optionally be followed by some extra
3726 information which is added to the username. This can
3727 be used to identify this proxy to the peer, similar to
3728 the login=username:password option above.
9603207d 3729
9ca29d23
AJ
3730 login=NEGOTIATE
3731 If this is a personal/workgroup proxy and your parent
3732 requires a secure proxy authentication.
3733 The first principal from the default keytab or defined by
9603207d 3734 the environment variable KRB5_KTNAME will be used.
3735
63f03f79
PL
3736 WARNING: The connection may transmit requests from multiple
3737 clients. Negotiate often assumes end-to-end authentication
3738 and a single-client. Which is not strictly true here.
9603207d 3739
9ca29d23
AJ
3740 login=NEGOTIATE:principal_name
3741 If this is a personal/workgroup proxy and your parent
9603207d 3742 requires a secure proxy authentication.
9ca29d23
AJ
3743 The principal principal_name from the default keytab or
3744 defined by the environment variable KRB5_KTNAME will be
3745 used.
9603207d 3746
63f03f79
PL
3747 WARNING: The connection may transmit requests from multiple
3748 clients. Negotiate often assumes end-to-end authentication
3749 and a single-client. Which is not strictly true here.
9603207d 3750
2b94f655
AJ
3751 connection-auth=on|off
3752 Tell Squid that this peer does or not support Microsoft
3753 connection oriented authentication, and any such
3754 challenges received from there should be ignored.
3755 Default is auto to automatically determine the status
3756 of the peer.
9603207d 3757
9825b398
AJ
3758 auth-no-keytab
3759 Do not use a keytab to authenticate to a peer when
3760 login=NEGOTIATE is specified. Let the GSSAPI
3761 implementation determine which already existing
3762 credentials cache to use instead.
9603207d 3763
3764
2b94f655 3765 ==== SSL / HTTPS / TLS OPTIONS ====
9603207d 3766
0ff7e52d 3767 tls Encrypt connections to this peer with TLS.
9603207d 3768
2b94f655 3769 sslcert=/path/to/ssl/certificate
51e09c08 3770 A client X.509 certificate to use when connecting to
2b94f655 3771 this peer.
9603207d 3772
2b94f655 3773 sslkey=/path/to/ssl/key
51e09c08
AJ
3774 The private key corresponding to sslcert above.
3775
3776 If sslkey= is not specified sslcert= is assumed to
3777 reference a PEM file containing both the certificate
3778 and private key.
9603207d 3779
2b94f655
AJ
3780 sslcipher=... The list of valid SSL ciphers to use when connecting
3781 to this peer.
1cc44095
AJ
3782
3783 tls-min-version=1.N
3784 The minimum TLS protocol version to permit. To control
3f5b28fe 3785 SSLv3 use the tls-options= parameter.
1cc44095
AJ
3786 Supported Values: 1.0 (default), 1.1, 1.2
3787
3f5b28fe 3788 tls-options=... Specify various TLS implementation options.
943c5f16 3789
3f5b28fe 3790 OpenSSL options most important are:
1f1f29e8 3791
3f5b28fe 3792 NO_SSLv3 Disallow the use of SSLv3
1f1f29e8 3793
943c5f16
HN
3794 SINGLE_DH_USE
3795 Always create a new key when using
3796 temporary/ephemeral DH key exchanges
1f1f29e8 3797
ce0adf1a 3798 NO_TICKET
1f1f29e8
AJ
3799 Disable use of RFC5077 session tickets.
3800 Some servers may have problems
3801 understanding the TLS extension due
3802 to ambiguous specification in RFC4507.
3803
943c5f16
HN
3804 ALL Enable various bug workarounds
3805 suggested as "harmless" by OpenSSL
3806 Be warned that this reduces SSL/TLS
3807 strength to some attacks.
3808
3809 See the OpenSSL SSL_CTX_set_options documentation for a
3810 more complete list.
3f5b28fe
AJ
3811
3812 GnuTLS options most important are:
3813
3814 %NO_TICKETS
3815 Disable use of RFC5077 session tickets.
3816 Some servers may have problems
3817 understanding the TLS extension due
3818 to ambiguous specification in RFC4507.
3819
3820 See the GnuTLS Priority Strings documentation
3821 for a more complete list.
3822 http://www.gnutls.org/manual/gnutls.html#Priority-Strings
3823
86a84cc0
AJ
3824 tls-cafile= PEM file containing CA certificates to use when verifying
3825 the peer certificate. May be repeated to load multiple files.
9603207d 3826
2b94f655
AJ
3827 sslcapath=... A directory containing additional CA certificates to
3828 use when verifying the peer certificate.
86a84cc0 3829 Requires OpenSSL or LibreSSL.
9603207d 3830
2b94f655
AJ
3831 sslcrlfile=... A certificate revocation list file to use when
3832 verifying the peer certificate.
9603207d 3833
2b94f655 3834 sslflags=... Specify various flags modifying the SSL implementation:
9603207d 3835
41bd17a4 3836 DONT_VERIFY_PEER
3837 Accept certificates even if they fail to
3838 verify.
1f1f29e8 3839
41bd17a4 3840 DONT_VERIFY_DOMAIN
3841 Don't verify the peer certificate
3842 matches the server name
9603207d 3843
2b94f655
AJ
3844 ssldomain= The peer name as advertised in it's certificate.
3845 Used for verifying the correctness of the received peer
3846 certificate. If not specified the peer hostname will be
3847 used.
9603207d 3848
bad9c5e4 3849 front-end-https[=off|on|auto]
2b94f655
AJ
3850 Enable the "Front-End-Https: On" header needed when
3851 using Squid as a SSL frontend in front of Microsoft OWA.
3852 See MS KB document Q307347 for details on this header.
3853 If set to auto the header will only be added if the
3854 request is forwarded as a https:// URL.
9603207d 3855
435c72b0
AJ
3856 tls-default-ca[=off]
3857 Whether to use the system Trusted CAs. Default is ON.
9603207d 3858
b05d749d
AJ
3859 tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
3860
2b94f655 3861 ==== GENERAL OPTIONS ====
9603207d 3862
2b94f655
AJ
3863 connect-timeout=N
3864 A peer-specific connect timeout.
3865 Also see the peer_connect_timeout directive.
9603207d 3866
2b94f655
AJ
3867 connect-fail-limit=N
3868 How many times connecting to a peer must fail before
e8dca475
CT
3869 it is marked as down. Standby connection failures
3870 count towards this limit. Default is 10.
9603207d 3871
2b94f655
AJ
3872 allow-miss Disable Squid's use of only-if-cached when forwarding
3873 requests to siblings. This is primarily useful when
a5bb0c26
AR
3874 icp_hit_stale is used by the sibling. Excessive use
3875 of this option may result in forwarding loops. One way
3876 to prevent peering loops when using this option, is to
3877 deny cache peer usage on requests from a peer:
3878 acl fromPeer ...
3879 cache_peer_access peerName deny fromPeer
9603207d 3880
e8dca475
CT
3881 max-conn=N Limit the number of concurrent connections the Squid
3882 may open to this peer, including already opened idle
3883 and standby connections. There is no peer-specific
3884 connection limit by default.
9603207d 3885
e8dca475
CT
3886 A peer exceeding the limit is not used for new
3887 requests unless a standby connection is available.
9603207d 3888
e8dca475
CT
3889 max-conn currently works poorly with idle persistent
3890 connections: When a peer reaches its max-conn limit,
3891 and there are idle persistent connections to the peer,
3892 the peer may not be selected because the limiting code
3893 does not know whether Squid can reuse those idle
3894 connections.
9603207d 3895
e8dca475
CT
3896 standby=N Maintain a pool of N "hot standby" connections to an
3897 UP peer, available for requests when no idle
3898 persistent connection is available (or safe) to use.
3899 By default and with zero N, no such pool is maintained.
3900 N must not exceed the max-conn limit (if any).
9603207d 3901
e8dca475
CT
3902 At start or after reconfiguration, Squid opens new TCP
3903 standby connections until there are N connections
3904 available and then replenishes the standby pool as
3905 opened connections are used up for requests. A used
3906 connection never goes back to the standby pool, but
3907 may go to the regular idle persistent connection pool
3908 shared by all peers and origin servers.
9603207d 3909
e8dca475
CT
3910 Squid never opens multiple new standby connections
3911 concurrently. This one-at-a-time approach minimizes
3912 flooding-like effect on peers. Furthermore, just a few
3913 standby connections should be sufficient in most cases
3914 to supply most new requests with a ready-to-use
3915 connection.
9603207d 3916
e8dca475
CT
3917 Standby connections obey server_idle_pconn_timeout.
3918 For the feature to work as intended, the peer must be
3919 configured to accept and keep them open longer than
3920 the idle timeout at the connecting Squid, to minimize
3921 race conditions typical to idle used persistent
3922 connections. Default request_timeout and
3923 server_idle_pconn_timeout values ensure such a
3924 configuration.
9603207d 3925
2b94f655
AJ
3926 name=xxx Unique name for the peer.
3927 Required if you have multiple peers on the same host
3928 but different ports.
3929 This name can be used in cache_peer_access and similar
a5bb0c26 3930 directives to identify the peer.
2b94f655
AJ
3931 Can be used by outgoing access controls through the
3932 peername ACL type.
9603207d 3933
b0758e04
AJ
3934 no-tproxy Do not use the client-spoof TPROXY support when forwarding
3935 requests to this peer. Use normal address selection instead.
0d901ef4 3936 This overrides the spoof_client_ip ACL.
9603207d 3937
2b94f655 3938 proxy-only objects fetched from the peer will not be stored locally.
9603207d 3939
41bd17a4 3940DOC_END
cccac0a2 3941
41bd17a4 3942NAME: cache_peer_access
3943TYPE: peer_access
3944DEFAULT: none
a5bb0c26 3945DEFAULT_DOC: No peer usage restrictions.
41bd17a4 3946LOC: none
3947DOC_START
a5bb0c26 3948 Restricts usage of cache_peer proxies.
cccac0a2 3949
638402dd 3950 Usage:
a5bb0c26
AR
3951 cache_peer_access peer-name allow|deny [!]aclname ...
3952
3953 For the required peer-name parameter, use either the value of the
3954 cache_peer name=value parameter or, if name=value is missing, the
3955 cache_peer hostname parameter.
3956
3957 This directive narrows down the selection of peering candidates, but
3958 does not determine the order in which the selected candidates are
3959 contacted. That order is determined by the peer selection algorithms
3960 (see PEER SELECTION sections in the cache_peer documentation).
3961
3962 If a deny rule matches, the corresponding peer will not be contacted
3963 for the current transaction -- Squid will not send ICP queries and
3964 will not forward HTTP requests to that peer. An allow match leaves
3965 the corresponding peer in the selection. The first match for a given
3966 peer wins for that peer.
3967
3968 The relative order of cache_peer_access directives for the same peer
3969 matters. The relative order of any two cache_peer_access directives
3970 for different peers does not matter. To ease interpretation, it is a
3971 good idea to group cache_peer_access directives for the same peer
3972 together.
3973
3974 A single cache_peer_access directive may be evaluated multiple times
3975 for a given transaction because individual peer selection algorithms
3976 may check it independently from each other. These redundant checks
3977 may be optimized away in future Squid versions.
3978
3979 This clause only supports fast acl types.
3980 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
dd9b1776 3981
41bd17a4 3982DOC_END
dd9b1776 3983
41bd17a4 3984NAME: neighbor_type_domain
3985TYPE: hostdomaintype
3986DEFAULT: none
638402dd 3987DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
41bd17a4 3988LOC: none
3989DOC_START
638402dd
AJ
3990 Modify the cache_peer neighbor type when passing requests
3991 about specific domains to the peer.
cccac0a2 3992
638402dd
AJ
3993 Usage:
3994 neighbor_type_domain neighbor parent|sibling domain domain ...
6bf4f823 3995
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3996 For example:
3997 cache_peer foo.example.com parent 3128 3130
3998 neighbor_type_domain foo.example.com sibling .au .de
6bf4f823 3999
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4000 The above configuration treats all requests to foo.example.com as a
4001 parent proxy unless the request is for a .au or .de ccTLD domain name.
41bd17a4 4002DOC_END
6bf4f823 4003
41bd17a4 4004NAME: dead_peer_timeout
4005COMMENT: (seconds)
4006DEFAULT: 10 seconds
4007TYPE: time_t
4008LOC: Config.Timeout.deadPeer
4009DOC_START
4010 This controls how long Squid waits to declare a peer cache
4011 as "dead." If there are no ICP replies received in this
4012 amount of time, Squid will declare the peer dead and not
4013 expect to receive any further ICP replies. However, it
4014 continues to send ICP queries, and will mark the peer as
4015 alive upon receipt of the first subsequent ICP reply.
699acd19 4016
41bd17a4 4017 This timeout also affects when Squid expects to receive ICP
4018 replies from peers. If more than 'dead_peer' seconds have
4019 passed since the last ICP reply was received, Squid will not
4020 expect to receive an ICP reply on the next query. Thus, if
4021 your time between requests is greater than this timeout, you
4022 will see a lot of requests sent DIRECT to origin servers
4023 instead of to your parents.
4024DOC_END
cccac0a2 4025
437823b4 4026NAME: forward_max_tries
6c367206 4027DEFAULT: 25
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4028TYPE: int
4029LOC: Config.forward_max_tries
4030DOC_START
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4031 Limits the number of attempts to forward the request.
4032
4033 For the purpose of this limit, Squid counts all high-level request
4034 forwarding attempts, including any same-destination retries after
4035 certain persistent connection failures and any attempts to use a
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4036 different peer. However, these low-level attempts are not counted:
4037 * connection reopening attempts (enabled using connect_retries)
4038 * unfinished Happy Eyeballs connection attempts (prevented by setting
4039 happy_eyeballs_connect_limit to 0)
9603207d 4040
3eebd267 4041 See also: forward_timeout and connect_retries.
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4042DOC_END
4043
41bd17a4 4044COMMENT_START
4045 MEMORY CACHE OPTIONS
4046 -----------------------------------------------------------------------------
4047COMMENT_END
4048
4049NAME: cache_mem
4050COMMENT: (bytes)
4051TYPE: b_size_t
df2eec10 4052DEFAULT: 256 MB
41bd17a4 4053LOC: Config.memMaxSize
6b698a21 4054DOC_START
41bd17a4 4055 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
4056 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
4057 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
4058 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
4059
4060 'cache_mem' specifies the ideal amount of memory to be used
4061 for:
4062 * In-Transit objects
4063 * Hot Objects
4064 * Negative-Cached objects
4065
4066 Data for these objects are stored in 4 KB blocks. This
4067 parameter specifies the ideal upper limit on the total size of
4068 4 KB blocks allocated. In-Transit objects take the highest
4069 priority.
4070
4071 In-transit objects have priority over the others. When
4072 additional space is needed for incoming data, negative-cached
4073 and hot objects will be released. In other words, the
4074 negative-cached and hot objects will fill up any unused space
4075 not needed for in-transit objects.
4076
4077 If circumstances require, this limit will be exceeded.
4078 Specifically, if your incoming request rate requires more than
4079 'cache_mem' of memory to hold in-transit objects, Squid will
4080 exceed this limit to satisfy the new requests. When the load
4081 decreases, blocks will be freed until the high-water mark is
4082 reached. Thereafter, blocks will be used to store hot
4083 objects.
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4084
4085 If shared memory caching is enabled, Squid does not use the shared
4086 cache space for in-transit objects, but they still consume as much
4087 local memory as they need. For more details about the shared memory
4088 cache, see memory_cache_shared.
6b698a21 4089DOC_END
0976f8db 4090
41bd17a4 4091NAME: maximum_object_size_in_memory
4092COMMENT: (bytes)
4093TYPE: b_size_t
df2eec10 4094DEFAULT: 512 KB
41bd17a4 4095LOC: Config.Store.maxInMemObjSize
6b698a21 4096DOC_START
41bd17a4 4097 Objects greater than this size will not be attempted to kept in
4098 the memory cache. This should be set high enough to keep objects
4099 accessed frequently in memory to improve performance whilst low
4100 enough to keep larger objects from hoarding cache_mem.
6b698a21 4101DOC_END
0976f8db 4102
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4103NAME: memory_cache_shared
4104COMMENT: on|off
4105TYPE: YesNoNone
4106LOC: Config.memShared
4107DEFAULT: none
70f856bc 4108DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
57af1e3f
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4109DOC_START
4110 Controls whether the memory cache is shared among SMP workers.
4111
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4112 The shared memory cache is meant to occupy cache_mem bytes and replace
4113 the non-shared memory cache, although some entities may still be
4114 cached locally by workers for now (e.g., internal and in-transit
4115 objects may be served from a local memory cache even if shared memory
4116 caching is enabled).
4117
65b81b27 4118 By default, the memory cache is shared if and only if all of the
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4119 following conditions are satisfied: Squid runs in SMP mode with
4120 multiple workers, cache_mem is positive, and Squid environment
4121 supports required IPC primitives (e.g., POSIX shared memory segments
4122 and GCC-style atomic operations).
4123
4124 To avoid blocking locks, shared memory uses opportunistic algorithms
4125 that do not guarantee that every cachable entity that could have been
4126 shared among SMP workers will actually be shared.
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4127DOC_END
4128
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4129NAME: memory_cache_mode
4130TYPE: memcachemode
4131LOC: Config
4132DEFAULT: always
638402dd 4133DEFAULT_DOC: Keep the most recently fetched objects in memory
ff4b33f4 4134DOC_START
ea21d497 4135 Controls which objects to keep in the memory cache (cache_mem)
ff4b33f4 4136
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HN
4137 always Keep most recently fetched objects in memory (default)
4138
4139 disk Only disk cache hits are kept in memory, which means
4140 an object must first be cached on disk and then hit
4141 a second time before cached in memory.
4142
4143 network Only objects fetched from network is kept in memory
ff4b33f4
HN
4144DOC_END
4145
41bd17a4 4146NAME: memory_replacement_policy
4147TYPE: removalpolicy
4148LOC: Config.memPolicy
4149DEFAULT: lru
6b698a21 4150DOC_START
41bd17a4 4151 The memory replacement policy parameter determines which
4152 objects are purged from memory when memory space is needed.
7f7db318 4153
638402dd 4154 See cache_replacement_policy for details on algorithms.
41bd17a4 4155DOC_END
6b698a21 4156
41bd17a4 4157COMMENT_START
4158 DISK CACHE OPTIONS
4159 -----------------------------------------------------------------------------
4160COMMENT_END
6b698a21 4161
41bd17a4 4162NAME: cache_replacement_policy
4163TYPE: removalpolicy
4164LOC: Config.replPolicy
4165DEFAULT: lru
4166DOC_START
4167 The cache replacement policy parameter determines which
4168 objects are evicted (replaced) when disk space is needed.
6b698a21 4169
41bd17a4 4170 lru : Squid's original list based LRU policy
4171 heap GDSF : Greedy-Dual Size Frequency
4172 heap LFUDA: Least Frequently Used with Dynamic Aging
4173 heap LRU : LRU policy implemented using a heap
6b698a21 4174
638402dd 4175 Applies to any cache_dir lines listed below this directive.
7f7db318 4176
41bd17a4 4177 The LRU policies keeps recently referenced objects.
0976f8db 4178
41bd17a4 4179 The heap GDSF policy optimizes object hit rate by keeping smaller
4180 popular objects in cache so it has a better chance of getting a
4181 hit. It achieves a lower byte hit rate than LFUDA though since
4182 it evicts larger (possibly popular) objects.
0976f8db 4183
41bd17a4 4184 The heap LFUDA policy keeps popular objects in cache regardless of
4185 their size and thus optimizes byte hit rate at the expense of
4186 hit rate since one large, popular object will prevent many
4187 smaller, slightly less popular objects from being cached.
0976f8db 4188
41bd17a4 4189 Both policies utilize a dynamic aging mechanism that prevents
4190 cache pollution that can otherwise occur with frequency-based
4191 replacement policies.
7d90757b 4192
41bd17a4 4193 NOTE: if using the LFUDA replacement policy you should increase
b51ec8c8 4194 the value of maximum_object_size above its default of 4 MB to
41bd17a4 4195 to maximize the potential byte hit rate improvement of LFUDA.
dc1af3cf 4196
41bd17a4 4197 For more information about the GDSF and LFUDA cache replacement
4198 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
4199 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
6b698a21 4200DOC_END
0976f8db 4201
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4202NAME: minimum_object_size
4203COMMENT: (bytes)
4204TYPE: b_int64_t
4205DEFAULT: 0 KB
4206DEFAULT_DOC: no limit
4207LOC: Config.Store.minObjectSize
4208DOC_START
4209 Objects smaller than this size will NOT be saved on disk. The
4210 value is specified in bytes, and the default is 0 KB, which
4211 means all responses can be stored.
4212DOC_END
4213
4214NAME: maximum_object_size
4215COMMENT: (bytes)
4216TYPE: b_int64_t
4217DEFAULT: 4 MB
4218LOC: Config.Store.maxObjectSize
4219DOC_START
499f852c 4220 Set the default value for max-size parameter on any cache_dir.
a345387f 4221 The value is specified in bytes, and the default is 4 MB.
9603207d 4222
a345387f
AJ
4223 If you wish to get a high BYTES hit ratio, you should probably
4224 increase this (one 32 MB object hit counts for 3200 10KB
4225 hits).
9603207d 4226
a345387f
AJ
4227 If you wish to increase hit ratio more than you want to
4228 save bandwidth you should leave this low.
9603207d 4229
a345387f
AJ
4230 NOTE: if using the LFUDA replacement policy you should increase
4231 this value to maximize the byte hit rate improvement of LFUDA!
4232 See cache_replacement_policy for a discussion of this policy.
4233DOC_END
4234
41bd17a4 4235NAME: cache_dir
4236TYPE: cachedir
4237DEFAULT: none
2f8abb64 4238DEFAULT_DOC: No disk cache. Store cache objects only in memory.
41bd17a4 4239LOC: Config.cacheSwap
6b698a21 4240DOC_START
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4241 Format:
4242 cache_dir Type Directory-Name Fs-specific-data [options]
0976f8db 4243
41bd17a4 4244 You can specify multiple cache_dir lines to spread the
4245 cache among different disk partitions.
0976f8db 4246
41bd17a4 4247 Type specifies the kind of storage system to use. Only "ufs"
4248 is built by default. To enable any of the other storage systems
4249 see the --enable-storeio configure option.
0976f8db 4250
41bd17a4 4251 'Directory' is a top-level directory where cache swap
4252 files will be stored. If you want to use an entire disk
4253 for caching, this can be the mount-point directory.
4254 The directory must exist and be writable by the Squid
4255 process. Squid will NOT create this directory for you.
0976f8db 4256
acf69d74
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4257 In SMP configurations, cache_dir must not precede the workers option
4258 and should use configuration macros or conditionals to give each
4259 worker interested in disk caching a dedicated cache directory.
4260
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4261
4262 ==== The ufs store type ====
0976f8db 4263
41bd17a4 4264 "ufs" is the old well-known Squid storage format that has always
4265 been there.
0976f8db 4266
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AJ
4267 Usage:
4268 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
0976f8db 4269
41bd17a4 4270 'Mbytes' is the amount of disk space (MB) to use under this
4271 directory. The default is 100 MB. Change this to suit your
4272 configuration. Do NOT put the size of your disk drive here.
4273 Instead, if you want Squid to use the entire disk drive,
4274 subtract 20% and use that value.
0976f8db 4275
56fba4d0 4276 'L1' is the number of first-level subdirectories which
41bd17a4 4277 will be created under the 'Directory'. The default is 16.
0976f8db 4278
56fba4d0 4279 'L2' is the number of second-level subdirectories which
41bd17a4 4280 will be created under each first-level directory. The default
4281 is 256.
0976f8db 4282
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4283
4284 ==== The aufs store type ====
7f7db318 4285
41bd17a4 4286 "aufs" uses the same storage format as "ufs", utilizing
4287 POSIX-threads to avoid blocking the main Squid process on
4288 disk-I/O. This was formerly known in Squid as async-io.
38f9c547 4289
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AJ
4290 Usage:
4291 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
38f9c547 4292
41bd17a4 4293 see argument descriptions under ufs above
38f9c547 4294
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4295
4296 ==== The diskd store type ====
38f9c547 4297
41bd17a4 4298 "diskd" uses the same storage format as "ufs", utilizing a
4299 separate process to avoid blocking the main Squid process on
4300 disk-I/O.
4c3ef9b2 4301
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4302 Usage:
4303 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
0976f8db 4304
41bd17a4 4305 see argument descriptions under ufs above
0976f8db 4306
41bd17a4 4307 Q1 specifies the number of unacknowledged I/O requests when Squid
4308 stops opening new files. If this many messages are in the queues,
4309 Squid won't open new files. Default is 64
0976f8db 4310
41bd17a4 4311 Q2 specifies the number of unacknowledged messages when Squid
4312 starts blocking. If this many messages are in the queues,
4313 Squid blocks until it receives some replies. Default is 72
0976f8db 4314
41bd17a4 4315 When Q1 < Q2 (the default), the cache directory is optimized
4316 for lower response time at the expense of a decrease in hit
4317 ratio. If Q1 > Q2, the cache directory is optimized for
4318 higher hit ratio at the expense of an increase in response
4319 time.
0976f8db 4320
e2851fe7 4321
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AJ
4322 ==== The rock store type ====
4323
4324 Usage:
e51ce7da 4325 cache_dir rock Directory-Name Mbytes [options]
e2851fe7 4326
2e55f083 4327 The Rock Store type is a database-style storage. All cached
e51ce7da
AR
4328 entries are stored in a "database" file, using fixed-size slots.
4329 A single entry occupies one or more slots.
e2851fe7 4330
3e1dfe3d
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4331 If possible, Squid using Rock Store creates a dedicated kid
4332 process called "disker" to avoid blocking Squid worker(s) on disk
4333 I/O. One disker kid is created for each rock cache_dir. Diskers
4334 are created only when Squid, running in daemon mode, has support
4335 for the IpcIo disk I/O module.
4336
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4337 swap-timeout=msec: Squid will not start writing a miss to or
4338 reading a hit from disk if it estimates that the swap operation
4339 will take more than the specified number of milliseconds. By
4340 default and when set to zero, disables the disk I/O time limit
4341 enforcement. Ignored when using blocking I/O module because
4342 blocking synchronous I/O does not allow Squid to estimate the
4343 expected swap wait time.
4344
df881a0f 4345 max-swap-rate=swaps/sec: Artificially limits disk access using
1e614370 4346 the specified I/O rate limit. Swap out requests that
df881a0f 4347 would cause the average I/O rate to exceed the limit are
1e614370
DK
4348 delayed. Individual swap in requests (i.e., hits or reads) are
4349 not delayed, but they do contribute to measured swap rate and
4350 since they are placed in the same FIFO queue as swap out
4351 requests, they may wait longer if max-swap-rate is smaller.
4352 This is necessary on file systems that buffer "too
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4353 many" writes and then start blocking Squid and other processes
4354 while committing those writes to disk. Usually used together
4355 with swap-timeout to avoid excessive delays and queue overflows
4356 when disk demand exceeds available disk "bandwidth". By default
4357 and when set to zero, disables the disk I/O rate limit
4358 enforcement. Currently supported by IpcIo module only.
4359
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4360 slot-size=bytes: The size of a database "record" used for
4361 storing cached responses. A cached response occupies at least
4362 one slot and all database I/O is done using individual slots so
4363 increasing this parameter leads to more disk space waste while
4364 decreasing it leads to more disk I/O overheads. Should be a
4365 multiple of your operating system I/O page size. Defaults to
4366 16KBytes. A housekeeping header is stored with each slot and
4367 smaller slot-sizes will be rejected. The header is smaller than
4368 100 bytes.
4369
df881a0f 4370
638402dd 4371 ==== COMMON OPTIONS ====
0976f8db 4372
638402dd
AJ
4373 no-store no new objects should be stored to this cache_dir.
4374
4375 min-size=n the minimum object size in bytes this cache_dir
4376 will accept. It's used to restrict a cache_dir
4377 to only store large objects (e.g. AUFS) while
4378 other stores are optimized for smaller objects
73656056 4379 (e.g. Rock).
638402dd 4380 Defaults to 0.
0976f8db 4381
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AJ
4382 max-size=n the maximum object size in bytes this cache_dir
4383 supports.
499f852c
A
4384 The value in maximum_object_size directive sets
4385 the default unless more specific details are
4386 available (ie a small store capacity).
b6662ffd 4387
41bd17a4 4388 Note: To make optimal use of the max-size limits you should order
638402dd 4389 the cache_dir lines with the smallest max-size value first.
0976f8db 4390
47f0eaea 4391CONFIG_START
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AJ
4392
4393# Uncomment and adjust the following to add a disk cache directory.
4394#cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
47f0eaea 4395CONFIG_END
6b698a21 4396DOC_END
0976f8db 4397
41bd17a4 4398NAME: store_dir_select_algorithm
4399TYPE: string
4400LOC: Config.store_dir_select_algorithm
4401DEFAULT: least-load
6b698a21 4402DOC_START
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AJ
4403 How Squid selects which cache_dir to use when the response
4404 object will fit into more than one.
4405
4406 Regardless of which algorithm is used the cache_dir min-size
4407 and max-size parameters are obeyed. As such they can affect
4408 the selection algorithm by limiting the set of considered
4409 cache_dir.
4410
4411 Algorithms:
4412
4413 least-load
4414
4415 This algorithm is suited to caches with similar cache_dir
4416 sizes and disk speeds.
4417
4418 The disk with the least I/O pending is selected.
4419 When there are multiple disks with the same I/O load ranking
4420 the cache_dir with most available capacity is selected.
4421
4422 When a mix of cache_dir sizes are configured the faster disks
4423 have a naturally lower I/O loading and larger disks have more
4424 capacity. So space used to store objects and data throughput
4425 may be very unbalanced towards larger disks.
4426
4427
4428 round-robin
4429
4430 This algorithm is suited to caches with unequal cache_dir
4431 disk sizes.
4432
4433 Each cache_dir is selected in a rotation. The next suitable
4434 cache_dir is used.
4435
4436 Available cache_dir capacity is only considered in relation
4437 to whether the object will fit and meets the min-size and
4438 max-size parameters.
4439
4440 Disk I/O loading is only considered to prevent overload on slow
4441 disks. This algorithm does not spread objects by size, so any
4442 I/O loading per-disk may appear very unbalanced and volatile.
4443
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4444 If several cache_dirs use similar min-size, max-size, or other
4445 limits to to reject certain responses, then do not group such
4446 cache_dir lines together, to avoid round-robin selection bias
4447 towards the first cache_dir after the group. Instead, interleave
4448 cache_dir lines from different groups. For example:
4449
4450 store_dir_select_algorithm round-robin
4451 cache_dir rock /hdd1 ... min-size=100000
4452 cache_dir rock /ssd1 ... max-size=99999
4453 cache_dir rock /hdd2 ... min-size=100000
4454 cache_dir rock /ssd2 ... max-size=99999
4455 cache_dir rock /hdd3 ... min-size=100000
4456 cache_dir rock /ssd3 ... max-size=99999
6b698a21 4457DOC_END
0976f8db 4458
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EB
4459NAME: paranoid_hit_validation
4460COMMENT: time-units-small
4461TYPE: time_nanoseconds
4462DEFAULT: 0
4463DEFAULT_DOC: validation disabled
4464LOC: Config.paranoid_hit_validation
4465DOC_START
4466 Controls whether Squid should perform paranoid validation of cache entry
4467 metadata integrity every time a cache entry is hit. This low-level
4468 validation should always succeed. Each failed validation results in a
4469 cache miss, a BUG line reported to cache.log, and the invalid entry
4470 marked as unusable (and eventually purged from the cache).
4471
4472 Squid can only validate shared cache memory and rock cache_dir entries.
4473
4474 * Zero (default) value means that the validation is disabled.
4475
4476 * Positive values enable validation:
4477 - values less than 1 day approximate the maximum time that Squid is allowed
4478 to spend validating a single cache hit.
4479 - values greater or equal to 1 day are considered as no limitation:
4480 in this case all checks will be performed, regardless of how much time
4481 they take.
4482
4483 Hits are usually stored using 16KB slots (for rock, the size is
4484 configurable via cache_dir slot-size). Larger hits require scanning more
4485 slots and, hence, take more time. When validation is enabled, at least one
4486 slot is always validated, regardless of the configured time limit.
4487
4488 A worker process validating an entry cannot do anything else (i.e. the
4489 validation is blocking). The validation overhead is environment dependent,
4490 but developers have observed Squid spending 3-10 microseconds to check each
4491 slot of a Rock or shared memory hit entry. If Squid cuts validation short
4492 because it runs out of configured time, it treats the entry as valid.
4493
4494 When hit validation is enabled, its statistics is included in Cache
4495 Manager mgr:counters, mgr:5min, and mgr:60min reports.
4496DOC_END
4497
41bd17a4 4498NAME: max_open_disk_fds
4499TYPE: int
4500LOC: Config.max_open_disk_fds
4501DEFAULT: 0
638402dd 4502DEFAULT_DOC: no limit
6b698a21 4503DOC_START
41bd17a4 4504 To avoid having disk as the I/O bottleneck Squid can optionally
4505 bypass the on-disk cache if more than this amount of disk file
4506 descriptors are open.
4507
4508 A value of 0 indicates no limit.
6b698a21 4509DOC_END
0976f8db 4510
41bd17a4 4511NAME: cache_swap_low
4512COMMENT: (percent, 0-100)
5473c134 4513TYPE: int
41bd17a4 4514DEFAULT: 90
4515LOC: Config.Swap.lowWaterMark
638402dd 4516DOC_START
5f662601
AJ
4517 The low-water mark for AUFS/UFS/diskd cache object eviction by
4518 the cache_replacement_policy algorithm.
4519
4520 Removal begins when the swap (disk) usage of a cache_dir is
4521 above this low-water mark and attempts to maintain utilization
4522 near the low-water mark.
4523
4524 As swap utilization increases towards the high-water mark set
2f8abb64 4525 by cache_swap_high object eviction becomes more aggressive.
5f662601
AJ
4526
4527 The value difference in percentages between low- and high-water
7bcaf76f 4528 marks represent an eviction rate of 300 objects per second and
2f8abb64 4529 the rate continues to scale in aggressiveness by multiples of
5f662601 4530 this above the high-water mark.
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AJ
4531
4532 Defaults are 90% and 95%. If you have a large cache, 5% could be
4533 hundreds of MB. If this is the case you may wish to set these
4534 numbers closer together.
4535
5f662601 4536 See also cache_swap_high and cache_replacement_policy
638402dd 4537DOC_END
41bd17a4 4538
4539NAME: cache_swap_high
4540COMMENT: (percent, 0-100)
4541TYPE: int
4542DEFAULT: 95
4543LOC: Config.Swap.highWaterMark
6b698a21 4544DOC_START
5f662601
AJ
4545 The high-water mark for AUFS/UFS/diskd cache object eviction by
4546 the cache_replacement_policy algorithm.
4547
4548 Removal begins when the swap (disk) usage of a cache_dir is
4549 above the low-water mark set by cache_swap_low and attempts to
4550 maintain utilization near the low-water mark.
4551
4552 As swap utilization increases towards this high-water mark object
2f8abb64 4553 eviction becomes more aggressive.
5f662601
AJ
4554
4555 The value difference in percentages between low- and high-water
7bcaf76f 4556 marks represent an eviction rate of 300 objects per second and
2f8abb64 4557 the rate continues to scale in aggressiveness by multiples of
5f662601 4558 this above the high-water mark.
41bd17a4 4559
4560 Defaults are 90% and 95%. If you have a large cache, 5% could be
4561 hundreds of MB. If this is the case you may wish to set these
4562 numbers closer together.
638402dd 4563
5f662601 4564 See also cache_swap_low and cache_replacement_policy
6b698a21 4565DOC_END
0976f8db 4566
5473c134 4567COMMENT_START
41bd17a4 4568 LOGFILE OPTIONS
5473c134 4569 -----------------------------------------------------------------------------
4570COMMENT_END
0976f8db 4571
41bd17a4 4572NAME: logformat
4573TYPE: logformat
20efa1c2 4574LOC: Log::TheConfig
5473c134 4575DEFAULT: none
638402dd 4576DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
6b698a21 4577DOC_START
41bd17a4 4578 Usage:
0976f8db 4579
41bd17a4 4580 logformat <name> <format specification>
0976f8db 4581
41bd17a4 4582 Defines an access log format.
6b698a21 4583
41bd17a4 4584 The <format specification> is a string with embedded % format codes
5473c134 4585
bec110e4
EB
4586 % format codes all follow the same basic structure where all
4587 components but the formatcode are optional and usually unnecessary,
4588 especially when dealing with common codes.
6b698a21 4589
bec110e4 4590 % [encoding] [-] [[0]width] [{arg}] formatcode [{arg}]
0976f8db 4591
bec110e4
EB
4592 encoding escapes or otherwise protects "special" characters:
4593
4594 " Quoted string encoding where quote(") and
4595 backslash(\) characters are \-escaped while
4596 CR, LF, and TAB characters are encoded as \r,
4597 \n, and \t two-character sequences.
4598
4599 [ Custom Squid encoding where percent(%), square
4600 brackets([]), backslash(\) and characters with
4601 codes outside of [32,126] range are %-encoded.
4602 SP is not encoded. Used by log_mime_hdrs.
4603
4604 # URL encoding (a.k.a. percent-encoding) where
4605 all URL unsafe and control characters (per RFC
4606 1738) are %-encoded.
4607
4608 / Shell-like encoding where quote(") and
4609 backslash(\) characters are \-escaped while CR
4610 and LF characters are encoded as \r and \n
4611 two-character sequences. Values containing SP
4612 character(s) are surrounded by quotes(").
4613
4614 ' Raw/as-is encoding with no escaping/quoting.
4615
4616 Default encoding: When no explicit encoding is
4617 specified, each %code determines its own encoding.
4618 Most %codes use raw/as-is encoding, but some codes use
4619 a so called "pass-through URL encoding" where all URL
4620 unsafe and control characters (per RFC 1738) are
4621 %-encoded, but the percent character(%) is left as is.
5473c134 4622
41bd17a4 4623 - left aligned
c32c6db7
AR
4624
4625 width minimum and/or maximum field width:
4626 [width_min][.width_max]
e2851fe7
AR
4627 When minimum starts with 0, the field is zero-padded.
4628 String values exceeding maximum width are truncated.
c32c6db7 4629
4e56d7f6
AJ
4630 {arg} argument such as header name etc. This field may be
4631 placed before or after the token, but not both at once.
5473c134 4632
41bd17a4 4633 Format codes:
5473c134 4634
3ff65596 4635 % a literal % character
f4b68e1a
AJ
4636 sn Unique sequence number per log line entry
4637 err_code The ID of an error response served by Squid or
4638 a similar internal error identifier.
4639 err_detail Additional err_code-dependent error information.
c7bcf010 4640 note The annotation specified by the argument. Also
d7f4a0b7
CT
4641 logs the adaptation meta headers set by the
4642 adaptation_meta configuration parameter.
c7bcf010
CT
4643 If no argument given all annotations logged.
4644 The argument may include a separator to use with
4645 annotation values:
4646 name[:separator]
4647 By default, multiple note values are separated with ","
4648 and multiple notes are separated with "\r\n".
4649 When logging named notes with %{name}note, the
4650 explicitly configured separator is used between note
4651 values. When logging all notes with %note, the
4652 explicitly configured separator is used between
4653 individual notes. There is currently no way to
4654 specify both value and notes separators when logging
4655 all notes with %note.
7cfd3a41
EB
4656 master_xaction The master transaction identifier is an unsigned
4657 integer. These IDs are guaranteed to monotonically
4658 increase within a single worker process lifetime, with
4659 higher values corresponding to transactions that were
4660 accepted or initiated later. Due to current implementation
4661 deficiencies, some IDs are skipped (i.e. never logged).
4662 Concurrent workers and restarted workers use similar,
4663 overlapping sequences of master transaction IDs.
f4b68e1a
AJ
4664
4665 Connection related format codes:
4666
41bd17a4 4667 >a Client source IP address
4668 >A Client FQDN
4669 >p Client source port
8652f8e7
AJ
4670 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
4671 >la Local IP address the client connected to
4672 >lp Local port number the client connected to
f123f5e9 4673 >qos Client connection TOS/DSCP value set by Squid
244da4ad 4674 >nfmark Client connection netfilter packet MARK set by Squid
8652f8e7 4675
a120b7a8
CT
4676 transport::>connection_id Identifies a transport connection
4677 accepted by Squid (e.g., a connection carrying the
4678 logged HTTP request). Currently, Squid only supports
4679 TCP transport connections.
4680
4681 The logged identifier is an unsigned integer. These
4682 IDs are guaranteed to monotonically increase within a
4683 single worker process lifetime, with higher values
4684 corresponding to connections that were accepted later.
4685 Many IDs are skipped (i.e. never logged). Concurrent
4686 workers and restarted workers use similar, partially
4687 overlapping sequences of IDs.
4688
28417506
CT
4689 la Local listening IP address the client connection was connected to.
4690 lp Local listening port number the client connection was connected to.
4691
8652f8e7
AJ
4692 <a Server IP address of the last server or peer connection
4693 <A Server FQDN or peer name
4694 <p Server port number of the last server or peer connection
c3a082ae 4695 <la Local IP address of the last server or peer connection
152e24b3 4696 <lp Local port number of the last server or peer connection
f123f5e9 4697 <qos Server connection TOS/DSCP value set by Squid
244da4ad 4698 <nfmark Server connection netfilter packet MARK set by Squid
f4b68e1a 4699
6131103b
CT
4700 >handshake Raw client handshake
4701 Initial client bytes received by Squid on a newly
4702 accepted TCP connection or inside a just established
4703 CONNECT tunnel. Squid stops accumulating handshake
4704 bytes as soon as the handshake parser succeeds or
4705 fails (determining whether the client is using the
4706 expected protocol).
4707
4708 For HTTP clients, the handshake is the request line.
4709 For TLS clients, the handshake consists of all TLS
4710 records up to and including the TLS record that
4711 contains the last byte of the first ClientHello
4712 message. For clients using an unsupported protocol,
4713 this field contains the bytes received by Squid at the
4714 time of the handshake parsing failure.
4715
4716 See the on_unsupported_protocol directive for more
4717 information on Squid handshake traffic expectations.
4718
4719 Current support is limited to these contexts:
4720 - http_port connections, but only when the
4721 on_unsupported_protocol directive is in use.
4722 - https_port connections (and CONNECT tunnels) that
4723 are subject to the ssl_bump peek or stare action.
4724
4725 To protect binary handshake data, this field is always
4726 base64-encoded (RFC 4648 Section 4). If logformat
4727 field encoding is configured, that encoding is applied
4728 on top of base64. Otherwise, the computed base64 value
4729 is recorded as is.
4730
f4b68e1a
AJ
4731 Time related format codes:
4732
41bd17a4 4733 ts Seconds since epoch
4734 tu subsecond time (milliseconds)
4735 tl Local time. Optional strftime format argument
3ff65596 4736 default %d/%b/%Y:%H:%M:%S %z
41bd17a4 4737 tg GMT time. Optional strftime format argument
3ff65596 4738 default %d/%b/%Y:%H:%M:%S %z
41bd17a4 4739 tr Response time (milliseconds)
3ff65596 4740 dt Total time spent making DNS lookups (milliseconds)
9603207d 4741 tS Approximate master transaction start time in
af0ded40
CT
4742 <full seconds since epoch>.<fractional seconds> format.
4743 Currently, Squid considers the master transaction
4744 started when a complete HTTP request header initiating
4745 the transaction is received from the client. This is
4746 the same value that Squid uses to calculate transaction
4747 response time when logging %tr to access.log. Currently,
4748 Squid uses millisecond resolution for %tS values,
4749 similar to the default access.log "current time" field
4750 (%ts.%03tu).
3ff65596 4751
8652f8e7
AJ
4752 Access Control related format codes:
4753
4754 et Tag returned by external acl
4755 ea Log string returned by external acl
4756 un User name (any available)
4757 ul User name from authentication
4758 ue User name from external acl helper
4759 ui User name from ident
50b5c983
AJ
4760 un A user name. Expands to the first available name
4761 from the following list of information sources:
4762 - authenticated user name, like %ul
4763 - user name supplied by an external ACL, like %ue
4764 - SSL client name, like %us
4765 - ident user name, like %ui
d4806c91
CT
4766 credentials Client credentials. The exact meaning depends on
4767 the authentication scheme: For Basic authentication,
4768 it is the password; for Digest, the realm sent by the
4769 client; for NTLM and Negotiate, the client challenge
4770 or client credentials prefixed with "YR " or "KK ".
8652f8e7
AJ
4771
4772 HTTP related format codes:
3ff65596 4773
d6df21d2
AJ
4774 REQUEST
4775
4776 [http::]rm Request method (GET/POST etc)
4777 [http::]>rm Request method from client
4778 [http::]<rm Request method sent to server or peer
bec110e4
EB
4779
4780 [http::]ru Request URL received (or computed) and sanitized
4781
4782 Logs request URI received from the client, a
4783 request adaptation service, or a request
4784 redirector (whichever was applied last).
4785
4786 Computed URLs are URIs of internally generated
4787 requests and various "error:..." URIs.
4788
4789 Honors strip_query_terms and uri_whitespace.
4790
4791 This field is not encoded by default. Encoding
4792 this field using variants of %-encoding will
4793 clash with uri_whitespace modifications that
4794 also use %-encoding.
4795
4796 [http::]>ru Request URL received from the client (or computed)
4797
4798 Computed URLs are URIs of internally generated
4799 requests and various "error:..." URIs.
4800
4801 Unlike %ru, this request URI is not affected
4802 by request adaptation, URL rewriting services,
4803 and strip_query_terms.
4804
4805 Honors uri_whitespace.
4806
4807 This field is using pass-through URL encoding
4808 by default. Encoding this field using other
4809 variants of %-encoding will clash with
4810 uri_whitespace modifications that also use
4811 %-encoding.
4812
d6df21d2 4813 [http::]<ru Request URL sent to server or peer
5aca9cf2
AJ
4814 [http::]>rs Request URL scheme from client
4815 [http::]<rs Request URL scheme sent to server or peer
fa450988 4816 [http::]>rd Request URL domain from client
f42ac6e6 4817 [http::]<rd Request URL domain sent to server or peer
5aca9cf2
AJ
4818 [http::]>rP Request URL port from client
4819 [http::]<rP Request URL port sent to server or peer
4820 [http::]rp Request URL path excluding hostname
4821 [http::]>rp Request URL path excluding hostname from client
4822 [http::]<rp Request URL path excluding hostname sent to server or peer
d6df21d2
AJ
4823 [http::]rv Request protocol version
4824 [http::]>rv Request protocol version from client
4825 [http::]<rv Request protocol version sent to server or peer
4826
5aca9cf2 4827 [http::]>h Original received request header.
19483c50
AR
4828 Usually differs from the request header sent by
4829 Squid, although most fields are often preserved.
4830 Accepts optional header field name/value filter
4831 argument using name[:[separator]element] format.
4832 [http::]>ha Received request header after adaptation and
4833 redirection (pre-cache REQMOD vectoring point).
4834 Usually differs from the request header sent by
4835 Squid, although most fields are often preserved.
6fca33e0 4836 Optional header name argument as for >h
d6df21d2 4837
d6df21d2
AJ
4838 RESPONSE
4839
4840 [http::]<Hs HTTP status code received from the next hop
4841 [http::]>Hs HTTP status code sent to the client
4842
3ff65596
AR
4843 [http::]<h Reply header. Optional header name argument
4844 as for >h
d6df21d2
AJ
4845
4846 [http::]mt MIME content type
4847
4848
4849 SIZE COUNTERS
4850
4851 [http::]st Total size of request + reply traffic with client
4852 [http::]>st Total size of request received from client.
4853 Excluding chunked encoding bytes.
4854 [http::]<st Total size of reply sent to client (after adaptation)
4855
4856 [http::]>sh Size of request headers received from client
4857 [http::]<sh Size of reply headers sent to client (after adaptation)
4858
4859 [http::]<sH Reply high offset sent
4860 [http::]<sS Upstream object size
4861
9603207d 4862 [http::]<bs Number of HTTP-equivalent message body bytes
bae917ac
CT
4863 received from the next hop, excluding chunked
4864 transfer encoding and control messages.
6ea12e8f 4865 Generated FTP listings are treated as
bae917ac 4866 received bodies.
d6df21d2 4867
d6df21d2
AJ
4868 TIMING
4869
3ff65596
AR
4870 [http::]<pt Peer response time in milliseconds. The timer starts
4871 when the last request byte is sent to the next hop
4872 and stops when the last response byte is received.
9603207d 4873 [http::]<tt Total time in milliseconds. The timer
3ff65596
AR
4874 starts with the first connect request (or write I/O)
4875 sent to the first selected peer. The timer stops
4876 with the last I/O with the last peer.
4877
8652f8e7
AJ
4878 Squid handling related format codes:
4879
4880 Ss Squid request status (TCP_MISS etc)
4881 Sh Squid hierarchy status (DEFAULT_PARENT etc)
4882
08097970
AR
4883 SSL-related format codes:
4884
4885 ssl::bump_mode SslBump decision for the transaction:
4886
4887 For CONNECT requests that initiated bumping of
4888 a connection and for any request received on
4889 an already bumped connection, Squid logs the
bf352fb2
CT
4890 corresponding SslBump mode ("splice", "bump",
4891 "peek", "stare", "terminate", "server-first"
9603207d 4892 or "client-first"). See the ssl_bump option
bf352fb2 4893 for more information about these modes.
08097970
AR
4894
4895 A "none" token is logged for requests that
4896 triggered "ssl_bump" ACL evaluation matching
bf352fb2 4897 a "none" rule.
08097970
AR
4898
4899 In all other cases, a single dash ("-") is
4900 logged.
4901
4f6990ec 4902 ssl::>sni SSL client SNI sent to Squid.
cedca6e7 4903
c28b9a0e
AJ
4904 ssl::>cert_subject
4905 The Subject field of the received client
4906 SSL certificate or a dash ('-') if Squid has
4907 received an invalid/malformed certificate or
4908 no certificate at all. Consider encoding the
4909 logged value because Subject often has spaces.
4910
4911 ssl::>cert_issuer
4912 The Issuer field of the received client
4913 SSL certificate or a dash ('-') if Squid has
4914 received an invalid/malformed certificate or
4915 no certificate at all. Consider encoding the
4916 logged value because Issuer often has spaces.
4917
e2e33acc
CT
4918 ssl::<cert_subject
4919 The Subject field of the received server
4920 TLS certificate or a dash ('-') if this is
4921 not available. Consider encoding the logged
4922 value because Subject often has spaces.
4923
8f1c6091 4924 ssl::<cert_issuer
e2e33acc
CT
4925 The Issuer field of the received server
4926 TLS certificate or a dash ('-') if this is
4927 not available. Consider encoding the logged
4928 value because Issuer often has spaces.
4929
12b5040f
DN
4930 ssl::<cert
4931 The received server x509 certificate in PEM
4932 format, including BEGIN and END lines (or a
4933 dash ('-') if the certificate is unavailable).
4934
4935 WARNING: Large certificates will exceed the
4936 current 8KB access.log record limit, resulting
4937 in truncated records. Such truncation usually
4938 happens in the middle of a record field. The
4939 limit applies to all access logging modules.
4940
4941 The logged certificate may have failed
4942 validation and may not be trusted by Squid.
4943 This field does not include any intermediate
4944 certificates that may have been received from
4945 the server or fetched during certificate
4946 validation process.
4947
4948 Currently, Squid only collects server
4949 certificates during step3 of SslBump
4950 processing; connections that were not subject
4951 to ssl_bump rules or that did not match a peek
4952 or stare rule at step2 will not have the
4953 server certificate information.
4954
4955 This field is using pass-through URL encoding
4956 by default.
4957
c28b9a0e
AJ
4958 ssl::<cert_errors
4959 The list of certificate validation errors
4960 detected by Squid (including OpenSSL and
4961 certificate validation helper components). The
4962 errors are listed in the discovery order. By
4963 default, the error codes are separated by ':'.
4964 Accepts an optional separator argument.
4965
2bcab852
CT
4966 %ssl::>negotiated_version The negotiated TLS version of the
4967 client connection.
4968
4969 %ssl::<negotiated_version The negotiated TLS version of the
4970 last server or peer connection.
4971
4972 %ssl::>received_hello_version The TLS version of the Hello
4973 message received from TLS client.
4974
4975 %ssl::<received_hello_version The TLS version of the Hello
4976 message received from TLS server.
4977
4978 %ssl::>received_supported_version The maximum TLS version
4979 supported by the TLS client.
4980
4981 %ssl::<received_supported_version The maximum TLS version
4982 supported by the TLS server.
4983
4984 %ssl::>negotiated_cipher The negotiated cipher of the
4985 client connection.
4986
4987 %ssl::<negotiated_cipher The negotiated cipher of the
4988 last server or peer connection.
4989
5038f9d8 4990 If ICAP is enabled, the following code becomes available (as
3ff65596
AR
4991 well as ICAP log codes documented with the icap_log option):
4992
40dc90df
AR
4993 icap::tt Total ICAP "blocking" time for the HTTP transaction. The
4994 timer ticks while Squid checks adaptation_access and while
4995 ICAP transaction(s) expect ICAP response headers, including
4996 the embedded adapted HTTP message headers (where applicable).
4997 This measurement is meant to estimate ICAP impact on HTTP
4998 transaction response times, but it does not currently account
4999 for slow ICAP response body delivery blocking HTTP progress.
5000
5001 Once Squid receives the final ICAP response headers (e.g.,
5002 ICAP 200 or 204) and the associated adapted HTTP message
5003 headers (if any) from the ICAP service, the corresponding ICAP
5004 transaction stops affecting this measurement, even though the
5005 transaction itself may continue for a long time (e.g., to
5006 finish sending the ICAP request and/or to finish receiving the
5007 ICAP response body).
5008
5009 When "blocking" sections of multiple concurrent ICAP
5010 transactions overlap in time, the overlapping segment is
5011 counted only once.
5012
5013 To see complete ICAP transaction response times (rather than
5014 the cumulative effect of their blocking sections) use the
5015 %adapt::all_trs logformat code or the icap_log directive.
3ff65596 5016
c28b9a0e 5017 If adaptation is enabled the following codes become available:
3ff65596 5018
5038f9d8
AR
5019 adapt::<last_h The header of the last ICAP response or
5020 meta-information from the last eCAP
5021 transaction related to the HTTP transaction.
5022 Like <h, accepts an optional header name
5023 argument.
3ff65596
AR
5024
5025 adapt::sum_trs Summed adaptation transaction response
5026 times recorded as a comma-separated list in
5027 the order of transaction start time. Each time
5028 value is recorded as an integer number,
5029 representing response time of one or more
5030 adaptation (ICAP or eCAP) transaction in
5031 milliseconds. When a failed transaction is
5032 being retried or repeated, its time is not
5033 logged individually but added to the
40dc90df
AR
5034 replacement (next) transaction. Lifetimes of individually
5035 listed adaptation transactions may overlap.
5036 See also: %icap::tt and %adapt::all_trs.
3ff65596
AR
5037
5038 adapt::all_trs All adaptation transaction response times.
40dc90df 5039 Same as %adapt::sum_trs but response times of
3ff65596
AR
5040 individual transactions are never added
5041 together. Instead, all transaction response
5042 times are recorded individually.
5043
5044 You can prefix adapt::*_trs format codes with adaptation
5045 service name in curly braces to record response time(s) specific
5046 to that service. For example: %{my_service}adapt::sum_trs
5473c134 5047
36c774f7
EB
5048 Format codes related to the PROXY protocol:
5049
5050 proxy_protocol::>h PROXY protocol header, including optional TLVs.
5051
5052 Supports the same field and element reporting/extraction logic
5053 as %http::>h. For configuration and reporting purposes, Squid
5054 maps each PROXY TLV to an HTTP header field: the TLV type
5055 (configured as a decimal integer) is the field name, and the
5056 TLV value is the field value. All TLVs of "LOCAL" connections
5057 (in PROXY protocol terminology) are currently skipped/ignored.
5058
5059 Squid also maps the following standard PROXY protocol header
5060 blocks to pseudo HTTP headers (their names use PROXY
5061 terminology and start with a colon, following HTTP tradition
5062 for pseudo headers): :command, :version, :src_addr, :dst_addr,
5063 :src_port, and :dst_port.
5064
5065 Without optional parameters, this logformat code logs
5066 pseudo headers and TLVs.
5067
5068 This format code uses pass-through URL encoding by default.
5069
5070 Example:
5071 # relay custom PROXY TLV #224 to adaptation services
5072 adaptation_meta Client-Foo "%proxy_protocol::>h{224}"
5073
5074 See also: %http::>h
5075
7d9acc3c
AJ
5076 The default formats available (which do not need re-defining) are:
5077
bd85ea1f
AJ
5078logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
5079logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
5080logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
20efa1c2
AJ
5081logformat referrer %ts.%03tu %>a %{Referer}>h %ru
5082logformat useragent %>a [%tl] "%{User-Agent}>h"
5083
8652f8e7
AJ
5084 NOTE: When the log_mime_hdrs directive is set to ON.
5085 The squid, common and combined formats have a safely encoded copy
5086 of the mime headers appended to each line within a pair of brackets.
5087
5088 NOTE: The common and combined formats are not quite true to the Apache definition.
5089 The logs from Squid contain an extra status and hierarchy code appended.
20efa1c2 5090
5473c134 5091DOC_END
5092
41bd17a4 5093NAME: access_log cache_access_log
5094TYPE: access_log
5095LOC: Config.Log.accesslogs
82b7abe3 5096DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
5473c134 5097DOC_START
fb0c2f17 5098 Configures whether and how Squid logs HTTP and ICP transactions.
9603207d 5099 If access logging is enabled, a single line is logged for every
fb0c2f17
NH
5100 matching HTTP or ICP request. The recommended directive formats are:
5101
5102 access_log <module>:<place> [option ...] [acl acl ...]
5103 access_log none [acl acl ...]
5104
5105 The following directive format is accepted but may be deprecated:
82b7abe3 5106 access_log <module>:<place> [<logformat name> [acl acl ...]]
fb0c2f17
NH
5107
5108 In most cases, the first ACL name must not contain the '=' character
5109 and should not be equal to an existing logformat name. You can always
5110 start with an 'all' ACL to work around those restrictions.
9603207d 5111
82b7abe3 5112 Will log to the specified module:place using the specified format (which
41bd17a4 5113 must be defined in a logformat directive) those entries which match
5114 ALL the acl's specified (which must be defined in acl clauses).
82b7abe3 5115 If no acl is specified, all requests will be logged to this destination.
9603207d 5116
fb0c2f17
NH
5117 ===== Available options for the recommended directive format =====
5118
5119 logformat=name Names log line format (either built-in or
5120 defined by a logformat directive). Defaults
5121 to 'squid'.
5122
5123 buffer-size=64KB Defines approximate buffering limit for log
5124 records (see buffered_logs). Squid should not
5125 keep more than the specified size and, hence,
5126 should flush records before the buffer becomes
5127 full to avoid overflows under normal
5128 conditions (the exact flushing algorithm is
5129 module-dependent though). The on-error option
5130 controls overflow handling.
5131
5132 on-error=die|drop Defines action on unrecoverable errors. The
5133 'drop' action ignores (i.e., does not log)
5134 affected log records. The default 'die' action
9603207d 5135 kills the affected worker. The drop action
fb0c2f17
NH
5136 support has not been tested for modules other
5137 than tcp.
5138
efc23871
AJ
5139 rotate=N Specifies the number of log file rotations to
5140 make when you run 'squid -k rotate'. The default
5141 is to obey the logfile_rotate directive. Setting
5142 rotate=0 will disable the file name rotation,
5143 but the log files are still closed and re-opened.
5144 This will enable you to rename the logfiles
5145 yourself just before sending the rotate signal.
5146 Only supported by the stdio module.
5147
82b7abe3 5148 ===== Modules Currently available =====
9603207d 5149
bb7a1781 5150 none Do not log any requests matching these ACL.
82b7abe3 5151 Do not specify Place or logformat name.
9603207d 5152
82b7abe3
AJ
5153 stdio Write each log line to disk immediately at the completion of
5154 each request.
5155 Place: the filename and path to be written.
9603207d 5156
82b7abe3
AJ
5157 daemon Very similar to stdio. But instead of writing to disk the log
5158 line is passed to a daemon helper for asychronous handling instead.
5159 Place: varies depending on the daemon.
9603207d 5160
82b7abe3 5161 log_file_daemon Place: the file name and path to be written.
9603207d 5162
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5163 syslog To log each request via syslog facility.
5164 Place: The syslog facility and priority level for these entries.
5165 Place Format: facility.priority
5473c134 5166
82b7abe3
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5167 where facility could be any of:
5168 authpriv, daemon, local0 ... local7 or user.
5473c134 5169
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5170 And priority could be any of:
5171 err, warning, notice, info, debug.
9603207d 5172
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5173 udp To send each log line as text data to a UDP receiver.
5174 Place: The destination host name or IP and port.
f4fc8610 5175 Place Format: //host:port
df2eec10 5176
2bf4e8fa 5177 tcp To send each log line as text data to a TCP receiver.
fb0c2f17 5178 Lines may be accumulated before sending (see buffered_logs).
2bf4e8fa 5179 Place: The destination host name or IP and port.
f4fc8610 5180 Place Format: //host:port
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5181
5182 Default:
82b7abe3 5183 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
41bd17a4 5184DOC_END
5473c134 5185
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5186NAME: icap_log
5187TYPE: access_log
5188IFDEF: ICAP_CLIENT
5189LOC: Config.Log.icaplogs
5190DEFAULT: none
5191DOC_START
5192 ICAP log files record ICAP transaction summaries, one line per
5193 transaction.
5194
5195 The icap_log option format is:
5196 icap_log <filepath> [<logformat name> [acl acl ...]]
5197 icap_log none [acl acl ...]]
9603207d 5198
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5199 Please see access_log option documentation for details. The two
5200 kinds of logs share the overall configuration approach and many
5201 features.
5202
5203 ICAP processing of a single HTTP message or transaction may
5204 require multiple ICAP transactions. In such cases, multiple
5205 ICAP transaction log lines will correspond to a single access
5206 log line.
5207
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5208 ICAP log supports many access.log logformat %codes. In ICAP context,
5209 HTTP message-related %codes are applied to the HTTP message embedded
5210 in an ICAP message. Logformat "%http::>..." codes are used for HTTP
5211 messages embedded in ICAP requests while "%http::<..." codes are used
5212 for HTTP messages embedded in ICAP responses. For example:
5213
5214 http::>h To-be-adapted HTTP message headers sent by Squid to
5215 the ICAP service. For REQMOD transactions, these are
5216 HTTP request headers. For RESPMOD, these are HTTP
5217 response headers, but Squid currently cannot log them
5218 (i.e., %http::>h will expand to "-" for RESPMOD).
5219
5220 http::<h Adapted HTTP message headers sent by the ICAP
5221 service to Squid (i.e., HTTP request headers in regular
5222 REQMOD; HTTP response headers in RESPMOD and during
5223 request satisfaction in REQMOD).
5224
5225 ICAP OPTIONS transactions do not embed HTTP messages.
5226
5227 Several logformat codes below deal with ICAP message bodies. An ICAP
5228 message body, if any, typically includes a complete HTTP message
5229 (required HTTP headers plus optional HTTP message body). When
5230 computing HTTP message body size for these logformat codes, Squid
5231 either includes or excludes chunked encoding overheads; see
5232 code-specific documentation for details.
5233
5234 For Secure ICAP services, all size-related information is currently
5235 computed before/after TLS encryption/decryption, as if TLS was not
5236 in use at all.
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5237
5238 The following format codes are also available for ICAP logs:
5239
5240 icap::<A ICAP server IP address. Similar to <A.
5241
5242 icap::<service_name ICAP service name from the icap_service
5243 option in Squid configuration file.
5244
5245 icap::ru ICAP Request-URI. Similar to ru.
5246
9603207d 5247 icap::rm ICAP request method (REQMOD, RESPMOD, or
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5248 OPTIONS). Similar to existing rm.
5249
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5250 icap::>st The total size of the ICAP request sent to the ICAP
5251 server (ICAP headers + ICAP body), including chunking
5252 metadata (if any).
3ff65596 5253
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EB
5254 icap::<st The total size of the ICAP response received from the
5255 ICAP server (ICAP headers + ICAP body), including
5256 chunking metadata (if any).
3ff65596 5257
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5258 icap::<bs The size of the ICAP response body received from the
5259 ICAP server, excluding chunking metadata (if any).
bae917ac 5260
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5261 icap::tr Transaction response time (in
5262 milliseconds). The timer starts when
5263 the ICAP transaction is created and
5264 stops when the transaction is completed.
5265 Similar to tr.
5266
5267 icap::tio Transaction I/O time (in milliseconds). The
5268 timer starts when the first ICAP request
5269 byte is scheduled for sending. The timers
5270 stops when the last byte of the ICAP response
5271 is received.
5272
5273 icap::to Transaction outcome: ICAP_ERR* for all
5274 transaction errors, ICAP_OPT for OPTION
5275 transactions, ICAP_ECHO for 204
5276 responses, ICAP_MOD for message
5277 modification, and ICAP_SAT for request
5278 satisfaction. Similar to Ss.
5279
5280 icap::Hs ICAP response status code. Similar to Hs.
5281
5282 icap::>h ICAP request header(s). Similar to >h.
5283
5284 icap::<h ICAP response header(s). Similar to <h.
5285
5286 The default ICAP log format, which can be used without an explicit
5287 definition, is called icap_squid:
5288
bd59d61c 5289logformat icap_squid %ts.%03tu %6icap::tr %>A %icap::to/%03icap::Hs %icap::<st %icap::rm %icap::ru %un -/%icap::<A -
3ff65596 5290
bd59d61c 5291 See also: logformat and %adapt::<last_h
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5292DOC_END
5293
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5294NAME: logfile_daemon
5295TYPE: string
5296DEFAULT: @DEFAULT_LOGFILED@
5297LOC: Log::TheConfig.logfile_daemon
5298DOC_START
5299 Specify the path to the logfile-writing daemon. This daemon is
5300 used to write the access and store logs, if configured.
14b24caf
HN
5301
5302 Squid sends a number of commands to the log daemon:
5303 L<data>\n - logfile data
5304 R\n - rotate file
5305 T\n - truncate file
dd68402f 5306 O\n - reopen file
14b24caf
HN
5307 F\n - flush file
5308 r<n>\n - set rotate count to <n>
5309 b<n>\n - 1 = buffer output, 0 = don't buffer output
5310
5311 No responses is expected.
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AJ
5312DOC_END
5313
8ebad780 5314NAME: stats_collection
3ff65596 5315TYPE: acl_access
8ebad780 5316LOC: Config.accessList.stats_collection
3ff65596 5317DEFAULT: none
638402dd 5318DEFAULT_DOC: Allow logging for all transactions.
5b0f5383 5319COMMENT: allow|deny acl acl...
3ff65596 5320DOC_START
8ebad780
CT
5321 This options allows you to control which requests gets accounted
5322 in performance counters.
b3567eb5
FC
5323
5324 This clause only supports fast acl types.
5325 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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5326DOC_END
5327
41bd17a4 5328NAME: cache_store_log
5329TYPE: string
df2eec10 5330DEFAULT: none
41bd17a4 5331LOC: Config.Log.store
5332DOC_START
5333 Logs the activities of the storage manager. Shows which
5334 objects are ejected from the cache, and which objects are
6d1dfcfc 5335 saved and for how long.
df2eec10 5336 There are not really utilities to analyze this data, so you can safely
6d1dfcfc 5337 disable it (the default).
9603207d 5338
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AJ
5339 Store log uses modular logging outputs. See access_log for the list
5340 of modules supported.
9603207d 5341
e0855596 5342 Example:
6d1dfcfc
AJ
5343 cache_store_log stdio:@DEFAULT_STORE_LOG@
5344 cache_store_log daemon:@DEFAULT_STORE_LOG@
5473c134 5345DOC_END
5346
41bd17a4 5347NAME: cache_swap_state cache_swap_log
5348TYPE: string
5349LOC: Config.Log.swap
5473c134 5350DEFAULT: none
638402dd 5351DEFAULT_DOC: Store the journal inside its cache_dir
5473c134 5352DOC_START
41bd17a4 5353 Location for the cache "swap.state" file. This index file holds
5354 the metadata of objects saved on disk. It is used to rebuild
5355 the cache during startup. Normally this file resides in each
5356 'cache_dir' directory, but you may specify an alternate
5357 pathname here. Note you must give a full filename, not just
5358 a directory. Since this is the index for the whole object
5359 list you CANNOT periodically rotate it!
5473c134 5360
41bd17a4 5361 If %s can be used in the file name it will be replaced with a
5362 a representation of the cache_dir name where each / is replaced
5363 with '.'. This is needed to allow adding/removing cache_dir
5364 lines when cache_swap_log is being used.
5473c134 5365
41bd17a4 5366 If have more than one 'cache_dir', and %s is not used in the name
5367 these swap logs will have names such as:
5473c134 5368
41bd17a4 5369 cache_swap_log.00
5370 cache_swap_log.01
5371 cache_swap_log.02
5473c134 5372
41bd17a4 5373 The numbered extension (which is added automatically)
5374 corresponds to the order of the 'cache_dir' lines in this
5375 configuration file. If you change the order of the 'cache_dir'
5376 lines in this file, these index files will NOT correspond to
5377 the correct 'cache_dir' entry (unless you manually rename
5378 them). We recommend you do NOT use this option. It is
5379 better to keep these index files in each 'cache_dir' directory.
5473c134 5380DOC_END
5381
41bd17a4 5382NAME: logfile_rotate
5383TYPE: int
5384DEFAULT: 10
5385LOC: Config.Log.rotateNumber
5473c134 5386DOC_START
efc23871 5387 Specifies the default number of logfile rotations to make when you
41bd17a4 5388 type 'squid -k rotate'. The default is 10, which will rotate
5389 with extensions 0 through 9. Setting logfile_rotate to 0 will
5390 disable the file name rotation, but the logfiles are still closed
5391 and re-opened. This will enable you to rename the logfiles
5392 yourself just before sending the rotate signal.
5473c134 5393
efc23871
AJ
5394 Note, from Squid-3.1 this option is only a default for cache.log,
5395 that log can be rotated separately by using debug_options.
5396
66f92ffc 5397 Note, from Squid-4 this option is only a default for access.log
efc23871
AJ
5398 recorded by stdio: module. Those logs can be rotated separately by
5399 using the rotate=N option on their access_log directive.
5400
41bd17a4 5401 Note, the 'squid -k rotate' command normally sends a USR1
5402 signal to the running squid process. In certain situations
5403 (e.g. on Linux with Async I/O), USR1 is used for other
5404 purposes, so -k rotate uses another signal. It is best to get
5405 in the habit of using 'squid -k rotate' instead of 'kill -USR1
5406 <pid>'.
62493678 5407
41bd17a4 5408DOC_END
5473c134 5409
41bd17a4 5410NAME: mime_table
5411TYPE: string
5412DEFAULT: @DEFAULT_MIME_TABLE@
5413LOC: Config.mimeTablePathname
5414DOC_START
638402dd
AJ
5415 Path to Squid's icon configuration file.
5416
5417 You shouldn't need to change this, but the default file contains
5418 examples and formatting information if you do.
5473c134 5419DOC_END
5420
41bd17a4 5421NAME: log_mime_hdrs
5422COMMENT: on|off
5423TYPE: onoff
5424LOC: Config.onoff.log_mime_hdrs
5425DEFAULT: off
5426DOC_START
5427 The Cache can record both the request and the response MIME
5428 headers for each HTTP transaction. The headers are encoded
5429 safely and will appear as two bracketed fields at the end of
5430 the access log (for either the native or httpd-emulated log
5431 formats). To enable this logging set log_mime_hdrs to 'on'.
5432DOC_END
5473c134 5433
41bd17a4 5434NAME: pid_filename
5435TYPE: string
5436DEFAULT: @DEFAULT_PID_FILE@
5437LOC: Config.pidFilename
5473c134 5438DOC_START
41bd17a4 5439 A filename to write the process-id to. To disable, enter "none".
5473c134 5440DOC_END
5441
41bd17a4 5442NAME: client_netmask
5443TYPE: address
5444LOC: Config.Addrs.client_netmask
0eb08770 5445DEFAULT: no_addr
638402dd 5446DEFAULT_DOC: Log full client IP address
5473c134 5447DOC_START
41bd17a4 5448 A netmask for client addresses in logfiles and cachemgr output.
5449 Change this to protect the privacy of your cache clients.
5450 A netmask of 255.255.255.0 will log all IP's in that range with
5451 the last digit set to '0'.
5473c134 5452DOC_END
5453
41bd17a4 5454NAME: strip_query_terms
5473c134 5455TYPE: onoff
41bd17a4 5456LOC: Config.onoff.strip_query_terms
5473c134 5457DEFAULT: on
5458DOC_START
41bd17a4 5459 By default, Squid strips query terms from requested URLs before
638402dd
AJ
5460 logging. This protects your user's privacy and reduces log size.
5461
5462 When investigating HIT/MISS or other caching behaviour you
5463 will need to disable this to see the full URL used by Squid.
5473c134 5464DOC_END
5465
41bd17a4 5466NAME: buffered_logs
5467COMMENT: on|off
5468TYPE: onoff
5469DEFAULT: off
5470LOC: Config.onoff.buffered_logs
5473c134 5471DOC_START
638402dd
AJ
5472 Whether to write/send access_log records ASAP or accumulate them and
5473 then write/send them in larger chunks. Buffering may improve
5474 performance because it decreases the number of I/Os. However,
5475 buffering increases the delay before log records become available to
5476 the final recipient (e.g., a disk file or logging daemon) and,
5477 hence, increases the risk of log records loss.
5478
5479 Note that even when buffered_logs are off, Squid may have to buffer
5480 records if it cannot write/send them immediately due to pending I/Os
5481 (e.g., the I/O writing the previous log record) or connectivity loss.
5482
fb0c2f17 5483 Currently honored by 'daemon' and 'tcp' access_log modules only.
6b698a21 5484DOC_END
0976f8db 5485
2b753521 5486NAME: netdb_filename
5487TYPE: string
221faecb 5488DEFAULT: stdio:@DEFAULT_NETDB_FILE@
2b753521 5489LOC: Config.netdbFilename
fb6a61d1 5490IFDEF: USE_ICMP
2b753521 5491DOC_START
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AJ
5492 Where Squid stores it's netdb journal.
5493 When enabled this journal preserves netdb state between restarts.
5494
2b753521 5495 To disable, enter "none".
5496DOC_END
5497
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5498NAME: tls_key_log
5499TYPE: Security::KeyLog*
5500DEFAULT: none
5501LOC: Config.Log.tlsKeys
5502IFDEF: USE_OPENSSL
5503DOC_START
5504 Configures whether and where Squid records pre-master secret and
5505 related encryption details for TLS connections accepted or established
5506 by Squid. These connections include connections accepted at
5507 https_port, TLS connections opened to origin servers/cache_peers/ICAP
5508 services, and TLS tunnels bumped by Squid using the SslBump feature.
5509 This log (a.k.a. SSLKEYLOGFILE) is meant for triage with traffic
5510 inspection tools like Wireshark.
5511
5512 tls_key_log <destination> [options] [if [!]<acl>...]
5513
5514 WARNING: This log allows anybody to decrypt the corresponding
5515 encrypted TLS connections, both in-flight and postmortem.
5516
5517 At most one log file is supported at this time. Repeated tls_key_log
5518 directives are treated as fatal configuration errors. By default, no
5519 log is created or updated.
5520
5521 If the log file does not exist, Squid creates it. Otherwise, Squid
5522 appends an existing log file.
5523
5524 The directive is consulted whenever a TLS connection is accepted or
5525 established by Squid. TLS connections that fail the handshake may be
5526 logged if Squid got enough information to form a log record. A record
5527 is logged only if all of the configured ACLs match.
5528
5529 While transport-related ACLs like src and dst should work, Squid may
5530 not have access to higher-level information. For example, when logging
5531 accepted https_port connections, Squid does not yet have access to the
5532 expected HTTPS request. Similarly, an HTTPS response is not available
5533 when logging most TLS connections established by Squid.
5534
5535 The log record format is meant to be compatible with TLS deciphering
5536 features of Wireshark which relies on fields like CLIENT_RANDOM and
5537 RSA Master-Key. A single log record usually spans multiple lines.
5538 Technical documentation for that format is maintained inside the
5539 Wireshark code (e.g., see tls_keylog_process_lines() comments as of
5540 Wireshark commit e3d44136f0f0026c5e893fa249f458073f3b7328). TLS key
5541 log does not support custom record formats.
5542
5543 This clause only supports fast acl types.
5544 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5545
5546 See access_log's <module>:<place> parameter for a list of supported
5547 logging destinations.
5548
5549 TLS key log supports all access_log key=value options with the
5550 exception of logformat=name.
5551
5552 Requires Squid built with OpenSSL support.
5553DOC_END
5554
5555
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AJ
5556COMMENT_START
5557 OPTIONS FOR TROUBLESHOOTING
5558 -----------------------------------------------------------------------------
5559COMMENT_END
5560
5561NAME: cache_log
5562TYPE: string
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AJ
5563DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
5564LOC: Debug::cache_log
5565DOC_START
638402dd
AJ
5566 Squid administrative logging file.
5567
5568 This is where general information about Squid behavior goes. You can
5569 increase the amount of data logged to this file and how often it is
5570 rotated with "debug_options"
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AJ
5571DOC_END
5572
c59baaa8
EB
5573NAME: cache_log_message
5574TYPE: cache_log_message
5575DEFAULT: none
5576DEFAULT_DOC: Use debug_options.
5577LOC: Config.debugMessages
5578DOC_START
5579 Configures logging of individual cache.log messages.
5580
5581 cache_log_message id=<number> option...
5582 cache_log_message ids=<number>-<number> option...
5583
5584 Most messages have _not_ been instrumented to support this directive
5585 yet. For the list of instrumented messages and their IDs, please see
5586 the doc/debug-messages.txt file.
5587
5588 Message ID corresponds to the message semantics rather than message
5589 text or source code location. The ID is stable across Squid
5590 instances and versions. Substantial changes in message semantics
5591 result in a new ID assignment. To reduce the danger of suppressing
5592 an important log message, the old IDs of removed (or substantially
5593 changed) messages are never reused.
5594
5595 If more than one cache_log_message directive refers to the same
5596 message ID, the last directive wins.
5597
5598 Use ids=min-max syntax to apply the same message configuration to an
5599 inclusive range of message IDs. An ID range with N values has
5600 exactly the same effect as typing N cache_log_message lines.
5601
5602 At least one option is required. Supported options are:
5603
5604 level=<number>: The logging level to use for the message. Squid
5605 command line options (-s and -d) as well as the debug_options
5606 directive control which levels go to syslog, stderr, and/or
5607 cache.log. In most environments, using level=2 or higher stops
5608 Squid from logging the message anywhere. By default, the
5609 hard-coded message-specific level is used.
5610
5611 limit=<number>: After logging the specified number of messages at
5612 the configured (or default) debugging level DL, start using
5613 level 3 (for DL 0 and 1) or 8 (for higher DL values). Usually,
5614 level-3+ messages are not logged anywhere so this option can
5615 often be used to effectively suppress the message. Each SMP
5616 Squid process gets the same limit.
5617DOC_END
5618
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AJ
5619NAME: debug_options
5620TYPE: eol
47df1aa7 5621DEFAULT: ALL,1
638402dd 5622DEFAULT_DOC: Log all critical and important messages.
62493678
AJ
5623LOC: Debug::debugOptions
5624DOC_START
5625 Logging options are set as section,level where each source file
5626 is assigned a unique section. Lower levels result in less
5627 output, Full debugging (level 9) can result in a very large
5628 log file, so be careful.
5629
5630 The magic word "ALL" sets debugging levels for all sections.
638402dd 5631 The default is to run with "ALL,1" to record important warnings.
62493678 5632
47df1aa7
AJ
5633 The rotate=N option can be used to keep more or less of these logs
5634 than would otherwise be kept by logfile_rotate.
62493678
AJ
5635 For most uses a single log should be enough to monitor current
5636 events affecting Squid.
5637DOC_END
5638
5639NAME: coredump_dir
5640TYPE: string
5641LOC: Config.coredump_dir
62493678 5642DEFAULT_IF_NONE: none
638402dd 5643DEFAULT_DOC: Use the directory from where Squid was started.
62493678
AJ
5644DOC_START
5645 By default Squid leaves core files in the directory from where
5646 it was started. If you set 'coredump_dir' to a directory
5647 that exists, Squid will chdir() to that directory at startup
5648 and coredump files will be left there.
5649
321223fe
DC
5650 In addition to changing the directory, the process permissions are updated
5651 to enable process tracing and/or coredump file generation. The details are
5652 OS-specific, but look for prctl(2) PR_SET_DUMPABLE and procctl(2)
5653 PROC_TRACE_CTL documentation as guiding examples.
5654
47f0eaea 5655CONFIG_START
e0855596 5656
62493678
AJ
5657# Leave coredumps in the first cache dir
5658coredump_dir @DEFAULT_SWAP_DIR@
47f0eaea 5659CONFIG_END
62493678
AJ
5660DOC_END
5661
5662
41bd17a4 5663COMMENT_START
5664 OPTIONS FOR FTP GATEWAYING
5665 -----------------------------------------------------------------------------
5666COMMENT_END
5667
5668NAME: ftp_user
5669TYPE: string
5670DEFAULT: Squid@
5671LOC: Config.Ftp.anon_user
6b698a21 5672DOC_START
41bd17a4 5673 If you want the anonymous login password to be more informative
638402dd 5674 (and enable the use of picky FTP servers), set this to something
41bd17a4 5675 reasonable for your domain, like wwwuser@somewhere.net
7f7db318 5676
41bd17a4 5677 The reason why this is domainless by default is the
5678 request can be made on the behalf of a user in any domain,
5679 depending on how the cache is used.
638402dd 5680 Some FTP server also validate the email address is valid
41bd17a4 5681 (for example perl.com).
6b698a21 5682DOC_END
0976f8db 5683
41bd17a4 5684NAME: ftp_passive
5685TYPE: onoff
5686DEFAULT: on
5687LOC: Config.Ftp.passive
6b698a21 5688DOC_START
41bd17a4 5689 If your firewall does not allow Squid to use passive
5690 connections, turn off this option.
a689bd4e 5691
5692 Use of ftp_epsv_all option requires this to be ON.
5693DOC_END
5694
5695NAME: ftp_epsv_all
5696TYPE: onoff
5697DEFAULT: off
5698LOC: Config.Ftp.epsv_all
5699DOC_START
5700 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
5701
5702 NATs may be able to put the connection on a "fast path" through the
5703 translator, as the EPRT command will never be used and therefore,
5704 translation of the data portion of the segments will never be needed.
5705
b3567eb5
FC
5706 When a client only expects to do two-way FTP transfers this may be
5707 useful.
a689bd4e 5708 If squid finds that it must do a three-way FTP transfer after issuing
5709 an EPSV ALL command, the FTP session will fail.
5710
5711 If you have any doubts about this option do not use it.
5712 Squid will nicely attempt all other connection methods.
5713
51ee534d
AJ
5714 Requires ftp_passive to be ON (default) for any effect.
5715DOC_END
5716
5717NAME: ftp_epsv
ddf5aa2b
CT
5718TYPE: ftp_epsv
5719DEFAULT: none
5720LOC: Config.accessList.ftp_epsv
51ee534d
AJ
5721DOC_START
5722 FTP Protocol extensions permit the use of a special "EPSV" command.
5723
5724 NATs may be able to put the connection on a "fast path" through the
b3567eb5 5725 translator using EPSV, as the EPRT command will never be used
9603207d 5726 and therefore, translation of the data portion of the segments
b3567eb5 5727 will never be needed.
51ee534d 5728
ddf5aa2b
CT
5729 EPSV is often required to interoperate with FTP servers on IPv6
5730 networks. On the other hand, it may break some IPv4 servers.
5731
5732 By default, EPSV may try EPSV with any FTP server. To fine tune
5733 that decision, you may restrict EPSV to certain clients or servers
5734 using ACLs:
5735
5736 ftp_epsv allow|deny al1 acl2 ...
5737
5738 WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
51ee534d 5739
ddf5aa2b 5740 Only fast ACLs are supported.
51ee534d 5741 Requires ftp_passive to be ON (default) for any effect.
41bd17a4 5742DOC_END
9e7dbc51 5743
63ee5443
AJ
5744NAME: ftp_eprt
5745TYPE: onoff
5746DEFAULT: on
5747LOC: Config.Ftp.eprt
5748DOC_START
5749 FTP Protocol extensions permit the use of a special "EPRT" command.
5750
5751 This extension provides a protocol neutral alternative to the
5752 IPv4-only PORT command. When supported it enables active FTP data
5753 channels over IPv6 and efficient NAT handling.
5754
5755 Turning this OFF will prevent EPRT being attempted and will skip
5756 straight to using PORT for IPv4 servers.
5757
5758 Some devices are known to not handle this extension correctly and
2f8abb64 5759 may result in crashes. Devices which support EPRT enough to fail
63ee5443
AJ
5760 cleanly will result in Squid attempting PORT anyway. This directive
5761 should only be disabled when EPRT results in device failures.
5762
5763 WARNING: Doing so will convert Squid back to the old behavior with all
5764 the related problems with external NAT devices/layers and IPv4-only FTP.
5765DOC_END
5766
41bd17a4 5767NAME: ftp_sanitycheck
5768TYPE: onoff
5769DEFAULT: on
5770LOC: Config.Ftp.sanitycheck
5771DOC_START
5772 For security and data integrity reasons Squid by default performs
5773 sanity checks of the addresses of FTP data connections ensure the
5774 data connection is to the requested server. If you need to allow
5775 FTP connections to servers using another IP address for the data
5776 connection turn this off.
5777DOC_END
9e7dbc51 5778
41bd17a4 5779NAME: ftp_telnet_protocol
5780TYPE: onoff
5781DEFAULT: on
5782LOC: Config.Ftp.telnet
5783DOC_START
5784 The FTP protocol is officially defined to use the telnet protocol
5785 as transport channel for the control connection. However, many
5786 implementations are broken and does not respect this aspect of
5787 the FTP protocol.
5788
5789 If you have trouble accessing files with ASCII code 255 in the
5790 path or similar problems involving this ASCII code you can
5791 try setting this directive to off. If that helps, report to the
5792 operator of the FTP server in question that their FTP server
5793 is broken and does not follow the FTP standard.
5794DOC_END
5795
5796COMMENT_START
5797 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
5798 -----------------------------------------------------------------------------
5799COMMENT_END
5800
5801NAME: diskd_program
5802TYPE: string
5803DEFAULT: @DEFAULT_DISKD@
5804LOC: Config.Program.diskd
5805DOC_START
5806 Specify the location of the diskd executable.
5807 Note this is only useful if you have compiled in
5808 diskd as one of the store io modules.
5809DOC_END
5810
5811NAME: unlinkd_program
5812IFDEF: USE_UNLINKD
5813TYPE: string
5814DEFAULT: @DEFAULT_UNLINKD@
5815LOC: Config.Program.unlinkd
5816DOC_START
5817 Specify the location of the executable for file deletion process.
5818DOC_END
5819
5820NAME: pinger_program
41bd17a4 5821IFDEF: USE_ICMP
7a9d36e3
AJ
5822TYPE: icmp
5823DEFAULT: @DEFAULT_PINGER@
5824LOC: IcmpCfg
41bd17a4 5825DOC_START
5826 Specify the location of the executable for the pinger process.
5827DOC_END
5828
cc192b50 5829NAME: pinger_enable
5830TYPE: onoff
5831DEFAULT: on
7a9d36e3 5832LOC: IcmpCfg.enable
cc192b50 5833IFDEF: USE_ICMP
5834DOC_START
5835 Control whether the pinger is active at run-time.
b3567eb5
FC
5836 Enables turning ICMP pinger on and off with a simple
5837 squid -k reconfigure.
cc192b50 5838DOC_END
5839
5840
41bd17a4 5841COMMENT_START
5842 OPTIONS FOR URL REWRITING
5843 -----------------------------------------------------------------------------
5844COMMENT_END
5845
5846NAME: url_rewrite_program redirect_program
5847TYPE: wordlist
5848LOC: Config.Program.redirect
5849DEFAULT: none
5850DOC_START
32f90fcf
PSB
5851 The name and command line parameters of an admin-provided executable
5852 for redirecting clients or adjusting/replacing client request URLs.
41bd17a4 5853
32f90fcf
PSB
5854 This helper is consulted after the received request is cleared by
5855 http_access and adapted using eICAP/ICAP services (if any). If the
5856 helper does not redirect the client, Squid checks adapted_http_access
5857 and may consult the cache or forward the request to the next hop.
41bd17a4 5858
5269ec0e 5859
32f90fcf 5860 For each request, the helper gets one line in the following format:
5269ec0e 5861
32f90fcf 5862 [channel-ID <SP>] request-URL [<SP> extras] <NL>
5269ec0e 5863
32f90fcf 5864 Use url_rewrite_extras to configure what Squid sends as 'extras'.
5269ec0e 5865
32f90fcf
PSB
5866
5867 The helper must reply to each query using a single line:
5868
5869 [channel-ID <SP>] result [<SP> kv-pairs] <NL>
5870
5871 The result section must match exactly one of the following outcomes:
5872
5873 OK [status=30N] url="..."
5874
5875 Redirect the client to a URL supplied in the 'url' parameter.
5876 Optional 'status' specifies the status code to send to the
5877 client in Squid's HTTP redirect response. It must be one of
5878 the standard HTTP redirect status codes: 301, 302, 303, 307,
5879 or 308. When no specific status is requested, Squid uses 302.
c71adec1 5880
5269ec0e 5881 OK rewrite-url="..."
32f90fcf
PSB
5882
5883 Replace the current request URL with the one supplied in the
5884 'rewrite-url' parameter. Squid fetches the resource specified
5885 by the new URL and forwards the received response (or its
5886 cached copy) to the client.
5887
5888 WARNING: Avoid rewriting URLs! When possible, redirect the
5889 client using an "OK url=..." helper response instead.
5890 Rewriting URLs may create inconsistent requests and/or break
5891 synchronization between internal client and origin server
5892 states, especially when URLs or other message parts contain
5893 snippets of that state. For example, Squid does not adjust
5894 Location headers and embedded URLs after the helper rewrites
5895 the request URL.
5269ec0e 5896
c2cbbb02 5897 OK
32f90fcf 5898 Keep the client request intact.
c2cbbb02 5899
5269ec0e 5900 ERR
32f90fcf 5901 Keep the client request intact.
5269ec0e 5902
32f90fcf
PSB
5903 BH [message="..."]
5904 A helper problem that should be reported to the Squid admin
5905 via a level-1 cache.log message. The 'message' parameter is
5906 reserved for specifying the log message.
5269ec0e 5907
32f90fcf
PSB
5908 In addition to the kv-pairs mentioned above, Squid also understands
5909 the following optional kv-pairs in URL rewriter responses:
5269ec0e 5910
457857fe
CT
5911 clt_conn_tag=TAG
5912 Associates a TAG with the client TCP connection.
41bd17a4 5913
32f90fcf
PSB
5914 The clt_conn_tag=TAG pair is treated as a regular transaction
5915 annotation for the current request and also annotates future
5916 requests on the same client connection. A helper may update
5917 the TAG during subsequent requests by returning a new kv-pair.
5269ec0e 5918
41bd17a4 5919
32f90fcf
PSB
5920 Helper messages contain the channel-ID part if and only if the
5921 url_rewrite_children directive specifies positive concurrency. As a
5922 channel-ID value, Squid sends a number between 0 and concurrency-1.
5923 The helper must echo back the received channel-ID in its response.
41bd17a4 5924
32f90fcf 5925 By default, Squid does not use a URL rewriter.
41bd17a4 5926DOC_END
5927
5928NAME: url_rewrite_children redirect_children
48d54e4d 5929TYPE: HelperChildConfig
5b708d95 5930DEFAULT: 20 startup=0 idle=1 concurrency=0
41bd17a4 5931LOC: Config.redirectChildren
5932DOC_START
79933cd6
AR
5933 Specifies the maximum number of redirector processes that Squid may
5934 spawn (numberofchildren) and several related options. Using too few of
5935 these helper processes (a.k.a. "helpers") creates request queues.
5936 Using too many helpers wastes your system resources.
5937
5938 Usage: numberofchildren [option]...
5939
48d54e4d
AJ
5940 The startup= and idle= options allow some measure of skew in your
5941 tuning.
9603207d 5942
48d54e4d 5943 startup=
9603207d 5944
48d54e4d
AJ
5945 Sets a minimum of how many processes are to be spawned when Squid
5946 starts or reconfigures. When set to zero the first request will
5947 cause spawning of the first child process to handle it.
9603207d 5948
48d54e4d
AJ
5949 Starting too few will cause an initial slowdown in traffic as Squid
5950 attempts to simultaneously spawn enough processes to cope.
9603207d 5951
48d54e4d 5952 idle=
9603207d 5953
48d54e4d
AJ
5954 Sets a minimum of how many processes Squid is to try and keep available
5955 at all times. When traffic begins to rise above what the existing
5956 processes can handle this many more will be spawned up to the maximum
5957 configured. A minimum setting of 1 is required.
5958
5959 concurrency=
41bd17a4 5960
41bd17a4 5961 The number of requests each redirector helper can handle in
5962 parallel. Defaults to 0 which indicates the redirector
5963 is a old-style single threaded redirector.
6a171502
AJ
5964
5965 When this directive is set to a value >= 1 then the protocol
5966 used to communicate with the helper is modified to include
9bef05b1
AJ
5967 an ID in front of the request/response. The ID from the request
5968 must be echoed back with the response to that request.
6825b101
CT
5969
5970 queue-size=N
5971
79933cd6
AR
5972 Sets the maximum number of queued requests. A request is queued when
5973 no existing child can accept it due to concurrency limit and no new
5974 child can be started due to numberofchildren limit. The default
5975 maximum is zero if url_rewrite_bypass is enabled and
5976 2*numberofchildren otherwise. If the queued requests exceed queue size
5977 and redirector_bypass configuration option is set, then redirector is
5978 bypassed. Otherwise, Squid is allowed to temporarily exceed the
5979 configured maximum, marking the affected helper as "overloaded". If
5980 the helper overload lasts more than 3 minutes, the action prescribed
5981 by the on-persistent-overload option applies.
6082a0e2
EB
5982
5983 on-persistent-overload=action
5984
5985 Specifies Squid reaction to a new helper request arriving when the helper
5986 has been overloaded for more that 3 minutes already. The number of queued
5987 requests determines whether the helper is overloaded (see the queue-size
5988 option).
5989
5990 Two actions are supported:
5991
5992 die Squid worker quits. This is the default behavior.
5993
5994 ERR Squid treats the helper request as if it was
5995 immediately submitted, and the helper immediately
5996 replied with an ERR response. This action has no effect
5997 on the already queued and in-progress helper requests.
41bd17a4 5998DOC_END
5999
6000NAME: url_rewrite_host_header redirect_rewrites_host_header
6001TYPE: onoff
6002DEFAULT: on
6003LOC: Config.onoff.redir_rewrites_host
6004DOC_START
3ce33807
AJ
6005 To preserve same-origin security policies in browsers and
6006 prevent Host: header forgery by redirectors Squid rewrites
6007 any Host: header in redirected requests.
9603207d 6008
3ce33807
AJ
6009 If you are running an accelerator this may not be a wanted
6010 effect of a redirector. This directive enables you disable
6011 Host: alteration in reverse-proxy traffic.
9603207d 6012
41bd17a4 6013 WARNING: Entries are cached on the result of the URL rewriting
6014 process, so be careful if you have domain-virtual hosts.
9603207d 6015
3ce33807
AJ
6016 WARNING: Squid and other software verifies the URL and Host
6017 are matching, so be careful not to relay through other proxies
6018 or inspecting firewalls with this disabled.
41bd17a4 6019DOC_END
6020
6021NAME: url_rewrite_access redirector_access
6022TYPE: acl_access
6023DEFAULT: none
638402dd 6024DEFAULT_DOC: Allow, unless rules exist in squid.conf.
41bd17a4 6025LOC: Config.accessList.redirector
6026DOC_START
6027 If defined, this access list specifies which requests are
638402dd 6028 sent to the redirector processes.
b3567eb5
FC
6029
6030 This clause supports both fast and slow acl types.
6031 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 6032DOC_END
6033
6034NAME: url_rewrite_bypass redirector_bypass
6035TYPE: onoff
6036LOC: Config.onoff.redirector_bypass
6037DEFAULT: off
6038DOC_START
6039 When this is 'on', a request will not go through the
6082a0e2
EB
6040 redirector if all the helpers are busy. If this is 'off' and the
6041 redirector queue grows too large, the action is prescribed by the
6042 on-persistent-overload option. You should only enable this if the
6043 redirectors are not critical to your caching system. If you use
41bd17a4 6044 redirectors for access control, and you enable this option,
6045 users may have access to pages they should not
6046 be allowed to request.
79933cd6
AR
6047
6048 Enabling this option sets the default url_rewrite_children queue-size
6049 option value to 0.
41bd17a4 6050DOC_END
6051
fe7966ec 6052NAME: url_rewrite_extras
b11724bb
CT
6053TYPE: TokenOrQuotedString
6054LOC: Config.redirector_extras
6055DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
6056DOC_START
6057 Specifies a string to be append to request line format for the
6058 rewriter helper. "Quoted" format values may contain spaces and
6059 logformat %macros. In theory, any logformat %macro can be used.
6060 In practice, a %macro expands as a dash (-) if the helper request is
6061 sent before the required macro information is available to Squid.
6062DOC_END
6063
32fd6d8a 6064NAME: url_rewrite_timeout
ced8def3
AJ
6065TYPE: UrlHelperTimeout
6066LOC: Config.onUrlRewriteTimeout
32fd6d8a
CT
6067DEFAULT: none
6068DEFAULT_DOC: Squid waits for the helper response forever
6069DOC_START
6070 Squid times active requests to redirector. The timeout value and Squid
6071 reaction to a timed out request are configurable using the following
6072 format:
6073
ced8def3 6074 url_rewrite_timeout timeout time-units on_timeout=<action> [response=<quoted-response>]
32fd6d8a
CT
6075
6076 supported timeout actions:
ced8def3 6077 fail Squid return a ERR_GATEWAY_FAILURE error page
32fd6d8a 6078
ced8def3 6079 bypass Do not re-write the URL
32fd6d8a 6080
ced8def3 6081 retry Send the lookup to the helper again
32fd6d8a 6082
ced8def3
AJ
6083 use_configured_response
6084 Use the <quoted-response> as helper response
32fd6d8a
CT
6085DOC_END
6086
a8a0b1c2
EC
6087COMMENT_START
6088 OPTIONS FOR STORE ID
6089 -----------------------------------------------------------------------------
6090COMMENT_END
6091
6092NAME: store_id_program storeurl_rewrite_program
6093TYPE: wordlist
6094LOC: Config.Program.store_id
6095DEFAULT: none
6096DOC_START
6097 Specify the location of the executable StoreID helper to use.
6098 Since they can perform almost any function there isn't one included.
6099
6100 For each requested URL, the helper will receive one line with the format
6101
b11724bb 6102 [channel-ID <SP>] URL [<SP> extras]<NL>
a8a0b1c2
EC
6103
6104
6105 After processing the request the helper must reply using the following format:
6106
6107 [channel-ID <SP>] result [<SP> kv-pairs]
6108
6109 The result code can be:
6110
6111 OK store-id="..."
6112 Use the StoreID supplied in 'store-id='.
6113
6114 ERR
6115 The default is to use HTTP request URL as the store ID.
6116
6117 BH
61beade2 6118 An internal error occurred in the helper, preventing
a8a0b1c2
EC
6119 a result being identified.
6120
457857fe
CT
6121 In addition to the above kv-pairs Squid also understands the following
6122 optional kv-pairs received from URL rewriters:
6123 clt_conn_tag=TAG
6124 Associates a TAG with the client TCP connection.
6125 Please see url_rewrite_program related documentation for this
6126 kv-pair
a8a0b1c2 6127
b11724bb
CT
6128 Helper programs should be prepared to receive and possibly ignore
6129 additional whitespace-separated tokens on each input line.
a8a0b1c2
EC
6130
6131 When using the concurrency= option the protocol is changed by
6132 introducing a query channel tag in front of the request/response.
6133 The query channel tag is a number between 0 and concurrency-1.
6134 This value must be echoed back unchanged to Squid as the first part
6135 of the response relating to its request.
6136
6137 NOTE: when using StoreID refresh_pattern will apply to the StoreID
6138 returned from the helper and not the URL.
6139
6140 WARNING: Wrong StoreID value returned by a careless helper may result
6141 in the wrong cached response returned to the user.
6142
6143 By default, a StoreID helper is not used.
6144DOC_END
6145
fe7966ec 6146NAME: store_id_extras
b11724bb
CT
6147TYPE: TokenOrQuotedString
6148LOC: Config.storeId_extras
6149DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
6150DOC_START
6151 Specifies a string to be append to request line format for the
6152 StoreId helper. "Quoted" format values may contain spaces and
6153 logformat %macros. In theory, any logformat %macro can be used.
6154 In practice, a %macro expands as a dash (-) if the helper request is
6155 sent before the required macro information is available to Squid.
6156DOC_END
6157
a8a0b1c2
EC
6158NAME: store_id_children storeurl_rewrite_children
6159TYPE: HelperChildConfig
6160DEFAULT: 20 startup=0 idle=1 concurrency=0
6161LOC: Config.storeIdChildren
6162DOC_START
79933cd6
AR
6163 Specifies the maximum number of StoreID helper processes that Squid
6164 may spawn (numberofchildren) and several related options. Using
6165 too few of these helper processes (a.k.a. "helpers") creates request
6166 queues. Using too many helpers wastes your system resources.
6167
6168 Usage: numberofchildren [option]...
9603207d 6169
a8a0b1c2
EC
6170 The startup= and idle= options allow some measure of skew in your
6171 tuning.
9603207d 6172
a8a0b1c2 6173 startup=
9603207d 6174
a8a0b1c2
EC
6175 Sets a minimum of how many processes are to be spawned when Squid
6176 starts or reconfigures. When set to zero the first request will
6177 cause spawning of the first child process to handle it.
9603207d 6178
a8a0b1c2
EC
6179 Starting too few will cause an initial slowdown in traffic as Squid
6180 attempts to simultaneously spawn enough processes to cope.
9603207d 6181
a8a0b1c2 6182 idle=
9603207d 6183
a8a0b1c2
EC
6184 Sets a minimum of how many processes Squid is to try and keep available
6185 at all times. When traffic begins to rise above what the existing
6186 processes can handle this many more will be spawned up to the maximum
6187 configured. A minimum setting of 1 is required.
6188
6189 concurrency=
6190
6191 The number of requests each storeID helper can handle in
6192 parallel. Defaults to 0 which indicates the helper
6193 is a old-style single threaded program.
6194
6195 When this directive is set to a value >= 1 then the protocol
6196 used to communicate with the helper is modified to include
6197 an ID in front of the request/response. The ID from the request
6198 must be echoed back with the response to that request.
6825b101
CT
6199
6200 queue-size=N
6201
79933cd6
AR
6202 Sets the maximum number of queued requests to N. A request is queued
6203 when no existing child can accept it due to concurrency limit and no
6204 new child can be started due to numberofchildren limit. The default
6205 maximum is 2*numberofchildren. If the queued requests exceed queue
6206 size and redirector_bypass configuration option is set, then
6207 redirector is bypassed. Otherwise, Squid is allowed to temporarily
6208 exceed the configured maximum, marking the affected helper as
6209 "overloaded". If the helper overload lasts more than 3 minutes, the
6210 action prescribed by the on-persistent-overload option applies.
6082a0e2
EB
6211
6212 on-persistent-overload=action
6213
6214 Specifies Squid reaction to a new helper request arriving when the helper
6215 has been overloaded for more that 3 minutes already. The number of queued
6216 requests determines whether the helper is overloaded (see the queue-size
6217 option).
6218
6219 Two actions are supported:
6220
6221 die Squid worker quits. This is the default behavior.
6222
6223 ERR Squid treats the helper request as if it was
6224 immediately submitted, and the helper immediately
6225 replied with an ERR response. This action has no effect
6226 on the already queued and in-progress helper requests.
a8a0b1c2
EC
6227DOC_END
6228
6229NAME: store_id_access storeurl_rewrite_access
6230TYPE: acl_access
6231DEFAULT: none
638402dd 6232DEFAULT_DOC: Allow, unless rules exist in squid.conf.
a8a0b1c2
EC
6233LOC: Config.accessList.store_id
6234DOC_START
6235 If defined, this access list specifies which requests are
6236 sent to the StoreID processes. By default all requests
6237 are sent.
6238
6239 This clause supports both fast and slow acl types.
6240 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6241DOC_END
6242
6243NAME: store_id_bypass storeurl_rewrite_bypass
6244TYPE: onoff
6245LOC: Config.onoff.store_id_bypass
6246DEFAULT: on
6247DOC_START
6248 When this is 'on', a request will not go through the
6082a0e2
EB
6249 helper if all helpers are busy. If this is 'off' and the helper
6250 queue grows too large, the action is prescribed by the
6251 on-persistent-overload option. You should only enable this if the
6252 helpers are not critical to your caching system. If you use
9603207d 6253 helpers for critical caching components, and you enable this
a8a0b1c2 6254 option, users may not get objects from cache.
6825b101
CT
6255 This options sets default queue-size option of the store_id_children
6256 to 0.
a8a0b1c2
EC
6257DOC_END
6258
41bd17a4 6259COMMENT_START
6260 OPTIONS FOR TUNING THE CACHE
6261 -----------------------------------------------------------------------------
6262COMMENT_END
6263
f04b37d8 6264NAME: cache no_cache
6265TYPE: acl_access
6266DEFAULT: none
70706149 6267DEFAULT_DOC: By default, this directive is unused and has no effect.
f04b37d8 6268LOC: Config.accessList.noCache
41bd17a4 6269DOC_START
70706149
AR
6270 Requests denied by this directive will not be served from the cache
6271 and their responses will not be stored in the cache. This directive
6272 has no effect on other transactions and on already cached responses.
f04b37d8 6273
b3567eb5
FC
6274 This clause supports both fast and slow acl types.
6275 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
70706149
AR
6276
6277 This and the two other similar caching directives listed below are
6278 checked at different transaction processing stages, have different
6279 access to response information, affect different cache operations,
6280 and differ in slow ACLs support:
6281
6282 * cache: Checked before Squid makes a hit/miss determination.
6283 No access to reply information!
6284 Denies both serving a hit and storing a miss.
6285 Supports both fast and slow ACLs.
6286 * send_hit: Checked after a hit was detected.
6287 Has access to reply (hit) information.
6288 Denies serving a hit only.
6289 Supports fast ACLs only.
6290 * store_miss: Checked before storing a cachable miss.
6291 Has access to reply (miss) information.
6292 Denies storing a miss only.
6293 Supports fast ACLs only.
6294
6295 If you are not sure which of the three directives to use, apply the
6296 following decision logic:
6297
6298 * If your ACL(s) are of slow type _and_ need response info, redesign.
6299 Squid does not support that particular combination at this time.
6300 Otherwise:
6301 * If your directive ACL(s) are of slow type, use "cache"; and/or
6302 * if your directive ACL(s) need no response info, use "cache".
6303 Otherwise:
6304 * If you do not want the response cached, use store_miss; and/or
6305 * if you do not want a hit on a cached response, use send_hit.
6306DOC_END
6307
6308NAME: send_hit
6309TYPE: acl_access
6310DEFAULT: none
6311DEFAULT_DOC: By default, this directive is unused and has no effect.
6312LOC: Config.accessList.sendHit
6313DOC_START
6314 Responses denied by this directive will not be served from the cache
6315 (but may still be cached, see store_miss). This directive has no
6316 effect on the responses it allows and on the cached objects.
6317
6318 Please see the "cache" directive for a summary of differences among
6319 store_miss, send_hit, and cache directives.
6320
6321 Unlike the "cache" directive, send_hit only supports fast acl
6322 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6323
6324 For example:
6325
6326 # apply custom Store ID mapping to some URLs
6327 acl MapMe dstdomain .c.example.com
6328 store_id_program ...
6329 store_id_access allow MapMe
6330
6331 # but prevent caching of special responses
6332 # such as 302 redirects that cause StoreID loops
6333 acl Ordinary http_status 200-299
6334 store_miss deny MapMe !Ordinary
6335
6336 # and do not serve any previously stored special responses
6337 # from the cache (in case they were already cached before
6338 # the above store_miss rule was in effect).
6339 send_hit deny MapMe !Ordinary
6340DOC_END
6341
6342NAME: store_miss
6343TYPE: acl_access
6344DEFAULT: none
6345DEFAULT_DOC: By default, this directive is unused and has no effect.
6346LOC: Config.accessList.storeMiss
6347DOC_START
6348 Responses denied by this directive will not be cached (but may still
6349 be served from the cache, see send_hit). This directive has no
6350 effect on the responses it allows and on the already cached responses.
6351
6352 Please see the "cache" directive for a summary of differences among
6353 store_miss, send_hit, and cache directives. See the
6354 send_hit directive for a usage example.
6355
6356 Unlike the "cache" directive, store_miss only supports fast acl
6357 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 6358DOC_END
6359
570d3f75
AJ
6360NAME: max_stale
6361COMMENT: time-units
6362TYPE: time_t
6363LOC: Config.maxStale
6364DEFAULT: 1 week
6365DOC_START
6366 This option puts an upper limit on how stale content Squid
6367 will serve from the cache if cache validation fails.
2f8abb64 6368 Can be overridden by the refresh_pattern max-stale option.
570d3f75
AJ
6369DOC_END
6370
41bd17a4 6371NAME: refresh_pattern
6372TYPE: refreshpattern
6373LOC: Config.Refresh
6374DEFAULT: none
6375DOC_START
6376 usage: refresh_pattern [-i] regex min percent max [options]
9e7dbc51 6377
6b698a21 6378 By default, regular expressions are CASE-SENSITIVE. To make
6379 them case-insensitive, use the -i option.
9e7dbc51 6380
41bd17a4 6381 'Min' is the time (in minutes) an object without an explicit
6382 expiry time should be considered fresh. The recommended
6383 value is 0, any higher values may cause dynamic applications
6384 to be erroneously cached unless the application designer
6385 has taken the appropriate actions.
9e7dbc51 6386
41bd17a4 6387 'Percent' is a percentage of the objects age (time since last
6388 modification age) an object without explicit expiry time
6389 will be considered fresh.
5b807763 6390
41bd17a4 6391 'Max' is an upper limit on how long objects without an explicit
6d612a9d
GD
6392 expiry time will be considered fresh. The value is also used
6393 to form Cache-Control: max-age header for a request sent from
6394 Squid to origin/parent.
9e7dbc51 6395
41bd17a4 6396 options: override-expire
6397 override-lastmod
6398 reload-into-ims
6399 ignore-reload
41bd17a4 6400 ignore-no-store
6401 ignore-private
570d3f75 6402 max-stale=NN
41bd17a4 6403 refresh-ims
3d8b6ba4 6404 store-stale
a0ec9f68 6405
41bd17a4 6406 override-expire enforces min age even if the server
9b2ad080
HN
6407 sent an explicit expiry time (e.g., with the
6408 Expires: header or Cache-Control: max-age). Doing this
6409 VIOLATES the HTTP standard. Enabling this feature
6410 could make you liable for problems which it causes.
6468fe10 6411
04925576
AJ
6412 Note: override-expire does not enforce staleness - it only extends
6413 freshness / min. If the server returns a Expires time which
6414 is longer than your max time, Squid will still consider
6415 the object fresh for that period of time.
6416
41bd17a4 6417 override-lastmod enforces min age even on objects
6418 that were modified recently.
934b03fc 6419
46017fdd
CT
6420 reload-into-ims changes a client no-cache or ``reload''
6421 request for a cached entry into a conditional request using
6422 If-Modified-Since and/or If-None-Match headers, provided the
6423 cached entry has a Last-Modified and/or a strong ETag header.
6424 Doing this VIOLATES the HTTP standard. Enabling this feature
6425 could make you liable for problems which it causes.
dba79ac5 6426
41bd17a4 6427 ignore-reload ignores a client no-cache or ``reload''
6428 header. Doing this VIOLATES the HTTP standard. Enabling
6429 this feature could make you liable for problems which
6430 it causes.
9bc73deb 6431
41bd17a4 6432 ignore-no-store ignores any ``Cache-control: no-store''
6433 headers received from a server. Doing this VIOLATES
6434 the HTTP standard. Enabling this feature could make you
6435 liable for problems which it causes.
6436
6437 ignore-private ignores any ``Cache-control: private''
6438 headers received from a server. Doing this VIOLATES
6439 the HTTP standard. Enabling this feature could make you
6440 liable for problems which it causes.
6441
41bd17a4 6442 refresh-ims causes squid to contact the origin server
6443 when a client issues an If-Modified-Since request. This
6444 ensures that the client will receive an updated version
6445 if one is available.
6446
9603207d 6447 store-stale stores responses even if they don't have explicit
6448 freshness or a validator (i.e., Last-Modified or an ETag)
6449 present, or if they're already stale. By default, Squid will
3d8b6ba4
AJ
6450 not cache such responses because they usually can't be
6451 reused. Note that such responses will be stale by default.
6452
570d3f75
AJ
6453 max-stale=NN provide a maximum staleness factor. Squid won't
6454 serve objects more stale than this even if it failed to
6455 validate the object. Default: use the max_stale global limit.
6456
41bd17a4 6457 Basically a cached object is:
6458
fb41bbb2 6459 FRESH if expire > now, else STALE
41bd17a4 6460 STALE if age > max
6461 FRESH if lm-factor < percent, else STALE
6462 FRESH if age < min
6463 else STALE
6464
6465 The refresh_pattern lines are checked in the order listed here.
6466 The first entry which matches is used. If none of the entries
6467 match the default will be used.
6468
6469 Note, you must uncomment all the default lines if you want
6470 to change one. The default setting is only active if none is
6471 used.
6472
47f0eaea 6473CONFIG_START
e0855596 6474
638402dd 6475#
e0855596 6476# Add any of your own refresh_pattern entries above these.
638402dd 6477#
41bd17a4 6478refresh_pattern ^ftp: 1440 20% 10080
89db45fa 6479refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
41bd17a4 6480refresh_pattern . 0 20% 4320
47f0eaea 6481CONFIG_END
41bd17a4 6482DOC_END
6483
6484NAME: quick_abort_min
6485COMMENT: (KB)
6486TYPE: kb_int64_t
6487DEFAULT: 16 KB
6488LOC: Config.quickAbort.min
6489DOC_NONE
6490
6491NAME: quick_abort_max
6492COMMENT: (KB)
6493TYPE: kb_int64_t
6494DEFAULT: 16 KB
6495LOC: Config.quickAbort.max
6496DOC_NONE
6497
6498NAME: quick_abort_pct
6499COMMENT: (percent)
6500TYPE: int
6501DEFAULT: 95
6502LOC: Config.quickAbort.pct
6503DOC_START
6504 The cache by default continues downloading aborted requests
6505 which are almost completed (less than 16 KB remaining). This
6506 may be undesirable on slow (e.g. SLIP) links and/or very busy
6507 caches. Impatient users may tie up file descriptors and
6508 bandwidth by repeatedly requesting and immediately aborting
6509 downloads.
6510
6511 When the user aborts a request, Squid will check the
2d4eefd9 6512 quick_abort values to the amount of data transferred until
41bd17a4 6513 then.
6514
6515 If the transfer has less than 'quick_abort_min' KB remaining,
6516 it will finish the retrieval.
6517
6518 If the transfer has more than 'quick_abort_max' KB remaining,
6519 it will abort the retrieval.
6520
6521 If more than 'quick_abort_pct' of the transfer has completed,
6522 it will finish the retrieval.
6523
6524 If you do not want any retrieval to continue after the client
6525 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
6526 to '0 KB'.
6527
6528 If you want retrievals to always continue if they are being
6529 cached set 'quick_abort_min' to '-1 KB'.
6530DOC_END
60d096f4 6531
41bd17a4 6532NAME: read_ahead_gap
6533COMMENT: buffer-size
6534TYPE: b_int64_t
6535LOC: Config.readAheadGap
6536DEFAULT: 16 KB
6537DOC_START
6538 The amount of data the cache will buffer ahead of what has been
6539 sent to the client when retrieving an object from another server.
6540DOC_END
53e738c6 6541
41bd17a4 6542NAME: negative_ttl
626096be 6543IFDEF: USE_HTTP_VIOLATIONS
41bd17a4 6544COMMENT: time-units
6545TYPE: time_t
6546LOC: Config.negativeTtl
ac9cc053 6547DEFAULT: 0 seconds
41bd17a4 6548DOC_START
ac9cc053
AJ
6549 Set the Default Time-to-Live (TTL) for failed requests.
6550 Certain types of failures (such as "connection refused" and
6551 "404 Not Found") are able to be negatively-cached for a short time.
6552 Modern web servers should provide Expires: header, however if they
6553 do not this can provide a minimum TTL.
6554 The default is not to cache errors with unknown expiry details.
6555
6556 Note that this is different from negative caching of DNS lookups.
39956c7c
AJ
6557
6558 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6559 this feature could make you liable for problems which it
6560 causes.
41bd17a4 6561DOC_END
53e738c6 6562
41bd17a4 6563NAME: positive_dns_ttl
6564COMMENT: time-units
6565TYPE: time_t
6566LOC: Config.positiveDnsTtl
6567DEFAULT: 6 hours
6568DOC_START
6569 Upper limit on how long Squid will cache positive DNS responses.
6570 Default is 6 hours (360 minutes). This directive must be set
6571 larger than negative_dns_ttl.
6572DOC_END
c4ab8329 6573
41bd17a4 6574NAME: negative_dns_ttl
6575COMMENT: time-units
6576TYPE: time_t
6577LOC: Config.negativeDnsTtl
6578DEFAULT: 1 minutes
6579DOC_START
6580 Time-to-Live (TTL) for negative caching of failed DNS lookups.
6581 This also sets the lower cache limit on positive lookups.
6582 Minimum value is 1 second, and it is not recommendable to go
6583 much below 10 seconds.
6584DOC_END
7df0bfd7 6585
41bd17a4 6586NAME: range_offset_limit
11e3fa1c
AJ
6587COMMENT: size [acl acl...]
6588TYPE: acl_b_size_t
41bd17a4 6589LOC: Config.rangeOffsetLimit
11e3fa1c 6590DEFAULT: none
41bd17a4 6591DOC_START
11e3fa1c 6592 usage: (size) [units] [[!]aclname]
9603207d 6593
6594 Sets an upper limit on how far (number of bytes) into the file
6595 a Range request may be to cause Squid to prefetch the whole file.
6596 If beyond this limit, Squid forwards the Range request as it is and
11e3fa1c 6597 the result is NOT cached.
9603207d 6598
41bd17a4 6599 This is to stop a far ahead range request (lets say start at 17MB)
6600 from making Squid fetch the whole object up to that point before
6601 sending anything to the client.
9603207d 6602
6603 Multiple range_offset_limit lines may be specified, and they will
6604 be searched from top to bottom on each request until a match is found.
6605 The first match found will be used. If no line matches a request, the
11e3fa1c 6606 default limit of 0 bytes will be used.
9603207d 6607
11e3fa1c 6608 'size' is the limit specified as a number of units.
9603207d 6609
11e3fa1c
AJ
6610 'units' specifies whether to use bytes, KB, MB, etc.
6611 If no units are specified bytes are assumed.
9603207d 6612
11e3fa1c 6613 A size of 0 causes Squid to never fetch more than the
ab275c7b 6614 client requested. (default)
9603207d 6615
11e3fa1c 6616 A size of 'none' causes Squid to always fetch the object from the
41bd17a4 6617 beginning so it may cache the result. (2.0 style)
9603207d 6618
11e3fa1c 6619 'aclname' is the name of a defined ACL.
9603207d 6620
6621 NP: Using 'none' as the byte value here will override any quick_abort settings
11e3fa1c 6622 that may otherwise apply to the range request. The range request will
ab275c7b
AJ
6623 be fully fetched from start to finish regardless of the client
6624 actions. This affects bandwidth usage.
41bd17a4 6625DOC_END
d95b862f 6626
41bd17a4 6627NAME: minimum_expiry_time
6628COMMENT: (seconds)
6629TYPE: time_t
6630LOC: Config.minimum_expiry_time
6631DEFAULT: 60 seconds
6632DOC_START
6633 The minimum caching time according to (Expires - Date)
638402dd
AJ
6634 headers Squid honors if the object can't be revalidated.
6635 The default is 60 seconds.
6636
6637 In reverse proxy environments it might be desirable to honor
6638 shorter object lifetimes. It is most likely better to make
6639 your server return a meaningful Last-Modified header however.
6640
6641 In ESI environments where page fragments often have short
6642 lifetimes, this will often be best set to 0.
41bd17a4 6643DOC_END
c68e9c6b 6644
41bd17a4 6645NAME: store_avg_object_size
58d5c5dd
DK
6646COMMENT: (bytes)
6647TYPE: b_int64_t
41bd17a4 6648DEFAULT: 13 KB
6649LOC: Config.Store.avgObjectSize
6650DOC_START
6651 Average object size, used to estimate number of objects your
6652 cache can hold. The default is 13 KB.
638402dd
AJ
6653
6654 This is used to pre-seed the cache index memory allocation to
6655 reduce expensive reallocate operations while handling clients
6656 traffic. Too-large values may result in memory allocation during
6657 peak traffic, too-small values will result in wasted memory.
6658
6659 Check the cache manager 'info' report metrics for the real
6660 object sizes seen by your Squid before tuning this.
cccac0a2 6661DOC_END
6662
41bd17a4 6663NAME: store_objects_per_bucket
6664TYPE: int
6665DEFAULT: 20
6666LOC: Config.Store.objectsPerBucket
6667DOC_START
6668 Target number of objects per bucket in the store hash table.
6669 Lowering this value increases the total number of buckets and
6670 also the storage maintenance rate. The default is 20.
6671DOC_END
6672
6673COMMENT_START
6674 HTTP OPTIONS
6675 -----------------------------------------------------------------------------
6676COMMENT_END
6677
f04b37d8 6678NAME: request_header_max_size
6679COMMENT: (KB)
6680TYPE: b_size_t
df2eec10 6681DEFAULT: 64 KB
f04b37d8 6682LOC: Config.maxRequestHeaderSize
6683DOC_START
6684 This specifies the maximum size for HTTP headers in a request.
6685 Request headers are usually relatively small (about 512 bytes).
6686 Placing a limit on the request header size will catch certain
6687 bugs (for example with persistent connections) and possibly
6688 buffer-overflow or denial-of-service attacks.
6689DOC_END
6690
6691NAME: reply_header_max_size
6692COMMENT: (KB)
6693TYPE: b_size_t
df2eec10 6694DEFAULT: 64 KB
f04b37d8 6695LOC: Config.maxReplyHeaderSize
6696DOC_START
6697 This specifies the maximum size for HTTP headers in a reply.
6698 Reply headers are usually relatively small (about 512 bytes).
6699 Placing a limit on the reply header size will catch certain
6700 bugs (for example with persistent connections) and possibly
6701 buffer-overflow or denial-of-service attacks.
6702DOC_END
6703
6704NAME: request_body_max_size
6705COMMENT: (bytes)
6706TYPE: b_int64_t
6707DEFAULT: 0 KB
638402dd 6708DEFAULT_DOC: No limit.
f04b37d8 6709LOC: Config.maxRequestBodySize
6710DOC_START
6711 This specifies the maximum size for an HTTP request body.
6712 In other words, the maximum size of a PUT/POST request.
6713 A user who attempts to send a request with a body larger
6714 than this limit receives an "Invalid Request" error message.
6715 If you set this parameter to a zero (the default), there will
6716 be no limit imposed.
638402dd
AJ
6717
6718 See also client_request_buffer_max_size for an alternative
6719 limitation on client uploads which can be configured.
f04b37d8 6720DOC_END
6721
1368d115
CT
6722NAME: client_request_buffer_max_size
6723COMMENT: (bytes)
6724TYPE: b_size_t
6725DEFAULT: 512 KB
6726LOC: Config.maxRequestBufferSize
6727DOC_START
6728 This specifies the maximum buffer size of a client request.
6729 It prevents squid eating too much memory when somebody uploads
6730 a large file.
6731DOC_END
6732
41bd17a4 6733NAME: broken_posts
626096be 6734IFDEF: USE_HTTP_VIOLATIONS
cccac0a2 6735TYPE: acl_access
cccac0a2 6736DEFAULT: none
638402dd 6737DEFAULT_DOC: Obey RFC 2616.
41bd17a4 6738LOC: Config.accessList.brokenPosts
cccac0a2 6739DOC_START
41bd17a4 6740 A list of ACL elements which, if matched, causes Squid to send
6741 an extra CRLF pair after the body of a PUT/POST request.
cccac0a2 6742
41bd17a4 6743 Some HTTP servers has broken implementations of PUT/POST,
6744 and rely on an extra CRLF pair sent by some WWW clients.
cccac0a2 6745
41bd17a4 6746 Quote from RFC2616 section 4.1 on this matter:
cccac0a2 6747
41bd17a4 6748 Note: certain buggy HTTP/1.0 client implementations generate an
6749 extra CRLF's after a POST request. To restate what is explicitly
6750 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
6751 a request with an extra CRLF.
cccac0a2 6752
b3567eb5
FC
6753 This clause only supports fast acl types.
6754 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6755
41bd17a4 6756Example:
6757 acl buggy_server url_regex ^http://....
6758 broken_posts allow buggy_server
6759DOC_END
cccac0a2 6760
22fff3bf 6761NAME: adaptation_uses_indirect_client icap_uses_indirect_client
57d76dd4
AJ
6762COMMENT: on|off
6763TYPE: onoff
22fff3bf 6764IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
57d76dd4 6765DEFAULT: on
22fff3bf 6766LOC: Adaptation::Config::use_indirect_client
57d76dd4 6767DOC_START
ea3ae478
AR
6768 Controls whether the indirect client IP address (instead of the direct
6769 client IP address) is passed to adaptation services.
6770
6771 See also: follow_x_forwarded_for adaptation_send_client_ip
57d76dd4
AJ
6772DOC_END
6773
41bd17a4 6774NAME: via
626096be 6775IFDEF: USE_HTTP_VIOLATIONS
41bd17a4 6776COMMENT: on|off
6777TYPE: onoff
6778DEFAULT: on
6779LOC: Config.onoff.via
6780DOC_START
6781 If set (default), Squid will include a Via header in requests and
6782 replies as required by RFC2616.
6783DOC_END
4cc6eb12 6784
41bd17a4 6785NAME: vary_ignore_expire
6786COMMENT: on|off
6787TYPE: onoff
6788LOC: Config.onoff.vary_ignore_expire
6789DEFAULT: off
6790DOC_START
6791 Many HTTP servers supporting Vary gives such objects
6792 immediate expiry time with no cache-control header
6793 when requested by a HTTP/1.0 client. This option
6794 enables Squid to ignore such expiry times until
6795 HTTP/1.1 is fully implemented.
7e73cd78
AJ
6796
6797 WARNING: If turned on this may eventually cause some
6798 varying objects not intended for caching to get cached.
cccac0a2 6799DOC_END
c4ab8329 6800
41bd17a4 6801NAME: request_header_access
626096be 6802IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6803TYPE: http_header_access
41bd17a4 6804LOC: Config.request_header_access
cccac0a2 6805DEFAULT: none
638402dd 6806DEFAULT_DOC: No limits.
cccac0a2 6807DOC_START
41bd17a4 6808 Usage: request_header_access header_name allow|deny [!]aclname ...
0976f8db 6809
41bd17a4 6810 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6811 this feature could make you liable for problems which it
6812 causes.
0976f8db 6813
41bd17a4 6814 This option replaces the old 'anonymize_headers' and the
6815 older 'http_anonymizer' option with something that is much
3b07476b
CT
6816 more configurable. A list of ACLs for each header name allows
6817 removal of specific header fields under specific conditions.
6818
6819 This option only applies to outgoing HTTP request headers (i.e.,
6820 headers sent by Squid to the next HTTP hop such as a cache peer
6821 or an origin server). The option has no effect during cache hit
6822 detection. The equivalent adaptation vectoring point in ICAP
6823 terminology is post-cache REQMOD.
6824
6825 The option is applied to individual outgoing request header
6826 fields. For each request header field F, Squid uses the first
6827 qualifying sets of request_header_access rules:
6828
6829 1. Rules with header_name equal to F's name.
6830 2. Rules with header_name 'Other', provided F's name is not
6831 on the hard-coded list of commonly used HTTP header names.
6832 3. Rules with header_name 'All'.
6833
6834 Within that qualifying rule set, rule ACLs are checked as usual.
6835 If ACLs of an "allow" rule match, the header field is allowed to
6836 go through as is. If ACLs of a "deny" rule match, the header is
6837 removed and request_header_replace is then checked to identify
6838 if the removed header has a replacement. If no rules within the
6839 set have matching ACLs, the header field is left as is.
5401aa8d 6840
41bd17a4 6841 For example, to achieve the same behavior as the old
6842 'http_anonymizer standard' option, you should use:
5401aa8d 6843
41bd17a4 6844 request_header_access From deny all
6845 request_header_access Referer deny all
41bd17a4 6846 request_header_access User-Agent deny all
5401aa8d 6847
41bd17a4 6848 Or, to reproduce the old 'http_anonymizer paranoid' feature
6849 you should use:
5401aa8d 6850
41bd17a4 6851 request_header_access Authorization allow all
41bd17a4 6852 request_header_access Proxy-Authorization allow all
41bd17a4 6853 request_header_access Cache-Control allow all
41bd17a4 6854 request_header_access Content-Length allow all
6855 request_header_access Content-Type allow all
6856 request_header_access Date allow all
41bd17a4 6857 request_header_access Host allow all
6858 request_header_access If-Modified-Since allow all
41bd17a4 6859 request_header_access Pragma allow all
6860 request_header_access Accept allow all
6861 request_header_access Accept-Charset allow all
6862 request_header_access Accept-Encoding allow all
6863 request_header_access Accept-Language allow all
41bd17a4 6864 request_header_access Connection allow all
41bd17a4 6865 request_header_access All deny all
5401aa8d 6866
638402dd 6867 HTTP reply headers are controlled with the reply_header_access directive.
5401aa8d 6868
638402dd 6869 By default, all headers are allowed (no anonymizing is performed).
5401aa8d 6870DOC_END
6871
41bd17a4 6872NAME: reply_header_access
626096be 6873IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6874TYPE: http_header_access
41bd17a4 6875LOC: Config.reply_header_access
cccac0a2 6876DEFAULT: none
638402dd 6877DEFAULT_DOC: No limits.
cccac0a2 6878DOC_START
41bd17a4 6879 Usage: reply_header_access header_name allow|deny [!]aclname ...
934b03fc 6880
41bd17a4 6881 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6882 this feature could make you liable for problems which it
6883 causes.
934b03fc 6884
41bd17a4 6885 This option only applies to reply headers, i.e., from the
6886 server to the client.
934b03fc 6887
41bd17a4 6888 This is the same as request_header_access, but in the other
3b07476b
CT
6889 direction. Please see request_header_access for detailed
6890 documentation.
cccac0a2 6891
41bd17a4 6892 For example, to achieve the same behavior as the old
6893 'http_anonymizer standard' option, you should use:
cccac0a2 6894
41bd17a4 6895 reply_header_access Server deny all
41bd17a4 6896 reply_header_access WWW-Authenticate deny all
6897 reply_header_access Link deny all
cccac0a2 6898
41bd17a4 6899 Or, to reproduce the old 'http_anonymizer paranoid' feature
6900 you should use:
cccac0a2 6901
41bd17a4 6902 reply_header_access Allow allow all
41bd17a4 6903 reply_header_access WWW-Authenticate allow all
41bd17a4 6904 reply_header_access Proxy-Authenticate allow all
6905 reply_header_access Cache-Control allow all
6906 reply_header_access Content-Encoding allow all
6907 reply_header_access Content-Length allow all
6908 reply_header_access Content-Type allow all
6909 reply_header_access Date allow all
6910 reply_header_access Expires allow all
41bd17a4 6911 reply_header_access Last-Modified allow all
6912 reply_header_access Location allow all
6913 reply_header_access Pragma allow all
41bd17a4 6914 reply_header_access Content-Language allow all
41bd17a4 6915 reply_header_access Retry-After allow all
6916 reply_header_access Title allow all
638402dd 6917 reply_header_access Content-Disposition allow all
41bd17a4 6918 reply_header_access Connection allow all
41bd17a4 6919 reply_header_access All deny all
cccac0a2 6920
638402dd 6921 HTTP request headers are controlled with the request_header_access directive.
cccac0a2 6922
41bd17a4 6923 By default, all headers are allowed (no anonymizing is
6924 performed).
cccac0a2 6925DOC_END
6926
75e4f2ea 6927NAME: request_header_replace header_replace
626096be 6928IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6929TYPE: http_header_replace
41bd17a4 6930LOC: Config.request_header_access
cccac0a2 6931DEFAULT: none
41bd17a4 6932DOC_START
75e4f2ea
MB
6933 Usage: request_header_replace header_name message
6934 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
cccac0a2 6935
41bd17a4 6936 This option allows you to change the contents of headers
75e4f2ea 6937 denied with request_header_access above, by replacing them
638402dd 6938 with some fixed string.
cccac0a2 6939
41bd17a4 6940 This only applies to request headers, not reply headers.
cccac0a2 6941
41bd17a4 6942 By default, headers are removed if denied.
6943DOC_END
cccac0a2 6944
75e4f2ea
MB
6945NAME: reply_header_replace
6946IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6947TYPE: http_header_replace
75e4f2ea
MB
6948LOC: Config.reply_header_access
6949DEFAULT: none
6950DOC_START
6951 Usage: reply_header_replace header_name message
6952 Example: reply_header_replace Server Foo/1.0
6953
6954 This option allows you to change the contents of headers
6955 denied with reply_header_access above, by replacing them
6956 with some fixed string.
6957
6958 This only applies to reply headers, not request headers.
6959
6960 By default, headers are removed if denied.
6961DOC_END
6962
f4698e0b
CT
6963NAME: request_header_add
6964TYPE: HeaderWithAclList
6965LOC: Config.request_header_add
6966DEFAULT: none
6967DOC_START
cde8f31b 6968 Usage: request_header_add field-name field-value [ acl ... ]
f4698e0b
CT
6969 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
6970
6971 This option adds header fields to outgoing HTTP requests (i.e.,
6972 request headers sent by Squid to the next HTTP hop such as a
6973 cache peer or an origin server). The option has no effect during
6974 cache hit detection. The equivalent adaptation vectoring point
6975 in ICAP terminology is post-cache REQMOD.
6976
6977 Field-name is a token specifying an HTTP header name. If a
6978 standard HTTP header name is used, Squid does not check whether
6979 the new header conflicts with any existing headers or violates
6980 HTTP rules. If the request to be modified already contains a
6981 field with the same name, the old field is preserved but the
6982 header field values are not merged.
6983
6984 Field-value is either a token or a quoted string. If quoted
6985 string format is used, then the surrounding quotes are removed
6986 while escape sequences and %macros are processed.
6987
f4698e0b
CT
6988 One or more Squid ACLs may be specified to restrict header
6989 injection to matching requests. As always in squid.conf, all
cde8f31b
NH
6990 ACLs in the ACL list must be satisfied for the insertion to
6991 happen. The request_header_add supports fast ACLs only.
6992
6993 See also: reply_header_add.
6994DOC_END
6995
6996NAME: reply_header_add
6997TYPE: HeaderWithAclList
6998LOC: Config.reply_header_add
6999DEFAULT: none
7000DOC_START
7001 Usage: reply_header_add field-name field-value [ acl ... ]
7002 Example: reply_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
7003
7004 This option adds header fields to outgoing HTTP responses (i.e., response
7005 headers delivered by Squid to the client). This option has no effect on
7006 cache hit detection. The equivalent adaptation vectoring point in
7007 ICAP terminology is post-cache RESPMOD. This option does not apply to
7008 successful CONNECT replies.
7009
7010 Field-name is a token specifying an HTTP header name. If a
7011 standard HTTP header name is used, Squid does not check whether
7012 the new header conflicts with any existing headers or violates
7013 HTTP rules. If the response to be modified already contains a
7014 field with the same name, the old field is preserved but the
7015 header field values are not merged.
7016
7017 Field-value is either a token or a quoted string. If quoted
7018 string format is used, then the surrounding quotes are removed
7019 while escape sequences and %macros are processed.
7020
7021 One or more Squid ACLs may be specified to restrict header
7022 injection to matching responses. As always in squid.conf, all
7023 ACLs in the ACL list must be satisfied for the insertion to
7024 happen. The reply_header_add option supports fast ACLs only.
7025
7026 See also: request_header_add.
f4698e0b
CT
7027DOC_END
7028
d7f4a0b7
CT
7029NAME: note
7030TYPE: note
7031LOC: Config.notes
7032DEFAULT: none
7033DOC_START
7034 This option used to log custom information about the master
7035 transaction. For example, an admin may configure Squid to log
7036 which "user group" the transaction belongs to, where "user group"
7037 will be determined based on a set of ACLs and not [just]
7038 authentication information.
7039 Values of key/value pairs can be logged using %{key}note macros:
7040
7041 note key value acl ...
7042 logformat myFormat ... %{key}note ...
480926bd
EB
7043
7044 This clause only supports fast acl types.
7045 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
d7f4a0b7
CT
7046DOC_END
7047
41bd17a4 7048NAME: relaxed_header_parser
7049COMMENT: on|off|warn
7050TYPE: tristate
7051LOC: Config.onoff.relaxed_header_parser
7052DEFAULT: on
7053DOC_START
7054 In the default "on" setting Squid accepts certain forms
7055 of non-compliant HTTP messages where it is unambiguous
7056 what the sending application intended even if the message
7057 is not correctly formatted. The messages is then normalized
7058 to the correct form when forwarded by Squid.
cccac0a2 7059
41bd17a4 7060 If set to "warn" then a warning will be emitted in cache.log
7061 each time such HTTP error is encountered.
cccac0a2 7062
41bd17a4 7063 If set to "off" then such HTTP errors will cause the request
7064 or response to be rejected.
7065DOC_END
7d90757b 7066
55eae904
AR
7067NAME: collapsed_forwarding
7068COMMENT: (on|off)
7069TYPE: onoff
7070LOC: Config.onoff.collapsed_forwarding
7071DEFAULT: off
7072DOC_START
7073 This option controls whether Squid is allowed to merge multiple
7074 potentially cachable requests for the same URI before Squid knows
7075 whether the response is going to be cachable.
7076
1a210de4
EB
7077 When enabled, instead of forwarding each concurrent request for
7078 the same URL, Squid just sends the first of them. The other, so
7079 called "collapsed" requests, wait for the response to the first
7080 request and, if it happens to be cachable, use that response.
7081 Here, "concurrent requests" means "received after the first
7082 request headers were parsed and before the corresponding response
7083 headers were parsed".
7084
7085 This feature is disabled by default: enabling collapsed
7086 forwarding needlessly delays forwarding requests that look
7087 cachable (when they are collapsed) but then need to be forwarded
7088 individually anyway because they end up being for uncachable
7089 content. However, in some cases, such as acceleration of highly
7090 cachable content with periodic or grouped expiration times, the
7091 gains from collapsing [large volumes of simultaneous refresh
7092 requests] outweigh losses from such delays.
7093
7094 Squid collapses two kinds of requests: regular client requests
7095 received on one of the listening ports and internal "cache
7096 revalidation" requests which are triggered by those regular
7097 requests hitting a stale cached object. Revalidation collapsing
7098 is currently disabled for Squid instances containing SMP-aware
7099 disk or memory caches and for Vary-controlled cached objects.
55eae904
AR
7100DOC_END
7101
819be284
EB
7102NAME: collapsed_forwarding_access
7103TYPE: acl_access
7104DEFAULT: none
7105DEFAULT_DOC: Requests may be collapsed if collapsed_forwarding is on.
7106LOC: Config.accessList.collapsedForwardingAccess
7107DOC_START
7108 Use this directive to restrict collapsed forwarding to a subset of
7109 eligible requests. The directive is checked for regular HTTP
7110 requests, internal revalidation requests, and HTCP/ICP requests.
7111
7112 collapsed_forwarding_access allow|deny [!]aclname ...
7113
7114 This directive cannot force collapsing. It has no effect on
7115 collapsing unless collapsed_forwarding is 'on', and all other
7116 collapsing preconditions are satisfied.
7117
7118 * A denied request will not collapse, and future transactions will
7119 not collapse on it (even if they are allowed to collapse).
7120
7121 * An allowed request may collapse, or future transactions may
7122 collapse on it (provided they are allowed to collapse).
7123
7124 This directive is evaluated before receiving HTTP response headers
7125 and without access to Squid-to-peer connection (if any).
7126
7127 Only fast ACLs are supported.
7128
7129 See also: collapsed_forwarding.
7130DOC_END
7131
daed75a9 7132NAME: shared_transient_entries_limit collapsed_forwarding_shared_entries_limit
8f7dbf74
DD
7133COMMENT: (number of entries)
7134TYPE: int64_t
daed75a9 7135LOC: Config.shared_transient_entries_limit
8f7dbf74
DD
7136DEFAULT: 16384
7137DOC_START
daed75a9
EB
7138 This directive limits the size of a table used for sharing current
7139 transaction information among SMP workers. A table entry stores meta
7140 information about a single cache entry being delivered to Squid
7141 client(s) by one or more SMP workers. A single table entry consumes
7142 less than 128 shared memory bytes.
8f7dbf74 7143
daed75a9
EB
7144 The limit should be significantly larger than the number of
7145 concurrent non-collapsed cachable responses leaving Squid. For a
7146 cache that handles less than 5000 concurrent requests, the default
8f7dbf74
DD
7147 setting of 16384 should be plenty.
7148
daed75a9
EB
7149 Using excessively large values wastes shared memory. Limiting the
7150 table size too much results in hash collisions, leading to lower hit
7151 ratio and missed SMP request collapsing opportunities: Transactions
7152 left without a table entry cannot cache their responses and are
7153 invisible to other concurrent requests for the same resource.
7154
7155 A zero limit is allowed but unsupported. A positive small limit
7156 lowers hit ratio, but zero limit disables a lot of essential
7157 synchronization among SMP workers, leading to HTTP violations (e.g.,
7158 stale hit responses). It also disables shared collapsed forwarding:
7159 A worker becomes unable to collapse its requests on transactions in
7160 other workers, resulting in more trips to the origin server and more
7161 cache thrashing.
8f7dbf74
DD
7162DOC_END
7163
41bd17a4 7164COMMENT_START
7165 TIMEOUTS
7166 -----------------------------------------------------------------------------
7167COMMENT_END
7168
7169NAME: forward_timeout
7170COMMENT: time-units
7171TYPE: time_t
7172LOC: Config.Timeout.forward
7173DEFAULT: 4 minutes
7174DOC_START
7175 This parameter specifies how long Squid should at most attempt in
7176 finding a forwarding path for the request before giving up.
cccac0a2 7177DOC_END
7178
41bd17a4 7179NAME: connect_timeout
7180COMMENT: time-units
7181TYPE: time_t
7182LOC: Config.Timeout.connect
7183DEFAULT: 1 minute
057f5854 7184DOC_START
41bd17a4 7185 This parameter specifies how long to wait for the TCP connect to
7186 the requested server or peer to complete before Squid should
7187 attempt to find another path where to forward the request.
057f5854 7188DOC_END
7189
41bd17a4 7190NAME: peer_connect_timeout
7191COMMENT: time-units
7192TYPE: time_t
7193LOC: Config.Timeout.peer_connect
7194DEFAULT: 30 seconds
cccac0a2 7195DOC_START
41bd17a4 7196 This parameter specifies how long to wait for a pending TCP
7197 connection to a peer cache. The default is 30 seconds. You
7198 may also set different timeout values for individual neighbors
7199 with the 'connect-timeout' option on a 'cache_peer' line.
7200DOC_END
7f7db318 7201
41bd17a4 7202NAME: read_timeout
7203COMMENT: time-units
7204TYPE: time_t
7205LOC: Config.Timeout.read
7206DEFAULT: 15 minutes
7207DOC_START
d5430dc8
AJ
7208 Applied on peer server connections.
7209
7210 After each successful read(), the timeout will be extended by this
41bd17a4 7211 amount. If no data is read again after this amount of time,
d5430dc8
AJ
7212 the request is aborted and logged with ERR_READ_TIMEOUT.
7213
7214 The default is 15 minutes.
41bd17a4 7215DOC_END
cccac0a2 7216
5ef5e5cc
AJ
7217NAME: write_timeout
7218COMMENT: time-units
7219TYPE: time_t
7220LOC: Config.Timeout.write
7221DEFAULT: 15 minutes
7222DOC_START
7223 This timeout is tracked for all connections that have data
7224 available for writing and are waiting for the socket to become
7225 ready. After each successful write, the timeout is extended by
7226 the configured amount. If Squid has data to write but the
7227 connection is not ready for the configured duration, the
7228 transaction associated with the connection is terminated. The
7229 default is 15 minutes.
7230DOC_END
7231
41bd17a4 7232NAME: request_timeout
7233TYPE: time_t
7234LOC: Config.Timeout.request
7235DEFAULT: 5 minutes
7236DOC_START
6b2a2108 7237 How long to wait for complete HTTP request headers after initial
41bd17a4 7238 connection establishment.
7239DOC_END
cccac0a2 7240
3248e962
CT
7241NAME: request_start_timeout
7242TYPE: time_t
7243LOC: Config.Timeout.request_start_timeout
7244DEFAULT: 5 minutes
7245DOC_START
7246 How long to wait for the first request byte after initial
7247 connection establishment.
7248DOC_END
7249
97b32442 7250NAME: client_idle_pconn_timeout persistent_request_timeout
41bd17a4 7251TYPE: time_t
97b32442 7252LOC: Config.Timeout.clientIdlePconn
41bd17a4 7253DEFAULT: 2 minutes
7254DOC_START
7255 How long to wait for the next HTTP request on a persistent
97b32442 7256 client connection after the previous request completes.
41bd17a4 7257DOC_END
cccac0a2 7258
f6e8754a
AR
7259NAME: ftp_client_idle_timeout
7260TYPE: time_t
7261LOC: Config.Timeout.ftpClientIdle
7262DEFAULT: 30 minutes
7263DOC_START
7264 How long to wait for an FTP request on a connection to Squid ftp_port.
7265 Many FTP clients do not deal with idle connection closures well,
7266 necessitating a longer default timeout than client_idle_pconn_timeout
7267 used for incoming HTTP requests.
7268DOC_END
7269
41bd17a4 7270NAME: client_lifetime
7271COMMENT: time-units
7272TYPE: time_t
7273LOC: Config.Timeout.lifetime
7274DEFAULT: 1 day
7275DOC_START
7276 The maximum amount of time a client (browser) is allowed to
7277 remain connected to the cache process. This protects the Cache
7278 from having a lot of sockets (and hence file descriptors) tied up
7279 in a CLOSE_WAIT state from remote clients that go away without
7280 properly shutting down (either because of a network failure or
7281 because of a poor client implementation). The default is one
7282 day, 1440 minutes.
7d90757b 7283
41bd17a4 7284 NOTE: The default value is intended to be much larger than any
7285 client would ever need to be connected to your cache. You
7286 should probably change client_lifetime only as a last resort.
7287 If you seem to have many client connections tying up
7288 filedescriptors, we recommend first tuning the read_timeout,
7289 request_timeout, persistent_request_timeout and quick_abort values.
cccac0a2 7290DOC_END
7291
c5c06f02
CT
7292NAME: pconn_lifetime
7293COMMENT: time-units
7294TYPE: time_t
7295LOC: Config.Timeout.pconnLifetime
7296DEFAULT: 0 seconds
7297DOC_START
7298 Desired maximum lifetime of a persistent connection.
7299 When set, Squid will close a now-idle persistent connection that
7300 exceeded configured lifetime instead of moving the connection into
7301 the idle connection pool (or equivalent). No effect on ongoing/active
7302 transactions. Connection lifetime is the time period from the
7303 connection acceptance or opening time until "now".
9603207d 7304
c5c06f02
CT
7305 This limit is useful in environments with long-lived connections
7306 where Squid configuration or environmental factors change during a
7307 single connection lifetime. If unrestricted, some connections may
7308 last for hours and even days, ignoring those changes that should
7309 have affected their behavior or their existence.
9603207d 7310
c5c06f02
CT
7311 Currently, a new lifetime value supplied via Squid reconfiguration
7312 has no effect on already idle connections unless they become busy.
9603207d 7313
c5c06f02
CT
7314 When set to '0' this limit is not used.
7315DOC_END
7316
41bd17a4 7317NAME: half_closed_clients
7318TYPE: onoff
7319LOC: Config.onoff.half_closed_clients
0c2f5c4f 7320DEFAULT: off
4eb368f9 7321DOC_START
41bd17a4 7322 Some clients may shutdown the sending side of their TCP
7323 connections, while leaving their receiving sides open. Sometimes,
7324 Squid can not tell the difference between a half-closed and a
0c2f5c4f
AJ
7325 fully-closed TCP connection.
7326
7327 By default, Squid will immediately close client connections when
7328 read(2) returns "no more data to read."
7329
abdf1651 7330 Change this option to 'on' and Squid will keep open connections
0c2f5c4f
AJ
7331 until a read(2) or write(2) on the socket returns an error.
7332 This may show some benefits for reverse proxies. But if not
7333 it is recommended to leave OFF.
4eb368f9 7334DOC_END
7335
97b32442 7336NAME: server_idle_pconn_timeout pconn_timeout
41bd17a4 7337TYPE: time_t
97b32442 7338LOC: Config.Timeout.serverIdlePconn
41bd17a4 7339DEFAULT: 1 minute
cccac0a2 7340DOC_START
41bd17a4 7341 Timeout for idle persistent connections to servers and other
7342 proxies.
7343DOC_END
cccac0a2 7344
41bd17a4 7345NAME: ident_timeout
7346TYPE: time_t
7347IFDEF: USE_IDENT
4daaf3cb 7348LOC: Ident::TheConfig.timeout
41bd17a4 7349DEFAULT: 10 seconds
7350DOC_START
7351 Maximum time to wait for IDENT lookups to complete.
cccac0a2 7352
41bd17a4 7353 If this is too high, and you enabled IDENT lookups from untrusted
7354 users, you might be susceptible to denial-of-service by having
7355 many ident requests going at once.
cccac0a2 7356DOC_END
7357
41bd17a4 7358NAME: shutdown_lifetime
7359COMMENT: time-units
7360TYPE: time_t
7361LOC: Config.shutdownLifetime
7362DEFAULT: 30 seconds
cccac0a2 7363DOC_START
41bd17a4 7364 When SIGTERM or SIGHUP is received, the cache is put into
7365 "shutdown pending" mode until all active sockets are closed.
7366 This value is the lifetime to set for all open descriptors
7367 during shutdown mode. Any active clients after this many
7368 seconds will receive a 'timeout' message.
cccac0a2 7369DOC_END
0976f8db 7370
cccac0a2 7371COMMENT_START
7372 ADMINISTRATIVE PARAMETERS
7373 -----------------------------------------------------------------------------
7374COMMENT_END
7375
7376NAME: cache_mgr
7377TYPE: string
7378DEFAULT: webmaster
7379LOC: Config.adminEmail
7380DOC_START
7381 Email-address of local cache manager who will receive
638402dd 7382 mail if the cache dies. The default is "webmaster".
cccac0a2 7383DOC_END
7384
abacf776 7385NAME: mail_from
7386TYPE: string
7387DEFAULT: none
7388LOC: Config.EmailFrom
7389DOC_START
7390 From: email-address for mail sent when the cache dies.
638402dd
AJ
7391 The default is to use 'squid@unique_hostname'.
7392
7393 See also: unique_hostname directive.
abacf776 7394DOC_END
7395
d084bf20 7396NAME: mail_program
7397TYPE: eol
7398DEFAULT: mail
7399LOC: Config.EmailProgram
7400DOC_START
7401 Email program used to send mail if the cache dies.
846a5e31 7402 The default is "mail". The specified program must comply
d084bf20 7403 with the standard Unix mail syntax:
846a5e31 7404 mail-program recipient < mailfile
7405
d084bf20 7406 Optional command line options can be specified.
7407DOC_END
7408
cccac0a2 7409NAME: cache_effective_user
7410TYPE: string
5483d916 7411DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
cccac0a2 7412LOC: Config.effectiveUser
e3d74828 7413DOC_START
7414 If you start Squid as root, it will change its effective/real
7415 UID/GID to the user specified below. The default is to change
5483d916 7416 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
64e288bd 7417 see also; cache_effective_group
e3d74828 7418DOC_END
7419
cccac0a2 7420NAME: cache_effective_group
7421TYPE: string
7422DEFAULT: none
638402dd 7423DEFAULT_DOC: Use system group memberships of the cache_effective_user account
cccac0a2 7424LOC: Config.effectiveGroup
7425DOC_START
64e288bd 7426 Squid sets the GID to the effective user's default group ID
7427 (taken from the password file) and supplementary group list
7428 from the groups membership.
7429
e3d74828 7430 If you want Squid to run with a specific GID regardless of
7431 the group memberships of the effective user then set this
7432 to the group (or GID) you want Squid to run as. When set
64e288bd 7433 all other group privileges of the effective user are ignored
e3d74828 7434 and only this GID is effective. If Squid is not started as
64e288bd 7435 root the user starting Squid MUST be member of the specified
e3d74828 7436 group.
64e288bd 7437
7438 This option is not recommended by the Squid Team.
7439 Our preference is for administrators to configure a secure
7440 user account for squid with UID/GID matching system policies.
cccac0a2 7441DOC_END
7442
d3caee79 7443NAME: httpd_suppress_version_string
7444COMMENT: on|off
7445TYPE: onoff
7446DEFAULT: off
7447LOC: Config.onoff.httpd_suppress_version_string
7448DOC_START
7449 Suppress Squid version string info in HTTP headers and HTML error pages.
7450DOC_END
7451
cccac0a2 7452NAME: visible_hostname
7453TYPE: string
7454LOC: Config.visibleHostname
7455DEFAULT: none
638402dd 7456DEFAULT_DOC: Automatically detect the system host name
cccac0a2 7457DOC_START
7458 If you want to present a special hostname in error messages, etc,
7f7db318 7459 define this. Otherwise, the return value of gethostname()
cccac0a2 7460 will be used. If you have multiple caches in a cluster and
7461 get errors about IP-forwarding you must set them to have individual
7462 names with this setting.
7463DOC_END
7464
cccac0a2 7465NAME: unique_hostname
7466TYPE: string
7467LOC: Config.uniqueHostname
7468DEFAULT: none
638402dd 7469DEFAULT_DOC: Copy the value from visible_hostname
cccac0a2 7470DOC_START
7471 If you want to have multiple machines with the same
7f7db318 7472 'visible_hostname' you must give each machine a different
7473 'unique_hostname' so forwarding loops can be detected.
cccac0a2 7474DOC_END
7475
cccac0a2 7476NAME: hostname_aliases
7477TYPE: wordlist
7478LOC: Config.hostnameAliases
7479DEFAULT: none
7480DOC_START
7f7db318 7481 A list of other DNS names your cache has.
cccac0a2 7482DOC_END
0976f8db 7483
c642c141
AJ
7484NAME: umask
7485TYPE: int
7486LOC: Config.umask
7487DEFAULT: 027
7488DOC_START
7489 Minimum umask which should be enforced while the proxy
7490 is running, in addition to the umask set at startup.
7491
7492 For a traditional octal representation of umasks, start
7493 your value with 0.
7494DOC_END
7495
cccac0a2 7496COMMENT_START
7497 OPTIONS FOR THE CACHE REGISTRATION SERVICE
7498 -----------------------------------------------------------------------------
7499
7500 This section contains parameters for the (optional) cache
7501 announcement service. This service is provided to help
7502 cache administrators locate one another in order to join or
7503 create cache hierarchies.
7504
7505 An 'announcement' message is sent (via UDP) to the registration
7506 service by Squid. By default, the announcement message is NOT
7507 SENT unless you enable it with 'announce_period' below.
7508
7509 The announcement message includes your hostname, plus the
7510 following information from this configuration file:
7511
7512 http_port
7513 icp_port
7514 cache_mgr
7515
7516 All current information is processed regularly and made
7517 available on the Web at http://www.ircache.net/Cache/Tracker/.
7518COMMENT_END
7519
7520NAME: announce_period
7521TYPE: time_t
7522LOC: Config.Announce.period
7523DEFAULT: 0
638402dd 7524DEFAULT_DOC: Announcement messages disabled.
cccac0a2 7525DOC_START
638402dd 7526 This is how frequently to send cache announcements.
cccac0a2 7527
e0855596 7528 To enable announcing your cache, just set an announce period.
cccac0a2 7529
e0855596
AJ
7530 Example:
7531 announce_period 1 day
cccac0a2 7532DOC_END
7533
cccac0a2 7534NAME: announce_host
7535TYPE: string
7536DEFAULT: tracker.ircache.net
7537LOC: Config.Announce.host
638402dd
AJ
7538DOC_START
7539 Set the hostname where announce registration messages will be sent.
7540
7541 See also announce_port and announce_file
7542DOC_END
cccac0a2 7543
7544NAME: announce_file
7545TYPE: string
7546DEFAULT: none
7547LOC: Config.Announce.file
638402dd
AJ
7548DOC_START
7549 The contents of this file will be included in the announce
7550 registration messages.
7551DOC_END
cccac0a2 7552
7553NAME: announce_port
ae870270 7554TYPE: u_short
cccac0a2 7555DEFAULT: 3131
7556LOC: Config.Announce.port
7557DOC_START
638402dd 7558 Set the port where announce registration messages will be sent.
cccac0a2 7559
638402dd 7560 See also announce_host and announce_file
cccac0a2 7561DOC_END
7562
8d6275c0 7563COMMENT_START
7564 HTTPD-ACCELERATOR OPTIONS
7565 -----------------------------------------------------------------------------
7566COMMENT_END
7567
cccac0a2 7568NAME: httpd_accel_surrogate_id
cccac0a2 7569TYPE: string
b2b40d8c 7570DEFAULT: none
638402dd 7571DEFAULT_DOC: visible_hostname is used if no specific ID is set.
cccac0a2 7572LOC: Config.Accel.surrogate_id
cccac0a2 7573DOC_START
7574 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
7575 need an identification token to allow control targeting. Because
7576 a farm of surrogates may all perform the same tasks, they may share
7577 an identification token.
609d5e06
AJ
7578
7579 When the surrogate is a reverse-proxy, this ID is also
7580 used as cdn-id for CDN-Loop detection (RFC 8586).
cccac0a2 7581DOC_END
7582
7583NAME: http_accel_surrogate_remote
cccac0a2 7584COMMENT: on|off
7585TYPE: onoff
7586DEFAULT: off
7587LOC: Config.onoff.surrogate_is_remote
7588DOC_START
638402dd
AJ
7589 Remote surrogates (such as those in a CDN) honour the header
7590 "Surrogate-Control: no-store-remote".
7591
cccac0a2 7592 Set this to on to have squid behave as a remote surrogate.
7593DOC_END
7594
7595NAME: esi_parser
f41735ea 7596IFDEF: USE_SQUID_ESI
799b66d1 7597COMMENT: libxml2|expat
cccac0a2 7598TYPE: string
7599LOC: ESIParser::Type
799b66d1
AJ
7600DEFAULT: auto
7601DEFAULT_DOC: Selects libxml2 if available at ./configure time or libexpat otherwise.
cccac0a2 7602DOC_START
799b66d1
AJ
7603 Selects the XML parsing library to use when interpreting responses with
7604 Edge Side Includes.
7605
7606 To disable ESI handling completely, ./configure Squid with --disable-esi.
cccac0a2 7607DOC_END
0976f8db 7608
9edd9041 7609COMMENT_START
8d6275c0 7610 DELAY POOL PARAMETERS
9edd9041 7611 -----------------------------------------------------------------------------
7612COMMENT_END
7613
7614NAME: delay_pools
7615TYPE: delay_pool_count
7616DEFAULT: 0
9a0a18de 7617IFDEF: USE_DELAY_POOLS
9edd9041 7618LOC: Config.Delay
7619DOC_START
7620 This represents the number of delay pools to be used. For example,
7621 if you have one class 2 delay pool and one class 3 delays pool, you
7622 have a total of 2 delay pools.
638402dd
AJ
7623
7624 See also delay_parameters, delay_class, delay_access for pool
7625 configuration details.
9edd9041 7626DOC_END
7627
7628NAME: delay_class
7629TYPE: delay_pool_class
7630DEFAULT: none
9a0a18de 7631IFDEF: USE_DELAY_POOLS
9edd9041 7632LOC: Config.Delay
7633DOC_START
7634 This defines the class of each delay pool. There must be exactly one
7635 delay_class line for each delay pool. For example, to define two
7636 delay pools, one of class 2 and one of class 3, the settings above
7637 and here would be:
7638
b1fb3348
AJ
7639 Example:
7640 delay_pools 4 # 4 delay pools
7641 delay_class 1 2 # pool 1 is a class 2 pool
7642 delay_class 2 3 # pool 2 is a class 3 pool
7643 delay_class 3 4 # pool 3 is a class 4 pool
7644 delay_class 4 5 # pool 4 is a class 5 pool
9edd9041 7645
7646 The delay pool classes are:
7647
7648 class 1 Everything is limited by a single aggregate
7649 bucket.
7650
7651 class 2 Everything is limited by a single aggregate
7652 bucket as well as an "individual" bucket chosen
b1fb3348 7653 from bits 25 through 32 of the IPv4 address.
9edd9041 7654
7655 class 3 Everything is limited by a single aggregate
7656 bucket as well as a "network" bucket chosen
7657 from bits 17 through 24 of the IP address and a
7658 "individual" bucket chosen from bits 17 through
b1fb3348 7659 32 of the IPv4 address.
9edd9041 7660
7661 class 4 Everything in a class 3 delay pool, with an
7662 additional limit on a per user basis. This
7663 only takes effect if the username is established
7664 in advance - by forcing authentication in your
7665 http_access rules.
7666
7667 class 5 Requests are grouped according their tag (see
7668 external_acl's tag= reply).
7669
0b68481a
AJ
7670
7671 Each pool also requires a delay_parameters directive to configure the pool size
7672 and speed limits used whenever the pool is applied to a request. Along with
7673 a set of delay_access directives to determine when it is used.
7674
9edd9041 7675 NOTE: If an IP address is a.b.c.d
7676 -> bits 25 through 32 are "d"
7677 -> bits 17 through 24 are "c"
7678 -> bits 17 through 32 are "c * 256 + d"
b1fb3348
AJ
7679
7680 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
7681 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
638402dd
AJ
7682
7683 This clause only supports fast acl types.
7684 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7685
7686 See also delay_parameters and delay_access.
9edd9041 7687DOC_END
7688
7689NAME: delay_access
7690TYPE: delay_pool_access
7691DEFAULT: none
638402dd 7692DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
9a0a18de 7693IFDEF: USE_DELAY_POOLS
9edd9041 7694LOC: Config.Delay
7695DOC_START
7696 This is used to determine which delay pool a request falls into.
7697
7698 delay_access is sorted per pool and the matching starts with pool 1,
7699 then pool 2, ..., and finally pool N. The first delay pool where the
7700 request is allowed is selected for the request. If it does not allow
7701 the request to any pool then the request is not delayed (default).
7702
7703 For example, if you want some_big_clients in delay
7704 pool 1 and lotsa_little_clients in delay pool 2:
7705
638402dd
AJ
7706 delay_access 1 allow some_big_clients
7707 delay_access 1 deny all
7708 delay_access 2 allow lotsa_little_clients
7709 delay_access 2 deny all
7710 delay_access 3 allow authenticated_clients
7711
7712 See also delay_parameters and delay_class.
7713
9edd9041 7714DOC_END
7715
7716NAME: delay_parameters
7717TYPE: delay_pool_rates
7718DEFAULT: none
9a0a18de 7719IFDEF: USE_DELAY_POOLS
9edd9041 7720LOC: Config.Delay
7721DOC_START
7722 This defines the parameters for a delay pool. Each delay pool has
7723 a number of "buckets" associated with it, as explained in the
0b68481a 7724 description of delay_class.
9edd9041 7725
0b68481a 7726 For a class 1 delay pool, the syntax is:
6e7502cc 7727 delay_class pool 1
0b68481a 7728 delay_parameters pool aggregate
9edd9041 7729
7730 For a class 2 delay pool:
6e7502cc 7731 delay_class pool 2
0b68481a 7732 delay_parameters pool aggregate individual
9edd9041 7733
7734 For a class 3 delay pool:
6e7502cc 7735 delay_class pool 3
0b68481a 7736 delay_parameters pool aggregate network individual
9edd9041 7737
7738 For a class 4 delay pool:
6e7502cc 7739 delay_class pool 4
0b68481a 7740 delay_parameters pool aggregate network individual user
9edd9041 7741
7742 For a class 5 delay pool:
6e7502cc 7743 delay_class pool 5
0b68481a 7744 delay_parameters pool tagrate
9edd9041 7745
0b68481a 7746 The option variables are:
9edd9041 7747
7748 pool a pool number - ie, a number between 1 and the
7749 number specified in delay_pools as used in
7750 delay_class lines.
7751
fdb47ac6 7752 aggregate the speed limit parameters for the aggregate bucket
9edd9041 7753 (class 1, 2, 3).
7754
fdb47ac6 7755 individual the speed limit parameters for the individual
9edd9041 7756 buckets (class 2, 3).
7757
fdb47ac6 7758 network the speed limit parameters for the network buckets
9edd9041 7759 (class 3).
7760
fdb47ac6 7761 user the speed limit parameters for the user buckets
9edd9041 7762 (class 4).
7763
fdb47ac6 7764 tagrate the speed limit parameters for the tag buckets
9edd9041 7765 (class 5).
7766
7767 A pair of delay parameters is written restore/maximum, where restore is
7768 the number of bytes (not bits - modem and network speeds are usually
7769 quoted in bits) per second placed into the bucket, and maximum is the
7770 maximum number of bytes which can be in the bucket at any time.
7771
0b68481a
AJ
7772 There must be one delay_parameters line for each delay pool.
7773
7774
9edd9041 7775 For example, if delay pool number 1 is a class 2 delay pool as in the
0b68481a 7776 above example, and is being used to strictly limit each host to 64Kbit/sec
9edd9041 7777 (plus overheads), with no overall limit, the line is:
7778
6e7502cc 7779 delay_parameters 1 none 8000/8000
0b68481a 7780
c3e31a3a 7781 Note that 8 x 8K Byte/sec -> 64K bit/sec.
9edd9041 7782
6e7502cc 7783 Note that the word 'none' is used to represent no limit.
9edd9041 7784
0b68481a 7785
9edd9041 7786 And, if delay pool number 2 is a class 3 delay pool as in the above
0b68481a
AJ
7787 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
7788 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
7789 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
9edd9041 7790 to permit a decent web page to be downloaded at a decent speed
7791 (if the network is not being limited due to overuse) but slow down
7792 large downloads more significantly:
7793
0b68481a
AJ
7794 delay_parameters 2 32000/32000 8000/8000 600/8000
7795
c3e31a3a
AJ
7796 Note that 8 x 32K Byte/sec -> 256K bit/sec.
7797 8 x 8K Byte/sec -> 64K bit/sec.
7798 8 x 600 Byte/sec -> 4800 bit/sec.
9edd9041 7799
9edd9041 7800
7801 Finally, for a class 4 delay pool as in the example - each user will
0b68481a 7802 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
9edd9041 7803
0b68481a 7804 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
638402dd
AJ
7805
7806
7807 See also delay_class and delay_access.
7808
9edd9041 7809DOC_END
7810
7811NAME: delay_initial_bucket_level
7812COMMENT: (percent, 0-100)
ae870270 7813TYPE: u_short
9edd9041 7814DEFAULT: 50
9a0a18de 7815IFDEF: USE_DELAY_POOLS
9edd9041 7816LOC: Config.Delay.initial
7817DOC_START
7818 The initial bucket percentage is used to determine how much is put
7819 in each bucket when squid starts, is reconfigured, or first notices
7820 a host accessing it (in class 2 and class 3, individual hosts and
7821 networks only have buckets associated with them once they have been
7822 "seen" by squid).
7823DOC_END
7824
b4cd430a
CT
7825COMMENT_START
7826 CLIENT DELAY POOL PARAMETERS
7827 -----------------------------------------------------------------------------
7828COMMENT_END
7829
7830NAME: client_delay_pools
7831TYPE: client_delay_pool_count
7832DEFAULT: 0
9a0a18de 7833IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7834LOC: Config.ClientDelay
7835DOC_START
7836 This option specifies the number of client delay pools used. It must
7837 preceed other client_delay_* options.
7838
638402dd
AJ
7839 Example:
7840 client_delay_pools 2
7841
7842 See also client_delay_parameters and client_delay_access.
b4cd430a
CT
7843DOC_END
7844
7845NAME: client_delay_initial_bucket_level
7846COMMENT: (percent, 0-no_limit)
ae870270 7847TYPE: u_short
b4cd430a 7848DEFAULT: 50
9a0a18de 7849IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7850LOC: Config.ClientDelay.initial
7851DOC_START
7852 This option determines the initial bucket size as a percentage of
7853 max_bucket_size from client_delay_parameters. Buckets are created
7854 at the time of the "first" connection from the matching IP. Idle
7855 buckets are periodically deleted up.
7856
7857 You can specify more than 100 percent but note that such "oversized"
7858 buckets are not refilled until their size goes down to max_bucket_size
7859 from client_delay_parameters.
7860
638402dd
AJ
7861 Example:
7862 client_delay_initial_bucket_level 50
b4cd430a
CT
7863DOC_END
7864
7865NAME: client_delay_parameters
7866TYPE: client_delay_pool_rates
7867DEFAULT: none
9a0a18de 7868IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7869LOC: Config.ClientDelay
7870DOC_START
7871
7872 This option configures client-side bandwidth limits using the
7873 following format:
7874
7875 client_delay_parameters pool speed_limit max_bucket_size
7876
7877 pool is an integer ID used for client_delay_access matching.
7878
7879 speed_limit is bytes added to the bucket per second.
7880
7881 max_bucket_size is the maximum size of a bucket, enforced after any
7882 speed_limit additions.
7883
7884 Please see the delay_parameters option for more information and
7885 examples.
7886
638402dd
AJ
7887 Example:
7888 client_delay_parameters 1 1024 2048
7889 client_delay_parameters 2 51200 16384
7890
7891 See also client_delay_access.
7892
b4cd430a
CT
7893DOC_END
7894
7895NAME: client_delay_access
7896TYPE: client_delay_pool_access
7897DEFAULT: none
638402dd 7898DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
9a0a18de 7899IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7900LOC: Config.ClientDelay
7901DOC_START
b4cd430a
CT
7902 This option determines the client-side delay pool for the
7903 request:
7904
7905 client_delay_access pool_ID allow|deny acl_name
7906
7907 All client_delay_access options are checked in their pool ID
7908 order, starting with pool 1. The first checked pool with allowed
7909 request is selected for the request. If no ACL matches or there
7910 are no client_delay_access options, the request bandwidth is not
7911 limited.
7912
7913 The ACL-selected pool is then used to find the
7914 client_delay_parameters for the request. Client-side pools are
7915 not used to aggregate clients. Clients are always aggregated
7916 based on their source IP addresses (one bucket per source IP).
7917
638402dd
AJ
7918 This clause only supports fast acl types.
7919 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7920 Additionally, only the client TCP connection details are available.
7921 ACLs testing HTTP properties will not work.
7922
b4cd430a
CT
7923 Please see delay_access for more examples.
7924
638402dd
AJ
7925 Example:
7926 client_delay_access 1 allow low_rate_network
7927 client_delay_access 2 allow vips_network
7928
7929
7930 See also client_delay_parameters and client_delay_pools.
b4cd430a
CT
7931DOC_END
7932
b27668ec
EB
7933NAME: response_delay_pool
7934TYPE: response_delay_pool_parameters
7935DEFAULT: none
7936IFDEF: USE_DELAY_POOLS
7937LOC: Config.MessageDelay
7938DOC_START
7939 This option configures client response bandwidth limits using the
7940 following format:
7941
7942 response_delay_pool name [option=value] ...
7943
7944 name the response delay pool name
7945
7946 available options:
7947
7948 individual-restore The speed limit of an individual
7949 bucket(bytes/s). To be used in conjunction
7950 with 'individual-maximum'.
7951
7952 individual-maximum The maximum number of bytes which can
7953 be placed into the individual bucket. To be used
7954 in conjunction with 'individual-restore'.
7955
7956 aggregate-restore The speed limit for the aggregate
7957 bucket(bytes/s). To be used in conjunction with
7958 'aggregate-maximum'.
7959
7960 aggregate-maximum The maximum number of bytes which can
7961 be placed into the aggregate bucket. To be used
7962 in conjunction with 'aggregate-restore'.
7963
7964 initial-bucket-level The initial bucket size as a percentage
7965 of individual-maximum.
7966
7967 Individual and(or) aggregate bucket options may not be specified,
7968 meaning no individual and(or) aggregate speed limitation.
7969 See also response_delay_pool_access and delay_parameters for
7970 terminology details.
7971DOC_END
7972
7973NAME: response_delay_pool_access
7974TYPE: response_delay_pool_access
7975DEFAULT: none
7976DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
7977IFDEF: USE_DELAY_POOLS
7978LOC: Config.MessageDelay
7979DOC_START
7980 Determines whether a specific named response delay pool is used
7981 for the transaction. The syntax for this directive is:
7982
7983 response_delay_pool_access pool_name allow|deny acl_name
7984
7985 All response_delay_pool_access options are checked in the order
7986 they appear in this configuration file. The first rule with a
7987 matching ACL wins. If (and only if) an "allow" rule won, Squid
7988 assigns the response to the corresponding named delay pool.
7989DOC_END
7990
cccac0a2 7991COMMENT_START
8d6275c0 7992 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
cccac0a2 7993 -----------------------------------------------------------------------------
7994COMMENT_END
7995
8d6275c0 7996NAME: wccp_router
7997TYPE: address
7998LOC: Config.Wccp.router
0eb08770 7999DEFAULT: any_addr
638402dd 8000DEFAULT_DOC: WCCP disabled.
8d6275c0 8001IFDEF: USE_WCCP
e313ab0a
AJ
8002DOC_START
8003 Use this option to define your WCCP ``home'' router for
8004 Squid.
8005
8006 wccp_router supports a single WCCP(v1) router
8007
8008 wccp2_router supports multiple WCCPv2 routers
8009
8010 only one of the two may be used at the same time and defines
8011 which version of WCCP to use.
8012DOC_END
df2eec10 8013
8d6275c0 8014NAME: wccp2_router
9fb4efad 8015TYPE: IpAddress_list
8d6275c0 8016LOC: Config.Wccp2.router
cccac0a2 8017DEFAULT: none
638402dd 8018DEFAULT_DOC: WCCPv2 disabled.
8d6275c0 8019IFDEF: USE_WCCPv2
cccac0a2 8020DOC_START
8d6275c0 8021 Use this option to define your WCCP ``home'' router for
8022 Squid.
cccac0a2 8023
8d6275c0 8024 wccp_router supports a single WCCP(v1) router
cccac0a2 8025
8d6275c0 8026 wccp2_router supports multiple WCCPv2 routers
cccac0a2 8027
8d6275c0 8028 only one of the two may be used at the same time and defines
8029 which version of WCCP to use.
8030DOC_END
8031
8032NAME: wccp_version
cccac0a2 8033TYPE: int
8d6275c0 8034LOC: Config.Wccp.version
8035DEFAULT: 4
8036IFDEF: USE_WCCP
cccac0a2 8037DOC_START
8d6275c0 8038 This directive is only relevant if you need to set up WCCP(v1)
8039 to some very old and end-of-life Cisco routers. In all other
8040 setups it must be left unset or at the default setting.
8041 It defines an internal version in the WCCP(v1) protocol,
8042 with version 4 being the officially documented protocol.
cccac0a2 8043
8d6275c0 8044 According to some users, Cisco IOS 11.2 and earlier only
8045 support WCCP version 3. If you're using that or an earlier
8046 version of IOS, you may need to change this value to 3, otherwise
8047 do not specify this parameter.
cccac0a2 8048DOC_END
8049
8d6275c0 8050NAME: wccp2_rebuild_wait
8051TYPE: onoff
8052LOC: Config.Wccp2.rebuildwait
8053DEFAULT: on
8054IFDEF: USE_WCCPv2
8055DOC_START
8056 If this is enabled Squid will wait for the cache dir rebuild to finish
8057 before sending the first wccp2 HereIAm packet
8058DOC_END
cccac0a2 8059
8d6275c0 8060NAME: wccp2_forwarding_method
e313ab0a 8061TYPE: wccp2_method
8d6275c0 8062LOC: Config.Wccp2.forwarding_method
451c4786 8063DEFAULT: gre
8d6275c0 8064IFDEF: USE_WCCPv2
cccac0a2 8065DOC_START
699acd19 8066 WCCP2 allows the setting of forwarding methods between the
8d6275c0 8067 router/switch and the cache. Valid values are as follows:
cccac0a2 8068
451c4786
AJ
8069 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
8070 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
cccac0a2 8071
8d6275c0 8072 Currently (as of IOS 12.4) cisco routers only support GRE.
8073 Cisco switches only support the L2 redirect assignment method.
cccac0a2 8074DOC_END
8075
8d6275c0 8076NAME: wccp2_return_method
e313ab0a 8077TYPE: wccp2_method
8d6275c0 8078LOC: Config.Wccp2.return_method
451c4786 8079DEFAULT: gre
8d6275c0 8080IFDEF: USE_WCCPv2
cccac0a2 8081DOC_START
699acd19 8082 WCCP2 allows the setting of return methods between the
8d6275c0 8083 router/switch and the cache for packets that the cache
8084 decides not to handle. Valid values are as follows:
cccac0a2 8085
451c4786
AJ
8086 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
8087 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
cccac0a2 8088
8d6275c0 8089 Currently (as of IOS 12.4) cisco routers only support GRE.
8090 Cisco switches only support the L2 redirect assignment.
cccac0a2 8091
699acd19 8092 If the "ip wccp redirect exclude in" command has been
8d6275c0 8093 enabled on the cache interface, then it is still safe for
8094 the proxy server to use a l2 redirect method even if this
8095 option is set to GRE.
cccac0a2 8096DOC_END
8097
8d6275c0 8098NAME: wccp2_assignment_method
451c4786 8099TYPE: wccp2_amethod
8d6275c0 8100LOC: Config.Wccp2.assignment_method
451c4786 8101DEFAULT: hash
8d6275c0 8102IFDEF: USE_WCCPv2
cccac0a2 8103DOC_START
8d6275c0 8104 WCCP2 allows the setting of methods to assign the WCCP hash
8105 Valid values are as follows:
cccac0a2 8106
451c4786 8107 hash - Hash assignment
bb7a1781 8108 mask - Mask assignment
cccac0a2 8109
8d6275c0 8110 As a general rule, cisco routers support the hash assignment method
8111 and cisco switches support the mask assignment method.
8112DOC_END
cccac0a2 8113
8d6275c0 8114NAME: wccp2_service
8115TYPE: wccp2_service
8116LOC: Config.Wccp2.info
8d6275c0 8117DEFAULT_IF_NONE: standard 0
638402dd 8118DEFAULT_DOC: Use the 'web-cache' standard service.
8d6275c0 8119IFDEF: USE_WCCPv2
8120DOC_START
8121 WCCP2 allows for multiple traffic services. There are two
8122 types: "standard" and "dynamic". The standard type defines
8123 one service id - http (id 0). The dynamic service ids can be from
8124 51 to 255 inclusive. In order to use a dynamic service id
8125 one must define the type of traffic to be redirected; this is done
8126 using the wccp2_service_info option.
8127
8128 The "standard" type does not require a wccp2_service_info option,
8129 just specifying the service id will suffice.
8130
8131 MD5 service authentication can be enabled by adding
8132 "password=<password>" to the end of this service declaration.
8133
8134 Examples:
8135
8136 wccp2_service standard 0 # for the 'web-cache' standard service
8137 wccp2_service dynamic 80 # a dynamic service type which will be
8138 # fleshed out with subsequent options.
8139 wccp2_service standard 0 password=foo
8d6275c0 8140DOC_END
8141
8142NAME: wccp2_service_info
8143TYPE: wccp2_service_info
8144LOC: Config.Wccp2.info
8145DEFAULT: none
8146IFDEF: USE_WCCPv2
8147DOC_START
8148 Dynamic WCCPv2 services require further information to define the
8149 traffic you wish to have diverted.
8150
8151 The format is:
8152
8153 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
8154 priority=<priority> ports=<port>,<port>..
8155
8156 The relevant WCCPv2 flags:
8157 + src_ip_hash, dst_ip_hash
005fe566 8158 + source_port_hash, dst_port_hash
8d6275c0 8159 + src_ip_alt_hash, dst_ip_alt_hash
8160 + src_port_alt_hash, dst_port_alt_hash
8161 + ports_source
8162
8163 The port list can be one to eight entries.
8164
8165 Example:
8166
8167 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
8168 priority=240 ports=80
8169
8170 Note: the service id must have been defined by a previous
8171 'wccp2_service dynamic <id>' entry.
8172DOC_END
8173
8174NAME: wccp2_weight
8175TYPE: int
8176LOC: Config.Wccp2.weight
8177DEFAULT: 10000
8178IFDEF: USE_WCCPv2
8179DOC_START
8180 Each cache server gets assigned a set of the destination
8181 hash proportional to their weight.
8182DOC_END
8183
8184NAME: wccp_address
8185TYPE: address
8186LOC: Config.Wccp.address
8187DEFAULT: 0.0.0.0
638402dd 8188DEFAULT_DOC: Address selected by the operating system.
8d6275c0 8189IFDEF: USE_WCCP
638402dd 8190DOC_START
dfd5ce0a 8191 Use this option if you require WCCP(v1) to use a specific
638402dd
AJ
8192 interface address.
8193
8194 The default behavior is to not bind to any specific address.
8195DOC_END
df2eec10 8196
8d6275c0 8197NAME: wccp2_address
8198TYPE: address
8199LOC: Config.Wccp2.address
8200DEFAULT: 0.0.0.0
638402dd 8201DEFAULT_DOC: Address selected by the operating system.
8d6275c0 8202IFDEF: USE_WCCPv2
8203DOC_START
dfd5ce0a 8204 Use this option if you require WCCPv2 to use a specific
8d6275c0 8205 interface address.
8206
8207 The default behavior is to not bind to any specific address.
8208DOC_END
8209
8210COMMENT_START
8211 PERSISTENT CONNECTION HANDLING
8212 -----------------------------------------------------------------------------
8213
8214 Also see "pconn_timeout" in the TIMEOUTS section
8215COMMENT_END
8216
8217NAME: client_persistent_connections
8218TYPE: onoff
8219LOC: Config.onoff.client_pconns
8220DEFAULT: on
638402dd
AJ
8221DOC_START
8222 Persistent connection support for clients.
8223 Squid uses persistent connections (when allowed). You can use
8224 this option to disable persistent connections with clients.
8225DOC_END
8d6275c0 8226
8227NAME: server_persistent_connections
8228TYPE: onoff
8229LOC: Config.onoff.server_pconns
8230DEFAULT: on
8231DOC_START
638402dd
AJ
8232 Persistent connection support for servers.
8233 Squid uses persistent connections (when allowed). You can use
8234 this option to disable persistent connections with servers.
8d6275c0 8235DOC_END
8236
8237NAME: persistent_connection_after_error
8238TYPE: onoff
8239LOC: Config.onoff.error_pconns
0fccfb7f 8240DEFAULT: on
8d6275c0 8241DOC_START
8242 With this directive the use of persistent connections after
8243 HTTP errors can be disabled. Useful if you have clients
8244 who fail to handle errors on persistent connections proper.
8245DOC_END
8246
8247NAME: detect_broken_pconn
8248TYPE: onoff
8249LOC: Config.onoff.detect_broken_server_pconns
8250DEFAULT: off
8251DOC_START
8252 Some servers have been found to incorrectly signal the use
8253 of HTTP/1.0 persistent connections even on replies not
8254 compatible, causing significant delays. This server problem
8255 has mostly been seen on redirects.
8256
8257 By enabling this directive Squid attempts to detect such
8258 broken replies and automatically assume the reply is finished
8259 after 10 seconds timeout.
8260DOC_END
8261
8262COMMENT_START
8263 CACHE DIGEST OPTIONS
8264 -----------------------------------------------------------------------------
8265COMMENT_END
8266
8267NAME: digest_generation
8268IFDEF: USE_CACHE_DIGESTS
8269TYPE: onoff
8270LOC: Config.onoff.digest_generation
8271DEFAULT: on
8272DOC_START
8273 This controls whether the server will generate a Cache Digest
8274 of its contents. By default, Cache Digest generation is
13e917b5 8275 enabled if Squid is compiled with --enable-cache-digests defined.
8d6275c0 8276DOC_END
8277
8278NAME: digest_bits_per_entry
8279IFDEF: USE_CACHE_DIGESTS
8280TYPE: int
8281LOC: Config.digest.bits_per_entry
8282DEFAULT: 5
8283DOC_START
8284 This is the number of bits of the server's Cache Digest which
8285 will be associated with the Digest entry for a given HTTP
8286 Method and URL (public key) combination. The default is 5.
8287DOC_END
8288
8289NAME: digest_rebuild_period
8290IFDEF: USE_CACHE_DIGESTS
8291COMMENT: (seconds)
8292TYPE: time_t
8293LOC: Config.digest.rebuild_period
8294DEFAULT: 1 hour
8295DOC_START
749ceff8 8296 This is the wait time between Cache Digest rebuilds.
8d6275c0 8297DOC_END
8298
8299NAME: digest_rewrite_period
8300COMMENT: (seconds)
8301IFDEF: USE_CACHE_DIGESTS
8302TYPE: time_t
8303LOC: Config.digest.rewrite_period
8304DEFAULT: 1 hour
8305DOC_START
749ceff8 8306 This is the wait time between Cache Digest writes to
8d6275c0 8307 disk.
8308DOC_END
8309
8310NAME: digest_swapout_chunk_size
8311COMMENT: (bytes)
8312TYPE: b_size_t
8313IFDEF: USE_CACHE_DIGESTS
8314LOC: Config.digest.swapout_chunk_size
8315DEFAULT: 4096 bytes
8316DOC_START
8317 This is the number of bytes of the Cache Digest to write to
8318 disk at a time. It defaults to 4096 bytes (4KB), the Squid
8319 default swap page.
8320DOC_END
8321
8322NAME: digest_rebuild_chunk_percentage
8323COMMENT: (percent, 0-100)
8324IFDEF: USE_CACHE_DIGESTS
8325TYPE: int
8326LOC: Config.digest.rebuild_chunk_percentage
8327DEFAULT: 10
8328DOC_START
8329 This is the percentage of the Cache Digest to be scanned at a
8330 time. By default it is set to 10% of the Cache Digest.
8331DOC_END
8332
1db9eacd 8333COMMENT_START
5473c134 8334 SNMP OPTIONS
1db9eacd 8335 -----------------------------------------------------------------------------
8336COMMENT_END
8337
5473c134 8338NAME: snmp_port
ae870270 8339TYPE: u_short
5473c134 8340LOC: Config.Port.snmp
87630341 8341DEFAULT: 0
638402dd 8342DEFAULT_DOC: SNMP disabled.
5473c134 8343IFDEF: SQUID_SNMP
8d6275c0 8344DOC_START
87630341 8345 The port number where Squid listens for SNMP requests. To enable
8346 SNMP support set this to a suitable port number. Port number
8347 3401 is often used for the Squid SNMP agent. By default it's
8348 set to "0" (disabled)
e0855596
AJ
8349
8350 Example:
8351 snmp_port 3401
8d6275c0 8352DOC_END
8353
5473c134 8354NAME: snmp_access
8355TYPE: acl_access
8356LOC: Config.accessList.snmp
638402dd
AJ
8357DEFAULT: none
8358DEFAULT_DOC: Deny, unless rules exist in squid.conf.
5473c134 8359IFDEF: SQUID_SNMP
8d6275c0 8360DOC_START
5473c134 8361 Allowing or denying access to the SNMP port.
8d6275c0 8362
5473c134 8363 All access to the agent is denied by default.
8364 usage:
8d6275c0 8365
5473c134 8366 snmp_access allow|deny [!]aclname ...
8d6275c0 8367
b3567eb5
FC
8368 This clause only supports fast acl types.
8369 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
638402dd 8370
5473c134 8371Example:
8372 snmp_access allow snmppublic localhost
8373 snmp_access deny all
cccac0a2 8374DOC_END
8375
5473c134 8376NAME: snmp_incoming_address
8377TYPE: address
8378LOC: Config.Addrs.snmp_incoming
0eb08770 8379DEFAULT: any_addr
638402dd 8380DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
5473c134 8381IFDEF: SQUID_SNMP
638402dd
AJ
8382DOC_START
8383 Just like 'udp_incoming_address', but for the SNMP port.
8384
8385 snmp_incoming_address is used for the SNMP socket receiving
8386 messages from SNMP agents.
8387
8388 The default snmp_incoming_address is to listen on all
8389 available network interfaces.
8390DOC_END
df2eec10 8391
5473c134 8392NAME: snmp_outgoing_address
8393TYPE: address
8394LOC: Config.Addrs.snmp_outgoing
0eb08770 8395DEFAULT: no_addr
638402dd 8396DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
5473c134 8397IFDEF: SQUID_SNMP
cccac0a2 8398DOC_START
638402dd 8399 Just like 'udp_outgoing_address', but for the SNMP port.
cccac0a2 8400
5473c134 8401 snmp_outgoing_address is used for SNMP packets returned to SNMP
8402 agents.
cccac0a2 8403
0eb08770
HN
8404 If snmp_outgoing_address is not set it will use the same socket
8405 as snmp_incoming_address. Only change this if you want to have
8406 SNMP replies sent using another address than where this Squid
8407 listens for SNMP queries.
cccac0a2 8408
5473c134 8409 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
638402dd 8410 the same value since they both use the same port.
cccac0a2 8411DOC_END
8412
5473c134 8413COMMENT_START
8414 ICP OPTIONS
8415 -----------------------------------------------------------------------------
8416COMMENT_END
8417
8418NAME: icp_port udp_port
ae870270 8419TYPE: u_short
5473c134 8420DEFAULT: 0
638402dd 8421DEFAULT_DOC: ICP disabled.
5473c134 8422LOC: Config.Port.icp
cccac0a2 8423DOC_START
5473c134 8424 The port number where Squid sends and receives ICP queries to
8425 and from neighbor caches. The standard UDP port for ICP is 3130.
e0855596
AJ
8426
8427 Example:
8428 icp_port @DEFAULT_ICP_PORT@
cccac0a2 8429DOC_END
8430
5473c134 8431NAME: htcp_port
8432IFDEF: USE_HTCP
ae870270 8433TYPE: u_short
87630341 8434DEFAULT: 0
638402dd 8435DEFAULT_DOC: HTCP disabled.
5473c134 8436LOC: Config.Port.htcp
cccac0a2 8437DOC_START
5473c134 8438 The port number where Squid sends and receives HTCP queries to
87630341 8439 and from neighbor caches. To turn it on you want to set it to
638402dd 8440 4827.
e0855596
AJ
8441
8442 Example:
8443 htcp_port 4827
cccac0a2 8444DOC_END
8445
8446NAME: log_icp_queries
8447COMMENT: on|off
8448TYPE: onoff
8449DEFAULT: on
8450LOC: Config.onoff.log_udp
8451DOC_START
8452 If set, ICP queries are logged to access.log. You may wish
8453 do disable this if your ICP load is VERY high to speed things
8454 up or to simplify log analysis.
8455DOC_END
8456
5473c134 8457NAME: udp_incoming_address
8458TYPE: address
8459LOC:Config.Addrs.udp_incoming
0eb08770 8460DEFAULT: any_addr
638402dd 8461DEFAULT_DOC: Accept packets from all machine interfaces.
8524d4b2 8462DOC_START
8463 udp_incoming_address is used for UDP packets received from other
8464 caches.
8465
8466 The default behavior is to not bind to any specific address.
8467
8468 Only change this if you want to have all UDP queries received on
8469 a specific interface/address.
8470
8471 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
8472 modules. Altering it will affect all of them in the same manner.
8473
8474 see also; udp_outgoing_address
8475
8476 NOTE, udp_incoming_address and udp_outgoing_address can not
8477 have the same value since they both use the same port.
8478DOC_END
cccac0a2 8479
5473c134 8480NAME: udp_outgoing_address
8481TYPE: address
8482LOC: Config.Addrs.udp_outgoing
0eb08770 8483DEFAULT: no_addr
638402dd 8484DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
cccac0a2 8485DOC_START
8524d4b2 8486 udp_outgoing_address is used for UDP packets sent out to other
5473c134 8487 caches.
cccac0a2 8488
5473c134 8489 The default behavior is to not bind to any specific address.
cccac0a2 8490
8524d4b2 8491 Instead it will use the same socket as udp_incoming_address.
8492 Only change this if you want to have UDP queries sent using another
8493 address than where this Squid listens for UDP queries from other
5473c134 8494 caches.
8495
8524d4b2 8496 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
8497 modules. Altering it will affect all of them in the same manner.
8498
8499 see also; udp_incoming_address
8500
5473c134 8501 NOTE, udp_incoming_address and udp_outgoing_address can not
8524d4b2 8502 have the same value since they both use the same port.
cccac0a2 8503DOC_END
8504
3d1e3e43 8505NAME: icp_hit_stale
8506COMMENT: on|off
8507TYPE: onoff
8508DEFAULT: off
8509LOC: Config.onoff.icp_hit_stale
8510DOC_START
8511 If you want to return ICP_HIT for stale cache objects, set this
8512 option to 'on'. If you have sibling relationships with caches
8513 in other administrative domains, this should be 'off'. If you only
8514 have sibling relationships with caches under your control,
8515 it is probably okay to set this to 'on'.
8516 If set to 'on', your siblings should use the option "allow-miss"
8517 on their cache_peer lines for connecting to you.
8518DOC_END
8519
5473c134 8520NAME: minimum_direct_hops
cccac0a2 8521TYPE: int
5473c134 8522DEFAULT: 4
8523LOC: Config.minDirectHops
cccac0a2 8524DOC_START
5473c134 8525 If using the ICMP pinging stuff, do direct fetches for sites
8526 which are no more than this many hops away.
cccac0a2 8527DOC_END
8528
5473c134 8529NAME: minimum_direct_rtt
638402dd 8530COMMENT: (msec)
5473c134 8531TYPE: int
8532DEFAULT: 400
8533LOC: Config.minDirectRtt
cccac0a2 8534DOC_START
5473c134 8535 If using the ICMP pinging stuff, do direct fetches for sites
8536 which are no more than this many rtt milliseconds away.
cccac0a2 8537DOC_END
8538
cccac0a2 8539NAME: netdb_low
8540TYPE: int
8541DEFAULT: 900
8542LOC: Config.Netdb.low
638402dd
AJ
8543DOC_START
8544 The low water mark for the ICMP measurement database.
8545
8546 Note: high watermark controlled by netdb_high directive.
8547
8548 These watermarks are counts, not percents. The defaults are
8549 (low) 900 and (high) 1000. When the high water mark is
8550 reached, database entries will be deleted until the low
8551 mark is reached.
8552DOC_END
cccac0a2 8553
8554NAME: netdb_high
8555TYPE: int
8556DEFAULT: 1000
8557LOC: Config.Netdb.high
8558DOC_START
638402dd
AJ
8559 The high water mark for the ICMP measurement database.
8560
8561 Note: low watermark controlled by netdb_low directive.
8562
8563 These watermarks are counts, not percents. The defaults are
8564 (low) 900 and (high) 1000. When the high water mark is
8565 reached, database entries will be deleted until the low
8566 mark is reached.
cccac0a2 8567DOC_END
8568
cccac0a2 8569NAME: netdb_ping_period
8570TYPE: time_t
8571LOC: Config.Netdb.period
8572DEFAULT: 5 minutes
8573DOC_START
8574 The minimum period for measuring a site. There will be at
8575 least this much delay between successive pings to the same
8576 network. The default is five minutes.
8577DOC_END
8578
cccac0a2 8579NAME: query_icmp
8580COMMENT: on|off
8581TYPE: onoff
8582DEFAULT: off
8583LOC: Config.onoff.query_icmp
8584DOC_START
8585 If you want to ask your peers to include ICMP data in their ICP
8586 replies, enable this option.
8587
8588 If your peer has configured Squid (during compilation) with
7f7db318 8589 '--enable-icmp' that peer will send ICMP pings to origin server
8590 sites of the URLs it receives. If you enable this option the
cccac0a2 8591 ICP replies from that peer will include the ICMP data (if available).
8592 Then, when choosing a parent cache, Squid will choose the parent with
8593 the minimal RTT to the origin server. When this happens, the
8594 hierarchy field of the access.log will be
8595 "CLOSEST_PARENT_MISS". This option is off by default.
8596DOC_END
8597
8598NAME: test_reachability
8599COMMENT: on|off
8600TYPE: onoff
8601DEFAULT: off
8602LOC: Config.onoff.test_reachability
8603DOC_START
8604 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
8605 instead of ICP_MISS if the target host is NOT in the ICMP
8606 database, or has a zero RTT.
8607DOC_END
8608
5473c134 8609NAME: icp_query_timeout
8610COMMENT: (msec)
8611DEFAULT: 0
638402dd 8612DEFAULT_DOC: Dynamic detection.
5473c134 8613TYPE: int
8614LOC: Config.Timeout.icp_query
4c3ef9b2 8615DOC_START
5473c134 8616 Normally Squid will automatically determine an optimal ICP
8617 query timeout value based on the round-trip-time of recent ICP
8618 queries. If you want to override the value determined by
8619 Squid, set this 'icp_query_timeout' to a non-zero value. This
8620 value is specified in MILLISECONDS, so, to use a 2-second
8621 timeout (the old default), you would write:
4c3ef9b2 8622
5473c134 8623 icp_query_timeout 2000
4c3ef9b2 8624DOC_END
8625
5473c134 8626NAME: maximum_icp_query_timeout
8627COMMENT: (msec)
8628DEFAULT: 2000
8629TYPE: int
8630LOC: Config.Timeout.icp_query_max
cccac0a2 8631DOC_START
5473c134 8632 Normally the ICP query timeout is determined dynamically. But
8633 sometimes it can lead to very large values (say 5 seconds).
8634 Use this option to put an upper limit on the dynamic timeout
8635 value. Do NOT use this option to always use a fixed (instead
8636 of a dynamic) timeout value. To set a fixed timeout see the
8637 'icp_query_timeout' directive.
cccac0a2 8638DOC_END
8639
5473c134 8640NAME: minimum_icp_query_timeout
8641COMMENT: (msec)
8642DEFAULT: 5
8643TYPE: int
8644LOC: Config.Timeout.icp_query_min
cccac0a2 8645DOC_START
5473c134 8646 Normally the ICP query timeout is determined dynamically. But
8647 sometimes it can lead to very small timeouts, even lower than
8648 the normal latency variance on your link due to traffic.
8649 Use this option to put an lower limit on the dynamic timeout
8650 value. Do NOT use this option to always use a fixed (instead
8651 of a dynamic) timeout value. To set a fixed timeout see the
8652 'icp_query_timeout' directive.
cccac0a2 8653DOC_END
8654
5473c134 8655NAME: background_ping_rate
8656COMMENT: time-units
8657TYPE: time_t
8658DEFAULT: 10 seconds
8659LOC: Config.backgroundPingRate
cccac0a2 8660DOC_START
5473c134 8661 Controls how often the ICP pings are sent to siblings that
8662 have background-ping set.
cccac0a2 8663DOC_END
8664
5473c134 8665COMMENT_START
8666 MULTICAST ICP OPTIONS
8667 -----------------------------------------------------------------------------
8668COMMENT_END
8669
8670NAME: mcast_groups
8671TYPE: wordlist
8672LOC: Config.mcast_group_list
8c01ada0 8673DEFAULT: none
8674DOC_START
5473c134 8675 This tag specifies a list of multicast groups which your server
8676 should join to receive multicasted ICP queries.
8c01ada0 8677
5473c134 8678 NOTE! Be very careful what you put here! Be sure you
8679 understand the difference between an ICP _query_ and an ICP
8680 _reply_. This option is to be set only if you want to RECEIVE
8681 multicast queries. Do NOT set this option to SEND multicast
8682 ICP (use cache_peer for that). ICP replies are always sent via
8683 unicast, so this option does not affect whether or not you will
8684 receive replies from multicast group members.
8c01ada0 8685
5473c134 8686 You must be very careful to NOT use a multicast address which
8687 is already in use by another group of caches.
8c01ada0 8688
5473c134 8689 If you are unsure about multicast, please read the Multicast
8690 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
8c01ada0 8691
5473c134 8692 Usage: mcast_groups 239.128.16.128 224.0.1.20
8c01ada0 8693
5473c134 8694 By default, Squid doesn't listen on any multicast groups.
8695DOC_END
8c01ada0 8696
5473c134 8697NAME: mcast_miss_addr
8698IFDEF: MULTICAST_MISS_STREAM
8699TYPE: address
8700LOC: Config.mcast_miss.addr
0eb08770 8701DEFAULT: no_addr
638402dd 8702DEFAULT_DOC: disabled.
5473c134 8703DOC_START
8704 If you enable this option, every "cache miss" URL will
8705 be sent out on the specified multicast address.
cccac0a2 8706
5473c134 8707 Do not enable this option unless you are are absolutely
8708 certain you understand what you are doing.
cccac0a2 8709DOC_END
8710
5473c134 8711NAME: mcast_miss_ttl
8712IFDEF: MULTICAST_MISS_STREAM
ae870270 8713TYPE: u_short
5473c134 8714LOC: Config.mcast_miss.ttl
8715DEFAULT: 16
cccac0a2 8716DOC_START
5473c134 8717 This is the time-to-live value for packets multicasted
8718 when multicasting off cache miss URLs is enabled. By
8719 default this is set to 'site scope', i.e. 16.
8720DOC_END
cccac0a2 8721
5473c134 8722NAME: mcast_miss_port
8723IFDEF: MULTICAST_MISS_STREAM
ae870270 8724TYPE: u_short
5473c134 8725LOC: Config.mcast_miss.port
8726DEFAULT: 3135
8727DOC_START
8728 This is the port number to be used in conjunction with
8729 'mcast_miss_addr'.
8730DOC_END
cccac0a2 8731
5473c134 8732NAME: mcast_miss_encode_key
8733IFDEF: MULTICAST_MISS_STREAM
8734TYPE: string
8735LOC: Config.mcast_miss.encode_key
8736DEFAULT: XXXXXXXXXXXXXXXX
8737DOC_START
8738 The URLs that are sent in the multicast miss stream are
8739 encrypted. This is the encryption key.
8740DOC_END
8c01ada0 8741
5473c134 8742NAME: mcast_icp_query_timeout
8743COMMENT: (msec)
8744DEFAULT: 2000
8745TYPE: int
8746LOC: Config.Timeout.mcast_icp_query
8747DOC_START
8748 For multicast peers, Squid regularly sends out ICP "probes" to
8749 count how many other peers are listening on the given multicast
8750 address. This value specifies how long Squid should wait to
8751 count all the replies. The default is 2000 msec, or 2
8752 seconds.
cccac0a2 8753DOC_END
8754
5473c134 8755COMMENT_START
8756 INTERNAL ICON OPTIONS
8757 -----------------------------------------------------------------------------
8758COMMENT_END
8759
cccac0a2 8760NAME: icon_directory
8761TYPE: string
8762LOC: Config.icons.directory
8763DEFAULT: @DEFAULT_ICON_DIR@
8764DOC_START
8765 Where the icons are stored. These are normally kept in
8766 @DEFAULT_ICON_DIR@
8767DOC_END
8768
f024c970 8769NAME: global_internal_static
8770TYPE: onoff
8771LOC: Config.onoff.global_internal_static
8772DEFAULT: on
8773DOC_START
8774 This directive controls is Squid should intercept all requests for
8775 /squid-internal-static/ no matter which host the URL is requesting
8776 (default on setting), or if nothing special should be done for
8777 such URLs (off setting). The purpose of this directive is to make
8778 icons etc work better in complex cache hierarchies where it may
8779 not always be possible for all corners in the cache mesh to reach
8780 the server generating a directory listing.
8781DOC_END
8782
5473c134 8783NAME: short_icon_urls
8784TYPE: onoff
8785LOC: Config.icons.use_short_names
8786DEFAULT: on
8787DOC_START
8788 If this is enabled Squid will use short URLs for icons.
8789 If disabled it will revert to the old behavior of including
8790 it's own name and port in the URL.
8791
8792 If you run a complex cache hierarchy with a mix of Squid and
8793 other proxies you may need to disable this directive.
8794DOC_END
8795
8796COMMENT_START
8797 ERROR PAGE OPTIONS
8798 -----------------------------------------------------------------------------
8799COMMENT_END
8800
8801NAME: error_directory
8802TYPE: string
8803LOC: Config.errorDirectory
43000484 8804DEFAULT: none
638402dd 8805DEFAULT_DOC: Send error pages in the clients preferred language
5473c134 8806DOC_START
8807 If you wish to create your own versions of the default
43000484
AJ
8808 error files to customize them to suit your company copy
8809 the error/template files to another directory and point
8810 this tag at them.
8811
8812 WARNING: This option will disable multi-language support
8813 on error pages if used.
5473c134 8814
8815 The squid developers are interested in making squid available in
8816 a wide variety of languages. If you are making translations for a
43000484 8817 language that Squid does not currently provide please consider
5473c134 8818 contributing your translation back to the project.
43000484
AJ
8819 http://wiki.squid-cache.org/Translations
8820
8821 The squid developers working on translations are happy to supply drop-in
8822 translated error files in exchange for any new language contributions.
8823DOC_END
8824
8825NAME: error_default_language
8826IFDEF: USE_ERR_LOCALES
8827TYPE: string
8828LOC: Config.errorDefaultLanguage
8829DEFAULT: none
638402dd 8830DEFAULT_DOC: Generate English language pages.
43000484
AJ
8831DOC_START
8832 Set the default language which squid will send error pages in
8833 if no existing translation matches the clients language
8834 preferences.
8835
8836 If unset (default) generic English will be used.
8837
8838 The squid developers are interested in making squid available in
8839 a wide variety of languages. If you are interested in making
8840 translations for any language see the squid wiki for details.
8841 http://wiki.squid-cache.org/Translations
5473c134 8842DOC_END
8843
c411820c
AJ
8844NAME: error_log_languages
8845IFDEF: USE_ERR_LOCALES
8846TYPE: onoff
8847LOC: Config.errorLogMissingLanguages
8848DEFAULT: on
8849DOC_START
8850 Log to cache.log what languages users are attempting to
8851 auto-negotiate for translations.
8852
8853 Successful negotiations are not logged. Only failures
8854 have meaning to indicate that Squid may need an upgrade
0c49f10e 8855 of its error page translations.
c411820c
AJ
8856DOC_END
8857
5b52cb6c
AJ
8858NAME: err_page_stylesheet
8859TYPE: string
8860LOC: Config.errorStylesheet
8861DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
8862DOC_START
8863 CSS Stylesheet to pattern the display of Squid default error pages.
8864
8865 For information on CSS see http://www.w3.org/Style/CSS/
8866DOC_END
8867
5473c134 8868NAME: err_html_text
8869TYPE: eol
8870LOC: Config.errHtmlText
8871DEFAULT: none
8872DOC_START
8873 HTML text to include in error messages. Make this a "mailto"
8874 URL to your admin address, or maybe just a link to your
8875 organizations Web page.
8876
8877 To include this in your error messages, you must rewrite
8878 the error template files (found in the "errors" directory).
8879 Wherever you want the 'err_html_text' line to appear,
8880 insert a %L tag in the error template file.
8881DOC_END
8882
8883NAME: email_err_data
8884COMMENT: on|off
8885TYPE: onoff
8886LOC: Config.onoff.emailErrData
8887DEFAULT: on
8888DOC_START
8889 If enabled, information about the occurred error will be
8890 included in the mailto links of the ERR pages (if %W is set)
8891 so that the email body contains the data.
8892 Syntax is <A HREF="mailto:%w%W">%w</A>
8893DOC_END
8894
8895NAME: deny_info
8896TYPE: denyinfo
8897LOC: Config.denyInfoList
8898DEFAULT: none
8899DOC_START
8900 Usage: deny_info err_page_name acl
8901 or deny_info http://... acl
43000484 8902 or deny_info TCP_RESET acl
5473c134 8903
8904 This can be used to return a ERR_ page for requests which
8905 do not pass the 'http_access' rules. Squid remembers the last
8906 acl it evaluated in http_access, and if a 'deny_info' line exists
8907 for that ACL Squid returns a corresponding error page.
8908
8909 The acl is typically the last acl on the http_access deny line which
8910 denied access. The exceptions to this rule are:
8911 - When Squid needs to request authentication credentials. It's then
8912 the first authentication related acl encountered
8913 - When none of the http_access lines matches. It's then the last
8914 acl processed on the last http_access line.
3af10ac0
AR
8915 - When the decision to deny access was made by an adaptation service,
8916 the acl name is the corresponding eCAP or ICAP service_name.
5473c134 8917
43000484
AJ
8918 NP: If providing your own custom error pages with error_directory
8919 you may also specify them by your custom file name:
8920 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
5473c134 8921
2f8abb64 8922 By default Squid will send "403 Forbidden". A different 4xx or 5xx
aed9a15b
AJ
8923 may be specified by prefixing the file name with the code and a colon.
8924 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
8925
5473c134 8926 Alternatively you can tell Squid to reset the TCP connection
8927 by specifying TCP_RESET.
15b02e9a
AJ
8928
8929 Or you can specify an error URL or URL pattern. The browsers will
aed9a15b
AJ
8930 get redirected to the specified URL after formatting tags have
8931 been replaced. Redirect will be done with 302 or 307 according to
8932 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
8933 the URL. e.g. 303:http://example.com/
15b02e9a
AJ
8934
8935 URL FORMAT TAGS:
8936 %a - username (if available. Password NOT included)
ea35939b 8937 %A - Local listening IP address the client connection was connected to
15b02e9a
AJ
8938 %B - FTP path URL
8939 %e - Error number
8940 %E - Error description
8941 %h - Squid hostname
8942 %H - Request domain name
8943 %i - Client IP Address
8944 %M - Request Method
05dbf66c 8945 %O - Unescaped message result from external ACL helper
15b02e9a
AJ
8946 %o - Message result from external ACL helper
8947 %p - Request Port number
8948 %P - Request Protocol name
8949 %R - Request URL path
8950 %T - Timestamp in RFC 1123 format
8951 %U - Full canonical URL from client
8952 (HTTPS URLs terminate with *)
8953 %u - Full canonical URL from client
8954 %w - Admin email from squid.conf
e4a8468d 8955 %x - Error name
15b02e9a
AJ
8956 %% - Literal percent (%) code
8957
5473c134 8958DOC_END
8959
8960COMMENT_START
9603207d 8961 OPTIONS INFLUENCING REQUEST FORWARDING
5473c134 8962 -----------------------------------------------------------------------------
8963COMMENT_END
8964
8965NAME: nonhierarchical_direct
e72a0ec0 8966TYPE: onoff
5473c134 8967LOC: Config.onoff.nonhierarchical_direct
e72a0ec0 8968DEFAULT: on
8969DOC_START
5473c134 8970 By default, Squid will send any non-hierarchical requests
9967aef6 8971 (not cacheable request type) direct to origin servers.
e72a0ec0 8972
638402dd 8973 When this is set to "off", Squid will prefer to send these
5473c134 8974 requests to parents.
0b0cfcf2 8975
5473c134 8976 Note that in most configurations, by turning this off you will only
8977 add latency to these request without any improvement in global hit
8978 ratio.
0b0cfcf2 8979
638402dd
AJ
8980 This option only sets a preference. If the parent is unavailable a
8981 direct connection to the origin server may still be attempted. To
8982 completely prevent direct connections use never_direct.
8d6275c0 8983DOC_END
0b0cfcf2 8984
5473c134 8985NAME: prefer_direct
8d6275c0 8986TYPE: onoff
5473c134 8987LOC: Config.onoff.prefer_direct
8d6275c0 8988DEFAULT: off
8989DOC_START
5473c134 8990 Normally Squid tries to use parents for most requests. If you for some
8991 reason like it to first try going direct and only use a parent if
8992 going direct fails set this to on.
0b0cfcf2 8993
5473c134 8994 By combining nonhierarchical_direct off and prefer_direct on you
8995 can set up Squid to use a parent as a backup path if going direct
8996 fails.
8997
8998 Note: If you want Squid to use parents for all requests see
8999 the never_direct directive. prefer_direct only modifies how Squid
9000 acts on cacheable requests.
cccac0a2 9001DOC_END
9002
96598f93
AJ
9003NAME: cache_miss_revalidate
9004COMMENT: on|off
9005TYPE: onoff
9006DEFAULT: on
9007LOC: Config.onoff.cache_miss_revalidate
9008DOC_START
2d4eefd9
AJ
9009 RFC 7232 defines a conditional request mechanism to prevent
9010 response objects being unnecessarily transferred over the network.
9011 If that mechanism is used by the client and a cache MISS occurs
9012 it can prevent new cache entries being created.
9013
9014 This option determines whether Squid on cache MISS will pass the
9015 client revalidation request to the server or tries to fetch new
9016 content for caching. It can be useful while the cache is mostly
9017 empty to more quickly have the cache populated by generating
9018 non-conditional GETs.
96598f93
AJ
9019
9020 When set to 'on' (default), Squid will pass all client If-* headers
2d4eefd9
AJ
9021 to the server. This permits server responses without a cacheable
9022 payload to be delivered and on MISS no new cache entry is created.
96598f93
AJ
9023
9024 When set to 'off' and if the request is cacheable, Squid will
9025 remove the clients If-Modified-Since and If-None-Match headers from
2d4eefd9
AJ
9026 the request sent to the server. This requests a 200 status response
9027 from the server to create a new cache entry with.
96598f93
AJ
9028DOC_END
9029
5473c134 9030NAME: always_direct
8d6275c0 9031TYPE: acl_access
5473c134 9032LOC: Config.accessList.AlwaysDirect
0b0cfcf2 9033DEFAULT: none
638402dd 9034DEFAULT_DOC: Prevent any cache_peer being used for this request.
0b0cfcf2 9035DOC_START
5473c134 9036 Usage: always_direct allow|deny [!]aclname ...
0b0cfcf2 9037
5473c134 9038 Here you can use ACL elements to specify requests which should
9039 ALWAYS be forwarded by Squid to the origin servers without using
9040 any peers. For example, to always directly forward requests for
9041 local servers ignoring any parents or siblings you may have use
9042 something like:
0b0cfcf2 9043
5473c134 9044 acl local-servers dstdomain my.domain.net
9045 always_direct allow local-servers
0b0cfcf2 9046
5473c134 9047 To always forward FTP requests directly, use
f16fbc82 9048
5473c134 9049 acl FTP proto FTP
9050 always_direct allow FTP
cccac0a2 9051
5473c134 9052 NOTE: There is a similar, but opposite option named
9053 'never_direct'. You need to be aware that "always_direct deny
9054 foo" is NOT the same thing as "never_direct allow foo". You
9055 may need to use a deny rule to exclude a more-specific case of
9056 some other rule. Example:
8d6275c0 9057
5473c134 9058 acl local-external dstdomain external.foo.net
9059 acl local-servers dstdomain .foo.net
9060 always_direct deny local-external
9061 always_direct allow local-servers
8d6275c0 9062
5473c134 9063 NOTE: If your goal is to make the client forward the request
9064 directly to the origin server bypassing Squid then this needs
9065 to be done in the client configuration. Squid configuration
9066 can only tell Squid how Squid should fetch the object.
8d6275c0 9067
5473c134 9068 NOTE: This directive is not related to caching. The replies
9069 is cached as usual even if you use always_direct. To not cache
b3567eb5 9070 the replies see the 'cache' directive.
5473c134 9071
b3567eb5
FC
9072 This clause supports both fast and slow acl types.
9073 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 9074DOC_END
0976f8db 9075
5473c134 9076NAME: never_direct
9077TYPE: acl_access
9078LOC: Config.accessList.NeverDirect
9079DEFAULT: none
638402dd 9080DEFAULT_DOC: Allow DNS results to be used for this request.
8d6275c0 9081DOC_START
5473c134 9082 Usage: never_direct allow|deny [!]aclname ...
9083
9084 never_direct is the opposite of always_direct. Please read
9085 the description for always_direct if you have not already.
9086
9087 With 'never_direct' you can use ACL elements to specify
9088 requests which should NEVER be forwarded directly to origin
9089 servers. For example, to force the use of a proxy for all
9090 requests, except those in your local domain use something like:
9091
9092 acl local-servers dstdomain .foo.net
5473c134 9093 never_direct deny local-servers
9094 never_direct allow all
9095
9096 or if Squid is inside a firewall and there are local intranet
9097 servers inside the firewall use something like:
9098
9099 acl local-intranet dstdomain .foo.net
9100 acl local-external dstdomain external.foo.net
9101 always_direct deny local-external
9102 always_direct allow local-intranet
9103 never_direct allow all
9104
b3567eb5
FC
9105 This clause supports both fast and slow acl types.
9106 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
8d6275c0 9107DOC_END
0976f8db 9108
5473c134 9109COMMENT_START
9110 ADVANCED NETWORKING OPTIONS
9111 -----------------------------------------------------------------------------
9112COMMENT_END
9113
65d448bc 9114NAME: incoming_udp_average incoming_icp_average
cccac0a2 9115TYPE: int
9116DEFAULT: 6
65d448bc
AJ
9117LOC: Config.comm_incoming.udp.average
9118DOC_START
9119 Heavy voodoo here. I can't even believe you are reading this.
9120 Are you crazy? Don't even think about adjusting these unless
9121 you understand the algorithms in comm_select.c first!
9122DOC_END
cccac0a2 9123
65d448bc 9124NAME: incoming_tcp_average incoming_http_average
cccac0a2 9125TYPE: int
9126DEFAULT: 4
65d448bc
AJ
9127LOC: Config.comm_incoming.tcp.average
9128DOC_START
9129 Heavy voodoo here. I can't even believe you are reading this.
9130 Are you crazy? Don't even think about adjusting these unless
9131 you understand the algorithms in comm_select.c first!
9132DOC_END
cccac0a2 9133
9134NAME: incoming_dns_average
9135TYPE: int
9136DEFAULT: 4
65d448bc
AJ
9137LOC: Config.comm_incoming.dns.average
9138DOC_START
9139 Heavy voodoo here. I can't even believe you are reading this.
9140 Are you crazy? Don't even think about adjusting these unless
9141 you understand the algorithms in comm_select.c first!
9142DOC_END
cccac0a2 9143
65d448bc 9144NAME: min_udp_poll_cnt min_icp_poll_cnt
cccac0a2 9145TYPE: int
9146DEFAULT: 8
65d448bc
AJ
9147LOC: Config.comm_incoming.udp.min_poll
9148DOC_START
9149 Heavy voodoo here. I can't even believe you are reading this.
9150 Are you crazy? Don't even think about adjusting these unless
9151 you understand the algorithms in comm_select.c first!
9152DOC_END
cccac0a2 9153
9154NAME: min_dns_poll_cnt
9155TYPE: int
9156DEFAULT: 8
65d448bc
AJ
9157LOC: Config.comm_incoming.dns.min_poll
9158DOC_START
9159 Heavy voodoo here. I can't even believe you are reading this.
9160 Are you crazy? Don't even think about adjusting these unless
9161 you understand the algorithms in comm_select.c first!
9162DOC_END
cccac0a2 9163
65d448bc 9164NAME: min_tcp_poll_cnt min_http_poll_cnt
cccac0a2 9165TYPE: int
9166DEFAULT: 8
65d448bc 9167LOC: Config.comm_incoming.tcp.min_poll
cccac0a2 9168DOC_START
5473c134 9169 Heavy voodoo here. I can't even believe you are reading this.
9170 Are you crazy? Don't even think about adjusting these unless
9171 you understand the algorithms in comm_select.c first!
9172DOC_END
9173
9174NAME: accept_filter
5473c134 9175TYPE: string
9176DEFAULT: none
9177LOC: Config.accept_filter
9178DOC_START
0b4d4be5 9179 FreeBSD:
9180
5473c134 9181 The name of an accept(2) filter to install on Squid's
9182 listen socket(s). This feature is perhaps specific to
9183 FreeBSD and requires support in the kernel.
9184
9185 The 'httpready' filter delays delivering new connections
2324cda2 9186 to Squid until a full HTTP request has been received.
0b4d4be5 9187 See the accf_http(9) man page for details.
9188
9189 The 'dataready' filter delays delivering new connections
9190 to Squid until there is some data to process.
9191 See the accf_dataready(9) man page for details.
9192
9193 Linux:
9603207d 9194
0b4d4be5 9195 The 'data' filter delays delivering of new connections
9196 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
9197 You may optionally specify a number of seconds to wait by
9198 'data=N' where N is the number of seconds. Defaults to 30
9199 if not specified. See the tcp(7) man page for details.
5473c134 9200EXAMPLE:
0b4d4be5 9201# FreeBSD
5473c134 9202accept_filter httpready
0b4d4be5 9203# Linux
9204accept_filter data
5473c134 9205DOC_END
9206
ab2ecb0e
AJ
9207NAME: client_ip_max_connections
9208TYPE: int
9209LOC: Config.client_ip_max_connections
9210DEFAULT: -1
638402dd 9211DEFAULT_DOC: No limit.
ab2ecb0e
AJ
9212DOC_START
9213 Set an absolute limit on the number of connections a single
9214 client IP can use. Any more than this and Squid will begin to drop
9215 new connections from the client until it closes some links.
9216
6ea12e8f 9217 Note that this is a global limit. It affects all HTTP, HTCP, and FTP
ab2ecb0e
AJ
9218 connections from the client. For finer control use the ACL access controls.
9219
9220 Requires client_db to be enabled (the default).
9221
2f8abb64 9222 WARNING: This may noticeably slow down traffic received via external proxies
ab2ecb0e
AJ
9223 or NAT devices and cause them to rebound error messages back to their clients.
9224DOC_END
9225
5473c134 9226NAME: tcp_recv_bufsize
9227COMMENT: (bytes)
9228TYPE: b_size_t
9229DEFAULT: 0 bytes
638402dd 9230DEFAULT_DOC: Use operating system TCP defaults.
5473c134 9231LOC: Config.tcpRcvBufsz
9232DOC_START
9233 Size of receive buffer to set for TCP sockets. Probably just
638402dd
AJ
9234 as easy to change your kernel's default.
9235 Omit from squid.conf to use the default buffer size.
5473c134 9236DOC_END
9237
9238COMMENT_START
9239 ICAP OPTIONS
9240 -----------------------------------------------------------------------------
9241COMMENT_END
9242
9243NAME: icap_enable
9244TYPE: onoff
9245IFDEF: ICAP_CLIENT
9246COMMENT: on|off
26cc52cb 9247LOC: Adaptation::Icap::TheConfig.onoff
5473c134 9248DEFAULT: off
9249DOC_START
53e738c6 9250 If you want to enable the ICAP module support, set this to on.
5473c134 9251DOC_END
9252
9253NAME: icap_connect_timeout
9254TYPE: time_t
9255DEFAULT: none
26cc52cb 9256LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
5473c134 9257IFDEF: ICAP_CLIENT
9258DOC_START
9259 This parameter specifies how long to wait for the TCP connect to
9260 the requested ICAP server to complete before giving up and either
9261 terminating the HTTP transaction or bypassing the failure.
9262
9263 The default for optional services is peer_connect_timeout.
9264 The default for essential services is connect_timeout.
9265 If this option is explicitly set, its value applies to all services.
9266DOC_END
9267
9268NAME: icap_io_timeout
9269COMMENT: time-units
9270TYPE: time_t
9271DEFAULT: none
638402dd 9272DEFAULT_DOC: Use read_timeout.
26cc52cb 9273LOC: Adaptation::Icap::TheConfig.io_timeout_raw
5473c134 9274IFDEF: ICAP_CLIENT
9275DOC_START
9276 This parameter specifies how long to wait for an I/O activity on
9277 an established, active ICAP connection before giving up and
9278 either terminating the HTTP transaction or bypassing the
9279 failure.
5473c134 9280DOC_END
9281
9282NAME: icap_service_failure_limit
8277060a
CT
9283COMMENT: limit [in memory-depth time-units]
9284TYPE: icap_service_failure_limit
5473c134 9285IFDEF: ICAP_CLIENT
8277060a 9286LOC: Adaptation::Icap::TheConfig
5473c134 9287DEFAULT: 10
9288DOC_START
9289 The limit specifies the number of failures that Squid tolerates
9290 when establishing a new TCP connection with an ICAP service. If
9291 the number of failures exceeds the limit, the ICAP service is
9292 not used for new ICAP requests until it is time to refresh its
8277060a 9293 OPTIONS.
5473c134 9294
9295 A negative value disables the limit. Without the limit, an ICAP
9296 service will not be considered down due to connectivity failures
9297 between ICAP OPTIONS requests.
8277060a
CT
9298
9299 Squid forgets ICAP service failures older than the specified
9603207d 9300 value of memory-depth. The memory fading algorithm
9301 is approximate because Squid does not remember individual
8277060a
CT
9302 errors but groups them instead, splitting the option
9303 value into ten time slots of equal length.
9304
9603207d 9305 When memory-depth is 0 and by default this option has no
8277060a
CT
9306 effect on service failure expiration.
9307
9308 Squid always forgets failures when updating service settings
9309 using an ICAP OPTIONS transaction, regardless of this option
9310 setting.
9311
9312 For example,
9313 # suspend service usage after 10 failures in 5 seconds:
9314 icap_service_failure_limit 10 in 5 seconds
cccac0a2 9315DOC_END
9316
5473c134 9317NAME: icap_service_revival_delay
cccac0a2 9318TYPE: int
5473c134 9319IFDEF: ICAP_CLIENT
26cc52cb 9320LOC: Adaptation::Icap::TheConfig.service_revival_delay
5473c134 9321DEFAULT: 180
cccac0a2 9322DOC_START
5473c134 9323 The delay specifies the number of seconds to wait after an ICAP
9324 OPTIONS request failure before requesting the options again. The
9325 failed ICAP service is considered "down" until fresh OPTIONS are
9326 fetched.
cccac0a2 9327
5473c134 9328 The actual delay cannot be smaller than the hardcoded minimum
9329 delay of 30 seconds.
cccac0a2 9330DOC_END
9331
5473c134 9332NAME: icap_preview_enable
cccac0a2 9333TYPE: onoff
5473c134 9334IFDEF: ICAP_CLIENT
9335COMMENT: on|off
26cc52cb 9336LOC: Adaptation::Icap::TheConfig.preview_enable
ac7a62f9 9337DEFAULT: on
cccac0a2 9338DOC_START
ac7a62f9 9339 The ICAP Preview feature allows the ICAP server to handle the
9340 HTTP message by looking only at the beginning of the message body
9603207d 9341 or even without receiving the body at all. In some environments,
ac7a62f9 9342 previews greatly speedup ICAP processing.
9343
9344 During an ICAP OPTIONS transaction, the server may tell Squid what
9345 HTTP messages should be previewed and how big the preview should be.
9346 Squid will not use Preview if the server did not request one.
9347
9348 To disable ICAP Preview for all ICAP services, regardless of
9349 individual ICAP server OPTIONS responses, set this option to "off".
9350Example:
9351icap_preview_enable off
cccac0a2 9352DOC_END
9353
5473c134 9354NAME: icap_preview_size
9355TYPE: int
9356IFDEF: ICAP_CLIENT
26cc52cb 9357LOC: Adaptation::Icap::TheConfig.preview_size
5473c134 9358DEFAULT: -1
638402dd 9359DEFAULT_DOC: No preview sent.
cccac0a2 9360DOC_START
53e738c6 9361 The default size of preview data to be sent to the ICAP server.
638402dd 9362 This value might be overwritten on a per server basis by OPTIONS requests.
cccac0a2 9363DOC_END
9364
83c51da9
CT
9365NAME: icap_206_enable
9366TYPE: onoff
9367IFDEF: ICAP_CLIENT
9368COMMENT: on|off
9369LOC: Adaptation::Icap::TheConfig.allow206_enable
9370DEFAULT: on
9371DOC_START
9372 206 (Partial Content) responses is an ICAP extension that allows the
9373 ICAP agents to optionally combine adapted and original HTTP message
9374 content. The decision to combine is postponed until the end of the
9375 ICAP response. Squid supports Partial Content extension by default.
9376
9377 Activation of the Partial Content extension is negotiated with each
9378 ICAP service during OPTIONS exchange. Most ICAP servers should handle
2f8abb64 9379 negotiation correctly even if they do not support the extension, but
83c51da9
CT
9380 some might fail. To disable Partial Content support for all ICAP
9381 services and to avoid any negotiation, set this option to "off".
9382
9383 Example:
9384 icap_206_enable off
9385DOC_END
9386
5473c134 9387NAME: icap_default_options_ttl
9388TYPE: int
9389IFDEF: ICAP_CLIENT
26cc52cb 9390LOC: Adaptation::Icap::TheConfig.default_options_ttl
5473c134 9391DEFAULT: 60
cccac0a2 9392DOC_START
53e738c6 9393 The default TTL value for ICAP OPTIONS responses that don't have
5473c134 9394 an Options-TTL header.
cccac0a2 9395DOC_END
9396
5473c134 9397NAME: icap_persistent_connections
9398TYPE: onoff
9399IFDEF: ICAP_CLIENT
9400COMMENT: on|off
26cc52cb 9401LOC: Adaptation::Icap::TheConfig.reuse_connections
5473c134 9402DEFAULT: on
cccac0a2 9403DOC_START
5473c134 9404 Whether or not Squid should use persistent connections to
9405 an ICAP server.
cccac0a2 9406DOC_END
9407
22fff3bf 9408NAME: adaptation_send_client_ip icap_send_client_ip
5473c134 9409TYPE: onoff
22fff3bf 9410IFDEF: USE_ADAPTATION
5473c134 9411COMMENT: on|off
22fff3bf 9412LOC: Adaptation::Config::send_client_ip
5473c134 9413DEFAULT: off
cccac0a2 9414DOC_START
ea3ae478
AR
9415 If enabled, Squid shares HTTP client IP information with adaptation
9416 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
9417 For eCAP, Squid sets the libecap::metaClientIp transaction option.
9418
9419 See also: adaptation_uses_indirect_client
cccac0a2 9420DOC_END
9421
22fff3bf 9422NAME: adaptation_send_username icap_send_client_username
5473c134 9423TYPE: onoff
22fff3bf 9424IFDEF: USE_ADAPTATION
5473c134 9425COMMENT: on|off
22fff3bf 9426LOC: Adaptation::Config::send_username
5473c134 9427DEFAULT: off
cccac0a2 9428DOC_START
5473c134 9429 This sends authenticated HTTP client username (if available) to
22fff3bf
AR
9430 the adaptation service.
9431
9432 For ICAP, the username value is encoded based on the
5473c134 9433 icap_client_username_encode option and is sent using the header
9434 specified by the icap_client_username_header option.
cccac0a2 9435DOC_END
9436
5473c134 9437NAME: icap_client_username_header
cccac0a2 9438TYPE: string
5473c134 9439IFDEF: ICAP_CLIENT
26cc52cb 9440LOC: Adaptation::Icap::TheConfig.client_username_header
5473c134 9441DEFAULT: X-Client-Username
cccac0a2 9442DOC_START
db49f682 9443 ICAP request header name to use for adaptation_send_username.
cccac0a2 9444DOC_END
9445
5473c134 9446NAME: icap_client_username_encode
cccac0a2 9447TYPE: onoff
5473c134 9448IFDEF: ICAP_CLIENT
9449COMMENT: on|off
26cc52cb 9450LOC: Adaptation::Icap::TheConfig.client_username_encode
5473c134 9451DEFAULT: off
cccac0a2 9452DOC_START
5473c134 9453 Whether to base64 encode the authenticated client username.
cccac0a2 9454DOC_END
9455
5473c134 9456NAME: icap_service
9457TYPE: icap_service_type
9458IFDEF: ICAP_CLIENT
26cc52cb 9459LOC: Adaptation::Icap::TheConfig
5473c134 9460DEFAULT: none
cccac0a2 9461DOC_START
a22e6cd3 9462 Defines a single ICAP service using the following format:
cccac0a2 9463
c25c2836 9464 icap_service id vectoring_point uri [option ...]
7d90757b 9465
c25c2836
CT
9466 id: ID
9467 an opaque identifier or name which is used to direct traffic to
9468 this specific service. Must be unique among all adaptation
9469 services in squid.conf.
a22e6cd3
AR
9470
9471 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
f3db09e2 9472 This specifies at which point of transaction processing the
9473 ICAP service should be activated. *_postcache vectoring points
9474 are not yet supported.
a22e6cd3 9475
c25c2836 9476 uri: icap://servername:port/servicepath
a22e6cd3 9477 ICAP server and service location.
1b091aec
CT
9478 icaps://servername:port/servicepath
9479 The "icap:" URI scheme is used for traditional ICAP server and
9480 service location (default port is 1344, connections are not
9481 encrypted). The "icaps:" URI scheme is for Secure ICAP
9482 services that use SSL/TLS-encrypted ICAP connections (by
9483 default, on port 11344).
a22e6cd3
AR
9484
9485 ICAP does not allow a single service to handle both REQMOD and RESPMOD
9486 transactions. Squid does not enforce that requirement. You can specify
9487 services with the same service_url and different vectoring_points. You
9488 can even specify multiple identical services as long as their
9489 service_names differ.
9490
3caa16d2
AR
9491 To activate a service, use the adaptation_access directive. To group
9492 services, use adaptation_service_chain and adaptation_service_set.
a22e6cd3
AR
9493
9494 Service options are separated by white space. ICAP services support
9495 the following name=value options:
9496
9497 bypass=on|off|1|0
9498 If set to 'on' or '1', the ICAP service is treated as
9499 optional. If the service cannot be reached or malfunctions,
9500 Squid will try to ignore any errors and process the message as
9501 if the service was not enabled. No all ICAP errors can be
9502 bypassed. If set to 0, the ICAP service is treated as
9503 essential and all ICAP errors will result in an error page
9504 returned to the HTTP client.
9505
9506 Bypass is off by default: services are treated as essential.
9507
9508 routing=on|off|1|0
9509 If set to 'on' or '1', the ICAP service is allowed to
9510 dynamically change the current message adaptation plan by
9511 returning a chain of services to be used next. The services
9512 are specified using the X-Next-Services ICAP response header
9513 value, formatted as a comma-separated list of service names.
e2851fe7
AR
9514 Each named service should be configured in squid.conf. Other
9515 services are ignored. An empty X-Next-Services value results
9516 in an empty plan which ends the current adaptation.
9517
9518 Dynamic adaptation plan may cross or cover multiple supported
9519 vectoring points in their natural processing order.
a22e6cd3
AR
9520
9521 Routing is not allowed by default: the ICAP X-Next-Services
9522 response header is ignored.
9523
e6713f4e
AJ
9524 ipv6=on|off
9525 Only has effect on split-stack systems. The default on those systems
9526 is to use IPv4-only connections. When set to 'on' this option will
9527 make Squid use IPv6-only connections to contact this ICAP service.
9528
2dba5b8e
CT
9529 on-overload=block|bypass|wait|force
9530 If the service Max-Connections limit has been reached, do
9531 one of the following for each new ICAP transaction:
9532 * block: send an HTTP error response to the client
9533 * bypass: ignore the "over-connected" ICAP service
9534 * wait: wait (in a FIFO queue) for an ICAP connection slot
9603207d 9535 * force: proceed, ignoring the Max-Connections limit
2dba5b8e
CT
9536
9537 In SMP mode with N workers, each worker assumes the service
9538 connection limit is Max-Connections/N, even though not all
9539 workers may use a given service.
9540
9541 The default value is "bypass" if service is bypassable,
9542 otherwise it is set to "wait".
9603207d 9543
2dba5b8e
CT
9544
9545 max-conn=number
9546 Use the given number as the Max-Connections limit, regardless
9547 of the Max-Connections value given by the service, if any.
9548
88df846b
CT
9549 connection-encryption=on|off
9550 Determines the ICAP service effect on the connections_encrypted
9551 ACL.
9552
9553 The default is "on" for Secure ICAP services (i.e., those
9554 with the icaps:// service URIs scheme) and "off" for plain ICAP
9555 services.
9556
9557 Does not affect ICAP connections (e.g., does not turn Secure
9558 ICAP on or off).
9559
4dd2c9d6 9560 ==== ICAPS / TLS OPTIONS ====
1b091aec
CT
9561
9562 These options are used for Secure ICAP (icaps://....) services only.
9563
4dd2c9d6 9564 tls-cert=/path/to/ssl/certificate
51e09c08
AJ
9565 A client X.509 certificate to use when connecting to
9566 this ICAP server.
1b091aec 9567
4dd2c9d6 9568 tls-key=/path/to/ssl/key
51e09c08
AJ
9569 The private key corresponding to the previous
9570 tls-cert= option.
9571
9572 If tls-key= is not specified tls-cert= is assumed to
9573 reference a PEM file containing both the certificate
9574 and private key.
1b091aec 9575
4dd2c9d6 9576 tls-cipher=... The list of valid TLS/SSL ciphers to use when connecting
1b091aec
CT
9577 to this icap server.
9578
1cc44095
AJ
9579 tls-min-version=1.N
9580 The minimum TLS protocol version to permit. To control
3f5b28fe 9581 SSLv3 use the tls-options= parameter.
1cc44095
AJ
9582 Supported Values: 1.0 (default), 1.1, 1.2
9583
4dd2c9d6 9584 tls-options=... Specify various OpenSSL library options:
1b091aec
CT
9585
9586 NO_SSLv3 Disallow the use of SSLv3
4dd2c9d6 9587
1b091aec
CT
9588 SINGLE_DH_USE
9589 Always create a new key when using
9590 temporary/ephemeral DH key exchanges
4dd2c9d6 9591
1b091aec 9592 ALL Enable various bug workarounds
4dd2c9d6
AJ
9593 suggested as "harmless" by OpenSSL
9594 Be warned that this reduces SSL/TLS
9595 strength to some attacks.
1b091aec
CT
9596
9597 See the OpenSSL SSL_CTX_set_options documentation for a
4dd2c9d6
AJ
9598 more complete list. Options relevant only to SSLv2 are
9599 not supported.
1b091aec 9600
86a84cc0
AJ
9601 tls-cafile= PEM file containing CA certificates to use when verifying
9602 the icap server certificate.
9603 Use to specify intermediate CA certificate(s) if not sent
9604 by the server. Or the full CA chain for the server when
435c72b0 9605 using the tls-default-ca=off flag.
86a84cc0 9606 May be repeated to load multiple files.
1b091aec 9607
4dd2c9d6 9608 tls-capath=... A directory containing additional CA certificates to
1b091aec 9609 use when verifying the icap server certificate.
86a84cc0 9610 Requires OpenSSL or LibreSSL.
1b091aec 9611
4dd2c9d6 9612 tls-crlfile=... A certificate revocation list file to use when
1b091aec
CT
9613 verifying the icap server certificate.
9614
4dd2c9d6 9615 tls-flags=... Specify various flags modifying the Squid TLS implementation:
1b091aec
CT
9616
9617 DONT_VERIFY_PEER
9618 Accept certificates even if they fail to
9619 verify.
1b091aec
CT
9620 DONT_VERIFY_DOMAIN
9621 Don't verify the icap server certificate
9622 matches the server name
9623
435c72b0
AJ
9624 tls-default-ca[=off]
9625 Whether to use the system Trusted CAs. Default is ON.
8b253b83 9626
4dd2c9d6 9627 tls-domain= The icap server name as advertised in it's certificate.
1b091aec
CT
9628 Used for verifying the correctness of the received icap
9629 server certificate. If not specified the icap server
9630 hostname extracted from ICAP URI will be used.
9631
a22e6cd3
AR
9632 Older icap_service format without optional named parameters is
9633 deprecated but supported for backward compatibility.
5473c134 9634
5473c134 9635Example:
c25c2836 9636icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
1b091aec 9637icap_service svcLogger reqmod_precache icaps://icap2.mydomain.net:11344/reqmod routing=on
cccac0a2 9638DOC_END
9639
5473c134 9640NAME: icap_class
9641TYPE: icap_class_type
9642IFDEF: ICAP_CLIENT
21a26d31 9643LOC: none
5473c134 9644DEFAULT: none
cccac0a2 9645DOC_START
a22e6cd3 9646 This deprecated option was documented to define an ICAP service
62c7f90e 9647 chain, even though it actually defined a set of similar, redundant
9603207d 9648 services, and the chains were not supported.
5473c134 9649
62c7f90e 9650 To define a set of redundant services, please use the
a22e6cd3
AR
9651 adaptation_service_set directive. For service chains, use
9652 adaptation_service_chain.
cccac0a2 9653DOC_END
9654
5473c134 9655NAME: icap_access
9656TYPE: icap_access_type
9657IFDEF: ICAP_CLIENT
21a26d31 9658LOC: none
cccac0a2 9659DEFAULT: none
cccac0a2 9660DOC_START
a22e6cd3 9661 This option is deprecated. Please use adaptation_access, which
62c7f90e
AR
9662 has the same ICAP functionality, but comes with better
9663 documentation, and eCAP support.
cccac0a2 9664DOC_END
9665
57afc994
AR
9666COMMENT_START
9667 eCAP OPTIONS
9668 -----------------------------------------------------------------------------
9669COMMENT_END
9670
21a26d31
AR
9671NAME: ecap_enable
9672TYPE: onoff
9673IFDEF: USE_ECAP
9674COMMENT: on|off
574b508c 9675LOC: Adaptation::Ecap::TheConfig.onoff
21a26d31
AR
9676DEFAULT: off
9677DOC_START
9678 Controls whether eCAP support is enabled.
9679DOC_END
9680
9681NAME: ecap_service
9682TYPE: ecap_service_type
9683IFDEF: USE_ECAP
574b508c 9684LOC: Adaptation::Ecap::TheConfig
21a26d31
AR
9685DEFAULT: none
9686DOC_START
9687 Defines a single eCAP service
9688
c25c2836 9689 ecap_service id vectoring_point uri [option ...]
21a26d31 9690
c25c2836
CT
9691 id: ID
9692 an opaque identifier or name which is used to direct traffic to
9693 this specific service. Must be unique among all adaptation
9694 services in squid.conf.
9695
9696 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
21a26d31
AR
9697 This specifies at which point of transaction processing the
9698 eCAP service should be activated. *_postcache vectoring points
9699 are not yet supported.
c25c2836
CT
9700
9701 uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
9702 Squid uses the eCAP service URI to match this configuration
9703 line with one of the dynamically loaded services. Each loaded
9704 eCAP service must have a unique URI. Obtain the right URI from
9705 the service provider.
9706
3caa16d2
AR
9707 To activate a service, use the adaptation_access directive. To group
9708 services, use adaptation_service_chain and adaptation_service_set.
c25c2836
CT
9709
9710 Service options are separated by white space. eCAP services support
9711 the following name=value options:
9712
9713 bypass=on|off|1|0
9714 If set to 'on' or '1', the eCAP service is treated as optional.
9715 If the service cannot be reached or malfunctions, Squid will try
9716 to ignore any errors and process the message as if the service
21a26d31 9717 was not enabled. No all eCAP errors can be bypassed.
c25c2836
CT
9718 If set to 'off' or '0', the eCAP service is treated as essential
9719 and all eCAP errors will result in an error page returned to the
21a26d31 9720 HTTP client.
c25c2836
CT
9721
9722 Bypass is off by default: services are treated as essential.
9723
9724 routing=on|off|1|0
9725 If set to 'on' or '1', the eCAP service is allowed to
9726 dynamically change the current message adaptation plan by
9727 returning a chain of services to be used next.
9728
9729 Dynamic adaptation plan may cross or cover multiple supported
9730 vectoring points in their natural processing order.
9731
9732 Routing is not allowed by default.
9733
88df846b
CT
9734 connection-encryption=on|off
9735 Determines the eCAP service effect on the connections_encrypted
9603207d 9736 ACL.
88df846b
CT
9737
9738 Defaults to "on", which does not taint the master transaction
9739 w.r.t. that ACL.
9740
9741 Does not affect eCAP API calls.
9742
c25c2836
CT
9743 Older ecap_service format without optional named parameters is
9744 deprecated but supported for backward compatibility.
9745
21a26d31
AR
9746
9747Example:
c25c2836
CT
9748ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
9749ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
21a26d31
AR
9750DOC_END
9751
57afc994
AR
9752NAME: loadable_modules
9753TYPE: wordlist
9754IFDEF: USE_LOADABLE_MODULES
9755LOC: Config.loadable_module_names
9756DEFAULT: none
9757DOC_START
9758 Instructs Squid to load the specified dynamic module(s) or activate
9759 preloaded module(s).
9760Example:
9761loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
9762DOC_END
9763
62c7f90e
AR
9764COMMENT_START
9765 MESSAGE ADAPTATION OPTIONS
9766 -----------------------------------------------------------------------------
9767COMMENT_END
9768
9769NAME: adaptation_service_set
9770TYPE: adaptation_service_set_type
9771IFDEF: USE_ADAPTATION
9772LOC: none
9773DEFAULT: none
9774DOC_START
9775
a22e6cd3
AR
9776 Configures an ordered set of similar, redundant services. This is
9777 useful when hot standby or backup adaptation servers are available.
9778
9779 adaptation_service_set set_name service_name1 service_name2 ...
9780
9781 The named services are used in the set declaration order. The first
9782 applicable adaptation service from the set is used first. The next
9783 applicable service is tried if and only if the transaction with the
9784 previous service fails and the message waiting to be adapted is still
9785 intact.
62c7f90e 9786
a22e6cd3
AR
9787 When adaptation starts, broken services are ignored as if they were
9788 not a part of the set. A broken service is a down optional service.
62c7f90e 9789
a22e6cd3
AR
9790 The services in a set must be attached to the same vectoring point
9791 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
9792
9793 If all services in a set are optional then adaptation failures are
9794 bypassable. If all services in the set are essential, then a
9795 transaction failure with one service may still be retried using
9796 another service from the set, but when all services fail, the master
9797 transaction fails as well.
9798
9799 A set may contain a mix of optional and essential services, but that
9800 is likely to lead to surprising results because broken services become
9801 ignored (see above), making previously bypassable failures fatal.
9802 Technically, it is the bypassability of the last failed service that
9803 matters.
9804
9805 See also: adaptation_access adaptation_service_chain
62c7f90e
AR
9806
9807Example:
9808adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
9809adaptation service_set svcLogger loggerLocal loggerRemote
9810DOC_END
9811
a22e6cd3
AR
9812NAME: adaptation_service_chain
9813TYPE: adaptation_service_chain_type
9814IFDEF: USE_ADAPTATION
9815LOC: none
9816DEFAULT: none
9817DOC_START
9818
9819 Configures a list of complementary services that will be applied
9820 one-by-one, forming an adaptation chain or pipeline. This is useful
9821 when Squid must perform different adaptations on the same message.
9822
9823 adaptation_service_chain chain_name service_name1 svc_name2 ...
9824
9825 The named services are used in the chain declaration order. The first
9826 applicable adaptation service from the chain is used first. The next
9827 applicable service is applied to the successful adaptation results of
9828 the previous service in the chain.
9829
9830 When adaptation starts, broken services are ignored as if they were
9831 not a part of the chain. A broken service is a down optional service.
9832
9833 Request satisfaction terminates the adaptation chain because Squid
9834 does not currently allow declaration of RESPMOD services at the
9835 "reqmod_precache" vectoring point (see icap_service or ecap_service).
9836
9837 The services in a chain must be attached to the same vectoring point
9838 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
9839
9840 A chain may contain a mix of optional and essential services. If an
9841 essential adaptation fails (or the failure cannot be bypassed for
9842 other reasons), the master transaction fails. Otherwise, the failure
9843 is bypassed as if the failed adaptation service was not in the chain.
9844
9845 See also: adaptation_access adaptation_service_set
9846
9847Example:
9848adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
9849DOC_END
9850
62c7f90e
AR
9851NAME: adaptation_access
9852TYPE: adaptation_access_type
9853IFDEF: USE_ADAPTATION
9854LOC: none
9855DEFAULT: none
638402dd 9856DEFAULT_DOC: Allow, unless rules exist in squid.conf.
62c7f90e
AR
9857DOC_START
9858 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
9859
9860 adaptation_access service_name allow|deny [!]aclname...
9861 adaptation_access set_name allow|deny [!]aclname...
9862
9863 At each supported vectoring point, the adaptation_access
9864 statements are processed in the order they appear in this
9865 configuration file. Statements pointing to the following services
9866 are ignored (i.e., skipped without checking their ACL):
9867
9868 - services serving different vectoring points
9869 - "broken-but-bypassable" services
9870 - "up" services configured to ignore such transactions
9871 (e.g., based on the ICAP Transfer-Ignore header).
9872
9873 When a set_name is used, all services in the set are checked
9874 using the same rules, to find the first applicable one. See
9875 adaptation_service_set for details.
9876
9877 If an access list is checked and there is a match, the
9878 processing stops: For an "allow" rule, the corresponding
9879 adaptation service is used for the transaction. For a "deny"
9880 rule, no adaptation service is activated.
9881
9882 It is currently not possible to apply more than one adaptation
9883 service at the same vectoring point to the same HTTP transaction.
9884
9885 See also: icap_service and ecap_service
9886
9887Example:
9888adaptation_access service_1 allow all
9889DOC_END
9890
a22e6cd3
AR
9891NAME: adaptation_service_iteration_limit
9892TYPE: int
9893IFDEF: USE_ADAPTATION
9894LOC: Adaptation::Config::service_iteration_limit
9895DEFAULT: 16
9896DOC_START
9897 Limits the number of iterations allowed when applying adaptation
9898 services to a message. If your longest adaptation set or chain
9899 may have more than 16 services, increase the limit beyond its
9900 default value of 16. If detecting infinite iteration loops sooner
9901 is critical, make the iteration limit match the actual number
9902 of services in your longest adaptation set or chain.
9903
9904 Infinite adaptation loops are most likely with routing services.
9905
9906 See also: icap_service routing=1
9907DOC_END
9908
3ff65596
AR
9909NAME: adaptation_masterx_shared_names
9910TYPE: string
9911IFDEF: USE_ADAPTATION
9912LOC: Adaptation::Config::masterx_shared_name
9913DEFAULT: none
9914DOC_START
9915 For each master transaction (i.e., the HTTP request and response
9916 sequence, including all related ICAP and eCAP exchanges), Squid
9917 maintains a table of metadata. The table entries are (name, value)
9918 pairs shared among eCAP and ICAP exchanges. The table is destroyed
9919 with the master transaction.
9920
9921 This option specifies the table entry names that Squid must accept
9922 from and forward to the adaptation transactions.
9923
9603207d 9924 An ICAP REQMOD or RESPMOD transaction may set an entry in the
9925 shared table by returning an ICAP header field with a name
6666da11
AR
9926 specified in adaptation_masterx_shared_names.
9927
9928 An eCAP REQMOD or RESPMOD transaction may set an entry in the
9929 shared table by implementing the libecap::visitEachOption() API
9930 to provide an option with a name specified in
9931 adaptation_masterx_shared_names.
5038f9d8
AR
9932
9933 Squid will store and forward the set entry to subsequent adaptation
3ff65596
AR
9934 transactions within the same master transaction scope.
9935
9936 Only one shared entry name is supported at this time.
9937
9938Example:
9939# share authentication information among ICAP services
9940adaptation_masterx_shared_names X-Subscriber-ID
9941DOC_END
9942
71be37e0 9943NAME: adaptation_meta
d7f4a0b7 9944TYPE: note
71be37e0
CT
9945IFDEF: USE_ADAPTATION
9946LOC: Adaptation::Config::metaHeaders
9947DEFAULT: none
9948DOC_START
9949 This option allows Squid administrator to add custom ICAP request
9950 headers or eCAP options to Squid ICAP requests or eCAP transactions.
9951 Use it to pass custom authentication tokens and other
9952 transaction-state related meta information to an ICAP/eCAP service.
9603207d 9953
71be37e0
CT
9954 The addition of a meta header is ACL-driven:
9955 adaptation_meta name value [!]aclname ...
9603207d 9956
71be37e0
CT
9957 Processing for a given header name stops after the first ACL list match.
9958 Thus, it is impossible to add two headers with the same name. If no ACL
9603207d 9959 lists match for a given header name, no such header is added. For
71be37e0 9960 example:
9603207d 9961
71be37e0
CT
9962 # do not debug transactions except for those that need debugging
9963 adaptation_meta X-Debug 1 needs_debugging
9603207d 9964
71be37e0
CT
9965 # log all transactions except for those that must remain secret
9966 adaptation_meta X-Log 1 !keep_secret
9603207d 9967
71be37e0
CT
9968 # mark transactions from users in the "G 1" group
9969 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
9603207d 9970
71be37e0
CT
9971 The "value" parameter may be a regular squid.conf token or a "double
9972 quoted string". Within the quoted string, use backslash (\) to escape
9973 any character, which is currently only useful for escaping backslashes
9974 and double quotes. For example,
9975 "this string has one backslash (\\) and two \"quotes\""
d7f4a0b7
CT
9976
9977 Used adaptation_meta header values may be logged via %note
9978 logformat code. If multiple adaptation_meta headers with the same name
9979 are used during master transaction lifetime, the header values are
9980 logged in the order they were used and duplicate values are ignored
9981 (only the first repeated value will be logged).
71be37e0
CT
9982DOC_END
9983
3ff65596
AR
9984NAME: icap_retry
9985TYPE: acl_access
9986IFDEF: ICAP_CLIENT
9987LOC: Adaptation::Icap::TheConfig.repeat
3ff65596
AR
9988DEFAULT_IF_NONE: deny all
9989DOC_START
9990 This ACL determines which retriable ICAP transactions are
9991 retried. Transactions that received a complete ICAP response
9992 and did not have to consume or produce HTTP bodies to receive
9993 that response are usually retriable.
9994
9995 icap_retry allow|deny [!]aclname ...
9996
9997 Squid automatically retries some ICAP I/O timeouts and errors
9998 due to persistent connection race conditions.
9999
10000 See also: icap_retry_limit
10001DOC_END
10002
10003NAME: icap_retry_limit
10004TYPE: int
10005IFDEF: ICAP_CLIENT
10006LOC: Adaptation::Icap::TheConfig.repeat_limit
10007DEFAULT: 0
638402dd 10008DEFAULT_DOC: No retries are allowed.
3ff65596 10009DOC_START
638402dd 10010 Limits the number of retries allowed.
3ff65596
AR
10011
10012 Communication errors due to persistent connection race
10013 conditions are unavoidable, automatically retried, and do not
10014 count against this limit.
10015
10016 See also: icap_retry
10017DOC_END
10018
10019
5473c134 10020COMMENT_START
10021 DNS OPTIONS
10022 -----------------------------------------------------------------------------
10023COMMENT_END
10024
10025NAME: check_hostnames
cccac0a2 10026TYPE: onoff
cccac0a2 10027DEFAULT: off
5473c134 10028LOC: Config.onoff.check_hostnames
cccac0a2 10029DOC_START
5473c134 10030 For security and stability reasons Squid can check
10031 hostnames for Internet standard RFC compliance. If you want
10032 Squid to perform these checks turn this directive on.
cccac0a2 10033DOC_END
10034
5473c134 10035NAME: allow_underscore
cccac0a2 10036TYPE: onoff
cccac0a2 10037DEFAULT: on
5473c134 10038LOC: Config.onoff.allow_underscore
cccac0a2 10039DOC_START
5473c134 10040 Underscore characters is not strictly allowed in Internet hostnames
10041 but nevertheless used by many sites. Set this to off if you want
10042 Squid to be strict about the standard.
10043 This check is performed only when check_hostnames is set to on.
cccac0a2 10044DOC_END
10045
5473c134 10046NAME: dns_retransmit_interval
fd0f51c4 10047TYPE: time_msec
5473c134 10048DEFAULT: 5 seconds
10049LOC: Config.Timeout.idns_retransmit
cccac0a2 10050DOC_START
5473c134 10051 Initial retransmit interval for DNS queries. The interval is
10052 doubled each time all configured DNS servers have been tried.
cccac0a2 10053DOC_END
10054
5473c134 10055NAME: dns_timeout
fd0f51c4 10056TYPE: time_msec
a541c34e 10057DEFAULT: 30 seconds
5473c134 10058LOC: Config.Timeout.idns_query
cccac0a2 10059DOC_START
5473c134 10060 DNS Query timeout. If no response is received to a DNS query
10061 within this time all DNS servers for the queried domain
10062 are assumed to be unavailable.
cccac0a2 10063DOC_END
10064
e210930b
AJ
10065NAME: dns_packet_max
10066TYPE: b_ssize_t
638402dd 10067DEFAULT_DOC: EDNS disabled
e210930b
AJ
10068DEFAULT: none
10069LOC: Config.dns.packet_max
e210930b
AJ
10070DOC_START
10071 Maximum number of bytes packet size to advertise via EDNS.
10072 Set to "none" to disable EDNS large packet support.
9603207d 10073
e210930b
AJ
10074 For legacy reasons DNS UDP replies will default to 512 bytes which
10075 is too small for many responses. EDNS provides a means for Squid to
10076 negotiate receiving larger responses back immediately without having
10077 to failover with repeat requests. Responses larger than this limit
10078 will retain the old behaviour of failover to TCP DNS.
9603207d 10079
e210930b
AJ
10080 Squid has no real fixed limit internally, but allowing packet sizes
10081 over 1500 bytes requires network jumbogram support and is usually not
10082 necessary.
9603207d 10083
e210930b
AJ
10084 WARNING: The RFC also indicates that some older resolvers will reply
10085 with failure of the whole request if the extension is added. Some
10086 resolvers have already been identified which will reply with mangled
10087 EDNS response on occasion. Usually in response to many-KB jumbogram
10088 sizes being advertised by Squid.
10089 Squid will currently treat these both as an unable-to-resolve domain
10090 even if it would be resolvable without EDNS.
10091DOC_END
10092
5473c134 10093NAME: dns_defnames
10094COMMENT: on|off
cccac0a2 10095TYPE: onoff
cccac0a2 10096DEFAULT: off
638402dd 10097DEFAULT_DOC: Search for single-label domain names is disabled.
5473c134 10098LOC: Config.onoff.res_defnames
cccac0a2 10099DOC_START
5473c134 10100 Normally the RES_DEFNAMES resolver option is disabled
10101 (see res_init(3)). This prevents caches in a hierarchy
10102 from interpreting single-component hostnames locally. To allow
10103 Squid to handle single-component names, enable this option.
cccac0a2 10104DOC_END
10105
bce61b00
AJ
10106NAME: dns_multicast_local
10107COMMENT: on|off
10108TYPE: onoff
10109DEFAULT: off
10110DEFAULT_DOC: Search for .local and .arpa names is disabled.
10111LOC: Config.onoff.dns_mdns
10112DOC_START
10113 When set to on, Squid sends multicast DNS lookups on the local
10114 network for domains ending in .local and .arpa.
10115 This enables local servers and devices to be contacted in an
10116 ad-hoc or zero-configuration network environment.
10117DOC_END
10118
5473c134 10119NAME: dns_nameservers
5a1098fb 10120TYPE: SBufList
5473c134 10121DEFAULT: none
638402dd 10122DEFAULT_DOC: Use operating system definitions
5a1098fb 10123LOC: Config.dns.nameservers
cccac0a2 10124DOC_START
5473c134 10125 Use this if you want to specify a list of DNS name servers
10126 (IP addresses) to use instead of those given in your
10127 /etc/resolv.conf file.
638402dd 10128
5473c134 10129 On Windows platforms, if no value is specified here or in
10130 the /etc/resolv.conf file, the list of DNS name servers are
10131 taken from the Windows registry, both static and dynamic DHCP
10132 configurations are supported.
cccac0a2 10133
5473c134 10134 Example: dns_nameservers 10.0.0.1 192.172.0.4
cccac0a2 10135DOC_END
10136
5473c134 10137NAME: hosts_file
cccac0a2 10138TYPE: string
5473c134 10139DEFAULT: @DEFAULT_HOSTS@
10140LOC: Config.etcHostsPath
cccac0a2 10141DOC_START
5473c134 10142 Location of the host-local IP name-address associations
10143 database. Most Operating Systems have such a file on different
10144 default locations:
10145 - Un*X & Linux: /etc/hosts
10146 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
10147 (%SystemRoot% value install default is c:\winnt)
10148 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
10149 (%SystemRoot% value install default is c:\windows)
10150 - Windows 9x/Me: %windir%\hosts
10151 (%windir% value is usually c:\windows)
10152 - Cygwin: /etc/hosts
cccac0a2 10153
5473c134 10154 The file contains newline-separated definitions, in the
10155 form ip_address_in_dotted_form name [name ...] names are
10156 whitespace-separated. Lines beginning with an hash (#)
10157 character are comments.
cccac0a2 10158
5473c134 10159 The file is checked at startup and upon configuration.
10160 If set to 'none', it won't be checked.
10161 If append_domain is used, that domain will be added to
10162 domain-local (i.e. not containing any dot character) host
10163 definitions.
cccac0a2 10164DOC_END
10165
5473c134 10166NAME: append_domain
10167TYPE: string
10168LOC: Config.appendDomain
10169DEFAULT: none
638402dd 10170DEFAULT_DOC: Use operating system definitions
6a2f3fcf 10171DOC_START
5473c134 10172 Appends local domain name to hostnames without any dots in
10173 them. append_domain must begin with a period.
10174
10175 Be warned there are now Internet names with no dots in
10176 them using only top-domain names, so setting this may
10177 cause some Internet sites to become unavailable.
10178
10179Example:
10180 append_domain .yourdomain.com
6a2f3fcf 10181DOC_END
10182
5473c134 10183NAME: ignore_unknown_nameservers
10184TYPE: onoff
10185LOC: Config.onoff.ignore_unknown_nameservers
df6fd596 10186DEFAULT: on
10187DOC_START
5473c134 10188 By default Squid checks that DNS responses are received
10189 from the same IP addresses they are sent to. If they
10190 don't match, Squid ignores the response and writes a warning
10191 message to cache.log. You can allow responses from unknown
10192 nameservers by setting this option to 'off'.
df6fd596 10193DOC_END
10194
6bc15a4f 10195NAME: ipcache_size
10196COMMENT: (number of entries)
10197TYPE: int
10198DEFAULT: 1024
10199LOC: Config.ipcache.size
638402dd
AJ
10200DOC_START
10201 Maximum number of DNS IP cache entries.
10202DOC_END
6bc15a4f 10203
10204NAME: ipcache_low
10205COMMENT: (percent)
10206TYPE: int
10207DEFAULT: 90
10208LOC: Config.ipcache.low
10209DOC_NONE
10210
10211NAME: ipcache_high
10212COMMENT: (percent)
10213TYPE: int
10214DEFAULT: 95
10215LOC: Config.ipcache.high
10216DOC_START
10217 The size, low-, and high-water marks for the IP cache.
10218DOC_END
10219
10220NAME: fqdncache_size
10221COMMENT: (number of entries)
10222TYPE: int
10223DEFAULT: 1024
10224LOC: Config.fqdncache.size
10225DOC_START
10226 Maximum number of FQDN cache entries.
10227DOC_END
10228
a58ff010 10229COMMENT_START
5473c134 10230 MISCELLANEOUS
a58ff010 10231 -----------------------------------------------------------------------------
10232COMMENT_END
10233
2eceb328
CT
10234NAME: configuration_includes_quoted_values
10235COMMENT: on|off
bde7a8ce
CT
10236TYPE: configuration_includes_quoted_values
10237DEFAULT: off
2eceb328
CT
10238LOC: ConfigParser::RecognizeQuotedValues
10239DOC_START
10240 If set, Squid will recognize each "quoted string" after a configuration
10241 directive as a single parameter. The quotes are stripped before the
10242 parameter value is interpreted or used.
10243 See "Values with spaces, quotes, and other special characters"
10244 section for more details.
10245DOC_END
10246
5473c134 10247NAME: memory_pools
a58ff010 10248COMMENT: on|off
5473c134 10249TYPE: onoff
10250DEFAULT: on
10251LOC: Config.onoff.mem_pools
a58ff010 10252DOC_START
5473c134 10253 If set, Squid will keep pools of allocated (but unused) memory
10254 available for future use. If memory is a premium on your
10255 system and you believe your malloc library outperforms Squid
10256 routines, disable this.
a58ff010 10257DOC_END
10258
5473c134 10259NAME: memory_pools_limit
10260COMMENT: (bytes)
70be1349 10261TYPE: b_int64_t
5473c134 10262DEFAULT: 5 MB
10263LOC: Config.MemPools.limit
ec1245f8 10264DOC_START
5473c134 10265 Used only with memory_pools on:
10266 memory_pools_limit 50 MB
ec1245f8 10267
5473c134 10268 If set to a non-zero value, Squid will keep at most the specified
10269 limit of allocated (but unused) memory in memory pools. All free()
10270 requests that exceed this limit will be handled by your malloc
10271 library. Squid does not pre-allocate any memory, just safe-keeps
10272 objects that otherwise would be free()d. Thus, it is safe to set
10273 memory_pools_limit to a reasonably high value even if your
10274 configuration will use less memory.
ec1245f8 10275
89646bd7 10276 If set to none, Squid will keep all memory it can. That is, there
5473c134 10277 will be no limit on the total amount of memory used for safe-keeping.
ec1245f8 10278
5473c134 10279 To disable memory allocation optimization, do not set
70be1349 10280 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
5473c134 10281
10282 An overhead for maintaining memory pools is not taken into account
10283 when the limit is checked. This overhead is close to four bytes per
10284 object kept. However, pools may actually _save_ memory because of
10285 reduced memory thrashing in your malloc library.
ec1245f8 10286DOC_END
10287
5473c134 10288NAME: forwarded_for
67c06f0d
AJ
10289COMMENT: on|off|transparent|truncate|delete
10290TYPE: string
5473c134 10291DEFAULT: on
10292LOC: opt_forwarded_for
5f8252d2 10293DOC_START
67c06f0d
AJ
10294 If set to "on", Squid will append your client's IP address
10295 in the HTTP requests it forwards. By default it looks like:
5f8252d2 10296
5473c134 10297 X-Forwarded-For: 192.1.2.3
10298
67c06f0d 10299 If set to "off", it will appear as
5473c134 10300
10301 X-Forwarded-For: unknown
67c06f0d
AJ
10302
10303 If set to "transparent", Squid will not alter the
10304 X-Forwarded-For header in any way.
10305
10306 If set to "delete", Squid will delete the entire
10307 X-Forwarded-For header.
10308
10309 If set to "truncate", Squid will remove all existing
dd68402f 10310 X-Forwarded-For entries, and place the client IP as the sole entry.
5f8252d2 10311DOC_END
10312
5473c134 10313NAME: cachemgr_passwd
10314TYPE: cachemgrpasswd
10315DEFAULT: none
638402dd 10316DEFAULT_DOC: No password. Actions which require password are denied.
5473c134 10317LOC: Config.passwd_list
5f8252d2 10318DOC_START
5473c134 10319 Specify passwords for cachemgr operations.
5f8252d2 10320
5473c134 10321 Usage: cachemgr_passwd password action action ...
10322
10323 Some valid actions are (see cache manager menu for a full list):
10324 5min
10325 60min
10326 asndb
10327 authenticator
10328 cbdata
10329 client_list
10330 comm_incoming
10331 config *
10332 counters
10333 delay
10334 digest_stats
10335 dns
10336 events
10337 filedescriptors
10338 fqdncache
10339 histograms
10340 http_headers
10341 info
10342 io
10343 ipcache
10344 mem
10345 menu
10346 netdb
10347 non_peers
10348 objects
10349 offline_toggle *
10350 pconn
10351 peer_select
b360c477 10352 reconfigure *
5473c134 10353 redirector
10354 refresh
10355 server_list
10356 shutdown *
10357 store_digest
10358 storedir
10359 utilization
10360 via_headers
10361 vm_objects
10362
10363 * Indicates actions which will not be performed without a
10364 valid password, others can be performed if not listed here.
10365
10366 To disable an action, set the password to "disable".
10367 To allow performing an action without a password, set the
10368 password to "none".
10369
10370 Use the keyword "all" to set the same password for all actions.
10371
10372Example:
10373 cachemgr_passwd secret shutdown
10374 cachemgr_passwd lesssssssecret info stats/objects
10375 cachemgr_passwd disable all
5f8252d2 10376DOC_END
10377
5473c134 10378NAME: client_db
a58ff010 10379COMMENT: on|off
5473c134 10380TYPE: onoff
10381DEFAULT: on
10382LOC: Config.onoff.client_db
a58ff010 10383DOC_START
5473c134 10384 If you want to disable collecting per-client statistics,
10385 turn off client_db here.
a58ff010 10386DOC_END
10387
5473c134 10388NAME: refresh_all_ims
10389COMMENT: on|off
10390TYPE: onoff
10391DEFAULT: off
10392LOC: Config.onoff.refresh_all_ims
a58ff010 10393DOC_START
5473c134 10394 When you enable this option, squid will always check
10395 the origin server for an update when a client sends an
10396 If-Modified-Since request. Many browsers use IMS
10397 requests when the user requests a reload, and this
10398 ensures those clients receive the latest version.
a58ff010 10399
5473c134 10400 By default (off), squid may return a Not Modified response
10401 based on the age of the cached version.
78e8cfc4 10402DOC_END
10403
5473c134 10404NAME: reload_into_ims
626096be 10405IFDEF: USE_HTTP_VIOLATIONS
12b91c99 10406COMMENT: on|off
5473c134 10407TYPE: onoff
10408DEFAULT: off
10409LOC: Config.onoff.reload_into_ims
12b91c99 10410DOC_START
5473c134 10411 When you enable this option, client no-cache or ``reload''
10412 requests will be changed to If-Modified-Since requests.
10413 Doing this VIOLATES the HTTP standard. Enabling this
10414 feature could make you liable for problems which it
10415 causes.
10416
10417 see also refresh_pattern for a more selective approach.
12b91c99 10418DOC_END
10419
31ef19cd 10420NAME: connect_retries
5473c134 10421TYPE: int
31ef19cd
AJ
10422LOC: Config.connect_retries
10423DEFAULT: 0
638402dd 10424DEFAULT_DOC: Do not retry failed connections.
a58ff010 10425DOC_START
3eebd267
EB
10426 Limits the number of reopening attempts when establishing a single
10427 TCP connection. All these attempts must still complete before the
10428 applicable connection opening timeout expires.
10429
10430 By default and when connect_retries is set to zero, Squid does not
10431 retry failed connection opening attempts.
31ef19cd 10432
3eebd267
EB
10433 The (not recommended) maximum is 10 tries. An attempt to configure a
10434 higher value results in the value of 10 being used (with a warning).
5473c134 10435
3eebd267
EB
10436 Squid may open connections to retry various high-level forwarding
10437 failures. For an outside observer, that activity may look like a
10438 low-level connection reopening attempt, but those high-level retries
10439 are governed by forward_max_tries instead.
5473c134 10440
3eebd267
EB
10441 See also: connect_timeout, forward_timeout, icap_connect_timeout,
10442 ident_timeout, and forward_max_tries.
a58ff010 10443DOC_END
10444
5473c134 10445NAME: retry_on_error
a58ff010 10446TYPE: onoff
5473c134 10447LOC: Config.retry.onerror
a58ff010 10448DEFAULT: off
10449DOC_START
aea8548b
AJ
10450 If set to ON Squid will automatically retry requests when
10451 receiving an error response with status 403 (Forbidden),
10452 500 (Internal Error), 501 or 503 (Service not available).
10453 Status 502 and 504 (Gateway errors) are always retried.
9603207d 10454
aea8548b
AJ
10455 This is mainly useful if you are in a complex cache hierarchy to
10456 work around access control errors.
9603207d 10457
aea8548b
AJ
10458 NOTE: This retry will attempt to find another working destination.
10459 Which is different from the server which just failed.
5f8252d2 10460DOC_END
10461
5473c134 10462NAME: as_whois_server
5f8252d2 10463TYPE: string
5473c134 10464LOC: Config.as_whois_server
10465DEFAULT: whois.ra.net
5f8252d2 10466DOC_START
5473c134 10467 WHOIS server to query for AS numbers. NOTE: AS numbers are
10468 queried only when Squid starts up, not for every request.
5f8252d2 10469DOC_END
10470
5473c134 10471NAME: offline_mode
5f8252d2 10472TYPE: onoff
5473c134 10473LOC: Config.onoff.offline
5f8252d2 10474DEFAULT: off
10475DOC_START
5473c134 10476 Enable this option and Squid will never try to validate cached
10477 objects.
a58ff010 10478DOC_END
10479
5473c134 10480NAME: uri_whitespace
10481TYPE: uri_whitespace
10482LOC: Config.uri_whitespace
10483DEFAULT: strip
a58ff010 10484DOC_START
5473c134 10485 What to do with requests that have whitespace characters in the
10486 URI. Options:
a58ff010 10487
5473c134 10488 strip: The whitespace characters are stripped out of the URL.
82806837
AJ
10489 This is the behavior recommended by RFC2396 and RFC3986
10490 for tolerant handling of generic URI.
10491 NOTE: This is one difference between generic URI and HTTP URLs.
10492
5473c134 10493 deny: The request is denied. The user receives an "Invalid
10494 Request" message.
82806837
AJ
10495 This is the behaviour recommended by RFC2616 for safe
10496 handling of HTTP request URL.
10497
5473c134 10498 allow: The request is allowed and the URI is not changed. The
10499 whitespace characters remain in the URI. Note the
10500 whitespace is passed to redirector processes if they
10501 are in use.
82806837
AJ
10502 Note this may be considered a violation of RFC2616
10503 request parsing where whitespace is prohibited in the
10504 URL field.
10505
5473c134 10506 encode: The request is allowed and the whitespace characters are
82806837
AJ
10507 encoded according to RFC1738.
10508
5473c134 10509 chop: The request is allowed and the URI is chopped at the
82806837
AJ
10510 first whitespace.
10511
10512
10513 NOTE the current Squid implementation of encode and chop violates
10514 RFC2616 by not using a 301 redirect after altering the URL.
5473c134 10515DOC_END
a58ff010 10516
5473c134 10517NAME: chroot
10518TYPE: string
10519LOC: Config.chroot_dir
a58ff010 10520DEFAULT: none
10521DOC_START
9f37c18a 10522 Specifies a directory where Squid should do a chroot() while
2d89f399
HN
10523 initializing. This also causes Squid to fully drop root
10524 privileges after initializing. This means, for example, if you
10525 use a HTTP port less than 1024 and try to reconfigure, you may
10526 get an error saying that Squid can not open the port.
5473c134 10527DOC_END
a58ff010 10528
5473c134 10529NAME: pipeline_prefetch
079a8480
AJ
10530TYPE: pipelinePrefetch
10531LOC: Config.pipeline_max_prefetch
10532DEFAULT: 0
10533DEFAULT_DOC: Do not pre-parse pipelined requests.
a58ff010 10534DOC_START
079a8480
AJ
10535 HTTP clients may send a pipeline of 1+N requests to Squid using a
10536 single connection, without waiting for Squid to respond to the first
10537 of those requests. This option limits the number of concurrent
10538 requests Squid will try to handle in parallel. If set to N, Squid
10539 will try to receive and process up to 1+N requests on the same
10540 connection concurrently.
a58ff010 10541
079a8480 10542 Defaults to 0 (off) for bandwidth management and access logging
5473c134 10543 reasons.
a0e23afd 10544
079a8480
AJ
10545 NOTE: pipelining requires persistent connections to clients.
10546
a0e23afd 10547 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
5473c134 10548DOC_END
a58ff010 10549
5473c134 10550NAME: high_response_time_warning
10551TYPE: int
10552COMMENT: (msec)
10553LOC: Config.warnings.high_rptm
10554DEFAULT: 0
638402dd 10555DEFAULT_DOC: disabled.
5473c134 10556DOC_START
10557 If the one-minute median response time exceeds this value,
10558 Squid prints a WARNING with debug level 0 to get the
10559 administrators attention. The value is in milliseconds.
a58ff010 10560DOC_END
10561
5473c134 10562NAME: high_page_fault_warning
10563TYPE: int
10564LOC: Config.warnings.high_pf
10565DEFAULT: 0
638402dd 10566DEFAULT_DOC: disabled.
cc9f92d4 10567DOC_START
5473c134 10568 If the one-minute average page fault rate exceeds this
10569 value, Squid prints a WARNING with debug level 0 to get
10570 the administrators attention. The value is in page faults
10571 per second.
10572DOC_END
cc9f92d4 10573
5473c134 10574NAME: high_memory_warning
10575TYPE: b_size_t
10576LOC: Config.warnings.high_memory
f2228f3b 10577IFDEF: HAVE_MSTATS&&HAVE_GNUMALLOC_H
904971da 10578DEFAULT: 0 KB
638402dd 10579DEFAULT_DOC: disabled.
5473c134 10580DOC_START
4bf2a476
FC
10581 If the memory usage (as determined by gnumalloc, if available and used)
10582 exceeds this amount, Squid prints a WARNING with debug level 0 to get
5473c134 10583 the administrators attention.
10584DOC_END
4bf2a476 10585# TODO: link high_memory_warning to mempools?
cc9f92d4 10586
5473c134 10587NAME: sleep_after_fork
10588COMMENT: (microseconds)
10589TYPE: int
10590LOC: Config.sleep_after_fork
10591DEFAULT: 0
10592DOC_START
10593 When this is set to a non-zero value, the main Squid process
10594 sleeps the specified number of microseconds after a fork()
10595 system call. This sleep may help the situation where your
10596 system reports fork() failures due to lack of (virtual)
10597 memory. Note, however, if you have a lot of child
10598 processes, these sleep delays will add up and your
10599 Squid will not service requests for some amount of time
10600 until all the child processes have been started.
10601 On Windows value less then 1000 (1 milliseconds) are
10602 rounded to 1000.
cc9f92d4 10603DOC_END
10604
b6696974 10605NAME: windows_ipaddrchangemonitor
7aa9bb3e 10606IFDEF: _SQUID_WINDOWS_
b6696974
GS
10607COMMENT: on|off
10608TYPE: onoff
10609DEFAULT: on
10610LOC: Config.onoff.WIN32_IpAddrChangeMonitor
10611DOC_START
9603207d 10612 On Windows Squid by default will monitor IP address changes and will
b6696974
GS
10613 reconfigure itself after any detected event. This is very useful for
10614 proxies connected to internet with dial-up interfaces.
10615 In some cases (a Proxy server acting as VPN gateway is one) it could be
10616 desiderable to disable this behaviour setting this to 'off'.
10617 Note: after changing this, Squid service must be restarted.
10618DOC_END
10619
a98c2da5
AJ
10620NAME: eui_lookup
10621TYPE: onoff
10622IFDEF: USE_SQUID_EUI
10623DEFAULT: on
10624LOC: Eui::TheConfig.euiLookup
10625DOC_START
10626 Whether to lookup the EUI or MAC address of a connected client.
10627DOC_END
10628
f3f0f563
AJ
10629NAME: max_filedescriptors max_filedesc
10630TYPE: int
10631DEFAULT: 0
cfab2c11 10632DEFAULT_DOC: Use operating system soft limit set by ulimit.
f3f0f563
AJ
10633LOC: Config.max_filedescriptors
10634DOC_START
cfab2c11
D
10635 Set the maximum number of filedescriptors, either below the
10636 operating system default or up to the hard limit.
f3f0f563 10637
cfab2c11
D
10638 Remove from squid.conf to inherit the current ulimit soft
10639 limit setting.
f3f0f563
AJ
10640
10641 Note: Changing this requires a restart of Squid. Also
638402dd 10642 not all I/O types supports large values (eg on Windows).
f3f0f563
AJ
10643DOC_END
10644
ec69bdb2
CT
10645NAME: force_request_body_continuation
10646TYPE: acl_access
10647LOC: Config.accessList.forceRequestBodyContinuation
10648DEFAULT: none
10649DEFAULT_DOC: Deny, unless rules exist in squid.conf.
10650DOC_START
10651 This option controls how Squid handles data upload requests from HTTP
10652 and FTP agents that require a "Please Continue" control message response
10653 to actually send the request body to Squid. It is mostly useful in
10654 adaptation environments.
9603207d 10655
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CT
10656 When Squid receives an HTTP request with an "Expect: 100-continue"
10657 header or an FTP upload command (e.g., STOR), Squid normally sends the
10658 request headers or FTP command information to an adaptation service (or
10659 peer) and waits for a response. Most adaptation services (and some
10660 broken peers) may not respond to Squid at that stage because they may
10661 decide to wait for the HTTP request body or FTP data transfer. However,
10662 that request body or data transfer may never come because Squid has not
10663 responded with the HTTP 100 or FTP 150 (Please Continue) control message
10664 to the request sender yet!
9603207d 10665
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CT
10666 An allow match tells Squid to respond with the HTTP 100 or FTP 150
10667 (Please Continue) control message on its own, before forwarding the
10668 request to an adaptation service or peer. Such a response usually forces
10669 the request sender to proceed with sending the body. A deny match tells
10670 Squid to delay that control response until the origin server confirms
10671 that the request body is needed. Delaying is the default behavior.
10672DOC_END
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10673
10674NAME: http_upgrade_request_protocols
10675TYPE: http_upgrade_request_protocols
10676LOC: Config.http_upgrade_request_protocols
10677DEFAULT: none
10678DEFAULT_DOC: Upgrade header dropped, effectively blocking an upgrade attempt.
10679DOC_START
10680 Controls client-initiated and server-confirmed switching from HTTP to
10681 another protocol (or to several protocols) using HTTP Upgrade mechanism
10682 defined in RFC 7230 Section 6.7. Squid itself does not understand the
10683 protocols being upgraded to and participates in the upgraded
10684 communication only as a dumb TCP proxy. Admins should not allow
10685 upgrading to protocols that require a more meaningful proxy
10686 participation.
10687
10688 Usage: http_upgrade_request_protocols <protocol> allow|deny [!]acl ...
10689
10690 The required "protocol" parameter is either an all-caps word OTHER or an
10691 explicit protocol name (e.g. "WebSocket") optionally followed by a slash
10692 and a version token (e.g. "HTTP/3"). Explicit protocol names and
10693 versions are case sensitive.
10694
10695 When an HTTP client sends an Upgrade request header, Squid iterates over
10696 the client-offered protocols and, for each protocol P (with an optional
10697 version V), evaluates the first non-empty set of
10698 http_upgrade_request_protocols rules (if any) from the following list:
10699
10700 * All rules with an explicit protocol name equal to P.
10701 * All rules that use OTHER instead of a protocol name.
10702
10703 In other words, rules using OTHER are considered for protocol P if and
10704 only if there are no rules mentioning P by name.
10705
10706 If both of the above sets are empty, then Squid removes protocol P from
10707 the Upgrade offer.
10708
10709 If the client sent a versioned protocol offer P/X, then explicit rules
10710 referring to the same-name but different-version protocol P/Y are
10711 declared inapplicable. Inapplicable rules are not evaluated (i.e. are
10712 ignored). However, inapplicable rules still belong to the first set of
10713 rules for P.
10714
10715 Within the applicable rule subset, individual rules are evaluated in
10716 their configuration order. If all ACLs of an applicable "allow" rule
10717 match, then the protocol offered by the client is forwarded to the next
10718 hop as is. If all ACLs of an applicable "deny" rule match, then the
10719 offer is dropped. If no applicable rules have matching ACLs, then the
10720 offer is also dropped. The first matching rule also ends rules
10721 evaluation for the offered protocol.
10722
10723 If all client-offered protocols are removed, then Squid forwards the
10724 client request without the Upgrade header. Squid never sends an empty
10725 Upgrade request header.
10726
10727 An Upgrade request header with a value violating HTTP syntax is dropped
10728 and ignored without an attempt to use extractable individual protocol
10729 offers.
10730
10731 Upon receiving an HTTP 101 (Switching Protocols) control message, Squid
10732 checks that the server listed at least one protocol name and sent a
10733 Connection:upgrade response header. Squid does not understand individual
10734 protocol naming and versioning concepts enough to implement stricter
10735 checks, but an admin can restrict HTTP 101 (Switching Protocols)
10736 responses further using http_reply_access. Responses denied by
10737 http_reply_access rules and responses flagged by the internal Upgrade
10738 checks result in HTTP 502 (Bad Gateway) ERR_INVALID_RESP errors and
10739 Squid-to-server connection closures.
10740
10741 If Squid sends an Upgrade request header, and the next hop (e.g., the
10742 origin server) responds with an acceptable HTTP 101 (Switching
10743 Protocols), then Squid forwards that message to the client and becomes
10744 a TCP tunnel.
10745
10746 The presence of an Upgrade request header alone does not preclude cache
10747 lookups. In other words, an Upgrade request might be satisfied from the
10748 cache, using regular HTTP caching rules.
10749
10750 This clause only supports fast acl types.
10751 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
10752
10753 Each of the following groups of configuration lines represents a
10754 separate configuration example:
10755
10756 # never upgrade to protocol Foo; all others are OK
10757 http_upgrade_request_protocols Foo deny all
10758 http_upgrade_request_protocols OTHER allow all
10759
10760 # only allow upgrades to protocol Bar (except for its first version)
10761 http_upgrade_request_protocols Bar/1 deny all
10762 http_upgrade_request_protocols Bar allow all
10763 http_upgrade_request_protocols OTHER deny all # this rule is optional
10764
10765 # only allow upgrades to protocol Baz, and only if Baz is the only offer
10766 acl UpgradeHeaderHasMultipleOffers ...
10767 http_upgrade_request_protocols Baz deny UpgradeHeaderHasMultipleOffers
10768 http_upgrade_request_protocols Baz allow all
10769DOC_END
ec69bdb2 10770
afc753f3
EB
10771NAME: server_pconn_for_nonretriable
10772TYPE: acl_access
10773DEFAULT: none
10774DEFAULT_DOC: Open new connections for forwarding requests Squid cannot retry safely.
10775LOC: Config.accessList.serverPconnForNonretriable
10776DOC_START
10777 This option provides fine-grained control over persistent connection
10778 reuse when forwarding HTTP requests that Squid cannot retry. It is useful
10779 in environments where opening new connections is very expensive
10780 (e.g., all connections are secured with TLS with complex client and server
10781 certificate validation) and race conditions associated with persistent
10782 connections are very rare and/or only cause minor problems.
10783
10784 HTTP prohibits retrying unsafe and non-idempotent requests (e.g., POST).
10785 Squid limitations also prohibit retrying all requests with bodies (e.g., PUT).
10786 By default, when forwarding such "risky" requests, Squid opens a new
10787 connection to the server or cache_peer, even if there is an idle persistent
10788 connection available. When Squid is configured to risk sending a non-retriable
10789 request on a previously used persistent connection, and the server closes
10790 the connection before seeing that risky request, the user gets an error response
10791 from Squid. In most cases, that error response will be HTTP 502 (Bad Gateway)
10792 with ERR_ZERO_SIZE_OBJECT or ERR_WRITE_ERROR (peer connection reset) error detail.
10793
10794 If an allow rule matches, Squid reuses an available idle persistent connection
10795 (if any) for the request that Squid cannot retry. If a deny rule matches, then
10796 Squid opens a new connection for the request that Squid cannot retry.
10797
10798 This option does not affect requests that Squid can retry. They will reuse idle
10799 persistent connections (if any).
10800
10801 This clause only supports fast acl types.
10802 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
10803
10804 Example:
10805 acl SpeedIsWorthTheRisk method POST
10806 server_pconn_for_nonretriable allow SpeedIsWorthTheRisk
10807DOC_END
10808
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10809NAME: happy_eyeballs_connect_timeout
10810COMMENT: (msec)
10811TYPE: int
10812DEFAULT: 250
10813LOC: Config.happyEyeballs.connect_timeout
10814DOC_START
10815 This Happy Eyeballs (RFC 8305) tuning directive specifies the minimum
10816 delay between opening a primary to-server connection and opening a
10817 spare to-server connection for the same master transaction. This delay
10818 is similar to the Connection Attempt Delay in RFC 8305, but it is only
10819 applied to the first spare connection attempt. Subsequent spare
10820 connection attempts use happy_eyeballs_connect_gap, and primary
10821 connection attempts are not artificially delayed at all.
10822
10823 Terminology: The "primary" and "spare" designations are determined by
10824 the order of DNS answers received by Squid: If Squid DNS AAAA query
10825 was answered first, then primary connections are connections to IPv6
10826 peer addresses (while spare connections use IPv4 addresses).
10827 Similarly, if Squid DNS A query was answered first, then primary
10828 connections are connections to IPv4 peer addresses (while spare
10829 connections use IPv6 addresses).
10830
10831 Shorter happy_eyeballs_connect_timeout values reduce master
10832 transaction response time, potentially improving user-perceived
10833 response times (i.e., making user eyeballs happier). Longer delays
10834 reduce both concurrent connection level and server bombardment with
10835 connection requests, potentially improving overall Squid performance
10836 and reducing the chance of being blocked by servers for opening too
10837 many unused connections.
10838
10839 RFC 8305 prohibits happy_eyeballs_connect_timeout values smaller than
10840 10 (milliseconds) to "avoid congestion collapse in the presence of
10841 high packet-loss rates".
10842
10843 The following Happy Eyeballs directives place additional connection
10844 opening restrictions: happy_eyeballs_connect_gap and
10845 happy_eyeballs_connect_limit.
10846DOC_END
10847
10848NAME: happy_eyeballs_connect_gap
10849COMMENT: (msec)
10850TYPE: int
10851DEFAULT: -1
10852DEFAULT_DOC: no artificial delays between spare attempts
10853LOC: Config.happyEyeballs.connect_gap
10854DOC_START
10855 This Happy Eyeballs (RFC 8305) tuning directive specifies the
10856 minimum delay between opening spare to-server connections (to any
10857 server; i.e. across all concurrent master transactions in a Squid
10858 instance). Each SMP worker currently multiplies the configured gap
10859 by the total number of workers so that the combined spare connection
10860 opening rate of a Squid instance obeys the configured limit. The
10861 workers do not coordinate connection openings yet; a micro burst
10862 of spare connection openings may violate the configured gap.
10863
10864 This directive has similar trade-offs as
10865 happy_eyeballs_connect_timeout, but its focus is on limiting traffic
10866 amplification effects for Squid as a whole, while
10867 happy_eyeballs_connect_timeout works on an individual master
10868 transaction level.
10869
10870 The following Happy Eyeballs directives place additional connection
10871 opening restrictions: happy_eyeballs_connect_timeout and
10872 happy_eyeballs_connect_limit. See the former for related terminology.
10873DOC_END
10874
10875NAME: happy_eyeballs_connect_limit
10876TYPE: int
10877DEFAULT: -1
10878DEFAULT_DOC: no artificial limit on the number of concurrent spare attempts
10879LOC: Config.happyEyeballs.connect_limit
10880DOC_START
10881 This Happy Eyeballs (RFC 8305) tuning directive specifies the
10882 maximum number of spare to-server connections (to any server; i.e.
10883 across all concurrent master transactions in a Squid instance).
10884 Each SMP worker gets an equal share of the total limit. However,
10885 the workers do not share the actual connection counts yet, so one
10886 (busier) worker cannot "borrow" spare connection slots from another
10887 (less loaded) worker.
10888
10889 Setting this limit to zero disables concurrent use of primary and
10890 spare TCP connections: Spare connection attempts are made only after
10891 all primary attempts fail. However, Squid would still use the
10892 DNS-related optimizations of the Happy Eyeballs approach.
10893
10894 This directive has similar trade-offs as happy_eyeballs_connect_gap,
10895 but its focus is on limiting Squid overheads, while
10896 happy_eyeballs_connect_gap focuses on the origin server and peer
10897 overheads.
10898
10899 The following Happy Eyeballs directives place additional connection
10900 opening restrictions: happy_eyeballs_connect_timeout and
10901 happy_eyeballs_connect_gap. See the former for related terminology.
10902DOC_END
10903
cccac0a2 10904EOF