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AsyncJob-protect and reduce ICAP DNS lookup call chain (#1112)
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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
4bd88eb4 184# Options removed in 6.x
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185NAME: announce_file
186TYPE: obsolete
187DOC_START
188 Remove this line. Squid no longer supports this feature.
189DOC_END
190
191NAME: announce_host
192TYPE: obsolete
193DOC_START
194 Remove this line. Squid no longer supports this feature.
195DOC_END
196
197NAME: announce_period
198TYPE: obsolete
199DOC_START
200 Remove this line. Squid no longer supports this feature.
201DOC_END
202
203NAME: announce_port
204TYPE: obsolete
205DOC_START
206 Remove this line. Squid no longer supports this feature.
207DOC_END
208
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209NAME: request_entities
210TYPE: obsolete
211DOC_START
212 Remove this line. Squid now accepts HTTP/1.1 requests with bodies.
213 To simplify UI and code, Squid rejects certain HTTP/1.0 requests with bodies.
214DOC_END
215
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216# Options removed in 5.x
217NAME: dns_v4_first
218TYPE: obsolete
219DOC_START
220 Remove this line. Squid no longer supports preferential treatment of DNS A records.
221DOC_END
222
6eb545bc 223# Options removed in 4.x
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224NAME: cache_peer_domain cache_host_domain
225TYPE: obsolete
226DOC_START
227 Replace with dstdomain ACLs and cache_peer_access.
228DOC_END
229
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230NAME: ie_refresh
231TYPE: obsolete
232DOC_START
233 Remove this line. The behaviour enabled by this is no longer needed.
234DOC_END
235
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236NAME: sslproxy_cafile
237TYPE: obsolete
238DOC_START
239 Remove this line. Use tls_outgoing_options cafile= instead.
240DOC_END
241
242NAME: sslproxy_capath
243TYPE: obsolete
244DOC_START
245 Remove this line. Use tls_outgoing_options capath= instead.
246DOC_END
247
248NAME: sslproxy_cipher
249TYPE: obsolete
250DOC_START
251 Remove this line. Use tls_outgoing_options cipher= instead.
252DOC_END
253
254NAME: sslproxy_client_certificate
255TYPE: obsolete
256DOC_START
257 Remove this line. Use tls_outgoing_options cert= instead.
258DOC_END
259
260NAME: sslproxy_client_key
261TYPE: obsolete
262DOC_START
263 Remove this line. Use tls_outgoing_options key= instead.
264DOC_END
265
266NAME: sslproxy_flags
267TYPE: obsolete
268DOC_START
269 Remove this line. Use tls_outgoing_options flags= instead.
270DOC_END
271
272NAME: sslproxy_options
273TYPE: obsolete
274DOC_START
275 Remove this line. Use tls_outgoing_options options= instead.
276DOC_END
277
278NAME: sslproxy_version
279TYPE: obsolete
280DOC_START
1cc44095 281 Remove this line. Use tls_outgoing_options options= instead.
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282DOC_END
283
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284# Options removed in 3.5
285NAME: hierarchy_stoplist
286TYPE: obsolete
287DOC_START
288 Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
289DOC_END
290
a8f70484 291# Options removed in 3.4
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292NAME: log_access
293TYPE: obsolete
294DOC_START
295 Remove this line. Use acls with access_log directives to control access logging
296DOC_END
297
298NAME: log_icap
299TYPE: obsolete
300DOC_START
301 Remove this line. Use acls with icap_log directives to control icap logging
302DOC_END
303
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304# Options Removed in 3.3
305NAME: ignore_ims_on_miss
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306TYPE: obsolete
307DOC_START
2d4eefd9 308 Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
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309DOC_END
310
76f44481 311# Options Removed in 3.2
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312NAME: balance_on_multiple_ip
313TYPE: obsolete
314DOC_START
315 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, this multiple-IP algorithm is not longer relevant.
316DOC_END
317
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318NAME: chunked_request_body_max_size
319TYPE: obsolete
320DOC_START
321 Remove this line. Squid is now HTTP/1.1 compliant.
322DOC_END
323
74d81220 324NAME: dns_v4_fallback
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325TYPE: obsolete
326DOC_START
74d81220 327 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
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328DOC_END
329
74d81220 330NAME: emulate_httpd_log
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331TYPE: obsolete
332DOC_START
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333 Replace this with an access_log directive using the format 'common' or 'combined'.
334DOC_END
335
336NAME: forward_log
337TYPE: obsolete
338DOC_START
339 Use a regular access.log with ACL limiting it to MISS events.
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340DOC_END
341
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342NAME: ftp_list_width
343TYPE: obsolete
344DOC_START
345 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
346DOC_END
347
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348NAME: ignore_expect_100
349TYPE: obsolete
350DOC_START
351 Remove this line. The HTTP/1.1 feature is now fully supported by default.
352DOC_END
353
354NAME: log_fqdn
355TYPE: obsolete
356DOC_START
357 Remove this option from your config. To log FQDN use %>A in the log format.
358DOC_END
359
360NAME: log_ip_on_direct
361TYPE: obsolete
362DOC_START
363 Remove this option from your config. To log server or peer names use %<A in the log format.
364DOC_END
365
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366NAME: maximum_single_addr_tries
367TYPE: obsolete
368DOC_START
369 Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
370DOC_END
371
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372NAME: referer_log referrer_log
373TYPE: obsolete
374DOC_START
375 Replace this with an access_log directive using the format 'referrer'.
376DOC_END
377
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378NAME: update_headers
379TYPE: obsolete
380DOC_START
381 Remove this line. The feature is supported by default in storage types where update is implemented.
382DOC_END
383
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384NAME: url_rewrite_concurrency
385TYPE: obsolete
386DOC_START
387 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
388DOC_END
389
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390NAME: useragent_log
391TYPE: obsolete
392DOC_START
393 Replace this with an access_log directive using the format 'useragent'.
394DOC_END
395
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396# Options Removed in 3.1
397NAME: dns_testnames
398TYPE: obsolete
399DOC_START
400 Remove this line. DNS is no longer tested on startup.
401DOC_END
402
403NAME: extension_methods
404TYPE: obsolete
405DOC_START
406 Remove this line. All valid methods for HTTP are accepted by default.
407DOC_END
408
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409# 2.7 Options Removed/Replaced in 3.2
410NAME: zero_buffers
411TYPE: obsolete
412DOC_NONE
413
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414# 2.7 Options Removed/Replaced in 3.1
415NAME: incoming_rate
416TYPE: obsolete
417DOC_NONE
418
419NAME: server_http11
420TYPE: obsolete
421DOC_START
422 Remove this line. HTTP/1.1 is supported by default.
423DOC_END
424
425NAME: upgrade_http0.9
426TYPE: obsolete
427DOC_START
428 Remove this line. ICY/1.0 streaming protocol is supported by default.
429DOC_END
430
431NAME: zph_local zph_mode zph_option zph_parent zph_sibling
432TYPE: obsolete
433DOC_START
434 Alter these entries. Use the qos_flows directive instead.
435DOC_END
436
437# Options Removed in 3.0
438NAME: header_access
439TYPE: obsolete
440DOC_START
441 Since squid-3.0 replace with request_header_access or reply_header_access
442 depending on whether you wish to match client requests or server replies.
443DOC_END
444
445NAME: httpd_accel_no_pmtu_disc
446TYPE: obsolete
447DOC_START
448 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
449DOC_END
450
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451NAME: wais_relay_host
452TYPE: obsolete
453DOC_START
454 Replace this line with 'cache_peer' configuration.
455DOC_END
456
457NAME: wais_relay_port
458TYPE: obsolete
459DOC_START
460 Replace this line with 'cache_peer' configuration.
461DOC_END
462
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463COMMENT_START
464 OPTIONS FOR SMP
465 -----------------------------------------------------------------------------
466COMMENT_END
467
468NAME: workers
469TYPE: int
470LOC: Config.workers
471DEFAULT: 1
472DEFAULT_DOC: SMP support disabled.
473DOC_START
474 Number of main Squid processes or "workers" to fork and maintain.
475 0: "no daemon" mode, like running "squid -N ..."
476 1: "no SMP" mode, start one main Squid process daemon (default)
477 N: start N main Squid process daemons (i.e., SMP mode)
478
479 In SMP mode, each worker does nearly all what a single Squid daemon
480 does (e.g., listen on http_port and forward HTTP requests).
481DOC_END
482
483NAME: cpu_affinity_map
484TYPE: CpuAffinityMap
485LOC: Config.cpuAffinityMap
486DEFAULT: none
487DEFAULT_DOC: Let operating system decide.
488DOC_START
489 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
490
491 Sets 1:1 mapping between Squid processes and CPU cores. For example,
492
493 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
494
495 affects processes 1 through 4 only and places them on the first
496 four even cores, starting with core #1.
497
498 CPU cores are numbered starting from 1. Requires support for
499 sched_getaffinity(2) and sched_setaffinity(2) system calls.
500
501 Multiple cpu_affinity_map options are merged.
502
503 See also: workers
504DOC_END
505
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506NAME: shared_memory_locking
507TYPE: YesNoNone
508COMMENT: on|off
509LOC: Config.shmLocking
510DEFAULT: off
511DOC_START
512 Whether to ensure that all required shared memory is available by
513 "locking" that shared memory into RAM when Squid starts. The
514 alternative is faster startup time followed by slightly slower
515 performance and, if not enough RAM is actually available during
516 runtime, mysterious crashes.
517
518 SMP Squid uses many shared memory segments. These segments are
519 brought into Squid memory space using an mmap(2) system call. During
520 Squid startup, the mmap() call often succeeds regardless of whether
521 the system has enough RAM. In general, Squid cannot tell whether the
522 kernel applies this "optimistic" memory allocation policy (but
523 popular modern kernels usually use it).
524
525 Later, if Squid attempts to actually access the mapped memory
526 regions beyond what the kernel is willing to allocate, the
527 "optimistic" kernel simply kills Squid kid with a SIGBUS signal.
528 Some of the memory limits enforced by the kernel are currently
529 poorly understood: We do not know how to detect and check them. This
9603207d 530 option ensures that the mapped memory will be available.
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531
532 This option may have a positive performance side-effect: Locking
533 memory at start avoids runtime paging I/O. Paging slows Squid down.
534
535 Locking memory may require a large enough RLIMIT_MEMLOCK OS limit,
536 CAP_IPC_LOCK capability, or equivalent.
537DOC_END
538
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539NAME: hopeless_kid_revival_delay
540COMMENT: time-units
541TYPE: time_t
542LOC: Config.hopelessKidRevivalDelay
543DEFAULT: 1 hour
544DOC_START
545 Normally, when a kid process dies, Squid immediately restarts the
546 kid. A kid experiencing frequent deaths is marked as "hopeless" for
547 the duration specified by this directive. Hopeless kids are not
548 automatically restarted.
549
550 Currently, zero values are not supported because they result in
551 misconfigured SMP Squid instances running forever, endlessly
552 restarting each dying kid. To effectively disable hopeless kids
553 revival, set the delay to a huge value (e.g., 1 year).
554
555 Reconfiguration also clears all hopeless kids designations, allowing
556 for manual revival of hopeless kids.
557DOC_END
558
5473c134 559COMMENT_START
41bd17a4 560 OPTIONS FOR AUTHENTICATION
5473c134 561 -----------------------------------------------------------------------------
562COMMENT_END
563
41bd17a4 564NAME: auth_param
565TYPE: authparam
2f1431ea 566IFDEF: USE_AUTH
5c112575 567LOC: Auth::TheConfig.schemes
cccac0a2 568DEFAULT: none
569DOC_START
41bd17a4 570 This is used to define parameters for the various authentication
571 schemes supported by Squid.
cccac0a2 572
66c583dc 573 format: auth_param scheme parameter [setting]
cccac0a2 574
41bd17a4 575 The order in which authentication schemes are presented to the client is
576 dependent on the order the scheme first appears in config file. IE
577 has a bug (it's not RFC 2617 compliant) in that it will use the basic
578 scheme if basic is the first entry presented, even if more secure
579 schemes are presented. For now use the order in the recommended
580 settings section below. If other browsers have difficulties (don't
581 recognize the schemes offered even if you are using basic) either
582 put basic first, or disable the other schemes (by commenting out their
583 program entry).
cccac0a2 584
41bd17a4 585 Once an authentication scheme is fully configured, it can only be
586 shutdown by shutting squid down and restarting. Changes can be made on
587 the fly and activated with a reconfigure. I.E. You can change to a
588 different helper, but not unconfigure the helper completely.
cccac0a2 589
41bd17a4 590 Please note that while this directive defines how Squid processes
591 authentication it does not automatically activate authentication.
592 To use authentication you must in addition make use of ACLs based
593 on login name in http_access (proxy_auth, proxy_auth_regex or
594 external with %LOGIN used in the format tag). The browser will be
595 challenged for authentication on the first such acl encountered
596 in http_access processing and will also be re-challenged for new
597 login credentials if the request is being denied by a proxy_auth
598 type acl.
cccac0a2 599
41bd17a4 600 WARNING: authentication can't be used in a transparently intercepting
601 proxy as the client then thinks it is talking to an origin server and
602 not the proxy. This is a limitation of bending the TCP/IP protocol to
603 transparently intercepting port 80, not a limitation in Squid.
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604 Ports flagged 'transparent', 'intercept', or 'tproxy' have
605 authentication disabled.
cccac0a2 606
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607 === Parameters common to all schemes. ===
608
609 "program" cmdline
66c583dc 610 Specifies the command for the external authenticator.
d4806c91 611
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612 By default, each authentication scheme is not used unless a
613 program is specified.
cccac0a2 614
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615 See http://wiki.squid-cache.org/Features/AddonHelpers for
616 more details on helper operations and creating your own.
5269ec0e 617
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618 "key_extras" format
619 Specifies a string to be append to request line format for
620 the authentication helper. "Quoted" format values may contain
621 spaces and logformat %macros. In theory, any logformat %macro
622 can be used. In practice, a %macro expands as a dash (-) if
623 the helper request is sent before the required macro
624 information is available to Squid.
625
626 By default, Squid uses request formats provided in
627 scheme-specific examples below (search for %credentials).
628
629 The expanded key_extras value is added to the Squid credentials
630 cache and, hence, will affect authentication. It can be used to
2f8abb64 631 authenticate different users with identical user names (e.g.,
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632 when user authentication depends on http_port).
633
634 Avoid adding frequently changing information to key_extras. For
635 example, if you add user source IP, and it changes frequently
636 in your environment, then max_user_ip ACL is going to treat
637 every user+IP combination as a unique "user", breaking the ACL
638 and wasting a lot of memory on those user records. It will also
639 force users to authenticate from scratch whenever their IP
640 changes.
641
642 "realm" string
643 Specifies the protection scope (aka realm name) which is to be
644 reported to the client for the authentication scheme. It is
645 commonly part of the text the user will see when prompted for
646 their username and password.
647
648 For Basic the default is "Squid proxy-caching web server".
649 For Digest there is no default, this parameter is mandatory.
650 For NTLM and Negotiate this parameter is ignored.
5269ec0e 651
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652 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
653 [queue-size=N] [on-persistent-overload=action]
a56fcf0b 654 [reservation-timeout=seconds]
5269ec0e 655
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656 The maximum number of authenticator processes to spawn. If
657 you start too few Squid will have to wait for them to process
658 a backlog of credential verifications, slowing it down. When
659 password verifications are done via a (slow) network you are
660 likely to need lots of authenticator processes.
5269ec0e 661
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662 The startup= and idle= options permit some skew in the exact
663 amount run. A minimum of startup=N will begin during startup
664 and reconfigure. Squid will start more in groups of up to
665 idle=N in an attempt to meet traffic needs and to keep idle=N
666 free above those traffic needs up to the maximum.
5269ec0e 667
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668 The concurrency= option sets the number of concurrent requests
669 the helper can process. The default of 0 is used for helpers
670 who only supports one request at a time. Setting this to a
671 number greater than 0 changes the protocol used to include a
672 channel ID field first on the request/response line, allowing
673 multiple requests to be sent to the same helper in parallel
674 without waiting for the response.
cccac0a2 675
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676 Concurrency must not be set unless it's known the helper
677 supports the input format with channel-ID fields.
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679 The queue-size option sets the maximum number of queued
680 requests. A request is queued when no existing child can
681 accept it due to concurrency limit and no new child can be
682 started due to numberofchildren limit. The default maximum is
683 2*numberofchildren. Squid is allowed to temporarily exceed the
684 configured maximum, marking the affected helper as
685 "overloaded". If the helper overload lasts more than 3
686 minutes, the action prescribed by the on-persistent-overload
687 option applies.
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688
689 The on-persistent-overload=action option specifies Squid
690 reaction to a new helper request arriving when the helper
691 has been overloaded for more that 3 minutes already. The number
692 of queued requests determines whether the helper is overloaded
693 (see the queue-size option).
694
695 Two actions are supported:
696
697 die Squid worker quits. This is the default behavior.
698
699 ERR Squid treats the helper request as if it was
700 immediately submitted, and the helper immediately
701 replied with an ERR response. This action has no effect
702 on the already queued and in-progress helper requests.
6825b101 703
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704 NOTE: NTLM and Negotiate schemes do not support concurrency
705 in the Squid code module even though some helpers can.
307b83b7 706
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707 The reservation-timeout=seconds option allows NTLM and Negotiate
708 helpers to forget about clients that abandon their in-progress
709 connection authentication without closing the connection. The
710 timeout is measured since the last helper response received by
711 Squid for the client. Fractional seconds are not supported.
712
713 After the timeout, the helper will be used for other clients if
714 there are no unreserved helpers available. In the latter case,
715 the old client attempt to resume authentication will not be
716 forwarded to the helper (and the client should open a new HTTP
717 connection and retry authentication from scratch).
718
719 By default, reservations do not expire and clients that keep
720 their connections open without completing authentication may
721 exhaust all NTLM and Negotiate helpers.
722
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723 "keep_alive" on|off
724 If you experience problems with PUT/POST requests when using
725 the NTLM or Negotiate schemes then you can try setting this
726 to off. This will cause Squid to forcibly close the connection
727 on the initial request where the browser asks which schemes
728 are supported by the proxy.
9e7dbc51 729
b2b09838 730 For Basic and Digest this parameter is ignored.
d2a89ac1 731
66c583dc 732 "utf8" on|off
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733 Useful for sending credentials to authentication backends that
734 expect UTF-8 encoding (e.g., LDAP).
735
736 When this option is enabled, Squid uses HTTP Accept-Language
737 request header to guess the received credentials encoding
738 (ISO-Latin-1, CP1251, or UTF-8) and then converts the first
739 two encodings into UTF-8.
740
741 When this option is disabled and by default, Squid sends
742 credentials in their original (i.e. received) encoding.
743
744 This parameter is only honored for Basic and Digest schemes.
745 For Basic, the entire username:password credentials are
746 checked and, if necessary, re-encoded. For Digest -- just the
747 username component. For NTLM and Negotiate schemes, this
748 parameter is ignored.
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749
750IF HAVE_AUTH_MODULE_BASIC
751 === Basic authentication parameters ===
752
41bd17a4 753 "credentialsttl" timetolive
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754 Specifies how long squid assumes an externally validated
755 username:password pair is valid for - in other words how
756 often the helper program is called for that user. Set this
757 low to force revalidation with short lived passwords.
cccac0a2 758
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759 NOTE: setting this high does not impact your susceptibility
760 to replay attacks unless you are using an one-time password
761 system (such as SecureID). If you are using such a system,
762 you will be vulnerable to replay attacks unless you also
763 use the max_user_ip ACL in an http_access rule.
cccac0a2 764
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765 "casesensitive" on|off
766 Specifies if usernames are case sensitive. Most user databases
767 are case insensitive allowing the same username to be spelled
768 using both lower and upper case letters, but some are case
769 sensitive. This makes a big difference for user_max_ip ACL
770 processing and similar.
cccac0a2 771
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772ENDIF
773IF HAVE_AUTH_MODULE_DIGEST
774 === Digest authentication parameters ===
cccac0a2 775
41bd17a4 776 "nonce_garbage_interval" timeinterval
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777 Specifies the interval that nonces that have been issued
778 to client_agent's are checked for validity.
cccac0a2 779
41bd17a4 780 "nonce_max_duration" timeinterval
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781 Specifies the maximum length of time a given nonce will be
782 valid for.
cccac0a2 783
41bd17a4 784 "nonce_max_count" number
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785 Specifies the maximum number of times a given nonce can be
786 used.
cccac0a2 787
41bd17a4 788 "nonce_strictness" on|off
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789 Determines if squid requires strict increment-by-1 behavior
790 for nonce counts, or just incrementing (off - for use when
791 user agents generate nonce counts that occasionally miss 1
792 (ie, 1,2,4,6)). Default off.
cccac0a2 793
41bd17a4 794 "check_nonce_count" on|off
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795 This directive if set to off can disable the nonce count check
796 completely to work around buggy digest qop implementations in
797 certain mainstream browser versions. Default on to check the
798 nonce count to protect from authentication replay attacks.
cccac0a2 799
41bd17a4 800 "post_workaround" on|off
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801 This is a workaround to certain buggy browsers who send an
802 incorrect request digest in POST requests when reusing the
803 same nonce as acquired earlier on a GET request.
cccac0a2 804
66c583dc 805ENDIF
527ee50d 806
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807 === Example Configuration ===
808
809 This configuration displays the recommended authentication scheme
810 order from most to least secure with recommended minimum configuration
811 settings for each scheme:
e0855596 812
41bd17a4 813#auth_param negotiate program <uncomment and complete this line to activate>
48d54e4d 814#auth_param negotiate children 20 startup=0 idle=1
e0855596 815#
66c583dc 816#auth_param digest program <uncomment and complete this line to activate>
48d54e4d 817#auth_param digest children 20 startup=0 idle=1
41bd17a4 818#auth_param digest realm Squid proxy-caching web server
819#auth_param digest nonce_garbage_interval 5 minutes
820#auth_param digest nonce_max_duration 30 minutes
821#auth_param digest nonce_max_count 50
e0855596 822#
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823#auth_param ntlm program <uncomment and complete this line to activate>
824#auth_param ntlm children 20 startup=0 idle=1
66c583dc 825#
41bd17a4 826#auth_param basic program <uncomment and complete this line>
6f4d3ed6 827#auth_param basic children 5 startup=5 idle=1
41bd17a4 828#auth_param basic credentialsttl 2 hours
41bd17a4 829DOC_END
cccac0a2 830
41bd17a4 831NAME: authenticate_cache_garbage_interval
5db226c8 832IFDEF: USE_AUTH
41bd17a4 833TYPE: time_t
834DEFAULT: 1 hour
00ef8d82 835LOC: Auth::TheConfig.garbageCollectInterval
41bd17a4 836DOC_START
837 The time period between garbage collection across the username cache.
4ded749e 838 This is a trade-off between memory utilization (long intervals - say
41bd17a4 839 2 days) and CPU (short intervals - say 1 minute). Only change if you
840 have good reason to.
841DOC_END
cccac0a2 842
41bd17a4 843NAME: authenticate_ttl
5db226c8 844IFDEF: USE_AUTH
41bd17a4 845TYPE: time_t
846DEFAULT: 1 hour
00ef8d82 847LOC: Auth::TheConfig.credentialsTtl
41bd17a4 848DOC_START
849 The time a user & their credentials stay in the logged in
850 user cache since their last request. When the garbage
851 interval passes, all user credentials that have passed their
852 TTL are removed from memory.
853DOC_END
cccac0a2 854
41bd17a4 855NAME: authenticate_ip_ttl
5db226c8 856IFDEF: USE_AUTH
41bd17a4 857TYPE: time_t
00ef8d82 858LOC: Auth::TheConfig.ipTtl
c35dd848 859DEFAULT: 1 second
41bd17a4 860DOC_START
861 If you use proxy authentication and the 'max_user_ip' ACL,
862 this directive controls how long Squid remembers the IP
863 addresses associated with each user. Use a small value
864 (e.g., 60 seconds) if your users might change addresses
4ded749e 865 quickly, as is the case with dialup. You might be safe
41bd17a4 866 using a larger value (e.g., 2 hours) in a corporate LAN
867 environment with relatively static address assignments.
868DOC_END
cccac0a2 869
3d1e3e43 870COMMENT_START
871 ACCESS CONTROLS
872 -----------------------------------------------------------------------------
873COMMENT_END
874
41bd17a4 875NAME: external_acl_type
876TYPE: externalAclHelper
877LOC: Config.externalAclHelperList
cccac0a2 878DEFAULT: none
cccac0a2 879DOC_START
41bd17a4 880 This option defines external acl classes using a helper program
881 to look up the status
cccac0a2 882
262eaf9a 883 external_acl_type name [options] FORMAT /path/to/helper [helper arguments]
cccac0a2 884
41bd17a4 885 Options:
cccac0a2 886
41bd17a4 887 ttl=n TTL in seconds for cached results (defaults to 3600
cd0fd8a9 888 for 1 hour)
4f8d0a65 889
41bd17a4 890 negative_ttl=n
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891 TTL for cached negative lookups (default same
892 as ttl)
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893
894 grace=n Percentage remaining of TTL where a refresh of a
895 cached entry should be initiated without needing to
896 wait for a new reply. (default is for no grace period)
897
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898 cache=n The maximum number of entries in the result cache. The
899 default limit is 262144 entries. Each cache entry usually
900 consumes at least 256 bytes. Squid currently does not remove
901 expired cache entries until the limit is reached, so a proxy
902 will sooner or later reach the limit. The expanded FORMAT
903 value is used as the cache key, so if the details in FORMAT
904 are highly variable, a larger cache may be needed to produce
905 reduction in helper load.
4f8d0a65 906
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907 children-max=n
908 Maximum number of acl helper processes spawned to service
2ccfb9a7 909 external acl lookups of this type. (default 5)
4f8d0a65 910
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911 children-startup=n
912 Minimum number of acl helper processes to spawn during
913 startup and reconfigure to service external acl lookups
914 of this type. (default 0)
4f8d0a65 915
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916 children-idle=n
917 Number of acl helper processes to keep ahead of traffic
918 loads. Squid will spawn this many at once whenever load
919 rises above the capabilities of existing processes.
920 Up to the value of children-max. (default 1)
4f8d0a65 921
41bd17a4 922 concurrency=n concurrency level per process. Only used with helpers
923 capable of processing more than one query at a time.
4f8d0a65 924
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925 queue-size=N The queue-size option sets the maximum number of
926 queued requests. A request is queued when no existing
927 helper can accept it due to concurrency limit and no
928 new helper can be started due to children-max limit.
929 If the queued requests exceed queue size, the acl is
930 ignored. The default value is set to 2*children-max.
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931
932 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers.
933
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934 ipv4 / ipv6 IP protocol used to communicate with this helper.
935 The default is to auto-detect IPv6 and use it when available.
cccac0a2 936
4f8d0a65 937
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938 FORMAT is a series of %macro codes. See logformat directive for a full list
939 of the accepted codes. Although note that at the time of any external ACL
940 being tested data may not be available and thus some %macro expand to '-'.
941
942 In addition to the logformat codes; when processing external ACLs these
943 additional macros are made available:
7b0ca1e8 944
ec2d5242 945 %ACL The name of the ACL being tested.
ec2d5242 946
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947 %DATA The ACL arguments specified in the referencing config
948 'acl ... external' line, separated by spaces (an
949 "argument string"). see acl external.
950
951 If there are no ACL arguments %DATA expands to '-'.
952
953 If you do not specify a DATA macro inside FORMAT,
954 Squid automatically appends %DATA to your FORMAT.
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955 Note that Squid-3.x may expand %DATA to whitespace
956 or nothing in this case.
cd0fd8a9 957
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958 By default, Squid applies URL-encoding to each ACL
959 argument inside the argument string. If an explicit
960 encoding modifier is used (e.g., %#DATA), then Squid
961 encodes the whole argument string as a single token
962 (e.g., with %#DATA, spaces between arguments become
963 %20).
964
2f8abb64 965 If SSL is enabled, the following formatting codes become available:
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966
967 %USER_CERT SSL User certificate in PEM format
968 %USER_CERTCHAIN SSL User certificate chain in PEM format
969 %USER_CERT_xx SSL User certificate subject attribute xx
970 %USER_CA_CERT_xx SSL User certificate issuer attribute xx
971
972
973 NOTE: all other format codes accepted by older Squid versions
974 are deprecated.
0db8942f 975
cccac0a2 976
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977 General request syntax:
978
0638f4a2 979 [channel-ID] FORMAT-values
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980
981
982 FORMAT-values consists of transaction details expanded with
983 whitespace separation per the config file FORMAT specification
984 using the FORMAT macros listed above.
985
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986 Request values sent to the helper are URL escaped to protect
987 each value in requests against whitespaces.
988
989 If using protocol=2.5 then the request sent to the helper is not
990 URL escaped to protect against whitespace.
991
992 NOTE: protocol=3.0 is deprecated as no longer necessary.
993
994 When using the concurrency= option the protocol is changed by
995 introducing a query channel tag in front of the request/response.
996 The query channel tag is a number between 0 and concurrency-1.
997 This value must be echoed back unchanged to Squid as the first part
998 of the response relating to its request.
999
1000
1001 The helper receives lines expanded per the above format specification
1002 and for each input line returns 1 line starting with OK/ERR/BH result
1003 code and optionally followed by additional keywords with more details.
1004
cccac0a2 1005
41bd17a4 1006 General result syntax:
cccac0a2 1007
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1008 [channel-ID] result keyword=value ...
1009
1010 Result consists of one of the codes:
1011
1012 OK
1013 the ACL test produced a match.
1014
1015 ERR
1016 the ACL test does not produce a match.
1017
1018 BH
4ded749e 1019 An internal error occurred in the helper, preventing
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1020 a result being identified.
1021
1022 The meaning of 'a match' is determined by your squid.conf
1023 access control configuration. See the Squid wiki for details.
cccac0a2 1024
41bd17a4 1025 Defined keywords:
cccac0a2 1026
41bd17a4 1027 user= The users name (login)
5269ec0e 1028
41bd17a4 1029 password= The users password (for login= cache_peer option)
5269ec0e 1030
05e52854 1031 message= Message describing the reason for this response.
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1032 Available as %o in error pages.
1033 Useful on (ERR and BH results).
1034
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1035 tag= Apply a tag to a request. Only sets a tag once,
1036 does not alter existing tags.
5269ec0e 1037
41bd17a4 1038 log= String to be logged in access.log. Available as
cd0fd8a9 1039 %ea in logformat specifications.
934b03fc 1040
cd0fd8a9 1041 clt_conn_tag= Associates a TAG with the client TCP connection.
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1042 Please see url_rewrite_program related documentation
1043 for this kv-pair.
457857fe 1044
05e52854 1045 Any keywords may be sent on any response whether OK, ERR or BH.
6a566b9c 1046
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1047 All response keyword values need to be a single token with URL
1048 escaping, or enclosed in double quotes (") and escaped using \ on
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1049 any double quotes or \ characters within the value. The wrapping
1050 double quotes are removed before the value is interpreted by Squid.
1051 \r and \n are also replace by CR and LF.
1e5562e3 1052
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1053 Some example key values:
1054
5269ec0e 1055 user=John%20Smith
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1056 user="John Smith"
1057 user="J. \"Bob\" Smith"
cccac0a2 1058DOC_END
1059
41bd17a4 1060NAME: acl
1061TYPE: acl
1062LOC: Config.aclList
cb4f4424 1063IF USE_OPENSSL
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CT
1064DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
1065DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
1066DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
1067DEFAULT: 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
1068DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
1069ENDIF
1f5bd0a4 1070DEFAULT: all src all
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1071DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
1072DEFAULT: localhost src 127.0.0.1/32 ::1
d959846f 1073DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1/128 ::/128
2c56ee3c 1074DEFAULT: CONNECT method CONNECT
29503899 1075DEFAULT_DOC: ACLs all, manager, localhost, to_localhost, and CONNECT are predefined.
cccac0a2 1076DOC_START
41bd17a4 1077 Defining an Access List
cccac0a2 1078
9603207d 1079 Every access list definition must begin with an aclname and acltype,
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1080 followed by either type-specific arguments or a quoted filename that
1081 they are read from.
cccac0a2 1082
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1083 acl aclname acltype argument ...
1084 acl aclname acltype "file" ...
cccac0a2 1085
375eeb3b 1086 When using "file", the file should contain one item per line.
cccac0a2 1087
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1088
1089 ACL Options
1090
1091 Some acl types supports options which changes their default behaviour:
0f987978
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1092
1093 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
1094 case-insensitive, use the -i option. To return case-sensitive
1095 use the +i option between patterns, or make a new ACL line
9603207d 1096 without -i.
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CT
1097
1098 -n Disable lookups and address type conversions. If lookup or
1099 conversion is required because the parameter type (IP or
1100 domain name) does not match the message address type (domain
1101 name or IP), then the ACL would immediately declare a mismatch
1102 without any warnings or lookups.
1103
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1104 -m[=delimiters]
1105 Perform a list membership test, interpreting values as
1106 comma-separated token lists and matching against individual
9603207d 1107 tokens instead of whole values.
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1108 The optional "delimiters" parameter specifies one or more
1109 alternative non-alphanumeric delimiter characters.
1110 non-alphanumeric delimiter characters.
1111
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1112 -- Used to stop processing all options, in the case the first acl
1113 value has '-' character as first character (for example the '-'
1114 is a valid domain name)
cccac0a2 1115
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FC
1116 Some acl types require suspending the current request in order
1117 to access some external data source.
1118 Those which do are marked with the tag [slow], those which
1119 don't are marked as [fast].
1120 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
1121 for further information
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1122
1123 ***** ACL TYPES AVAILABLE *****
1124
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1125 acl aclname src ip-address/mask ... # clients IP address [fast]
1126 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
0f987978 1127 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
1e40905d 1128 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
cccac0a2 1129
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1130if USE_SQUID_EUI
1131 acl aclname arp mac-address ...
1132 acl aclname eui64 eui64-address ...
b3567eb5 1133 # [fast]
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1134 # MAC (EUI-48) and EUI-64 addresses use xx:xx:xx:xx:xx:xx notation.
1135 #
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1136 # The 'arp' ACL code is not portable to all operating systems.
1137 # It works on Linux, Solaris, Windows, FreeBSD, and some other
1138 # BSD variants.
41bd17a4 1139 #
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1140 # The eui_lookup directive is required to be 'on' (the default)
1141 # and Squid built with --enable-eui for MAC/EUI addresses to be
1142 # available for this ACL.
1143 #
1144 # Squid can only determine the MAC/EUI address for IPv4
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1145 # clients that are on the same subnet. If the client is on a
1146 # different subnet, then Squid cannot find out its address.
1147 #
a85f0df5 1148 # IPv6 protocol does not contain ARP. MAC/EUI is either
abe01913 1149 # encoded directly in the IPv6 address or not available.
a85f0df5 1150endif
653d9927 1151 acl aclname clientside_mark mark[/mask] ...
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1152 # matches CONNMARK of an accepted connection [fast]
1153 # DEPRECATED. Use the 'client_connection_mark' instead.
1154
1155 acl aclname client_connection_mark mark[/mask] ...
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A
1156 # matches CONNMARK of an accepted connection [fast]
1157 #
1158 # mark and mask are unsigned integers (hex, octal, or decimal).
1159 # If multiple marks are given, then the ACL matches if at least
1160 # one mark matches.
1161 #
1162 # Uses netfilter-conntrack library.
1163 # Requires building Squid with --enable-linux-netfilter.
1164 #
1165 # The client, various intermediaries, and Squid itself may set
1166 # CONNMARK at various times. The last CONNMARK set wins. This ACL
1167 # checks the mark present on an accepted connection or set by
1168 # Squid afterwards, depending on the ACL check timing. This ACL
1169 # effectively ignores any mark set by other agents after Squid has
1170 # accepted the connection.
1171
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1172 acl aclname srcdomain .foo.com ...
1173 # reverse lookup, from client IP [slow]
0f987978 1174 acl aclname dstdomain [-n] .foo.com ...
e38c7724 1175 # Destination server from URL [fast]
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FC
1176 acl aclname srcdom_regex [-i] \.foo\.com ...
1177 # regex matching client name [slow]
0f987978 1178 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
e38c7724 1179 # regex matching server [fast]
b3567eb5 1180 #
41bd17a4 1181 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
1182 # based URL is used and no match is found. The name "none" is used
1183 # if the reverse lookup fails.
9bc73deb 1184
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1185 acl aclname src_as number ...
1186 acl aclname dst_as number ...
b3567eb5 1187 # [fast]
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1188 # Except for access control, AS numbers can be used for
1189 # routing of requests to specific caches. Here's an
1190 # example for routing all requests for AS#1241 and only
1191 # those to mycache.mydomain.net:
1192 # acl asexample dst_as 1241
1193 # cache_peer_access mycache.mydomain.net allow asexample
1194 # cache_peer_access mycache_mydomain.net deny all
7f7db318 1195
6db78a1a 1196 acl aclname peername myPeer ...
a85f0df5 1197 acl aclname peername_regex [-i] regex-pattern ...
b3567eb5 1198 # [fast]
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1199 # match against a named cache_peer entry
1200 # set unique name= on cache_peer lines for reliable use.
1201
375eeb3b 1202 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
b3567eb5 1203 # [fast]
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1204 # day-abbrevs:
1205 # S - Sunday
1206 # M - Monday
1207 # T - Tuesday
1208 # W - Wednesday
1209 # H - Thursday
1210 # F - Friday
1211 # A - Saturday
1212 # h1:m1 must be less than h2:m2
1213
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FC
1214 acl aclname url_regex [-i] ^http:// ...
1215 # regex matching on whole URL [fast]
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1216 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
1217 # regex matching on URL login field
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FC
1218 acl aclname urlpath_regex [-i] \.gif$ ...
1219 # regex matching on URL path [fast]
e988aa40 1220
b3567eb5 1221 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
2f8abb64 1222 # ranges are allowed
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AJ
1223 acl aclname localport 3128 ... # TCP port the client connected to [fast]
1224 # NP: for interception mode this is usually '80'
1225
3cc0f4e7 1226 acl aclname myportname 3128 ... # *_port name [fast]
e988aa40 1227
b3567eb5 1228 acl aclname proto HTTP FTP ... # request protocol [fast]
9603207d 1229
b3567eb5 1230 acl aclname method GET POST ... # HTTP request method [fast]
e988aa40 1231
9603207d 1232 acl aclname http_status 200 301 500- 400-403 ...
b3567eb5 1233 # status code in reply [fast]
e988aa40 1234
375eeb3b 1235 acl aclname browser [-i] regexp ...
b3567eb5 1236 # pattern match on User-Agent header (see also req_header below) [fast]
e988aa40 1237
375eeb3b 1238 acl aclname referer_regex [-i] regexp ...
b3567eb5 1239 # pattern match on Referer header [fast]
41bd17a4 1240 # Referer is highly unreliable, so use with care
e988aa40 1241
d4c6acac 1242 acl aclname ident [-i] username ...
41bd17a4 1243 acl aclname ident_regex [-i] pattern ...
b3567eb5 1244 # string match on ident output [slow]
41bd17a4 1245 # use REQUIRED to accept any non-null ident.
cf5cc17e 1246
41bd17a4 1247 acl aclname proxy_auth [-i] username ...
1248 acl aclname proxy_auth_regex [-i] pattern ...
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1249 # perform http authentication challenge to the client and match against
1250 # supplied credentials [slow]
1251 #
1252 # takes a list of allowed usernames.
41bd17a4 1253 # use REQUIRED to accept any valid username.
1254 #
b3567eb5 1255 # Will use proxy authentication in forward-proxy scenarios, and plain
2f8abb64 1256 # http authentication in reverse-proxy scenarios
b3567eb5 1257 #
41bd17a4 1258 # NOTE: when a Proxy-Authentication header is sent but it is not
1259 # needed during ACL checking the username is NOT logged
1260 # in access.log.
1261 #
1262 # NOTE: proxy_auth requires a EXTERNAL authentication program
1263 # to check username/password combinations (see
1264 # auth_param directive).
1265 #
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1266 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
1267 # as the browser needs to be configured for using a proxy in order
41bd17a4 1268 # to respond to proxy authentication.
8e8d4f30 1269
41bd17a4 1270 acl aclname snmp_community string ...
b3567eb5 1271 # A community string to limit access to your SNMP Agent [fast]
41bd17a4 1272 # Example:
1273 #
1274 # acl snmppublic snmp_community public
934b03fc 1275
41bd17a4 1276 acl aclname maxconn number
1277 # This will be matched when the client's IP address has
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1278 # more than <number> TCP connections established. [fast]
1279 # NOTE: This only measures direct TCP links so X-Forwarded-For
1280 # indirect clients are not counted.
1e5562e3 1281
41bd17a4 1282 acl aclname max_user_ip [-s] number
1283 # This will be matched when the user attempts to log in from more
1284 # than <number> different ip addresses. The authenticate_ip_ttl
b3567eb5 1285 # parameter controls the timeout on the ip entries. [fast]
41bd17a4 1286 # If -s is specified the limit is strict, denying browsing
1287 # from any further IP addresses until the ttl has expired. Without
1288 # -s Squid will just annoy the user by "randomly" denying requests.
1289 # (the counter is reset each time the limit is reached and a
1290 # request is denied)
1291 # NOTE: in acceleration mode or where there is mesh of child proxies,
1292 # clients may appear to come from multiple addresses if they are
1293 # going through proxy farms, so a limit of 1 may cause user problems.
cccac0a2 1294
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1295 acl aclname random probability
1296 # Pseudo-randomly match requests. Based on the probability given.
1297 # Probability may be written as a decimal (0.333), fraction (1/3)
1298 # or ratio of matches:non-matches (3:5).
1299
375eeb3b 1300 acl aclname req_mime_type [-i] mime-type ...
41bd17a4 1301 # regex match against the mime type of the request generated
1302 # by the client. Can be used to detect file upload or some
b3567eb5 1303 # types HTTP tunneling requests [fast]
41bd17a4 1304 # NOTE: This does NOT match the reply. You cannot use this
1305 # to match the returned file type.
cccac0a2 1306
41bd17a4 1307 acl aclname req_header header-name [-i] any\.regex\.here
1308 # regex match against any of the known request headers. May be
1309 # thought of as a superset of "browser", "referer" and "mime-type"
b3567eb5 1310 # ACL [fast]
cccac0a2 1311
375eeb3b 1312 acl aclname rep_mime_type [-i] mime-type ...
41bd17a4 1313 # regex match against the mime type of the reply received by
1314 # squid. Can be used to detect file download or some
b3567eb5 1315 # types HTTP tunneling requests. [fast]
41bd17a4 1316 # NOTE: This has no effect in http_access rules. It only has
1317 # effect in rules that affect the reply data stream such as
1318 # http_reply_access.
cccac0a2 1319
41bd17a4 1320 acl aclname rep_header header-name [-i] any\.regex\.here
1321 # regex match against any of the known reply headers. May be
1322 # thought of as a superset of "browser", "referer" and "mime-type"
b3567eb5 1323 # ACLs [fast]
cccac0a2 1324
375eeb3b 1325 acl aclname external class_name [arguments...]
41bd17a4 1326 # external ACL lookup via a helper class defined by the
b3567eb5 1327 # external_acl_type directive [slow]
cccac0a2 1328
41bd17a4 1329 acl aclname user_cert attribute values...
1330 # match against attributes in a user SSL certificate
2927ae41 1331 # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
cccac0a2 1332
41bd17a4 1333 acl aclname ca_cert attribute values...
1334 # match against attributes a users issuing CA SSL certificate
2927ae41 1335 # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
cccac0a2 1336
d4c6acac 1337 acl aclname ext_user [-i] username ...
41bd17a4 1338 acl aclname ext_user_regex [-i] pattern ...
b3567eb5 1339 # string match on username returned by external acl helper [slow]
41bd17a4 1340 # use REQUIRED to accept any non-null user name.
b3567eb5 1341
0ab50441 1342 acl aclname tag tagvalue ...
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1343 # string match on tag returned by external acl helper [fast]
1344 # DEPRECATED. Only the first tag will match with this ACL.
1345 # Use the 'note' ACL instead for handling multiple tag values.
cccac0a2 1346
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1347 acl aclname hier_code codename ...
1348 # string match against squid hierarchy code(s); [fast]
1349 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1350 #
1351 # NOTE: This has no effect in http_access rules. It only has
1352 # effect in rules that affect the reply data stream such as
1353 # http_reply_access.
1354
76ee67ac 1355 acl aclname note [-m[=delimiters]] name [value ...]
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1356 # match transaction annotation [fast]
1357 # Without values, matches any annotation with a given name.
1358 # With value(s), matches any annotation with a given name that
1359 # also has one of the given values.
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CT
1360 # If the -m flag is used, then the value of the named
1361 # annotation is interpreted as a list of tokens, and the ACL
1362 # matches individual name=token pairs rather than whole
1363 # name=value pairs. See "ACL Options" above for more info.
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CT
1364 # Annotation sources include note and adaptation_meta directives
1365 # as well as helper and eCAP responses.
1366
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1367 acl aclname annotate_transaction [-m[=delimiters]] key=value ...
1368 acl aclname annotate_transaction [-m[=delimiters]] key+=value ...
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CT
1369 # Always matches. [fast]
1370 # Used for its side effect: This ACL immediately adds a
1371 # key=value annotation to the current master transaction.
1372 # The added annotation can then be tested using note ACL and
1373 # logged (or sent to helpers) using %note format code.
1374 #
1375 # Annotations can be specified using replacement and addition
1376 # formats. The key=value form replaces old same-key annotation
1377 # value(s). The key+=value form appends a new value to the old
1378 # same-key annotation. Both forms create a new key=value
1379 # annotation if no same-key annotation exists already. If
1380 # -m flag is used, then the value is interpreted as a list
1381 # and the annotation will contain key=token pair(s) instead of the
1382 # whole key=value pair.
1383 #
1384 # This ACL is especially useful for recording complex multi-step
1385 # ACL-driven decisions. For example, the following configuration
1386 # avoids logging transactions accepted after aclX matched:
1387 #
1388 # # First, mark transactions accepted after aclX matched
1389 # acl markSpecial annotate_transaction special=true
1390 # http_access allow acl001
1391 # ...
1392 # http_access deny acl100
1393 # http_access allow aclX markSpecial
1394 #
1395 # # Second, do not log marked transactions:
1396 # acl markedSpecial note special true
1397 # access_log ... deny markedSpecial
1398 #
1399 # # Note that the following would not have worked because aclX
1400 # # alone does not determine whether the transaction was allowed:
1401 # access_log ... deny aclX # Wrong!
1402 #
1403 # Warning: This ACL annotates the transaction even when negated
1404 # and even if subsequent ACLs fail to match. For example, the
1405 # following three rules will have exactly the same effect as far
1406 # as annotations set by the "mark" ACL are concerned:
1407 #
1408 # some_directive acl1 ... mark # rule matches if mark is reached
1409 # some_directive acl1 ... !mark # rule never matches
1410 # some_directive acl1 ... mark !all # rule never matches
1411
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CT
1412 acl aclname annotate_client [-m[=delimiters]] key=value ...
1413 acl aclname annotate_client [-m[=delimiters]] key+=value ...
75d47340 1414 #
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CT
1415 # Always matches. [fast]
1416 # Used for its side effect: This ACL immediately adds a
1417 # key=value annotation to the current client-to-Squid
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CT
1418 # connection. Connection annotations are propagated to the current
1419 # and all future master transactions on the annotated connection.
1420 # See the annotate_transaction ACL for details.
1421 #
1422 # For example, the following configuration avoids rewriting URLs
1423 # of transactions bumped by SslBump:
1424 #
1425 # # First, mark bumped connections:
1426 # acl markBumped annotate_client bumped=true
1427 # ssl_bump peek acl1
1428 # ssl_bump stare acl2
1429 # ssl_bump bump acl3 markBumped
1430 # ssl_bump splice all
1431 #
1432 # # Second, do not send marked transactions to the redirector:
1433 # acl markedBumped note bumped true
1434 # url_rewrite_access deny markedBumped
1435 #
1436 # # Note that the following would not have worked because acl3 alone
1437 # # does not determine whether the connection is going to be bumped:
1438 # url_rewrite_access deny acl3 # Wrong!
1439
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1440 acl aclname adaptation_service service ...
1441 # Matches the name of any icap_service, ecap_service,
1442 # adaptation_service_set, or adaptation_service_chain that Squid
1443 # has used (or attempted to use) for the master transaction.
1444 # This ACL must be defined after the corresponding adaptation
1445 # service is named in squid.conf. This ACL is usable with
1446 # adaptation_meta because it starts matching immediately after
1447 # the service has been selected for adaptation.
1448
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1449 acl aclname transaction_initiator initiator ...
1450 # Matches transaction's initiator [fast]
1451 #
1452 # Supported initiators are:
1453 # esi: matches transactions fetching ESI resources
1454 # certificate-fetching: matches transactions fetching
1455 # a missing intermediate TLS certificate
1456 # cache-digest: matches transactions fetching Cache Digests
1457 # from a cache_peer
1458 # htcp: matches HTCP requests from peers
1459 # icp: matches ICP requests to peers
1460 # icmp: matches ICMP RTT database (NetDB) requests to peers
1461 # asn: matches asns db requests
1462 # internal: matches any of the above
1463 # client: matches transactions containing an HTTP or FTP
1464 # client request received at a Squid *_port
1465 # all: matches any transaction, including internal transactions
1466 # without a configurable initiator and hopefully rare
1467 # transactions without a known-to-Squid initiator
1468 #
1469 # Multiple initiators are ORed.
1470
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1471 acl aclname has component
1472 # matches a transaction "component" [fast]
1473 #
1474 # Supported transaction components are:
1475 # request: transaction has a request header (at least)
1476 # response: transaction has a response header (at least)
1477 # ALE: transaction has an internally-generated Access Log Entry
1478 # structure; bugs notwithstanding, all transaction have it
1479 #
1480 # For example, the following configuration helps when dealing with HTTP
1481 # clients that close connections without sending a request header:
1482 #
1483 # acl hasRequest has request
1484 # acl logMe note important_transaction
1485 # # avoid "logMe ACL is used in context without an HTTP request" warnings
1486 # access_log ... logformat=detailed hasRequest logMe
1487 # # log request-less transactions, instead of ignoring them
1488 # access_log ... logformat=brief !hasRequest
1489 #
1490 # Multiple components are not supported for one "acl" rule, but
1491 # can be specified (and are ORed) using multiple same-name rules:
1492 #
1493 # # OK, this strange logging daemon needs request or response,
1494 # # but can work without either a request or a response:
1495 # acl hasWhatMyLoggingDaemonNeeds has request
1496 # acl hasWhatMyLoggingDaemonNeeds has response
1497
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1498acl aclname at_step step
1499 # match against the current request processing step [fast]
1500 # Valid steps are:
1501 # GeneratingCONNECT: Generating HTTP CONNECT request headers
1502IF USE_OPENSSL
1503 # The following ssl_bump processing steps are recognized:
1504 # SslBump1: After getting TCP-level and HTTP CONNECT info.
1505 # SslBump2: After getting SSL Client Hello info.
1506 # SslBump3: After getting SSL Server Hello info.
1507ENDIF
1508
cb4f4424 1509IF USE_OPENSSL
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CT
1510 acl aclname ssl_error errorname
1511 # match against SSL certificate validation error [fast]
cf1c09f6 1512 #
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AR
1513 # When used with sslproxy_cert_error, this ACL tests a single
1514 # certificate validation error currently being evaluated by that
1515 # directive. When used with slproxy_cert_sign or sslproxy_cert_adapt,
1516 # the ACL tests all past certificate validation errors associated with
1517 # the current Squid-to-server connection (attempt). This ACL is not yet
1518 # supported for use with other directives.
1519 #
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1520 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1521 # template file.
cf1c09f6 1522 #
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1523 # The following can be used as shortcuts for certificate properties:
1524 # [ssl::]certHasExpired: the "not after" field is in the past
1525 # [ssl::]certNotYetValid: the "not before" field is in the future
1526 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1527 # [ssl::]certSelfSigned: The certificate is self signed.
1528 # [ssl::]certDomainMismatch: The certificate CN domain does not
1529 # match the name the name of the host we are connecting to.
1530 #
1531 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1532 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1533 # predefined ACLs, just like the 'all' ACL.
00352183 1534
72b12f9e 1535 acl aclname server_cert_fingerprint [-sha1] fingerprint
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AR
1536 # match against server SSL certificate fingerprint [fast]
1537 #
9603207d 1538 # The fingerprint is the digest of the DER encoded version
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AR
1539 # of the whole certificate. The user should use the form: XX:XX:...
1540 # Optional argument specifies the digest algorithm to use.
1541 # The SHA1 digest algorithm is the default and is currently
1542 # the only algorithm supported (-sha1).
5d65362c 1543
4f6990ec 1544 acl aclname ssl::server_name [option] .foo.com ...
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CT
1545 # matches server name obtained from various sources [fast]
1546 #
4f6990ec 1547 # The ACL computes server name(s) using such information sources as
9603207d 1548 # CONNECT request URI, TLS client SNI, and TLS server certificate
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CT
1549 # subject (CN and SubjectAltName). The computed server name(s) usually
1550 # change with each SslBump step, as more info becomes available:
1551 # * SNI is used as the server name instead of the request URI,
1552 # * subject name(s) from the server certificate (CN and
1553 # SubjectAltName) are used as the server names instead of SNI.
1554 #
1555 # When the ACL computes multiple server names, matching any single
1556 # computed name is sufficient for the ACL to match.
1557 #
1558 # The "none" name can be used to match transactions where the ACL
8d9e6d7f 1559 # could not compute the server name using any information source
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CT
1560 # that was both available and allowed to be used by the ACL options at
1561 # the ACL evaluation time.
1562 #
1563 # Unlike dstdomain, this ACL does not perform DNS lookups.
1564 #
9603207d 1565 # An ACL option below may be used to restrict what information
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CT
1566 # sources are used to extract the server names from:
1567 #
1568 # --client-requested
1569 # The server name is SNI regardless of what the server says.
1570 # --server-provided
1571 # The server name(s) are the certificate subject name(s), regardless
1572 # of what the client has requested. If the server certificate is
1573 # unavailable, then the name is "none".
1574 # --consensus
1575 # The server name is either SNI (if SNI matches at least one of the
1576 # certificate subject names) or "none" (otherwise). When the server
1577 # certificate is unavailable, the consensus server name is SNI.
1578 #
1579 # Combining multiple options in one ACL is a fatal configuration
1580 # error.
1581 #
1582 # For all options: If no SNI is available, then the CONNECT request
1583 # target (a.k.a. URI) is used instead of SNI (for an intercepted
1584 # connection, this target is the destination IP address).
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CT
1585
1586 acl aclname ssl::server_name_regex [-i] \.foo\.com ...
1587 # regex matches server name obtained from various sources [fast]
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CT
1588
1589 acl aclname connections_encrypted
1590 # matches transactions with all HTTP messages received over TLS
1591 # transport connections. [fast]
1592 #
1593 # The master transaction deals with HTTP messages received from
1594 # various sources. All sources used by the master transaction in the
1595 # past are considered by the ACL. The following rules define whether
1596 # a given message source taints the entire master transaction,
1597 # resulting in ACL mismatches:
1598 #
1599 # * The HTTP client transport connection is not TLS.
1600 # * An adaptation service connection-encryption flag is off.
1601 # * The peer or origin server transport connection is not TLS.
1602 #
1603 # Caching currently does not affect these rules. This cache ignorance
1604 # implies that only the current HTTP client transport and REQMOD
1605 # services status determine whether this ACL matches a from-cache
1606 # transaction. The source of the cached response does not have any
1607 # effect on future transaction that use the cached response without
1608 # revalidation. This may change.
1609 #
1610 # DNS, ICP, and HTCP exchanges during the master transaction do not
1611 # affect these rules.
cf1c09f6 1612ENDIF
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1613 acl aclname any-of acl1 acl2 ...
1614 # match any one of the acls [fast or slow]
1615 # The first matching ACL stops further ACL evaluation.
1616 #
1617 # ACLs from multiple any-of lines with the same name are ORed.
1618 # For example, A = (a1 or a2) or (a3 or a4) can be written as
1619 # acl A any-of a1 a2
1620 # acl A any-of a3 a4
1621 #
1622 # This group ACL is fast if all evaluated ACLs in the group are fast
1623 # and slow otherwise.
1624
9603207d 1625 acl aclname all-of acl1 acl2 ...
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AR
1626 # match all of the acls [fast or slow]
1627 # The first mismatching ACL stops further ACL evaluation.
1628 #
1629 # ACLs from multiple all-of lines with the same name are ORed.
1630 # For example, B = (b1 and b2) or (b3 and b4) can be written as
1631 # acl B all-of b1 b2
1632 # acl B all-of b3 b4
1633 #
1634 # This group ACL is fast if all evaluated ACLs in the group are fast
1635 # and slow otherwise.
cf1c09f6 1636
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1637 Examples:
1638 acl macaddress arp 09:00:2b:23:45:67
1639 acl myexample dst_as 1241
1640 acl password proxy_auth REQUIRED
1641 acl fileupload req_mime_type -i ^multipart/form-data$
1642 acl javascript rep_mime_type -i ^application/x-javascript$
cccac0a2 1643
47f0eaea 1644CONFIG_START
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1645#
1646# Recommended minimum configuration:
1647#
e0855596 1648
ee776778 1649# Example rule allowing access from your local networks.
1650# Adapt to list your (internal) IP networks from where browsing
1651# should be allowed
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1652acl localnet src 0.0.0.1-0.255.255.255 # RFC 1122 "this" network (LAN)
1653acl localnet src 10.0.0.0/8 # RFC 1918 local private network (LAN)
1654acl localnet src 100.64.0.0/10 # RFC 6598 shared address space (CGN)
7c392424 1655acl localnet src 169.254.0.0/16 # RFC 3927 link-local (directly plugged) machines
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1656acl localnet src 172.16.0.0/12 # RFC 1918 local private network (LAN)
1657acl localnet src 192.168.0.0/16 # RFC 1918 local private network (LAN)
1658acl localnet src fc00::/7 # RFC 4193 local private network range
1659acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
e0855596 1660
41bd17a4 1661acl SSL_ports port 443
1662acl Safe_ports port 80 # http
1663acl Safe_ports port 21 # ftp
1664acl Safe_ports port 443 # https
1665acl Safe_ports port 70 # gopher
1666acl Safe_ports port 210 # wais
1667acl Safe_ports port 1025-65535 # unregistered ports
1668acl Safe_ports port 280 # http-mgmt
1669acl Safe_ports port 488 # gss-http
1670acl Safe_ports port 591 # filemaker
1671acl Safe_ports port 777 # multiling http
47f0eaea 1672CONFIG_END
41bd17a4 1673DOC_END
cccac0a2 1674
d3d92daa 1675NAME: proxy_protocol_access
3d674977 1676TYPE: acl_access
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AJ
1677LOC: Config.accessList.proxyProtocol
1678DEFAULT: none
c390580b 1679DEFAULT_DOC: all TCP connections to ports with require-proxy-header will be denied
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1680DOC_START
1681 Determine which client proxies can be trusted to provide correct
1682 information regarding real client IP address using PROXY protocol.
1683
1684 Requests may pass through a chain of several other proxies
1685 before reaching us. The original source details may by sent in:
1686 * HTTP message Forwarded header, or
1687 * HTTP message X-Forwarded-For header, or
1688 * PROXY protocol connection header.
1689
1690 This directive is solely for validating new PROXY protocol
1691 connections received from a port flagged with require-proxy-header.
1692 It is checked only once after TCP connection setup.
1693
1694 A deny match results in TCP connection closure.
1695
1696 An allow match is required for Squid to permit the corresponding
1697 TCP connection, before Squid even looks for HTTP request headers.
1698 If there is an allow match, Squid starts using PROXY header information
1699 to determine the source address of the connection for all future ACL
1700 checks, logging, etc.
1701
1702 SECURITY CONSIDERATIONS:
1703
c390580b 1704 Any host from which we accept client IP details can place
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AJ
1705 incorrect information in the relevant header, and Squid
1706 will use the incorrect information as if it were the
1707 source address of the request. This may enable remote
1708 hosts to bypass any access control restrictions that are
1709 based on the client's source addresses.
1710
1711 This clause only supports fast acl types.
1712 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1713DOC_END
1714
1715NAME: follow_x_forwarded_for
1716TYPE: acl_access
1717IFDEF: FOLLOW_X_FORWARDED_FOR
3d674977 1718LOC: Config.accessList.followXFF
3d674977 1719DEFAULT_IF_NONE: deny all
9353df52 1720DEFAULT_DOC: X-Forwarded-For header will be ignored.
3d674977 1721DOC_START
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1722 Determine which client proxies can be trusted to provide correct
1723 information regarding real client IP address.
1724
3d674977 1725 Requests may pass through a chain of several other proxies
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1726 before reaching us. The original source details may by sent in:
1727 * HTTP message Forwarded header, or
1728 * HTTP message X-Forwarded-For header, or
1729 * PROXY protocol connection header.
3d674977 1730
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AJ
1731 PROXY protocol connections are controlled by the proxy_protocol_access
1732 directive which is checked before this.
1733
3d674977 1734 If a request reaches us from a source that is allowed by this
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AJ
1735 directive, then we trust the information it provides regarding
1736 the IP of the client it received from (if any).
1737
1738 For the purpose of ACLs used in this directive the src ACL type always
1739 matches the address we are testing and srcdomain matches its rDNS.
1740
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1741 On each HTTP request Squid checks for X-Forwarded-For header fields.
1742 If found the header values are iterated in reverse order and an allow
1743 match is required for Squid to continue on to the next value.
1744 The verification ends when a value receives a deny match, cannot be
1745 tested, or there are no more values to test.
1746 NOTE: Squid does not yet follow the Forwarded HTTP header.
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AJ
1747
1748 The end result of this process is an IP address that we will
1749 refer to as the indirect client address. This address may
57d76dd4 1750 be treated as the client address for access control, ICAP, delay
3d674977 1751 pools and logging, depending on the acl_uses_indirect_client,
9603207d 1752 icap_uses_indirect_client, delay_pool_uses_indirect_client,
96d64448 1753 log_uses_indirect_client and tproxy_uses_indirect_client options.
3d674977 1754
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1755 This clause only supports fast acl types.
1756 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1757
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1758 SECURITY CONSIDERATIONS:
1759
c390580b 1760 Any host from which we accept client IP details can place
70a16fea 1761 incorrect information in the relevant header, and Squid
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1762 will use the incorrect information as if it were the
1763 source address of the request. This may enable remote
1764 hosts to bypass any access control restrictions that are
1765 based on the client's source addresses.
1766
1767 For example:
1768
1769 acl localhost src 127.0.0.1
1770 acl my_other_proxy srcdomain .proxy.example.com
1771 follow_x_forwarded_for allow localhost
1772 follow_x_forwarded_for allow my_other_proxy
1773DOC_END
1774
1775NAME: acl_uses_indirect_client
1776COMMENT: on|off
1777TYPE: onoff
1778IFDEF: FOLLOW_X_FORWARDED_FOR
1779DEFAULT: on
1780LOC: Config.onoff.acl_uses_indirect_client
1781DOC_START
1782 Controls whether the indirect client address
1783 (see follow_x_forwarded_for) is used instead of the
1784 direct client address in acl matching.
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1785
1786 NOTE: maxconn ACL considers direct TCP links and indirect
1787 clients will always have zero. So no match.
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1788DOC_END
1789
1790NAME: delay_pool_uses_indirect_client
1791COMMENT: on|off
1792TYPE: onoff
9a0a18de 1793IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
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1794DEFAULT: on
1795LOC: Config.onoff.delay_pool_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 in delay pools.
1800DOC_END
1801
1802NAME: log_uses_indirect_client
1803COMMENT: on|off
1804TYPE: onoff
1805IFDEF: FOLLOW_X_FORWARDED_FOR
1806DEFAULT: on
1807LOC: Config.onoff.log_uses_indirect_client
1808DOC_START
1809 Controls whether the indirect client address
1810 (see follow_x_forwarded_for) is used instead of the
1811 direct client address in the access log.
1812DOC_END
1813
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1814NAME: tproxy_uses_indirect_client
1815COMMENT: on|off
1816TYPE: onoff
1817IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
4d7ab5a2 1818DEFAULT: off
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1819LOC: Config.onoff.tproxy_uses_indirect_client
1820DOC_START
1821 Controls whether the indirect client address
1822 (see follow_x_forwarded_for) is used instead of the
1823 direct client address when spoofing the outgoing client.
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1824
1825 This has no effect on requests arriving in non-tproxy
1826 mode ports.
1827
1828 SECURITY WARNING: Usage of this option is dangerous
1829 and should not be used trivially. Correct configuration
16ae256c 1830 of follow_x_forwarded_for with a limited set of trusted
4d7ab5a2 1831 sources is required to prevent abuse of your proxy.
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1832DOC_END
1833
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1834NAME: spoof_client_ip
1835TYPE: acl_access
1836LOC: Config.accessList.spoof_client_ip
1837DEFAULT: none
1838DEFAULT_DOC: Allow spoofing on all TPROXY traffic.
1839DOC_START
1840 Control client IP address spoofing of TPROXY traffic based on
1841 defined access lists.
1842
1843 spoof_client_ip allow|deny [!]aclname ...
1844
1845 If there are no "spoof_client_ip" lines present, the default
1846 is to "allow" spoofing of any suitable request.
1847
1848 Note that the cache_peer "no-tproxy" option overrides this ACL.
1849
1850 This clause supports fast acl types.
1851 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1852DOC_END
1853
41bd17a4 1854NAME: http_access
1855TYPE: acl_access
1856LOC: Config.accessList.http
41bd17a4 1857DEFAULT_IF_NONE: deny all
638402dd 1858DEFAULT_DOC: Deny, unless rules exist in squid.conf.
41bd17a4 1859DOC_START
1860 Allowing or Denying access based on defined access lists
cccac0a2 1861
8a2f40dd 1862 To allow or deny a message received on an HTTP, HTTPS, or FTP port:
41bd17a4 1863 http_access allow|deny [!]aclname ...
cccac0a2 1864
41bd17a4 1865 NOTE on default values:
cccac0a2 1866
41bd17a4 1867 If there are no "access" lines present, the default is to deny
1868 the request.
cccac0a2 1869
41bd17a4 1870 If none of the "access" lines cause a match, the default is the
1871 opposite of the last line in the list. If the last line was
1872 deny, the default is allow. Conversely, if the last line
1873 is allow, the default will be deny. For these reasons, it is a
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1874 good idea to have an "deny all" entry at the end of your access
1875 lists to avoid potential confusion.
cccac0a2 1876
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1877 This clause supports both fast and slow acl types.
1878 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1879
47f0eaea 1880CONFIG_START
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1881
1882#
1883# Recommended minimum Access Permission configuration:
41bd17a4 1884#
e0855596 1885# Deny requests to certain unsafe ports
41bd17a4 1886http_access deny !Safe_ports
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1887
1888# Deny CONNECT to other than secure SSL ports
41bd17a4 1889http_access deny CONNECT !SSL_ports
e0855596 1890
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1891# Only allow cachemgr access from localhost
1892http_access allow localhost manager
1893http_access deny manager
1894
41bd17a4 1895# We strongly recommend the following be uncommented to protect innocent
1896# web applications running on the proxy server who think the only
1897# one who can access services on "localhost" is a local user
1898#http_access deny to_localhost
e0855596 1899
41bd17a4 1900#
1901# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
e0855596 1902#
c8f4eac4 1903
ee776778 1904# Example rule allowing access from your local networks.
1905# Adapt localnet in the ACL section to list your (internal) IP networks
1906# from where browsing should be allowed
1907http_access allow localnet
afb33856 1908http_access allow localhost
7d90757b 1909
41bd17a4 1910# And finally deny all other access to this proxy
1911http_access deny all
47f0eaea 1912CONFIG_END
41bd17a4 1913DOC_END
7d90757b 1914
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1915NAME: adapted_http_access http_access2
1916TYPE: acl_access
1917LOC: Config.accessList.adapted_http
1918DEFAULT: none
638402dd 1919DEFAULT_DOC: Allow, unless rules exist in squid.conf.
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1920DOC_START
1921 Allowing or Denying access based on defined access lists
1922
1923 Essentially identical to http_access, but runs after redirectors
1924 and ICAP/eCAP adaptation. Allowing access control based on their
1925 output.
1926
1927 If not set then only http_access is used.
1928DOC_END
1929
41bd17a4 1930NAME: http_reply_access
1931TYPE: acl_access
1932LOC: Config.accessList.reply
1933DEFAULT: none
638402dd 1934DEFAULT_DOC: Allow, unless rules exist in squid.conf.
41bd17a4 1935DOC_START
1936 Allow replies to client requests. This is complementary to http_access.
cccac0a2 1937
41bd17a4 1938 http_reply_access allow|deny [!] aclname ...
cccac0a2 1939
41bd17a4 1940 NOTE: if there are no access lines present, the default is to allow
638402dd 1941 all replies.
1a224843 1942
41bd17a4 1943 If none of the access lines cause a match the opposite of the
1944 last line will apply. Thus it is good practice to end the rules
1945 with an "allow all" or "deny all" entry.
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1946
1947 This clause supports both fast and slow acl types.
1948 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 1949DOC_END
1950
41bd17a4 1951NAME: icp_access
1952TYPE: acl_access
1953LOC: Config.accessList.icp
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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 ICP port based on defined
1958 access lists
5473c134 1959
41bd17a4 1960 icp_access allow|deny [!]aclname ...
5473c134 1961
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1962 NOTE: The default if no icp_access lines are present is to
1963 deny all traffic. This default may cause problems with peers
1964 using ICP.
41bd17a4 1965
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1966 This clause only supports fast acl types.
1967 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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1968
1969# Allow ICP queries from local networks only
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1970#icp_access allow localnet
1971#icp_access deny all
5473c134 1972DOC_END
1973
41bd17a4 1974NAME: htcp_access
1975IFDEF: USE_HTCP
1976TYPE: acl_access
1977LOC: Config.accessList.htcp
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1978DEFAULT: none
1979DEFAULT_DOC: Deny, unless rules exist in squid.conf.
5473c134 1980DOC_START
41bd17a4 1981 Allowing or Denying access to the HTCP port based on defined
1982 access lists
5473c134 1983
41bd17a4 1984 htcp_access allow|deny [!]aclname ...
5473c134 1985
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1986 See also htcp_clr_access for details on access control for
1987 cache purge (CLR) HTCP messages.
5473c134 1988
0b48417e 1989 NOTE: The default if no htcp_access lines are present is to
1990 deny all traffic. This default may cause problems with peers
18191440 1991 using the htcp option.
0b48417e 1992
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1993 This clause only supports fast acl types.
1994 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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1995
1996# Allow HTCP queries from local networks only
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1997#htcp_access allow localnet
1998#htcp_access deny all
41bd17a4 1999DOC_END
5473c134 2000
41bd17a4 2001NAME: htcp_clr_access
2002IFDEF: USE_HTCP
2003TYPE: acl_access
2004LOC: Config.accessList.htcp_clr
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2005DEFAULT: none
2006DEFAULT_DOC: Deny, unless rules exist in squid.conf.
41bd17a4 2007DOC_START
2008 Allowing or Denying access to purge content using HTCP based
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2009 on defined access lists.
2010 See htcp_access for details on general HTCP access control.
5473c134 2011
41bd17a4 2012 htcp_clr_access allow|deny [!]aclname ...
5473c134 2013
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2014 This clause only supports fast acl types.
2015 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
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2016
2017# Allow HTCP CLR requests from trusted peers
638402dd 2018acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
41bd17a4 2019htcp_clr_access allow htcp_clr_peer
638402dd 2020htcp_clr_access deny all
5473c134 2021DOC_END
2022
41bd17a4 2023NAME: miss_access
2024TYPE: acl_access
2025LOC: Config.accessList.miss
b8a25eaa 2026DEFAULT: none
638402dd 2027DEFAULT_DOC: Allow, unless rules exist in squid.conf.
5473c134 2028DOC_START
18d1eddf 2029 Determines whether network access is permitted when satisfying a request.
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2030
2031 For example;
2032 to force your neighbors to use you as a sibling instead of
2033 a parent.
5473c134 2034
638402dd 2035 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
41bd17a4 2036 miss_access deny !localclients
638402dd 2037 miss_access allow all
5473c134 2038
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2039 This means only your local clients are allowed to fetch relayed/MISS
2040 replies from the network and all other clients can only fetch cached
2041 objects (HITs).
2042
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2043 The default for this setting allows all clients who passed the
2044 http_access rules to relay via this proxy.
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FC
2045
2046 This clause only supports fast acl types.
2047 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2048DOC_END
2049
2050NAME: ident_lookup_access
2051TYPE: acl_access
2052IFDEF: USE_IDENT
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2053DEFAULT: none
2054DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
4daaf3cb 2055LOC: Ident::TheConfig.identLookup
5473c134 2056DOC_START
41bd17a4 2057 A list of ACL elements which, if matched, cause an ident
2058 (RFC 931) lookup to be performed for this request. For
2059 example, you might choose to always perform ident lookups
2060 for your main multi-user Unix boxes, but not for your Macs
2061 and PCs. By default, ident lookups are not performed for
2062 any requests.
5473c134 2063
41bd17a4 2064 To enable ident lookups for specific client addresses, you
2065 can follow this example:
5473c134 2066
4daaf3cb 2067 acl ident_aware_hosts src 198.168.1.0/24
41bd17a4 2068 ident_lookup_access allow ident_aware_hosts
2069 ident_lookup_access deny all
5473c134 2070
4daaf3cb 2071 Only src type ACL checks are fully supported. A srcdomain
41bd17a4 2072 ACL might work at times, but it will not always provide
2073 the correct result.
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FC
2074
2075 This clause only supports fast acl types.
2076 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2077DOC_END
5473c134 2078
5b0f5383 2079NAME: reply_body_max_size
2080COMMENT: size [acl acl...]
2081TYPE: acl_b_size_t
2082DEFAULT: none
638402dd 2083DEFAULT_DOC: No limit is applied.
5b0f5383 2084LOC: Config.ReplyBodySize
2085DOC_START
2086 This option specifies the maximum size of a reply body. It can be
2087 used to prevent users from downloading very large files, such as
2088 MP3's and movies. When the reply headers are received, the
2089 reply_body_max_size lines are processed, and the first line where
2090 all (if any) listed ACLs are true is used as the maximum body size
2091 for this reply.
2092
2093 This size is checked twice. First when we get the reply headers,
2094 we check the content-length value. If the content length value exists
2095 and is larger than the allowed size, the request is denied and the
2096 user receives an error message that says "the request or reply
2097 is too large." If there is no content-length, and the reply
2098 size exceeds this limit, the client's connection is just closed
2099 and they will receive a partial reply.
2100
2101 WARNING: downstream caches probably can not detect a partial reply
2102 if there is no content-length header, so they will cache
2103 partial responses and give them out as hits. You should NOT
2104 use this option if you have downstream caches.
2105
2106 WARNING: A maximum size smaller than the size of squid's error messages
2107 will cause an infinite loop and crash squid. Ensure that the smallest
2108 non-zero value you use is greater that the maximum header size plus
2109 the size of your largest error page.
2110
2111 If you set this parameter none (the default), there will be
2112 no limit imposed.
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2113
2114 Configuration Format is:
2115 reply_body_max_size SIZE UNITS [acl ...]
2116 ie.
2117 reply_body_max_size 10 MB
2118
5b0f5383 2119DOC_END
2120
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CT
2121NAME: on_unsupported_protocol
2122TYPE: on_unsupported_protocol
2123LOC: Config.accessList.on_unsupported_protocol
2124DEFAULT: none
2125DEFAULT_DOC: Respond with an error message to unidentifiable traffic
2126DOC_START
2127 Determines Squid behavior when encountering strange requests at the
56d089f3
CT
2128 beginning of an accepted TCP connection or the beginning of a bumped
2129 CONNECT tunnel. Controlling Squid reaction to unexpected traffic is
2130 especially useful in interception environments where Squid is likely
2131 to see connections for unsupported protocols that Squid should either
2132 terminate or tunnel at TCP level.
9603207d 2133
3248e962 2134 on_unsupported_protocol <action> [!]acl ...
9603207d 2135
56d089f3 2136 The first matching action wins. Only fast ACLs are supported.
3248e962
CT
2137
2138 Supported actions are:
9603207d 2139
3248e962
CT
2140 tunnel: Establish a TCP connection with the intended server and
2141 blindly shovel TCP packets between the client and server.
2142
2143 respond: Respond with an error message, using the transfer protocol
2144 for the Squid port that received the request (e.g., HTTP
2145 for connections intercepted at the http_port). This is the
2146 default.
56d089f3
CT
2147
2148 Squid expects the following traffic patterns:
2149
2150 http_port: a plain HTTP request
2151 https_port: SSL/TLS handshake followed by an [encrypted] HTTP request
2152 ftp_port: a plain FTP command (no on_unsupported_protocol support yet!)
2153 CONNECT tunnel on http_port: same as https_port
2154 CONNECT tunnel on https_port: same as https_port
2155
9155253a 2156 Currently, this directive has effect on intercepted connections and
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2157 bumped tunnels only. Other cases are not supported because Squid
2158 cannot know the intended destination of other traffic.
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2159
2160 For example:
2161 # define what Squid errors indicate receiving non-HTTP traffic:
2162 acl foreignProtocol squid_error ERR_PROTOCOL_UNKNOWN ERR_TOO_BIG
2163 # define what Squid errors indicate receiving nothing:
2164 acl serverTalksFirstProtocol squid_error ERR_REQUEST_START_TIMEOUT
2165 # tunnel everything that does not look like HTTP:
2166 on_unsupported_protocol tunnel foreignProtocol
2167 # tunnel if we think the client waits for the server to talk first:
2168 on_unsupported_protocol tunnel serverTalksFirstProtocol
2169 # in all other error cases, just send an HTTP "error page" response:
2170 on_unsupported_protocol respond all
2171
2172 See also: squid_error ACL
2173DOC_END
2174
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2175NAME: auth_schemes
2176TYPE: AuthSchemes
2177IFDEF: USE_AUTH
2178LOC: Auth::TheConfig.schemeAccess
2179DEFAULT: none
2180DEFAULT_DOC: use all auth_param schemes in their configuration order
2181DOC_START
2182 Use this directive to customize authentication schemes presence and
2183 order in Squid's Unauthorized and Authentication Required responses.
2184
2185 auth_schemes scheme1,scheme2,... [!]aclname ...
2186
2187 where schemeN is the name of one of the authentication schemes
2188 configured using auth_param directives. At least one scheme name is
2189 required. Multiple scheme names are separated by commas. Either
2190 avoid whitespace or quote the entire schemes list.
2191
2192 A special "ALL" scheme name expands to all auth_param-configured
2193 schemes in their configuration order. This directive cannot be used
2194 to configure Squid to offer no authentication schemes at all.
2195
2196 The first matching auth_schemes rule determines the schemes order
2197 for the current Authentication Required transaction. Note that the
2198 future response is not yet available during auth_schemes evaluation.
2199
2200 If this directive is not used or none of its rules match, then Squid
2201 responds with all configured authentication schemes in the order of
2202 auth_param directives in the configuration file.
2203
2204 This directive does not determine when authentication is used or
2205 how each authentication scheme authenticates clients.
2206
2207 The following example sends basic and negotiate authentication
2208 schemes, in that order, when requesting authentication of HTTP
2209 requests matching the isIE ACL (not shown) while sending all
2210 auth_param schemes in their configuration order to other clients:
2211
2212 auth_schemes basic,negotiate isIE
2213 auth_schemes ALL all # explicit default
2214
2215 This directive supports fast ACLs only.
2216
2217 See also: auth_param.
2218DOC_END
2219
5b0f5383 2220COMMENT_START
2221 NETWORK OPTIONS
2222 -----------------------------------------------------------------------------
2223COMMENT_END
2224
2225NAME: http_port ascii_port
65d448bc 2226TYPE: PortCfg
5b0f5383 2227DEFAULT: none
fa720bfb 2228LOC: HttpPortList
5b0f5383 2229DOC_START
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2230 Usage: port [mode] [options]
2231 hostname:port [mode] [options]
2232 1.2.3.4:port [mode] [options]
5b0f5383 2233
2234 The socket addresses where Squid will listen for HTTP client
2235 requests. You may specify multiple socket addresses.
2236 There are three forms: port alone, hostname with port, and
2237 IP address with port. If you specify a hostname or IP
2238 address, Squid binds the socket to that specific
c7b1dd5d 2239 address. Most likely, you do not need to bind to a specific
5b0f5383 2240 address, so you can use the port number alone.
2241
2242 If you are running Squid in accelerator mode, you
2243 probably want to listen on port 80 also, or instead.
2244
2245 The -a command line option may be used to specify additional
2246 port(s) where Squid listens for proxy request. Such ports will
2247 be plain proxy ports with no options.
2248
2249 You may specify multiple socket addresses on multiple lines.
2250
c7b1dd5d 2251 Modes:
5b0f5383 2252
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2253 intercept Support for IP-Layer NAT interception delivering
2254 traffic to this Squid port.
2255 NP: disables authentication on the port.
5b0f5383 2256
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2257 tproxy Support Linux TPROXY (or BSD divert-to) with spoofing
2258 of outgoing connections using the client IP address.
2259 NP: disables authentication on the port.
5b0f5383 2260
7f45065d 2261 accel Accelerator / reverse proxy mode
5b0f5383 2262
caf3666d 2263 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
c7b1dd5d 2264 establish secure connection with the client and with
caf3666d 2265 the server, decrypt HTTPS messages as they pass through
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2266 Squid, and treat them as unencrypted HTTP messages,
2267 becoming the man-in-the-middle.
2268
7a957a93 2269 The ssl_bump option is required to fully enable
caf3666d 2270 bumping of CONNECT requests.
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2271
2272 Omitting the mode flag causes default forward proxy mode to be used.
2273
2274
2275 Accelerator Mode Options:
2276
5b0f5383 2277 defaultsite=domainname
2278 What to use for the Host: header if it is not present
2279 in a request. Determines what site (not origin server)
2280 accelerators should consider the default.
5b0f5383 2281
cf673853 2282 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
5b0f5383 2283
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2284 protocol= Protocol to reconstruct accelerated and intercepted
2285 requests with. Defaults to HTTP/1.1 for http_port and
2286 HTTPS/1.1 for https_port.
2287 When an unsupported value is configured Squid will
2288 produce a FATAL error.
2289 Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
5b0f5383 2290
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2291 vport Virtual host port support. Using the http_port number
2292 instead of the port passed on Host: headers.
5b0f5383 2293
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2294 vport=NN Virtual host port support. Using the specified port
2295 number instead of the port passed on Host: headers.
5b0f5383 2296
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2297 act-as-origin
2298 Act as if this Squid is the origin server.
2299 This currently means generate new Date: and Expires:
2300 headers on HIT instead of adding Age:.
5b0f5383 2301
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2302 ignore-cc Ignore request Cache-Control headers.
2303
7f45065d 2304 WARNING: This option violates HTTP specifications if
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2305 used in non-accelerator setups.
2306
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2307 allow-direct Allow direct forwarding in accelerator mode. Normally
2308 accelerated requests are denied direct forwarding as if
2309 never_direct was used.
2310
2311 WARNING: this option opens accelerator mode to security
2312 vulnerabilities usually only affecting in interception
2313 mode. Make sure to protect forwarding with suitable
2314 http_access rules when using this.
2315
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2316
2317 SSL Bump Mode Options:
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2318 In addition to these options ssl-bump requires TLS/SSL options.
2319
2320 generate-host-certificates[=<on|off>]
2321 Dynamically create SSL server certificates for the
9603207d 2322 destination hosts of bumped CONNECT requests.When
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2323 enabled, the cert and key options are used to sign
2324 generated certificates. Otherwise generated
2325 certificate will be selfsigned.
9603207d 2326 If there is a CA certificate lifetime of the generated
859741ed 2327 certificate equals lifetime of the CA certificate. If
9603207d 2328 generated certificate is selfsigned lifetime is three
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2329 years.
2330 This option is enabled by default when ssl-bump is used.
2331 See the ssl-bump option above for more information.
9603207d 2332
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2333 dynamic_cert_mem_cache_size=SIZE
2334 Approximate total RAM size spent on cached generated
2335 certificates. If set to zero, caching is disabled. The
23bb0ebf 2336 default value is 4MB.
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2337
2338 TLS / SSL Options:
c7b1dd5d 2339
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2340 tls-cert= Path to file containing an X.509 certificate (PEM format)
2341 to be used in the TLS handshake ServerHello.
c7b1dd5d 2342
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2343 If this certificate is constrained by KeyUsage TLS
2344 feature it must allow HTTP server usage, along with
2345 any additional restrictions imposed by your choice
2346 of options= settings.
2347
2348 When OpenSSL is used this file may also contain a
2349 chain of intermediate CA certificates to send in the
2350 TLS handshake.
2351
2352 When GnuTLS is used this option (and any paired
2353 tls-key= option) may be repeated to load multiple
2354 certificates for different domains.
2355
2356 Also, when generate-host-certificates=on is configured
2357 the first tls-cert= option must be a CA certificate
2358 capable of signing the automatically generated
2359 certificates.
2360
2361 tls-key= Path to a file containing private key file (PEM format)
2362 for the previous tls-cert= option.
2363
2364 If tls-key= is not specified tls-cert= is assumed to
2365 reference a PEM file containing both the certificate
2366 and private key.
c7b1dd5d 2367
c7b1dd5d 2368 cipher= Colon separated list of supported ciphers.
bebdc6fb
AJ
2369 NOTE: some ciphers such as EDH ciphers depend on
2370 additional settings. If those settings are
2371 omitted the ciphers may be silently ignored
2372 by the OpenSSL library.
c7b1dd5d 2373
943c5f16 2374 options= Various SSL implementation options. The most important
c7b1dd5d 2375 being:
7905e7be 2376
3d96b0e8 2377 NO_SSLv3 Disallow the use of SSLv3
1f1f29e8 2378
3d96b0e8 2379 NO_TLSv1 Disallow the use of TLSv1.0
1f1f29e8 2380
3d96b0e8 2381 NO_TLSv1_1 Disallow the use of TLSv1.1
1f1f29e8 2382
3d96b0e8 2383 NO_TLSv1_2 Disallow the use of TLSv1.2
1f1f29e8 2384
7905e7be
AJ
2385 SINGLE_DH_USE
2386 Always create a new key when using
c7b1dd5d 2387 temporary/ephemeral DH key exchanges
1f1f29e8 2388
54fbe371
PM
2389 SINGLE_ECDH_USE
2390 Enable ephemeral ECDH key exchange.
2391 The adopted curve should be specified
2392 using the tls-dh option.
2393
36092741 2394 NO_TICKET
1f1f29e8
AJ
2395 Disable use of RFC5077 session tickets.
2396 Some servers may have problems
2397 understanding the TLS extension due
2398 to ambiguous specification in RFC4507.
2399
943c5f16
HN
2400 ALL Enable various bug workarounds
2401 suggested as "harmless" by OpenSSL
2402 Be warned that this reduces SSL/TLS
2403 strength to some attacks.
7905e7be
AJ
2404
2405 See the OpenSSL SSL_CTX_set_options documentation for a
2406 more complete list.
c7b1dd5d
AJ
2407
2408 clientca= File containing the list of CAs to use when
2409 requesting a client certificate.
2410
86a84cc0
AJ
2411 tls-cafile= PEM file containing CA certificates to use when verifying
2412 client certificates. If not configured clientca will be
2413 used. May be repeated to load multiple files.
c7b1dd5d
AJ
2414
2415 capath= Directory containing additional CA certificates
2416 and CRL lists to use when verifying client certificates.
86a84cc0 2417 Requires OpenSSL or LibreSSL.
c7b1dd5d
AJ
2418
2419 crlfile= File of additional CRL lists to use when verifying
2420 the client certificate, in addition to CRLs stored in
2421 the capath. Implies VERIFY_CRL flag below.
2422
54fbe371
PM
2423 tls-dh=[curve:]file
2424 File containing DH parameters for temporary/ephemeral DH key
2425 exchanges, optionally prefixed by a curve for ephemeral ECDH
2426 key exchanges.
2427 See OpenSSL documentation for details on how to create the
2428 DH parameter file. Supported curves for ECDH can be listed
2429 using the "openssl ecparam -list_curves" command.
2430 WARNING: EDH and EECDH ciphers will be silently disabled if
2431 this option is not set.
c7b1dd5d
AJ
2432
2433 sslflags= Various flags modifying the use of SSL:
2434 DELAYED_AUTH
2435 Don't request client certificates
2436 immediately, but wait until acl processing
2437 requires a certificate (not yet implemented).
983fab6e 2438 CONDITIONAL_AUTH
2439 Request a client certificate during the TLS
2440 handshake, but ignore certificate absence in
2441 the TLS client Hello. If the client does
2442 supply a certificate, it is validated.
c7b1dd5d
AJ
2443 NO_SESSION_REUSE
2444 Don't allow for session reuse. Each connection
2445 will result in a new SSL session.
2446 VERIFY_CRL
2447 Verify CRL lists when accepting client
2448 certificates.
2449 VERIFY_CRL_ALL
2450 Verify CRL lists for all certificates in the
2451 client certificate chain.
2452
435c72b0
AJ
2453 tls-default-ca[=off]
2454 Whether to use the system Trusted CAs. Default is OFF.
8b253b83 2455
b05d749d
AJ
2456 tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
2457
c7b1dd5d
AJ
2458 sslcontext= SSL session ID context identifier.
2459
c7b1dd5d
AJ
2460 Other Options:
2461
6b185b50 2462 connection-auth[=on|off]
9603207d 2463 use connection-auth=off to tell Squid to prevent
6b185b50 2464 forwarding Microsoft connection oriented authentication
d67acb4e
AJ
2465 (NTLM, Negotiate and Kerberos)
2466
5b0f5383 2467 disable-pmtu-discovery=
2468 Control Path-MTU discovery usage:
2469 off lets OS decide on what to do (default).
2470 transparent disable PMTU discovery when transparent
2471 support is enabled.
2472 always disable always PMTU discovery.
2473
2474 In many setups of transparently intercepting proxies
2475 Path-MTU discovery can not work on traffic towards the
2476 clients. This is the case when the intercepting device
2477 does not fully track connections and fails to forward
2478 ICMP must fragment messages to the cache server. If you
2479 have such setup and experience that certain clients
2480 sporadically hang or never complete requests set
2481 disable-pmtu-discovery option to 'transparent'.
2482
81b6e9a7 2483 name= Specifies a internal name for the port. Defaults to
2484 the port specification (port or addr:port)
2485
68924b6d 2486 tcpkeepalive[=idle,interval,timeout]
fb6c6dbe
AJ
2487 Enable TCP keepalive probes of idle connections.
2488 In seconds; idle is the initial time before TCP starts
2489 probing the connection, interval how often to probe, and
b2130d58 2490 timeout the time before giving up.
2491
d3d92daa 2492 require-proxy-header
151ba0d4 2493 Require PROXY protocol version 1 or 2 connections.
70d0ef18 2494 The proxy_protocol_access is required to permit
151ba0d4
AJ
2495 downstream proxies which can be trusted.
2496
7d17a6a6
EB
2497 worker-queues
2498 Ask TCP stack to maintain a dedicated listening queue
2499 for each worker accepting requests at this port.
2500 Requires TCP stack that supports the SO_REUSEPORT socket
2501 option.
2502
2503 SECURITY WARNING: Enabling worker-specific queues
2504 allows any process running as Squid's effective user to
2505 easily accept requests destined to this port.
2506
5b0f5383 2507 If you run Squid on a dual-homed machine with an internal
2508 and an external interface we recommend you to specify the
2509 internal address:port in http_port. This way Squid will only be
2510 visible on the internal address.
2511
47f0eaea 2512CONFIG_START
e0855596 2513
5b0f5383 2514# Squid normally listens to port 3128
2515http_port @DEFAULT_HTTP_PORT@
47f0eaea 2516CONFIG_END
5b0f5383 2517DOC_END
2518
2519NAME: https_port
339e4d7a 2520IFDEF: USE_GNUTLS||USE_OPENSSL
65d448bc 2521TYPE: PortCfg
5b0f5383 2522DEFAULT: none
339e4d7a 2523LOC: HttpPortList
5b0f5383 2524DOC_START
51e09c08 2525 Usage: [ip:]port [mode] tls-cert=certificate.pem [options]
5b0f5383 2526
859741ed
AJ
2527 The socket address where Squid will listen for client requests made
2528 over TLS or SSL connections. Commonly referred to as HTTPS.
5b0f5383 2529
859741ed 2530 This is most useful for situations where you are running squid in
51e09c08
AJ
2531 accelerator mode and you want to do the TLS work at the accelerator
2532 level.
5b0f5383 2533
2534 You may specify multiple socket addresses on multiple lines,
9155253a 2535 each with their own certificate and/or options.
5b0f5383 2536
51e09c08 2537 The tls-cert= option is mandatory on HTTPS ports.
379e8c1c 2538
9155253a 2539 See http_port for a list of modes and options.
5b0f5383 2540DOC_END
2541
434a79b0
DK
2542NAME: ftp_port
2543TYPE: PortCfg
2544DEFAULT: none
8ea0d847 2545LOC: FtpPortList
434a79b0 2546DOC_START
8a2f40dd
AR
2547 Enables Native FTP proxy by specifying the socket address where Squid
2548 listens for FTP client requests. See http_port directive for various
2549 ways to specify the listening address and mode.
2550
2551 Usage: ftp_port address [mode] [options]
2552
2553 WARNING: This is a new, experimental, complex feature that has seen
2554 limited production exposure. Some Squid modules (e.g., caching) do not
2555 currently work with native FTP proxying, and many features have not
2556 even been tested for compatibility. Test well before deploying!
2557
2558 Native FTP proxying differs substantially from proxying HTTP requests
2559 with ftp:// URIs because Squid works as an FTP server and receives
2560 actual FTP commands (rather than HTTP requests with FTP URLs).
2561
2562 Native FTP commands accepted at ftp_port are internally converted or
2563 wrapped into HTTP-like messages. The same happens to Native FTP
2564 responses received from FTP origin servers. Those HTTP-like messages
2565 are shoveled through regular access control and adaptation layers
2566 between the FTP client and the FTP origin server. This allows Squid to
2567 examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
2568 mechanisms when shoveling wrapped FTP messages. For example,
2569 http_access and adaptation_access directives are used.
2570
2571 Modes:
2572
3cc0f4e7 2573 intercept Same as http_port intercept. The FTP origin address is
8a2f40dd
AR
2574 determined based on the intended destination of the
2575 intercepted connection.
2576
3cc0f4e7
AR
2577 tproxy Support Linux TPROXY for spoofing outgoing
2578 connections using the client IP address.
2579 NP: disables authentication and maybe IPv6 on the port.
2580
8a2f40dd
AR
2581 By default (i.e., without an explicit mode option), Squid extracts the
2582 FTP origin address from the login@origin parameter of the FTP USER
2583 command. Many popular FTP clients support such native FTP proxying.
2584
2585 Options:
2586
3cc0f4e7
AR
2587 name=token Specifies an internal name for the port. Defaults to
2588 the port address. Usable with myportname ACL.
2589
aea65fec 2590 ftp-track-dirs
8a2f40dd
AR
2591 Enables tracking of FTP directories by injecting extra
2592 PWD commands and adjusting Request-URI (in wrapping
2593 HTTP requests) to reflect the current FTP server
aea65fec 2594 directory. Tracking is disabled by default.
8a2f40dd 2595
3cc0f4e7
AR
2596 protocol=FTP Protocol to reconstruct accelerated and intercepted
2597 requests with. Defaults to FTP. No other accepted
2598 values have been tested with. An unsupported value
2599 results in a FATAL error. Accepted values are FTP,
2600 HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
2601
8a2f40dd
AR
2602 Other http_port modes and options that are not specific to HTTP and
2603 HTTPS may also work.
2604DOC_END
434a79b0 2605
41bd17a4 2606NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2607TYPE: acl_tos
5473c134 2608DEFAULT: none
425de4c8 2609LOC: Ip::Qos::TheConfig.tosToServer
5473c134 2610DOC_START
425de4c8
AJ
2611 Allows you to select a TOS/Diffserv value for packets outgoing
2612 on the server side, based on an ACL.
5473c134 2613
41bd17a4 2614 tcp_outgoing_tos ds-field [!]aclname ...
cccac0a2 2615
41bd17a4 2616 Example where normal_service_net uses the TOS value 0x00
7def7206 2617 and good_service_net uses 0x20
cccac0a2 2618
864a62b5
AJ
2619 acl normal_service_net src 10.0.0.0/24
2620 acl good_service_net src 10.0.1.0/24
2c73de90 2621 tcp_outgoing_tos 0x00 normal_service_net
41bd17a4 2622 tcp_outgoing_tos 0x20 good_service_net
fa38076e 2623
41bd17a4 2624 TOS/DSCP values really only have local significance - so you should
575cb927
AJ
2625 know what you're specifying. For more information, see RFC2474,
2626 RFC2475, and RFC3260.
cccac0a2 2627
41bd17a4 2628 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
5f53baab
SM
2629 "default" to use whatever default your host has.
2630 Note that only multiples of 4 are usable as the two rightmost bits have
2631 been redefined for use by ECN (RFC 3168 section 23.1).
2632 The squid parser will enforce this by masking away the ECN bits.
cccac0a2 2633
41bd17a4 2634 Processing proceeds in the order specified, and stops at first fully
2635 matching line.
c6f168c1
CT
2636
2637 Only fast ACLs are supported.
cccac0a2 2638DOC_END
2639
41bd17a4 2640NAME: clientside_tos
2641TYPE: acl_tos
cccac0a2 2642DEFAULT: none
425de4c8
AJ
2643LOC: Ip::Qos::TheConfig.tosToClient
2644DOC_START
5f53baab 2645 Allows you to select a TOS/DSCP value for packets being transmitted
425de4c8
AJ
2646 on the client-side, based on an ACL.
2647
2648 clientside_tos ds-field [!]aclname ...
2649
2650 Example where normal_service_net uses the TOS value 0x00
2651 and good_service_net uses 0x20
2652
2653 acl normal_service_net src 10.0.0.0/24
2654 acl good_service_net src 10.0.1.0/24
2655 clientside_tos 0x00 normal_service_net
2656 clientside_tos 0x20 good_service_net
2657
2658 Note: This feature is incompatible with qos_flows. Any TOS values set here
2659 will be overwritten by TOS values in qos_flows.
5f53baab
SM
2660
2661 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2662 "default" to use whatever default your host has.
2663 Note that only multiples of 4 are usable as the two rightmost bits have
2664 been redefined for use by ECN (RFC 3168 section 23.1).
2665 The squid parser will enforce this by masking away the ECN bits.
2666
83a846a3
AR
2667 This clause only supports fast acl types.
2668 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
425de4c8
AJ
2669DOC_END
2670
2671NAME: tcp_outgoing_mark
2672TYPE: acl_nfmark
11e8cfe3 2673IFDEF: SO_MARK&&USE_LIBCAP
425de4c8
AJ
2674DEFAULT: none
2675LOC: Ip::Qos::TheConfig.nfmarkToServer
2676DOC_START
2677 Allows you to apply a Netfilter mark value to outgoing packets
2678 on the server side, based on an ACL.
2679
2680 tcp_outgoing_mark mark-value [!]aclname ...
2681
2682 Example where normal_service_net uses the mark value 0x00
2683 and good_service_net uses 0x20
2684
2685 acl normal_service_net src 10.0.0.0/24
2686 acl good_service_net src 10.0.1.0/24
2687 tcp_outgoing_mark 0x00 normal_service_net
2688 tcp_outgoing_mark 0x20 good_service_net
c6f168c1
CT
2689
2690 Only fast ACLs are supported.
425de4c8
AJ
2691DOC_END
2692
244da4ad 2693NAME: mark_client_packet clientside_mark
425de4c8 2694TYPE: acl_nfmark
11e8cfe3 2695IFDEF: SO_MARK&&USE_LIBCAP
425de4c8
AJ
2696DEFAULT: none
2697LOC: Ip::Qos::TheConfig.nfmarkToClient
cccac0a2 2698DOC_START
244da4ad 2699 Allows you to apply a Netfilter MARK value to packets being transmitted
425de4c8
AJ
2700 on the client-side, based on an ACL.
2701
244da4ad 2702 mark_client_packet mark-value [!]aclname ...
425de4c8 2703
244da4ad 2704 Example where normal_service_net uses the MARK value 0x00
425de4c8
AJ
2705 and good_service_net uses 0x20
2706
2707 acl normal_service_net src 10.0.0.0/24
2708 acl good_service_net src 10.0.1.0/24
244da4ad
AG
2709 mark_client_packet 0x00 normal_service_net
2710 mark_client_packet 0x20 good_service_net
425de4c8
AJ
2711
2712 Note: This feature is incompatible with qos_flows. Any mark values set here
2713 will be overwritten by mark values in qos_flows.
83a846a3
AR
2714
2715 This clause only supports fast acl types.
2716 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 2717DOC_END
cccac0a2 2718
244da4ad
AG
2719NAME: mark_client_connection
2720TYPE: acl_nfmark
2721IFDEF: SO_MARK&&USE_LIBCAP
2722DEFAULT: none
2723LOC: Ip::Qos::TheConfig.nfConnmarkToClient
2724DOC_START
2725 Allows you to apply a Netfilter CONNMARK value to a connection
2726 on the client-side, based on an ACL.
2727
2728 mark_client_connection mark-value[/mask] [!]aclname ...
2729
2730 The mark-value and mask are unsigned integers (hex, octal, or decimal).
2731 The mask may be used to preserve marking previously set by other agents
2732 (e.g., iptables).
2733
2734 A matching rule replaces the CONNMARK value. If a mask is also
2735 specified, then the masked bits of the original value are zeroed, and
2736 the configured mark-value is ORed with that adjusted value.
2737 For example, applying a mark-value 0xAB/0xF to 0x5F CONNMARK, results
2738 in a 0xFB marking (rather than a 0xAB or 0x5B).
2739
2740 This directive semantics is similar to iptables --set-mark rather than
2741 --set-xmark functionality.
2742
2743 The directive does not interfere with qos_flows (which uses packet MARKs,
2744 not CONNMARKs).
2745
2746 Example where squid marks intercepted FTP connections:
2747
2748 acl proto_ftp proto FTP
2749 mark_client_connection 0x200/0xff00 proto_ftp
2750
2751 This clause only supports fast acl types.
2752 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2753DOC_END
2754
575cb927
AJ
2755NAME: qos_flows
2756TYPE: QosConfig
425de4c8 2757IFDEF: USE_QOS_TOS
575cb927 2758DEFAULT: none
b7ac5457 2759LOC: Ip::Qos::TheConfig
7172612f 2760DOC_START
575cb927 2761 Allows you to select a TOS/DSCP value to mark outgoing
196a7776
AB
2762 connections to the client, based on where the reply was sourced.
2763 For platforms using netfilter, allows you to set a netfilter mark
425de4c8 2764 value instead of, or in addition to, a TOS value.
7172612f 2765
196a7776
AB
2766 By default this functionality is disabled. To enable it with the default
2767 settings simply use "qos_flows mark" or "qos_flows tos". Default
2768 settings will result in the netfilter mark or TOS value being copied
2769 from the upstream connection to the client. Note that it is the connection
2770 CONNMARK value not the packet MARK value that is copied.
2771
2772 It is not currently possible to copy the mark or TOS value from the
2773 client to the upstream connection request.
2774
575cb927
AJ
2775 TOS values really only have local significance - so you should
2776 know what you're specifying. For more information, see RFC2474,
2777 RFC2475, and RFC3260.
7172612f 2778
5f53baab
SM
2779 The TOS/DSCP byte must be exactly that - a octet value 0 - 255.
2780 Note that only multiples of 4 are usable as the two rightmost bits have
2781 been redefined for use by ECN (RFC 3168 section 23.1).
2782 The squid parser will enforce this by masking away the ECN bits.
425de4c8
AJ
2783
2784 Mark values can be any unsigned 32-bit integer value.
7172612f 2785
425de4c8
AJ
2786 This setting is configured by setting the following values:
2787
2788 tos|mark Whether to set TOS or netfilter mark values
575cb927
AJ
2789
2790 local-hit=0xFF Value to mark local cache hits.
2791
2792 sibling-hit=0xFF Value to mark hits from sibling peers.
2793
2794 parent-hit=0xFF Value to mark hits from parent peers.
2795
a29d2a95
AB
2796 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2797 over the preserve-miss feature (see below), unless
2798 mask is specified, in which case only the bits
2799 specified in the mask are written.
575cb927 2800
425de4c8
AJ
2801 The TOS variant of the following features are only possible on Linux
2802 and require your kernel to be patched with the TOS preserving ZPH
2803 patch, available from http://zph.bratcheda.org
2804 No patch is needed to preserve the netfilter mark, which will work
2805 with all variants of netfilter.
575cb927 2806
575cb927 2807 disable-preserve-miss
425de4c8
AJ
2808 This option disables the preservation of the TOS or netfilter
2809 mark. By default, the existing TOS or netfilter mark value of
2810 the response coming from the remote server will be retained
2811 and masked with miss-mark.
2812 NOTE: in the case of a netfilter mark, the mark must be set on
2813 the connection (using the CONNMARK target) not on the packet
2814 (MARK target).
575cb927
AJ
2815
2816 miss-mask=0xFF
425de4c8
AJ
2817 Allows you to mask certain bits in the TOS or mark value
2818 received from the remote server, before copying the value to
2819 the TOS sent towards clients.
2820 Default for tos: 0xFF (TOS from server is not changed).
2821 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2822
2823 All of these features require the --enable-zph-qos compilation flag
2824 (enabled by default). Netfilter marking also requires the
2825 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2826 libcap 2.09+ (--with-libcap).
7172612f 2827
7172612f
AJ
2828DOC_END
2829
41bd17a4 2830NAME: tcp_outgoing_address
2831TYPE: acl_address
2832DEFAULT: none
638402dd 2833DEFAULT_DOC: Address selection is performed by the operating system.
41bd17a4 2834LOC: Config.accessList.outgoing_address
2835DOC_START
2836 Allows you to map requests to different outgoing IP addresses
2837 based on the username or source address of the user making
2838 the request.
7f7db318 2839
41bd17a4 2840 tcp_outgoing_address ipaddr [[!]aclname] ...
c33aa074 2841
2dd51400
AJ
2842 For example;
2843 Forwarding clients with dedicated IPs for certain subnets.
9197cd13 2844
2dd51400
AJ
2845 acl normal_service_net src 10.0.0.0/24
2846 acl good_service_net src 10.0.2.0/24
2847
2848 tcp_outgoing_address 2001:db8::c001 good_service_net
2849 tcp_outgoing_address 10.1.0.2 good_service_net
2850
2851 tcp_outgoing_address 2001:db8::beef normal_service_net
2852 tcp_outgoing_address 10.1.0.1 normal_service_net
2853
2854 tcp_outgoing_address 2001:db8::1
2855 tcp_outgoing_address 10.1.0.3
9197cd13 2856
41bd17a4 2857 Processing proceeds in the order specified, and stops at first fully
2858 matching line.
cccac0a2 2859
2dd51400
AJ
2860 Squid will add an implicit IP version test to each line.
2861 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2862 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2863
2864
2865 NOTE: The use of this directive using client dependent ACLs is
41bd17a4 2866 incompatible with the use of server side persistent connections. To
2867 ensure correct results it is best to set server_persistent_connections
2868 to off when using this directive in such configurations.
cc192b50 2869
2dd51400 2870 NOTE: The use of this directive to set a local IP on outgoing TCP links
4ed968be 2871 is incompatible with using TPROXY to set client IP out outbound TCP links.
2dd51400
AJ
2872 When needing to contact peers use the no-tproxy cache_peer option and the
2873 client_dst_passthru directive re-enable normal forwarding such as this.
cc192b50 2874
83a846a3
AR
2875 This clause only supports fast acl types.
2876 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 2877DOC_END
6db78a1a 2878
90529125
AJ
2879NAME: host_verify_strict
2880TYPE: onoff
2881DEFAULT: off
2882LOC: Config.onoff.hostStrictVerify
2883DOC_START
d8821934
AR
2884 Regardless of this option setting, when dealing with intercepted
2885 traffic, Squid always verifies that the destination IP address matches
2962f8b8 2886 the Host header domain or IP (called 'authority form URL').
9603207d 2887
d8821934
AR
2888 This enforcement is performed to satisfy a MUST-level requirement in
2889 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2890 authority of the origin server or gateway given by the original URL".
9603207d 2891
2962f8b8
AJ
2892 When set to ON:
2893 Squid always responds with an HTTP 409 (Conflict) error
2894 page and logs a security warning if there is no match.
9603207d 2895
2962f8b8
AJ
2896 Squid verifies that the destination IP address matches
2897 the Host header for forward-proxy and reverse-proxy traffic
2898 as well. For those traffic types, Squid also enables the
2899 following checks, comparing the corresponding Host header
2900 and Request-URI components:
9603207d 2901
2962f8b8
AJ
2902 * The host names (domain or IP) must be identical,
2903 but valueless or missing Host header disables all checks.
2904 For the two host names to match, both must be either IP
2905 or FQDN.
9603207d 2906
2962f8b8
AJ
2907 * Port numbers must be identical, but if a port is missing
2908 the scheme-default port is assumed.
9603207d 2909
2910
2962f8b8
AJ
2911 When set to OFF (the default):
2912 Squid allows suspicious requests to continue but logs a
2913 security warning and blocks caching of the response.
9603207d 2914
2962f8b8 2915 * Forward-proxy traffic is not checked at all.
9603207d 2916
2962f8b8 2917 * Reverse-proxy traffic is not checked at all.
9603207d 2918
2962f8b8 2919 * Intercepted traffic which passes verification is handled
32c32865 2920 according to client_dst_passthru.
9603207d 2921
7177edfb
AJ
2922 * Intercepted requests which fail verification are sent
2923 to the client original destination instead of DIRECT.
2924 This overrides 'client_dst_passthru off'.
9603207d 2925
2962f8b8
AJ
2926 For now suspicious intercepted CONNECT requests are always
2927 responded to with an HTTP 409 (Conflict) error page.
9603207d 2928
2929
7177edfb 2930 SECURITY NOTE:
9603207d 2931
bfe4e2fe
AJ
2932 As described in CVE-2009-0801 when the Host: header alone is used
2933 to determine the destination of a request it becomes trivial for
2934 malicious scripts on remote websites to bypass browser same-origin
2935 security policy and sandboxing protections.
9603207d 2936
bfe4e2fe
AJ
2937 The cause of this is that such applets are allowed to perform their
2938 own HTTP stack, in which case the same-origin policy of the browser
2939 sandbox only verifies that the applet tries to contact the same IP
2940 as from where it was loaded at the IP level. The Host: header may
2941 be different from the connected IP and approved origin.
9603207d 2942
7177edfb 2943DOC_END
6b185b50 2944
7177edfb
AJ
2945NAME: client_dst_passthru
2946TYPE: onoff
2947DEFAULT: on
2948LOC: Config.onoff.client_dst_passthru
2949DOC_START
2950 With NAT or TPROXY intercepted traffic Squid may pass the request
2951 directly to the original client destination IP or seek a faster
2952 source using the HTTP Host header.
9603207d 2953
7177edfb
AJ
2954 Using Host to locate alternative servers can provide faster
2955 connectivity with a range of failure recovery options.
2956 But can also lead to connectivity trouble when the client and
2957 server are attempting stateful interactions unaware of the proxy.
9603207d 2958
7177edfb
AJ
2959 This option (on by default) prevents alternative DNS entries being
2960 located to send intercepted traffic DIRECT to an origin server.
2961 The clients original destination IP and port will be used instead.
9603207d 2962
7177edfb
AJ
2963 Regardless of this option setting, when dealing with intercepted
2964 traffic Squid will verify the Host: header and any traffic which
2965 fails Host verification will be treated as if this option were ON.
9603207d 2966
7177edfb 2967 see host_verify_strict for details on the verification process.
cccac0a2 2968DOC_END
2969
195f8adb
AJ
2970COMMENT_START
2971 TLS OPTIONS
2972 -----------------------------------------------------------------------------
2973COMMENT_END
2974
2975NAME: tls_outgoing_options
2976IFDEF: USE_GNUTLS||USE_OPENSSL
2977TYPE: securePeerOptions
2fbb02b1 2978DEFAULT: min-version=1.0
7e62a74f 2979LOC: Security::ProxyOutgoingConfig
195f8adb
AJ
2980DOC_START
2981 disable Do not support https:// URLs.
9603207d 2982
195f8adb 2983 cert=/path/to/client/certificate
51e09c08 2984 A client X.509 certificate to use when connecting.
9603207d 2985
195f8adb 2986 key=/path/to/client/private_key
51e09c08
AJ
2987 The private key corresponding to the cert= above.
2988
2989 If key= is not specified cert= is assumed to
2990 reference a PEM file containing both the certificate
2991 and private key.
9603207d 2992
195f8adb 2993 cipher=... The list of valid TLS ciphers to use.
1cc44095
AJ
2994
2995 min-version=1.N
2fbb02b1
AJ
2996 The minimum TLS protocol version to permit.
2997 To control SSLv3 use the options= parameter.
d39e23a0 2998 Supported Values: 1.0 (default), 1.1, 1.2, 1.3
1cc44095 2999
3f5b28fe 3000 options=... Specify various TLS/SSL implementation options.
195f8adb 3001
3f5b28fe 3002 OpenSSL options most important are:
7905e7be 3003
3f5b28fe 3004 NO_SSLv3 Disallow the use of SSLv3
7905e7be 3005
195f8adb
AJ
3006 SINGLE_DH_USE
3007 Always create a new key when using
3008 temporary/ephemeral DH key exchanges
7905e7be 3009
ce0adf1a 3010 NO_TICKET
7905e7be
AJ
3011 Disable use of RFC5077 session tickets.
3012 Some servers may have problems
3013 understanding the TLS extension due
3014 to ambiguous specification in RFC4507.
3015
195f8adb
AJ
3016 ALL Enable various bug workarounds
3017 suggested as "harmless" by OpenSSL
7905e7be 3018 Be warned that this reduces SSL/TLS
195f8adb
AJ
3019 strength to some attacks.
3020
3f5b28fe
AJ
3021 See the OpenSSL SSL_CTX_set_options documentation
3022 for a more complete list.
3023
3024 GnuTLS options most important are:
3025
3026 %NO_TICKETS
3027 Disable use of RFC5077 session tickets.
3028 Some servers may have problems
3029 understanding the TLS extension due
3030 to ambiguous specification in RFC4507.
3031
3032 See the GnuTLS Priority Strings documentation
3033 for a more complete list.
3034 http://www.gnutls.org/manual/gnutls.html#Priority-Strings
3035
9603207d 3036
86a84cc0
AJ
3037 cafile= PEM file containing CA certificates to use when verifying
3038 the peer certificate. May be repeated to load multiple files.
3039
3040 capath= A directory containing additional CA certificates to
195f8adb 3041 use when verifying the peer certificate.
86a84cc0 3042 Requires OpenSSL or LibreSSL.
9603207d 3043
195f8adb
AJ
3044 crlfile=... A certificate revocation list file to use when
3045 verifying the peer certificate.
9603207d 3046
195f8adb 3047 flags=... Specify various flags modifying the TLS implementation:
9603207d 3048
195f8adb
AJ
3049 DONT_VERIFY_PEER
3050 Accept certificates even if they fail to
3051 verify.
195f8adb
AJ
3052 DONT_VERIFY_DOMAIN
3053 Don't verify the peer certificate
3054 matches the server name
9603207d 3055
435c72b0
AJ
3056 default-ca[=off]
3057 Whether to use the system Trusted CAs. Default is ON.
9603207d 3058
195f8adb
AJ
3059 domain= The peer name as advertised in its certificate.
3060 Used for verifying the correctness of the received peer
3061 certificate. If not specified the peer hostname will be
3062 used.
3063DOC_END
3064
41bd17a4 3065COMMENT_START
3066 SSL OPTIONS
3067 -----------------------------------------------------------------------------
3068COMMENT_END
3069
3070NAME: ssl_unclean_shutdown
cb4f4424 3071IFDEF: USE_OPENSSL
cccac0a2 3072TYPE: onoff
3073DEFAULT: off
41bd17a4 3074LOC: Config.SSL.unclean_shutdown
cccac0a2 3075DOC_START
41bd17a4 3076 Some browsers (especially MSIE) bugs out on SSL shutdown
3077 messages.
cccac0a2 3078DOC_END
3079
41bd17a4 3080NAME: ssl_engine
cb4f4424 3081IFDEF: USE_OPENSSL
cccac0a2 3082TYPE: string
41bd17a4 3083LOC: Config.SSL.ssl_engine
3084DEFAULT: none
cccac0a2 3085DOC_START
41bd17a4 3086 The OpenSSL engine to use. You will need to set this if you
3087 would like to use hardware SSL acceleration for example.
742236c7
AJ
3088
3089 Not supported in builds with OpenSSL v3 or newer.
cccac0a2 3090DOC_END
3091
10a69fc0 3092NAME: sslproxy_session_ttl
cb4f4424 3093IFDEF: USE_OPENSSL
10a69fc0
CT
3094DEFAULT: 300
3095LOC: Config.SSL.session_ttl
3096TYPE: int
3097DOC_START
3098 Sets the timeout value for SSL sessions
3099DOC_END
3100
3101NAME: sslproxy_session_cache_size
cb4f4424 3102IFDEF: USE_OPENSSL
10a69fc0
CT
3103DEFAULT: 2 MB
3104LOC: Config.SSL.sessionCacheSize
3105TYPE: b_size_t
3106DOC_START
3107 Sets the cache size to use for ssl session
3108DOC_END
3109
866be11c
CT
3110NAME: sslproxy_foreign_intermediate_certs
3111IFDEF: USE_OPENSSL
3112DEFAULT: none
3113LOC: Config.ssl_client.foreignIntermediateCertsPath
3114TYPE: string
3115DOC_START
3116 Many origin servers fail to send their full server certificate
3117 chain for verification, assuming the client already has or can
3118 easily locate any missing intermediate certificates.
3119
3120 Squid uses the certificates from the specified file to fill in
3121 these missing chains when trying to validate origin server
3122 certificate chains.
3123
3124 The file is expected to contain zero or more PEM-encoded
3125 intermediate certificates. These certificates are not treated
3126 as trusted root certificates, and any self-signed certificate in
3127 this file will be ignored.
866be11c
CT
3128DOC_END
3129
3c26b00a
CT
3130NAME: sslproxy_cert_sign_hash
3131IFDEF: USE_OPENSSL
3132DEFAULT: none
3133LOC: Config.SSL.certSignHash
3134TYPE: string
3135DOC_START
3136 Sets the hashing algorithm to use when signing generated certificates.
3137 Valid algorithm names depend on the OpenSSL library used. The following
3138 names are usually available: sha1, sha256, sha512, and md5. Please see
3139 your OpenSSL library manual for the available hashes. By default, Squids
3140 that support this option use sha256 hashes.
3141
3142 Squid does not forcefully purge cached certificates that were generated
3143 with an algorithm other than the currently configured one. They remain
3144 in the cache, subject to the regular cache eviction policy, and become
3145 useful if the algorithm changes again.
3146DOC_END
3147
4c9da963 3148NAME: ssl_bump
cb4f4424 3149IFDEF: USE_OPENSSL
caf3666d 3150TYPE: sslproxy_ssl_bump
4c9da963 3151LOC: Config.accessList.ssl_bump
8f165829 3152DEFAULT_DOC: Become a TCP tunnel without decrypting proxied traffic.
4c9da963 3153DEFAULT: none
3154DOC_START
caf3666d
AR
3155 This option is consulted when a CONNECT request is received on
3156 an http_port (or a new connection is intercepted at an
3157 https_port), provided that port was configured with an ssl-bump
3158 flag. The subsequent data on the connection is either treated as
3159 HTTPS and decrypted OR tunneled at TCP level without decryption,
8f165829
AR
3160 depending on the first matching bumping "action".
3161
3162 ssl_bump <action> [!]acl ...
caf3666d 3163
8f165829 3164 The following bumping actions are currently supported:
caf3666d 3165
5d65362c 3166 splice
8f165829
AR
3167 Become a TCP tunnel without decrypting proxied traffic.
3168 This is the default action.
5d65362c
CT
3169
3170 bump
6e0516b3
CT
3171 When used on step SslBump1, establishes a secure connection
3172 with the client first, then connect to the server.
3173 When used on step SslBump2 or SslBump3, establishes a secure
3174 connection with the server and, using a mimicked server
3175 certificate, with the client.
caf3666d 3176
5d65362c 3177 peek
1110989a 3178 Receive client (step SslBump1) or server (step SslBump2)
8f165829
AR
3179 certificate while preserving the possibility of splicing the
3180 connection. Peeking at the server certificate (during step 2)
3181 usually precludes bumping of the connection at step 3.
caf3666d 3182
5d65362c 3183 stare
1110989a 3184 Receive client (step SslBump1) or server (step SslBump2)
8f165829
AR
3185 certificate while preserving the possibility of bumping the
3186 connection. Staring at the server certificate (during step 2)
3187 usually precludes splicing of the connection at step 3.
5d65362c
CT
3188
3189 terminate
3190 Close client and server connections.
3191
1110989a 3192 Backward compatibility actions available at step SslBump1:
caf3666d
AR
3193
3194 client-first
8f165829
AR
3195 Bump the connection. Establish a secure connection with the
3196 client first, then connect to the server. This old mode does
3197 not allow Squid to mimic server SSL certificate and does not
3198 work with intercepted SSL connections.
caf3666d
AR
3199
3200 server-first
8f165829
AR
3201 Bump the connection. Establish a secure connection with the
3202 server first, then establish a secure connection with the
3203 client, using a mimicked server certificate. Works with both
3204 CONNECT requests and intercepted SSL connections, but does
3205 not allow to make decisions based on SSL handshake info.
caf3666d 3206
8f165829 3207 peek-and-splice
9603207d 3208 Decide whether to bump or splice the connection based on
d620ae0e 3209 client-to-squid and server-to-squid SSL hello messages.
8f165829 3210 XXX: Remove.
caf3666d 3211
caf3666d 3212 none
8f165829 3213 Same as the "splice" action.
caf3666d 3214
8f165829
AR
3215 All ssl_bump rules are evaluated at each of the supported bumping
3216 steps. Rules with actions that are impossible at the current step are
3217 ignored. The first matching ssl_bump action wins and is applied at the
3218 end of the current step. If no rules match, the splice action is used.
652fcffd 3219 See the at_step ACL for a list of the supported SslBump steps.
4c9da963 3220
e0c0d54c 3221 This clause supports both fast and slow acl types.
b3567eb5 3222 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
e0855596 3223
652fcffd 3224 See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
caf3666d 3225
e0855596 3226
f3fece95 3227 # Example: Bump all TLS connections except those originating from
638402dd 3228 # localhost or those going to example.com.
e0855596 3229
f3fece95 3230 acl broken_sites ssl::server_name .example.com
8f165829
AR
3231 ssl_bump splice localhost
3232 ssl_bump splice broken_sites
3233 ssl_bump bump all
4c9da963 3234DOC_END
3235
4c9da963 3236NAME: sslproxy_cert_error
cb4f4424 3237IFDEF: USE_OPENSSL
4c9da963 3238DEFAULT: none
638402dd 3239DEFAULT_DOC: Server certificate errors terminate the transaction.
4c9da963 3240LOC: Config.ssl_client.cert_error
3241TYPE: acl_access
3242DOC_START
3243 Use this ACL to bypass server certificate validation errors.
3244
3245 For example, the following lines will bypass all validation errors
3b8f558c 3246 when talking to servers for example.com. All other
4c9da963 3247 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
3248
a87bfd3b
AR
3249 acl BrokenButTrustedServers dstdomain example.com
3250 sslproxy_cert_error allow BrokenButTrustedServers
4c9da963 3251 sslproxy_cert_error deny all
3252
b3567eb5
FC
3253 This clause only supports fast acl types.
3254 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3255 Using slow acl types may result in server crashes
4c9da963 3256
3257 Without this option, all server certificate validation errors
638402dd 3258 terminate the transaction to protect Squid and the client.
4c9da963 3259
0ad3ff51
CT
3260 SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
3261 but should not happen unless your OpenSSL library is buggy.
3262
638402dd
AJ
3263 SECURITY WARNING:
3264 Bypassing validation errors is dangerous because an
3265 error usually implies that the server cannot be trusted
3266 and the connection may be insecure.
4c9da963 3267
638402dd 3268 See also: sslproxy_flags and DONT_VERIFY_PEER.
4c9da963 3269DOC_END
3270
aebe6888 3271NAME: sslproxy_cert_sign
cb4f4424 3272IFDEF: USE_OPENSSL
aebe6888 3273DEFAULT: none
10d914f6
CT
3274POSTSCRIPTUM: signUntrusted ssl::certUntrusted
3275POSTSCRIPTUM: signSelf ssl::certSelfSigned
3276POSTSCRIPTUM: signTrusted all
aebe6888
CT
3277TYPE: sslproxy_cert_sign
3278LOC: Config.ssl_client.cert_sign
3279DOC_START
3280
69742b76 3281 sslproxy_cert_sign <signing algorithm> acl ...
aebe6888 3282
69742b76 3283 The following certificate signing algorithms are supported:
638402dd 3284
aebe6888 3285 signTrusted
69742b76
AR
3286 Sign using the configured CA certificate which is usually
3287 placed in and trusted by end-user browsers. This is the
3288 default for trusted origin server certificates.
638402dd 3289
aebe6888 3290 signUntrusted
69742b76
AR
3291 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
3292 This is the default for untrusted origin server certificates
3293 that are not self-signed (see ssl::certUntrusted).
638402dd 3294
aebe6888 3295 signSelf
69742b76 3296 Sign using a self-signed certificate with the right CN to
aebe6888 3297 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
69742b76
AR
3298 browser. This is the default for self-signed origin server
3299 certificates (see ssl::certSelfSigned).
aebe6888 3300
cf1c09f6
CT
3301 This clause only supports fast acl types.
3302
69742b76
AR
3303 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
3304 signing algorithm to generate the certificate and ignores all
3305 subsequent sslproxy_cert_sign options (the first match wins). If no
3306 acl(s) match, the default signing algorithm is determined by errors
3307 detected when obtaining and validating the origin server certificate.
cf1c09f6 3308
4b0d23b7
CT
3309 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
3310 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
3311 CONNECT request that carries a domain name. In all other cases (CONNECT
3312 to an IP address or an intercepted SSL connection), Squid cannot detect
3313 the domain mismatch at certificate generation time when
3314 bump-server-first is used.
aebe6888
CT
3315DOC_END
3316
638402dd 3317NAME: sslproxy_cert_adapt
cb4f4424 3318IFDEF: USE_OPENSSL
fb2178bb
CT
3319DEFAULT: none
3320TYPE: sslproxy_cert_adapt
3321LOC: Config.ssl_client.cert_adapt
3322DOC_START
9603207d 3323
fb2178bb
CT
3324 sslproxy_cert_adapt <adaptation algorithm> acl ...
3325
69742b76 3326 The following certificate adaptation algorithms are supported:
638402dd 3327
fb2178bb 3328 setValidAfter
69742b76
AR
3329 Sets the "Not After" property to the "Not After" property of
3330 the CA certificate used to sign generated certificates.
638402dd 3331
fb2178bb 3332 setValidBefore
69742b76
AR
3333 Sets the "Not Before" property to the "Not Before" property of
3334 the CA certificate used to sign generated certificates.
638402dd 3335
69742b76 3336 setCommonName or setCommonName{CN}
9603207d 3337 Sets Subject.CN property to the host name specified as a
69742b76
AR
3338 CN parameter or, if no explicit CN parameter was specified,
3339 extracted from the CONNECT request. It is a misconfiguration
3340 to use setCommonName without an explicit parameter for
3341 intercepted or tproxied SSL connections.
9603207d 3342
cf1c09f6
CT
3343 This clause only supports fast acl types.
3344
69742b76
AR
3345 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
3346 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
3347 corresponding adaptation algorithm to generate the certificate and
3348 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
3349 group (i.e., the first match wins within each algorithm group). If no
3350 acl(s) match, the default mimicking action takes place.
cf1c09f6 3351
4b0d23b7
CT
3352 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
3353 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
3354 CONNECT request that carries a domain name. In all other cases (CONNECT
3355 to an IP address or an intercepted SSL connection), Squid cannot detect
3356 the domain mismatch at certificate generation time when
3357 bump-server-first is used.
fb2178bb
CT
3358DOC_END
3359
41bd17a4 3360NAME: sslpassword_program
cb4f4424 3361IFDEF: USE_OPENSSL
41bd17a4 3362DEFAULT: none
3363LOC: Config.Program.ssl_password
3364TYPE: string
5473c134 3365DOC_START
41bd17a4 3366 Specify a program used for entering SSL key passphrases
3367 when using encrypted SSL certificate keys. If not specified
3368 keys must either be unencrypted, or Squid started with the -N
3369 option to allow it to query interactively for the passphrase.
7acb9ddd
HN
3370
3371 The key file name is given as argument to the program allowing
3372 selection of the right password if you have multiple encrypted
3373 keys.
5473c134 3374DOC_END
3375
95d2589c 3376COMMENT_START
9603207d 3377 OPTIONS RELATING TO EXTERNAL SSL_CRTD
95d2589c
CT
3378 -----------------------------------------------------------------------------
3379COMMENT_END
3380
3381NAME: sslcrtd_program
9603207d 3382TYPE: eol
95d2589c
CT
3383IFDEF: USE_SSL_CRTD
3384DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
3385LOC: Ssl::TheConfig.ssl_crtd
3386DOC_START
cb0b3d63
AJ
3387 Specify the location and options of the executable for certificate
3388 generator.
a2a12dec
MM
3389
3390 @DEFAULT_SSL_CRTD@ program can use a disk cache to improve response
3391 times on repeated requests. To enable caching, specify -s and -M
3392 parameters. If those parameters are not given, the program generates
3393 a new certificate on every request.
3394
95d2589c
CT
3395 For more information use:
3396 @DEFAULT_SSL_CRTD@ -h
3397DOC_END
3398
3399NAME: sslcrtd_children
3400TYPE: HelperChildConfig
3401IFDEF: USE_SSL_CRTD
3402DEFAULT: 32 startup=5 idle=1
3403LOC: Ssl::TheConfig.ssl_crtdChildren
3404DOC_START
79933cd6
AR
3405 Specifies the maximum number of certificate generation processes that
3406 Squid may spawn (numberofchildren) and several related options. Using
3407 too few of these helper processes (a.k.a. "helpers") creates request
3408 queues. Using too many helpers wastes your system resources. Squid
3409 does not support spawning more than 32 helpers.
3410
3411 Usage: numberofchildren [option]...
3412
95d2589c
CT
3413 The startup= and idle= options allow some measure of skew in your
3414 tuning.
9603207d 3415
95d2589c 3416 startup=N
9603207d 3417
95d2589c
CT
3418 Sets the minimum number of processes to spawn when Squid
3419 starts or reconfigures. When set to zero the first request will
3420 cause spawning of the first child process to handle it.
9603207d 3421
95d2589c
CT
3422 Starting too few children temporary slows Squid under load while it
3423 tries to spawn enough additional processes to cope with traffic.
9603207d 3424
95d2589c 3425 idle=N
9603207d 3426
95d2589c
CT
3427 Sets a minimum of how many processes Squid is to try and keep available
3428 at all times. When traffic begins to rise above what the existing
3429 processes can handle this many more will be spawned up to the maximum
3430 configured. A minimum setting of 1 is required.
6825b101
CT
3431
3432 queue-size=N
3433
79933cd6
AR
3434 Sets the maximum number of queued requests. A request is queued when
3435 no existing child is idle and no new child can be started due to
3436 numberofchildren limit. If the queued requests exceed queue size for
3437 more than 3 minutes squid aborts its operation. The default value is
3438 set to 2*numberofchildren.
9603207d 3439
95d2589c
CT
3440 You must have at least one ssl_crtd process.
3441DOC_END
3442
2cef0ca6
AR
3443NAME: sslcrtvalidator_program
3444TYPE: eol
cb4f4424 3445IFDEF: USE_OPENSSL
2cef0ca6
AR
3446DEFAULT: none
3447LOC: Ssl::TheConfig.ssl_crt_validator
3448DOC_START
3449 Specify the location and options of the executable for ssl_crt_validator
638402dd
AJ
3450 process.
3451
72247610 3452 Usage: sslcrtvalidator_program [ttl=...] [cache=n] path ...
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3453
3454 Options:
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AJ
3455
3456 cache=bytes
3457 Limits how much memory Squid can use for caching validator
3458 responses. The default is 67108864 (i.e. 64 MB).
3459 Reconfiguration purges any excess entries. To disable caching,
3460 use cache=0. Currently, cache entry sizes are seriously
3461 underestimated. Even with that bug, a typical estimate for a
3462 single cache entry size would be at least a few kilobytes (the
3463 size of the PEM certificates sent to the validator).
3464
3465 ttl=<seconds|"infinity">
3466 Approximately how long Squid may reuse the validator results
3467 for. The default is 3600 (i.e. 1 hour). Using ttl=infinity
3468 disables TTL checks. Reconfiguration does not affect TTLs of
3469 the already cached entries. To disable caching, use zero cache
3470 size, not zero TTL -- zero TTL allows reuse for the remainder
3471 of the second when the result was cached.
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AR
3472DOC_END
3473
3474NAME: sslcrtvalidator_children
3475TYPE: HelperChildConfig
cb4f4424 3476IFDEF: USE_OPENSSL
413bb969 3477DEFAULT: 32 startup=5 idle=1 concurrency=1
2cef0ca6
AR
3478LOC: Ssl::TheConfig.ssl_crt_validator_Children
3479DOC_START
79933cd6
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3480 Specifies the maximum number of certificate validation processes that
3481 Squid may spawn (numberofchildren) and several related options. Using
3482 too few of these helper processes (a.k.a. "helpers") creates request
3483 queues. Using too many helpers wastes your system resources. Squid
3484 does not support spawning more than 32 helpers.
3485
3486 Usage: numberofchildren [option]...
9603207d 3487
2cef0ca6
AR
3488 The startup= and idle= options allow some measure of skew in your
3489 tuning.
9603207d 3490
2cef0ca6 3491 startup=N
9603207d 3492
2cef0ca6
AR
3493 Sets the minimum number of processes to spawn when Squid
3494 starts or reconfigures. When set to zero the first request will
3495 cause spawning of the first child process to handle it.
9603207d 3496
2cef0ca6
AR
3497 Starting too few children temporary slows Squid under load while it
3498 tries to spawn enough additional processes to cope with traffic.
9603207d 3499
2cef0ca6 3500 idle=N
9603207d 3501
2cef0ca6
AR
3502 Sets a minimum of how many processes Squid is to try and keep available
3503 at all times. When traffic begins to rise above what the existing
3504 processes can handle this many more will be spawned up to the maximum
3505 configured. A minimum setting of 1 is required.
4a77bb4e
CT
3506
3507 concurrency=
9603207d 3508
4a77bb4e 3509 The number of requests each certificate validator helper can handle in
2f8abb64 3510 parallel. A value of 0 indicates the certificate validator does not
dffc462a 3511 support concurrency. Defaults to 1.
9603207d 3512
4a77bb4e
CT
3513 When this directive is set to a value >= 1 then the protocol
3514 used to communicate with the helper is modified to include
3515 a request ID in front of the request/response. The request
3516 ID from the request must be echoed back with the response
3517 to that request.
6825b101
CT
3518
3519 queue-size=N
3520
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AR
3521 Sets the maximum number of queued requests. A request is queued when
3522 no existing child can accept it due to concurrency limit and no new
3523 child can be started due to numberofchildren limit. If the queued
3524 requests exceed queue size for more than 3 minutes squid aborts its
3525 operation. The default value is set to 2*numberofchildren.
9603207d 3526
2cef0ca6
AR
3527 You must have at least one ssl_crt_validator process.
3528DOC_END
3529
cccac0a2 3530COMMENT_START
41bd17a4 3531 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
cccac0a2 3532 -----------------------------------------------------------------------------
3533COMMENT_END
3534
41bd17a4 3535NAME: cache_peer
3536TYPE: peer
3537DEFAULT: none
3538LOC: Config.peers
cccac0a2 3539DOC_START
41bd17a4 3540 To specify other caches in a hierarchy, use the format:
9603207d 3541
41bd17a4 3542 cache_peer hostname type http-port icp-port [options]
9603207d 3543
41bd17a4 3544 For example,
9603207d 3545
41bd17a4 3546 # proxy icp
3547 # hostname type port port options
3548 # -------------------- -------- ----- ----- -----------
2b94f655 3549 cache_peer parent.foo.net parent 3128 3130 default
41bd17a4 3550 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
3551 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2e9993e1 3552 cache_peer example.com parent 80 0 default
9603207d 3553 cache_peer cdn.example.com sibling 3128 0
3554
2b94f655 3555 type: either 'parent', 'sibling', or 'multicast'.
9603207d 3556
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AJ
3557 proxy-port: The port number where the peer accept HTTP requests.
3558 For other Squid proxies this is usually 3128
3559 For web servers this is usually 80
9603207d 3560
2b94f655
AJ
3561 icp-port: Used for querying neighbor caches about objects.
3562 Set to 0 if the peer does not support ICP or HTCP.
3563 See ICP and HTCP options below for additional details.
9603207d 3564
3565
2b94f655 3566 ==== ICP OPTIONS ====
9603207d 3567
2b94f655
AJ
3568 You MUST also set icp_port and icp_access explicitly when using these options.
3569 The defaults will prevent peer traffic using ICP.
9603207d 3570
3571
2b94f655 3572 no-query Disable ICP queries to this neighbor.
9603207d 3573
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AJ
3574 multicast-responder
3575 Indicates the named peer is a member of a multicast group.
3576 ICP queries will not be sent directly to the peer, but ICP
3577 replies will be accepted from it.
9603207d 3578
2b94f655
AJ
3579 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
3580 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
9603207d 3581
2b94f655
AJ
3582 background-ping
3583 To only send ICP queries to this neighbor infrequently.
3584 This is used to keep the neighbor round trip time updated
3585 and is usually used in conjunction with weighted-round-robin.
9603207d 3586
3587
2b94f655 3588 ==== HTCP OPTIONS ====
9603207d 3589
2b94f655
AJ
3590 You MUST also set htcp_port and htcp_access explicitly when using these options.
3591 The defaults will prevent peer traffic using HTCP.
9603207d 3592
3593
2b94f655
AJ
3594 htcp Send HTCP, instead of ICP, queries to the neighbor.
3595 You probably also want to set the "icp-port" to 4827
18191440
AJ
3596 instead of 3130. This directive accepts a comma separated
3597 list of options described below.
9603207d 3598
18191440 3599 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
9603207d 3600
18191440 3601 htcp=no-clr Send HTCP to the neighbor but without
2b94f655 3602 sending any CLR requests. This cannot be used with
18191440 3603 only-clr.
9603207d 3604
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AJ
3605 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
3606 This cannot be used with no-clr.
9603207d 3607
18191440 3608 htcp=no-purge-clr
2b94f655
AJ
3609 Send HTCP to the neighbor including CLRs but only when
3610 they do not result from PURGE requests.
9603207d 3611
18191440 3612 htcp=forward-clr
2b94f655 3613 Forward any HTCP CLR requests this proxy receives to the peer.
9603207d 3614
3615
2b94f655 3616 ==== PEER SELECTION METHODS ====
9603207d 3617
2b94f655
AJ
3618 The default peer selection method is ICP, with the first responding peer
3619 being used as source. These options can be used for better load balancing.
9603207d 3620
3621
2b94f655
AJ
3622 default This is a parent cache which can be used as a "last-resort"
3623 if a peer cannot be located by any of the peer-selection methods.
3624 If specified more than once, only the first is used.
9603207d 3625
2b94f655
AJ
3626 round-robin Load-Balance parents which should be used in a round-robin
3627 fashion in the absence of any ICP queries.
3628 weight=N can be used to add bias.
9603207d 3629
2b94f655
AJ
3630 weighted-round-robin
3631 Load-Balance parents which should be used in a round-robin
3632 fashion with the frequency of each parent being based on the
3633 round trip time. Closer parents are used more often.
3634 Usually used for background-ping parents.
3635 weight=N can be used to add bias.
9603207d 3636
2b94f655
AJ
3637 carp Load-Balance parents which should be used as a CARP array.
3638 The requests will be distributed among the parents based on the
3639 CARP load balancing hash function based on their weight.
9603207d 3640
2b94f655 3641 userhash Load-balance parents based on the client proxy_auth or ident username.
9603207d 3642
2b94f655 3643 sourcehash Load-balance parents based on the client source IP.
8a368316
AJ
3644
3645 multicast-siblings
3646 To be used only for cache peers of type "multicast".
3647 ALL members of this multicast group have "sibling"
2e9993e1 3648 relationship with it, not "parent". This is to a multicast
8a368316
AJ
3649 group when the requested object would be fetched only from
3650 a "parent" cache, anyway. It's useful, e.g., when
3651 configuring a pool of redundant Squid proxies, being
3652 members of the same multicast group.
9603207d 3653
3654
2b94f655 3655 ==== PEER SELECTION OPTIONS ====
9603207d 3656
2b94f655
AJ
3657 weight=N use to affect the selection of a peer during any weighted
3658 peer-selection mechanisms.
3659 The weight must be an integer; default is 1,
3660 larger weights are favored more.
3661 This option does not affect parent selection if a peering
3662 protocol is not in use.
9603207d 3663
2b94f655
AJ
3664 basetime=N Specify a base amount to be subtracted from round trip
3665 times of parents.
3666 It is subtracted before division by weight in calculating
3667 which parent to fectch from. If the rtt is less than the
3668 base time the rtt is set to a minimal value.
9603207d 3669
3c72389f
AJ
3670 ttl=N Specify a TTL to use when sending multicast ICP queries
3671 to this address.
2b94f655
AJ
3672 Only useful when sending to a multicast group.
3673 Because we don't accept ICP replies from random
3674 hosts, you must configure other group members as
3675 peers with the 'multicast-responder' option.
9603207d 3676
2b94f655
AJ
3677 no-delay To prevent access to this neighbor from influencing the
3678 delay pools.
9603207d 3679
2b94f655
AJ
3680 digest-url=URL Tell Squid to fetch the cache digest (if digests are
3681 enabled) for this host from the specified URL rather
3682 than the Squid default location.
9603207d 3683
3684
de03b596 3685 ==== CARP OPTIONS ====
9603207d 3686
de03b596
FC
3687 carp-key=key-specification
3688 use a different key than the full URL to hash against the peer.
9603207d 3689 the key-specification is a comma-separated list of the keywords
de03b596
FC
3690 scheme, host, port, path, params
3691 Order is not important.
9603207d 3692
2b94f655 3693 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
9603207d 3694
2b94f655
AJ
3695 originserver Causes this parent to be contacted as an origin server.
3696 Meant to be used in accelerator setups when the peer
3697 is a web server.
9603207d 3698
2b94f655
AJ
3699 forceddomain=name
3700 Set the Host header of requests forwarded to this peer.
3701 Useful in accelerator setups where the server (peer)
3702 expects a certain domain name but clients may request
3703 others. ie example.com or www.example.com
9603207d 3704
2b94f655 3705 no-digest Disable request of cache digests.
9603207d 3706
2b94f655
AJ
3707 no-netdb-exchange
3708 Disables requesting ICMP RTT database (NetDB).
9603207d 3709
3710
2b94f655 3711 ==== AUTHENTICATION OPTIONS ====
9603207d 3712
2b94f655
AJ
3713 login=user:password
3714 If this is a personal/workgroup proxy and your parent
3715 requires proxy authentication.
9603207d 3716
2b94f655
AJ
3717 Note: The string can include URL escapes (i.e. %20 for
3718 spaces). This also means % must be written as %%.
9603207d 3719
11e4c5e5
AJ
3720 login=PASSTHRU
3721 Send login details received from client to this peer.
3722 Both Proxy- and WWW-Authorization headers are passed
3723 without alteration to the peer.
3724 Authentication is not required by Squid for this to work.
9603207d 3725
11e4c5e5
AJ
3726 Note: This will pass any form of authentication but
3727 only Basic auth will work through a proxy unless the
3728 connection-auth options are also used.
ee0b94f4 3729
2b94f655
AJ
3730 login=PASS Send login details received from client to this peer.
3731 Authentication is not required by this option.
9603207d 3732
2b94f655
AJ
3733 If there are no client-provided authentication headers
3734 to pass on, but username and password are available
ee0b94f4
HN
3735 from an external ACL user= and password= result tags
3736 they may be sent instead.
9603207d 3737
2b94f655
AJ
3738 Note: To combine this with proxy_auth both proxies must
3739 share the same user database as HTTP only allows for
3740 a single login (one for proxy, one for origin server).
3741 Also be warned this will expose your users proxy
3742 password to the peer. USE WITH CAUTION
9603207d 3743
2b94f655
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3744 login=*:password
3745 Send the username to the upstream cache, but with a
3746 fixed password. This is meant to be used when the peer
3747 is in another administrative domain, but it is still
3748 needed to identify each user.
3749 The star can optionally be followed by some extra
3750 information which is added to the username. This can
3751 be used to identify this proxy to the peer, similar to
3752 the login=username:password option above.
9603207d 3753
9ca29d23
AJ
3754 login=NEGOTIATE
3755 If this is a personal/workgroup proxy and your parent
3756 requires a secure proxy authentication.
3757 The first principal from the default keytab or defined by
9603207d 3758 the environment variable KRB5_KTNAME will be used.
3759
63f03f79
PL
3760 WARNING: The connection may transmit requests from multiple
3761 clients. Negotiate often assumes end-to-end authentication
3762 and a single-client. Which is not strictly true here.
9603207d 3763
9ca29d23
AJ
3764 login=NEGOTIATE:principal_name
3765 If this is a personal/workgroup proxy and your parent
9603207d 3766 requires a secure proxy authentication.
9ca29d23
AJ
3767 The principal principal_name from the default keytab or
3768 defined by the environment variable KRB5_KTNAME will be
3769 used.
9603207d 3770
63f03f79
PL
3771 WARNING: The connection may transmit requests from multiple
3772 clients. Negotiate often assumes end-to-end authentication
3773 and a single-client. Which is not strictly true here.
9603207d 3774
2b94f655
AJ
3775 connection-auth=on|off
3776 Tell Squid that this peer does or not support Microsoft
3777 connection oriented authentication, and any such
3778 challenges received from there should be ignored.
3779 Default is auto to automatically determine the status
3780 of the peer.
9603207d 3781
9825b398
AJ
3782 auth-no-keytab
3783 Do not use a keytab to authenticate to a peer when
3784 login=NEGOTIATE is specified. Let the GSSAPI
3785 implementation determine which already existing
3786 credentials cache to use instead.
9603207d 3787
3788
2b94f655 3789 ==== SSL / HTTPS / TLS OPTIONS ====
9603207d 3790
0ff7e52d 3791 tls Encrypt connections to this peer with TLS.
9603207d 3792
2b94f655 3793 sslcert=/path/to/ssl/certificate
51e09c08 3794 A client X.509 certificate to use when connecting to
2b94f655 3795 this peer.
9603207d 3796
2b94f655 3797 sslkey=/path/to/ssl/key
51e09c08
AJ
3798 The private key corresponding to sslcert above.
3799
3800 If sslkey= is not specified sslcert= is assumed to
3801 reference a PEM file containing both the certificate
3802 and private key.
9603207d 3803
2b94f655
AJ
3804 sslcipher=... The list of valid SSL ciphers to use when connecting
3805 to this peer.
1cc44095
AJ
3806
3807 tls-min-version=1.N
3808 The minimum TLS protocol version to permit. To control
3f5b28fe 3809 SSLv3 use the tls-options= parameter.
1cc44095
AJ
3810 Supported Values: 1.0 (default), 1.1, 1.2
3811
3f5b28fe 3812 tls-options=... Specify various TLS implementation options.
943c5f16 3813
3f5b28fe 3814 OpenSSL options most important are:
1f1f29e8 3815
3f5b28fe 3816 NO_SSLv3 Disallow the use of SSLv3
1f1f29e8 3817
943c5f16
HN
3818 SINGLE_DH_USE
3819 Always create a new key when using
3820 temporary/ephemeral DH key exchanges
1f1f29e8 3821
ce0adf1a 3822 NO_TICKET
1f1f29e8
AJ
3823 Disable use of RFC5077 session tickets.
3824 Some servers may have problems
3825 understanding the TLS extension due
3826 to ambiguous specification in RFC4507.
3827
943c5f16
HN
3828 ALL Enable various bug workarounds
3829 suggested as "harmless" by OpenSSL
3830 Be warned that this reduces SSL/TLS
3831 strength to some attacks.
3832
3833 See the OpenSSL SSL_CTX_set_options documentation for a
3834 more complete list.
3f5b28fe
AJ
3835
3836 GnuTLS options most important are:
3837
3838 %NO_TICKETS
3839 Disable use of RFC5077 session tickets.
3840 Some servers may have problems
3841 understanding the TLS extension due
3842 to ambiguous specification in RFC4507.
3843
3844 See the GnuTLS Priority Strings documentation
3845 for a more complete list.
3846 http://www.gnutls.org/manual/gnutls.html#Priority-Strings
3847
86a84cc0
AJ
3848 tls-cafile= PEM file containing CA certificates to use when verifying
3849 the peer certificate. May be repeated to load multiple files.
9603207d 3850
2b94f655
AJ
3851 sslcapath=... A directory containing additional CA certificates to
3852 use when verifying the peer certificate.
86a84cc0 3853 Requires OpenSSL or LibreSSL.
9603207d 3854
2b94f655
AJ
3855 sslcrlfile=... A certificate revocation list file to use when
3856 verifying the peer certificate.
9603207d 3857
2b94f655 3858 sslflags=... Specify various flags modifying the SSL implementation:
9603207d 3859
41bd17a4 3860 DONT_VERIFY_PEER
3861 Accept certificates even if they fail to
3862 verify.
1f1f29e8 3863
41bd17a4 3864 DONT_VERIFY_DOMAIN
3865 Don't verify the peer certificate
3866 matches the server name
9603207d 3867
2b94f655
AJ
3868 ssldomain= The peer name as advertised in it's certificate.
3869 Used for verifying the correctness of the received peer
3870 certificate. If not specified the peer hostname will be
3871 used.
9603207d 3872
bad9c5e4 3873 front-end-https[=off|on|auto]
2b94f655
AJ
3874 Enable the "Front-End-Https: On" header needed when
3875 using Squid as a SSL frontend in front of Microsoft OWA.
3876 See MS KB document Q307347 for details on this header.
3877 If set to auto the header will only be added if the
3878 request is forwarded as a https:// URL.
9603207d 3879
435c72b0
AJ
3880 tls-default-ca[=off]
3881 Whether to use the system Trusted CAs. Default is ON.
9603207d 3882
b05d749d
AJ
3883 tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
3884
2b94f655 3885 ==== GENERAL OPTIONS ====
9603207d 3886
2b94f655
AJ
3887 connect-timeout=N
3888 A peer-specific connect timeout.
3889 Also see the peer_connect_timeout directive.
9603207d 3890
2b94f655
AJ
3891 connect-fail-limit=N
3892 How many times connecting to a peer must fail before
e8dca475
CT
3893 it is marked as down. Standby connection failures
3894 count towards this limit. Default is 10.
9603207d 3895
2b94f655
AJ
3896 allow-miss Disable Squid's use of only-if-cached when forwarding
3897 requests to siblings. This is primarily useful when
a5bb0c26
AR
3898 icp_hit_stale is used by the sibling. Excessive use
3899 of this option may result in forwarding loops. One way
3900 to prevent peering loops when using this option, is to
3901 deny cache peer usage on requests from a peer:
3902 acl fromPeer ...
3903 cache_peer_access peerName deny fromPeer
9603207d 3904
e8dca475
CT
3905 max-conn=N Limit the number of concurrent connections the Squid
3906 may open to this peer, including already opened idle
3907 and standby connections. There is no peer-specific
3908 connection limit by default.
9603207d 3909
e8dca475
CT
3910 A peer exceeding the limit is not used for new
3911 requests unless a standby connection is available.
9603207d 3912
e8dca475
CT
3913 max-conn currently works poorly with idle persistent
3914 connections: When a peer reaches its max-conn limit,
3915 and there are idle persistent connections to the peer,
3916 the peer may not be selected because the limiting code
3917 does not know whether Squid can reuse those idle
3918 connections.
9603207d 3919
e8dca475
CT
3920 standby=N Maintain a pool of N "hot standby" connections to an
3921 UP peer, available for requests when no idle
3922 persistent connection is available (or safe) to use.
3923 By default and with zero N, no such pool is maintained.
3924 N must not exceed the max-conn limit (if any).
9603207d 3925
e8dca475
CT
3926 At start or after reconfiguration, Squid opens new TCP
3927 standby connections until there are N connections
3928 available and then replenishes the standby pool as
3929 opened connections are used up for requests. A used
3930 connection never goes back to the standby pool, but
3931 may go to the regular idle persistent connection pool
3932 shared by all peers and origin servers.
9603207d 3933
e8dca475
CT
3934 Squid never opens multiple new standby connections
3935 concurrently. This one-at-a-time approach minimizes
3936 flooding-like effect on peers. Furthermore, just a few
3937 standby connections should be sufficient in most cases
3938 to supply most new requests with a ready-to-use
3939 connection.
9603207d 3940
e8dca475
CT
3941 Standby connections obey server_idle_pconn_timeout.
3942 For the feature to work as intended, the peer must be
3943 configured to accept and keep them open longer than
3944 the idle timeout at the connecting Squid, to minimize
3945 race conditions typical to idle used persistent
3946 connections. Default request_timeout and
3947 server_idle_pconn_timeout values ensure such a
3948 configuration.
9603207d 3949
2b94f655
AJ
3950 name=xxx Unique name for the peer.
3951 Required if you have multiple peers on the same host
3952 but different ports.
3953 This name can be used in cache_peer_access and similar
a5bb0c26 3954 directives to identify the peer.
2b94f655
AJ
3955 Can be used by outgoing access controls through the
3956 peername ACL type.
9603207d 3957
b0758e04
AJ
3958 no-tproxy Do not use the client-spoof TPROXY support when forwarding
3959 requests to this peer. Use normal address selection instead.
0d901ef4 3960 This overrides the spoof_client_ip ACL.
9603207d 3961
2b94f655 3962 proxy-only objects fetched from the peer will not be stored locally.
9603207d 3963
41bd17a4 3964DOC_END
cccac0a2 3965
41bd17a4 3966NAME: cache_peer_access
3967TYPE: peer_access
3968DEFAULT: none
a5bb0c26 3969DEFAULT_DOC: No peer usage restrictions.
41bd17a4 3970LOC: none
3971DOC_START
a5bb0c26 3972 Restricts usage of cache_peer proxies.
cccac0a2 3973
638402dd 3974 Usage:
a5bb0c26
AR
3975 cache_peer_access peer-name allow|deny [!]aclname ...
3976
3977 For the required peer-name parameter, use either the value of the
3978 cache_peer name=value parameter or, if name=value is missing, the
3979 cache_peer hostname parameter.
3980
3981 This directive narrows down the selection of peering candidates, but
3982 does not determine the order in which the selected candidates are
3983 contacted. That order is determined by the peer selection algorithms
3984 (see PEER SELECTION sections in the cache_peer documentation).
3985
3986 If a deny rule matches, the corresponding peer will not be contacted
3987 for the current transaction -- Squid will not send ICP queries and
3988 will not forward HTTP requests to that peer. An allow match leaves
3989 the corresponding peer in the selection. The first match for a given
3990 peer wins for that peer.
3991
3992 The relative order of cache_peer_access directives for the same peer
3993 matters. The relative order of any two cache_peer_access directives
3994 for different peers does not matter. To ease interpretation, it is a
3995 good idea to group cache_peer_access directives for the same peer
3996 together.
3997
3998 A single cache_peer_access directive may be evaluated multiple times
3999 for a given transaction because individual peer selection algorithms
4000 may check it independently from each other. These redundant checks
4001 may be optimized away in future Squid versions.
4002
4003 This clause only supports fast acl types.
4004 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
dd9b1776 4005
41bd17a4 4006DOC_END
dd9b1776 4007
41bd17a4 4008NAME: neighbor_type_domain
4009TYPE: hostdomaintype
4010DEFAULT: none
638402dd 4011DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
41bd17a4 4012LOC: none
4013DOC_START
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4014 Modify the cache_peer neighbor type when passing requests
4015 about specific domains to the peer.
cccac0a2 4016
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4017 Usage:
4018 neighbor_type_domain neighbor parent|sibling domain domain ...
6bf4f823 4019
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4020 For example:
4021 cache_peer foo.example.com parent 3128 3130
4022 neighbor_type_domain foo.example.com sibling .au .de
6bf4f823 4023
638402dd
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4024 The above configuration treats all requests to foo.example.com as a
4025 parent proxy unless the request is for a .au or .de ccTLD domain name.
41bd17a4 4026DOC_END
6bf4f823 4027
41bd17a4 4028NAME: dead_peer_timeout
4029COMMENT: (seconds)
4030DEFAULT: 10 seconds
4031TYPE: time_t
4032LOC: Config.Timeout.deadPeer
4033DOC_START
4034 This controls how long Squid waits to declare a peer cache
4035 as "dead." If there are no ICP replies received in this
4036 amount of time, Squid will declare the peer dead and not
4037 expect to receive any further ICP replies. However, it
4038 continues to send ICP queries, and will mark the peer as
4039 alive upon receipt of the first subsequent ICP reply.
699acd19 4040
41bd17a4 4041 This timeout also affects when Squid expects to receive ICP
4042 replies from peers. If more than 'dead_peer' seconds have
4043 passed since the last ICP reply was received, Squid will not
4044 expect to receive an ICP reply on the next query. Thus, if
4045 your time between requests is greater than this timeout, you
4046 will see a lot of requests sent DIRECT to origin servers
4047 instead of to your parents.
4048DOC_END
cccac0a2 4049
437823b4 4050NAME: forward_max_tries
6c367206 4051DEFAULT: 25
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AJ
4052TYPE: int
4053LOC: Config.forward_max_tries
4054DOC_START
3eebd267
EB
4055 Limits the number of attempts to forward the request.
4056
4057 For the purpose of this limit, Squid counts all high-level request
4058 forwarding attempts, including any same-destination retries after
4059 certain persistent connection failures and any attempts to use a
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4060 different peer. However, these low-level attempts are not counted:
4061 * connection reopening attempts (enabled using connect_retries)
4062 * unfinished Happy Eyeballs connection attempts (prevented by setting
4063 happy_eyeballs_connect_limit to 0)
9603207d 4064
3eebd267 4065 See also: forward_timeout and connect_retries.
437823b4
AJ
4066DOC_END
4067
41bd17a4 4068COMMENT_START
4069 MEMORY CACHE OPTIONS
4070 -----------------------------------------------------------------------------
4071COMMENT_END
4072
4073NAME: cache_mem
4074COMMENT: (bytes)
4075TYPE: b_size_t
df2eec10 4076DEFAULT: 256 MB
41bd17a4 4077LOC: Config.memMaxSize
6b698a21 4078DOC_START
41bd17a4 4079 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
4080 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
4081 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
4082 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
4083
4084 'cache_mem' specifies the ideal amount of memory to be used
4085 for:
4086 * In-Transit objects
4087 * Hot Objects
4088 * Negative-Cached objects
4089
4090 Data for these objects are stored in 4 KB blocks. This
4091 parameter specifies the ideal upper limit on the total size of
4092 4 KB blocks allocated. In-Transit objects take the highest
4093 priority.
4094
4095 In-transit objects have priority over the others. When
4096 additional space is needed for incoming data, negative-cached
4097 and hot objects will be released. In other words, the
4098 negative-cached and hot objects will fill up any unused space
4099 not needed for in-transit objects.
4100
4101 If circumstances require, this limit will be exceeded.
4102 Specifically, if your incoming request rate requires more than
4103 'cache_mem' of memory to hold in-transit objects, Squid will
4104 exceed this limit to satisfy the new requests. When the load
4105 decreases, blocks will be freed until the high-water mark is
4106 reached. Thereafter, blocks will be used to store hot
4107 objects.
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4108
4109 If shared memory caching is enabled, Squid does not use the shared
4110 cache space for in-transit objects, but they still consume as much
4111 local memory as they need. For more details about the shared memory
4112 cache, see memory_cache_shared.
6b698a21 4113DOC_END
0976f8db 4114
41bd17a4 4115NAME: maximum_object_size_in_memory
4116COMMENT: (bytes)
4117TYPE: b_size_t
df2eec10 4118DEFAULT: 512 KB
41bd17a4 4119LOC: Config.Store.maxInMemObjSize
6b698a21 4120DOC_START
41bd17a4 4121 Objects greater than this size will not be attempted to kept in
4122 the memory cache. This should be set high enough to keep objects
4123 accessed frequently in memory to improve performance whilst low
4124 enough to keep larger objects from hoarding cache_mem.
6b698a21 4125DOC_END
0976f8db 4126
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4127NAME: memory_cache_shared
4128COMMENT: on|off
4129TYPE: YesNoNone
4130LOC: Config.memShared
4131DEFAULT: none
70f856bc 4132DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
57af1e3f
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4133DOC_START
4134 Controls whether the memory cache is shared among SMP workers.
4135
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4136 The shared memory cache is meant to occupy cache_mem bytes and replace
4137 the non-shared memory cache, although some entities may still be
4138 cached locally by workers for now (e.g., internal and in-transit
4139 objects may be served from a local memory cache even if shared memory
4140 caching is enabled).
4141
65b81b27 4142 By default, the memory cache is shared if and only if all of the
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4143 following conditions are satisfied: Squid runs in SMP mode with
4144 multiple workers, cache_mem is positive, and Squid environment
4145 supports required IPC primitives (e.g., POSIX shared memory segments
4146 and GCC-style atomic operations).
4147
4148 To avoid blocking locks, shared memory uses opportunistic algorithms
4149 that do not guarantee that every cachable entity that could have been
4150 shared among SMP workers will actually be shared.
57af1e3f
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4151DOC_END
4152
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HN
4153NAME: memory_cache_mode
4154TYPE: memcachemode
4155LOC: Config
4156DEFAULT: always
638402dd 4157DEFAULT_DOC: Keep the most recently fetched objects in memory
ff4b33f4 4158DOC_START
ea21d497 4159 Controls which objects to keep in the memory cache (cache_mem)
ff4b33f4 4160
ea21d497
HN
4161 always Keep most recently fetched objects in memory (default)
4162
4163 disk Only disk cache hits are kept in memory, which means
4164 an object must first be cached on disk and then hit
4165 a second time before cached in memory.
4166
4167 network Only objects fetched from network is kept in memory
ff4b33f4
HN
4168DOC_END
4169
41bd17a4 4170NAME: memory_replacement_policy
4171TYPE: removalpolicy
4172LOC: Config.memPolicy
4173DEFAULT: lru
6b698a21 4174DOC_START
41bd17a4 4175 The memory replacement policy parameter determines which
4176 objects are purged from memory when memory space is needed.
7f7db318 4177
638402dd 4178 See cache_replacement_policy for details on algorithms.
41bd17a4 4179DOC_END
6b698a21 4180
41bd17a4 4181COMMENT_START
4182 DISK CACHE OPTIONS
4183 -----------------------------------------------------------------------------
4184COMMENT_END
6b698a21 4185
41bd17a4 4186NAME: cache_replacement_policy
4187TYPE: removalpolicy
4188LOC: Config.replPolicy
4189DEFAULT: lru
4190DOC_START
4191 The cache replacement policy parameter determines which
4192 objects are evicted (replaced) when disk space is needed.
6b698a21 4193
41bd17a4 4194 lru : Squid's original list based LRU policy
4195 heap GDSF : Greedy-Dual Size Frequency
4196 heap LFUDA: Least Frequently Used with Dynamic Aging
4197 heap LRU : LRU policy implemented using a heap
6b698a21 4198
638402dd 4199 Applies to any cache_dir lines listed below this directive.
7f7db318 4200
41bd17a4 4201 The LRU policies keeps recently referenced objects.
0976f8db 4202
41bd17a4 4203 The heap GDSF policy optimizes object hit rate by keeping smaller
4204 popular objects in cache so it has a better chance of getting a
4205 hit. It achieves a lower byte hit rate than LFUDA though since
4206 it evicts larger (possibly popular) objects.
0976f8db 4207
41bd17a4 4208 The heap LFUDA policy keeps popular objects in cache regardless of
4209 their size and thus optimizes byte hit rate at the expense of
4210 hit rate since one large, popular object will prevent many
4211 smaller, slightly less popular objects from being cached.
0976f8db 4212
41bd17a4 4213 Both policies utilize a dynamic aging mechanism that prevents
4214 cache pollution that can otherwise occur with frequency-based
4215 replacement policies.
7d90757b 4216
41bd17a4 4217 NOTE: if using the LFUDA replacement policy you should increase
b51ec8c8 4218 the value of maximum_object_size above its default of 4 MB to
41bd17a4 4219 to maximize the potential byte hit rate improvement of LFUDA.
dc1af3cf 4220
41bd17a4 4221 For more information about the GDSF and LFUDA cache replacement
4222 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
4223 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
6b698a21 4224DOC_END
0976f8db 4225
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AJ
4226NAME: minimum_object_size
4227COMMENT: (bytes)
4228TYPE: b_int64_t
4229DEFAULT: 0 KB
4230DEFAULT_DOC: no limit
4231LOC: Config.Store.minObjectSize
4232DOC_START
4233 Objects smaller than this size will NOT be saved on disk. The
4234 value is specified in bytes, and the default is 0 KB, which
4235 means all responses can be stored.
4236DOC_END
4237
4238NAME: maximum_object_size
4239COMMENT: (bytes)
4240TYPE: b_int64_t
4241DEFAULT: 4 MB
4242LOC: Config.Store.maxObjectSize
4243DOC_START
499f852c 4244 Set the default value for max-size parameter on any cache_dir.
a345387f 4245 The value is specified in bytes, and the default is 4 MB.
9603207d 4246
a345387f
AJ
4247 If you wish to get a high BYTES hit ratio, you should probably
4248 increase this (one 32 MB object hit counts for 3200 10KB
4249 hits).
9603207d 4250
a345387f
AJ
4251 If you wish to increase hit ratio more than you want to
4252 save bandwidth you should leave this low.
9603207d 4253
a345387f
AJ
4254 NOTE: if using the LFUDA replacement policy you should increase
4255 this value to maximize the byte hit rate improvement of LFUDA!
4256 See cache_replacement_policy for a discussion of this policy.
4257DOC_END
4258
41bd17a4 4259NAME: cache_dir
4260TYPE: cachedir
4261DEFAULT: none
2f8abb64 4262DEFAULT_DOC: No disk cache. Store cache objects only in memory.
41bd17a4 4263LOC: Config.cacheSwap
6b698a21 4264DOC_START
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AJ
4265 Format:
4266 cache_dir Type Directory-Name Fs-specific-data [options]
0976f8db 4267
41bd17a4 4268 You can specify multiple cache_dir lines to spread the
4269 cache among different disk partitions.
0976f8db 4270
41bd17a4 4271 Type specifies the kind of storage system to use. Only "ufs"
4272 is built by default. To enable any of the other storage systems
4273 see the --enable-storeio configure option.
0976f8db 4274
41bd17a4 4275 'Directory' is a top-level directory where cache swap
4276 files will be stored. If you want to use an entire disk
4277 for caching, this can be the mount-point directory.
4278 The directory must exist and be writable by the Squid
4279 process. Squid will NOT create this directory for you.
0976f8db 4280
acf69d74
AJ
4281 In SMP configurations, cache_dir must not precede the workers option
4282 and should use configuration macros or conditionals to give each
4283 worker interested in disk caching a dedicated cache directory.
4284
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4285
4286 ==== The ufs store type ====
0976f8db 4287
41bd17a4 4288 "ufs" is the old well-known Squid storage format that has always
4289 been there.
0976f8db 4290
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AJ
4291 Usage:
4292 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
0976f8db 4293
41bd17a4 4294 'Mbytes' is the amount of disk space (MB) to use under this
4295 directory. The default is 100 MB. Change this to suit your
4296 configuration. Do NOT put the size of your disk drive here.
4297 Instead, if you want Squid to use the entire disk drive,
4298 subtract 20% and use that value.
0976f8db 4299
56fba4d0 4300 'L1' is the number of first-level subdirectories which
41bd17a4 4301 will be created under the 'Directory'. The default is 16.
0976f8db 4302
56fba4d0 4303 'L2' is the number of second-level subdirectories which
41bd17a4 4304 will be created under each first-level directory. The default
4305 is 256.
0976f8db 4306
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AJ
4307
4308 ==== The aufs store type ====
7f7db318 4309
41bd17a4 4310 "aufs" uses the same storage format as "ufs", utilizing
4311 POSIX-threads to avoid blocking the main Squid process on
4312 disk-I/O. This was formerly known in Squid as async-io.
38f9c547 4313
638402dd
AJ
4314 Usage:
4315 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
38f9c547 4316
41bd17a4 4317 see argument descriptions under ufs above
38f9c547 4318
638402dd
AJ
4319
4320 ==== The diskd store type ====
38f9c547 4321
41bd17a4 4322 "diskd" uses the same storage format as "ufs", utilizing a
4323 separate process to avoid blocking the main Squid process on
4324 disk-I/O.
4c3ef9b2 4325
638402dd
AJ
4326 Usage:
4327 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
0976f8db 4328
41bd17a4 4329 see argument descriptions under ufs above
0976f8db 4330
41bd17a4 4331 Q1 specifies the number of unacknowledged I/O requests when Squid
4332 stops opening new files. If this many messages are in the queues,
4333 Squid won't open new files. Default is 64
0976f8db 4334
41bd17a4 4335 Q2 specifies the number of unacknowledged messages when Squid
4336 starts blocking. If this many messages are in the queues,
4337 Squid blocks until it receives some replies. Default is 72
0976f8db 4338
41bd17a4 4339 When Q1 < Q2 (the default), the cache directory is optimized
4340 for lower response time at the expense of a decrease in hit
4341 ratio. If Q1 > Q2, the cache directory is optimized for
4342 higher hit ratio at the expense of an increase in response
4343 time.
0976f8db 4344
e2851fe7 4345
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AJ
4346 ==== The rock store type ====
4347
4348 Usage:
e51ce7da 4349 cache_dir rock Directory-Name Mbytes [options]
e2851fe7 4350
2e55f083 4351 The Rock Store type is a database-style storage. All cached
e51ce7da
AR
4352 entries are stored in a "database" file, using fixed-size slots.
4353 A single entry occupies one or more slots.
e2851fe7 4354
3e1dfe3d
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4355 If possible, Squid using Rock Store creates a dedicated kid
4356 process called "disker" to avoid blocking Squid worker(s) on disk
4357 I/O. One disker kid is created for each rock cache_dir. Diskers
4358 are created only when Squid, running in daemon mode, has support
4359 for the IpcIo disk I/O module.
4360
43ebbac3
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4361 swap-timeout=msec: Squid will not start writing a miss to or
4362 reading a hit from disk if it estimates that the swap operation
4363 will take more than the specified number of milliseconds. By
4364 default and when set to zero, disables the disk I/O time limit
4365 enforcement. Ignored when using blocking I/O module because
4366 blocking synchronous I/O does not allow Squid to estimate the
4367 expected swap wait time.
4368
df881a0f 4369 max-swap-rate=swaps/sec: Artificially limits disk access using
1e614370 4370 the specified I/O rate limit. Swap out requests that
df881a0f 4371 would cause the average I/O rate to exceed the limit are
1e614370
DK
4372 delayed. Individual swap in requests (i.e., hits or reads) are
4373 not delayed, but they do contribute to measured swap rate and
4374 since they are placed in the same FIFO queue as swap out
4375 requests, they may wait longer if max-swap-rate is smaller.
4376 This is necessary on file systems that buffer "too
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4377 many" writes and then start blocking Squid and other processes
4378 while committing those writes to disk. Usually used together
4379 with swap-timeout to avoid excessive delays and queue overflows
4380 when disk demand exceeds available disk "bandwidth". By default
4381 and when set to zero, disables the disk I/O rate limit
4382 enforcement. Currently supported by IpcIo module only.
4383
e51ce7da
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4384 slot-size=bytes: The size of a database "record" used for
4385 storing cached responses. A cached response occupies at least
4386 one slot and all database I/O is done using individual slots so
4387 increasing this parameter leads to more disk space waste while
4388 decreasing it leads to more disk I/O overheads. Should be a
4389 multiple of your operating system I/O page size. Defaults to
4390 16KBytes. A housekeeping header is stored with each slot and
4391 smaller slot-sizes will be rejected. The header is smaller than
4392 100 bytes.
4393
df881a0f 4394
638402dd 4395 ==== COMMON OPTIONS ====
0976f8db 4396
638402dd
AJ
4397 no-store no new objects should be stored to this cache_dir.
4398
4399 min-size=n the minimum object size in bytes this cache_dir
4400 will accept. It's used to restrict a cache_dir
4401 to only store large objects (e.g. AUFS) while
4402 other stores are optimized for smaller objects
73656056 4403 (e.g. Rock).
638402dd 4404 Defaults to 0.
0976f8db 4405
638402dd
AJ
4406 max-size=n the maximum object size in bytes this cache_dir
4407 supports.
499f852c
A
4408 The value in maximum_object_size directive sets
4409 the default unless more specific details are
4410 available (ie a small store capacity).
b6662ffd 4411
41bd17a4 4412 Note: To make optimal use of the max-size limits you should order
638402dd 4413 the cache_dir lines with the smallest max-size value first.
0976f8db 4414
47f0eaea 4415CONFIG_START
e0855596
AJ
4416
4417# Uncomment and adjust the following to add a disk cache directory.
4418#cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
47f0eaea 4419CONFIG_END
6b698a21 4420DOC_END
0976f8db 4421
41bd17a4 4422NAME: store_dir_select_algorithm
4423TYPE: string
4424LOC: Config.store_dir_select_algorithm
4425DEFAULT: least-load
6b698a21 4426DOC_START
638402dd
AJ
4427 How Squid selects which cache_dir to use when the response
4428 object will fit into more than one.
4429
4430 Regardless of which algorithm is used the cache_dir min-size
4431 and max-size parameters are obeyed. As such they can affect
4432 the selection algorithm by limiting the set of considered
4433 cache_dir.
4434
4435 Algorithms:
4436
4437 least-load
4438
4439 This algorithm is suited to caches with similar cache_dir
4440 sizes and disk speeds.
4441
4442 The disk with the least I/O pending is selected.
4443 When there are multiple disks with the same I/O load ranking
4444 the cache_dir with most available capacity is selected.
4445
4446 When a mix of cache_dir sizes are configured the faster disks
4447 have a naturally lower I/O loading and larger disks have more
4448 capacity. So space used to store objects and data throughput
4449 may be very unbalanced towards larger disks.
4450
4451
4452 round-robin
4453
4454 This algorithm is suited to caches with unequal cache_dir
4455 disk sizes.
4456
4457 Each cache_dir is selected in a rotation. The next suitable
4458 cache_dir is used.
4459
4460 Available cache_dir capacity is only considered in relation
4461 to whether the object will fit and meets the min-size and
4462 max-size parameters.
4463
4464 Disk I/O loading is only considered to prevent overload on slow
4465 disks. This algorithm does not spread objects by size, so any
4466 I/O loading per-disk may appear very unbalanced and volatile.
4467
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AR
4468 If several cache_dirs use similar min-size, max-size, or other
4469 limits to to reject certain responses, then do not group such
4470 cache_dir lines together, to avoid round-robin selection bias
4471 towards the first cache_dir after the group. Instead, interleave
4472 cache_dir lines from different groups. For example:
4473
4474 store_dir_select_algorithm round-robin
4475 cache_dir rock /hdd1 ... min-size=100000
4476 cache_dir rock /ssd1 ... max-size=99999
4477 cache_dir rock /hdd2 ... min-size=100000
4478 cache_dir rock /ssd2 ... max-size=99999
4479 cache_dir rock /hdd3 ... min-size=100000
4480 cache_dir rock /ssd3 ... max-size=99999
6b698a21 4481DOC_END
0976f8db 4482
b2aca62a
EB
4483NAME: paranoid_hit_validation
4484COMMENT: time-units-small
4485TYPE: time_nanoseconds
4486DEFAULT: 0
4487DEFAULT_DOC: validation disabled
4488LOC: Config.paranoid_hit_validation
4489DOC_START
4490 Controls whether Squid should perform paranoid validation of cache entry
4491 metadata integrity every time a cache entry is hit. This low-level
4492 validation should always succeed. Each failed validation results in a
4493 cache miss, a BUG line reported to cache.log, and the invalid entry
4494 marked as unusable (and eventually purged from the cache).
4495
4496 Squid can only validate shared cache memory and rock cache_dir entries.
4497
4498 * Zero (default) value means that the validation is disabled.
4499
4500 * Positive values enable validation:
4501 - values less than 1 day approximate the maximum time that Squid is allowed
4502 to spend validating a single cache hit.
4503 - values greater or equal to 1 day are considered as no limitation:
4504 in this case all checks will be performed, regardless of how much time
4505 they take.
4506
4507 Hits are usually stored using 16KB slots (for rock, the size is
4508 configurable via cache_dir slot-size). Larger hits require scanning more
4509 slots and, hence, take more time. When validation is enabled, at least one
4510 slot is always validated, regardless of the configured time limit.
4511
4512 A worker process validating an entry cannot do anything else (i.e. the
4513 validation is blocking). The validation overhead is environment dependent,
4514 but developers have observed Squid spending 3-10 microseconds to check each
4515 slot of a Rock or shared memory hit entry. If Squid cuts validation short
4516 because it runs out of configured time, it treats the entry as valid.
4517
4518 When hit validation is enabled, its statistics is included in Cache
4519 Manager mgr:counters, mgr:5min, and mgr:60min reports.
4520DOC_END
4521
41bd17a4 4522NAME: max_open_disk_fds
4523TYPE: int
4524LOC: Config.max_open_disk_fds
4525DEFAULT: 0
638402dd 4526DEFAULT_DOC: no limit
6b698a21 4527DOC_START
41bd17a4 4528 To avoid having disk as the I/O bottleneck Squid can optionally
4529 bypass the on-disk cache if more than this amount of disk file
4530 descriptors are open.
4531
4532 A value of 0 indicates no limit.
6b698a21 4533DOC_END
0976f8db 4534
41bd17a4 4535NAME: cache_swap_low
4536COMMENT: (percent, 0-100)
5473c134 4537TYPE: int
41bd17a4 4538DEFAULT: 90
4539LOC: Config.Swap.lowWaterMark
638402dd 4540DOC_START
5f662601
AJ
4541 The low-water mark for AUFS/UFS/diskd cache object eviction by
4542 the cache_replacement_policy algorithm.
4543
4544 Removal begins when the swap (disk) usage of a cache_dir is
4545 above this low-water mark and attempts to maintain utilization
4546 near the low-water mark.
4547
4548 As swap utilization increases towards the high-water mark set
2f8abb64 4549 by cache_swap_high object eviction becomes more aggressive.
5f662601
AJ
4550
4551 The value difference in percentages between low- and high-water
7bcaf76f 4552 marks represent an eviction rate of 300 objects per second and
2f8abb64 4553 the rate continues to scale in aggressiveness by multiples of
5f662601 4554 this above the high-water mark.
638402dd
AJ
4555
4556 Defaults are 90% and 95%. If you have a large cache, 5% could be
4557 hundreds of MB. If this is the case you may wish to set these
4558 numbers closer together.
4559
5f662601 4560 See also cache_swap_high and cache_replacement_policy
638402dd 4561DOC_END
41bd17a4 4562
4563NAME: cache_swap_high
4564COMMENT: (percent, 0-100)
4565TYPE: int
4566DEFAULT: 95
4567LOC: Config.Swap.highWaterMark
6b698a21 4568DOC_START
5f662601
AJ
4569 The high-water mark for AUFS/UFS/diskd cache object eviction by
4570 the cache_replacement_policy algorithm.
4571
4572 Removal begins when the swap (disk) usage of a cache_dir is
4573 above the low-water mark set by cache_swap_low and attempts to
4574 maintain utilization near the low-water mark.
4575
4576 As swap utilization increases towards this high-water mark object
2f8abb64 4577 eviction becomes more aggressive.
5f662601
AJ
4578
4579 The value difference in percentages between low- and high-water
7bcaf76f 4580 marks represent an eviction rate of 300 objects per second and
2f8abb64 4581 the rate continues to scale in aggressiveness by multiples of
5f662601 4582 this above the high-water mark.
41bd17a4 4583
4584 Defaults are 90% and 95%. If you have a large cache, 5% could be
4585 hundreds of MB. If this is the case you may wish to set these
4586 numbers closer together.
638402dd 4587
5f662601 4588 See also cache_swap_low and cache_replacement_policy
6b698a21 4589DOC_END
0976f8db 4590
5473c134 4591COMMENT_START
41bd17a4 4592 LOGFILE OPTIONS
5473c134 4593 -----------------------------------------------------------------------------
4594COMMENT_END
0976f8db 4595
41bd17a4 4596NAME: logformat
4597TYPE: logformat
20efa1c2 4598LOC: Log::TheConfig
5473c134 4599DEFAULT: none
638402dd 4600DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
6b698a21 4601DOC_START
41bd17a4 4602 Usage:
0976f8db 4603
41bd17a4 4604 logformat <name> <format specification>
0976f8db 4605
41bd17a4 4606 Defines an access log format.
6b698a21 4607
41bd17a4 4608 The <format specification> is a string with embedded % format codes
5473c134 4609
bec110e4
EB
4610 % format codes all follow the same basic structure where all
4611 components but the formatcode are optional and usually unnecessary,
4612 especially when dealing with common codes.
6b698a21 4613
bec110e4 4614 % [encoding] [-] [[0]width] [{arg}] formatcode [{arg}]
0976f8db 4615
bec110e4
EB
4616 encoding escapes or otherwise protects "special" characters:
4617
4618 " Quoted string encoding where quote(") and
4619 backslash(\) characters are \-escaped while
4620 CR, LF, and TAB characters are encoded as \r,
4621 \n, and \t two-character sequences.
4622
4623 [ Custom Squid encoding where percent(%), square
4624 brackets([]), backslash(\) and characters with
4625 codes outside of [32,126] range are %-encoded.
4626 SP is not encoded. Used by log_mime_hdrs.
4627
4628 # URL encoding (a.k.a. percent-encoding) where
4629 all URL unsafe and control characters (per RFC
4630 1738) are %-encoded.
4631
4632 / Shell-like encoding where quote(") and
4633 backslash(\) characters are \-escaped while CR
4634 and LF characters are encoded as \r and \n
4635 two-character sequences. Values containing SP
4636 character(s) are surrounded by quotes(").
4637
4638 ' Raw/as-is encoding with no escaping/quoting.
4639
4640 Default encoding: When no explicit encoding is
4641 specified, each %code determines its own encoding.
4642 Most %codes use raw/as-is encoding, but some codes use
4643 a so called "pass-through URL encoding" where all URL
4644 unsafe and control characters (per RFC 1738) are
4645 %-encoded, but the percent character(%) is left as is.
5473c134 4646
41bd17a4 4647 - left aligned
c32c6db7
AR
4648
4649 width minimum and/or maximum field width:
4650 [width_min][.width_max]
e2851fe7
AR
4651 When minimum starts with 0, the field is zero-padded.
4652 String values exceeding maximum width are truncated.
c32c6db7 4653
4e56d7f6
AJ
4654 {arg} argument such as header name etc. This field may be
4655 placed before or after the token, but not both at once.
5473c134 4656
41bd17a4 4657 Format codes:
5473c134 4658
3ff65596 4659 % a literal % character
f4b68e1a
AJ
4660 sn Unique sequence number per log line entry
4661 err_code The ID of an error response served by Squid or
4662 a similar internal error identifier.
4663 err_detail Additional err_code-dependent error information.
c7bcf010 4664 note The annotation specified by the argument. Also
d7f4a0b7
CT
4665 logs the adaptation meta headers set by the
4666 adaptation_meta configuration parameter.
c7bcf010
CT
4667 If no argument given all annotations logged.
4668 The argument may include a separator to use with
4669 annotation values:
4670 name[:separator]
4671 By default, multiple note values are separated with ","
4672 and multiple notes are separated with "\r\n".
4673 When logging named notes with %{name}note, the
4674 explicitly configured separator is used between note
4675 values. When logging all notes with %note, the
4676 explicitly configured separator is used between
4677 individual notes. There is currently no way to
4678 specify both value and notes separators when logging
4679 all notes with %note.
7cfd3a41
EB
4680 master_xaction The master transaction identifier is an unsigned
4681 integer. These IDs are guaranteed to monotonically
4682 increase within a single worker process lifetime, with
4683 higher values corresponding to transactions that were
4684 accepted or initiated later. Due to current implementation
4685 deficiencies, some IDs are skipped (i.e. never logged).
4686 Concurrent workers and restarted workers use similar,
4687 overlapping sequences of master transaction IDs.
f4b68e1a
AJ
4688
4689 Connection related format codes:
4690
41bd17a4 4691 >a Client source IP address
4692 >A Client FQDN
4693 >p Client source port
8652f8e7
AJ
4694 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
4695 >la Local IP address the client connected to
4696 >lp Local port number the client connected to
f123f5e9 4697 >qos Client connection TOS/DSCP value set by Squid
244da4ad 4698 >nfmark Client connection netfilter packet MARK set by Squid
8652f8e7 4699
a120b7a8
CT
4700 transport::>connection_id Identifies a transport connection
4701 accepted by Squid (e.g., a connection carrying the
4702 logged HTTP request). Currently, Squid only supports
4703 TCP transport connections.
4704
4705 The logged identifier is an unsigned integer. These
4706 IDs are guaranteed to monotonically increase within a
4707 single worker process lifetime, with higher values
4708 corresponding to connections that were accepted later.
4709 Many IDs are skipped (i.e. never logged). Concurrent
4710 workers and restarted workers use similar, partially
4711 overlapping sequences of IDs.
4712
28417506
CT
4713 la Local listening IP address the client connection was connected to.
4714 lp Local listening port number the client connection was connected to.
4715
8652f8e7
AJ
4716 <a Server IP address of the last server or peer connection
4717 <A Server FQDN or peer name
4718 <p Server port number of the last server or peer connection
c3a082ae 4719 <la Local IP address of the last server or peer connection
152e24b3 4720 <lp Local port number of the last server or peer connection
f123f5e9 4721 <qos Server connection TOS/DSCP value set by Squid
244da4ad 4722 <nfmark Server connection netfilter packet MARK set by Squid
f4b68e1a 4723
6131103b
CT
4724 >handshake Raw client handshake
4725 Initial client bytes received by Squid on a newly
4726 accepted TCP connection or inside a just established
4727 CONNECT tunnel. Squid stops accumulating handshake
4728 bytes as soon as the handshake parser succeeds or
4729 fails (determining whether the client is using the
4730 expected protocol).
4731
4732 For HTTP clients, the handshake is the request line.
4733 For TLS clients, the handshake consists of all TLS
4734 records up to and including the TLS record that
4735 contains the last byte of the first ClientHello
4736 message. For clients using an unsupported protocol,
4737 this field contains the bytes received by Squid at the
4738 time of the handshake parsing failure.
4739
4740 See the on_unsupported_protocol directive for more
4741 information on Squid handshake traffic expectations.
4742
4743 Current support is limited to these contexts:
4744 - http_port connections, but only when the
4745 on_unsupported_protocol directive is in use.
4746 - https_port connections (and CONNECT tunnels) that
4747 are subject to the ssl_bump peek or stare action.
4748
4749 To protect binary handshake data, this field is always
4750 base64-encoded (RFC 4648 Section 4). If logformat
4751 field encoding is configured, that encoding is applied
4752 on top of base64. Otherwise, the computed base64 value
4753 is recorded as is.
4754
f4b68e1a
AJ
4755 Time related format codes:
4756
41bd17a4 4757 ts Seconds since epoch
4758 tu subsecond time (milliseconds)
4759 tl Local time. Optional strftime format argument
3ff65596 4760 default %d/%b/%Y:%H:%M:%S %z
41bd17a4 4761 tg GMT time. Optional strftime format argument
3ff65596 4762 default %d/%b/%Y:%H:%M:%S %z
41bd17a4 4763 tr Response time (milliseconds)
3ff65596 4764 dt Total time spent making DNS lookups (milliseconds)
9603207d 4765 tS Approximate master transaction start time in
af0ded40
CT
4766 <full seconds since epoch>.<fractional seconds> format.
4767 Currently, Squid considers the master transaction
4768 started when a complete HTTP request header initiating
4769 the transaction is received from the client. This is
4770 the same value that Squid uses to calculate transaction
4771 response time when logging %tr to access.log. Currently,
4772 Squid uses millisecond resolution for %tS values,
4773 similar to the default access.log "current time" field
4774 (%ts.%03tu).
3ff65596 4775
8652f8e7
AJ
4776 Access Control related format codes:
4777
4778 et Tag returned by external acl
4779 ea Log string returned by external acl
4780 un User name (any available)
4781 ul User name from authentication
4782 ue User name from external acl helper
4783 ui User name from ident
50b5c983
AJ
4784 un A user name. Expands to the first available name
4785 from the following list of information sources:
4786 - authenticated user name, like %ul
4787 - user name supplied by an external ACL, like %ue
4788 - SSL client name, like %us
4789 - ident user name, like %ui
d4806c91
CT
4790 credentials Client credentials. The exact meaning depends on
4791 the authentication scheme: For Basic authentication,
4792 it is the password; for Digest, the realm sent by the
4793 client; for NTLM and Negotiate, the client challenge
4794 or client credentials prefixed with "YR " or "KK ".
8652f8e7
AJ
4795
4796 HTTP related format codes:
3ff65596 4797
d6df21d2
AJ
4798 REQUEST
4799
4800 [http::]rm Request method (GET/POST etc)
4801 [http::]>rm Request method from client
4802 [http::]<rm Request method sent to server or peer
bec110e4
EB
4803
4804 [http::]ru Request URL received (or computed) and sanitized
4805
4806 Logs request URI received from the client, a
4807 request adaptation service, or a request
4808 redirector (whichever was applied last).
4809
4810 Computed URLs are URIs of internally generated
4811 requests and various "error:..." URIs.
4812
4813 Honors strip_query_terms and uri_whitespace.
4814
4815 This field is not encoded by default. Encoding
4816 this field using variants of %-encoding will
4817 clash with uri_whitespace modifications that
4818 also use %-encoding.
4819
4820 [http::]>ru Request URL received from the client (or computed)
4821
4822 Computed URLs are URIs of internally generated
4823 requests and various "error:..." URIs.
4824
4825 Unlike %ru, this request URI is not affected
4826 by request adaptation, URL rewriting services,
4827 and strip_query_terms.
4828
4829 Honors uri_whitespace.
4830
4831 This field is using pass-through URL encoding
4832 by default. Encoding this field using other
4833 variants of %-encoding will clash with
4834 uri_whitespace modifications that also use
4835 %-encoding.
4836
d6df21d2 4837 [http::]<ru Request URL sent to server or peer
5aca9cf2
AJ
4838 [http::]>rs Request URL scheme from client
4839 [http::]<rs Request URL scheme sent to server or peer
fa450988 4840 [http::]>rd Request URL domain from client
f42ac6e6 4841 [http::]<rd Request URL domain sent to server or peer
5aca9cf2
AJ
4842 [http::]>rP Request URL port from client
4843 [http::]<rP Request URL port sent to server or peer
4844 [http::]rp Request URL path excluding hostname
4845 [http::]>rp Request URL path excluding hostname from client
4846 [http::]<rp Request URL path excluding hostname sent to server or peer
d6df21d2
AJ
4847 [http::]rv Request protocol version
4848 [http::]>rv Request protocol version from client
4849 [http::]<rv Request protocol version sent to server or peer
4850
5aca9cf2 4851 [http::]>h Original received request header.
19483c50
AR
4852 Usually differs from the request header sent by
4853 Squid, although most fields are often preserved.
4854 Accepts optional header field name/value filter
4855 argument using name[:[separator]element] format.
4856 [http::]>ha Received request header after adaptation and
4857 redirection (pre-cache REQMOD vectoring point).
4858 Usually differs from the request header sent by
4859 Squid, although most fields are often preserved.
6fca33e0 4860 Optional header name argument as for >h
d6df21d2 4861
d6df21d2
AJ
4862 RESPONSE
4863
4864 [http::]<Hs HTTP status code received from the next hop
4865 [http::]>Hs HTTP status code sent to the client
4866
3ff65596
AR
4867 [http::]<h Reply header. Optional header name argument
4868 as for >h
d6df21d2
AJ
4869
4870 [http::]mt MIME content type
4871
4872
4873 SIZE COUNTERS
4874
4875 [http::]st Total size of request + reply traffic with client
4876 [http::]>st Total size of request received from client.
4877 Excluding chunked encoding bytes.
4878 [http::]<st Total size of reply sent to client (after adaptation)
4879
4880 [http::]>sh Size of request headers received from client
4881 [http::]<sh Size of reply headers sent to client (after adaptation)
4882
4883 [http::]<sH Reply high offset sent
4884 [http::]<sS Upstream object size
4885
9603207d 4886 [http::]<bs Number of HTTP-equivalent message body bytes
bae917ac
CT
4887 received from the next hop, excluding chunked
4888 transfer encoding and control messages.
6ea12e8f 4889 Generated FTP listings are treated as
bae917ac 4890 received bodies.
d6df21d2 4891
d6df21d2
AJ
4892 TIMING
4893
3ff65596
AR
4894 [http::]<pt Peer response time in milliseconds. The timer starts
4895 when the last request byte is sent to the next hop
4896 and stops when the last response byte is received.
9603207d 4897 [http::]<tt Total time in milliseconds. The timer
3ff65596
AR
4898 starts with the first connect request (or write I/O)
4899 sent to the first selected peer. The timer stops
4900 with the last I/O with the last peer.
4901
8652f8e7
AJ
4902 Squid handling related format codes:
4903
4904 Ss Squid request status (TCP_MISS etc)
4905 Sh Squid hierarchy status (DEFAULT_PARENT etc)
4906
08097970
AR
4907 SSL-related format codes:
4908
4909 ssl::bump_mode SslBump decision for the transaction:
4910
4911 For CONNECT requests that initiated bumping of
4912 a connection and for any request received on
4913 an already bumped connection, Squid logs the
bf352fb2
CT
4914 corresponding SslBump mode ("splice", "bump",
4915 "peek", "stare", "terminate", "server-first"
9603207d 4916 or "client-first"). See the ssl_bump option
bf352fb2 4917 for more information about these modes.
08097970
AR
4918
4919 A "none" token is logged for requests that
4920 triggered "ssl_bump" ACL evaluation matching
bf352fb2 4921 a "none" rule.
08097970
AR
4922
4923 In all other cases, a single dash ("-") is
4924 logged.
4925
4f6990ec 4926 ssl::>sni SSL client SNI sent to Squid.
cedca6e7 4927
c28b9a0e
AJ
4928 ssl::>cert_subject
4929 The Subject field of the received client
4930 SSL certificate or a dash ('-') if Squid has
4931 received an invalid/malformed certificate or
4932 no certificate at all. Consider encoding the
4933 logged value because Subject often has spaces.
4934
4935 ssl::>cert_issuer
4936 The Issuer field of the received client
4937 SSL certificate or a dash ('-') if Squid has
4938 received an invalid/malformed certificate or
4939 no certificate at all. Consider encoding the
4940 logged value because Issuer often has spaces.
4941
e2e33acc
CT
4942 ssl::<cert_subject
4943 The Subject field of the received server
4944 TLS certificate or a dash ('-') if this is
4945 not available. Consider encoding the logged
4946 value because Subject often has spaces.
4947
8f1c6091 4948 ssl::<cert_issuer
e2e33acc
CT
4949 The Issuer field of the received server
4950 TLS certificate or a dash ('-') if this is
4951 not available. Consider encoding the logged
4952 value because Issuer often has spaces.
4953
12b5040f
DN
4954 ssl::<cert
4955 The received server x509 certificate in PEM
4956 format, including BEGIN and END lines (or a
4957 dash ('-') if the certificate is unavailable).
4958
4959 WARNING: Large certificates will exceed the
4960 current 8KB access.log record limit, resulting
4961 in truncated records. Such truncation usually
4962 happens in the middle of a record field. The
4963 limit applies to all access logging modules.
4964
4965 The logged certificate may have failed
4966 validation and may not be trusted by Squid.
4967 This field does not include any intermediate
4968 certificates that may have been received from
4969 the server or fetched during certificate
4970 validation process.
4971
4972 Currently, Squid only collects server
4973 certificates during step3 of SslBump
4974 processing; connections that were not subject
4975 to ssl_bump rules or that did not match a peek
4976 or stare rule at step2 will not have the
4977 server certificate information.
4978
4979 This field is using pass-through URL encoding
4980 by default.
4981
c28b9a0e
AJ
4982 ssl::<cert_errors
4983 The list of certificate validation errors
4984 detected by Squid (including OpenSSL and
4985 certificate validation helper components). The
4986 errors are listed in the discovery order. By
4987 default, the error codes are separated by ':'.
4988 Accepts an optional separator argument.
4989
2bcab852
CT
4990 %ssl::>negotiated_version The negotiated TLS version of the
4991 client connection.
4992
4993 %ssl::<negotiated_version The negotiated TLS version of the
4994 last server or peer connection.
4995
4996 %ssl::>received_hello_version The TLS version of the Hello
4997 message received from TLS client.
4998
4999 %ssl::<received_hello_version The TLS version of the Hello
5000 message received from TLS server.
5001
5002 %ssl::>received_supported_version The maximum TLS version
5003 supported by the TLS client.
5004
5005 %ssl::<received_supported_version The maximum TLS version
5006 supported by the TLS server.
5007
5008 %ssl::>negotiated_cipher The negotiated cipher of the
5009 client connection.
5010
5011 %ssl::<negotiated_cipher The negotiated cipher of the
5012 last server or peer connection.
5013
5038f9d8 5014 If ICAP is enabled, the following code becomes available (as
3ff65596
AR
5015 well as ICAP log codes documented with the icap_log option):
5016
40dc90df
AR
5017 icap::tt Total ICAP "blocking" time for the HTTP transaction. The
5018 timer ticks while Squid checks adaptation_access and while
5019 ICAP transaction(s) expect ICAP response headers, including
5020 the embedded adapted HTTP message headers (where applicable).
5021 This measurement is meant to estimate ICAP impact on HTTP
5022 transaction response times, but it does not currently account
5023 for slow ICAP response body delivery blocking HTTP progress.
5024
5025 Once Squid receives the final ICAP response headers (e.g.,
5026 ICAP 200 or 204) and the associated adapted HTTP message
5027 headers (if any) from the ICAP service, the corresponding ICAP
5028 transaction stops affecting this measurement, even though the
5029 transaction itself may continue for a long time (e.g., to
5030 finish sending the ICAP request and/or to finish receiving the
5031 ICAP response body).
5032
5033 When "blocking" sections of multiple concurrent ICAP
5034 transactions overlap in time, the overlapping segment is
5035 counted only once.
5036
5037 To see complete ICAP transaction response times (rather than
5038 the cumulative effect of their blocking sections) use the
5039 %adapt::all_trs logformat code or the icap_log directive.
3ff65596 5040
c28b9a0e 5041 If adaptation is enabled the following codes become available:
3ff65596 5042
5038f9d8
AR
5043 adapt::<last_h The header of the last ICAP response or
5044 meta-information from the last eCAP
5045 transaction related to the HTTP transaction.
5046 Like <h, accepts an optional header name
5047 argument.
3ff65596
AR
5048
5049 adapt::sum_trs Summed adaptation transaction response
5050 times recorded as a comma-separated list in
5051 the order of transaction start time. Each time
5052 value is recorded as an integer number,
5053 representing response time of one or more
5054 adaptation (ICAP or eCAP) transaction in
5055 milliseconds. When a failed transaction is
5056 being retried or repeated, its time is not
5057 logged individually but added to the
40dc90df
AR
5058 replacement (next) transaction. Lifetimes of individually
5059 listed adaptation transactions may overlap.
5060 See also: %icap::tt and %adapt::all_trs.
3ff65596
AR
5061
5062 adapt::all_trs All adaptation transaction response times.
40dc90df 5063 Same as %adapt::sum_trs but response times of
3ff65596
AR
5064 individual transactions are never added
5065 together. Instead, all transaction response
5066 times are recorded individually.
5067
5068 You can prefix adapt::*_trs format codes with adaptation
5069 service name in curly braces to record response time(s) specific
5070 to that service. For example: %{my_service}adapt::sum_trs
5473c134 5071
36c774f7
EB
5072 Format codes related to the PROXY protocol:
5073
5074 proxy_protocol::>h PROXY protocol header, including optional TLVs.
5075
5076 Supports the same field and element reporting/extraction logic
5077 as %http::>h. For configuration and reporting purposes, Squid
5078 maps each PROXY TLV to an HTTP header field: the TLV type
5079 (configured as a decimal integer) is the field name, and the
5080 TLV value is the field value. All TLVs of "LOCAL" connections
5081 (in PROXY protocol terminology) are currently skipped/ignored.
5082
5083 Squid also maps the following standard PROXY protocol header
5084 blocks to pseudo HTTP headers (their names use PROXY
5085 terminology and start with a colon, following HTTP tradition
5086 for pseudo headers): :command, :version, :src_addr, :dst_addr,
5087 :src_port, and :dst_port.
5088
5089 Without optional parameters, this logformat code logs
5090 pseudo headers and TLVs.
5091
5092 This format code uses pass-through URL encoding by default.
5093
5094 Example:
5095 # relay custom PROXY TLV #224 to adaptation services
5096 adaptation_meta Client-Foo "%proxy_protocol::>h{224}"
5097
5098 See also: %http::>h
5099
7d9acc3c
AJ
5100 The default formats available (which do not need re-defining) are:
5101
bd85ea1f
AJ
5102logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
5103logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
5104logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
20efa1c2
AJ
5105logformat referrer %ts.%03tu %>a %{Referer}>h %ru
5106logformat useragent %>a [%tl] "%{User-Agent}>h"
5107
8652f8e7
AJ
5108 NOTE: When the log_mime_hdrs directive is set to ON.
5109 The squid, common and combined formats have a safely encoded copy
5110 of the mime headers appended to each line within a pair of brackets.
5111
5112 NOTE: The common and combined formats are not quite true to the Apache definition.
5113 The logs from Squid contain an extra status and hierarchy code appended.
20efa1c2 5114
5473c134 5115DOC_END
5116
41bd17a4 5117NAME: access_log cache_access_log
5118TYPE: access_log
5119LOC: Config.Log.accesslogs
82b7abe3 5120DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
5473c134 5121DOC_START
fb0c2f17 5122 Configures whether and how Squid logs HTTP and ICP transactions.
9603207d 5123 If access logging is enabled, a single line is logged for every
fb0c2f17
NH
5124 matching HTTP or ICP request. The recommended directive formats are:
5125
5126 access_log <module>:<place> [option ...] [acl acl ...]
5127 access_log none [acl acl ...]
5128
5129 The following directive format is accepted but may be deprecated:
82b7abe3 5130 access_log <module>:<place> [<logformat name> [acl acl ...]]
fb0c2f17
NH
5131
5132 In most cases, the first ACL name must not contain the '=' character
5133 and should not be equal to an existing logformat name. You can always
5134 start with an 'all' ACL to work around those restrictions.
9603207d 5135
82b7abe3 5136 Will log to the specified module:place using the specified format (which
41bd17a4 5137 must be defined in a logformat directive) those entries which match
5138 ALL the acl's specified (which must be defined in acl clauses).
82b7abe3 5139 If no acl is specified, all requests will be logged to this destination.
9603207d 5140
fb0c2f17
NH
5141 ===== Available options for the recommended directive format =====
5142
5143 logformat=name Names log line format (either built-in or
5144 defined by a logformat directive). Defaults
5145 to 'squid'.
5146
5147 buffer-size=64KB Defines approximate buffering limit for log
5148 records (see buffered_logs). Squid should not
5149 keep more than the specified size and, hence,
5150 should flush records before the buffer becomes
5151 full to avoid overflows under normal
5152 conditions (the exact flushing algorithm is
5153 module-dependent though). The on-error option
5154 controls overflow handling.
5155
5156 on-error=die|drop Defines action on unrecoverable errors. The
5157 'drop' action ignores (i.e., does not log)
5158 affected log records. The default 'die' action
9603207d 5159 kills the affected worker. The drop action
fb0c2f17
NH
5160 support has not been tested for modules other
5161 than tcp.
5162
efc23871
AJ
5163 rotate=N Specifies the number of log file rotations to
5164 make when you run 'squid -k rotate'. The default
5165 is to obey the logfile_rotate directive. Setting
5166 rotate=0 will disable the file name rotation,
5167 but the log files are still closed and re-opened.
5168 This will enable you to rename the logfiles
5169 yourself just before sending the rotate signal.
5170 Only supported by the stdio module.
5171
82b7abe3 5172 ===== Modules Currently available =====
9603207d 5173
bb7a1781 5174 none Do not log any requests matching these ACL.
82b7abe3 5175 Do not specify Place or logformat name.
9603207d 5176
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AJ
5177 stdio Write each log line to disk immediately at the completion of
5178 each request.
5179 Place: the filename and path to be written.
9603207d 5180
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5181 daemon Very similar to stdio. But instead of writing to disk the log
5182 line is passed to a daemon helper for asychronous handling instead.
5183 Place: varies depending on the daemon.
9603207d 5184
82b7abe3 5185 log_file_daemon Place: the file name and path to be written.
9603207d 5186
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5187 syslog To log each request via syslog facility.
5188 Place: The syslog facility and priority level for these entries.
5189 Place Format: facility.priority
5473c134 5190
82b7abe3
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5191 where facility could be any of:
5192 authpriv, daemon, local0 ... local7 or user.
5473c134 5193
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5194 And priority could be any of:
5195 err, warning, notice, info, debug.
9603207d 5196
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5197 udp To send each log line as text data to a UDP receiver.
5198 Place: The destination host name or IP and port.
f4fc8610 5199 Place Format: //host:port
df2eec10 5200
2bf4e8fa 5201 tcp To send each log line as text data to a TCP receiver.
fb0c2f17 5202 Lines may be accumulated before sending (see buffered_logs).
2bf4e8fa 5203 Place: The destination host name or IP and port.
f4fc8610 5204 Place Format: //host:port
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5205
5206 Default:
82b7abe3 5207 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
41bd17a4 5208DOC_END
5473c134 5209
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5210NAME: icap_log
5211TYPE: access_log
5212IFDEF: ICAP_CLIENT
5213LOC: Config.Log.icaplogs
5214DEFAULT: none
5215DOC_START
5216 ICAP log files record ICAP transaction summaries, one line per
5217 transaction.
5218
5219 The icap_log option format is:
5220 icap_log <filepath> [<logformat name> [acl acl ...]]
5221 icap_log none [acl acl ...]]
9603207d 5222
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5223 Please see access_log option documentation for details. The two
5224 kinds of logs share the overall configuration approach and many
5225 features.
5226
5227 ICAP processing of a single HTTP message or transaction may
5228 require multiple ICAP transactions. In such cases, multiple
5229 ICAP transaction log lines will correspond to a single access
5230 log line.
5231
bd59d61c
EB
5232 ICAP log supports many access.log logformat %codes. In ICAP context,
5233 HTTP message-related %codes are applied to the HTTP message embedded
5234 in an ICAP message. Logformat "%http::>..." codes are used for HTTP
5235 messages embedded in ICAP requests while "%http::<..." codes are used
5236 for HTTP messages embedded in ICAP responses. For example:
5237
5238 http::>h To-be-adapted HTTP message headers sent by Squid to
5239 the ICAP service. For REQMOD transactions, these are
5240 HTTP request headers. For RESPMOD, these are HTTP
5241 response headers, but Squid currently cannot log them
5242 (i.e., %http::>h will expand to "-" for RESPMOD).
5243
5244 http::<h Adapted HTTP message headers sent by the ICAP
5245 service to Squid (i.e., HTTP request headers in regular
5246 REQMOD; HTTP response headers in RESPMOD and during
5247 request satisfaction in REQMOD).
5248
5249 ICAP OPTIONS transactions do not embed HTTP messages.
5250
5251 Several logformat codes below deal with ICAP message bodies. An ICAP
5252 message body, if any, typically includes a complete HTTP message
5253 (required HTTP headers plus optional HTTP message body). When
5254 computing HTTP message body size for these logformat codes, Squid
5255 either includes or excludes chunked encoding overheads; see
5256 code-specific documentation for details.
5257
5258 For Secure ICAP services, all size-related information is currently
5259 computed before/after TLS encryption/decryption, as if TLS was not
5260 in use at all.
3ff65596
AR
5261
5262 The following format codes are also available for ICAP logs:
5263
5264 icap::<A ICAP server IP address. Similar to <A.
5265
5266 icap::<service_name ICAP service name from the icap_service
5267 option in Squid configuration file.
5268
5269 icap::ru ICAP Request-URI. Similar to ru.
5270
9603207d 5271 icap::rm ICAP request method (REQMOD, RESPMOD, or
3ff65596
AR
5272 OPTIONS). Similar to existing rm.
5273
bd59d61c
EB
5274 icap::>st The total size of the ICAP request sent to the ICAP
5275 server (ICAP headers + ICAP body), including chunking
5276 metadata (if any).
3ff65596 5277
bd59d61c
EB
5278 icap::<st The total size of the ICAP response received from the
5279 ICAP server (ICAP headers + ICAP body), including
5280 chunking metadata (if any).
3ff65596 5281
bd59d61c
EB
5282 icap::<bs The size of the ICAP response body received from the
5283 ICAP server, excluding chunking metadata (if any).
bae917ac 5284
3ff65596
AR
5285 icap::tr Transaction response time (in
5286 milliseconds). The timer starts when
5287 the ICAP transaction is created and
5288 stops when the transaction is completed.
5289 Similar to tr.
5290
5291 icap::tio Transaction I/O time (in milliseconds). The
5292 timer starts when the first ICAP request
5293 byte is scheduled for sending. The timers
5294 stops when the last byte of the ICAP response
5295 is received.
5296
5297 icap::to Transaction outcome: ICAP_ERR* for all
5298 transaction errors, ICAP_OPT for OPTION
5299 transactions, ICAP_ECHO for 204
5300 responses, ICAP_MOD for message
5301 modification, and ICAP_SAT for request
5302 satisfaction. Similar to Ss.
5303
5304 icap::Hs ICAP response status code. Similar to Hs.
5305
5306 icap::>h ICAP request header(s). Similar to >h.
5307
5308 icap::<h ICAP response header(s). Similar to <h.
5309
5310 The default ICAP log format, which can be used without an explicit
5311 definition, is called icap_squid:
5312
bd59d61c 5313logformat icap_squid %ts.%03tu %6icap::tr %>A %icap::to/%03icap::Hs %icap::<st %icap::rm %icap::ru %un -/%icap::<A -
3ff65596 5314
bd59d61c 5315 See also: logformat and %adapt::<last_h
3ff65596
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5316DOC_END
5317
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AJ
5318NAME: logfile_daemon
5319TYPE: string
5320DEFAULT: @DEFAULT_LOGFILED@
5321LOC: Log::TheConfig.logfile_daemon
5322DOC_START
5323 Specify the path to the logfile-writing daemon. This daemon is
5324 used to write the access and store logs, if configured.
14b24caf
HN
5325
5326 Squid sends a number of commands to the log daemon:
5327 L<data>\n - logfile data
5328 R\n - rotate file
5329 T\n - truncate file
dd68402f 5330 O\n - reopen file
14b24caf
HN
5331 F\n - flush file
5332 r<n>\n - set rotate count to <n>
5333 b<n>\n - 1 = buffer output, 0 = don't buffer output
5334
5335 No responses is expected.
82b7abe3
AJ
5336DOC_END
5337
8ebad780 5338NAME: stats_collection
3ff65596 5339TYPE: acl_access
8ebad780 5340LOC: Config.accessList.stats_collection
3ff65596 5341DEFAULT: none
638402dd 5342DEFAULT_DOC: Allow logging for all transactions.
5b0f5383 5343COMMENT: allow|deny acl acl...
3ff65596 5344DOC_START
8ebad780
CT
5345 This options allows you to control which requests gets accounted
5346 in performance counters.
b3567eb5
FC
5347
5348 This clause only supports fast acl types.
5349 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3ff65596
AR
5350DOC_END
5351
41bd17a4 5352NAME: cache_store_log
5353TYPE: string
df2eec10 5354DEFAULT: none
41bd17a4 5355LOC: Config.Log.store
5356DOC_START
5357 Logs the activities of the storage manager. Shows which
5358 objects are ejected from the cache, and which objects are
6d1dfcfc 5359 saved and for how long.
df2eec10 5360 There are not really utilities to analyze this data, so you can safely
6d1dfcfc 5361 disable it (the default).
9603207d 5362
6d1dfcfc
AJ
5363 Store log uses modular logging outputs. See access_log for the list
5364 of modules supported.
9603207d 5365
e0855596 5366 Example:
6d1dfcfc
AJ
5367 cache_store_log stdio:@DEFAULT_STORE_LOG@
5368 cache_store_log daemon:@DEFAULT_STORE_LOG@
5473c134 5369DOC_END
5370
41bd17a4 5371NAME: cache_swap_state cache_swap_log
5372TYPE: string
5373LOC: Config.Log.swap
5473c134 5374DEFAULT: none
638402dd 5375DEFAULT_DOC: Store the journal inside its cache_dir
5473c134 5376DOC_START
41bd17a4 5377 Location for the cache "swap.state" file. This index file holds
5378 the metadata of objects saved on disk. It is used to rebuild
5379 the cache during startup. Normally this file resides in each
5380 'cache_dir' directory, but you may specify an alternate
5381 pathname here. Note you must give a full filename, not just
5382 a directory. Since this is the index for the whole object
5383 list you CANNOT periodically rotate it!
5473c134 5384
41bd17a4 5385 If %s can be used in the file name it will be replaced with a
5386 a representation of the cache_dir name where each / is replaced
5387 with '.'. This is needed to allow adding/removing cache_dir
5388 lines when cache_swap_log is being used.
5473c134 5389
41bd17a4 5390 If have more than one 'cache_dir', and %s is not used in the name
5391 these swap logs will have names such as:
5473c134 5392
41bd17a4 5393 cache_swap_log.00
5394 cache_swap_log.01
5395 cache_swap_log.02
5473c134 5396
41bd17a4 5397 The numbered extension (which is added automatically)
5398 corresponds to the order of the 'cache_dir' lines in this
5399 configuration file. If you change the order of the 'cache_dir'
5400 lines in this file, these index files will NOT correspond to
5401 the correct 'cache_dir' entry (unless you manually rename
5402 them). We recommend you do NOT use this option. It is
5403 better to keep these index files in each 'cache_dir' directory.
5473c134 5404DOC_END
5405
41bd17a4 5406NAME: logfile_rotate
5407TYPE: int
5408DEFAULT: 10
5409LOC: Config.Log.rotateNumber
5473c134 5410DOC_START
efc23871 5411 Specifies the default number of logfile rotations to make when you
41bd17a4 5412 type 'squid -k rotate'. The default is 10, which will rotate
5413 with extensions 0 through 9. Setting logfile_rotate to 0 will
5414 disable the file name rotation, but the logfiles are still closed
5415 and re-opened. This will enable you to rename the logfiles
5416 yourself just before sending the rotate signal.
5473c134 5417
efc23871
AJ
5418 Note, from Squid-3.1 this option is only a default for cache.log,
5419 that log can be rotated separately by using debug_options.
5420
66f92ffc 5421 Note, from Squid-4 this option is only a default for access.log
efc23871
AJ
5422 recorded by stdio: module. Those logs can be rotated separately by
5423 using the rotate=N option on their access_log directive.
5424
41bd17a4 5425 Note, the 'squid -k rotate' command normally sends a USR1
5426 signal to the running squid process. In certain situations
5427 (e.g. on Linux with Async I/O), USR1 is used for other
5428 purposes, so -k rotate uses another signal. It is best to get
5429 in the habit of using 'squid -k rotate' instead of 'kill -USR1
5430 <pid>'.
62493678 5431
41bd17a4 5432DOC_END
5473c134 5433
41bd17a4 5434NAME: mime_table
5435TYPE: string
5436DEFAULT: @DEFAULT_MIME_TABLE@
5437LOC: Config.mimeTablePathname
5438DOC_START
638402dd
AJ
5439 Path to Squid's icon configuration file.
5440
5441 You shouldn't need to change this, but the default file contains
5442 examples and formatting information if you do.
5473c134 5443DOC_END
5444
41bd17a4 5445NAME: log_mime_hdrs
5446COMMENT: on|off
5447TYPE: onoff
5448LOC: Config.onoff.log_mime_hdrs
5449DEFAULT: off
5450DOC_START
5451 The Cache can record both the request and the response MIME
5452 headers for each HTTP transaction. The headers are encoded
5453 safely and will appear as two bracketed fields at the end of
5454 the access log (for either the native or httpd-emulated log
5455 formats). To enable this logging set log_mime_hdrs to 'on'.
5456DOC_END
5473c134 5457
41bd17a4 5458NAME: pid_filename
5459TYPE: string
5460DEFAULT: @DEFAULT_PID_FILE@
5461LOC: Config.pidFilename
5473c134 5462DOC_START
41bd17a4 5463 A filename to write the process-id to. To disable, enter "none".
5473c134 5464DOC_END
5465
41bd17a4 5466NAME: client_netmask
5467TYPE: address
5468LOC: Config.Addrs.client_netmask
0eb08770 5469DEFAULT: no_addr
638402dd 5470DEFAULT_DOC: Log full client IP address
5473c134 5471DOC_START
41bd17a4 5472 A netmask for client addresses in logfiles and cachemgr output.
5473 Change this to protect the privacy of your cache clients.
5474 A netmask of 255.255.255.0 will log all IP's in that range with
5475 the last digit set to '0'.
5473c134 5476DOC_END
5477
41bd17a4 5478NAME: strip_query_terms
5473c134 5479TYPE: onoff
41bd17a4 5480LOC: Config.onoff.strip_query_terms
5473c134 5481DEFAULT: on
5482DOC_START
41bd17a4 5483 By default, Squid strips query terms from requested URLs before
638402dd
AJ
5484 logging. This protects your user's privacy and reduces log size.
5485
5486 When investigating HIT/MISS or other caching behaviour you
5487 will need to disable this to see the full URL used by Squid.
5473c134 5488DOC_END
5489
41bd17a4 5490NAME: buffered_logs
5491COMMENT: on|off
5492TYPE: onoff
5493DEFAULT: off
5494LOC: Config.onoff.buffered_logs
5473c134 5495DOC_START
638402dd
AJ
5496 Whether to write/send access_log records ASAP or accumulate them and
5497 then write/send them in larger chunks. Buffering may improve
5498 performance because it decreases the number of I/Os. However,
5499 buffering increases the delay before log records become available to
5500 the final recipient (e.g., a disk file or logging daemon) and,
5501 hence, increases the risk of log records loss.
5502
5503 Note that even when buffered_logs are off, Squid may have to buffer
5504 records if it cannot write/send them immediately due to pending I/Os
5505 (e.g., the I/O writing the previous log record) or connectivity loss.
5506
fb0c2f17 5507 Currently honored by 'daemon' and 'tcp' access_log modules only.
6b698a21 5508DOC_END
0976f8db 5509
2b753521 5510NAME: netdb_filename
5511TYPE: string
221faecb 5512DEFAULT: stdio:@DEFAULT_NETDB_FILE@
2b753521 5513LOC: Config.netdbFilename
fb6a61d1 5514IFDEF: USE_ICMP
2b753521 5515DOC_START
638402dd
AJ
5516 Where Squid stores it's netdb journal.
5517 When enabled this journal preserves netdb state between restarts.
5518
2b753521 5519 To disable, enter "none".
5520DOC_END
5521
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AR
5522NAME: tls_key_log
5523TYPE: Security::KeyLog*
5524DEFAULT: none
5525LOC: Config.Log.tlsKeys
5526IFDEF: USE_OPENSSL
5527DOC_START
5528 Configures whether and where Squid records pre-master secret and
5529 related encryption details for TLS connections accepted or established
5530 by Squid. These connections include connections accepted at
5531 https_port, TLS connections opened to origin servers/cache_peers/ICAP
5532 services, and TLS tunnels bumped by Squid using the SslBump feature.
5533 This log (a.k.a. SSLKEYLOGFILE) is meant for triage with traffic
5534 inspection tools like Wireshark.
5535
5536 tls_key_log <destination> [options] [if [!]<acl>...]
5537
5538 WARNING: This log allows anybody to decrypt the corresponding
5539 encrypted TLS connections, both in-flight and postmortem.
5540
5541 At most one log file is supported at this time. Repeated tls_key_log
5542 directives are treated as fatal configuration errors. By default, no
5543 log is created or updated.
5544
5545 If the log file does not exist, Squid creates it. Otherwise, Squid
5546 appends an existing log file.
5547
5548 The directive is consulted whenever a TLS connection is accepted or
5549 established by Squid. TLS connections that fail the handshake may be
5550 logged if Squid got enough information to form a log record. A record
5551 is logged only if all of the configured ACLs match.
5552
5553 While transport-related ACLs like src and dst should work, Squid may
5554 not have access to higher-level information. For example, when logging
5555 accepted https_port connections, Squid does not yet have access to the
5556 expected HTTPS request. Similarly, an HTTPS response is not available
5557 when logging most TLS connections established by Squid.
5558
5559 The log record format is meant to be compatible with TLS deciphering
5560 features of Wireshark which relies on fields like CLIENT_RANDOM and
5561 RSA Master-Key. A single log record usually spans multiple lines.
5562 Technical documentation for that format is maintained inside the
5563 Wireshark code (e.g., see tls_keylog_process_lines() comments as of
5564 Wireshark commit e3d44136f0f0026c5e893fa249f458073f3b7328). TLS key
5565 log does not support custom record formats.
5566
5567 This clause only supports fast acl types.
5568 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5569
5570 See access_log's <module>:<place> parameter for a list of supported
5571 logging destinations.
5572
5573 TLS key log supports all access_log key=value options with the
5574 exception of logformat=name.
5575
5576 Requires Squid built with OpenSSL support.
5577DOC_END
5578
5579
62493678
AJ
5580COMMENT_START
5581 OPTIONS FOR TROUBLESHOOTING
5582 -----------------------------------------------------------------------------
5583COMMENT_END
5584
5585NAME: cache_log
5586TYPE: string
62493678
AJ
5587DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
5588LOC: Debug::cache_log
5589DOC_START
638402dd
AJ
5590 Squid administrative logging file.
5591
5592 This is where general information about Squid behavior goes. You can
5593 increase the amount of data logged to this file and how often it is
5594 rotated with "debug_options"
62493678
AJ
5595DOC_END
5596
c59baaa8
EB
5597NAME: cache_log_message
5598TYPE: cache_log_message
5599DEFAULT: none
5600DEFAULT_DOC: Use debug_options.
5601LOC: Config.debugMessages
5602DOC_START
5603 Configures logging of individual cache.log messages.
5604
5605 cache_log_message id=<number> option...
5606 cache_log_message ids=<number>-<number> option...
5607
5608 Most messages have _not_ been instrumented to support this directive
5609 yet. For the list of instrumented messages and their IDs, please see
5610 the doc/debug-messages.txt file.
5611
5612 Message ID corresponds to the message semantics rather than message
5613 text or source code location. The ID is stable across Squid
5614 instances and versions. Substantial changes in message semantics
5615 result in a new ID assignment. To reduce the danger of suppressing
5616 an important log message, the old IDs of removed (or substantially
5617 changed) messages are never reused.
5618
5619 If more than one cache_log_message directive refers to the same
5620 message ID, the last directive wins.
5621
5622 Use ids=min-max syntax to apply the same message configuration to an
5623 inclusive range of message IDs. An ID range with N values has
5624 exactly the same effect as typing N cache_log_message lines.
5625
5626 At least one option is required. Supported options are:
5627
5628 level=<number>: The logging level to use for the message. Squid
5629 command line options (-s and -d) as well as the debug_options
5630 directive control which levels go to syslog, stderr, and/or
5631 cache.log. In most environments, using level=2 or higher stops
5632 Squid from logging the message anywhere. By default, the
5633 hard-coded message-specific level is used.
5634
5635 limit=<number>: After logging the specified number of messages at
5636 the configured (or default) debugging level DL, start using
5637 level 3 (for DL 0 and 1) or 8 (for higher DL values). Usually,
5638 level-3+ messages are not logged anywhere so this option can
5639 often be used to effectively suppress the message. Each SMP
5640 Squid process gets the same limit.
5641DOC_END
5642
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AJ
5643NAME: debug_options
5644TYPE: eol
47df1aa7 5645DEFAULT: ALL,1
638402dd 5646DEFAULT_DOC: Log all critical and important messages.
62493678
AJ
5647LOC: Debug::debugOptions
5648DOC_START
5649 Logging options are set as section,level where each source file
5650 is assigned a unique section. Lower levels result in less
5651 output, Full debugging (level 9) can result in a very large
5652 log file, so be careful.
5653
5654 The magic word "ALL" sets debugging levels for all sections.
638402dd 5655 The default is to run with "ALL,1" to record important warnings.
62493678 5656
47df1aa7
AJ
5657 The rotate=N option can be used to keep more or less of these logs
5658 than would otherwise be kept by logfile_rotate.
62493678
AJ
5659 For most uses a single log should be enough to monitor current
5660 events affecting Squid.
5661DOC_END
5662
5663NAME: coredump_dir
5664TYPE: string
5665LOC: Config.coredump_dir
62493678 5666DEFAULT_IF_NONE: none
638402dd 5667DEFAULT_DOC: Use the directory from where Squid was started.
62493678
AJ
5668DOC_START
5669 By default Squid leaves core files in the directory from where
5670 it was started. If you set 'coredump_dir' to a directory
5671 that exists, Squid will chdir() to that directory at startup
5672 and coredump files will be left there.
5673
321223fe
DC
5674 In addition to changing the directory, the process permissions are updated
5675 to enable process tracing and/or coredump file generation. The details are
5676 OS-specific, but look for prctl(2) PR_SET_DUMPABLE and procctl(2)
5677 PROC_TRACE_CTL documentation as guiding examples.
5678
47f0eaea 5679CONFIG_START
e0855596 5680
62493678
AJ
5681# Leave coredumps in the first cache dir
5682coredump_dir @DEFAULT_SWAP_DIR@
47f0eaea 5683CONFIG_END
62493678
AJ
5684DOC_END
5685
5686
41bd17a4 5687COMMENT_START
5688 OPTIONS FOR FTP GATEWAYING
5689 -----------------------------------------------------------------------------
5690COMMENT_END
5691
5692NAME: ftp_user
5693TYPE: string
5694DEFAULT: Squid@
5695LOC: Config.Ftp.anon_user
6b698a21 5696DOC_START
41bd17a4 5697 If you want the anonymous login password to be more informative
638402dd 5698 (and enable the use of picky FTP servers), set this to something
41bd17a4 5699 reasonable for your domain, like wwwuser@somewhere.net
7f7db318 5700
41bd17a4 5701 The reason why this is domainless by default is the
5702 request can be made on the behalf of a user in any domain,
5703 depending on how the cache is used.
638402dd 5704 Some FTP server also validate the email address is valid
41bd17a4 5705 (for example perl.com).
6b698a21 5706DOC_END
0976f8db 5707
41bd17a4 5708NAME: ftp_passive
5709TYPE: onoff
5710DEFAULT: on
5711LOC: Config.Ftp.passive
6b698a21 5712DOC_START
41bd17a4 5713 If your firewall does not allow Squid to use passive
5714 connections, turn off this option.
a689bd4e 5715
5716 Use of ftp_epsv_all option requires this to be ON.
5717DOC_END
5718
5719NAME: ftp_epsv_all
5720TYPE: onoff
5721DEFAULT: off
5722LOC: Config.Ftp.epsv_all
5723DOC_START
5724 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
5725
5726 NATs may be able to put the connection on a "fast path" through the
5727 translator, as the EPRT command will never be used and therefore,
5728 translation of the data portion of the segments will never be needed.
5729
b3567eb5
FC
5730 When a client only expects to do two-way FTP transfers this may be
5731 useful.
a689bd4e 5732 If squid finds that it must do a three-way FTP transfer after issuing
5733 an EPSV ALL command, the FTP session will fail.
5734
5735 If you have any doubts about this option do not use it.
5736 Squid will nicely attempt all other connection methods.
5737
51ee534d
AJ
5738 Requires ftp_passive to be ON (default) for any effect.
5739DOC_END
5740
5741NAME: ftp_epsv
ddf5aa2b
CT
5742TYPE: ftp_epsv
5743DEFAULT: none
5744LOC: Config.accessList.ftp_epsv
51ee534d
AJ
5745DOC_START
5746 FTP Protocol extensions permit the use of a special "EPSV" command.
5747
5748 NATs may be able to put the connection on a "fast path" through the
b3567eb5 5749 translator using EPSV, as the EPRT command will never be used
9603207d 5750 and therefore, translation of the data portion of the segments
b3567eb5 5751 will never be needed.
51ee534d 5752
ddf5aa2b
CT
5753 EPSV is often required to interoperate with FTP servers on IPv6
5754 networks. On the other hand, it may break some IPv4 servers.
5755
5756 By default, EPSV may try EPSV with any FTP server. To fine tune
5757 that decision, you may restrict EPSV to certain clients or servers
5758 using ACLs:
5759
5760 ftp_epsv allow|deny al1 acl2 ...
5761
5762 WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
51ee534d 5763
ddf5aa2b 5764 Only fast ACLs are supported.
51ee534d 5765 Requires ftp_passive to be ON (default) for any effect.
41bd17a4 5766DOC_END
9e7dbc51 5767
63ee5443
AJ
5768NAME: ftp_eprt
5769TYPE: onoff
5770DEFAULT: on
5771LOC: Config.Ftp.eprt
5772DOC_START
5773 FTP Protocol extensions permit the use of a special "EPRT" command.
5774
5775 This extension provides a protocol neutral alternative to the
5776 IPv4-only PORT command. When supported it enables active FTP data
5777 channels over IPv6 and efficient NAT handling.
5778
5779 Turning this OFF will prevent EPRT being attempted and will skip
5780 straight to using PORT for IPv4 servers.
5781
5782 Some devices are known to not handle this extension correctly and
2f8abb64 5783 may result in crashes. Devices which support EPRT enough to fail
63ee5443
AJ
5784 cleanly will result in Squid attempting PORT anyway. This directive
5785 should only be disabled when EPRT results in device failures.
5786
5787 WARNING: Doing so will convert Squid back to the old behavior with all
5788 the related problems with external NAT devices/layers and IPv4-only FTP.
5789DOC_END
5790
41bd17a4 5791NAME: ftp_sanitycheck
5792TYPE: onoff
5793DEFAULT: on
5794LOC: Config.Ftp.sanitycheck
5795DOC_START
5796 For security and data integrity reasons Squid by default performs
5797 sanity checks of the addresses of FTP data connections ensure the
5798 data connection is to the requested server. If you need to allow
5799 FTP connections to servers using another IP address for the data
5800 connection turn this off.
5801DOC_END
9e7dbc51 5802
41bd17a4 5803NAME: ftp_telnet_protocol
5804TYPE: onoff
5805DEFAULT: on
5806LOC: Config.Ftp.telnet
5807DOC_START
5808 The FTP protocol is officially defined to use the telnet protocol
5809 as transport channel for the control connection. However, many
5810 implementations are broken and does not respect this aspect of
5811 the FTP protocol.
5812
5813 If you have trouble accessing files with ASCII code 255 in the
5814 path or similar problems involving this ASCII code you can
5815 try setting this directive to off. If that helps, report to the
5816 operator of the FTP server in question that their FTP server
5817 is broken and does not follow the FTP standard.
5818DOC_END
5819
5820COMMENT_START
5821 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
5822 -----------------------------------------------------------------------------
5823COMMENT_END
5824
5825NAME: diskd_program
5826TYPE: string
5827DEFAULT: @DEFAULT_DISKD@
5828LOC: Config.Program.diskd
5829DOC_START
5830 Specify the location of the diskd executable.
5831 Note this is only useful if you have compiled in
5832 diskd as one of the store io modules.
5833DOC_END
5834
5835NAME: unlinkd_program
5836IFDEF: USE_UNLINKD
5837TYPE: string
5838DEFAULT: @DEFAULT_UNLINKD@
5839LOC: Config.Program.unlinkd
5840DOC_START
5841 Specify the location of the executable for file deletion process.
5842DOC_END
5843
5844NAME: pinger_program
41bd17a4 5845IFDEF: USE_ICMP
7a9d36e3
AJ
5846TYPE: icmp
5847DEFAULT: @DEFAULT_PINGER@
5848LOC: IcmpCfg
41bd17a4 5849DOC_START
5850 Specify the location of the executable for the pinger process.
5851DOC_END
5852
cc192b50 5853NAME: pinger_enable
5854TYPE: onoff
5855DEFAULT: on
7a9d36e3 5856LOC: IcmpCfg.enable
cc192b50 5857IFDEF: USE_ICMP
5858DOC_START
5859 Control whether the pinger is active at run-time.
b3567eb5
FC
5860 Enables turning ICMP pinger on and off with a simple
5861 squid -k reconfigure.
cc192b50 5862DOC_END
5863
5864
41bd17a4 5865COMMENT_START
5866 OPTIONS FOR URL REWRITING
5867 -----------------------------------------------------------------------------
5868COMMENT_END
5869
5870NAME: url_rewrite_program redirect_program
5871TYPE: wordlist
5872LOC: Config.Program.redirect
5873DEFAULT: none
5874DOC_START
32f90fcf
PSB
5875 The name and command line parameters of an admin-provided executable
5876 for redirecting clients or adjusting/replacing client request URLs.
41bd17a4 5877
32f90fcf
PSB
5878 This helper is consulted after the received request is cleared by
5879 http_access and adapted using eICAP/ICAP services (if any). If the
5880 helper does not redirect the client, Squid checks adapted_http_access
5881 and may consult the cache or forward the request to the next hop.
41bd17a4 5882
5269ec0e 5883
32f90fcf 5884 For each request, the helper gets one line in the following format:
5269ec0e 5885
32f90fcf 5886 [channel-ID <SP>] request-URL [<SP> extras] <NL>
5269ec0e 5887
32f90fcf 5888 Use url_rewrite_extras to configure what Squid sends as 'extras'.
5269ec0e 5889
32f90fcf
PSB
5890
5891 The helper must reply to each query using a single line:
5892
5893 [channel-ID <SP>] result [<SP> kv-pairs] <NL>
5894
5895 The result section must match exactly one of the following outcomes:
5896
5897 OK [status=30N] url="..."
5898
5899 Redirect the client to a URL supplied in the 'url' parameter.
5900 Optional 'status' specifies the status code to send to the
5901 client in Squid's HTTP redirect response. It must be one of
5902 the standard HTTP redirect status codes: 301, 302, 303, 307,
5903 or 308. When no specific status is requested, Squid uses 302.
c71adec1 5904
5269ec0e 5905 OK rewrite-url="..."
32f90fcf
PSB
5906
5907 Replace the current request URL with the one supplied in the
5908 'rewrite-url' parameter. Squid fetches the resource specified
5909 by the new URL and forwards the received response (or its
5910 cached copy) to the client.
5911
5912 WARNING: Avoid rewriting URLs! When possible, redirect the
5913 client using an "OK url=..." helper response instead.
5914 Rewriting URLs may create inconsistent requests and/or break
5915 synchronization between internal client and origin server
5916 states, especially when URLs or other message parts contain
5917 snippets of that state. For example, Squid does not adjust
5918 Location headers and embedded URLs after the helper rewrites
5919 the request URL.
5269ec0e 5920
c2cbbb02 5921 OK
32f90fcf 5922 Keep the client request intact.
c2cbbb02 5923
5269ec0e 5924 ERR
32f90fcf 5925 Keep the client request intact.
5269ec0e 5926
32f90fcf
PSB
5927 BH [message="..."]
5928 A helper problem that should be reported to the Squid admin
5929 via a level-1 cache.log message. The 'message' parameter is
5930 reserved for specifying the log message.
5269ec0e 5931
32f90fcf
PSB
5932 In addition to the kv-pairs mentioned above, Squid also understands
5933 the following optional kv-pairs in URL rewriter responses:
5269ec0e 5934
457857fe
CT
5935 clt_conn_tag=TAG
5936 Associates a TAG with the client TCP connection.
41bd17a4 5937
32f90fcf
PSB
5938 The clt_conn_tag=TAG pair is treated as a regular transaction
5939 annotation for the current request and also annotates future
5940 requests on the same client connection. A helper may update
5941 the TAG during subsequent requests by returning a new kv-pair.
5269ec0e 5942
41bd17a4 5943
32f90fcf
PSB
5944 Helper messages contain the channel-ID part if and only if the
5945 url_rewrite_children directive specifies positive concurrency. As a
5946 channel-ID value, Squid sends a number between 0 and concurrency-1.
5947 The helper must echo back the received channel-ID in its response.
41bd17a4 5948
32f90fcf 5949 By default, Squid does not use a URL rewriter.
41bd17a4 5950DOC_END
5951
5952NAME: url_rewrite_children redirect_children
48d54e4d 5953TYPE: HelperChildConfig
5b708d95 5954DEFAULT: 20 startup=0 idle=1 concurrency=0
41bd17a4 5955LOC: Config.redirectChildren
5956DOC_START
79933cd6
AR
5957 Specifies the maximum number of redirector processes that Squid may
5958 spawn (numberofchildren) and several related options. Using too few of
5959 these helper processes (a.k.a. "helpers") creates request queues.
5960 Using too many helpers wastes your system resources.
5961
5962 Usage: numberofchildren [option]...
5963
48d54e4d
AJ
5964 The startup= and idle= options allow some measure of skew in your
5965 tuning.
9603207d 5966
48d54e4d 5967 startup=
9603207d 5968
48d54e4d
AJ
5969 Sets a minimum of how many processes are to be spawned when Squid
5970 starts or reconfigures. When set to zero the first request will
5971 cause spawning of the first child process to handle it.
9603207d 5972
48d54e4d
AJ
5973 Starting too few will cause an initial slowdown in traffic as Squid
5974 attempts to simultaneously spawn enough processes to cope.
9603207d 5975
48d54e4d 5976 idle=
9603207d 5977
48d54e4d
AJ
5978 Sets a minimum of how many processes Squid is to try and keep available
5979 at all times. When traffic begins to rise above what the existing
5980 processes can handle this many more will be spawned up to the maximum
5981 configured. A minimum setting of 1 is required.
5982
5983 concurrency=
41bd17a4 5984
41bd17a4 5985 The number of requests each redirector helper can handle in
5986 parallel. Defaults to 0 which indicates the redirector
5987 is a old-style single threaded redirector.
6a171502
AJ
5988
5989 When this directive is set to a value >= 1 then the protocol
5990 used to communicate with the helper is modified to include
9bef05b1
AJ
5991 an ID in front of the request/response. The ID from the request
5992 must be echoed back with the response to that request.
6825b101
CT
5993
5994 queue-size=N
5995
79933cd6
AR
5996 Sets the maximum number of queued requests. A request is queued when
5997 no existing child can accept it due to concurrency limit and no new
5998 child can be started due to numberofchildren limit. The default
5999 maximum is zero if url_rewrite_bypass is enabled and
6000 2*numberofchildren otherwise. If the queued requests exceed queue size
6001 and redirector_bypass configuration option is set, then redirector is
6002 bypassed. Otherwise, Squid is allowed to temporarily exceed the
6003 configured maximum, marking the affected helper as "overloaded". If
6004 the helper overload lasts more than 3 minutes, the action prescribed
6005 by the on-persistent-overload option applies.
6082a0e2
EB
6006
6007 on-persistent-overload=action
6008
6009 Specifies Squid reaction to a new helper request arriving when the helper
6010 has been overloaded for more that 3 minutes already. The number of queued
6011 requests determines whether the helper is overloaded (see the queue-size
6012 option).
6013
6014 Two actions are supported:
6015
6016 die Squid worker quits. This is the default behavior.
6017
6018 ERR Squid treats the helper request as if it was
6019 immediately submitted, and the helper immediately
6020 replied with an ERR response. This action has no effect
6021 on the already queued and in-progress helper requests.
41bd17a4 6022DOC_END
6023
6024NAME: url_rewrite_host_header redirect_rewrites_host_header
6025TYPE: onoff
6026DEFAULT: on
6027LOC: Config.onoff.redir_rewrites_host
6028DOC_START
3ce33807
AJ
6029 To preserve same-origin security policies in browsers and
6030 prevent Host: header forgery by redirectors Squid rewrites
6031 any Host: header in redirected requests.
9603207d 6032
3ce33807
AJ
6033 If you are running an accelerator this may not be a wanted
6034 effect of a redirector. This directive enables you disable
6035 Host: alteration in reverse-proxy traffic.
9603207d 6036
41bd17a4 6037 WARNING: Entries are cached on the result of the URL rewriting
6038 process, so be careful if you have domain-virtual hosts.
9603207d 6039
3ce33807
AJ
6040 WARNING: Squid and other software verifies the URL and Host
6041 are matching, so be careful not to relay through other proxies
6042 or inspecting firewalls with this disabled.
41bd17a4 6043DOC_END
6044
6045NAME: url_rewrite_access redirector_access
6046TYPE: acl_access
6047DEFAULT: none
638402dd 6048DEFAULT_DOC: Allow, unless rules exist in squid.conf.
41bd17a4 6049LOC: Config.accessList.redirector
6050DOC_START
6051 If defined, this access list specifies which requests are
638402dd 6052 sent to the redirector processes.
b3567eb5
FC
6053
6054 This clause supports both fast and slow acl types.
6055 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 6056DOC_END
6057
6058NAME: url_rewrite_bypass redirector_bypass
6059TYPE: onoff
6060LOC: Config.onoff.redirector_bypass
6061DEFAULT: off
6062DOC_START
6063 When this is 'on', a request will not go through the
6082a0e2
EB
6064 redirector if all the helpers are busy. If this is 'off' and the
6065 redirector queue grows too large, the action is prescribed by the
6066 on-persistent-overload option. You should only enable this if the
6067 redirectors are not critical to your caching system. If you use
41bd17a4 6068 redirectors for access control, and you enable this option,
6069 users may have access to pages they should not
6070 be allowed to request.
79933cd6
AR
6071
6072 Enabling this option sets the default url_rewrite_children queue-size
6073 option value to 0.
41bd17a4 6074DOC_END
6075
fe7966ec 6076NAME: url_rewrite_extras
b11724bb
CT
6077TYPE: TokenOrQuotedString
6078LOC: Config.redirector_extras
6079DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
6080DOC_START
6081 Specifies a string to be append to request line format for the
6082 rewriter helper. "Quoted" format values may contain spaces and
6083 logformat %macros. In theory, any logformat %macro can be used.
6084 In practice, a %macro expands as a dash (-) if the helper request is
6085 sent before the required macro information is available to Squid.
6086DOC_END
6087
32fd6d8a 6088NAME: url_rewrite_timeout
ced8def3
AJ
6089TYPE: UrlHelperTimeout
6090LOC: Config.onUrlRewriteTimeout
32fd6d8a
CT
6091DEFAULT: none
6092DEFAULT_DOC: Squid waits for the helper response forever
6093DOC_START
6094 Squid times active requests to redirector. The timeout value and Squid
6095 reaction to a timed out request are configurable using the following
6096 format:
6097
ced8def3 6098 url_rewrite_timeout timeout time-units on_timeout=<action> [response=<quoted-response>]
32fd6d8a
CT
6099
6100 supported timeout actions:
ced8def3 6101 fail Squid return a ERR_GATEWAY_FAILURE error page
32fd6d8a 6102
ced8def3 6103 bypass Do not re-write the URL
32fd6d8a 6104
ced8def3 6105 retry Send the lookup to the helper again
32fd6d8a 6106
ced8def3
AJ
6107 use_configured_response
6108 Use the <quoted-response> as helper response
32fd6d8a
CT
6109DOC_END
6110
a8a0b1c2
EC
6111COMMENT_START
6112 OPTIONS FOR STORE ID
6113 -----------------------------------------------------------------------------
6114COMMENT_END
6115
6116NAME: store_id_program storeurl_rewrite_program
6117TYPE: wordlist
6118LOC: Config.Program.store_id
6119DEFAULT: none
6120DOC_START
6121 Specify the location of the executable StoreID helper to use.
6122 Since they can perform almost any function there isn't one included.
6123
6124 For each requested URL, the helper will receive one line with the format
6125
b11724bb 6126 [channel-ID <SP>] URL [<SP> extras]<NL>
a8a0b1c2
EC
6127
6128
6129 After processing the request the helper must reply using the following format:
6130
6131 [channel-ID <SP>] result [<SP> kv-pairs]
6132
6133 The result code can be:
6134
6135 OK store-id="..."
6136 Use the StoreID supplied in 'store-id='.
6137
6138 ERR
6139 The default is to use HTTP request URL as the store ID.
6140
6141 BH
61beade2 6142 An internal error occurred in the helper, preventing
a8a0b1c2
EC
6143 a result being identified.
6144
457857fe
CT
6145 In addition to the above kv-pairs Squid also understands the following
6146 optional kv-pairs received from URL rewriters:
6147 clt_conn_tag=TAG
6148 Associates a TAG with the client TCP connection.
6149 Please see url_rewrite_program related documentation for this
6150 kv-pair
a8a0b1c2 6151
b11724bb
CT
6152 Helper programs should be prepared to receive and possibly ignore
6153 additional whitespace-separated tokens on each input line.
a8a0b1c2
EC
6154
6155 When using the concurrency= option the protocol is changed by
6156 introducing a query channel tag in front of the request/response.
6157 The query channel tag is a number between 0 and concurrency-1.
6158 This value must be echoed back unchanged to Squid as the first part
6159 of the response relating to its request.
6160
6161 NOTE: when using StoreID refresh_pattern will apply to the StoreID
6162 returned from the helper and not the URL.
6163
6164 WARNING: Wrong StoreID value returned by a careless helper may result
6165 in the wrong cached response returned to the user.
6166
6167 By default, a StoreID helper is not used.
6168DOC_END
6169
fe7966ec 6170NAME: store_id_extras
b11724bb
CT
6171TYPE: TokenOrQuotedString
6172LOC: Config.storeId_extras
6173DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
6174DOC_START
6175 Specifies a string to be append to request line format for the
6176 StoreId helper. "Quoted" format values may contain spaces and
6177 logformat %macros. In theory, any logformat %macro can be used.
6178 In practice, a %macro expands as a dash (-) if the helper request is
6179 sent before the required macro information is available to Squid.
6180DOC_END
6181
a8a0b1c2
EC
6182NAME: store_id_children storeurl_rewrite_children
6183TYPE: HelperChildConfig
6184DEFAULT: 20 startup=0 idle=1 concurrency=0
6185LOC: Config.storeIdChildren
6186DOC_START
79933cd6
AR
6187 Specifies the maximum number of StoreID helper processes that Squid
6188 may spawn (numberofchildren) and several related options. Using
6189 too few of these helper processes (a.k.a. "helpers") creates request
6190 queues. Using too many helpers wastes your system resources.
6191
6192 Usage: numberofchildren [option]...
9603207d 6193
a8a0b1c2
EC
6194 The startup= and idle= options allow some measure of skew in your
6195 tuning.
9603207d 6196
a8a0b1c2 6197 startup=
9603207d 6198
a8a0b1c2
EC
6199 Sets a minimum of how many processes are to be spawned when Squid
6200 starts or reconfigures. When set to zero the first request will
6201 cause spawning of the first child process to handle it.
9603207d 6202
a8a0b1c2
EC
6203 Starting too few will cause an initial slowdown in traffic as Squid
6204 attempts to simultaneously spawn enough processes to cope.
9603207d 6205
a8a0b1c2 6206 idle=
9603207d 6207
a8a0b1c2
EC
6208 Sets a minimum of how many processes Squid is to try and keep available
6209 at all times. When traffic begins to rise above what the existing
6210 processes can handle this many more will be spawned up to the maximum
6211 configured. A minimum setting of 1 is required.
6212
6213 concurrency=
6214
6215 The number of requests each storeID helper can handle in
6216 parallel. Defaults to 0 which indicates the helper
6217 is a old-style single threaded program.
6218
6219 When this directive is set to a value >= 1 then the protocol
6220 used to communicate with the helper is modified to include
6221 an ID in front of the request/response. The ID from the request
6222 must be echoed back with the response to that request.
6825b101
CT
6223
6224 queue-size=N
6225
79933cd6
AR
6226 Sets the maximum number of queued requests to N. A request is queued
6227 when no existing child can accept it due to concurrency limit and no
6228 new child can be started due to numberofchildren limit. The default
6229 maximum is 2*numberofchildren. If the queued requests exceed queue
6230 size and redirector_bypass configuration option is set, then
6231 redirector is bypassed. Otherwise, Squid is allowed to temporarily
6232 exceed the configured maximum, marking the affected helper as
6233 "overloaded". If the helper overload lasts more than 3 minutes, the
6234 action prescribed by the on-persistent-overload option applies.
6082a0e2
EB
6235
6236 on-persistent-overload=action
6237
6238 Specifies Squid reaction to a new helper request arriving when the helper
6239 has been overloaded for more that 3 minutes already. The number of queued
6240 requests determines whether the helper is overloaded (see the queue-size
6241 option).
6242
6243 Two actions are supported:
6244
6245 die Squid worker quits. This is the default behavior.
6246
6247 ERR Squid treats the helper request as if it was
6248 immediately submitted, and the helper immediately
6249 replied with an ERR response. This action has no effect
6250 on the already queued and in-progress helper requests.
a8a0b1c2
EC
6251DOC_END
6252
6253NAME: store_id_access storeurl_rewrite_access
6254TYPE: acl_access
6255DEFAULT: none
638402dd 6256DEFAULT_DOC: Allow, unless rules exist in squid.conf.
a8a0b1c2
EC
6257LOC: Config.accessList.store_id
6258DOC_START
6259 If defined, this access list specifies which requests are
6260 sent to the StoreID processes. By default all requests
6261 are sent.
6262
6263 This clause supports both fast and slow acl types.
6264 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6265DOC_END
6266
6267NAME: store_id_bypass storeurl_rewrite_bypass
6268TYPE: onoff
6269LOC: Config.onoff.store_id_bypass
6270DEFAULT: on
6271DOC_START
6272 When this is 'on', a request will not go through the
6082a0e2
EB
6273 helper if all helpers are busy. If this is 'off' and the helper
6274 queue grows too large, the action is prescribed by the
6275 on-persistent-overload option. You should only enable this if the
6276 helpers are not critical to your caching system. If you use
9603207d 6277 helpers for critical caching components, and you enable this
a8a0b1c2 6278 option, users may not get objects from cache.
6825b101
CT
6279 This options sets default queue-size option of the store_id_children
6280 to 0.
a8a0b1c2
EC
6281DOC_END
6282
41bd17a4 6283COMMENT_START
6284 OPTIONS FOR TUNING THE CACHE
6285 -----------------------------------------------------------------------------
6286COMMENT_END
6287
f04b37d8 6288NAME: cache no_cache
6289TYPE: acl_access
6290DEFAULT: none
70706149 6291DEFAULT_DOC: By default, this directive is unused and has no effect.
f04b37d8 6292LOC: Config.accessList.noCache
41bd17a4 6293DOC_START
70706149
AR
6294 Requests denied by this directive will not be served from the cache
6295 and their responses will not be stored in the cache. This directive
6296 has no effect on other transactions and on already cached responses.
f04b37d8 6297
b3567eb5
FC
6298 This clause supports both fast and slow acl types.
6299 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
70706149
AR
6300
6301 This and the two other similar caching directives listed below are
6302 checked at different transaction processing stages, have different
6303 access to response information, affect different cache operations,
6304 and differ in slow ACLs support:
6305
6306 * cache: Checked before Squid makes a hit/miss determination.
6307 No access to reply information!
6308 Denies both serving a hit and storing a miss.
6309 Supports both fast and slow ACLs.
6310 * send_hit: Checked after a hit was detected.
6311 Has access to reply (hit) information.
6312 Denies serving a hit only.
6313 Supports fast ACLs only.
6314 * store_miss: Checked before storing a cachable miss.
6315 Has access to reply (miss) information.
6316 Denies storing a miss only.
6317 Supports fast ACLs only.
6318
6319 If you are not sure which of the three directives to use, apply the
6320 following decision logic:
6321
6322 * If your ACL(s) are of slow type _and_ need response info, redesign.
6323 Squid does not support that particular combination at this time.
6324 Otherwise:
6325 * If your directive ACL(s) are of slow type, use "cache"; and/or
6326 * if your directive ACL(s) need no response info, use "cache".
6327 Otherwise:
6328 * If you do not want the response cached, use store_miss; and/or
6329 * if you do not want a hit on a cached response, use send_hit.
6330DOC_END
6331
6332NAME: send_hit
6333TYPE: acl_access
6334DEFAULT: none
6335DEFAULT_DOC: By default, this directive is unused and has no effect.
6336LOC: Config.accessList.sendHit
6337DOC_START
6338 Responses denied by this directive will not be served from the cache
6339 (but may still be cached, see store_miss). This directive has no
6340 effect on the responses it allows and on the cached objects.
6341
6342 Please see the "cache" directive for a summary of differences among
6343 store_miss, send_hit, and cache directives.
6344
6345 Unlike the "cache" directive, send_hit only supports fast acl
6346 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6347
6348 For example:
6349
6350 # apply custom Store ID mapping to some URLs
6351 acl MapMe dstdomain .c.example.com
6352 store_id_program ...
6353 store_id_access allow MapMe
6354
6355 # but prevent caching of special responses
6356 # such as 302 redirects that cause StoreID loops
6357 acl Ordinary http_status 200-299
6358 store_miss deny MapMe !Ordinary
6359
6360 # and do not serve any previously stored special responses
6361 # from the cache (in case they were already cached before
6362 # the above store_miss rule was in effect).
6363 send_hit deny MapMe !Ordinary
6364DOC_END
6365
6366NAME: store_miss
6367TYPE: acl_access
6368DEFAULT: none
6369DEFAULT_DOC: By default, this directive is unused and has no effect.
6370LOC: Config.accessList.storeMiss
6371DOC_START
6372 Responses denied by this directive will not be cached (but may still
6373 be served from the cache, see send_hit). This directive has no
6374 effect on the responses it allows and on the already cached responses.
6375
6376 Please see the "cache" directive for a summary of differences among
6377 store_miss, send_hit, and cache directives. See the
6378 send_hit directive for a usage example.
6379
6380 Unlike the "cache" directive, store_miss only supports fast acl
6381 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
41bd17a4 6382DOC_END
6383
570d3f75
AJ
6384NAME: max_stale
6385COMMENT: time-units
6386TYPE: time_t
6387LOC: Config.maxStale
6388DEFAULT: 1 week
6389DOC_START
6390 This option puts an upper limit on how stale content Squid
6391 will serve from the cache if cache validation fails.
2f8abb64 6392 Can be overridden by the refresh_pattern max-stale option.
570d3f75
AJ
6393DOC_END
6394
41bd17a4 6395NAME: refresh_pattern
6396TYPE: refreshpattern
6397LOC: Config.Refresh
6398DEFAULT: none
6399DOC_START
6400 usage: refresh_pattern [-i] regex min percent max [options]
9e7dbc51 6401
6b698a21 6402 By default, regular expressions are CASE-SENSITIVE. To make
6403 them case-insensitive, use the -i option.
9e7dbc51 6404
41bd17a4 6405 'Min' is the time (in minutes) an object without an explicit
6406 expiry time should be considered fresh. The recommended
6407 value is 0, any higher values may cause dynamic applications
6408 to be erroneously cached unless the application designer
6409 has taken the appropriate actions.
9e7dbc51 6410
41bd17a4 6411 'Percent' is a percentage of the objects age (time since last
6412 modification age) an object without explicit expiry time
6413 will be considered fresh.
5b807763 6414
41bd17a4 6415 'Max' is an upper limit on how long objects without an explicit
6d612a9d
GD
6416 expiry time will be considered fresh. The value is also used
6417 to form Cache-Control: max-age header for a request sent from
6418 Squid to origin/parent.
9e7dbc51 6419
41bd17a4 6420 options: override-expire
6421 override-lastmod
6422 reload-into-ims
6423 ignore-reload
41bd17a4 6424 ignore-no-store
6425 ignore-private
570d3f75 6426 max-stale=NN
41bd17a4 6427 refresh-ims
3d8b6ba4 6428 store-stale
a0ec9f68 6429
41bd17a4 6430 override-expire enforces min age even if the server
9b2ad080
HN
6431 sent an explicit expiry time (e.g., with the
6432 Expires: header or Cache-Control: max-age). Doing this
6433 VIOLATES the HTTP standard. Enabling this feature
6434 could make you liable for problems which it causes.
6468fe10 6435
04925576
AJ
6436 Note: override-expire does not enforce staleness - it only extends
6437 freshness / min. If the server returns a Expires time which
6438 is longer than your max time, Squid will still consider
6439 the object fresh for that period of time.
6440
41bd17a4 6441 override-lastmod enforces min age even on objects
6442 that were modified recently.
934b03fc 6443
46017fdd
CT
6444 reload-into-ims changes a client no-cache or ``reload''
6445 request for a cached entry into a conditional request using
6446 If-Modified-Since and/or If-None-Match headers, provided the
6447 cached entry has a Last-Modified and/or a strong ETag header.
6448 Doing this VIOLATES the HTTP standard. Enabling this feature
6449 could make you liable for problems which it causes.
dba79ac5 6450
41bd17a4 6451 ignore-reload ignores a client no-cache or ``reload''
6452 header. Doing this VIOLATES the HTTP standard. Enabling
6453 this feature could make you liable for problems which
6454 it causes.
9bc73deb 6455
41bd17a4 6456 ignore-no-store ignores any ``Cache-control: no-store''
6457 headers received from a server. Doing this VIOLATES
6458 the HTTP standard. Enabling this feature could make you
6459 liable for problems which it causes.
6460
6461 ignore-private ignores any ``Cache-control: private''
6462 headers received from a server. Doing this VIOLATES
6463 the HTTP standard. Enabling this feature could make you
6464 liable for problems which it causes.
6465
41bd17a4 6466 refresh-ims causes squid to contact the origin server
6467 when a client issues an If-Modified-Since request. This
6468 ensures that the client will receive an updated version
6469 if one is available.
6470
9603207d 6471 store-stale stores responses even if they don't have explicit
6472 freshness or a validator (i.e., Last-Modified or an ETag)
6473 present, or if they're already stale. By default, Squid will
3d8b6ba4
AJ
6474 not cache such responses because they usually can't be
6475 reused. Note that such responses will be stale by default.
6476
570d3f75
AJ
6477 max-stale=NN provide a maximum staleness factor. Squid won't
6478 serve objects more stale than this even if it failed to
6479 validate the object. Default: use the max_stale global limit.
6480
41bd17a4 6481 Basically a cached object is:
6482
fb41bbb2 6483 FRESH if expire > now, else STALE
41bd17a4 6484 STALE if age > max
6485 FRESH if lm-factor < percent, else STALE
6486 FRESH if age < min
6487 else STALE
6488
6489 The refresh_pattern lines are checked in the order listed here.
6490 The first entry which matches is used. If none of the entries
6491 match the default will be used.
6492
6493 Note, you must uncomment all the default lines if you want
6494 to change one. The default setting is only active if none is
6495 used.
6496
47f0eaea 6497CONFIG_START
e0855596 6498
638402dd 6499#
e0855596 6500# Add any of your own refresh_pattern entries above these.
638402dd 6501#
41bd17a4 6502refresh_pattern ^ftp: 1440 20% 10080
89db45fa 6503refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
41bd17a4 6504refresh_pattern . 0 20% 4320
47f0eaea 6505CONFIG_END
41bd17a4 6506DOC_END
6507
6508NAME: quick_abort_min
6509COMMENT: (KB)
6510TYPE: kb_int64_t
6511DEFAULT: 16 KB
6512LOC: Config.quickAbort.min
6513DOC_NONE
6514
6515NAME: quick_abort_max
6516COMMENT: (KB)
6517TYPE: kb_int64_t
6518DEFAULT: 16 KB
6519LOC: Config.quickAbort.max
6520DOC_NONE
6521
6522NAME: quick_abort_pct
6523COMMENT: (percent)
6524TYPE: int
6525DEFAULT: 95
6526LOC: Config.quickAbort.pct
6527DOC_START
6528 The cache by default continues downloading aborted requests
6529 which are almost completed (less than 16 KB remaining). This
6530 may be undesirable on slow (e.g. SLIP) links and/or very busy
6531 caches. Impatient users may tie up file descriptors and
6532 bandwidth by repeatedly requesting and immediately aborting
6533 downloads.
6534
6535 When the user aborts a request, Squid will check the
2d4eefd9 6536 quick_abort values to the amount of data transferred until
41bd17a4 6537 then.
6538
6539 If the transfer has less than 'quick_abort_min' KB remaining,
6540 it will finish the retrieval.
6541
6542 If the transfer has more than 'quick_abort_max' KB remaining,
6543 it will abort the retrieval.
6544
6545 If more than 'quick_abort_pct' of the transfer has completed,
6546 it will finish the retrieval.
6547
6548 If you do not want any retrieval to continue after the client
6549 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
6550 to '0 KB'.
6551
6552 If you want retrievals to always continue if they are being
6553 cached set 'quick_abort_min' to '-1 KB'.
6554DOC_END
60d096f4 6555
41bd17a4 6556NAME: read_ahead_gap
6557COMMENT: buffer-size
6558TYPE: b_int64_t
6559LOC: Config.readAheadGap
6560DEFAULT: 16 KB
6561DOC_START
6562 The amount of data the cache will buffer ahead of what has been
6563 sent to the client when retrieving an object from another server.
6564DOC_END
53e738c6 6565
41bd17a4 6566NAME: negative_ttl
626096be 6567IFDEF: USE_HTTP_VIOLATIONS
41bd17a4 6568COMMENT: time-units
6569TYPE: time_t
6570LOC: Config.negativeTtl
ac9cc053 6571DEFAULT: 0 seconds
41bd17a4 6572DOC_START
ac9cc053
AJ
6573 Set the Default Time-to-Live (TTL) for failed requests.
6574 Certain types of failures (such as "connection refused" and
6575 "404 Not Found") are able to be negatively-cached for a short time.
6576 Modern web servers should provide Expires: header, however if they
6577 do not this can provide a minimum TTL.
6578 The default is not to cache errors with unknown expiry details.
6579
6580 Note that this is different from negative caching of DNS lookups.
39956c7c
AJ
6581
6582 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6583 this feature could make you liable for problems which it
6584 causes.
41bd17a4 6585DOC_END
53e738c6 6586
41bd17a4 6587NAME: positive_dns_ttl
6588COMMENT: time-units
6589TYPE: time_t
6590LOC: Config.positiveDnsTtl
6591DEFAULT: 6 hours
6592DOC_START
6593 Upper limit on how long Squid will cache positive DNS responses.
6594 Default is 6 hours (360 minutes). This directive must be set
6595 larger than negative_dns_ttl.
6596DOC_END
c4ab8329 6597
41bd17a4 6598NAME: negative_dns_ttl
6599COMMENT: time-units
6600TYPE: time_t
6601LOC: Config.negativeDnsTtl
6602DEFAULT: 1 minutes
6603DOC_START
6604 Time-to-Live (TTL) for negative caching of failed DNS lookups.
6605 This also sets the lower cache limit on positive lookups.
6606 Minimum value is 1 second, and it is not recommendable to go
6607 much below 10 seconds.
6608DOC_END
7df0bfd7 6609
41bd17a4 6610NAME: range_offset_limit
11e3fa1c
AJ
6611COMMENT: size [acl acl...]
6612TYPE: acl_b_size_t
41bd17a4 6613LOC: Config.rangeOffsetLimit
11e3fa1c 6614DEFAULT: none
41bd17a4 6615DOC_START
11e3fa1c 6616 usage: (size) [units] [[!]aclname]
9603207d 6617
6618 Sets an upper limit on how far (number of bytes) into the file
6619 a Range request may be to cause Squid to prefetch the whole file.
6620 If beyond this limit, Squid forwards the Range request as it is and
11e3fa1c 6621 the result is NOT cached.
9603207d 6622
41bd17a4 6623 This is to stop a far ahead range request (lets say start at 17MB)
6624 from making Squid fetch the whole object up to that point before
6625 sending anything to the client.
9603207d 6626
6627 Multiple range_offset_limit lines may be specified, and they will
6628 be searched from top to bottom on each request until a match is found.
6629 The first match found will be used. If no line matches a request, the
11e3fa1c 6630 default limit of 0 bytes will be used.
9603207d 6631
11e3fa1c 6632 'size' is the limit specified as a number of units.
9603207d 6633
11e3fa1c
AJ
6634 'units' specifies whether to use bytes, KB, MB, etc.
6635 If no units are specified bytes are assumed.
9603207d 6636
11e3fa1c 6637 A size of 0 causes Squid to never fetch more than the
ab275c7b 6638 client requested. (default)
9603207d 6639
11e3fa1c 6640 A size of 'none' causes Squid to always fetch the object from the
41bd17a4 6641 beginning so it may cache the result. (2.0 style)
9603207d 6642
11e3fa1c 6643 'aclname' is the name of a defined ACL.
9603207d 6644
6645 NP: Using 'none' as the byte value here will override any quick_abort settings
11e3fa1c 6646 that may otherwise apply to the range request. The range request will
ab275c7b
AJ
6647 be fully fetched from start to finish regardless of the client
6648 actions. This affects bandwidth usage.
41bd17a4 6649DOC_END
d95b862f 6650
41bd17a4 6651NAME: minimum_expiry_time
6652COMMENT: (seconds)
6653TYPE: time_t
6654LOC: Config.minimum_expiry_time
6655DEFAULT: 60 seconds
6656DOC_START
6657 The minimum caching time according to (Expires - Date)
638402dd
AJ
6658 headers Squid honors if the object can't be revalidated.
6659 The default is 60 seconds.
6660
6661 In reverse proxy environments it might be desirable to honor
6662 shorter object lifetimes. It is most likely better to make
6663 your server return a meaningful Last-Modified header however.
6664
6665 In ESI environments where page fragments often have short
6666 lifetimes, this will often be best set to 0.
41bd17a4 6667DOC_END
c68e9c6b 6668
41bd17a4 6669NAME: store_avg_object_size
58d5c5dd
DK
6670COMMENT: (bytes)
6671TYPE: b_int64_t
41bd17a4 6672DEFAULT: 13 KB
6673LOC: Config.Store.avgObjectSize
6674DOC_START
6675 Average object size, used to estimate number of objects your
6676 cache can hold. The default is 13 KB.
638402dd
AJ
6677
6678 This is used to pre-seed the cache index memory allocation to
6679 reduce expensive reallocate operations while handling clients
6680 traffic. Too-large values may result in memory allocation during
6681 peak traffic, too-small values will result in wasted memory.
6682
6683 Check the cache manager 'info' report metrics for the real
6684 object sizes seen by your Squid before tuning this.
cccac0a2 6685DOC_END
6686
41bd17a4 6687NAME: store_objects_per_bucket
6688TYPE: int
6689DEFAULT: 20
6690LOC: Config.Store.objectsPerBucket
6691DOC_START
6692 Target number of objects per bucket in the store hash table.
6693 Lowering this value increases the total number of buckets and
6694 also the storage maintenance rate. The default is 20.
6695DOC_END
6696
6697COMMENT_START
6698 HTTP OPTIONS
6699 -----------------------------------------------------------------------------
6700COMMENT_END
6701
f04b37d8 6702NAME: request_header_max_size
6703COMMENT: (KB)
6704TYPE: b_size_t
df2eec10 6705DEFAULT: 64 KB
f04b37d8 6706LOC: Config.maxRequestHeaderSize
6707DOC_START
6708 This specifies the maximum size for HTTP headers in a request.
6709 Request headers are usually relatively small (about 512 bytes).
6710 Placing a limit on the request header size will catch certain
6711 bugs (for example with persistent connections) and possibly
6712 buffer-overflow or denial-of-service attacks.
6713DOC_END
6714
6715NAME: reply_header_max_size
6716COMMENT: (KB)
6717TYPE: b_size_t
df2eec10 6718DEFAULT: 64 KB
f04b37d8 6719LOC: Config.maxReplyHeaderSize
6720DOC_START
6721 This specifies the maximum size for HTTP headers in a reply.
6722 Reply headers are usually relatively small (about 512 bytes).
6723 Placing a limit on the reply header size will catch certain
6724 bugs (for example with persistent connections) and possibly
6725 buffer-overflow or denial-of-service attacks.
6726DOC_END
6727
6728NAME: request_body_max_size
6729COMMENT: (bytes)
6730TYPE: b_int64_t
6731DEFAULT: 0 KB
638402dd 6732DEFAULT_DOC: No limit.
f04b37d8 6733LOC: Config.maxRequestBodySize
6734DOC_START
6735 This specifies the maximum size for an HTTP request body.
6736 In other words, the maximum size of a PUT/POST request.
6737 A user who attempts to send a request with a body larger
6738 than this limit receives an "Invalid Request" error message.
6739 If you set this parameter to a zero (the default), there will
6740 be no limit imposed.
638402dd
AJ
6741
6742 See also client_request_buffer_max_size for an alternative
6743 limitation on client uploads which can be configured.
f04b37d8 6744DOC_END
6745
1368d115
CT
6746NAME: client_request_buffer_max_size
6747COMMENT: (bytes)
6748TYPE: b_size_t
6749DEFAULT: 512 KB
6750LOC: Config.maxRequestBufferSize
6751DOC_START
6752 This specifies the maximum buffer size of a client request.
6753 It prevents squid eating too much memory when somebody uploads
6754 a large file.
6755DOC_END
6756
41bd17a4 6757NAME: broken_posts
626096be 6758IFDEF: USE_HTTP_VIOLATIONS
cccac0a2 6759TYPE: acl_access
cccac0a2 6760DEFAULT: none
638402dd 6761DEFAULT_DOC: Obey RFC 2616.
41bd17a4 6762LOC: Config.accessList.brokenPosts
cccac0a2 6763DOC_START
41bd17a4 6764 A list of ACL elements which, if matched, causes Squid to send
6765 an extra CRLF pair after the body of a PUT/POST request.
cccac0a2 6766
41bd17a4 6767 Some HTTP servers has broken implementations of PUT/POST,
6768 and rely on an extra CRLF pair sent by some WWW clients.
cccac0a2 6769
41bd17a4 6770 Quote from RFC2616 section 4.1 on this matter:
cccac0a2 6771
41bd17a4 6772 Note: certain buggy HTTP/1.0 client implementations generate an
6773 extra CRLF's after a POST request. To restate what is explicitly
6774 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
6775 a request with an extra CRLF.
cccac0a2 6776
b3567eb5
FC
6777 This clause only supports fast acl types.
6778 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6779
41bd17a4 6780Example:
6781 acl buggy_server url_regex ^http://....
6782 broken_posts allow buggy_server
6783DOC_END
cccac0a2 6784
22fff3bf 6785NAME: adaptation_uses_indirect_client icap_uses_indirect_client
57d76dd4
AJ
6786COMMENT: on|off
6787TYPE: onoff
22fff3bf 6788IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
57d76dd4 6789DEFAULT: on
22fff3bf 6790LOC: Adaptation::Config::use_indirect_client
57d76dd4 6791DOC_START
ea3ae478
AR
6792 Controls whether the indirect client IP address (instead of the direct
6793 client IP address) is passed to adaptation services.
6794
6795 See also: follow_x_forwarded_for adaptation_send_client_ip
57d76dd4
AJ
6796DOC_END
6797
41bd17a4 6798NAME: via
626096be 6799IFDEF: USE_HTTP_VIOLATIONS
41bd17a4 6800COMMENT: on|off
6801TYPE: onoff
6802DEFAULT: on
6803LOC: Config.onoff.via
6804DOC_START
6805 If set (default), Squid will include a Via header in requests and
6806 replies as required by RFC2616.
6807DOC_END
4cc6eb12 6808
41bd17a4 6809NAME: vary_ignore_expire
6810COMMENT: on|off
6811TYPE: onoff
6812LOC: Config.onoff.vary_ignore_expire
6813DEFAULT: off
6814DOC_START
6815 Many HTTP servers supporting Vary gives such objects
6816 immediate expiry time with no cache-control header
6817 when requested by a HTTP/1.0 client. This option
6818 enables Squid to ignore such expiry times until
6819 HTTP/1.1 is fully implemented.
7e73cd78
AJ
6820
6821 WARNING: If turned on this may eventually cause some
6822 varying objects not intended for caching to get cached.
cccac0a2 6823DOC_END
c4ab8329 6824
41bd17a4 6825NAME: request_header_access
626096be 6826IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6827TYPE: http_header_access
41bd17a4 6828LOC: Config.request_header_access
cccac0a2 6829DEFAULT: none
638402dd 6830DEFAULT_DOC: No limits.
cccac0a2 6831DOC_START
41bd17a4 6832 Usage: request_header_access header_name allow|deny [!]aclname ...
0976f8db 6833
41bd17a4 6834 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6835 this feature could make you liable for problems which it
6836 causes.
0976f8db 6837
41bd17a4 6838 This option replaces the old 'anonymize_headers' and the
6839 older 'http_anonymizer' option with something that is much
3b07476b
CT
6840 more configurable. A list of ACLs for each header name allows
6841 removal of specific header fields under specific conditions.
6842
6843 This option only applies to outgoing HTTP request headers (i.e.,
6844 headers sent by Squid to the next HTTP hop such as a cache peer
6845 or an origin server). The option has no effect during cache hit
6846 detection. The equivalent adaptation vectoring point in ICAP
6847 terminology is post-cache REQMOD.
6848
6849 The option is applied to individual outgoing request header
6850 fields. For each request header field F, Squid uses the first
6851 qualifying sets of request_header_access rules:
6852
6853 1. Rules with header_name equal to F's name.
6854 2. Rules with header_name 'Other', provided F's name is not
6855 on the hard-coded list of commonly used HTTP header names.
6856 3. Rules with header_name 'All'.
6857
6858 Within that qualifying rule set, rule ACLs are checked as usual.
6859 If ACLs of an "allow" rule match, the header field is allowed to
6860 go through as is. If ACLs of a "deny" rule match, the header is
6861 removed and request_header_replace is then checked to identify
6862 if the removed header has a replacement. If no rules within the
6863 set have matching ACLs, the header field is left as is.
5401aa8d 6864
41bd17a4 6865 For example, to achieve the same behavior as the old
6866 'http_anonymizer standard' option, you should use:
5401aa8d 6867
41bd17a4 6868 request_header_access From deny all
6869 request_header_access Referer deny all
41bd17a4 6870 request_header_access User-Agent deny all
5401aa8d 6871
41bd17a4 6872 Or, to reproduce the old 'http_anonymizer paranoid' feature
6873 you should use:
5401aa8d 6874
41bd17a4 6875 request_header_access Authorization allow all
41bd17a4 6876 request_header_access Proxy-Authorization allow all
41bd17a4 6877 request_header_access Cache-Control allow all
41bd17a4 6878 request_header_access Content-Length allow all
6879 request_header_access Content-Type allow all
6880 request_header_access Date allow all
41bd17a4 6881 request_header_access Host allow all
6882 request_header_access If-Modified-Since allow all
41bd17a4 6883 request_header_access Pragma allow all
6884 request_header_access Accept allow all
6885 request_header_access Accept-Charset allow all
6886 request_header_access Accept-Encoding allow all
6887 request_header_access Accept-Language allow all
41bd17a4 6888 request_header_access Connection allow all
41bd17a4 6889 request_header_access All deny all
5401aa8d 6890
638402dd 6891 HTTP reply headers are controlled with the reply_header_access directive.
5401aa8d 6892
638402dd 6893 By default, all headers are allowed (no anonymizing is performed).
5401aa8d 6894DOC_END
6895
41bd17a4 6896NAME: reply_header_access
626096be 6897IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6898TYPE: http_header_access
41bd17a4 6899LOC: Config.reply_header_access
cccac0a2 6900DEFAULT: none
638402dd 6901DEFAULT_DOC: No limits.
cccac0a2 6902DOC_START
41bd17a4 6903 Usage: reply_header_access header_name allow|deny [!]aclname ...
934b03fc 6904
41bd17a4 6905 WARNING: Doing this VIOLATES the HTTP standard. Enabling
6906 this feature could make you liable for problems which it
6907 causes.
934b03fc 6908
41bd17a4 6909 This option only applies to reply headers, i.e., from the
6910 server to the client.
934b03fc 6911
41bd17a4 6912 This is the same as request_header_access, but in the other
3b07476b
CT
6913 direction. Please see request_header_access for detailed
6914 documentation.
cccac0a2 6915
41bd17a4 6916 For example, to achieve the same behavior as the old
6917 'http_anonymizer standard' option, you should use:
cccac0a2 6918
41bd17a4 6919 reply_header_access Server deny all
41bd17a4 6920 reply_header_access WWW-Authenticate deny all
6921 reply_header_access Link deny all
cccac0a2 6922
41bd17a4 6923 Or, to reproduce the old 'http_anonymizer paranoid' feature
6924 you should use:
cccac0a2 6925
41bd17a4 6926 reply_header_access Allow allow all
41bd17a4 6927 reply_header_access WWW-Authenticate allow all
41bd17a4 6928 reply_header_access Proxy-Authenticate allow all
6929 reply_header_access Cache-Control allow all
6930 reply_header_access Content-Encoding allow all
6931 reply_header_access Content-Length allow all
6932 reply_header_access Content-Type allow all
6933 reply_header_access Date allow all
6934 reply_header_access Expires allow all
41bd17a4 6935 reply_header_access Last-Modified allow all
6936 reply_header_access Location allow all
6937 reply_header_access Pragma allow all
41bd17a4 6938 reply_header_access Content-Language allow all
41bd17a4 6939 reply_header_access Retry-After allow all
6940 reply_header_access Title allow all
638402dd 6941 reply_header_access Content-Disposition allow all
41bd17a4 6942 reply_header_access Connection allow all
41bd17a4 6943 reply_header_access All deny all
cccac0a2 6944
638402dd 6945 HTTP request headers are controlled with the request_header_access directive.
cccac0a2 6946
41bd17a4 6947 By default, all headers are allowed (no anonymizing is
6948 performed).
cccac0a2 6949DOC_END
6950
75e4f2ea 6951NAME: request_header_replace header_replace
626096be 6952IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6953TYPE: http_header_replace
41bd17a4 6954LOC: Config.request_header_access
cccac0a2 6955DEFAULT: none
41bd17a4 6956DOC_START
75e4f2ea
MB
6957 Usage: request_header_replace header_name message
6958 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
cccac0a2 6959
41bd17a4 6960 This option allows you to change the contents of headers
75e4f2ea 6961 denied with request_header_access above, by replacing them
638402dd 6962 with some fixed string.
cccac0a2 6963
41bd17a4 6964 This only applies to request headers, not reply headers.
cccac0a2 6965
41bd17a4 6966 By default, headers are removed if denied.
6967DOC_END
cccac0a2 6968
75e4f2ea
MB
6969NAME: reply_header_replace
6970IFDEF: USE_HTTP_VIOLATIONS
3b07476b 6971TYPE: http_header_replace
75e4f2ea
MB
6972LOC: Config.reply_header_access
6973DEFAULT: none
6974DOC_START
6975 Usage: reply_header_replace header_name message
6976 Example: reply_header_replace Server Foo/1.0
6977
6978 This option allows you to change the contents of headers
6979 denied with reply_header_access above, by replacing them
6980 with some fixed string.
6981
6982 This only applies to reply headers, not request headers.
6983
6984 By default, headers are removed if denied.
6985DOC_END
6986
f4698e0b
CT
6987NAME: request_header_add
6988TYPE: HeaderWithAclList
6989LOC: Config.request_header_add
6990DEFAULT: none
6991DOC_START
cde8f31b 6992 Usage: request_header_add field-name field-value [ acl ... ]
f4698e0b
CT
6993 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
6994
6995 This option adds header fields to outgoing HTTP requests (i.e.,
6996 request headers sent by Squid to the next HTTP hop such as a
6997 cache peer or an origin server). The option has no effect during
6998 cache hit detection. The equivalent adaptation vectoring point
6999 in ICAP terminology is post-cache REQMOD.
7000
7001 Field-name is a token specifying an HTTP header name. If a
7002 standard HTTP header name is used, Squid does not check whether
7003 the new header conflicts with any existing headers or violates
7004 HTTP rules. If the request to be modified already contains a
7005 field with the same name, the old field is preserved but the
7006 header field values are not merged.
7007
7008 Field-value is either a token or a quoted string. If quoted
7009 string format is used, then the surrounding quotes are removed
7010 while escape sequences and %macros are processed.
7011
f4698e0b
CT
7012 One or more Squid ACLs may be specified to restrict header
7013 injection to matching requests. As always in squid.conf, all
cde8f31b
NH
7014 ACLs in the ACL list must be satisfied for the insertion to
7015 happen. The request_header_add supports fast ACLs only.
7016
7017 See also: reply_header_add.
7018DOC_END
7019
7020NAME: reply_header_add
7021TYPE: HeaderWithAclList
7022LOC: Config.reply_header_add
7023DEFAULT: none
7024DOC_START
7025 Usage: reply_header_add field-name field-value [ acl ... ]
7026 Example: reply_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
7027
7028 This option adds header fields to outgoing HTTP responses (i.e., response
7029 headers delivered by Squid to the client). This option has no effect on
7030 cache hit detection. The equivalent adaptation vectoring point in
7031 ICAP terminology is post-cache RESPMOD. This option does not apply to
7032 successful CONNECT replies.
7033
7034 Field-name is a token specifying an HTTP header name. If a
7035 standard HTTP header name is used, Squid does not check whether
7036 the new header conflicts with any existing headers or violates
7037 HTTP rules. If the response to be modified already contains a
7038 field with the same name, the old field is preserved but the
7039 header field values are not merged.
7040
7041 Field-value is either a token or a quoted string. If quoted
7042 string format is used, then the surrounding quotes are removed
7043 while escape sequences and %macros are processed.
7044
7045 One or more Squid ACLs may be specified to restrict header
7046 injection to matching responses. As always in squid.conf, all
7047 ACLs in the ACL list must be satisfied for the insertion to
7048 happen. The reply_header_add option supports fast ACLs only.
7049
7050 See also: request_header_add.
f4698e0b
CT
7051DOC_END
7052
d7f4a0b7
CT
7053NAME: note
7054TYPE: note
7055LOC: Config.notes
7056DEFAULT: none
7057DOC_START
7058 This option used to log custom information about the master
7059 transaction. For example, an admin may configure Squid to log
7060 which "user group" the transaction belongs to, where "user group"
7061 will be determined based on a set of ACLs and not [just]
7062 authentication information.
7063 Values of key/value pairs can be logged using %{key}note macros:
7064
7065 note key value acl ...
7066 logformat myFormat ... %{key}note ...
480926bd
EB
7067
7068 This clause only supports fast acl types.
7069 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
d7f4a0b7
CT
7070DOC_END
7071
41bd17a4 7072NAME: relaxed_header_parser
7073COMMENT: on|off|warn
7074TYPE: tristate
7075LOC: Config.onoff.relaxed_header_parser
7076DEFAULT: on
7077DOC_START
7078 In the default "on" setting Squid accepts certain forms
7079 of non-compliant HTTP messages where it is unambiguous
7080 what the sending application intended even if the message
7081 is not correctly formatted. The messages is then normalized
7082 to the correct form when forwarded by Squid.
cccac0a2 7083
41bd17a4 7084 If set to "warn" then a warning will be emitted in cache.log
7085 each time such HTTP error is encountered.
cccac0a2 7086
41bd17a4 7087 If set to "off" then such HTTP errors will cause the request
7088 or response to be rejected.
7089DOC_END
7d90757b 7090
55eae904
AR
7091NAME: collapsed_forwarding
7092COMMENT: (on|off)
7093TYPE: onoff
7094LOC: Config.onoff.collapsed_forwarding
7095DEFAULT: off
7096DOC_START
7097 This option controls whether Squid is allowed to merge multiple
7098 potentially cachable requests for the same URI before Squid knows
7099 whether the response is going to be cachable.
7100
1a210de4
EB
7101 When enabled, instead of forwarding each concurrent request for
7102 the same URL, Squid just sends the first of them. The other, so
7103 called "collapsed" requests, wait for the response to the first
7104 request and, if it happens to be cachable, use that response.
7105 Here, "concurrent requests" means "received after the first
7106 request headers were parsed and before the corresponding response
7107 headers were parsed".
7108
7109 This feature is disabled by default: enabling collapsed
7110 forwarding needlessly delays forwarding requests that look
7111 cachable (when they are collapsed) but then need to be forwarded
7112 individually anyway because they end up being for uncachable
7113 content. However, in some cases, such as acceleration of highly
7114 cachable content with periodic or grouped expiration times, the
7115 gains from collapsing [large volumes of simultaneous refresh
7116 requests] outweigh losses from such delays.
7117
7118 Squid collapses two kinds of requests: regular client requests
7119 received on one of the listening ports and internal "cache
7120 revalidation" requests which are triggered by those regular
7121 requests hitting a stale cached object. Revalidation collapsing
7122 is currently disabled for Squid instances containing SMP-aware
7123 disk or memory caches and for Vary-controlled cached objects.
55eae904
AR
7124DOC_END
7125
819be284
EB
7126NAME: collapsed_forwarding_access
7127TYPE: acl_access
7128DEFAULT: none
7129DEFAULT_DOC: Requests may be collapsed if collapsed_forwarding is on.
7130LOC: Config.accessList.collapsedForwardingAccess
7131DOC_START
7132 Use this directive to restrict collapsed forwarding to a subset of
7133 eligible requests. The directive is checked for regular HTTP
7134 requests, internal revalidation requests, and HTCP/ICP requests.
7135
7136 collapsed_forwarding_access allow|deny [!]aclname ...
7137
7138 This directive cannot force collapsing. It has no effect on
7139 collapsing unless collapsed_forwarding is 'on', and all other
7140 collapsing preconditions are satisfied.
7141
7142 * A denied request will not collapse, and future transactions will
7143 not collapse on it (even if they are allowed to collapse).
7144
7145 * An allowed request may collapse, or future transactions may
7146 collapse on it (provided they are allowed to collapse).
7147
7148 This directive is evaluated before receiving HTTP response headers
7149 and without access to Squid-to-peer connection (if any).
7150
7151 Only fast ACLs are supported.
7152
7153 See also: collapsed_forwarding.
7154DOC_END
7155
daed75a9 7156NAME: shared_transient_entries_limit collapsed_forwarding_shared_entries_limit
8f7dbf74
DD
7157COMMENT: (number of entries)
7158TYPE: int64_t
daed75a9 7159LOC: Config.shared_transient_entries_limit
8f7dbf74
DD
7160DEFAULT: 16384
7161DOC_START
daed75a9
EB
7162 This directive limits the size of a table used for sharing current
7163 transaction information among SMP workers. A table entry stores meta
7164 information about a single cache entry being delivered to Squid
7165 client(s) by one or more SMP workers. A single table entry consumes
7166 less than 128 shared memory bytes.
8f7dbf74 7167
daed75a9
EB
7168 The limit should be significantly larger than the number of
7169 concurrent non-collapsed cachable responses leaving Squid. For a
7170 cache that handles less than 5000 concurrent requests, the default
8f7dbf74
DD
7171 setting of 16384 should be plenty.
7172
daed75a9
EB
7173 Using excessively large values wastes shared memory. Limiting the
7174 table size too much results in hash collisions, leading to lower hit
7175 ratio and missed SMP request collapsing opportunities: Transactions
7176 left without a table entry cannot cache their responses and are
7177 invisible to other concurrent requests for the same resource.
7178
7179 A zero limit is allowed but unsupported. A positive small limit
7180 lowers hit ratio, but zero limit disables a lot of essential
7181 synchronization among SMP workers, leading to HTTP violations (e.g.,
7182 stale hit responses). It also disables shared collapsed forwarding:
7183 A worker becomes unable to collapse its requests on transactions in
7184 other workers, resulting in more trips to the origin server and more
7185 cache thrashing.
8f7dbf74
DD
7186DOC_END
7187
41bd17a4 7188COMMENT_START
7189 TIMEOUTS
7190 -----------------------------------------------------------------------------
7191COMMENT_END
7192
7193NAME: forward_timeout
7194COMMENT: time-units
7195TYPE: time_t
7196LOC: Config.Timeout.forward
7197DEFAULT: 4 minutes
7198DOC_START
7199 This parameter specifies how long Squid should at most attempt in
7200 finding a forwarding path for the request before giving up.
cccac0a2 7201DOC_END
7202
41bd17a4 7203NAME: connect_timeout
7204COMMENT: time-units
7205TYPE: time_t
7206LOC: Config.Timeout.connect
7207DEFAULT: 1 minute
057f5854 7208DOC_START
41bd17a4 7209 This parameter specifies how long to wait for the TCP connect to
7210 the requested server or peer to complete before Squid should
7211 attempt to find another path where to forward the request.
057f5854 7212DOC_END
7213
41bd17a4 7214NAME: peer_connect_timeout
7215COMMENT: time-units
7216TYPE: time_t
7217LOC: Config.Timeout.peer_connect
7218DEFAULT: 30 seconds
cccac0a2 7219DOC_START
41bd17a4 7220 This parameter specifies how long to wait for a pending TCP
7221 connection to a peer cache. The default is 30 seconds. You
7222 may also set different timeout values for individual neighbors
7223 with the 'connect-timeout' option on a 'cache_peer' line.
7224DOC_END
7f7db318 7225
41bd17a4 7226NAME: read_timeout
7227COMMENT: time-units
7228TYPE: time_t
7229LOC: Config.Timeout.read
7230DEFAULT: 15 minutes
7231DOC_START
d5430dc8
AJ
7232 Applied on peer server connections.
7233
7234 After each successful read(), the timeout will be extended by this
41bd17a4 7235 amount. If no data is read again after this amount of time,
d5430dc8
AJ
7236 the request is aborted and logged with ERR_READ_TIMEOUT.
7237
7238 The default is 15 minutes.
41bd17a4 7239DOC_END
cccac0a2 7240
5ef5e5cc
AJ
7241NAME: write_timeout
7242COMMENT: time-units
7243TYPE: time_t
7244LOC: Config.Timeout.write
7245DEFAULT: 15 minutes
7246DOC_START
7247 This timeout is tracked for all connections that have data
7248 available for writing and are waiting for the socket to become
7249 ready. After each successful write, the timeout is extended by
7250 the configured amount. If Squid has data to write but the
7251 connection is not ready for the configured duration, the
7252 transaction associated with the connection is terminated. The
7253 default is 15 minutes.
7254DOC_END
7255
41bd17a4 7256NAME: request_timeout
7257TYPE: time_t
7258LOC: Config.Timeout.request
7259DEFAULT: 5 minutes
7260DOC_START
6b2a2108 7261 How long to wait for complete HTTP request headers after initial
41bd17a4 7262 connection establishment.
7263DOC_END
cccac0a2 7264
3248e962
CT
7265NAME: request_start_timeout
7266TYPE: time_t
7267LOC: Config.Timeout.request_start_timeout
7268DEFAULT: 5 minutes
7269DOC_START
7270 How long to wait for the first request byte after initial
7271 connection establishment.
7272DOC_END
7273
97b32442 7274NAME: client_idle_pconn_timeout persistent_request_timeout
41bd17a4 7275TYPE: time_t
97b32442 7276LOC: Config.Timeout.clientIdlePconn
41bd17a4 7277DEFAULT: 2 minutes
7278DOC_START
7279 How long to wait for the next HTTP request on a persistent
97b32442 7280 client connection after the previous request completes.
41bd17a4 7281DOC_END
cccac0a2 7282
f6e8754a
AR
7283NAME: ftp_client_idle_timeout
7284TYPE: time_t
7285LOC: Config.Timeout.ftpClientIdle
7286DEFAULT: 30 minutes
7287DOC_START
7288 How long to wait for an FTP request on a connection to Squid ftp_port.
7289 Many FTP clients do not deal with idle connection closures well,
7290 necessitating a longer default timeout than client_idle_pconn_timeout
7291 used for incoming HTTP requests.
7292DOC_END
7293
41bd17a4 7294NAME: client_lifetime
7295COMMENT: time-units
7296TYPE: time_t
7297LOC: Config.Timeout.lifetime
7298DEFAULT: 1 day
7299DOC_START
7300 The maximum amount of time a client (browser) is allowed to
7301 remain connected to the cache process. This protects the Cache
7302 from having a lot of sockets (and hence file descriptors) tied up
7303 in a CLOSE_WAIT state from remote clients that go away without
7304 properly shutting down (either because of a network failure or
7305 because of a poor client implementation). The default is one
7306 day, 1440 minutes.
7d90757b 7307
41bd17a4 7308 NOTE: The default value is intended to be much larger than any
7309 client would ever need to be connected to your cache. You
7310 should probably change client_lifetime only as a last resort.
7311 If you seem to have many client connections tying up
7312 filedescriptors, we recommend first tuning the read_timeout,
7313 request_timeout, persistent_request_timeout and quick_abort values.
cccac0a2 7314DOC_END
7315
c5c06f02
CT
7316NAME: pconn_lifetime
7317COMMENT: time-units
7318TYPE: time_t
7319LOC: Config.Timeout.pconnLifetime
7320DEFAULT: 0 seconds
7321DOC_START
7322 Desired maximum lifetime of a persistent connection.
7323 When set, Squid will close a now-idle persistent connection that
7324 exceeded configured lifetime instead of moving the connection into
7325 the idle connection pool (or equivalent). No effect on ongoing/active
7326 transactions. Connection lifetime is the time period from the
7327 connection acceptance or opening time until "now".
9603207d 7328
c5c06f02
CT
7329 This limit is useful in environments with long-lived connections
7330 where Squid configuration or environmental factors change during a
7331 single connection lifetime. If unrestricted, some connections may
7332 last for hours and even days, ignoring those changes that should
7333 have affected their behavior or their existence.
9603207d 7334
c5c06f02
CT
7335 Currently, a new lifetime value supplied via Squid reconfiguration
7336 has no effect on already idle connections unless they become busy.
9603207d 7337
c5c06f02
CT
7338 When set to '0' this limit is not used.
7339DOC_END
7340
41bd17a4 7341NAME: half_closed_clients
7342TYPE: onoff
7343LOC: Config.onoff.half_closed_clients
0c2f5c4f 7344DEFAULT: off
4eb368f9 7345DOC_START
41bd17a4 7346 Some clients may shutdown the sending side of their TCP
7347 connections, while leaving their receiving sides open. Sometimes,
7348 Squid can not tell the difference between a half-closed and a
0c2f5c4f
AJ
7349 fully-closed TCP connection.
7350
7351 By default, Squid will immediately close client connections when
7352 read(2) returns "no more data to read."
7353
abdf1651 7354 Change this option to 'on' and Squid will keep open connections
0c2f5c4f
AJ
7355 until a read(2) or write(2) on the socket returns an error.
7356 This may show some benefits for reverse proxies. But if not
7357 it is recommended to leave OFF.
4eb368f9 7358DOC_END
7359
97b32442 7360NAME: server_idle_pconn_timeout pconn_timeout
41bd17a4 7361TYPE: time_t
97b32442 7362LOC: Config.Timeout.serverIdlePconn
41bd17a4 7363DEFAULT: 1 minute
cccac0a2 7364DOC_START
41bd17a4 7365 Timeout for idle persistent connections to servers and other
7366 proxies.
7367DOC_END
cccac0a2 7368
41bd17a4 7369NAME: ident_timeout
7370TYPE: time_t
7371IFDEF: USE_IDENT
4daaf3cb 7372LOC: Ident::TheConfig.timeout
41bd17a4 7373DEFAULT: 10 seconds
7374DOC_START
7375 Maximum time to wait for IDENT lookups to complete.
cccac0a2 7376
41bd17a4 7377 If this is too high, and you enabled IDENT lookups from untrusted
7378 users, you might be susceptible to denial-of-service by having
7379 many ident requests going at once.
cccac0a2 7380DOC_END
7381
41bd17a4 7382NAME: shutdown_lifetime
7383COMMENT: time-units
7384TYPE: time_t
7385LOC: Config.shutdownLifetime
7386DEFAULT: 30 seconds
cccac0a2 7387DOC_START
41bd17a4 7388 When SIGTERM or SIGHUP is received, the cache is put into
7389 "shutdown pending" mode until all active sockets are closed.
7390 This value is the lifetime to set for all open descriptors
7391 during shutdown mode. Any active clients after this many
7392 seconds will receive a 'timeout' message.
cccac0a2 7393DOC_END
0976f8db 7394
cccac0a2 7395COMMENT_START
7396 ADMINISTRATIVE PARAMETERS
7397 -----------------------------------------------------------------------------
7398COMMENT_END
7399
7400NAME: cache_mgr
7401TYPE: string
7402DEFAULT: webmaster
7403LOC: Config.adminEmail
7404DOC_START
7405 Email-address of local cache manager who will receive
638402dd 7406 mail if the cache dies. The default is "webmaster".
cccac0a2 7407DOC_END
7408
abacf776 7409NAME: mail_from
7410TYPE: string
7411DEFAULT: none
7412LOC: Config.EmailFrom
7413DOC_START
7414 From: email-address for mail sent when the cache dies.
638402dd
AJ
7415 The default is to use 'squid@unique_hostname'.
7416
7417 See also: unique_hostname directive.
abacf776 7418DOC_END
7419
d084bf20 7420NAME: mail_program
7421TYPE: eol
7422DEFAULT: mail
7423LOC: Config.EmailProgram
7424DOC_START
7425 Email program used to send mail if the cache dies.
846a5e31 7426 The default is "mail". The specified program must comply
d084bf20 7427 with the standard Unix mail syntax:
846a5e31 7428 mail-program recipient < mailfile
7429
d084bf20 7430 Optional command line options can be specified.
7431DOC_END
7432
cccac0a2 7433NAME: cache_effective_user
7434TYPE: string
5483d916 7435DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
cccac0a2 7436LOC: Config.effectiveUser
e3d74828 7437DOC_START
7438 If you start Squid as root, it will change its effective/real
7439 UID/GID to the user specified below. The default is to change
5483d916 7440 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
64e288bd 7441 see also; cache_effective_group
e3d74828 7442DOC_END
7443
cccac0a2 7444NAME: cache_effective_group
7445TYPE: string
7446DEFAULT: none
638402dd 7447DEFAULT_DOC: Use system group memberships of the cache_effective_user account
cccac0a2 7448LOC: Config.effectiveGroup
7449DOC_START
64e288bd 7450 Squid sets the GID to the effective user's default group ID
7451 (taken from the password file) and supplementary group list
7452 from the groups membership.
7453
e3d74828 7454 If you want Squid to run with a specific GID regardless of
7455 the group memberships of the effective user then set this
7456 to the group (or GID) you want Squid to run as. When set
64e288bd 7457 all other group privileges of the effective user are ignored
e3d74828 7458 and only this GID is effective. If Squid is not started as
64e288bd 7459 root the user starting Squid MUST be member of the specified
e3d74828 7460 group.
64e288bd 7461
7462 This option is not recommended by the Squid Team.
7463 Our preference is for administrators to configure a secure
7464 user account for squid with UID/GID matching system policies.
cccac0a2 7465DOC_END
7466
d3caee79 7467NAME: httpd_suppress_version_string
7468COMMENT: on|off
7469TYPE: onoff
7470DEFAULT: off
7471LOC: Config.onoff.httpd_suppress_version_string
7472DOC_START
7473 Suppress Squid version string info in HTTP headers and HTML error pages.
7474DOC_END
7475
cccac0a2 7476NAME: visible_hostname
7477TYPE: string
7478LOC: Config.visibleHostname
7479DEFAULT: none
638402dd 7480DEFAULT_DOC: Automatically detect the system host name
cccac0a2 7481DOC_START
7482 If you want to present a special hostname in error messages, etc,
7f7db318 7483 define this. Otherwise, the return value of gethostname()
cccac0a2 7484 will be used. If you have multiple caches in a cluster and
7485 get errors about IP-forwarding you must set them to have individual
7486 names with this setting.
7487DOC_END
7488
cccac0a2 7489NAME: unique_hostname
7490TYPE: string
7491LOC: Config.uniqueHostname
7492DEFAULT: none
638402dd 7493DEFAULT_DOC: Copy the value from visible_hostname
cccac0a2 7494DOC_START
7495 If you want to have multiple machines with the same
7f7db318 7496 'visible_hostname' you must give each machine a different
7497 'unique_hostname' so forwarding loops can be detected.
cccac0a2 7498DOC_END
7499
cccac0a2 7500NAME: hostname_aliases
7501TYPE: wordlist
7502LOC: Config.hostnameAliases
7503DEFAULT: none
7504DOC_START
7f7db318 7505 A list of other DNS names your cache has.
cccac0a2 7506DOC_END
0976f8db 7507
c642c141
AJ
7508NAME: umask
7509TYPE: int
7510LOC: Config.umask
7511DEFAULT: 027
7512DOC_START
7513 Minimum umask which should be enforced while the proxy
7514 is running, in addition to the umask set at startup.
7515
7516 For a traditional octal representation of umasks, start
7517 your value with 0.
7518DOC_END
7519
8d6275c0 7520COMMENT_START
7521 HTTPD-ACCELERATOR OPTIONS
7522 -----------------------------------------------------------------------------
7523COMMENT_END
7524
cccac0a2 7525NAME: httpd_accel_surrogate_id
cccac0a2 7526TYPE: string
b2b40d8c 7527DEFAULT: none
638402dd 7528DEFAULT_DOC: visible_hostname is used if no specific ID is set.
cccac0a2 7529LOC: Config.Accel.surrogate_id
cccac0a2 7530DOC_START
7531 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
7532 need an identification token to allow control targeting. Because
7533 a farm of surrogates may all perform the same tasks, they may share
7534 an identification token.
609d5e06
AJ
7535
7536 When the surrogate is a reverse-proxy, this ID is also
7537 used as cdn-id for CDN-Loop detection (RFC 8586).
cccac0a2 7538DOC_END
7539
7540NAME: http_accel_surrogate_remote
cccac0a2 7541COMMENT: on|off
7542TYPE: onoff
7543DEFAULT: off
7544LOC: Config.onoff.surrogate_is_remote
7545DOC_START
638402dd
AJ
7546 Remote surrogates (such as those in a CDN) honour the header
7547 "Surrogate-Control: no-store-remote".
7548
cccac0a2 7549 Set this to on to have squid behave as a remote surrogate.
7550DOC_END
7551
7552NAME: esi_parser
f41735ea 7553IFDEF: USE_SQUID_ESI
799b66d1 7554COMMENT: libxml2|expat
cccac0a2 7555TYPE: string
7556LOC: ESIParser::Type
799b66d1
AJ
7557DEFAULT: auto
7558DEFAULT_DOC: Selects libxml2 if available at ./configure time or libexpat otherwise.
cccac0a2 7559DOC_START
799b66d1
AJ
7560 Selects the XML parsing library to use when interpreting responses with
7561 Edge Side Includes.
7562
7563 To disable ESI handling completely, ./configure Squid with --disable-esi.
cccac0a2 7564DOC_END
0976f8db 7565
9edd9041 7566COMMENT_START
8d6275c0 7567 DELAY POOL PARAMETERS
9edd9041 7568 -----------------------------------------------------------------------------
7569COMMENT_END
7570
7571NAME: delay_pools
7572TYPE: delay_pool_count
7573DEFAULT: 0
9a0a18de 7574IFDEF: USE_DELAY_POOLS
9edd9041 7575LOC: Config.Delay
7576DOC_START
7577 This represents the number of delay pools to be used. For example,
7578 if you have one class 2 delay pool and one class 3 delays pool, you
7579 have a total of 2 delay pools.
638402dd
AJ
7580
7581 See also delay_parameters, delay_class, delay_access for pool
7582 configuration details.
9edd9041 7583DOC_END
7584
7585NAME: delay_class
7586TYPE: delay_pool_class
7587DEFAULT: none
9a0a18de 7588IFDEF: USE_DELAY_POOLS
9edd9041 7589LOC: Config.Delay
7590DOC_START
7591 This defines the class of each delay pool. There must be exactly one
7592 delay_class line for each delay pool. For example, to define two
7593 delay pools, one of class 2 and one of class 3, the settings above
7594 and here would be:
7595
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AJ
7596 Example:
7597 delay_pools 4 # 4 delay pools
7598 delay_class 1 2 # pool 1 is a class 2 pool
7599 delay_class 2 3 # pool 2 is a class 3 pool
7600 delay_class 3 4 # pool 3 is a class 4 pool
7601 delay_class 4 5 # pool 4 is a class 5 pool
9edd9041 7602
7603 The delay pool classes are:
7604
7605 class 1 Everything is limited by a single aggregate
7606 bucket.
7607
7608 class 2 Everything is limited by a single aggregate
7609 bucket as well as an "individual" bucket chosen
b1fb3348 7610 from bits 25 through 32 of the IPv4 address.
9edd9041 7611
7612 class 3 Everything is limited by a single aggregate
7613 bucket as well as a "network" bucket chosen
7614 from bits 17 through 24 of the IP address and a
7615 "individual" bucket chosen from bits 17 through
b1fb3348 7616 32 of the IPv4 address.
9edd9041 7617
7618 class 4 Everything in a class 3 delay pool, with an
7619 additional limit on a per user basis. This
7620 only takes effect if the username is established
7621 in advance - by forcing authentication in your
7622 http_access rules.
7623
7624 class 5 Requests are grouped according their tag (see
7625 external_acl's tag= reply).
7626
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AJ
7627
7628 Each pool also requires a delay_parameters directive to configure the pool size
7629 and speed limits used whenever the pool is applied to a request. Along with
7630 a set of delay_access directives to determine when it is used.
7631
9edd9041 7632 NOTE: If an IP address is a.b.c.d
7633 -> bits 25 through 32 are "d"
7634 -> bits 17 through 24 are "c"
7635 -> bits 17 through 32 are "c * 256 + d"
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AJ
7636
7637 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
7638 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
638402dd
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7639
7640 This clause only supports fast acl types.
7641 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7642
7643 See also delay_parameters and delay_access.
9edd9041 7644DOC_END
7645
7646NAME: delay_access
7647TYPE: delay_pool_access
7648DEFAULT: none
638402dd 7649DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
9a0a18de 7650IFDEF: USE_DELAY_POOLS
9edd9041 7651LOC: Config.Delay
7652DOC_START
7653 This is used to determine which delay pool a request falls into.
7654
7655 delay_access is sorted per pool and the matching starts with pool 1,
7656 then pool 2, ..., and finally pool N. The first delay pool where the
7657 request is allowed is selected for the request. If it does not allow
7658 the request to any pool then the request is not delayed (default).
7659
7660 For example, if you want some_big_clients in delay
7661 pool 1 and lotsa_little_clients in delay pool 2:
7662
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AJ
7663 delay_access 1 allow some_big_clients
7664 delay_access 1 deny all
7665 delay_access 2 allow lotsa_little_clients
7666 delay_access 2 deny all
7667 delay_access 3 allow authenticated_clients
7668
7669 See also delay_parameters and delay_class.
7670
9edd9041 7671DOC_END
7672
7673NAME: delay_parameters
7674TYPE: delay_pool_rates
7675DEFAULT: none
9a0a18de 7676IFDEF: USE_DELAY_POOLS
9edd9041 7677LOC: Config.Delay
7678DOC_START
7679 This defines the parameters for a delay pool. Each delay pool has
7680 a number of "buckets" associated with it, as explained in the
0b68481a 7681 description of delay_class.
9edd9041 7682
0b68481a 7683 For a class 1 delay pool, the syntax is:
6e7502cc 7684 delay_class pool 1
0b68481a 7685 delay_parameters pool aggregate
9edd9041 7686
7687 For a class 2 delay pool:
6e7502cc 7688 delay_class pool 2
0b68481a 7689 delay_parameters pool aggregate individual
9edd9041 7690
7691 For a class 3 delay pool:
6e7502cc 7692 delay_class pool 3
0b68481a 7693 delay_parameters pool aggregate network individual
9edd9041 7694
7695 For a class 4 delay pool:
6e7502cc 7696 delay_class pool 4
0b68481a 7697 delay_parameters pool aggregate network individual user
9edd9041 7698
7699 For a class 5 delay pool:
6e7502cc 7700 delay_class pool 5
0b68481a 7701 delay_parameters pool tagrate
9edd9041 7702
0b68481a 7703 The option variables are:
9edd9041 7704
7705 pool a pool number - ie, a number between 1 and the
7706 number specified in delay_pools as used in
7707 delay_class lines.
7708
fdb47ac6 7709 aggregate the speed limit parameters for the aggregate bucket
9edd9041 7710 (class 1, 2, 3).
7711
fdb47ac6 7712 individual the speed limit parameters for the individual
9edd9041 7713 buckets (class 2, 3).
7714
fdb47ac6 7715 network the speed limit parameters for the network buckets
9edd9041 7716 (class 3).
7717
fdb47ac6 7718 user the speed limit parameters for the user buckets
9edd9041 7719 (class 4).
7720
fdb47ac6 7721 tagrate the speed limit parameters for the tag buckets
9edd9041 7722 (class 5).
7723
7724 A pair of delay parameters is written restore/maximum, where restore is
7725 the number of bytes (not bits - modem and network speeds are usually
7726 quoted in bits) per second placed into the bucket, and maximum is the
7727 maximum number of bytes which can be in the bucket at any time.
7728
0b68481a
AJ
7729 There must be one delay_parameters line for each delay pool.
7730
7731
9edd9041 7732 For example, if delay pool number 1 is a class 2 delay pool as in the
0b68481a 7733 above example, and is being used to strictly limit each host to 64Kbit/sec
9edd9041 7734 (plus overheads), with no overall limit, the line is:
7735
6e7502cc 7736 delay_parameters 1 none 8000/8000
0b68481a 7737
c3e31a3a 7738 Note that 8 x 8K Byte/sec -> 64K bit/sec.
9edd9041 7739
6e7502cc 7740 Note that the word 'none' is used to represent no limit.
9edd9041 7741
0b68481a 7742
9edd9041 7743 And, if delay pool number 2 is a class 3 delay pool as in the above
0b68481a
AJ
7744 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
7745 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
7746 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
9edd9041 7747 to permit a decent web page to be downloaded at a decent speed
7748 (if the network is not being limited due to overuse) but slow down
7749 large downloads more significantly:
7750
0b68481a
AJ
7751 delay_parameters 2 32000/32000 8000/8000 600/8000
7752
c3e31a3a
AJ
7753 Note that 8 x 32K Byte/sec -> 256K bit/sec.
7754 8 x 8K Byte/sec -> 64K bit/sec.
7755 8 x 600 Byte/sec -> 4800 bit/sec.
9edd9041 7756
9edd9041 7757
7758 Finally, for a class 4 delay pool as in the example - each user will
0b68481a 7759 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
9edd9041 7760
0b68481a 7761 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
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7762
7763
7764 See also delay_class and delay_access.
7765
9edd9041 7766DOC_END
7767
7768NAME: delay_initial_bucket_level
7769COMMENT: (percent, 0-100)
ae870270 7770TYPE: u_short
9edd9041 7771DEFAULT: 50
9a0a18de 7772IFDEF: USE_DELAY_POOLS
9edd9041 7773LOC: Config.Delay.initial
7774DOC_START
7775 The initial bucket percentage is used to determine how much is put
7776 in each bucket when squid starts, is reconfigured, or first notices
7777 a host accessing it (in class 2 and class 3, individual hosts and
7778 networks only have buckets associated with them once they have been
7779 "seen" by squid).
7780DOC_END
7781
b4cd430a
CT
7782COMMENT_START
7783 CLIENT DELAY POOL PARAMETERS
7784 -----------------------------------------------------------------------------
7785COMMENT_END
7786
7787NAME: client_delay_pools
7788TYPE: client_delay_pool_count
7789DEFAULT: 0
9a0a18de 7790IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7791LOC: Config.ClientDelay
7792DOC_START
7793 This option specifies the number of client delay pools used. It must
7794 preceed other client_delay_* options.
7795
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7796 Example:
7797 client_delay_pools 2
7798
7799 See also client_delay_parameters and client_delay_access.
b4cd430a
CT
7800DOC_END
7801
7802NAME: client_delay_initial_bucket_level
7803COMMENT: (percent, 0-no_limit)
ae870270 7804TYPE: u_short
b4cd430a 7805DEFAULT: 50
9a0a18de 7806IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7807LOC: Config.ClientDelay.initial
7808DOC_START
7809 This option determines the initial bucket size as a percentage of
7810 max_bucket_size from client_delay_parameters. Buckets are created
7811 at the time of the "first" connection from the matching IP. Idle
7812 buckets are periodically deleted up.
7813
7814 You can specify more than 100 percent but note that such "oversized"
7815 buckets are not refilled until their size goes down to max_bucket_size
7816 from client_delay_parameters.
7817
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7818 Example:
7819 client_delay_initial_bucket_level 50
b4cd430a
CT
7820DOC_END
7821
7822NAME: client_delay_parameters
7823TYPE: client_delay_pool_rates
7824DEFAULT: none
9a0a18de 7825IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7826LOC: Config.ClientDelay
7827DOC_START
7828
7829 This option configures client-side bandwidth limits using the
7830 following format:
7831
7832 client_delay_parameters pool speed_limit max_bucket_size
7833
7834 pool is an integer ID used for client_delay_access matching.
7835
7836 speed_limit is bytes added to the bucket per second.
7837
7838 max_bucket_size is the maximum size of a bucket, enforced after any
7839 speed_limit additions.
7840
7841 Please see the delay_parameters option for more information and
7842 examples.
7843
638402dd
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7844 Example:
7845 client_delay_parameters 1 1024 2048
7846 client_delay_parameters 2 51200 16384
7847
7848 See also client_delay_access.
7849
b4cd430a
CT
7850DOC_END
7851
7852NAME: client_delay_access
7853TYPE: client_delay_pool_access
7854DEFAULT: none
638402dd 7855DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
9a0a18de 7856IFDEF: USE_DELAY_POOLS
b4cd430a
CT
7857LOC: Config.ClientDelay
7858DOC_START
b4cd430a
CT
7859 This option determines the client-side delay pool for the
7860 request:
7861
7862 client_delay_access pool_ID allow|deny acl_name
7863
7864 All client_delay_access options are checked in their pool ID
7865 order, starting with pool 1. The first checked pool with allowed
7866 request is selected for the request. If no ACL matches or there
7867 are no client_delay_access options, the request bandwidth is not
7868 limited.
7869
7870 The ACL-selected pool is then used to find the
7871 client_delay_parameters for the request. Client-side pools are
7872 not used to aggregate clients. Clients are always aggregated
7873 based on their source IP addresses (one bucket per source IP).
7874
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7875 This clause only supports fast acl types.
7876 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7877 Additionally, only the client TCP connection details are available.
7878 ACLs testing HTTP properties will not work.
7879
b4cd430a
CT
7880 Please see delay_access for more examples.
7881
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7882 Example:
7883 client_delay_access 1 allow low_rate_network
7884 client_delay_access 2 allow vips_network
7885
7886
7887 See also client_delay_parameters and client_delay_pools.
b4cd430a
CT
7888DOC_END
7889
b27668ec
EB
7890NAME: response_delay_pool
7891TYPE: response_delay_pool_parameters
7892DEFAULT: none
7893IFDEF: USE_DELAY_POOLS
7894LOC: Config.MessageDelay
7895DOC_START
7896 This option configures client response bandwidth limits using the
7897 following format:
7898
7899 response_delay_pool name [option=value] ...
7900
7901 name the response delay pool name
7902
7903 available options:
7904
7905 individual-restore The speed limit of an individual
7906 bucket(bytes/s). To be used in conjunction
7907 with 'individual-maximum'.
7908
7909 individual-maximum The maximum number of bytes which can
7910 be placed into the individual bucket. To be used
7911 in conjunction with 'individual-restore'.
7912
7913 aggregate-restore The speed limit for the aggregate
7914 bucket(bytes/s). To be used in conjunction with
7915 'aggregate-maximum'.
7916
7917 aggregate-maximum The maximum number of bytes which can
7918 be placed into the aggregate bucket. To be used
7919 in conjunction with 'aggregate-restore'.
7920
7921 initial-bucket-level The initial bucket size as a percentage
7922 of individual-maximum.
7923
7924 Individual and(or) aggregate bucket options may not be specified,
7925 meaning no individual and(or) aggregate speed limitation.
7926 See also response_delay_pool_access and delay_parameters for
7927 terminology details.
7928DOC_END
7929
7930NAME: response_delay_pool_access
7931TYPE: response_delay_pool_access
7932DEFAULT: none
7933DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
7934IFDEF: USE_DELAY_POOLS
7935LOC: Config.MessageDelay
7936DOC_START
7937 Determines whether a specific named response delay pool is used
7938 for the transaction. The syntax for this directive is:
7939
7940 response_delay_pool_access pool_name allow|deny acl_name
7941
7942 All response_delay_pool_access options are checked in the order
7943 they appear in this configuration file. The first rule with a
7944 matching ACL wins. If (and only if) an "allow" rule won, Squid
7945 assigns the response to the corresponding named delay pool.
7946DOC_END
7947
cccac0a2 7948COMMENT_START
8d6275c0 7949 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
cccac0a2 7950 -----------------------------------------------------------------------------
7951COMMENT_END
7952
8d6275c0 7953NAME: wccp_router
7954TYPE: address
7955LOC: Config.Wccp.router
0eb08770 7956DEFAULT: any_addr
638402dd 7957DEFAULT_DOC: WCCP disabled.
8d6275c0 7958IFDEF: USE_WCCP
e313ab0a
AJ
7959DOC_START
7960 Use this option to define your WCCP ``home'' router for
7961 Squid.
7962
7963 wccp_router supports a single WCCP(v1) router
7964
7965 wccp2_router supports multiple WCCPv2 routers
7966
7967 only one of the two may be used at the same time and defines
7968 which version of WCCP to use.
7969DOC_END
df2eec10 7970
8d6275c0 7971NAME: wccp2_router
9fb4efad 7972TYPE: IpAddress_list
8d6275c0 7973LOC: Config.Wccp2.router
cccac0a2 7974DEFAULT: none
638402dd 7975DEFAULT_DOC: WCCPv2 disabled.
8d6275c0 7976IFDEF: USE_WCCPv2
cccac0a2 7977DOC_START
8d6275c0 7978 Use this option to define your WCCP ``home'' router for
7979 Squid.
cccac0a2 7980
8d6275c0 7981 wccp_router supports a single WCCP(v1) router
cccac0a2 7982
8d6275c0 7983 wccp2_router supports multiple WCCPv2 routers
cccac0a2 7984
8d6275c0 7985 only one of the two may be used at the same time and defines
7986 which version of WCCP to use.
7987DOC_END
7988
7989NAME: wccp_version
cccac0a2 7990TYPE: int
8d6275c0 7991LOC: Config.Wccp.version
7992DEFAULT: 4
7993IFDEF: USE_WCCP
cccac0a2 7994DOC_START
8d6275c0 7995 This directive is only relevant if you need to set up WCCP(v1)
7996 to some very old and end-of-life Cisco routers. In all other
7997 setups it must be left unset or at the default setting.
7998 It defines an internal version in the WCCP(v1) protocol,
7999 with version 4 being the officially documented protocol.
cccac0a2 8000
8d6275c0 8001 According to some users, Cisco IOS 11.2 and earlier only
8002 support WCCP version 3. If you're using that or an earlier
8003 version of IOS, you may need to change this value to 3, otherwise
8004 do not specify this parameter.
cccac0a2 8005DOC_END
8006
8d6275c0 8007NAME: wccp2_rebuild_wait
8008TYPE: onoff
8009LOC: Config.Wccp2.rebuildwait
8010DEFAULT: on
8011IFDEF: USE_WCCPv2
8012DOC_START
8013 If this is enabled Squid will wait for the cache dir rebuild to finish
8014 before sending the first wccp2 HereIAm packet
8015DOC_END
cccac0a2 8016
8d6275c0 8017NAME: wccp2_forwarding_method
e313ab0a 8018TYPE: wccp2_method
8d6275c0 8019LOC: Config.Wccp2.forwarding_method
451c4786 8020DEFAULT: gre
8d6275c0 8021IFDEF: USE_WCCPv2
cccac0a2 8022DOC_START
699acd19 8023 WCCP2 allows the setting of forwarding methods between the
8d6275c0 8024 router/switch and the cache. Valid values are as follows:
cccac0a2 8025
451c4786
AJ
8026 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
8027 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
cccac0a2 8028
8d6275c0 8029 Currently (as of IOS 12.4) cisco routers only support GRE.
8030 Cisco switches only support the L2 redirect assignment method.
cccac0a2 8031DOC_END
8032
8d6275c0 8033NAME: wccp2_return_method
e313ab0a 8034TYPE: wccp2_method
8d6275c0 8035LOC: Config.Wccp2.return_method
451c4786 8036DEFAULT: gre
8d6275c0 8037IFDEF: USE_WCCPv2
cccac0a2 8038DOC_START
699acd19 8039 WCCP2 allows the setting of return methods between the
8d6275c0 8040 router/switch and the cache for packets that the cache
8041 decides not to handle. Valid values are as follows:
cccac0a2 8042
451c4786
AJ
8043 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
8044 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
cccac0a2 8045
8d6275c0 8046 Currently (as of IOS 12.4) cisco routers only support GRE.
8047 Cisco switches only support the L2 redirect assignment.
cccac0a2 8048
699acd19 8049 If the "ip wccp redirect exclude in" command has been
8d6275c0 8050 enabled on the cache interface, then it is still safe for
8051 the proxy server to use a l2 redirect method even if this
8052 option is set to GRE.
cccac0a2 8053DOC_END
8054
8d6275c0 8055NAME: wccp2_assignment_method
451c4786 8056TYPE: wccp2_amethod
8d6275c0 8057LOC: Config.Wccp2.assignment_method
451c4786 8058DEFAULT: hash
8d6275c0 8059IFDEF: USE_WCCPv2
cccac0a2 8060DOC_START
8d6275c0 8061 WCCP2 allows the setting of methods to assign the WCCP hash
8062 Valid values are as follows:
cccac0a2 8063
451c4786 8064 hash - Hash assignment
bb7a1781 8065 mask - Mask assignment
cccac0a2 8066
8d6275c0 8067 As a general rule, cisco routers support the hash assignment method
8068 and cisco switches support the mask assignment method.
8069DOC_END
cccac0a2 8070
8d6275c0 8071NAME: wccp2_service
8072TYPE: wccp2_service
8073LOC: Config.Wccp2.info
8d6275c0 8074DEFAULT_IF_NONE: standard 0
638402dd 8075DEFAULT_DOC: Use the 'web-cache' standard service.
8d6275c0 8076IFDEF: USE_WCCPv2
8077DOC_START
8078 WCCP2 allows for multiple traffic services. There are two
8079 types: "standard" and "dynamic". The standard type defines
8080 one service id - http (id 0). The dynamic service ids can be from
8081 51 to 255 inclusive. In order to use a dynamic service id
8082 one must define the type of traffic to be redirected; this is done
8083 using the wccp2_service_info option.
8084
8085 The "standard" type does not require a wccp2_service_info option,
8086 just specifying the service id will suffice.
8087
8088 MD5 service authentication can be enabled by adding
8089 "password=<password>" to the end of this service declaration.
8090
8091 Examples:
8092
8093 wccp2_service standard 0 # for the 'web-cache' standard service
8094 wccp2_service dynamic 80 # a dynamic service type which will be
8095 # fleshed out with subsequent options.
8096 wccp2_service standard 0 password=foo
8d6275c0 8097DOC_END
8098
8099NAME: wccp2_service_info
8100TYPE: wccp2_service_info
8101LOC: Config.Wccp2.info
8102DEFAULT: none
8103IFDEF: USE_WCCPv2
8104DOC_START
8105 Dynamic WCCPv2 services require further information to define the
8106 traffic you wish to have diverted.
8107
8108 The format is:
8109
8110 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
8111 priority=<priority> ports=<port>,<port>..
8112
8113 The relevant WCCPv2 flags:
8114 + src_ip_hash, dst_ip_hash
005fe566 8115 + source_port_hash, dst_port_hash
8d6275c0 8116 + src_ip_alt_hash, dst_ip_alt_hash
8117 + src_port_alt_hash, dst_port_alt_hash
8118 + ports_source
8119
8120 The port list can be one to eight entries.
8121
8122 Example:
8123
8124 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
8125 priority=240 ports=80
8126
8127 Note: the service id must have been defined by a previous
8128 'wccp2_service dynamic <id>' entry.
8129DOC_END
8130
8131NAME: wccp2_weight
8132TYPE: int
8133LOC: Config.Wccp2.weight
8134DEFAULT: 10000
8135IFDEF: USE_WCCPv2
8136DOC_START
8137 Each cache server gets assigned a set of the destination
8138 hash proportional to their weight.
8139DOC_END
8140
8141NAME: wccp_address
8142TYPE: address
8143LOC: Config.Wccp.address
8144DEFAULT: 0.0.0.0
638402dd 8145DEFAULT_DOC: Address selected by the operating system.
8d6275c0 8146IFDEF: USE_WCCP
638402dd 8147DOC_START
dfd5ce0a 8148 Use this option if you require WCCP(v1) to use a specific
638402dd
AJ
8149 interface address.
8150
8151 The default behavior is to not bind to any specific address.
8152DOC_END
df2eec10 8153
8d6275c0 8154NAME: wccp2_address
8155TYPE: address
8156LOC: Config.Wccp2.address
8157DEFAULT: 0.0.0.0
638402dd 8158DEFAULT_DOC: Address selected by the operating system.
8d6275c0 8159IFDEF: USE_WCCPv2
8160DOC_START
dfd5ce0a 8161 Use this option if you require WCCPv2 to use a specific
8d6275c0 8162 interface address.
8163
8164 The default behavior is to not bind to any specific address.
8165DOC_END
8166
8167COMMENT_START
8168 PERSISTENT CONNECTION HANDLING
8169 -----------------------------------------------------------------------------
8170
8171 Also see "pconn_timeout" in the TIMEOUTS section
8172COMMENT_END
8173
8174NAME: client_persistent_connections
8175TYPE: onoff
8176LOC: Config.onoff.client_pconns
8177DEFAULT: on
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8178DOC_START
8179 Persistent connection support for clients.
8180 Squid uses persistent connections (when allowed). You can use
8181 this option to disable persistent connections with clients.
8182DOC_END
8d6275c0 8183
8184NAME: server_persistent_connections
8185TYPE: onoff
8186LOC: Config.onoff.server_pconns
8187DEFAULT: on
8188DOC_START
638402dd
AJ
8189 Persistent connection support for servers.
8190 Squid uses persistent connections (when allowed). You can use
8191 this option to disable persistent connections with servers.
8d6275c0 8192DOC_END
8193
8194NAME: persistent_connection_after_error
8195TYPE: onoff
8196LOC: Config.onoff.error_pconns
0fccfb7f 8197DEFAULT: on
8d6275c0 8198DOC_START
8199 With this directive the use of persistent connections after
8200 HTTP errors can be disabled. Useful if you have clients
8201 who fail to handle errors on persistent connections proper.
8202DOC_END
8203
8204NAME: detect_broken_pconn
8205TYPE: onoff
8206LOC: Config.onoff.detect_broken_server_pconns
8207DEFAULT: off
8208DOC_START
8209 Some servers have been found to incorrectly signal the use
8210 of HTTP/1.0 persistent connections even on replies not
8211 compatible, causing significant delays. This server problem
8212 has mostly been seen on redirects.
8213
8214 By enabling this directive Squid attempts to detect such
8215 broken replies and automatically assume the reply is finished
8216 after 10 seconds timeout.
8217DOC_END
8218
8219COMMENT_START
8220 CACHE DIGEST OPTIONS
8221 -----------------------------------------------------------------------------
8222COMMENT_END
8223
8224NAME: digest_generation
8225IFDEF: USE_CACHE_DIGESTS
8226TYPE: onoff
8227LOC: Config.onoff.digest_generation
8228DEFAULT: on
8229DOC_START
8230 This controls whether the server will generate a Cache Digest
8231 of its contents. By default, Cache Digest generation is
13e917b5 8232 enabled if Squid is compiled with --enable-cache-digests defined.
8d6275c0 8233DOC_END
8234
8235NAME: digest_bits_per_entry
8236IFDEF: USE_CACHE_DIGESTS
8237TYPE: int
8238LOC: Config.digest.bits_per_entry
8239DEFAULT: 5
8240DOC_START
8241 This is the number of bits of the server's Cache Digest which
8242 will be associated with the Digest entry for a given HTTP
8243 Method and URL (public key) combination. The default is 5.
8244DOC_END
8245
8246NAME: digest_rebuild_period
8247IFDEF: USE_CACHE_DIGESTS
8248COMMENT: (seconds)
8249TYPE: time_t
8250LOC: Config.digest.rebuild_period
8251DEFAULT: 1 hour
8252DOC_START
749ceff8 8253 This is the wait time between Cache Digest rebuilds.
8d6275c0 8254DOC_END
8255
8256NAME: digest_rewrite_period
8257COMMENT: (seconds)
8258IFDEF: USE_CACHE_DIGESTS
8259TYPE: time_t
8260LOC: Config.digest.rewrite_period
8261DEFAULT: 1 hour
8262DOC_START
749ceff8 8263 This is the wait time between Cache Digest writes to
8d6275c0 8264 disk.
8265DOC_END
8266
8267NAME: digest_swapout_chunk_size
8268COMMENT: (bytes)
8269TYPE: b_size_t
8270IFDEF: USE_CACHE_DIGESTS
8271LOC: Config.digest.swapout_chunk_size
8272DEFAULT: 4096 bytes
8273DOC_START
8274 This is the number of bytes of the Cache Digest to write to
8275 disk at a time. It defaults to 4096 bytes (4KB), the Squid
8276 default swap page.
8277DOC_END
8278
8279NAME: digest_rebuild_chunk_percentage
8280COMMENT: (percent, 0-100)
8281IFDEF: USE_CACHE_DIGESTS
8282TYPE: int
8283LOC: Config.digest.rebuild_chunk_percentage
8284DEFAULT: 10
8285DOC_START
8286 This is the percentage of the Cache Digest to be scanned at a
8287 time. By default it is set to 10% of the Cache Digest.
8288DOC_END
8289
1db9eacd 8290COMMENT_START
5473c134 8291 SNMP OPTIONS
1db9eacd 8292 -----------------------------------------------------------------------------
8293COMMENT_END
8294
5473c134 8295NAME: snmp_port
ae870270 8296TYPE: u_short
5473c134 8297LOC: Config.Port.snmp
87630341 8298DEFAULT: 0
638402dd 8299DEFAULT_DOC: SNMP disabled.
5473c134 8300IFDEF: SQUID_SNMP
8d6275c0 8301DOC_START
87630341 8302 The port number where Squid listens for SNMP requests. To enable
8303 SNMP support set this to a suitable port number. Port number
8304 3401 is often used for the Squid SNMP agent. By default it's
8305 set to "0" (disabled)
e0855596
AJ
8306
8307 Example:
8308 snmp_port 3401
8d6275c0 8309DOC_END
8310
5473c134 8311NAME: snmp_access
8312TYPE: acl_access
8313LOC: Config.accessList.snmp
638402dd
AJ
8314DEFAULT: none
8315DEFAULT_DOC: Deny, unless rules exist in squid.conf.
5473c134 8316IFDEF: SQUID_SNMP
8d6275c0 8317DOC_START
5473c134 8318 Allowing or denying access to the SNMP port.
8d6275c0 8319
5473c134 8320 All access to the agent is denied by default.
8321 usage:
8d6275c0 8322
5473c134 8323 snmp_access allow|deny [!]aclname ...
8d6275c0 8324
b3567eb5
FC
8325 This clause only supports fast acl types.
8326 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
638402dd 8327
5473c134 8328Example:
8329 snmp_access allow snmppublic localhost
8330 snmp_access deny all
cccac0a2 8331DOC_END
8332
5473c134 8333NAME: snmp_incoming_address
8334TYPE: address
8335LOC: Config.Addrs.snmp_incoming
0eb08770 8336DEFAULT: any_addr
638402dd 8337DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
5473c134 8338IFDEF: SQUID_SNMP
638402dd
AJ
8339DOC_START
8340 Just like 'udp_incoming_address', but for the SNMP port.
8341
8342 snmp_incoming_address is used for the SNMP socket receiving
8343 messages from SNMP agents.
8344
8345 The default snmp_incoming_address is to listen on all
8346 available network interfaces.
8347DOC_END
df2eec10 8348
5473c134 8349NAME: snmp_outgoing_address
8350TYPE: address
8351LOC: Config.Addrs.snmp_outgoing
0eb08770 8352DEFAULT: no_addr
638402dd 8353DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
5473c134 8354IFDEF: SQUID_SNMP
cccac0a2 8355DOC_START
638402dd 8356 Just like 'udp_outgoing_address', but for the SNMP port.
cccac0a2 8357
5473c134 8358 snmp_outgoing_address is used for SNMP packets returned to SNMP
8359 agents.
cccac0a2 8360
0eb08770
HN
8361 If snmp_outgoing_address is not set it will use the same socket
8362 as snmp_incoming_address. Only change this if you want to have
8363 SNMP replies sent using another address than where this Squid
8364 listens for SNMP queries.
cccac0a2 8365
5473c134 8366 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
638402dd 8367 the same value since they both use the same port.
cccac0a2 8368DOC_END
8369
5473c134 8370COMMENT_START
8371 ICP OPTIONS
8372 -----------------------------------------------------------------------------
8373COMMENT_END
8374
8375NAME: icp_port udp_port
ae870270 8376TYPE: u_short
5473c134 8377DEFAULT: 0
638402dd 8378DEFAULT_DOC: ICP disabled.
5473c134 8379LOC: Config.Port.icp
cccac0a2 8380DOC_START
5473c134 8381 The port number where Squid sends and receives ICP queries to
8382 and from neighbor caches. The standard UDP port for ICP is 3130.
e0855596
AJ
8383
8384 Example:
8385 icp_port @DEFAULT_ICP_PORT@
cccac0a2 8386DOC_END
8387
5473c134 8388NAME: htcp_port
8389IFDEF: USE_HTCP
ae870270 8390TYPE: u_short
87630341 8391DEFAULT: 0
638402dd 8392DEFAULT_DOC: HTCP disabled.
5473c134 8393LOC: Config.Port.htcp
cccac0a2 8394DOC_START
5473c134 8395 The port number where Squid sends and receives HTCP queries to
87630341 8396 and from neighbor caches. To turn it on you want to set it to
638402dd 8397 4827.
e0855596
AJ
8398
8399 Example:
8400 htcp_port 4827
cccac0a2 8401DOC_END
8402
8403NAME: log_icp_queries
8404COMMENT: on|off
8405TYPE: onoff
8406DEFAULT: on
8407LOC: Config.onoff.log_udp
8408DOC_START
8409 If set, ICP queries are logged to access.log. You may wish
8410 do disable this if your ICP load is VERY high to speed things
8411 up or to simplify log analysis.
8412DOC_END
8413
5473c134 8414NAME: udp_incoming_address
8415TYPE: address
8416LOC:Config.Addrs.udp_incoming
0eb08770 8417DEFAULT: any_addr
638402dd 8418DEFAULT_DOC: Accept packets from all machine interfaces.
8524d4b2 8419DOC_START
8420 udp_incoming_address is used for UDP packets received from other
8421 caches.
8422
8423 The default behavior is to not bind to any specific address.
8424
8425 Only change this if you want to have all UDP queries received on
8426 a specific interface/address.
8427
8428 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
8429 modules. Altering it will affect all of them in the same manner.
8430
8431 see also; udp_outgoing_address
8432
8433 NOTE, udp_incoming_address and udp_outgoing_address can not
8434 have the same value since they both use the same port.
8435DOC_END
cccac0a2 8436
5473c134 8437NAME: udp_outgoing_address
8438TYPE: address
8439LOC: Config.Addrs.udp_outgoing
0eb08770 8440DEFAULT: no_addr
638402dd 8441DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
cccac0a2 8442DOC_START
8524d4b2 8443 udp_outgoing_address is used for UDP packets sent out to other
5473c134 8444 caches.
cccac0a2 8445
5473c134 8446 The default behavior is to not bind to any specific address.
cccac0a2 8447
8524d4b2 8448 Instead it will use the same socket as udp_incoming_address.
8449 Only change this if you want to have UDP queries sent using another
8450 address than where this Squid listens for UDP queries from other
5473c134 8451 caches.
8452
8524d4b2 8453 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
8454 modules. Altering it will affect all of them in the same manner.
8455
8456 see also; udp_incoming_address
8457
5473c134 8458 NOTE, udp_incoming_address and udp_outgoing_address can not
8524d4b2 8459 have the same value since they both use the same port.
cccac0a2 8460DOC_END
8461
3d1e3e43 8462NAME: icp_hit_stale
8463COMMENT: on|off
8464TYPE: onoff
8465DEFAULT: off
8466LOC: Config.onoff.icp_hit_stale
8467DOC_START
8468 If you want to return ICP_HIT for stale cache objects, set this
8469 option to 'on'. If you have sibling relationships with caches
8470 in other administrative domains, this should be 'off'. If you only
8471 have sibling relationships with caches under your control,
8472 it is probably okay to set this to 'on'.
8473 If set to 'on', your siblings should use the option "allow-miss"
8474 on their cache_peer lines for connecting to you.
8475DOC_END
8476
5473c134 8477NAME: minimum_direct_hops
cccac0a2 8478TYPE: int
5473c134 8479DEFAULT: 4
8480LOC: Config.minDirectHops
cccac0a2 8481DOC_START
5473c134 8482 If using the ICMP pinging stuff, do direct fetches for sites
8483 which are no more than this many hops away.
cccac0a2 8484DOC_END
8485
5473c134 8486NAME: minimum_direct_rtt
638402dd 8487COMMENT: (msec)
5473c134 8488TYPE: int
8489DEFAULT: 400
8490LOC: Config.minDirectRtt
cccac0a2 8491DOC_START
5473c134 8492 If using the ICMP pinging stuff, do direct fetches for sites
8493 which are no more than this many rtt milliseconds away.
cccac0a2 8494DOC_END
8495
cccac0a2 8496NAME: netdb_low
8497TYPE: int
8498DEFAULT: 900
8499LOC: Config.Netdb.low
638402dd
AJ
8500DOC_START
8501 The low water mark for the ICMP measurement database.
8502
8503 Note: high watermark controlled by netdb_high directive.
8504
8505 These watermarks are counts, not percents. The defaults are
8506 (low) 900 and (high) 1000. When the high water mark is
8507 reached, database entries will be deleted until the low
8508 mark is reached.
8509DOC_END
cccac0a2 8510
8511NAME: netdb_high
8512TYPE: int
8513DEFAULT: 1000
8514LOC: Config.Netdb.high
8515DOC_START
638402dd
AJ
8516 The high water mark for the ICMP measurement database.
8517
8518 Note: low watermark controlled by netdb_low directive.
8519
8520 These watermarks are counts, not percents. The defaults are
8521 (low) 900 and (high) 1000. When the high water mark is
8522 reached, database entries will be deleted until the low
8523 mark is reached.
cccac0a2 8524DOC_END
8525
cccac0a2 8526NAME: netdb_ping_period
8527TYPE: time_t
8528LOC: Config.Netdb.period
8529DEFAULT: 5 minutes
8530DOC_START
8531 The minimum period for measuring a site. There will be at
8532 least this much delay between successive pings to the same
8533 network. The default is five minutes.
8534DOC_END
8535
cccac0a2 8536NAME: query_icmp
8537COMMENT: on|off
8538TYPE: onoff
8539DEFAULT: off
8540LOC: Config.onoff.query_icmp
8541DOC_START
8542 If you want to ask your peers to include ICMP data in their ICP
8543 replies, enable this option.
8544
8545 If your peer has configured Squid (during compilation) with
7f7db318 8546 '--enable-icmp' that peer will send ICMP pings to origin server
8547 sites of the URLs it receives. If you enable this option the
cccac0a2 8548 ICP replies from that peer will include the ICMP data (if available).
8549 Then, when choosing a parent cache, Squid will choose the parent with
8550 the minimal RTT to the origin server. When this happens, the
8551 hierarchy field of the access.log will be
8552 "CLOSEST_PARENT_MISS". This option is off by default.
8553DOC_END
8554
8555NAME: test_reachability
8556COMMENT: on|off
8557TYPE: onoff
8558DEFAULT: off
8559LOC: Config.onoff.test_reachability
8560DOC_START
8561 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
8562 instead of ICP_MISS if the target host is NOT in the ICMP
8563 database, or has a zero RTT.
8564DOC_END
8565
5473c134 8566NAME: icp_query_timeout
8567COMMENT: (msec)
8568DEFAULT: 0
638402dd 8569DEFAULT_DOC: Dynamic detection.
5473c134 8570TYPE: int
8571LOC: Config.Timeout.icp_query
4c3ef9b2 8572DOC_START
5473c134 8573 Normally Squid will automatically determine an optimal ICP
8574 query timeout value based on the round-trip-time of recent ICP
8575 queries. If you want to override the value determined by
8576 Squid, set this 'icp_query_timeout' to a non-zero value. This
8577 value is specified in MILLISECONDS, so, to use a 2-second
8578 timeout (the old default), you would write:
4c3ef9b2 8579
5473c134 8580 icp_query_timeout 2000
4c3ef9b2 8581DOC_END
8582
5473c134 8583NAME: maximum_icp_query_timeout
8584COMMENT: (msec)
8585DEFAULT: 2000
8586TYPE: int
8587LOC: Config.Timeout.icp_query_max
cccac0a2 8588DOC_START
5473c134 8589 Normally the ICP query timeout is determined dynamically. But
8590 sometimes it can lead to very large values (say 5 seconds).
8591 Use this option to put an upper limit on the dynamic timeout
8592 value. Do NOT use this option to always use a fixed (instead
8593 of a dynamic) timeout value. To set a fixed timeout see the
8594 'icp_query_timeout' directive.
cccac0a2 8595DOC_END
8596
5473c134 8597NAME: minimum_icp_query_timeout
8598COMMENT: (msec)
8599DEFAULT: 5
8600TYPE: int
8601LOC: Config.Timeout.icp_query_min
cccac0a2 8602DOC_START
5473c134 8603 Normally the ICP query timeout is determined dynamically. But
8604 sometimes it can lead to very small timeouts, even lower than
8605 the normal latency variance on your link due to traffic.
8606 Use this option to put an lower limit on the dynamic timeout
8607 value. Do NOT use this option to always use a fixed (instead
8608 of a dynamic) timeout value. To set a fixed timeout see the
8609 'icp_query_timeout' directive.
cccac0a2 8610DOC_END
8611
5473c134 8612NAME: background_ping_rate
8613COMMENT: time-units
8614TYPE: time_t
8615DEFAULT: 10 seconds
8616LOC: Config.backgroundPingRate
cccac0a2 8617DOC_START
5473c134 8618 Controls how often the ICP pings are sent to siblings that
8619 have background-ping set.
cccac0a2 8620DOC_END
8621
5473c134 8622COMMENT_START
8623 MULTICAST ICP OPTIONS
8624 -----------------------------------------------------------------------------
8625COMMENT_END
8626
8627NAME: mcast_groups
8628TYPE: wordlist
8629LOC: Config.mcast_group_list
8c01ada0 8630DEFAULT: none
8631DOC_START
5473c134 8632 This tag specifies a list of multicast groups which your server
8633 should join to receive multicasted ICP queries.
8c01ada0 8634
5473c134 8635 NOTE! Be very careful what you put here! Be sure you
8636 understand the difference between an ICP _query_ and an ICP
8637 _reply_. This option is to be set only if you want to RECEIVE
8638 multicast queries. Do NOT set this option to SEND multicast
8639 ICP (use cache_peer for that). ICP replies are always sent via
8640 unicast, so this option does not affect whether or not you will
8641 receive replies from multicast group members.
8c01ada0 8642
5473c134 8643 You must be very careful to NOT use a multicast address which
8644 is already in use by another group of caches.
8c01ada0 8645
5473c134 8646 If you are unsure about multicast, please read the Multicast
8647 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
8c01ada0 8648
5473c134 8649 Usage: mcast_groups 239.128.16.128 224.0.1.20
8c01ada0 8650
5473c134 8651 By default, Squid doesn't listen on any multicast groups.
8652DOC_END
8c01ada0 8653
5473c134 8654NAME: mcast_miss_addr
8655IFDEF: MULTICAST_MISS_STREAM
8656TYPE: address
8657LOC: Config.mcast_miss.addr
0eb08770 8658DEFAULT: no_addr
638402dd 8659DEFAULT_DOC: disabled.
5473c134 8660DOC_START
8661 If you enable this option, every "cache miss" URL will
8662 be sent out on the specified multicast address.
cccac0a2 8663
5473c134 8664 Do not enable this option unless you are are absolutely
8665 certain you understand what you are doing.
cccac0a2 8666DOC_END
8667
5473c134 8668NAME: mcast_miss_ttl
8669IFDEF: MULTICAST_MISS_STREAM
ae870270 8670TYPE: u_short
5473c134 8671LOC: Config.mcast_miss.ttl
8672DEFAULT: 16
cccac0a2 8673DOC_START
5473c134 8674 This is the time-to-live value for packets multicasted
8675 when multicasting off cache miss URLs is enabled. By
8676 default this is set to 'site scope', i.e. 16.
8677DOC_END
cccac0a2 8678
5473c134 8679NAME: mcast_miss_port
8680IFDEF: MULTICAST_MISS_STREAM
ae870270 8681TYPE: u_short
5473c134 8682LOC: Config.mcast_miss.port
8683DEFAULT: 3135
8684DOC_START
8685 This is the port number to be used in conjunction with
8686 'mcast_miss_addr'.
8687DOC_END
cccac0a2 8688
5473c134 8689NAME: mcast_miss_encode_key
8690IFDEF: MULTICAST_MISS_STREAM
8691TYPE: string
8692LOC: Config.mcast_miss.encode_key
8693DEFAULT: XXXXXXXXXXXXXXXX
8694DOC_START
8695 The URLs that are sent in the multicast miss stream are
8696 encrypted. This is the encryption key.
8697DOC_END
8c01ada0 8698
5473c134 8699NAME: mcast_icp_query_timeout
8700COMMENT: (msec)
8701DEFAULT: 2000
8702TYPE: int
8703LOC: Config.Timeout.mcast_icp_query
8704DOC_START
8705 For multicast peers, Squid regularly sends out ICP "probes" to
8706 count how many other peers are listening on the given multicast
8707 address. This value specifies how long Squid should wait to
8708 count all the replies. The default is 2000 msec, or 2
8709 seconds.
cccac0a2 8710DOC_END
8711
5473c134 8712COMMENT_START
8713 INTERNAL ICON OPTIONS
8714 -----------------------------------------------------------------------------
8715COMMENT_END
8716
cccac0a2 8717NAME: icon_directory
8718TYPE: string
8719LOC: Config.icons.directory
8720DEFAULT: @DEFAULT_ICON_DIR@
8721DOC_START
8722 Where the icons are stored. These are normally kept in
8723 @DEFAULT_ICON_DIR@
8724DOC_END
8725
f024c970 8726NAME: global_internal_static
8727TYPE: onoff
8728LOC: Config.onoff.global_internal_static
8729DEFAULT: on
8730DOC_START
8731 This directive controls is Squid should intercept all requests for
8732 /squid-internal-static/ no matter which host the URL is requesting
8733 (default on setting), or if nothing special should be done for
8734 such URLs (off setting). The purpose of this directive is to make
8735 icons etc work better in complex cache hierarchies where it may
8736 not always be possible for all corners in the cache mesh to reach
8737 the server generating a directory listing.
8738DOC_END
8739
5473c134 8740NAME: short_icon_urls
8741TYPE: onoff
8742LOC: Config.icons.use_short_names
8743DEFAULT: on
8744DOC_START
8745 If this is enabled Squid will use short URLs for icons.
8746 If disabled it will revert to the old behavior of including
8747 it's own name and port in the URL.
8748
8749 If you run a complex cache hierarchy with a mix of Squid and
8750 other proxies you may need to disable this directive.
8751DOC_END
8752
8753COMMENT_START
8754 ERROR PAGE OPTIONS
8755 -----------------------------------------------------------------------------
8756COMMENT_END
8757
8758NAME: error_directory
8759TYPE: string
8760LOC: Config.errorDirectory
43000484 8761DEFAULT: none
638402dd 8762DEFAULT_DOC: Send error pages in the clients preferred language
5473c134 8763DOC_START
8764 If you wish to create your own versions of the default
43000484
AJ
8765 error files to customize them to suit your company copy
8766 the error/template files to another directory and point
8767 this tag at them.
8768
8769 WARNING: This option will disable multi-language support
8770 on error pages if used.
5473c134 8771
8772 The squid developers are interested in making squid available in
8773 a wide variety of languages. If you are making translations for a
43000484 8774 language that Squid does not currently provide please consider
5473c134 8775 contributing your translation back to the project.
43000484
AJ
8776 http://wiki.squid-cache.org/Translations
8777
8778 The squid developers working on translations are happy to supply drop-in
8779 translated error files in exchange for any new language contributions.
8780DOC_END
8781
8782NAME: error_default_language
8783IFDEF: USE_ERR_LOCALES
8784TYPE: string
8785LOC: Config.errorDefaultLanguage
8786DEFAULT: none
638402dd 8787DEFAULT_DOC: Generate English language pages.
43000484
AJ
8788DOC_START
8789 Set the default language which squid will send error pages in
8790 if no existing translation matches the clients language
8791 preferences.
8792
8793 If unset (default) generic English will be used.
8794
8795 The squid developers are interested in making squid available in
8796 a wide variety of languages. If you are interested in making
8797 translations for any language see the squid wiki for details.
8798 http://wiki.squid-cache.org/Translations
5473c134 8799DOC_END
8800
c411820c
AJ
8801NAME: error_log_languages
8802IFDEF: USE_ERR_LOCALES
8803TYPE: onoff
8804LOC: Config.errorLogMissingLanguages
8805DEFAULT: on
8806DOC_START
8807 Log to cache.log what languages users are attempting to
8808 auto-negotiate for translations.
8809
8810 Successful negotiations are not logged. Only failures
8811 have meaning to indicate that Squid may need an upgrade
0c49f10e 8812 of its error page translations.
c411820c
AJ
8813DOC_END
8814
5b52cb6c
AJ
8815NAME: err_page_stylesheet
8816TYPE: string
8817LOC: Config.errorStylesheet
8818DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
8819DOC_START
8820 CSS Stylesheet to pattern the display of Squid default error pages.
8821
8822 For information on CSS see http://www.w3.org/Style/CSS/
8823DOC_END
8824
5473c134 8825NAME: err_html_text
8826TYPE: eol
8827LOC: Config.errHtmlText
8828DEFAULT: none
8829DOC_START
8830 HTML text to include in error messages. Make this a "mailto"
8831 URL to your admin address, or maybe just a link to your
8832 organizations Web page.
8833
8834 To include this in your error messages, you must rewrite
8835 the error template files (found in the "errors" directory).
8836 Wherever you want the 'err_html_text' line to appear,
8837 insert a %L tag in the error template file.
8838DOC_END
8839
8840NAME: email_err_data
8841COMMENT: on|off
8842TYPE: onoff
8843LOC: Config.onoff.emailErrData
8844DEFAULT: on
8845DOC_START
8846 If enabled, information about the occurred error will be
8847 included in the mailto links of the ERR pages (if %W is set)
8848 so that the email body contains the data.
8849 Syntax is <A HREF="mailto:%w%W">%w</A>
8850DOC_END
8851
8852NAME: deny_info
8853TYPE: denyinfo
8854LOC: Config.denyInfoList
8855DEFAULT: none
8856DOC_START
8857 Usage: deny_info err_page_name acl
8858 or deny_info http://... acl
43000484 8859 or deny_info TCP_RESET acl
5473c134 8860
8861 This can be used to return a ERR_ page for requests which
8862 do not pass the 'http_access' rules. Squid remembers the last
8863 acl it evaluated in http_access, and if a 'deny_info' line exists
8864 for that ACL Squid returns a corresponding error page.
8865
8866 The acl is typically the last acl on the http_access deny line which
8867 denied access. The exceptions to this rule are:
8868 - When Squid needs to request authentication credentials. It's then
8869 the first authentication related acl encountered
8870 - When none of the http_access lines matches. It's then the last
8871 acl processed on the last http_access line.
3af10ac0
AR
8872 - When the decision to deny access was made by an adaptation service,
8873 the acl name is the corresponding eCAP or ICAP service_name.
5473c134 8874
43000484
AJ
8875 NP: If providing your own custom error pages with error_directory
8876 you may also specify them by your custom file name:
8877 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
5473c134 8878
2f8abb64 8879 By default Squid will send "403 Forbidden". A different 4xx or 5xx
aed9a15b
AJ
8880 may be specified by prefixing the file name with the code and a colon.
8881 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
8882
5473c134 8883 Alternatively you can tell Squid to reset the TCP connection
8884 by specifying TCP_RESET.
15b02e9a
AJ
8885
8886 Or you can specify an error URL or URL pattern. The browsers will
aed9a15b
AJ
8887 get redirected to the specified URL after formatting tags have
8888 been replaced. Redirect will be done with 302 or 307 according to
8889 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
8890 the URL. e.g. 303:http://example.com/
15b02e9a
AJ
8891
8892 URL FORMAT TAGS:
8893 %a - username (if available. Password NOT included)
ea35939b 8894 %A - Local listening IP address the client connection was connected to
15b02e9a
AJ
8895 %B - FTP path URL
8896 %e - Error number
8897 %E - Error description
8898 %h - Squid hostname
8899 %H - Request domain name
8900 %i - Client IP Address
8901 %M - Request Method
05dbf66c 8902 %O - Unescaped message result from external ACL helper
15b02e9a
AJ
8903 %o - Message result from external ACL helper
8904 %p - Request Port number
8905 %P - Request Protocol name
8906 %R - Request URL path
8907 %T - Timestamp in RFC 1123 format
8908 %U - Full canonical URL from client
8909 (HTTPS URLs terminate with *)
8910 %u - Full canonical URL from client
8911 %w - Admin email from squid.conf
e4a8468d 8912 %x - Error name
15b02e9a
AJ
8913 %% - Literal percent (%) code
8914
5473c134 8915DOC_END
8916
8917COMMENT_START
9603207d 8918 OPTIONS INFLUENCING REQUEST FORWARDING
5473c134 8919 -----------------------------------------------------------------------------
8920COMMENT_END
8921
8922NAME: nonhierarchical_direct
e72a0ec0 8923TYPE: onoff
5473c134 8924LOC: Config.onoff.nonhierarchical_direct
e72a0ec0 8925DEFAULT: on
8926DOC_START
5473c134 8927 By default, Squid will send any non-hierarchical requests
9967aef6 8928 (not cacheable request type) direct to origin servers.
e72a0ec0 8929
638402dd 8930 When this is set to "off", Squid will prefer to send these
5473c134 8931 requests to parents.
0b0cfcf2 8932
5473c134 8933 Note that in most configurations, by turning this off you will only
8934 add latency to these request without any improvement in global hit
8935 ratio.
0b0cfcf2 8936
638402dd
AJ
8937 This option only sets a preference. If the parent is unavailable a
8938 direct connection to the origin server may still be attempted. To
8939 completely prevent direct connections use never_direct.
8d6275c0 8940DOC_END
0b0cfcf2 8941
5473c134 8942NAME: prefer_direct
8d6275c0 8943TYPE: onoff
5473c134 8944LOC: Config.onoff.prefer_direct
8d6275c0 8945DEFAULT: off
8946DOC_START
5473c134 8947 Normally Squid tries to use parents for most requests. If you for some
8948 reason like it to first try going direct and only use a parent if
8949 going direct fails set this to on.
0b0cfcf2 8950
5473c134 8951 By combining nonhierarchical_direct off and prefer_direct on you
8952 can set up Squid to use a parent as a backup path if going direct
8953 fails.
8954
8955 Note: If you want Squid to use parents for all requests see
8956 the never_direct directive. prefer_direct only modifies how Squid
8957 acts on cacheable requests.
cccac0a2 8958DOC_END
8959
96598f93
AJ
8960NAME: cache_miss_revalidate
8961COMMENT: on|off
8962TYPE: onoff
8963DEFAULT: on
8964LOC: Config.onoff.cache_miss_revalidate
8965DOC_START
2d4eefd9
AJ
8966 RFC 7232 defines a conditional request mechanism to prevent
8967 response objects being unnecessarily transferred over the network.
8968 If that mechanism is used by the client and a cache MISS occurs
8969 it can prevent new cache entries being created.
8970
8971 This option determines whether Squid on cache MISS will pass the
8972 client revalidation request to the server or tries to fetch new
8973 content for caching. It can be useful while the cache is mostly
8974 empty to more quickly have the cache populated by generating
8975 non-conditional GETs.
96598f93
AJ
8976
8977 When set to 'on' (default), Squid will pass all client If-* headers
2d4eefd9
AJ
8978 to the server. This permits server responses without a cacheable
8979 payload to be delivered and on MISS no new cache entry is created.
96598f93
AJ
8980
8981 When set to 'off' and if the request is cacheable, Squid will
8982 remove the clients If-Modified-Since and If-None-Match headers from
2d4eefd9
AJ
8983 the request sent to the server. This requests a 200 status response
8984 from the server to create a new cache entry with.
96598f93
AJ
8985DOC_END
8986
5473c134 8987NAME: always_direct
8d6275c0 8988TYPE: acl_access
5473c134 8989LOC: Config.accessList.AlwaysDirect
0b0cfcf2 8990DEFAULT: none
638402dd 8991DEFAULT_DOC: Prevent any cache_peer being used for this request.
0b0cfcf2 8992DOC_START
5473c134 8993 Usage: always_direct allow|deny [!]aclname ...
0b0cfcf2 8994
5473c134 8995 Here you can use ACL elements to specify requests which should
8996 ALWAYS be forwarded by Squid to the origin servers without using
8997 any peers. For example, to always directly forward requests for
8998 local servers ignoring any parents or siblings you may have use
8999 something like:
0b0cfcf2 9000
5473c134 9001 acl local-servers dstdomain my.domain.net
9002 always_direct allow local-servers
0b0cfcf2 9003
5473c134 9004 To always forward FTP requests directly, use
f16fbc82 9005
5473c134 9006 acl FTP proto FTP
9007 always_direct allow FTP
cccac0a2 9008
5473c134 9009 NOTE: There is a similar, but opposite option named
9010 'never_direct'. You need to be aware that "always_direct deny
9011 foo" is NOT the same thing as "never_direct allow foo". You
9012 may need to use a deny rule to exclude a more-specific case of
9013 some other rule. Example:
8d6275c0 9014
5473c134 9015 acl local-external dstdomain external.foo.net
9016 acl local-servers dstdomain .foo.net
9017 always_direct deny local-external
9018 always_direct allow local-servers
8d6275c0 9019
5473c134 9020 NOTE: If your goal is to make the client forward the request
9021 directly to the origin server bypassing Squid then this needs
9022 to be done in the client configuration. Squid configuration
9023 can only tell Squid how Squid should fetch the object.
8d6275c0 9024
5473c134 9025 NOTE: This directive is not related to caching. The replies
9026 is cached as usual even if you use always_direct. To not cache
b3567eb5 9027 the replies see the 'cache' directive.
5473c134 9028
b3567eb5
FC
9029 This clause supports both fast and slow acl types.
9030 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
cccac0a2 9031DOC_END
0976f8db 9032
5473c134 9033NAME: never_direct
9034TYPE: acl_access
9035LOC: Config.accessList.NeverDirect
9036DEFAULT: none
638402dd 9037DEFAULT_DOC: Allow DNS results to be used for this request.
8d6275c0 9038DOC_START
5473c134 9039 Usage: never_direct allow|deny [!]aclname ...
9040
9041 never_direct is the opposite of always_direct. Please read
9042 the description for always_direct if you have not already.
9043
9044 With 'never_direct' you can use ACL elements to specify
9045 requests which should NEVER be forwarded directly to origin
9046 servers. For example, to force the use of a proxy for all
9047 requests, except those in your local domain use something like:
9048
9049 acl local-servers dstdomain .foo.net
5473c134 9050 never_direct deny local-servers
9051 never_direct allow all
9052
9053 or if Squid is inside a firewall and there are local intranet
9054 servers inside the firewall use something like:
9055
9056 acl local-intranet dstdomain .foo.net
9057 acl local-external dstdomain external.foo.net
9058 always_direct deny local-external
9059 always_direct allow local-intranet
9060 never_direct allow all
9061
b3567eb5
FC
9062 This clause supports both fast and slow acl types.
9063 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
8d6275c0 9064DOC_END
0976f8db 9065
5473c134 9066COMMENT_START
9067 ADVANCED NETWORKING OPTIONS
9068 -----------------------------------------------------------------------------
9069COMMENT_END
9070
65d448bc 9071NAME: incoming_udp_average incoming_icp_average
cccac0a2 9072TYPE: int
9073DEFAULT: 6
65d448bc
AJ
9074LOC: Config.comm_incoming.udp.average
9075DOC_START
9076 Heavy voodoo here. I can't even believe you are reading this.
9077 Are you crazy? Don't even think about adjusting these unless
9078 you understand the algorithms in comm_select.c first!
9079DOC_END
cccac0a2 9080
65d448bc 9081NAME: incoming_tcp_average incoming_http_average
cccac0a2 9082TYPE: int
9083DEFAULT: 4
65d448bc
AJ
9084LOC: Config.comm_incoming.tcp.average
9085DOC_START
9086 Heavy voodoo here. I can't even believe you are reading this.
9087 Are you crazy? Don't even think about adjusting these unless
9088 you understand the algorithms in comm_select.c first!
9089DOC_END
cccac0a2 9090
9091NAME: incoming_dns_average
9092TYPE: int
9093DEFAULT: 4
65d448bc
AJ
9094LOC: Config.comm_incoming.dns.average
9095DOC_START
9096 Heavy voodoo here. I can't even believe you are reading this.
9097 Are you crazy? Don't even think about adjusting these unless
9098 you understand the algorithms in comm_select.c first!
9099DOC_END
cccac0a2 9100
65d448bc 9101NAME: min_udp_poll_cnt min_icp_poll_cnt
cccac0a2 9102TYPE: int
9103DEFAULT: 8
65d448bc
AJ
9104LOC: Config.comm_incoming.udp.min_poll
9105DOC_START
9106 Heavy voodoo here. I can't even believe you are reading this.
9107 Are you crazy? Don't even think about adjusting these unless
9108 you understand the algorithms in comm_select.c first!
9109DOC_END
cccac0a2 9110
9111NAME: min_dns_poll_cnt
9112TYPE: int
9113DEFAULT: 8
65d448bc
AJ
9114LOC: Config.comm_incoming.dns.min_poll
9115DOC_START
9116 Heavy voodoo here. I can't even believe you are reading this.
9117 Are you crazy? Don't even think about adjusting these unless
9118 you understand the algorithms in comm_select.c first!
9119DOC_END
cccac0a2 9120
65d448bc 9121NAME: min_tcp_poll_cnt min_http_poll_cnt
cccac0a2 9122TYPE: int
9123DEFAULT: 8
65d448bc 9124LOC: Config.comm_incoming.tcp.min_poll
cccac0a2 9125DOC_START
5473c134 9126 Heavy voodoo here. I can't even believe you are reading this.
9127 Are you crazy? Don't even think about adjusting these unless
9128 you understand the algorithms in comm_select.c first!
9129DOC_END
9130
9131NAME: accept_filter
5473c134 9132TYPE: string
9133DEFAULT: none
9134LOC: Config.accept_filter
9135DOC_START
0b4d4be5 9136 FreeBSD:
9137
5473c134 9138 The name of an accept(2) filter to install on Squid's
9139 listen socket(s). This feature is perhaps specific to
9140 FreeBSD and requires support in the kernel.
9141
9142 The 'httpready' filter delays delivering new connections
2324cda2 9143 to Squid until a full HTTP request has been received.
0b4d4be5 9144 See the accf_http(9) man page for details.
9145
9146 The 'dataready' filter delays delivering new connections
9147 to Squid until there is some data to process.
9148 See the accf_dataready(9) man page for details.
9149
9150 Linux:
9603207d 9151
0b4d4be5 9152 The 'data' filter delays delivering of new connections
9153 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
9154 You may optionally specify a number of seconds to wait by
9155 'data=N' where N is the number of seconds. Defaults to 30
9156 if not specified. See the tcp(7) man page for details.
5473c134 9157EXAMPLE:
0b4d4be5 9158# FreeBSD
5473c134 9159accept_filter httpready
0b4d4be5 9160# Linux
9161accept_filter data
5473c134 9162DOC_END
9163
ab2ecb0e
AJ
9164NAME: client_ip_max_connections
9165TYPE: int
9166LOC: Config.client_ip_max_connections
9167DEFAULT: -1
638402dd 9168DEFAULT_DOC: No limit.
ab2ecb0e
AJ
9169DOC_START
9170 Set an absolute limit on the number of connections a single
9171 client IP can use. Any more than this and Squid will begin to drop
9172 new connections from the client until it closes some links.
9173
6ea12e8f 9174 Note that this is a global limit. It affects all HTTP, HTCP, and FTP
ab2ecb0e
AJ
9175 connections from the client. For finer control use the ACL access controls.
9176
9177 Requires client_db to be enabled (the default).
9178
2f8abb64 9179 WARNING: This may noticeably slow down traffic received via external proxies
ab2ecb0e
AJ
9180 or NAT devices and cause them to rebound error messages back to their clients.
9181DOC_END
9182
5473c134 9183NAME: tcp_recv_bufsize
9184COMMENT: (bytes)
9185TYPE: b_size_t
9186DEFAULT: 0 bytes
638402dd 9187DEFAULT_DOC: Use operating system TCP defaults.
5473c134 9188LOC: Config.tcpRcvBufsz
9189DOC_START
9190 Size of receive buffer to set for TCP sockets. Probably just
638402dd
AJ
9191 as easy to change your kernel's default.
9192 Omit from squid.conf to use the default buffer size.
5473c134 9193DOC_END
9194
9195COMMENT_START
9196 ICAP OPTIONS
9197 -----------------------------------------------------------------------------
9198COMMENT_END
9199
9200NAME: icap_enable
9201TYPE: onoff
9202IFDEF: ICAP_CLIENT
9203COMMENT: on|off
26cc52cb 9204LOC: Adaptation::Icap::TheConfig.onoff
5473c134 9205DEFAULT: off
9206DOC_START
53e738c6 9207 If you want to enable the ICAP module support, set this to on.
5473c134 9208DOC_END
9209
9210NAME: icap_connect_timeout
9211TYPE: time_t
9212DEFAULT: none
26cc52cb 9213LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
5473c134 9214IFDEF: ICAP_CLIENT
9215DOC_START
9216 This parameter specifies how long to wait for the TCP connect to
9217 the requested ICAP server to complete before giving up and either
9218 terminating the HTTP transaction or bypassing the failure.
9219
9220 The default for optional services is peer_connect_timeout.
9221 The default for essential services is connect_timeout.
9222 If this option is explicitly set, its value applies to all services.
9223DOC_END
9224
9225NAME: icap_io_timeout
9226COMMENT: time-units
9227TYPE: time_t
9228DEFAULT: none
638402dd 9229DEFAULT_DOC: Use read_timeout.
26cc52cb 9230LOC: Adaptation::Icap::TheConfig.io_timeout_raw
5473c134 9231IFDEF: ICAP_CLIENT
9232DOC_START
9233 This parameter specifies how long to wait for an I/O activity on
9234 an established, active ICAP connection before giving up and
9235 either terminating the HTTP transaction or bypassing the
9236 failure.
5473c134 9237DOC_END
9238
9239NAME: icap_service_failure_limit
8277060a
CT
9240COMMENT: limit [in memory-depth time-units]
9241TYPE: icap_service_failure_limit
5473c134 9242IFDEF: ICAP_CLIENT
8277060a 9243LOC: Adaptation::Icap::TheConfig
5473c134 9244DEFAULT: 10
9245DOC_START
9246 The limit specifies the number of failures that Squid tolerates
9247 when establishing a new TCP connection with an ICAP service. If
9248 the number of failures exceeds the limit, the ICAP service is
9249 not used for new ICAP requests until it is time to refresh its
8277060a 9250 OPTIONS.
5473c134 9251
9252 A negative value disables the limit. Without the limit, an ICAP
9253 service will not be considered down due to connectivity failures
9254 between ICAP OPTIONS requests.
8277060a
CT
9255
9256 Squid forgets ICAP service failures older than the specified
9603207d 9257 value of memory-depth. The memory fading algorithm
9258 is approximate because Squid does not remember individual
8277060a
CT
9259 errors but groups them instead, splitting the option
9260 value into ten time slots of equal length.
9261
9603207d 9262 When memory-depth is 0 and by default this option has no
8277060a
CT
9263 effect on service failure expiration.
9264
9265 Squid always forgets failures when updating service settings
9266 using an ICAP OPTIONS transaction, regardless of this option
9267 setting.
9268
9269 For example,
9270 # suspend service usage after 10 failures in 5 seconds:
9271 icap_service_failure_limit 10 in 5 seconds
cccac0a2 9272DOC_END
9273
5473c134 9274NAME: icap_service_revival_delay
cccac0a2 9275TYPE: int
5473c134 9276IFDEF: ICAP_CLIENT
26cc52cb 9277LOC: Adaptation::Icap::TheConfig.service_revival_delay
5473c134 9278DEFAULT: 180
cccac0a2 9279DOC_START
5473c134 9280 The delay specifies the number of seconds to wait after an ICAP
9281 OPTIONS request failure before requesting the options again. The
9282 failed ICAP service is considered "down" until fresh OPTIONS are
9283 fetched.
cccac0a2 9284
5473c134 9285 The actual delay cannot be smaller than the hardcoded minimum
9286 delay of 30 seconds.
cccac0a2 9287DOC_END
9288
5473c134 9289NAME: icap_preview_enable
cccac0a2 9290TYPE: onoff
5473c134 9291IFDEF: ICAP_CLIENT
9292COMMENT: on|off
26cc52cb 9293LOC: Adaptation::Icap::TheConfig.preview_enable
ac7a62f9 9294DEFAULT: on
cccac0a2 9295DOC_START
ac7a62f9 9296 The ICAP Preview feature allows the ICAP server to handle the
9297 HTTP message by looking only at the beginning of the message body
9603207d 9298 or even without receiving the body at all. In some environments,
ac7a62f9 9299 previews greatly speedup ICAP processing.
9300
9301 During an ICAP OPTIONS transaction, the server may tell Squid what
9302 HTTP messages should be previewed and how big the preview should be.
9303 Squid will not use Preview if the server did not request one.
9304
9305 To disable ICAP Preview for all ICAP services, regardless of
9306 individual ICAP server OPTIONS responses, set this option to "off".
9307Example:
9308icap_preview_enable off
cccac0a2 9309DOC_END
9310
5473c134 9311NAME: icap_preview_size
9312TYPE: int
9313IFDEF: ICAP_CLIENT
26cc52cb 9314LOC: Adaptation::Icap::TheConfig.preview_size
5473c134 9315DEFAULT: -1
638402dd 9316DEFAULT_DOC: No preview sent.
cccac0a2 9317DOC_START
53e738c6 9318 The default size of preview data to be sent to the ICAP server.
638402dd 9319 This value might be overwritten on a per server basis by OPTIONS requests.
cccac0a2 9320DOC_END
9321
83c51da9
CT
9322NAME: icap_206_enable
9323TYPE: onoff
9324IFDEF: ICAP_CLIENT
9325COMMENT: on|off
9326LOC: Adaptation::Icap::TheConfig.allow206_enable
9327DEFAULT: on
9328DOC_START
9329 206 (Partial Content) responses is an ICAP extension that allows the
9330 ICAP agents to optionally combine adapted and original HTTP message
9331 content. The decision to combine is postponed until the end of the
9332 ICAP response. Squid supports Partial Content extension by default.
9333
9334 Activation of the Partial Content extension is negotiated with each
9335 ICAP service during OPTIONS exchange. Most ICAP servers should handle
2f8abb64 9336 negotiation correctly even if they do not support the extension, but
83c51da9
CT
9337 some might fail. To disable Partial Content support for all ICAP
9338 services and to avoid any negotiation, set this option to "off".
9339
9340 Example:
9341 icap_206_enable off
9342DOC_END
9343
5473c134 9344NAME: icap_default_options_ttl
9345TYPE: int
9346IFDEF: ICAP_CLIENT
26cc52cb 9347LOC: Adaptation::Icap::TheConfig.default_options_ttl
5473c134 9348DEFAULT: 60
cccac0a2 9349DOC_START
53e738c6 9350 The default TTL value for ICAP OPTIONS responses that don't have
5473c134 9351 an Options-TTL header.
cccac0a2 9352DOC_END
9353
5473c134 9354NAME: icap_persistent_connections
9355TYPE: onoff
9356IFDEF: ICAP_CLIENT
9357COMMENT: on|off
26cc52cb 9358LOC: Adaptation::Icap::TheConfig.reuse_connections
5473c134 9359DEFAULT: on
cccac0a2 9360DOC_START
5473c134 9361 Whether or not Squid should use persistent connections to
9362 an ICAP server.
cccac0a2 9363DOC_END
9364
22fff3bf 9365NAME: adaptation_send_client_ip icap_send_client_ip
5473c134 9366TYPE: onoff
22fff3bf 9367IFDEF: USE_ADAPTATION
5473c134 9368COMMENT: on|off
22fff3bf 9369LOC: Adaptation::Config::send_client_ip
5473c134 9370DEFAULT: off
cccac0a2 9371DOC_START
ea3ae478
AR
9372 If enabled, Squid shares HTTP client IP information with adaptation
9373 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
9374 For eCAP, Squid sets the libecap::metaClientIp transaction option.
9375
9376 See also: adaptation_uses_indirect_client
cccac0a2 9377DOC_END
9378
22fff3bf 9379NAME: adaptation_send_username icap_send_client_username
5473c134 9380TYPE: onoff
22fff3bf 9381IFDEF: USE_ADAPTATION
5473c134 9382COMMENT: on|off
22fff3bf 9383LOC: Adaptation::Config::send_username
5473c134 9384DEFAULT: off
cccac0a2 9385DOC_START
5473c134 9386 This sends authenticated HTTP client username (if available) to
22fff3bf
AR
9387 the adaptation service.
9388
9389 For ICAP, the username value is encoded based on the
5473c134 9390 icap_client_username_encode option and is sent using the header
9391 specified by the icap_client_username_header option.
cccac0a2 9392DOC_END
9393
5473c134 9394NAME: icap_client_username_header
cccac0a2 9395TYPE: string
5473c134 9396IFDEF: ICAP_CLIENT
26cc52cb 9397LOC: Adaptation::Icap::TheConfig.client_username_header
5473c134 9398DEFAULT: X-Client-Username
cccac0a2 9399DOC_START
db49f682 9400 ICAP request header name to use for adaptation_send_username.
cccac0a2 9401DOC_END
9402
5473c134 9403NAME: icap_client_username_encode
cccac0a2 9404TYPE: onoff
5473c134 9405IFDEF: ICAP_CLIENT
9406COMMENT: on|off
26cc52cb 9407LOC: Adaptation::Icap::TheConfig.client_username_encode
5473c134 9408DEFAULT: off
cccac0a2 9409DOC_START
5473c134 9410 Whether to base64 encode the authenticated client username.
cccac0a2 9411DOC_END
9412
5473c134 9413NAME: icap_service
9414TYPE: icap_service_type
9415IFDEF: ICAP_CLIENT
26cc52cb 9416LOC: Adaptation::Icap::TheConfig
5473c134 9417DEFAULT: none
cccac0a2 9418DOC_START
a22e6cd3 9419 Defines a single ICAP service using the following format:
cccac0a2 9420
c25c2836 9421 icap_service id vectoring_point uri [option ...]
7d90757b 9422
c25c2836
CT
9423 id: ID
9424 an opaque identifier or name which is used to direct traffic to
9425 this specific service. Must be unique among all adaptation
9426 services in squid.conf.
a22e6cd3
AR
9427
9428 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
f3db09e2 9429 This specifies at which point of transaction processing the
9430 ICAP service should be activated. *_postcache vectoring points
9431 are not yet supported.
a22e6cd3 9432
c25c2836 9433 uri: icap://servername:port/servicepath
a22e6cd3 9434 ICAP server and service location.
1b091aec
CT
9435 icaps://servername:port/servicepath
9436 The "icap:" URI scheme is used for traditional ICAP server and
9437 service location (default port is 1344, connections are not
9438 encrypted). The "icaps:" URI scheme is for Secure ICAP
9439 services that use SSL/TLS-encrypted ICAP connections (by
9440 default, on port 11344).
a22e6cd3
AR
9441
9442 ICAP does not allow a single service to handle both REQMOD and RESPMOD
9443 transactions. Squid does not enforce that requirement. You can specify
9444 services with the same service_url and different vectoring_points. You
9445 can even specify multiple identical services as long as their
9446 service_names differ.
9447
3caa16d2
AR
9448 To activate a service, use the adaptation_access directive. To group
9449 services, use adaptation_service_chain and adaptation_service_set.
a22e6cd3
AR
9450
9451 Service options are separated by white space. ICAP services support
9452 the following name=value options:
9453
9454 bypass=on|off|1|0
9455 If set to 'on' or '1', the ICAP service is treated as
9456 optional. If the service cannot be reached or malfunctions,
9457 Squid will try to ignore any errors and process the message as
9458 if the service was not enabled. No all ICAP errors can be
9459 bypassed. If set to 0, the ICAP service is treated as
9460 essential and all ICAP errors will result in an error page
9461 returned to the HTTP client.
9462
9463 Bypass is off by default: services are treated as essential.
9464
9465 routing=on|off|1|0
9466 If set to 'on' or '1', the ICAP service is allowed to
9467 dynamically change the current message adaptation plan by
9468 returning a chain of services to be used next. The services
9469 are specified using the X-Next-Services ICAP response header
9470 value, formatted as a comma-separated list of service names.
e2851fe7
AR
9471 Each named service should be configured in squid.conf. Other
9472 services are ignored. An empty X-Next-Services value results
9473 in an empty plan which ends the current adaptation.
9474
9475 Dynamic adaptation plan may cross or cover multiple supported
9476 vectoring points in their natural processing order.
a22e6cd3
AR
9477
9478 Routing is not allowed by default: the ICAP X-Next-Services
9479 response header is ignored.
9480
e6713f4e
AJ
9481 ipv6=on|off
9482 Only has effect on split-stack systems. The default on those systems
9483 is to use IPv4-only connections. When set to 'on' this option will
9484 make Squid use IPv6-only connections to contact this ICAP service.
9485
2dba5b8e
CT
9486 on-overload=block|bypass|wait|force
9487 If the service Max-Connections limit has been reached, do
9488 one of the following for each new ICAP transaction:
9489 * block: send an HTTP error response to the client
9490 * bypass: ignore the "over-connected" ICAP service
9491 * wait: wait (in a FIFO queue) for an ICAP connection slot
9603207d 9492 * force: proceed, ignoring the Max-Connections limit
2dba5b8e
CT
9493
9494 In SMP mode with N workers, each worker assumes the service
9495 connection limit is Max-Connections/N, even though not all
9496 workers may use a given service.
9497
9498 The default value is "bypass" if service is bypassable,
9499 otherwise it is set to "wait".
9603207d 9500
2dba5b8e
CT
9501
9502 max-conn=number
9503 Use the given number as the Max-Connections limit, regardless
9504 of the Max-Connections value given by the service, if any.
9505
88df846b
CT
9506 connection-encryption=on|off
9507 Determines the ICAP service effect on the connections_encrypted
9508 ACL.
9509
9510 The default is "on" for Secure ICAP services (i.e., those
9511 with the icaps:// service URIs scheme) and "off" for plain ICAP
9512 services.
9513
9514 Does not affect ICAP connections (e.g., does not turn Secure
9515 ICAP on or off).
9516
4dd2c9d6 9517 ==== ICAPS / TLS OPTIONS ====
1b091aec
CT
9518
9519 These options are used for Secure ICAP (icaps://....) services only.
9520
4dd2c9d6 9521 tls-cert=/path/to/ssl/certificate
51e09c08
AJ
9522 A client X.509 certificate to use when connecting to
9523 this ICAP server.
1b091aec 9524
4dd2c9d6 9525 tls-key=/path/to/ssl/key
51e09c08
AJ
9526 The private key corresponding to the previous
9527 tls-cert= option.
9528
9529 If tls-key= is not specified tls-cert= is assumed to
9530 reference a PEM file containing both the certificate
9531 and private key.
1b091aec 9532
4dd2c9d6 9533 tls-cipher=... The list of valid TLS/SSL ciphers to use when connecting
1b091aec
CT
9534 to this icap server.
9535
1cc44095
AJ
9536 tls-min-version=1.N
9537 The minimum TLS protocol version to permit. To control
3f5b28fe 9538 SSLv3 use the tls-options= parameter.
1cc44095
AJ
9539 Supported Values: 1.0 (default), 1.1, 1.2
9540
4dd2c9d6 9541 tls-options=... Specify various OpenSSL library options:
1b091aec
CT
9542
9543 NO_SSLv3 Disallow the use of SSLv3
4dd2c9d6 9544
1b091aec
CT
9545 SINGLE_DH_USE
9546 Always create a new key when using
9547 temporary/ephemeral DH key exchanges
4dd2c9d6 9548
1b091aec 9549 ALL Enable various bug workarounds
4dd2c9d6
AJ
9550 suggested as "harmless" by OpenSSL
9551 Be warned that this reduces SSL/TLS
9552 strength to some attacks.
1b091aec
CT
9553
9554 See the OpenSSL SSL_CTX_set_options documentation for a
4dd2c9d6
AJ
9555 more complete list. Options relevant only to SSLv2 are
9556 not supported.
1b091aec 9557
86a84cc0
AJ
9558 tls-cafile= PEM file containing CA certificates to use when verifying
9559 the icap server certificate.
9560 Use to specify intermediate CA certificate(s) if not sent
9561 by the server. Or the full CA chain for the server when
435c72b0 9562 using the tls-default-ca=off flag.
86a84cc0 9563 May be repeated to load multiple files.
1b091aec 9564
4dd2c9d6 9565 tls-capath=... A directory containing additional CA certificates to
1b091aec 9566 use when verifying the icap server certificate.
86a84cc0 9567 Requires OpenSSL or LibreSSL.
1b091aec 9568
4dd2c9d6 9569 tls-crlfile=... A certificate revocation list file to use when
1b091aec
CT
9570 verifying the icap server certificate.
9571
4dd2c9d6 9572 tls-flags=... Specify various flags modifying the Squid TLS implementation:
1b091aec
CT
9573
9574 DONT_VERIFY_PEER
9575 Accept certificates even if they fail to
9576 verify.
1b091aec
CT
9577 DONT_VERIFY_DOMAIN
9578 Don't verify the icap server certificate
9579 matches the server name
9580
435c72b0
AJ
9581 tls-default-ca[=off]
9582 Whether to use the system Trusted CAs. Default is ON.
8b253b83 9583
4dd2c9d6 9584 tls-domain= The icap server name as advertised in it's certificate.
1b091aec
CT
9585 Used for verifying the correctness of the received icap
9586 server certificate. If not specified the icap server
9587 hostname extracted from ICAP URI will be used.
9588
a22e6cd3
AR
9589 Older icap_service format without optional named parameters is
9590 deprecated but supported for backward compatibility.
5473c134 9591
5473c134 9592Example:
c25c2836 9593icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
1b091aec 9594icap_service svcLogger reqmod_precache icaps://icap2.mydomain.net:11344/reqmod routing=on
cccac0a2 9595DOC_END
9596
5473c134 9597NAME: icap_class
9598TYPE: icap_class_type
9599IFDEF: ICAP_CLIENT
21a26d31 9600LOC: none
5473c134 9601DEFAULT: none
cccac0a2 9602DOC_START
a22e6cd3 9603 This deprecated option was documented to define an ICAP service
62c7f90e 9604 chain, even though it actually defined a set of similar, redundant
9603207d 9605 services, and the chains were not supported.
5473c134 9606
62c7f90e 9607 To define a set of redundant services, please use the
a22e6cd3
AR
9608 adaptation_service_set directive. For service chains, use
9609 adaptation_service_chain.
cccac0a2 9610DOC_END
9611
5473c134 9612NAME: icap_access
9613TYPE: icap_access_type
9614IFDEF: ICAP_CLIENT
21a26d31 9615LOC: none
cccac0a2 9616DEFAULT: none
cccac0a2 9617DOC_START
a22e6cd3 9618 This option is deprecated. Please use adaptation_access, which
62c7f90e
AR
9619 has the same ICAP functionality, but comes with better
9620 documentation, and eCAP support.
cccac0a2 9621DOC_END
9622
57afc994
AR
9623COMMENT_START
9624 eCAP OPTIONS
9625 -----------------------------------------------------------------------------
9626COMMENT_END
9627
21a26d31
AR
9628NAME: ecap_enable
9629TYPE: onoff
9630IFDEF: USE_ECAP
9631COMMENT: on|off
574b508c 9632LOC: Adaptation::Ecap::TheConfig.onoff
21a26d31
AR
9633DEFAULT: off
9634DOC_START
9635 Controls whether eCAP support is enabled.
9636DOC_END
9637
9638NAME: ecap_service
9639TYPE: ecap_service_type
9640IFDEF: USE_ECAP
574b508c 9641LOC: Adaptation::Ecap::TheConfig
21a26d31
AR
9642DEFAULT: none
9643DOC_START
9644 Defines a single eCAP service
9645
c25c2836 9646 ecap_service id vectoring_point uri [option ...]
21a26d31 9647
c25c2836
CT
9648 id: ID
9649 an opaque identifier or name which is used to direct traffic to
9650 this specific service. Must be unique among all adaptation
9651 services in squid.conf.
9652
9653 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
21a26d31
AR
9654 This specifies at which point of transaction processing the
9655 eCAP service should be activated. *_postcache vectoring points
9656 are not yet supported.
c25c2836
CT
9657
9658 uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
9659 Squid uses the eCAP service URI to match this configuration
9660 line with one of the dynamically loaded services. Each loaded
9661 eCAP service must have a unique URI. Obtain the right URI from
9662 the service provider.
9663
3caa16d2
AR
9664 To activate a service, use the adaptation_access directive. To group
9665 services, use adaptation_service_chain and adaptation_service_set.
c25c2836
CT
9666
9667 Service options are separated by white space. eCAP services support
9668 the following name=value options:
9669
9670 bypass=on|off|1|0
9671 If set to 'on' or '1', the eCAP service is treated as optional.
9672 If the service cannot be reached or malfunctions, Squid will try
9673 to ignore any errors and process the message as if the service
21a26d31 9674 was not enabled. No all eCAP errors can be bypassed.
c25c2836
CT
9675 If set to 'off' or '0', the eCAP service is treated as essential
9676 and all eCAP errors will result in an error page returned to the
21a26d31 9677 HTTP client.
c25c2836
CT
9678
9679 Bypass is off by default: services are treated as essential.
9680
9681 routing=on|off|1|0
9682 If set to 'on' or '1', the eCAP service is allowed to
9683 dynamically change the current message adaptation plan by
9684 returning a chain of services to be used next.
9685
9686 Dynamic adaptation plan may cross or cover multiple supported
9687 vectoring points in their natural processing order.
9688
9689 Routing is not allowed by default.
9690
88df846b
CT
9691 connection-encryption=on|off
9692 Determines the eCAP service effect on the connections_encrypted
9603207d 9693 ACL.
88df846b
CT
9694
9695 Defaults to "on", which does not taint the master transaction
9696 w.r.t. that ACL.
9697
9698 Does not affect eCAP API calls.
9699
c25c2836
CT
9700 Older ecap_service format without optional named parameters is
9701 deprecated but supported for backward compatibility.
9702
21a26d31
AR
9703
9704Example:
c25c2836
CT
9705ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
9706ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
21a26d31
AR
9707DOC_END
9708
57afc994
AR
9709NAME: loadable_modules
9710TYPE: wordlist
9711IFDEF: USE_LOADABLE_MODULES
9712LOC: Config.loadable_module_names
9713DEFAULT: none
9714DOC_START
9715 Instructs Squid to load the specified dynamic module(s) or activate
9716 preloaded module(s).
9717Example:
9718loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
9719DOC_END
9720
62c7f90e
AR
9721COMMENT_START
9722 MESSAGE ADAPTATION OPTIONS
9723 -----------------------------------------------------------------------------
9724COMMENT_END
9725
9726NAME: adaptation_service_set
9727TYPE: adaptation_service_set_type
9728IFDEF: USE_ADAPTATION
9729LOC: none
9730DEFAULT: none
9731DOC_START
9732
a22e6cd3
AR
9733 Configures an ordered set of similar, redundant services. This is
9734 useful when hot standby or backup adaptation servers are available.
9735
9736 adaptation_service_set set_name service_name1 service_name2 ...
9737
9738 The named services are used in the set declaration order. The first
9739 applicable adaptation service from the set is used first. The next
9740 applicable service is tried if and only if the transaction with the
9741 previous service fails and the message waiting to be adapted is still
9742 intact.
62c7f90e 9743
a22e6cd3
AR
9744 When adaptation starts, broken services are ignored as if they were
9745 not a part of the set. A broken service is a down optional service.
62c7f90e 9746
a22e6cd3
AR
9747 The services in a set must be attached to the same vectoring point
9748 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
9749
9750 If all services in a set are optional then adaptation failures are
9751 bypassable. If all services in the set are essential, then a
9752 transaction failure with one service may still be retried using
9753 another service from the set, but when all services fail, the master
9754 transaction fails as well.
9755
9756 A set may contain a mix of optional and essential services, but that
9757 is likely to lead to surprising results because broken services become
9758 ignored (see above), making previously bypassable failures fatal.
9759 Technically, it is the bypassability of the last failed service that
9760 matters.
9761
9762 See also: adaptation_access adaptation_service_chain
62c7f90e
AR
9763
9764Example:
9765adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
9766adaptation service_set svcLogger loggerLocal loggerRemote
9767DOC_END
9768
a22e6cd3
AR
9769NAME: adaptation_service_chain
9770TYPE: adaptation_service_chain_type
9771IFDEF: USE_ADAPTATION
9772LOC: none
9773DEFAULT: none
9774DOC_START
9775
9776 Configures a list of complementary services that will be applied
9777 one-by-one, forming an adaptation chain or pipeline. This is useful
9778 when Squid must perform different adaptations on the same message.
9779
9780 adaptation_service_chain chain_name service_name1 svc_name2 ...
9781
9782 The named services are used in the chain declaration order. The first
9783 applicable adaptation service from the chain is used first. The next
9784 applicable service is applied to the successful adaptation results of
9785 the previous service in the chain.
9786
9787 When adaptation starts, broken services are ignored as if they were
9788 not a part of the chain. A broken service is a down optional service.
9789
9790 Request satisfaction terminates the adaptation chain because Squid
9791 does not currently allow declaration of RESPMOD services at the
9792 "reqmod_precache" vectoring point (see icap_service or ecap_service).
9793
9794 The services in a chain must be attached to the same vectoring point
9795 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
9796
9797 A chain may contain a mix of optional and essential services. If an
9798 essential adaptation fails (or the failure cannot be bypassed for
9799 other reasons), the master transaction fails. Otherwise, the failure
9800 is bypassed as if the failed adaptation service was not in the chain.
9801
9802 See also: adaptation_access adaptation_service_set
9803
9804Example:
9805adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
9806DOC_END
9807
62c7f90e
AR
9808NAME: adaptation_access
9809TYPE: adaptation_access_type
9810IFDEF: USE_ADAPTATION
9811LOC: none
9812DEFAULT: none
638402dd 9813DEFAULT_DOC: Allow, unless rules exist in squid.conf.
62c7f90e
AR
9814DOC_START
9815 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
9816
9817 adaptation_access service_name allow|deny [!]aclname...
9818 adaptation_access set_name allow|deny [!]aclname...
9819
9820 At each supported vectoring point, the adaptation_access
9821 statements are processed in the order they appear in this
9822 configuration file. Statements pointing to the following services
9823 are ignored (i.e., skipped without checking their ACL):
9824
9825 - services serving different vectoring points
9826 - "broken-but-bypassable" services
9827 - "up" services configured to ignore such transactions
9828 (e.g., based on the ICAP Transfer-Ignore header).
9829
9830 When a set_name is used, all services in the set are checked
9831 using the same rules, to find the first applicable one. See
9832 adaptation_service_set for details.
9833
9834 If an access list is checked and there is a match, the
9835 processing stops: For an "allow" rule, the corresponding
9836 adaptation service is used for the transaction. For a "deny"
9837 rule, no adaptation service is activated.
9838
9839 It is currently not possible to apply more than one adaptation
9840 service at the same vectoring point to the same HTTP transaction.
9841
9842 See also: icap_service and ecap_service
9843
9844Example:
9845adaptation_access service_1 allow all
9846DOC_END
9847
a22e6cd3
AR
9848NAME: adaptation_service_iteration_limit
9849TYPE: int
9850IFDEF: USE_ADAPTATION
9851LOC: Adaptation::Config::service_iteration_limit
9852DEFAULT: 16
9853DOC_START
9854 Limits the number of iterations allowed when applying adaptation
9855 services to a message. If your longest adaptation set or chain
9856 may have more than 16 services, increase the limit beyond its
9857 default value of 16. If detecting infinite iteration loops sooner
9858 is critical, make the iteration limit match the actual number
9859 of services in your longest adaptation set or chain.
9860
9861 Infinite adaptation loops are most likely with routing services.
9862
9863 See also: icap_service routing=1
9864DOC_END
9865
3ff65596
AR
9866NAME: adaptation_masterx_shared_names
9867TYPE: string
9868IFDEF: USE_ADAPTATION
9869LOC: Adaptation::Config::masterx_shared_name
9870DEFAULT: none
9871DOC_START
9872 For each master transaction (i.e., the HTTP request and response
9873 sequence, including all related ICAP and eCAP exchanges), Squid
9874 maintains a table of metadata. The table entries are (name, value)
9875 pairs shared among eCAP and ICAP exchanges. The table is destroyed
9876 with the master transaction.
9877
9878 This option specifies the table entry names that Squid must accept
9879 from and forward to the adaptation transactions.
9880
9603207d 9881 An ICAP REQMOD or RESPMOD transaction may set an entry in the
9882 shared table by returning an ICAP header field with a name
6666da11
AR
9883 specified in adaptation_masterx_shared_names.
9884
9885 An eCAP REQMOD or RESPMOD transaction may set an entry in the
9886 shared table by implementing the libecap::visitEachOption() API
9887 to provide an option with a name specified in
9888 adaptation_masterx_shared_names.
5038f9d8
AR
9889
9890 Squid will store and forward the set entry to subsequent adaptation
3ff65596
AR
9891 transactions within the same master transaction scope.
9892
9893 Only one shared entry name is supported at this time.
9894
9895Example:
9896# share authentication information among ICAP services
9897adaptation_masterx_shared_names X-Subscriber-ID
9898DOC_END
9899
71be37e0 9900NAME: adaptation_meta
d7f4a0b7 9901TYPE: note
71be37e0
CT
9902IFDEF: USE_ADAPTATION
9903LOC: Adaptation::Config::metaHeaders
9904DEFAULT: none
9905DOC_START
9906 This option allows Squid administrator to add custom ICAP request
9907 headers or eCAP options to Squid ICAP requests or eCAP transactions.
9908 Use it to pass custom authentication tokens and other
9909 transaction-state related meta information to an ICAP/eCAP service.
9603207d 9910
71be37e0
CT
9911 The addition of a meta header is ACL-driven:
9912 adaptation_meta name value [!]aclname ...
9603207d 9913
71be37e0
CT
9914 Processing for a given header name stops after the first ACL list match.
9915 Thus, it is impossible to add two headers with the same name. If no ACL
9603207d 9916 lists match for a given header name, no such header is added. For
71be37e0 9917 example:
9603207d 9918
71be37e0
CT
9919 # do not debug transactions except for those that need debugging
9920 adaptation_meta X-Debug 1 needs_debugging
9603207d 9921
71be37e0
CT
9922 # log all transactions except for those that must remain secret
9923 adaptation_meta X-Log 1 !keep_secret
9603207d 9924
71be37e0
CT
9925 # mark transactions from users in the "G 1" group
9926 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
9603207d 9927
71be37e0
CT
9928 The "value" parameter may be a regular squid.conf token or a "double
9929 quoted string". Within the quoted string, use backslash (\) to escape
9930 any character, which is currently only useful for escaping backslashes
9931 and double quotes. For example,
9932 "this string has one backslash (\\) and two \"quotes\""
d7f4a0b7
CT
9933
9934 Used adaptation_meta header values may be logged via %note
9935 logformat code. If multiple adaptation_meta headers with the same name
9936 are used during master transaction lifetime, the header values are
9937 logged in the order they were used and duplicate values are ignored
9938 (only the first repeated value will be logged).
71be37e0
CT
9939DOC_END
9940
3ff65596
AR
9941NAME: icap_retry
9942TYPE: acl_access
9943IFDEF: ICAP_CLIENT
9944LOC: Adaptation::Icap::TheConfig.repeat
3ff65596
AR
9945DEFAULT_IF_NONE: deny all
9946DOC_START
9947 This ACL determines which retriable ICAP transactions are
9948 retried. Transactions that received a complete ICAP response
9949 and did not have to consume or produce HTTP bodies to receive
9950 that response are usually retriable.
9951
9952 icap_retry allow|deny [!]aclname ...
9953
9954 Squid automatically retries some ICAP I/O timeouts and errors
9955 due to persistent connection race conditions.
9956
9957 See also: icap_retry_limit
9958DOC_END
9959
9960NAME: icap_retry_limit
9961TYPE: int
9962IFDEF: ICAP_CLIENT
9963LOC: Adaptation::Icap::TheConfig.repeat_limit
9964DEFAULT: 0
638402dd 9965DEFAULT_DOC: No retries are allowed.
3ff65596 9966DOC_START
638402dd 9967 Limits the number of retries allowed.
3ff65596
AR
9968
9969 Communication errors due to persistent connection race
9970 conditions are unavoidable, automatically retried, and do not
9971 count against this limit.
9972
9973 See also: icap_retry
9974DOC_END
9975
9976
5473c134 9977COMMENT_START
9978 DNS OPTIONS
9979 -----------------------------------------------------------------------------
9980COMMENT_END
9981
9982NAME: check_hostnames
cccac0a2 9983TYPE: onoff
cccac0a2 9984DEFAULT: off
5473c134 9985LOC: Config.onoff.check_hostnames
cccac0a2 9986DOC_START
5473c134 9987 For security and stability reasons Squid can check
9988 hostnames for Internet standard RFC compliance. If you want
9989 Squid to perform these checks turn this directive on.
cccac0a2 9990DOC_END
9991
5473c134 9992NAME: allow_underscore
cccac0a2 9993TYPE: onoff
cccac0a2 9994DEFAULT: on
5473c134 9995LOC: Config.onoff.allow_underscore
cccac0a2 9996DOC_START
5473c134 9997 Underscore characters is not strictly allowed in Internet hostnames
9998 but nevertheless used by many sites. Set this to off if you want
9999 Squid to be strict about the standard.
10000 This check is performed only when check_hostnames is set to on.
cccac0a2 10001DOC_END
10002
5473c134 10003NAME: dns_retransmit_interval
fd0f51c4 10004TYPE: time_msec
5473c134 10005DEFAULT: 5 seconds
10006LOC: Config.Timeout.idns_retransmit
cccac0a2 10007DOC_START
5473c134 10008 Initial retransmit interval for DNS queries. The interval is
10009 doubled each time all configured DNS servers have been tried.
cccac0a2 10010DOC_END
10011
5473c134 10012NAME: dns_timeout
fd0f51c4 10013TYPE: time_msec
a541c34e 10014DEFAULT: 30 seconds
5473c134 10015LOC: Config.Timeout.idns_query
cccac0a2 10016DOC_START
5473c134 10017 DNS Query timeout. If no response is received to a DNS query
10018 within this time all DNS servers for the queried domain
10019 are assumed to be unavailable.
cccac0a2 10020DOC_END
10021
e210930b
AJ
10022NAME: dns_packet_max
10023TYPE: b_ssize_t
638402dd 10024DEFAULT_DOC: EDNS disabled
e210930b
AJ
10025DEFAULT: none
10026LOC: Config.dns.packet_max
e210930b
AJ
10027DOC_START
10028 Maximum number of bytes packet size to advertise via EDNS.
10029 Set to "none" to disable EDNS large packet support.
9603207d 10030
e210930b
AJ
10031 For legacy reasons DNS UDP replies will default to 512 bytes which
10032 is too small for many responses. EDNS provides a means for Squid to
10033 negotiate receiving larger responses back immediately without having
10034 to failover with repeat requests. Responses larger than this limit
10035 will retain the old behaviour of failover to TCP DNS.
9603207d 10036
e210930b
AJ
10037 Squid has no real fixed limit internally, but allowing packet sizes
10038 over 1500 bytes requires network jumbogram support and is usually not
10039 necessary.
9603207d 10040
e210930b
AJ
10041 WARNING: The RFC also indicates that some older resolvers will reply
10042 with failure of the whole request if the extension is added. Some
10043 resolvers have already been identified which will reply with mangled
10044 EDNS response on occasion. Usually in response to many-KB jumbogram
10045 sizes being advertised by Squid.
10046 Squid will currently treat these both as an unable-to-resolve domain
10047 even if it would be resolvable without EDNS.
10048DOC_END
10049
5473c134 10050NAME: dns_defnames
10051COMMENT: on|off
cccac0a2 10052TYPE: onoff
cccac0a2 10053DEFAULT: off
638402dd 10054DEFAULT_DOC: Search for single-label domain names is disabled.
5473c134 10055LOC: Config.onoff.res_defnames
cccac0a2 10056DOC_START
5473c134 10057 Normally the RES_DEFNAMES resolver option is disabled
10058 (see res_init(3)). This prevents caches in a hierarchy
10059 from interpreting single-component hostnames locally. To allow
10060 Squid to handle single-component names, enable this option.
cccac0a2 10061DOC_END
10062
bce61b00
AJ
10063NAME: dns_multicast_local
10064COMMENT: on|off
10065TYPE: onoff
10066DEFAULT: off
10067DEFAULT_DOC: Search for .local and .arpa names is disabled.
10068LOC: Config.onoff.dns_mdns
10069DOC_START
10070 When set to on, Squid sends multicast DNS lookups on the local
10071 network for domains ending in .local and .arpa.
10072 This enables local servers and devices to be contacted in an
10073 ad-hoc or zero-configuration network environment.
10074DOC_END
10075
5473c134 10076NAME: dns_nameservers
5a1098fb 10077TYPE: SBufList
5473c134 10078DEFAULT: none
638402dd 10079DEFAULT_DOC: Use operating system definitions
5a1098fb 10080LOC: Config.dns.nameservers
cccac0a2 10081DOC_START
5473c134 10082 Use this if you want to specify a list of DNS name servers
10083 (IP addresses) to use instead of those given in your
10084 /etc/resolv.conf file.
638402dd 10085
5473c134 10086 On Windows platforms, if no value is specified here or in
10087 the /etc/resolv.conf file, the list of DNS name servers are
10088 taken from the Windows registry, both static and dynamic DHCP
10089 configurations are supported.
cccac0a2 10090
5473c134 10091 Example: dns_nameservers 10.0.0.1 192.172.0.4
cccac0a2 10092DOC_END
10093
5473c134 10094NAME: hosts_file
cccac0a2 10095TYPE: string
5473c134 10096DEFAULT: @DEFAULT_HOSTS@
10097LOC: Config.etcHostsPath
cccac0a2 10098DOC_START
5473c134 10099 Location of the host-local IP name-address associations
10100 database. Most Operating Systems have such a file on different
10101 default locations:
10102 - Un*X & Linux: /etc/hosts
10103 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
10104 (%SystemRoot% value install default is c:\winnt)
10105 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
10106 (%SystemRoot% value install default is c:\windows)
10107 - Windows 9x/Me: %windir%\hosts
10108 (%windir% value is usually c:\windows)
10109 - Cygwin: /etc/hosts
cccac0a2 10110
5473c134 10111 The file contains newline-separated definitions, in the
10112 form ip_address_in_dotted_form name [name ...] names are
10113 whitespace-separated. Lines beginning with an hash (#)
10114 character are comments.
cccac0a2 10115
5473c134 10116 The file is checked at startup and upon configuration.
10117 If set to 'none', it won't be checked.
10118 If append_domain is used, that domain will be added to
10119 domain-local (i.e. not containing any dot character) host
10120 definitions.
cccac0a2 10121DOC_END
10122
5473c134 10123NAME: append_domain
10124TYPE: string
10125LOC: Config.appendDomain
10126DEFAULT: none
638402dd 10127DEFAULT_DOC: Use operating system definitions
6a2f3fcf 10128DOC_START
5473c134 10129 Appends local domain name to hostnames without any dots in
10130 them. append_domain must begin with a period.
10131
10132 Be warned there are now Internet names with no dots in
10133 them using only top-domain names, so setting this may
10134 cause some Internet sites to become unavailable.
10135
10136Example:
10137 append_domain .yourdomain.com
6a2f3fcf 10138DOC_END
10139
5473c134 10140NAME: ignore_unknown_nameservers
10141TYPE: onoff
10142LOC: Config.onoff.ignore_unknown_nameservers
df6fd596 10143DEFAULT: on
10144DOC_START
5473c134 10145 By default Squid checks that DNS responses are received
10146 from the same IP addresses they are sent to. If they
10147 don't match, Squid ignores the response and writes a warning
10148 message to cache.log. You can allow responses from unknown
10149 nameservers by setting this option to 'off'.
df6fd596 10150DOC_END
10151
6bc15a4f 10152NAME: ipcache_size
10153COMMENT: (number of entries)
10154TYPE: int
10155DEFAULT: 1024
10156LOC: Config.ipcache.size
638402dd
AJ
10157DOC_START
10158 Maximum number of DNS IP cache entries.
10159DOC_END
6bc15a4f 10160
10161NAME: ipcache_low
10162COMMENT: (percent)
10163TYPE: int
10164DEFAULT: 90
10165LOC: Config.ipcache.low
10166DOC_NONE
10167
10168NAME: ipcache_high
10169COMMENT: (percent)
10170TYPE: int
10171DEFAULT: 95
10172LOC: Config.ipcache.high
10173DOC_START
10174 The size, low-, and high-water marks for the IP cache.
10175DOC_END
10176
10177NAME: fqdncache_size
10178COMMENT: (number of entries)
10179TYPE: int
10180DEFAULT: 1024
10181LOC: Config.fqdncache.size
10182DOC_START
10183 Maximum number of FQDN cache entries.
10184DOC_END
10185
a58ff010 10186COMMENT_START
5473c134 10187 MISCELLANEOUS
a58ff010 10188 -----------------------------------------------------------------------------
10189COMMENT_END
10190
2eceb328
CT
10191NAME: configuration_includes_quoted_values
10192COMMENT: on|off
bde7a8ce
CT
10193TYPE: configuration_includes_quoted_values
10194DEFAULT: off
2eceb328
CT
10195LOC: ConfigParser::RecognizeQuotedValues
10196DOC_START
10197 If set, Squid will recognize each "quoted string" after a configuration
10198 directive as a single parameter. The quotes are stripped before the
10199 parameter value is interpreted or used.
10200 See "Values with spaces, quotes, and other special characters"
10201 section for more details.
10202DOC_END
10203
5473c134 10204NAME: memory_pools
a58ff010 10205COMMENT: on|off
5473c134 10206TYPE: onoff
10207DEFAULT: on
10208LOC: Config.onoff.mem_pools
a58ff010 10209DOC_START
5473c134 10210 If set, Squid will keep pools of allocated (but unused) memory
10211 available for future use. If memory is a premium on your
10212 system and you believe your malloc library outperforms Squid
10213 routines, disable this.
a58ff010 10214DOC_END
10215
5473c134 10216NAME: memory_pools_limit
10217COMMENT: (bytes)
70be1349 10218TYPE: b_int64_t
5473c134 10219DEFAULT: 5 MB
10220LOC: Config.MemPools.limit
ec1245f8 10221DOC_START
5473c134 10222 Used only with memory_pools on:
10223 memory_pools_limit 50 MB
ec1245f8 10224
5473c134 10225 If set to a non-zero value, Squid will keep at most the specified
10226 limit of allocated (but unused) memory in memory pools. All free()
10227 requests that exceed this limit will be handled by your malloc
10228 library. Squid does not pre-allocate any memory, just safe-keeps
10229 objects that otherwise would be free()d. Thus, it is safe to set
10230 memory_pools_limit to a reasonably high value even if your
10231 configuration will use less memory.
ec1245f8 10232
89646bd7 10233 If set to none, Squid will keep all memory it can. That is, there
5473c134 10234 will be no limit on the total amount of memory used for safe-keeping.
ec1245f8 10235
5473c134 10236 To disable memory allocation optimization, do not set
70be1349 10237 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
5473c134 10238
10239 An overhead for maintaining memory pools is not taken into account
10240 when the limit is checked. This overhead is close to four bytes per
10241 object kept. However, pools may actually _save_ memory because of
10242 reduced memory thrashing in your malloc library.
ec1245f8 10243DOC_END
10244
5473c134 10245NAME: forwarded_for
67c06f0d
AJ
10246COMMENT: on|off|transparent|truncate|delete
10247TYPE: string
5473c134 10248DEFAULT: on
10249LOC: opt_forwarded_for
5f8252d2 10250DOC_START
67c06f0d
AJ
10251 If set to "on", Squid will append your client's IP address
10252 in the HTTP requests it forwards. By default it looks like:
5f8252d2 10253
5473c134 10254 X-Forwarded-For: 192.1.2.3
10255
67c06f0d 10256 If set to "off", it will appear as
5473c134 10257
10258 X-Forwarded-For: unknown
67c06f0d
AJ
10259
10260 If set to "transparent", Squid will not alter the
10261 X-Forwarded-For header in any way.
10262
10263 If set to "delete", Squid will delete the entire
10264 X-Forwarded-For header.
10265
10266 If set to "truncate", Squid will remove all existing
dd68402f 10267 X-Forwarded-For entries, and place the client IP as the sole entry.
5f8252d2 10268DOC_END
10269
5473c134 10270NAME: cachemgr_passwd
10271TYPE: cachemgrpasswd
10272DEFAULT: none
638402dd 10273DEFAULT_DOC: No password. Actions which require password are denied.
5473c134 10274LOC: Config.passwd_list
5f8252d2 10275DOC_START
5473c134 10276 Specify passwords for cachemgr operations.
5f8252d2 10277
5473c134 10278 Usage: cachemgr_passwd password action action ...
10279
10280 Some valid actions are (see cache manager menu for a full list):
10281 5min
10282 60min
10283 asndb
10284 authenticator
10285 cbdata
10286 client_list
10287 comm_incoming
10288 config *
10289 counters
10290 delay
10291 digest_stats
10292 dns
10293 events
10294 filedescriptors
10295 fqdncache
10296 histograms
10297 http_headers
10298 info
10299 io
10300 ipcache
10301 mem
10302 menu
10303 netdb
10304 non_peers
10305 objects
10306 offline_toggle *
10307 pconn
10308 peer_select
b360c477 10309 reconfigure *
5473c134 10310 redirector
10311 refresh
10312 server_list
10313 shutdown *
10314 store_digest
10315 storedir
10316 utilization
10317 via_headers
10318 vm_objects
10319
10320 * Indicates actions which will not be performed without a
10321 valid password, others can be performed if not listed here.
10322
10323 To disable an action, set the password to "disable".
10324 To allow performing an action without a password, set the
10325 password to "none".
10326
10327 Use the keyword "all" to set the same password for all actions.
10328
10329Example:
10330 cachemgr_passwd secret shutdown
10331 cachemgr_passwd lesssssssecret info stats/objects
10332 cachemgr_passwd disable all
5f8252d2 10333DOC_END
10334
5473c134 10335NAME: client_db
a58ff010 10336COMMENT: on|off
5473c134 10337TYPE: onoff
10338DEFAULT: on
10339LOC: Config.onoff.client_db
a58ff010 10340DOC_START
5473c134 10341 If you want to disable collecting per-client statistics,
10342 turn off client_db here.
a58ff010 10343DOC_END
10344
5473c134 10345NAME: refresh_all_ims
10346COMMENT: on|off
10347TYPE: onoff
10348DEFAULT: off
10349LOC: Config.onoff.refresh_all_ims
a58ff010 10350DOC_START
5473c134 10351 When you enable this option, squid will always check
10352 the origin server for an update when a client sends an
10353 If-Modified-Since request. Many browsers use IMS
10354 requests when the user requests a reload, and this
10355 ensures those clients receive the latest version.
a58ff010 10356
5473c134 10357 By default (off), squid may return a Not Modified response
10358 based on the age of the cached version.
78e8cfc4 10359DOC_END
10360
5473c134 10361NAME: reload_into_ims
626096be 10362IFDEF: USE_HTTP_VIOLATIONS
12b91c99 10363COMMENT: on|off
5473c134 10364TYPE: onoff
10365DEFAULT: off
10366LOC: Config.onoff.reload_into_ims
12b91c99 10367DOC_START
5473c134 10368 When you enable this option, client no-cache or ``reload''
10369 requests will be changed to If-Modified-Since requests.
10370 Doing this VIOLATES the HTTP standard. Enabling this
10371 feature could make you liable for problems which it
10372 causes.
10373
10374 see also refresh_pattern for a more selective approach.
12b91c99 10375DOC_END
10376
31ef19cd 10377NAME: connect_retries
5473c134 10378TYPE: int
31ef19cd
AJ
10379LOC: Config.connect_retries
10380DEFAULT: 0
638402dd 10381DEFAULT_DOC: Do not retry failed connections.
a58ff010 10382DOC_START
3eebd267
EB
10383 Limits the number of reopening attempts when establishing a single
10384 TCP connection. All these attempts must still complete before the
10385 applicable connection opening timeout expires.
10386
10387 By default and when connect_retries is set to zero, Squid does not
10388 retry failed connection opening attempts.
31ef19cd 10389
3eebd267
EB
10390 The (not recommended) maximum is 10 tries. An attempt to configure a
10391 higher value results in the value of 10 being used (with a warning).
5473c134 10392
3eebd267
EB
10393 Squid may open connections to retry various high-level forwarding
10394 failures. For an outside observer, that activity may look like a
10395 low-level connection reopening attempt, but those high-level retries
10396 are governed by forward_max_tries instead.
5473c134 10397
3eebd267
EB
10398 See also: connect_timeout, forward_timeout, icap_connect_timeout,
10399 ident_timeout, and forward_max_tries.
a58ff010 10400DOC_END
10401
5473c134 10402NAME: retry_on_error
a58ff010 10403TYPE: onoff
5473c134 10404LOC: Config.retry.onerror
a58ff010 10405DEFAULT: off
10406DOC_START
aea8548b
AJ
10407 If set to ON Squid will automatically retry requests when
10408 receiving an error response with status 403 (Forbidden),
10409 500 (Internal Error), 501 or 503 (Service not available).
10410 Status 502 and 504 (Gateway errors) are always retried.
9603207d 10411
aea8548b
AJ
10412 This is mainly useful if you are in a complex cache hierarchy to
10413 work around access control errors.
9603207d 10414
aea8548b
AJ
10415 NOTE: This retry will attempt to find another working destination.
10416 Which is different from the server which just failed.
5f8252d2 10417DOC_END
10418
5473c134 10419NAME: as_whois_server
5f8252d2 10420TYPE: string
5473c134 10421LOC: Config.as_whois_server
10422DEFAULT: whois.ra.net
5f8252d2 10423DOC_START
5473c134 10424 WHOIS server to query for AS numbers. NOTE: AS numbers are
10425 queried only when Squid starts up, not for every request.
5f8252d2 10426DOC_END
10427
5473c134 10428NAME: offline_mode
5f8252d2 10429TYPE: onoff
5473c134 10430LOC: Config.onoff.offline
5f8252d2 10431DEFAULT: off
10432DOC_START
5473c134 10433 Enable this option and Squid will never try to validate cached
10434 objects.
a58ff010 10435DOC_END
10436
5473c134 10437NAME: uri_whitespace
10438TYPE: uri_whitespace
10439LOC: Config.uri_whitespace
10440DEFAULT: strip
a58ff010 10441DOC_START
5473c134 10442 What to do with requests that have whitespace characters in the
10443 URI. Options:
a58ff010 10444
5473c134 10445 strip: The whitespace characters are stripped out of the URL.
82806837
AJ
10446 This is the behavior recommended by RFC2396 and RFC3986
10447 for tolerant handling of generic URI.
10448 NOTE: This is one difference between generic URI and HTTP URLs.
10449
5473c134 10450 deny: The request is denied. The user receives an "Invalid
10451 Request" message.
82806837
AJ
10452 This is the behaviour recommended by RFC2616 for safe
10453 handling of HTTP request URL.
10454
5473c134 10455 allow: The request is allowed and the URI is not changed. The
10456 whitespace characters remain in the URI. Note the
10457 whitespace is passed to redirector processes if they
10458 are in use.
82806837
AJ
10459 Note this may be considered a violation of RFC2616
10460 request parsing where whitespace is prohibited in the
10461 URL field.
10462
5473c134 10463 encode: The request is allowed and the whitespace characters are
82806837
AJ
10464 encoded according to RFC1738.
10465
5473c134 10466 chop: The request is allowed and the URI is chopped at the
82806837
AJ
10467 first whitespace.
10468
10469
10470 NOTE the current Squid implementation of encode and chop violates
10471 RFC2616 by not using a 301 redirect after altering the URL.
5473c134 10472DOC_END
a58ff010 10473
5473c134 10474NAME: chroot
10475TYPE: string
10476LOC: Config.chroot_dir
a58ff010 10477DEFAULT: none
10478DOC_START
9f37c18a 10479 Specifies a directory where Squid should do a chroot() while
2d89f399
HN
10480 initializing. This also causes Squid to fully drop root
10481 privileges after initializing. This means, for example, if you
10482 use a HTTP port less than 1024 and try to reconfigure, you may
10483 get an error saying that Squid can not open the port.
5473c134 10484DOC_END
a58ff010 10485
5473c134 10486NAME: pipeline_prefetch
079a8480
AJ
10487TYPE: pipelinePrefetch
10488LOC: Config.pipeline_max_prefetch
10489DEFAULT: 0
10490DEFAULT_DOC: Do not pre-parse pipelined requests.
a58ff010 10491DOC_START
079a8480
AJ
10492 HTTP clients may send a pipeline of 1+N requests to Squid using a
10493 single connection, without waiting for Squid to respond to the first
10494 of those requests. This option limits the number of concurrent
10495 requests Squid will try to handle in parallel. If set to N, Squid
10496 will try to receive and process up to 1+N requests on the same
10497 connection concurrently.
a58ff010 10498
079a8480 10499 Defaults to 0 (off) for bandwidth management and access logging
5473c134 10500 reasons.
a0e23afd 10501
079a8480
AJ
10502 NOTE: pipelining requires persistent connections to clients.
10503
a0e23afd 10504 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
5473c134 10505DOC_END
a58ff010 10506
5473c134 10507NAME: high_response_time_warning
10508TYPE: int
10509COMMENT: (msec)
10510LOC: Config.warnings.high_rptm
10511DEFAULT: 0
638402dd 10512DEFAULT_DOC: disabled.
5473c134 10513DOC_START
10514 If the one-minute median response time exceeds this value,
10515 Squid prints a WARNING with debug level 0 to get the
10516 administrators attention. The value is in milliseconds.
a58ff010 10517DOC_END
10518
5473c134 10519NAME: high_page_fault_warning
10520TYPE: int
10521LOC: Config.warnings.high_pf
10522DEFAULT: 0
638402dd 10523DEFAULT_DOC: disabled.
cc9f92d4 10524DOC_START
5473c134 10525 If the one-minute average page fault rate exceeds this
10526 value, Squid prints a WARNING with debug level 0 to get
10527 the administrators attention. The value is in page faults
10528 per second.
10529DOC_END
cc9f92d4 10530
5473c134 10531NAME: high_memory_warning
10532TYPE: b_size_t
10533LOC: Config.warnings.high_memory
f2228f3b 10534IFDEF: HAVE_MSTATS&&HAVE_GNUMALLOC_H
904971da 10535DEFAULT: 0 KB
638402dd 10536DEFAULT_DOC: disabled.
5473c134 10537DOC_START
4bf2a476
FC
10538 If the memory usage (as determined by gnumalloc, if available and used)
10539 exceeds this amount, Squid prints a WARNING with debug level 0 to get
5473c134 10540 the administrators attention.
10541DOC_END
4bf2a476 10542# TODO: link high_memory_warning to mempools?
cc9f92d4 10543
5473c134 10544NAME: sleep_after_fork
10545COMMENT: (microseconds)
10546TYPE: int
10547LOC: Config.sleep_after_fork
10548DEFAULT: 0
10549DOC_START
10550 When this is set to a non-zero value, the main Squid process
10551 sleeps the specified number of microseconds after a fork()
10552 system call. This sleep may help the situation where your
10553 system reports fork() failures due to lack of (virtual)
10554 memory. Note, however, if you have a lot of child
10555 processes, these sleep delays will add up and your
10556 Squid will not service requests for some amount of time
10557 until all the child processes have been started.
10558 On Windows value less then 1000 (1 milliseconds) are
10559 rounded to 1000.
cc9f92d4 10560DOC_END
10561
b6696974 10562NAME: windows_ipaddrchangemonitor
7aa9bb3e 10563IFDEF: _SQUID_WINDOWS_
b6696974
GS
10564COMMENT: on|off
10565TYPE: onoff
10566DEFAULT: on
10567LOC: Config.onoff.WIN32_IpAddrChangeMonitor
10568DOC_START
9603207d 10569 On Windows Squid by default will monitor IP address changes and will
b6696974
GS
10570 reconfigure itself after any detected event. This is very useful for
10571 proxies connected to internet with dial-up interfaces.
10572 In some cases (a Proxy server acting as VPN gateway is one) it could be
10573 desiderable to disable this behaviour setting this to 'off'.
10574 Note: after changing this, Squid service must be restarted.
10575DOC_END
10576
a98c2da5
AJ
10577NAME: eui_lookup
10578TYPE: onoff
10579IFDEF: USE_SQUID_EUI
10580DEFAULT: on
10581LOC: Eui::TheConfig.euiLookup
10582DOC_START
10583 Whether to lookup the EUI or MAC address of a connected client.
10584DOC_END
10585
f3f0f563
AJ
10586NAME: max_filedescriptors max_filedesc
10587TYPE: int
10588DEFAULT: 0
cfab2c11 10589DEFAULT_DOC: Use operating system soft limit set by ulimit.
f3f0f563
AJ
10590LOC: Config.max_filedescriptors
10591DOC_START
cfab2c11
D
10592 Set the maximum number of filedescriptors, either below the
10593 operating system default or up to the hard limit.
f3f0f563 10594
cfab2c11
D
10595 Remove from squid.conf to inherit the current ulimit soft
10596 limit setting.
f3f0f563
AJ
10597
10598 Note: Changing this requires a restart of Squid. Also
638402dd 10599 not all I/O types supports large values (eg on Windows).
f3f0f563
AJ
10600DOC_END
10601
ec69bdb2
CT
10602NAME: force_request_body_continuation
10603TYPE: acl_access
10604LOC: Config.accessList.forceRequestBodyContinuation
10605DEFAULT: none
10606DEFAULT_DOC: Deny, unless rules exist in squid.conf.
10607DOC_START
10608 This option controls how Squid handles data upload requests from HTTP
10609 and FTP agents that require a "Please Continue" control message response
10610 to actually send the request body to Squid. It is mostly useful in
10611 adaptation environments.
9603207d 10612
ec69bdb2
CT
10613 When Squid receives an HTTP request with an "Expect: 100-continue"
10614 header or an FTP upload command (e.g., STOR), Squid normally sends the
10615 request headers or FTP command information to an adaptation service (or
10616 peer) and waits for a response. Most adaptation services (and some
10617 broken peers) may not respond to Squid at that stage because they may
10618 decide to wait for the HTTP request body or FTP data transfer. However,
10619 that request body or data transfer may never come because Squid has not
10620 responded with the HTTP 100 or FTP 150 (Please Continue) control message
10621 to the request sender yet!
9603207d 10622
ec69bdb2
CT
10623 An allow match tells Squid to respond with the HTTP 100 or FTP 150
10624 (Please Continue) control message on its own, before forwarding the
10625 request to an adaptation service or peer. Such a response usually forces
10626 the request sender to proceed with sending the body. A deny match tells
10627 Squid to delay that control response until the origin server confirms
10628 that the request body is needed. Delaying is the default behavior.
10629DOC_END
1c2b4465
CT
10630
10631NAME: http_upgrade_request_protocols
10632TYPE: http_upgrade_request_protocols
10633LOC: Config.http_upgrade_request_protocols
10634DEFAULT: none
10635DEFAULT_DOC: Upgrade header dropped, effectively blocking an upgrade attempt.
10636DOC_START
10637 Controls client-initiated and server-confirmed switching from HTTP to
10638 another protocol (or to several protocols) using HTTP Upgrade mechanism
10639 defined in RFC 7230 Section 6.7. Squid itself does not understand the
10640 protocols being upgraded to and participates in the upgraded
10641 communication only as a dumb TCP proxy. Admins should not allow
10642 upgrading to protocols that require a more meaningful proxy
10643 participation.
10644
10645 Usage: http_upgrade_request_protocols <protocol> allow|deny [!]acl ...
10646
10647 The required "protocol" parameter is either an all-caps word OTHER or an
10648 explicit protocol name (e.g. "WebSocket") optionally followed by a slash
10649 and a version token (e.g. "HTTP/3"). Explicit protocol names and
10650 versions are case sensitive.
10651
10652 When an HTTP client sends an Upgrade request header, Squid iterates over
10653 the client-offered protocols and, for each protocol P (with an optional
10654 version V), evaluates the first non-empty set of
10655 http_upgrade_request_protocols rules (if any) from the following list:
10656
10657 * All rules with an explicit protocol name equal to P.
10658 * All rules that use OTHER instead of a protocol name.
10659
10660 In other words, rules using OTHER are considered for protocol P if and
10661 only if there are no rules mentioning P by name.
10662
10663 If both of the above sets are empty, then Squid removes protocol P from
10664 the Upgrade offer.
10665
10666 If the client sent a versioned protocol offer P/X, then explicit rules
10667 referring to the same-name but different-version protocol P/Y are
10668 declared inapplicable. Inapplicable rules are not evaluated (i.e. are
10669 ignored). However, inapplicable rules still belong to the first set of
10670 rules for P.
10671
10672 Within the applicable rule subset, individual rules are evaluated in
10673 their configuration order. If all ACLs of an applicable "allow" rule
10674 match, then the protocol offered by the client is forwarded to the next
10675 hop as is. If all ACLs of an applicable "deny" rule match, then the
10676 offer is dropped. If no applicable rules have matching ACLs, then the
10677 offer is also dropped. The first matching rule also ends rules
10678 evaluation for the offered protocol.
10679
10680 If all client-offered protocols are removed, then Squid forwards the
10681 client request without the Upgrade header. Squid never sends an empty
10682 Upgrade request header.
10683
10684 An Upgrade request header with a value violating HTTP syntax is dropped
10685 and ignored without an attempt to use extractable individual protocol
10686 offers.
10687
10688 Upon receiving an HTTP 101 (Switching Protocols) control message, Squid
10689 checks that the server listed at least one protocol name and sent a
10690 Connection:upgrade response header. Squid does not understand individual
10691 protocol naming and versioning concepts enough to implement stricter
10692 checks, but an admin can restrict HTTP 101 (Switching Protocols)
10693 responses further using http_reply_access. Responses denied by
10694 http_reply_access rules and responses flagged by the internal Upgrade
10695 checks result in HTTP 502 (Bad Gateway) ERR_INVALID_RESP errors and
10696 Squid-to-server connection closures.
10697
10698 If Squid sends an Upgrade request header, and the next hop (e.g., the
10699 origin server) responds with an acceptable HTTP 101 (Switching
10700 Protocols), then Squid forwards that message to the client and becomes
10701 a TCP tunnel.
10702
10703 The presence of an Upgrade request header alone does not preclude cache
10704 lookups. In other words, an Upgrade request might be satisfied from the
10705 cache, using regular HTTP caching rules.
10706
10707 This clause only supports fast acl types.
10708 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
10709
10710 Each of the following groups of configuration lines represents a
10711 separate configuration example:
10712
10713 # never upgrade to protocol Foo; all others are OK
10714 http_upgrade_request_protocols Foo deny all
10715 http_upgrade_request_protocols OTHER allow all
10716
10717 # only allow upgrades to protocol Bar (except for its first version)
10718 http_upgrade_request_protocols Bar/1 deny all
10719 http_upgrade_request_protocols Bar allow all
10720 http_upgrade_request_protocols OTHER deny all # this rule is optional
10721
10722 # only allow upgrades to protocol Baz, and only if Baz is the only offer
10723 acl UpgradeHeaderHasMultipleOffers ...
10724 http_upgrade_request_protocols Baz deny UpgradeHeaderHasMultipleOffers
10725 http_upgrade_request_protocols Baz allow all
10726DOC_END
ec69bdb2 10727
afc753f3
EB
10728NAME: server_pconn_for_nonretriable
10729TYPE: acl_access
10730DEFAULT: none
10731DEFAULT_DOC: Open new connections for forwarding requests Squid cannot retry safely.
10732LOC: Config.accessList.serverPconnForNonretriable
10733DOC_START
10734 This option provides fine-grained control over persistent connection
10735 reuse when forwarding HTTP requests that Squid cannot retry. It is useful
10736 in environments where opening new connections is very expensive
10737 (e.g., all connections are secured with TLS with complex client and server
10738 certificate validation) and race conditions associated with persistent
10739 connections are very rare and/or only cause minor problems.
10740
10741 HTTP prohibits retrying unsafe and non-idempotent requests (e.g., POST).
10742 Squid limitations also prohibit retrying all requests with bodies (e.g., PUT).
10743 By default, when forwarding such "risky" requests, Squid opens a new
10744 connection to the server or cache_peer, even if there is an idle persistent
10745 connection available. When Squid is configured to risk sending a non-retriable
10746 request on a previously used persistent connection, and the server closes
10747 the connection before seeing that risky request, the user gets an error response
10748 from Squid. In most cases, that error response will be HTTP 502 (Bad Gateway)
10749 with ERR_ZERO_SIZE_OBJECT or ERR_WRITE_ERROR (peer connection reset) error detail.
10750
10751 If an allow rule matches, Squid reuses an available idle persistent connection
10752 (if any) for the request that Squid cannot retry. If a deny rule matches, then
10753 Squid opens a new connection for the request that Squid cannot retry.
10754
10755 This option does not affect requests that Squid can retry. They will reuse idle
10756 persistent connections (if any).
10757
10758 This clause only supports fast acl types.
10759 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
10760
10761 Example:
10762 acl SpeedIsWorthTheRisk method POST
10763 server_pconn_for_nonretriable allow SpeedIsWorthTheRisk
10764DOC_END
10765
55622953
CT
10766NAME: happy_eyeballs_connect_timeout
10767COMMENT: (msec)
10768TYPE: int
10769DEFAULT: 250
10770LOC: Config.happyEyeballs.connect_timeout
10771DOC_START
10772 This Happy Eyeballs (RFC 8305) tuning directive specifies the minimum
10773 delay between opening a primary to-server connection and opening a
10774 spare to-server connection for the same master transaction. This delay
10775 is similar to the Connection Attempt Delay in RFC 8305, but it is only
10776 applied to the first spare connection attempt. Subsequent spare
10777 connection attempts use happy_eyeballs_connect_gap, and primary
10778 connection attempts are not artificially delayed at all.
10779
10780 Terminology: The "primary" and "spare" designations are determined by
10781 the order of DNS answers received by Squid: If Squid DNS AAAA query
10782 was answered first, then primary connections are connections to IPv6
10783 peer addresses (while spare connections use IPv4 addresses).
10784 Similarly, if Squid DNS A query was answered first, then primary
10785 connections are connections to IPv4 peer addresses (while spare
10786 connections use IPv6 addresses).
10787
10788 Shorter happy_eyeballs_connect_timeout values reduce master
10789 transaction response time, potentially improving user-perceived
10790 response times (i.e., making user eyeballs happier). Longer delays
10791 reduce both concurrent connection level and server bombardment with
10792 connection requests, potentially improving overall Squid performance
10793 and reducing the chance of being blocked by servers for opening too
10794 many unused connections.
10795
10796 RFC 8305 prohibits happy_eyeballs_connect_timeout values smaller than
10797 10 (milliseconds) to "avoid congestion collapse in the presence of
10798 high packet-loss rates".
10799
10800 The following Happy Eyeballs directives place additional connection
10801 opening restrictions: happy_eyeballs_connect_gap and
10802 happy_eyeballs_connect_limit.
10803DOC_END
10804
10805NAME: happy_eyeballs_connect_gap
10806COMMENT: (msec)
10807TYPE: int
10808DEFAULT: -1
10809DEFAULT_DOC: no artificial delays between spare attempts
10810LOC: Config.happyEyeballs.connect_gap
10811DOC_START
10812 This Happy Eyeballs (RFC 8305) tuning directive specifies the
10813 minimum delay between opening spare to-server connections (to any
10814 server; i.e. across all concurrent master transactions in a Squid
10815 instance). Each SMP worker currently multiplies the configured gap
10816 by the total number of workers so that the combined spare connection
10817 opening rate of a Squid instance obeys the configured limit. The
10818 workers do not coordinate connection openings yet; a micro burst
10819 of spare connection openings may violate the configured gap.
10820
10821 This directive has similar trade-offs as
10822 happy_eyeballs_connect_timeout, but its focus is on limiting traffic
10823 amplification effects for Squid as a whole, while
10824 happy_eyeballs_connect_timeout works on an individual master
10825 transaction level.
10826
10827 The following Happy Eyeballs directives place additional connection
10828 opening restrictions: happy_eyeballs_connect_timeout and
10829 happy_eyeballs_connect_limit. See the former for related terminology.
10830DOC_END
10831
10832NAME: happy_eyeballs_connect_limit
10833TYPE: int
10834DEFAULT: -1
10835DEFAULT_DOC: no artificial limit on the number of concurrent spare attempts
10836LOC: Config.happyEyeballs.connect_limit
10837DOC_START
10838 This Happy Eyeballs (RFC 8305) tuning directive specifies the
10839 maximum number of spare to-server connections (to any server; i.e.
10840 across all concurrent master transactions in a Squid instance).
10841 Each SMP worker gets an equal share of the total limit. However,
10842 the workers do not share the actual connection counts yet, so one
10843 (busier) worker cannot "borrow" spare connection slots from another
10844 (less loaded) worker.
10845
10846 Setting this limit to zero disables concurrent use of primary and
10847 spare TCP connections: Spare connection attempts are made only after
10848 all primary attempts fail. However, Squid would still use the
10849 DNS-related optimizations of the Happy Eyeballs approach.
10850
10851 This directive has similar trade-offs as happy_eyeballs_connect_gap,
10852 but its focus is on limiting Squid overheads, while
10853 happy_eyeballs_connect_gap focuses on the origin server and peer
10854 overheads.
10855
10856 The following Happy Eyeballs directives place additional connection
10857 opening restrictions: happy_eyeballs_connect_timeout and
10858 happy_eyeballs_connect_gap. See the former for related terminology.
10859DOC_END
10860
cccac0a2 10861EOF