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1#
2# SQUID Web Proxy Cache http://www.squid-cache.org/
3# ----------------------------------------------------------
4#
5# Squid is the result of efforts by numerous individuals from
6# the Internet community; see the CONTRIBUTORS file for full
7# details. Many organizations have provided support for Squid's
8# development; see the SPONSORS file for full details. Squid is
9# Copyrighted (C) 2000 by the Regents of the University of
10# California; see the COPYRIGHT file for full details. Squid
11# incorporates software developed and/or copyrighted by other
12# sources; see the CREDITS file for full details.
13#
14# This program is free software; you can redistribute it and/or modify
15# it under the terms of the GNU General Public License as published by
16# the Free Software Foundation; either version 2 of the License, or
17# (at your option) any later version.
18#
19# This program is distributed in the hope that it will be useful,
20# but WITHOUT ANY WARRANTY; without even the implied warranty of
21# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22# GNU General Public License for more details.
23#
24# You should have received a copy of the GNU General Public License
25# along with this program; if not, write to the Free Software
26# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
27#
28
29COMMENT_START
30 WELCOME TO @SQUID@
31 ----------------------------
32
33 This is the documentation for the Squid configuration file.
34 This documentation can also be found online at:
35 http://www.squid-cache.org/Doc/config/
36
37 You may wish to look at the Squid home page and wiki for the
38 FAQ and other documentation:
39 http://www.squid-cache.org/
40 http://wiki.squid-cache.org/SquidFaq
41 http://wiki.squid-cache.org/ConfigExamples
42
43 This documentation shows what the defaults for various directives
44 happen to be. If you don't need to change the default, you should
45 leave the line out of your squid.conf in most cases.
46
47 In some cases "none" refers to no default setting at all,
48 while in other cases it refers to the value of the option
49 - the comments for that keyword indicate if this is the case.
50
51COMMENT_END
52
53COMMENT_START
54 Configuration options can be included using the "include" directive.
55 Include takes a list of files to include. Quoting and wildcards are
56 supported.
57
58 For example,
59
60 include /path/to/included/file/squid.acl.config
61
62 Includes can be nested up to a hard-coded depth of 16 levels.
63 This arbitrary restriction is to prevent recursive include references
64 from causing Squid entering an infinite loop whilst trying to load
65 configuration files.
66
67 Values with byte units
68
69 Squid accepts size units on some size related directives. All
70 such directives are documented with a default value displaying
71 a unit.
72
73 Units accepted by Squid are:
74 bytes - byte
75 KB - Kilobyte (1024 bytes)
76 MB - Megabyte
77 GB - Gigabyte
78
79 Values with spaces, quotes, and other special characters
80
81 Squid supports directive parameters with spaces, quotes, and other
82 special characters. Surround such parameters with "double quotes". Use
83 the configuration_includes_quoted_values directive to enable or
84 disable that support.
85
86 Squid supports reading configuration option parameters from external
87 files using the syntax:
88 parameters("/path/filename")
89 For example:
90 acl whitelist dstdomain parameters("/etc/squid/whitelist.txt")
91
92 Conditional configuration
93
94 If-statements can be used to make configuration directives
95 depend on conditions:
96
97 if <CONDITION>
98 ... regular configuration directives ...
99 [else
100 ... regular configuration directives ...]
101 endif
102
103 The else part is optional. The keywords "if", "else", and "endif"
104 must be typed on their own lines, as if they were regular
105 configuration directives.
106
107 NOTE: An else-if condition is not supported.
108
109 These individual conditions types are supported:
110
111 true
112 Always evaluates to true.
113 false
114 Always evaluates to false.
115 <integer> = <integer>
116 Equality comparison of two integer numbers.
117
118
119 SMP-Related Macros
120
121 The following SMP-related preprocessor macros can be used.
122
123 ${process_name} expands to the current Squid process "name"
124 (e.g., squid1, squid2, or cache1).
125
126 ${process_number} expands to the current Squid process
127 identifier, which is an integer number (e.g., 1, 2, 3) unique
128 across all Squid processes of the current service instance.
129
130 ${service_name} expands into the current Squid service instance
131 name identifier which is provided by -n on the command line.
132
133COMMENT_END
134
135# options still not yet ported from 2.7 to 3.x
136NAME: broken_vary_encoding
137TYPE: obsolete
138DOC_START
139 This option is not yet supported by Squid-3.
140DOC_END
141
142NAME: cache_vary
143TYPE: obsolete
144DOC_START
145 This option is not yet supported by Squid-3.
146DOC_END
147
148NAME: error_map
149TYPE: obsolete
150DOC_START
151 This option is not yet supported by Squid-3.
152DOC_END
153
154NAME: external_refresh_check
155TYPE: obsolete
156DOC_START
157 This option is not yet supported by Squid-3.
158DOC_END
159
160NAME: location_rewrite_program location_rewrite_access location_rewrite_children location_rewrite_concurrency
161TYPE: obsolete
162DOC_START
163 This option is not yet supported by Squid-3.
164DOC_END
165
166NAME: refresh_stale_hit
167TYPE: obsolete
168DOC_START
169 This option is not yet supported by Squid-3.
170DOC_END
171
172# Options removed in 3.5
173NAME: hierarchy_stoplist
174TYPE: obsolete
175DOC_START
176 Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
177DOC_END
178
179NAME: log_access
180TYPE: obsolete
181DOC_START
182 Remove this line. Use acls with access_log directives to control access logging
183DOC_END
184
185NAME: log_icap
186TYPE: obsolete
187DOC_START
188 Remove this line. Use acls with icap_log directives to control icap logging
189DOC_END
190
191# Options Removed in 3.3
192NAME: ignore_ims_on_miss
193TYPE: obsolete
194DOC_START
195 Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
196DOC_END
197
198# Options Removed in 3.2
199NAME: dns_v4_fallback
200TYPE: obsolete
201DOC_START
202 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
203DOC_END
204
205NAME: emulate_httpd_log
206TYPE: obsolete
207DOC_START
208 Replace this with an access_log directive using the format 'common' or 'combined'.
209DOC_END
210
211NAME: forward_log
212TYPE: obsolete
213DOC_START
214 Use a regular access.log with ACL limiting it to MISS events.
215DOC_END
216
217NAME: ftp_list_width
218TYPE: obsolete
219DOC_START
220 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
221DOC_END
222
223NAME: ignore_expect_100
224TYPE: obsolete
225DOC_START
226 Remove this line. The HTTP/1.1 feature is now fully supported by default.
227DOC_END
228
229NAME: log_fqdn
230TYPE: obsolete
231DOC_START
232 Remove this option from your config. To log FQDN use %>A in the log format.
233DOC_END
234
235NAME: log_ip_on_direct
236TYPE: obsolete
237DOC_START
238 Remove this option from your config. To log server or peer names use %<A in the log format.
239DOC_END
240
241NAME: maximum_single_addr_tries
242TYPE: obsolete
243DOC_START
244 Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
245DOC_END
246
247NAME: referer_log referrer_log
248TYPE: obsolete
249DOC_START
250 Replace this with an access_log directive using the format 'referrer'.
251DOC_END
252
253NAME: update_headers
254TYPE: obsolete
255DOC_START
256 Remove this line. The feature is supported by default in storage types where update is implemented.
257DOC_END
258
259NAME: url_rewrite_concurrency
260TYPE: obsolete
261DOC_START
262 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
263DOC_END
264
265NAME: useragent_log
266TYPE: obsolete
267DOC_START
268 Replace this with an access_log directive using the format 'useragent'.
269DOC_END
270
271# Options Removed in 3.1
272NAME: dns_testnames
273TYPE: obsolete
274DOC_START
275 Remove this line. DNS is no longer tested on startup.
276DOC_END
277
278NAME: extension_methods
279TYPE: obsolete
280DOC_START
281 Remove this line. All valid methods for HTTP are accepted by default.
282DOC_END
283
284# 2.7 Options Removed/Replaced in 3.2
285NAME: zero_buffers
286TYPE: obsolete
287DOC_NONE
288
289# 2.7 Options Removed/Replaced in 3.1
290NAME: incoming_rate
291TYPE: obsolete
292DOC_NONE
293
294NAME: server_http11
295TYPE: obsolete
296DOC_START
297 Remove this line. HTTP/1.1 is supported by default.
298DOC_END
299
300NAME: upgrade_http0.9
301TYPE: obsolete
302DOC_START
303 Remove this line. ICY/1.0 streaming protocol is supported by default.
304DOC_END
305
306NAME: zph_local zph_mode zph_option zph_parent zph_sibling
307TYPE: obsolete
308DOC_START
309 Alter these entries. Use the qos_flows directive instead.
310DOC_END
311
312# Options Removed in 3.0
313NAME: header_access
314TYPE: obsolete
315DOC_START
316 Since squid-3.0 replace with request_header_access or reply_header_access
317 depending on whether you wish to match client requests or server replies.
318DOC_END
319
320NAME: httpd_accel_no_pmtu_disc
321TYPE: obsolete
322DOC_START
323 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
324DOC_END
325
326NAME: wais_relay_host
327TYPE: obsolete
328DOC_START
329 Replace this line with 'cache_peer' configuration.
330DOC_END
331
332NAME: wais_relay_port
333TYPE: obsolete
334DOC_START
335 Replace this line with 'cache_peer' configuration.
336DOC_END
337
338COMMENT_START
339 OPTIONS FOR AUTHENTICATION
340 -----------------------------------------------------------------------------
341COMMENT_END
342
343NAME: auth_param
344TYPE: authparam
345IFDEF: USE_AUTH
346LOC: Auth::TheConfig
347DEFAULT: none
348DOC_START
349 This is used to define parameters for the various authentication
350 schemes supported by Squid.
351
352 format: auth_param scheme parameter [setting]
353
354 The order in which authentication schemes are presented to the client is
355 dependent on the order the scheme first appears in config file. IE
356 has a bug (it's not RFC 2617 compliant) in that it will use the basic
357 scheme if basic is the first entry presented, even if more secure
358 schemes are presented. For now use the order in the recommended
359 settings section below. If other browsers have difficulties (don't
360 recognize the schemes offered even if you are using basic) either
361 put basic first, or disable the other schemes (by commenting out their
362 program entry).
363
364 Once an authentication scheme is fully configured, it can only be
365 shutdown by shutting squid down and restarting. Changes can be made on
366 the fly and activated with a reconfigure. I.E. You can change to a
367 different helper, but not unconfigure the helper completely.
368
369 Please note that while this directive defines how Squid processes
370 authentication it does not automatically activate authentication.
371 To use authentication you must in addition make use of ACLs based
372 on login name in http_access (proxy_auth, proxy_auth_regex or
373 external with %LOGIN used in the format tag). The browser will be
374 challenged for authentication on the first such acl encountered
375 in http_access processing and will also be re-challenged for new
376 login credentials if the request is being denied by a proxy_auth
377 type acl.
378
379 WARNING: authentication can't be used in a transparently intercepting
380 proxy as the client then thinks it is talking to an origin server and
381 not the proxy. This is a limitation of bending the TCP/IP protocol to
382 transparently intercepting port 80, not a limitation in Squid.
383 Ports flagged 'transparent', 'intercept', or 'tproxy' have
384 authentication disabled.
385
386 === Parameters common to all schemes. ===
387
388 "program" cmdline
389 Specifies the command for the external authenticator.
390
391 By default, each authentication scheme is not used unless a
392 program is specified.
393
394 See http://wiki.squid-cache.org/Features/AddonHelpers for
395 more details on helper operations and creating your own.
396
397 "key_extras" format
398 Specifies a string to be append to request line format for
399 the authentication helper. "Quoted" format values may contain
400 spaces and logformat %macros. In theory, any logformat %macro
401 can be used. In practice, a %macro expands as a dash (-) if
402 the helper request is sent before the required macro
403 information is available to Squid.
404
405 By default, Squid uses request formats provided in
406 scheme-specific examples below (search for %credentials).
407
408 The expanded key_extras value is added to the Squid credentials
409 cache and, hence, will affect authentication. It can be used to
410 autenticate different users with identical user names (e.g.,
411 when user authentication depends on http_port).
412
413 Avoid adding frequently changing information to key_extras. For
414 example, if you add user source IP, and it changes frequently
415 in your environment, then max_user_ip ACL is going to treat
416 every user+IP combination as a unique "user", breaking the ACL
417 and wasting a lot of memory on those user records. It will also
418 force users to authenticate from scratch whenever their IP
419 changes.
420
421 "realm" string
422 Specifies the protection scope (aka realm name) which is to be
423 reported to the client for the authentication scheme. It is
424 commonly part of the text the user will see when prompted for
425 their username and password.
426
427 For Basic the default is "Squid proxy-caching web server".
428 For Digest there is no default, this parameter is mandatory.
429 For NTLM and Negotiate this parameter is ignored.
430
431 "children" numberofchildren [startup=N] [idle=N] [concurrency=N] [queue-size=N]
432
433 The maximum number of authenticator processes to spawn. If
434 you start too few Squid will have to wait for them to process
435 a backlog of credential verifications, slowing it down. When
436 password verifications are done via a (slow) network you are
437 likely to need lots of authenticator processes.
438
439 The startup= and idle= options permit some skew in the exact
440 amount run. A minimum of startup=N will begin during startup
441 and reconfigure. Squid will start more in groups of up to
442 idle=N in an attempt to meet traffic needs and to keep idle=N
443 free above those traffic needs up to the maximum.
444
445 The concurrency= option sets the number of concurrent requests
446 the helper can process. The default of 0 is used for helpers
447 who only supports one request at a time. Setting this to a
448 number greater than 0 changes the protocol used to include a
449 channel ID field first on the request/response line, allowing
450 multiple requests to be sent to the same helper in parallel
451 without waiting for the response.
452
453 Concurrency must not be set unless it's known the helper
454 supports the input format with channel-ID fields.
455
456 The queue-size= option sets the maximum number of queued
457 requests. If the queued requests exceed queue size for more
458 than 3 minutes then squid aborts its operation.
459 The default value is set to 2*numberofchildren/
460
461 NOTE: NTLM and Negotiate schemes do not support concurrency
462 in the Squid code module even though some helpers can.
463
464
465IF HAVE_AUTH_MODULE_BASIC
466 === Basic authentication parameters ===
467
468 "utf8" on|off
469 HTTP uses iso-latin-1 as character set, while some
470 authentication backends such as LDAP expects UTF-8. If this is
471 set to on Squid will translate the HTTP iso-latin-1 charset to
472 UTF-8 before sending the username and password to the helper.
473
474 "credentialsttl" timetolive
475 Specifies how long squid assumes an externally validated
476 username:password pair is valid for - in other words how
477 often the helper program is called for that user. Set this
478 low to force revalidation with short lived passwords.
479
480 NOTE: setting this high does not impact your susceptibility
481 to replay attacks unless you are using an one-time password
482 system (such as SecureID). If you are using such a system,
483 you will be vulnerable to replay attacks unless you also
484 use the max_user_ip ACL in an http_access rule.
485
486 "casesensitive" on|off
487 Specifies if usernames are case sensitive. Most user databases
488 are case insensitive allowing the same username to be spelled
489 using both lower and upper case letters, but some are case
490 sensitive. This makes a big difference for user_max_ip ACL
491 processing and similar.
492
493ENDIF
494IF HAVE_AUTH_MODULE_DIGEST
495 === Digest authentication parameters ===
496
497 "utf8" on|off
498 HTTP uses iso-latin-1 as character set, while some
499 authentication backends such as LDAP expects UTF-8. If this is
500 set to on Squid will translate the HTTP iso-latin-1 charset to
501 UTF-8 before sending the username and password to the helper.
502
503 "nonce_garbage_interval" timeinterval
504 Specifies the interval that nonces that have been issued
505 to client_agent's are checked for validity.
506
507 "nonce_max_duration" timeinterval
508 Specifies the maximum length of time a given nonce will be
509 valid for.
510
511 "nonce_max_count" number
512 Specifies the maximum number of times a given nonce can be
513 used.
514
515 "nonce_strictness" on|off
516 Determines if squid requires strict increment-by-1 behavior
517 for nonce counts, or just incrementing (off - for use when
518 user agents generate nonce counts that occasionally miss 1
519 (ie, 1,2,4,6)). Default off.
520
521 "check_nonce_count" on|off
522 This directive if set to off can disable the nonce count check
523 completely to work around buggy digest qop implementations in
524 certain mainstream browser versions. Default on to check the
525 nonce count to protect from authentication replay attacks.
526
527 "post_workaround" on|off
528 This is a workaround to certain buggy browsers who send an
529 incorrect request digest in POST requests when reusing the
530 same nonce as acquired earlier on a GET request.
531
532ENDIF
533IF HAVE_AUTH_MODULE_NEGOTIATE
534 === Negotiate authentication parameters ===
535
536 "keep_alive" on|off
537 If you experience problems with PUT/POST requests when using
538 the this authentication scheme then you can try setting this
539 to off. This will cause Squid to forcibly close the connection
540 on the initial request where the browser asks which schemes
541 are supported by the proxy.
542
543ENDIF
544IF HAVE_AUTH_MODULE_NTLM
545 === NTLM authentication parameters ===
546
547 "keep_alive" on|off
548 If you experience problems with PUT/POST requests when using
549 the this authentication scheme then you can try setting this
550 to off. This will cause Squid to forcibly close the connection
551 on the initial request where the browser asks which schemes
552 are supported by the proxy.
553ENDIF
554
555 === Example Configuration ===
556
557 This configuration displays the recommended authentication scheme
558 order from most to least secure with recommended minimum configuration
559 settings for each scheme:
560
561#auth_param negotiate program <uncomment and complete this line to activate>
562#auth_param negotiate children 20 startup=0 idle=1
563#auth_param negotiate keep_alive on
564#
565#auth_param digest program <uncomment and complete this line to activate>
566#auth_param digest children 20 startup=0 idle=1
567#auth_param digest realm Squid proxy-caching web server
568#auth_param digest nonce_garbage_interval 5 minutes
569#auth_param digest nonce_max_duration 30 minutes
570#auth_param digest nonce_max_count 50
571#
572#auth_param ntlm program <uncomment and complete this line to activate>
573#auth_param ntlm children 20 startup=0 idle=1
574#auth_param ntlm keep_alive on
575#
576#auth_param basic program <uncomment and complete this line>
577#auth_param basic children 5 startup=5 idle=1
578#auth_param basic realm Squid proxy-caching web server
579#auth_param basic credentialsttl 2 hours
580DOC_END
581
582NAME: authenticate_cache_garbage_interval
583TYPE: time_t
584DEFAULT: 1 hour
585LOC: Config.authenticateGCInterval
586DOC_START
587 The time period between garbage collection across the username cache.
588 This is a trade-off between memory utilization (long intervals - say
589 2 days) and CPU (short intervals - say 1 minute). Only change if you
590 have good reason to.
591DOC_END
592
593NAME: authenticate_ttl
594TYPE: time_t
595DEFAULT: 1 hour
596LOC: Config.authenticateTTL
597DOC_START
598 The time a user & their credentials stay in the logged in
599 user cache since their last request. When the garbage
600 interval passes, all user credentials that have passed their
601 TTL are removed from memory.
602DOC_END
603
604NAME: authenticate_ip_ttl
605TYPE: time_t
606LOC: Config.authenticateIpTTL
607DEFAULT: 1 second
608DOC_START
609 If you use proxy authentication and the 'max_user_ip' ACL,
610 this directive controls how long Squid remembers the IP
611 addresses associated with each user. Use a small value
612 (e.g., 60 seconds) if your users might change addresses
613 quickly, as is the case with dialup. You might be safe
614 using a larger value (e.g., 2 hours) in a corporate LAN
615 environment with relatively static address assignments.
616DOC_END
617
618COMMENT_START
619 ACCESS CONTROLS
620 -----------------------------------------------------------------------------
621COMMENT_END
622
623NAME: external_acl_type
624TYPE: externalAclHelper
625LOC: Config.externalAclHelperList
626DEFAULT: none
627DOC_START
628 This option defines external acl classes using a helper program
629 to look up the status
630
631 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
632
633 Options:
634
635 ttl=n TTL in seconds for cached results (defaults to 3600
636 for 1 hour)
637
638 negative_ttl=n
639 TTL for cached negative lookups (default same
640 as ttl)
641
642 grace=n Percentage remaining of TTL where a refresh of a
643 cached entry should be initiated without needing to
644 wait for a new reply. (default is for no grace period)
645
646 cache=n Limit the result cache size, default is 262144.
647 The expanded FORMAT value is used as the cache key, so
648 if the details in FORMAT are highly variable a larger
649 cache may be needed to produce reduction in helper load.
650
651 children-max=n
652 Maximum number of acl helper processes spawned to service
653 external acl lookups of this type. (default 20)
654
655 children-startup=n
656 Minimum number of acl helper processes to spawn during
657 startup and reconfigure to service external acl lookups
658 of this type. (default 0)
659
660 children-idle=n
661 Number of acl helper processes to keep ahead of traffic
662 loads. Squid will spawn this many at once whenever load
663 rises above the capabilities of existing processes.
664 Up to the value of children-max. (default 1)
665
666 concurrency=n concurrency level per process. Only used with helpers
667 capable of processing more than one query at a time.
668
669 queue-size=N The queue-size= option sets the maximum number of queued
670 requests. If the queued requests exceed queue size
671 the acl is ignored.
672 The default value is set to 2*children-max.
673
674 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers.
675
676 ipv4 / ipv6 IP protocol used to communicate with this helper.
677 The default is to auto-detect IPv6 and use it when available.
678
679
680 FORMAT specifications
681
682 %LOGIN Authenticated user login name
683 %EXT_USER Username from previous external acl
684 %EXT_LOG Log details from previous external acl
685 %EXT_TAG Tag from previous external acl
686 %IDENT Ident user name
687 %SRC Client IP
688 %SRCPORT Client source port
689 %URI Requested URI
690 %DST Requested host
691 %PROTO Requested URL scheme
692 %PORT Requested port
693 %PATH Requested URL path
694 %METHOD Request method
695 %MYADDR Squid interface address
696 %MYPORT Squid http_port number
697 %PATH Requested URL-path (including query-string if any)
698 %USER_CERT SSL User certificate in PEM format
699 %USER_CERTCHAIN SSL User certificate chain in PEM format
700 %USER_CERT_xx SSL User certificate subject attribute xx
701 %USER_CA_CERT_xx SSL User certificate issuer attribute xx
702 %ssl::>sni SSL client SNI sent to Squid
703 %ssl::<cert_subject SSL server certificate DN
704 %ssl::<cert_issuer SSL server certificate issuer DN
705
706 %>{Header} HTTP request header "Header"
707 %>{Hdr:member}
708 HTTP request header "Hdr" list member "member"
709 %>{Hdr:;member}
710 HTTP request header list member using ; as
711 list separator. ; can be any non-alphanumeric
712 character.
713
714 %<{Header} HTTP reply header "Header"
715 %<{Hdr:member}
716 HTTP reply header "Hdr" list member "member"
717 %<{Hdr:;member}
718 HTTP reply header list member using ; as
719 list separator. ; can be any non-alphanumeric
720 character.
721
722 %ACL The name of the ACL being tested.
723 %DATA The ACL arguments. If not used then any arguments
724 is automatically added at the end of the line
725 sent to the helper.
726 NOTE: this will encode the arguments as one token,
727 whereas the default will pass each separately.
728
729 %% The percent sign. Useful for helpers which need
730 an unchanging input format.
731
732
733 General request syntax:
734
735 [channel-ID] FORMAT-values [acl-values ...]
736
737
738 FORMAT-values consists of transaction details expanded with
739 whitespace separation per the config file FORMAT specification
740 using the FORMAT macros listed above.
741
742 acl-values consists of any string specified in the referencing
743 config 'acl ... external' line. see the "acl external" directive.
744
745 Request values sent to the helper are URL escaped to protect
746 each value in requests against whitespaces.
747
748 If using protocol=2.5 then the request sent to the helper is not
749 URL escaped to protect against whitespace.
750
751 NOTE: protocol=3.0 is deprecated as no longer necessary.
752
753 When using the concurrency= option the protocol is changed by
754 introducing a query channel tag in front of the request/response.
755 The query channel tag is a number between 0 and concurrency-1.
756 This value must be echoed back unchanged to Squid as the first part
757 of the response relating to its request.
758
759
760 The helper receives lines expanded per the above format specification
761 and for each input line returns 1 line starting with OK/ERR/BH result
762 code and optionally followed by additional keywords with more details.
763
764
765 General result syntax:
766
767 [channel-ID] result keyword=value ...
768
769 Result consists of one of the codes:
770
771 OK
772 the ACL test produced a match.
773
774 ERR
775 the ACL test does not produce a match.
776
777 BH
778 An internal error occurred in the helper, preventing
779 a result being identified.
780
781 The meaning of 'a match' is determined by your squid.conf
782 access control configuration. See the Squid wiki for details.
783
784 Defined keywords:
785
786 user= The users name (login)
787
788 password= The users password (for login= cache_peer option)
789
790 message= Message describing the reason for this response.
791 Available as %o in error pages.
792 Useful on (ERR and BH results).
793
794 tag= Apply a tag to a request. Only sets a tag once,
795 does not alter existing tags.
796
797 log= String to be logged in access.log. Available as
798 %ea in logformat specifications.
799
800 clt_conn_tag= Associates a TAG with the client TCP connection.
801 Please see url_rewrite_program related documentation
802 for this kv-pair.
803
804 Any keywords may be sent on any response whether OK, ERR or BH.
805
806 All response keyword values need to be a single token with URL
807 escaping, or enclosed in double quotes (") and escaped using \ on
808 any double quotes or \ characters within the value. The wrapping
809 double quotes are removed before the value is interpreted by Squid.
810 \r and \n are also replace by CR and LF.
811
812 Some example key values:
813
814 user=John%20Smith
815 user="John Smith"
816 user="J. \"Bob\" Smith"
817DOC_END
818
819NAME: acl
820TYPE: acl
821LOC: Config.aclList
822IF USE_OPENSSL
823DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
824DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
825DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
826DEFAULT: 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
827DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
828ENDIF
829DEFAULT: all src all
830DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
831DEFAULT: localhost src 127.0.0.1/32 ::1
832DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
833DEFAULT_DOC: ACLs all, manager, localhost, and to_localhost are predefined.
834DOC_START
835 Defining an Access List
836
837 Every access list definition must begin with an aclname and acltype,
838 followed by either type-specific arguments or a quoted filename that
839 they are read from.
840
841 acl aclname acltype argument ...
842 acl aclname acltype "file" ...
843
844 When using "file", the file should contain one item per line.
845
846 Some acl types supports options which changes their default behaviour.
847 The available options are:
848
849 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
850 case-insensitive, use the -i option. To return case-sensitive
851 use the +i option between patterns, or make a new ACL line
852 without -i.
853
854 -n Disable lookups and address type conversions. If lookup or
855 conversion is required because the parameter type (IP or
856 domain name) does not match the message address type (domain
857 name or IP), then the ACL would immediately declare a mismatch
858 without any warnings or lookups.
859
860 -- Used to stop processing all options, in the case the first acl
861 value has '-' character as first character (for example the '-'
862 is a valid domain name)
863
864 Some acl types require suspending the current request in order
865 to access some external data source.
866 Those which do are marked with the tag [slow], those which
867 don't are marked as [fast].
868 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
869 for further information
870
871 ***** ACL TYPES AVAILABLE *****
872
873 acl aclname src ip-address/mask ... # clients IP address [fast]
874 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
875 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
876 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
877
878 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
879 # The arp ACL requires the special configure option --enable-arp-acl.
880 # Furthermore, the ARP ACL code is not portable to all operating systems.
881 # It works on Linux, Solaris, Windows, FreeBSD, and some
882 # other *BSD variants.
883 # [fast]
884 #
885 # NOTE: Squid can only determine the MAC address for clients that are on
886 # the same subnet. If the client is on a different subnet,
887 # then Squid cannot find out its MAC address.
888
889 acl aclname srcdomain .foo.com ...
890 # reverse lookup, from client IP [slow]
891 acl aclname dstdomain [-n] .foo.com ...
892 # Destination server from URL [fast]
893 acl aclname srcdom_regex [-i] \.foo\.com ...
894 # regex matching client name [slow]
895 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
896 # regex matching server [fast]
897 #
898 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
899 # based URL is used and no match is found. The name "none" is used
900 # if the reverse lookup fails.
901
902 acl aclname src_as number ...
903 acl aclname dst_as number ...
904 # [fast]
905 # Except for access control, AS numbers can be used for
906 # routing of requests to specific caches. Here's an
907 # example for routing all requests for AS#1241 and only
908 # those to mycache.mydomain.net:
909 # acl asexample dst_as 1241
910 # cache_peer_access mycache.mydomain.net allow asexample
911 # cache_peer_access mycache_mydomain.net deny all
912
913 acl aclname peername myPeer ...
914 # [fast]
915 # match against a named cache_peer entry
916 # set unique name= on cache_peer lines for reliable use.
917
918 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
919 # [fast]
920 # day-abbrevs:
921 # S - Sunday
922 # M - Monday
923 # T - Tuesday
924 # W - Wednesday
925 # H - Thursday
926 # F - Friday
927 # A - Saturday
928 # h1:m1 must be less than h2:m2
929
930 acl aclname url_regex [-i] ^http:// ...
931 # regex matching on whole URL [fast]
932 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
933 # regex matching on URL login field
934 acl aclname urlpath_regex [-i] \.gif$ ...
935 # regex matching on URL path [fast]
936
937 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
938 # ranges are alloed
939 acl aclname localport 3128 ... # TCP port the client connected to [fast]
940 # NP: for interception mode this is usually '80'
941
942 acl aclname myportname 3128 ... # *_port name [fast]
943
944 acl aclname proto HTTP FTP ... # request protocol [fast]
945
946 acl aclname method GET POST ... # HTTP request method [fast]
947
948 acl aclname http_status 200 301 500- 400-403 ...
949 # status code in reply [fast]
950
951 acl aclname browser [-i] regexp ...
952 # pattern match on User-Agent header (see also req_header below) [fast]
953
954 acl aclname referer_regex [-i] regexp ...
955 # pattern match on Referer header [fast]
956 # Referer is highly unreliable, so use with care
957
958 acl aclname ident username ...
959 acl aclname ident_regex [-i] pattern ...
960 # string match on ident output [slow]
961 # use REQUIRED to accept any non-null ident.
962
963 acl aclname proxy_auth [-i] username ...
964 acl aclname proxy_auth_regex [-i] pattern ...
965 # perform http authentication challenge to the client and match against
966 # supplied credentials [slow]
967 #
968 # takes a list of allowed usernames.
969 # use REQUIRED to accept any valid username.
970 #
971 # Will use proxy authentication in forward-proxy scenarios, and plain
972 # http authenticaiton in reverse-proxy scenarios
973 #
974 # NOTE: when a Proxy-Authentication header is sent but it is not
975 # needed during ACL checking the username is NOT logged
976 # in access.log.
977 #
978 # NOTE: proxy_auth requires a EXTERNAL authentication program
979 # to check username/password combinations (see
980 # auth_param directive).
981 #
982 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
983 # as the browser needs to be configured for using a proxy in order
984 # to respond to proxy authentication.
985
986 acl aclname snmp_community string ...
987 # A community string to limit access to your SNMP Agent [fast]
988 # Example:
989 #
990 # acl snmppublic snmp_community public
991
992 acl aclname maxconn number
993 # This will be matched when the client's IP address has
994 # more than <number> TCP connections established. [fast]
995 # NOTE: This only measures direct TCP links so X-Forwarded-For
996 # indirect clients are not counted.
997
998 acl aclname max_user_ip [-s] number
999 # This will be matched when the user attempts to log in from more
1000 # than <number> different ip addresses. The authenticate_ip_ttl
1001 # parameter controls the timeout on the ip entries. [fast]
1002 # If -s is specified the limit is strict, denying browsing
1003 # from any further IP addresses until the ttl has expired. Without
1004 # -s Squid will just annoy the user by "randomly" denying requests.
1005 # (the counter is reset each time the limit is reached and a
1006 # request is denied)
1007 # NOTE: in acceleration mode or where there is mesh of child proxies,
1008 # clients may appear to come from multiple addresses if they are
1009 # going through proxy farms, so a limit of 1 may cause user problems.
1010
1011 acl aclname random probability
1012 # Pseudo-randomly match requests. Based on the probability given.
1013 # Probability may be written as a decimal (0.333), fraction (1/3)
1014 # or ratio of matches:non-matches (3:5).
1015
1016 acl aclname req_mime_type [-i] mime-type ...
1017 # regex match against the mime type of the request generated
1018 # by the client. Can be used to detect file upload or some
1019 # types HTTP tunneling requests [fast]
1020 # NOTE: This does NOT match the reply. You cannot use this
1021 # to match the returned file type.
1022
1023 acl aclname req_header header-name [-i] any\.regex\.here
1024 # regex match against any of the known request headers. May be
1025 # thought of as a superset of "browser", "referer" and "mime-type"
1026 # ACL [fast]
1027
1028 acl aclname rep_mime_type [-i] mime-type ...
1029 # regex match against the mime type of the reply received by
1030 # squid. Can be used to detect file download or some
1031 # types HTTP tunneling requests. [fast]
1032 # NOTE: This has no effect in http_access rules. It only has
1033 # effect in rules that affect the reply data stream such as
1034 # http_reply_access.
1035
1036 acl aclname rep_header header-name [-i] any\.regex\.here
1037 # regex match against any of the known reply headers. May be
1038 # thought of as a superset of "browser", "referer" and "mime-type"
1039 # ACLs [fast]
1040
1041 acl aclname external class_name [arguments...]
1042 # external ACL lookup via a helper class defined by the
1043 # external_acl_type directive [slow]
1044
1045 acl aclname user_cert attribute values...
1046 # match against attributes in a user SSL certificate
1047 # attribute is one of DN/C/O/CN/L/ST [fast]
1048
1049 acl aclname ca_cert attribute values...
1050 # match against attributes a users issuing CA SSL certificate
1051 # attribute is one of DN/C/O/CN/L/ST [fast]
1052
1053 acl aclname ext_user username ...
1054 acl aclname ext_user_regex [-i] pattern ...
1055 # string match on username returned by external acl helper [slow]
1056 # use REQUIRED to accept any non-null user name.
1057
1058 acl aclname tag tagvalue ...
1059 # string match on tag returned by external acl helper [fast]
1060 # DEPRECATED. Only the first tag will match with this ACL.
1061 # Use the 'note' ACL instead for handling multiple tag values.
1062
1063 acl aclname hier_code codename ...
1064 # string match against squid hierarchy code(s); [fast]
1065 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1066 #
1067 # NOTE: This has no effect in http_access rules. It only has
1068 # effect in rules that affect the reply data stream such as
1069 # http_reply_access.
1070
1071 acl aclname note name [value ...]
1072 # match transaction annotation [fast]
1073 # Without values, matches any annotation with a given name.
1074 # With value(s), matches any annotation with a given name that
1075 # also has one of the given values.
1076 # Names and values are compared using a string equality test.
1077 # Annotation sources include note and adaptation_meta directives
1078 # as well as helper and eCAP responses.
1079
1080 acl aclname adaptation_service service ...
1081 # Matches the name of any icap_service, ecap_service,
1082 # adaptation_service_set, or adaptation_service_chain that Squid
1083 # has used (or attempted to use) for the master transaction.
1084 # This ACL must be defined after the corresponding adaptation
1085 # service is named in squid.conf. This ACL is usable with
1086 # adaptation_meta because it starts matching immediately after
1087 # the service has been selected for adaptation.
1088
1089IF USE_OPENSSL
1090 acl aclname ssl_error errorname
1091 # match against SSL certificate validation error [fast]
1092 #
1093 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1094 # template file.
1095 #
1096 # The following can be used as shortcuts for certificate properties:
1097 # [ssl::]certHasExpired: the "not after" field is in the past
1098 # [ssl::]certNotYetValid: the "not before" field is in the future
1099 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1100 # [ssl::]certSelfSigned: The certificate is self signed.
1101 # [ssl::]certDomainMismatch: The certificate CN domain does not
1102 # match the name the name of the host we are connecting to.
1103 #
1104 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1105 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1106 # predefined ACLs, just like the 'all' ACL.
1107 #
1108 # NOTE: The ssl_error ACL is only supported with sslproxy_cert_error,
1109 # sslproxy_cert_sign, and sslproxy_cert_adapt options.
1110
1111 acl aclname server_cert_fingerprint [-sha1] fingerprint
1112 # match against server SSL certificate fingerprint [fast]
1113 #
1114 # The fingerprint is the digest of the DER encoded version
1115 # of the whole certificate. The user should use the form: XX:XX:...
1116 # Optional argument specifies the digest algorithm to use.
1117 # The SHA1 digest algorithm is the default and is currently
1118 # the only algorithm supported (-sha1).
1119
1120 acl aclname at_step step
1121 # match against the current step during ssl_bump evaluation [fast]
1122 # Never matches and should not be used outside the ssl_bump context.
1123 #
1124 # At each SslBump step, Squid evaluates ssl_bump directives to find
1125 # the next bumping action (e.g., peek or splice). Valid SslBump step
1126 # values and the corresponding ssl_bump evaluation moments are:
1127 # SslBump1: After getting TCP-level and HTTP CONNECT info.
1128 # SslBump2: After getting SSL Client Hello info.
1129 # SslBump3: After getting SSL Server Hello info.
1130ENDIF
1131 acl aclname any-of acl1 acl2 ...
1132 # match any one of the acls [fast or slow]
1133 # The first matching ACL stops further ACL evaluation.
1134 #
1135 # ACLs from multiple any-of lines with the same name are ORed.
1136 # For example, A = (a1 or a2) or (a3 or a4) can be written as
1137 # acl A any-of a1 a2
1138 # acl A any-of a3 a4
1139 #
1140 # This group ACL is fast if all evaluated ACLs in the group are fast
1141 # and slow otherwise.
1142
1143 acl aclname all-of acl1 acl2 ...
1144 # match all of the acls [fast or slow]
1145 # The first mismatching ACL stops further ACL evaluation.
1146 #
1147 # ACLs from multiple all-of lines with the same name are ORed.
1148 # For example, B = (b1 and b2) or (b3 and b4) can be written as
1149 # acl B all-of b1 b2
1150 # acl B all-of b3 b4
1151 #
1152 # This group ACL is fast if all evaluated ACLs in the group are fast
1153 # and slow otherwise.
1154
1155 Examples:
1156 acl macaddress arp 09:00:2b:23:45:67
1157 acl myexample dst_as 1241
1158 acl password proxy_auth REQUIRED
1159 acl fileupload req_mime_type -i ^multipart/form-data$
1160 acl javascript rep_mime_type -i ^application/x-javascript$
1161
1162NOCOMMENT_START
1163#
1164# Recommended minimum configuration:
1165#
1166
1167# Example rule allowing access from your local networks.
1168# Adapt to list your (internal) IP networks from where browsing
1169# should be allowed
1170acl localnet src 0.0.0.1-0.255.255.255 # RFC 1122 "this" network (LAN)
1171acl localnet src 10.0.0.0/8 # RFC 1918 local private network (LAN)
1172acl localnet src 100.64.0.0/10 # RFC 6598 shared address space (CGN)
1173acl localhet src 169.254.0.0/16 # RFC 3927 link-local (directly plugged) machines
1174acl localnet src 172.16.0.0/12 # RFC 1918 local private network (LAN)
1175acl localnet src 192.168.0.0/16 # RFC 1918 local private network (LAN)
1176acl localnet src fc00::/7 # RFC 4193 local private network range
1177acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1178
1179acl SSL_ports port 443
1180acl Safe_ports port 80 # http
1181acl Safe_ports port 21 # ftp
1182acl Safe_ports port 443 # https
1183acl Safe_ports port 70 # gopher
1184acl Safe_ports port 210 # wais
1185acl Safe_ports port 1025-65535 # unregistered ports
1186acl Safe_ports port 280 # http-mgmt
1187acl Safe_ports port 488 # gss-http
1188acl Safe_ports port 591 # filemaker
1189acl Safe_ports port 777 # multiling http
1190acl CONNECT method CONNECT
1191NOCOMMENT_END
1192DOC_END
1193
1194NAME: proxy_protocol_access
1195TYPE: acl_access
1196LOC: Config.accessList.proxyProtocol
1197DEFAULT: none
1198DEFAULT_DOC: all TCP connections to ports with require-proxy-header will be denied
1199DOC_START
1200 Determine which client proxies can be trusted to provide correct
1201 information regarding real client IP address using PROXY protocol.
1202
1203 Requests may pass through a chain of several other proxies
1204 before reaching us. The original source details may by sent in:
1205 * HTTP message Forwarded header, or
1206 * HTTP message X-Forwarded-For header, or
1207 * PROXY protocol connection header.
1208
1209 This directive is solely for validating new PROXY protocol
1210 connections received from a port flagged with require-proxy-header.
1211 It is checked only once after TCP connection setup.
1212
1213 A deny match results in TCP connection closure.
1214
1215 An allow match is required for Squid to permit the corresponding
1216 TCP connection, before Squid even looks for HTTP request headers.
1217 If there is an allow match, Squid starts using PROXY header information
1218 to determine the source address of the connection for all future ACL
1219 checks, logging, etc.
1220
1221 SECURITY CONSIDERATIONS:
1222
1223 Any host from which we accept client IP details can place
1224 incorrect information in the relevant header, and Squid
1225 will use the incorrect information as if it were the
1226 source address of the request. This may enable remote
1227 hosts to bypass any access control restrictions that are
1228 based on the client's source addresses.
1229
1230 This clause only supports fast acl types.
1231 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1232DOC_END
1233
1234NAME: follow_x_forwarded_for
1235TYPE: acl_access
1236IFDEF: FOLLOW_X_FORWARDED_FOR
1237LOC: Config.accessList.followXFF
1238DEFAULT_IF_NONE: deny all
1239DEFAULT_DOC: X-Forwarded-For header will be ignored.
1240DOC_START
1241 Determine which client proxies can be trusted to provide correct
1242 information regarding real client IP address.
1243
1244 Requests may pass through a chain of several other proxies
1245 before reaching us. The original source details may by sent in:
1246 * HTTP message Forwarded header, or
1247 * HTTP message X-Forwarded-For header, or
1248 * PROXY protocol connection header.
1249
1250 PROXY protocol connections are controlled by the proxy_protocol_access
1251 directive which is checked before this.
1252
1253 If a request reaches us from a source that is allowed by this
1254 directive, then we trust the information it provides regarding
1255 the IP of the client it received from (if any).
1256
1257 For the purpose of ACLs used in this directive the src ACL type always
1258 matches the address we are testing and srcdomain matches its rDNS.
1259
1260 On each HTTP request Squid checks for X-Forwarded-For header fields.
1261 If found the header values are iterated in reverse order and an allow
1262 match is required for Squid to continue on to the next value.
1263 The verification ends when a value receives a deny match, cannot be
1264 tested, or there are no more values to test.
1265 NOTE: Squid does not yet follow the Forwarded HTTP header.
1266
1267 The end result of this process is an IP address that we will
1268 refer to as the indirect client address. This address may
1269 be treated as the client address for access control, ICAP, delay
1270 pools and logging, depending on the acl_uses_indirect_client,
1271 icap_uses_indirect_client, delay_pool_uses_indirect_client,
1272 log_uses_indirect_client and tproxy_uses_indirect_client options.
1273
1274 This clause only supports fast acl types.
1275 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1276
1277 SECURITY CONSIDERATIONS:
1278
1279 Any host from which we accept client IP details can place
1280 incorrect information in the relevant header, and Squid
1281 will use the incorrect information as if it were the
1282 source address of the request. This may enable remote
1283 hosts to bypass any access control restrictions that are
1284 based on the client's source addresses.
1285
1286 For example:
1287
1288 acl localhost src 127.0.0.1
1289 acl my_other_proxy srcdomain .proxy.example.com
1290 follow_x_forwarded_for allow localhost
1291 follow_x_forwarded_for allow my_other_proxy
1292DOC_END
1293
1294NAME: acl_uses_indirect_client
1295COMMENT: on|off
1296TYPE: onoff
1297IFDEF: FOLLOW_X_FORWARDED_FOR
1298DEFAULT: on
1299LOC: Config.onoff.acl_uses_indirect_client
1300DOC_START
1301 Controls whether the indirect client address
1302 (see follow_x_forwarded_for) is used instead of the
1303 direct client address in acl matching.
1304
1305 NOTE: maxconn ACL considers direct TCP links and indirect
1306 clients will always have zero. So no match.
1307DOC_END
1308
1309NAME: delay_pool_uses_indirect_client
1310COMMENT: on|off
1311TYPE: onoff
1312IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
1313DEFAULT: on
1314LOC: Config.onoff.delay_pool_uses_indirect_client
1315DOC_START
1316 Controls whether the indirect client address
1317 (see follow_x_forwarded_for) is used instead of the
1318 direct client address in delay pools.
1319DOC_END
1320
1321NAME: log_uses_indirect_client
1322COMMENT: on|off
1323TYPE: onoff
1324IFDEF: FOLLOW_X_FORWARDED_FOR
1325DEFAULT: on
1326LOC: Config.onoff.log_uses_indirect_client
1327DOC_START
1328 Controls whether the indirect client address
1329 (see follow_x_forwarded_for) is used instead of the
1330 direct client address in the access log.
1331DOC_END
1332
1333NAME: tproxy_uses_indirect_client
1334COMMENT: on|off
1335TYPE: onoff
1336IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
1337DEFAULT: off
1338LOC: Config.onoff.tproxy_uses_indirect_client
1339DOC_START
1340 Controls whether the indirect client address
1341 (see follow_x_forwarded_for) is used instead of the
1342 direct client address when spoofing the outgoing client.
1343
1344 This has no effect on requests arriving in non-tproxy
1345 mode ports.
1346
1347 SECURITY WARNING: Usage of this option is dangerous
1348 and should not be used trivially. Correct configuration
1349 of follow_x_forewarded_for with a limited set of trusted
1350 sources is required to prevent abuse of your proxy.
1351DOC_END
1352
1353NAME: spoof_client_ip
1354TYPE: acl_access
1355LOC: Config.accessList.spoof_client_ip
1356DEFAULT: none
1357DEFAULT_DOC: Allow spoofing on all TPROXY traffic.
1358DOC_START
1359 Control client IP address spoofing of TPROXY traffic based on
1360 defined access lists.
1361
1362 spoof_client_ip allow|deny [!]aclname ...
1363
1364 If there are no "spoof_client_ip" lines present, the default
1365 is to "allow" spoofing of any suitable request.
1366
1367 Note that the cache_peer "no-tproxy" option overrides this ACL.
1368
1369 This clause supports fast acl types.
1370 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1371DOC_END
1372
1373NAME: http_access
1374TYPE: acl_access
1375LOC: Config.accessList.http
1376DEFAULT_IF_NONE: deny all
1377DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1378DOC_START
1379 Allowing or Denying access based on defined access lists
1380
1381 To allow or deny a message received on an HTTP, HTTPS, or FTP port:
1382 http_access allow|deny [!]aclname ...
1383
1384 NOTE on default values:
1385
1386 If there are no "access" lines present, the default is to deny
1387 the request.
1388
1389 If none of the "access" lines cause a match, the default is the
1390 opposite of the last line in the list. If the last line was
1391 deny, the default is allow. Conversely, if the last line
1392 is allow, the default will be deny. For these reasons, it is a
1393 good idea to have an "deny all" entry at the end of your access
1394 lists to avoid potential confusion.
1395
1396 This clause supports both fast and slow acl types.
1397 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1398
1399NOCOMMENT_START
1400
1401#
1402# Recommended minimum Access Permission configuration:
1403#
1404# Deny requests to certain unsafe ports
1405http_access deny !Safe_ports
1406
1407# Deny CONNECT to other than secure SSL ports
1408http_access deny CONNECT !SSL_ports
1409
1410# Only allow cachemgr access from localhost
1411http_access allow localhost manager
1412http_access deny manager
1413
1414# We strongly recommend the following be uncommented to protect innocent
1415# web applications running on the proxy server who think the only
1416# one who can access services on "localhost" is a local user
1417#http_access deny to_localhost
1418
1419#
1420# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1421#
1422
1423# Example rule allowing access from your local networks.
1424# Adapt localnet in the ACL section to list your (internal) IP networks
1425# from where browsing should be allowed
1426http_access allow localnet
1427http_access allow localhost
1428
1429# And finally deny all other access to this proxy
1430http_access deny all
1431NOCOMMENT_END
1432DOC_END
1433
1434NAME: adapted_http_access http_access2
1435TYPE: acl_access
1436LOC: Config.accessList.adapted_http
1437DEFAULT: none
1438DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1439DOC_START
1440 Allowing or Denying access based on defined access lists
1441
1442 Essentially identical to http_access, but runs after redirectors
1443 and ICAP/eCAP adaptation. Allowing access control based on their
1444 output.
1445
1446 If not set then only http_access is used.
1447DOC_END
1448
1449NAME: http_reply_access
1450TYPE: acl_access
1451LOC: Config.accessList.reply
1452DEFAULT: none
1453DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1454DOC_START
1455 Allow replies to client requests. This is complementary to http_access.
1456
1457 http_reply_access allow|deny [!] aclname ...
1458
1459 NOTE: if there are no access lines present, the default is to allow
1460 all replies.
1461
1462 If none of the access lines cause a match the opposite of the
1463 last line will apply. Thus it is good practice to end the rules
1464 with an "allow all" or "deny all" entry.
1465
1466 This clause supports both fast and slow acl types.
1467 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1468DOC_END
1469
1470NAME: icp_access
1471TYPE: acl_access
1472LOC: Config.accessList.icp
1473DEFAULT: none
1474DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1475DOC_START
1476 Allowing or Denying access to the ICP port based on defined
1477 access lists
1478
1479 icp_access allow|deny [!]aclname ...
1480
1481 NOTE: The default if no icp_access lines are present is to
1482 deny all traffic. This default may cause problems with peers
1483 using ICP.
1484
1485 This clause only supports fast acl types.
1486 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1487
1488# Allow ICP queries from local networks only
1489#icp_access allow localnet
1490#icp_access deny all
1491DOC_END
1492
1493NAME: htcp_access
1494IFDEF: USE_HTCP
1495TYPE: acl_access
1496LOC: Config.accessList.htcp
1497DEFAULT: none
1498DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1499DOC_START
1500 Allowing or Denying access to the HTCP port based on defined
1501 access lists
1502
1503 htcp_access allow|deny [!]aclname ...
1504
1505 See also htcp_clr_access for details on access control for
1506 cache purge (CLR) HTCP messages.
1507
1508 NOTE: The default if no htcp_access lines are present is to
1509 deny all traffic. This default may cause problems with peers
1510 using the htcp option.
1511
1512 This clause only supports fast acl types.
1513 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1514
1515# Allow HTCP queries from local networks only
1516#htcp_access allow localnet
1517#htcp_access deny all
1518DOC_END
1519
1520NAME: htcp_clr_access
1521IFDEF: USE_HTCP
1522TYPE: acl_access
1523LOC: Config.accessList.htcp_clr
1524DEFAULT: none
1525DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1526DOC_START
1527 Allowing or Denying access to purge content using HTCP based
1528 on defined access lists.
1529 See htcp_access for details on general HTCP access control.
1530
1531 htcp_clr_access allow|deny [!]aclname ...
1532
1533 This clause only supports fast acl types.
1534 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1535
1536# Allow HTCP CLR requests from trusted peers
1537acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1538htcp_clr_access allow htcp_clr_peer
1539htcp_clr_access deny all
1540DOC_END
1541
1542NAME: miss_access
1543TYPE: acl_access
1544LOC: Config.accessList.miss
1545DEFAULT: none
1546DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1547DOC_START
1548 Determins whether network access is permitted when satisfying a request.
1549
1550 For example;
1551 to force your neighbors to use you as a sibling instead of
1552 a parent.
1553
1554 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1555 miss_access deny !localclients
1556 miss_access allow all
1557
1558 This means only your local clients are allowed to fetch relayed/MISS
1559 replies from the network and all other clients can only fetch cached
1560 objects (HITs).
1561
1562 The default for this setting allows all clients who passed the
1563 http_access rules to relay via this proxy.
1564
1565 This clause only supports fast acl types.
1566 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1567DOC_END
1568
1569NAME: ident_lookup_access
1570TYPE: acl_access
1571IFDEF: USE_IDENT
1572DEFAULT: none
1573DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
1574LOC: Ident::TheConfig.identLookup
1575DOC_START
1576 A list of ACL elements which, if matched, cause an ident
1577 (RFC 931) lookup to be performed for this request. For
1578 example, you might choose to always perform ident lookups
1579 for your main multi-user Unix boxes, but not for your Macs
1580 and PCs. By default, ident lookups are not performed for
1581 any requests.
1582
1583 To enable ident lookups for specific client addresses, you
1584 can follow this example:
1585
1586 acl ident_aware_hosts src 198.168.1.0/24
1587 ident_lookup_access allow ident_aware_hosts
1588 ident_lookup_access deny all
1589
1590 Only src type ACL checks are fully supported. A srcdomain
1591 ACL might work at times, but it will not always provide
1592 the correct result.
1593
1594 This clause only supports fast acl types.
1595 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1596DOC_END
1597
1598NAME: reply_body_max_size
1599COMMENT: size [acl acl...]
1600TYPE: acl_b_size_t
1601DEFAULT: none
1602DEFAULT_DOC: No limit is applied.
1603LOC: Config.ReplyBodySize
1604DOC_START
1605 This option specifies the maximum size of a reply body. It can be
1606 used to prevent users from downloading very large files, such as
1607 MP3's and movies. When the reply headers are received, the
1608 reply_body_max_size lines are processed, and the first line where
1609 all (if any) listed ACLs are true is used as the maximum body size
1610 for this reply.
1611
1612 This size is checked twice. First when we get the reply headers,
1613 we check the content-length value. If the content length value exists
1614 and is larger than the allowed size, the request is denied and the
1615 user receives an error message that says "the request or reply
1616 is too large." If there is no content-length, and the reply
1617 size exceeds this limit, the client's connection is just closed
1618 and they will receive a partial reply.
1619
1620 WARNING: downstream caches probably can not detect a partial reply
1621 if there is no content-length header, so they will cache
1622 partial responses and give them out as hits. You should NOT
1623 use this option if you have downstream caches.
1624
1625 WARNING: A maximum size smaller than the size of squid's error messages
1626 will cause an infinite loop and crash squid. Ensure that the smallest
1627 non-zero value you use is greater that the maximum header size plus
1628 the size of your largest error page.
1629
1630 If you set this parameter none (the default), there will be
1631 no limit imposed.
1632
1633 Configuration Format is:
1634 reply_body_max_size SIZE UNITS [acl ...]
1635 ie.
1636 reply_body_max_size 10 MB
1637
1638DOC_END
1639
1640COMMENT_START
1641 NETWORK OPTIONS
1642 -----------------------------------------------------------------------------
1643COMMENT_END
1644
1645NAME: http_port ascii_port
1646TYPE: PortCfg
1647DEFAULT: none
1648LOC: HttpPortList
1649DOC_START
1650 Usage: port [mode] [options]
1651 hostname:port [mode] [options]
1652 1.2.3.4:port [mode] [options]
1653
1654 The socket addresses where Squid will listen for HTTP client
1655 requests. You may specify multiple socket addresses.
1656 There are three forms: port alone, hostname with port, and
1657 IP address with port. If you specify a hostname or IP
1658 address, Squid binds the socket to that specific
1659 address. Most likely, you do not need to bind to a specific
1660 address, so you can use the port number alone.
1661
1662 If you are running Squid in accelerator mode, you
1663 probably want to listen on port 80 also, or instead.
1664
1665 The -a command line option may be used to specify additional
1666 port(s) where Squid listens for proxy request. Such ports will
1667 be plain proxy ports with no options.
1668
1669 You may specify multiple socket addresses on multiple lines.
1670
1671 Modes:
1672
1673 intercept Support for IP-Layer interception of
1674 outgoing requests without browser settings.
1675 NP: disables authentication and IPv6 on the port.
1676
1677 tproxy Support Linux TPROXY for spoofing outgoing
1678 connections using the client IP address.
1679 NP: disables authentication and maybe IPv6 on the port.
1680
1681 accel Accelerator / reverse proxy mode
1682
1683 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1684 establish secure connection with the client and with
1685 the server, decrypt HTTPS messages as they pass through
1686 Squid, and treat them as unencrypted HTTP messages,
1687 becoming the man-in-the-middle.
1688
1689 The ssl_bump option is required to fully enable
1690 bumping of CONNECT requests.
1691
1692 Omitting the mode flag causes default forward proxy mode to be used.
1693
1694
1695 Accelerator Mode Options:
1696
1697 defaultsite=domainname
1698 What to use for the Host: header if it is not present
1699 in a request. Determines what site (not origin server)
1700 accelerators should consider the default.
1701
1702 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1703
1704 protocol= Protocol to reconstruct accelerated and intercepted
1705 requests with. Defaults to HTTP/1.1 for http_port and
1706 HTTPS/1.1 for https_port.
1707 When an unsupported value is configured Squid will
1708 produce a FATAL error.
1709 Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
1710
1711 vport Virtual host port support. Using the http_port number
1712 instead of the port passed on Host: headers.
1713
1714 vport=NN Virtual host port support. Using the specified port
1715 number instead of the port passed on Host: headers.
1716
1717 act-as-origin
1718 Act as if this Squid is the origin server.
1719 This currently means generate new Date: and Expires:
1720 headers on HIT instead of adding Age:.
1721
1722 ignore-cc Ignore request Cache-Control headers.
1723
1724 WARNING: This option violates HTTP specifications if
1725 used in non-accelerator setups.
1726
1727 allow-direct Allow direct forwarding in accelerator mode. Normally
1728 accelerated requests are denied direct forwarding as if
1729 never_direct was used.
1730
1731 WARNING: this option opens accelerator mode to security
1732 vulnerabilities usually only affecting in interception
1733 mode. Make sure to protect forwarding with suitable
1734 http_access rules when using this.
1735
1736
1737 SSL Bump Mode Options:
1738 In addition to these options ssl-bump requires TLS/SSL options.
1739
1740 generate-host-certificates[=<on|off>]
1741 Dynamically create SSL server certificates for the
1742 destination hosts of bumped CONNECT requests.When
1743 enabled, the cert and key options are used to sign
1744 generated certificates. Otherwise generated
1745 certificate will be selfsigned.
1746 If there is a CA certificate lifetime of the generated
1747 certificate equals lifetime of the CA certificate. If
1748 generated certificate is selfsigned lifetime is three
1749 years.
1750 This option is enabled by default when ssl-bump is used.
1751 See the ssl-bump option above for more information.
1752
1753 dynamic_cert_mem_cache_size=SIZE
1754 Approximate total RAM size spent on cached generated
1755 certificates. If set to zero, caching is disabled. The
1756 default value is 4MB.
1757
1758 TLS / SSL Options:
1759
1760 cert= Path to SSL certificate (PEM format).
1761
1762 key= Path to SSL private key file (PEM format)
1763 if not specified, the certificate file is
1764 assumed to be a combined certificate and
1765 key file.
1766
1767 version= The version of SSL/TLS supported
1768 1 automatic (default)
1769 3 SSLv3 only
1770 4 TLSv1.0 only
1771 5 TLSv1.1 only
1772 6 TLSv1.2 only
1773
1774 cipher= Colon separated list of supported ciphers.
1775 NOTE: some ciphers such as EDH ciphers depend on
1776 additional settings. If those settings are
1777 omitted the ciphers may be silently ignored
1778 by the OpenSSL library.
1779
1780 options= Various SSL implementation options. The most important
1781 being:
1782 NO_SSLv3 Disallow the use of SSLv3
1783 NO_TLSv1 Disallow the use of TLSv1.0
1784 NO_TLSv1_1 Disallow the use of TLSv1.1
1785 NO_TLSv1_2 Disallow the use of TLSv1.2
1786 SINGLE_DH_USE Always create a new key when using
1787 temporary/ephemeral DH key exchanges
1788 ALL Enable various bug workarounds
1789 suggested as "harmless" by OpenSSL
1790 Be warned that this reduces SSL/TLS
1791 strength to some attacks.
1792 See OpenSSL SSL_CTX_set_options documentation for a
1793 complete list of options.
1794
1795 clientca= File containing the list of CAs to use when
1796 requesting a client certificate.
1797
1798 cafile= File containing additional CA certificates to
1799 use when verifying client certificates. If unset
1800 clientca will be used.
1801
1802 capath= Directory containing additional CA certificates
1803 and CRL lists to use when verifying client certificates.
1804
1805 crlfile= File of additional CRL lists to use when verifying
1806 the client certificate, in addition to CRLs stored in
1807 the capath. Implies VERIFY_CRL flag below.
1808
1809 dhparams= File containing DH parameters for temporary/ephemeral
1810 DH key exchanges. See OpenSSL documentation for details
1811 on how to create this file.
1812 WARNING: EDH ciphers will be silently disabled if this
1813 option is not set.
1814
1815 sslflags= Various flags modifying the use of SSL:
1816 DELAYED_AUTH
1817 Don't request client certificates
1818 immediately, but wait until acl processing
1819 requires a certificate (not yet implemented).
1820 NO_DEFAULT_CA
1821 Don't use the default CA lists built in
1822 to OpenSSL.
1823 NO_SESSION_REUSE
1824 Don't allow for session reuse. Each connection
1825 will result in a new SSL session.
1826 VERIFY_CRL
1827 Verify CRL lists when accepting client
1828 certificates.
1829 VERIFY_CRL_ALL
1830 Verify CRL lists for all certificates in the
1831 client certificate chain.
1832
1833 sslcontext= SSL session ID context identifier.
1834
1835 Other Options:
1836
1837 connection-auth[=on|off]
1838 use connection-auth=off to tell Squid to prevent
1839 forwarding Microsoft connection oriented authentication
1840 (NTLM, Negotiate and Kerberos)
1841
1842 disable-pmtu-discovery=
1843 Control Path-MTU discovery usage:
1844 off lets OS decide on what to do (default).
1845 transparent disable PMTU discovery when transparent
1846 support is enabled.
1847 always disable always PMTU discovery.
1848
1849 In many setups of transparently intercepting proxies
1850 Path-MTU discovery can not work on traffic towards the
1851 clients. This is the case when the intercepting device
1852 does not fully track connections and fails to forward
1853 ICMP must fragment messages to the cache server. If you
1854 have such setup and experience that certain clients
1855 sporadically hang or never complete requests set
1856 disable-pmtu-discovery option to 'transparent'.
1857
1858 name= Specifies a internal name for the port. Defaults to
1859 the port specification (port or addr:port)
1860
1861 tcpkeepalive[=idle,interval,timeout]
1862 Enable TCP keepalive probes of idle connections.
1863 In seconds; idle is the initial time before TCP starts
1864 probing the connection, interval how often to probe, and
1865 timeout the time before giving up.
1866
1867 require-proxy-header
1868 Require PROXY protocol version 1 or 2 connections.
1869 The proxy_protocol_access is required to whitelist
1870 downstream proxies which can be trusted.
1871
1872 If you run Squid on a dual-homed machine with an internal
1873 and an external interface we recommend you to specify the
1874 internal address:port in http_port. This way Squid will only be
1875 visible on the internal address.
1876
1877NOCOMMENT_START
1878
1879# Squid normally listens to port 3128
1880http_port @DEFAULT_HTTP_PORT@
1881NOCOMMENT_END
1882DOC_END
1883
1884NAME: https_port
1885IFDEF: USE_OPENSSL
1886TYPE: PortCfg
1887DEFAULT: none
1888LOC: HttpsPortList
1889DOC_START
1890 Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1891
1892 The socket address where Squid will listen for client requests made
1893 over TLS or SSL connections. Commonly referred to as HTTPS.
1894
1895 This is most useful for situations where you are running squid in
1896 accelerator mode and you want to do the SSL work at the accelerator level.
1897
1898 You may specify multiple socket addresses on multiple lines,
1899 each with their own SSL certificate and/or options.
1900
1901 Modes:
1902
1903 accel Accelerator / reverse proxy mode
1904
1905 intercept Support for IP-Layer interception of
1906 outgoing requests without browser settings.
1907 NP: disables authentication and IPv6 on the port.
1908
1909 tproxy Support Linux TPROXY for spoofing outgoing
1910 connections using the client IP address.
1911 NP: disables authentication and maybe IPv6 on the port.
1912
1913 ssl-bump For each intercepted connection allowed by ssl_bump
1914 ACLs, establish a secure connection with the client and with
1915 the server, decrypt HTTPS messages as they pass through
1916 Squid, and treat them as unencrypted HTTP messages,
1917 becoming the man-in-the-middle.
1918
1919 An "ssl_bump server-first" match is required to
1920 fully enable bumping of intercepted SSL connections.
1921
1922 Requires tproxy or intercept.
1923
1924 Omitting the mode flag causes default forward proxy mode to be used.
1925
1926
1927 See http_port for a list of generic options
1928
1929
1930 SSL Options:
1931
1932 cert= Path to SSL certificate (PEM format).
1933
1934 key= Path to SSL private key file (PEM format)
1935 if not specified, the certificate file is
1936 assumed to be a combined certificate and
1937 key file.
1938
1939 version= The version of SSL/TLS supported
1940 1 automatic (default)
1941 3 SSLv3 only
1942 4 TLSv1 only
1943
1944 cipher= Colon separated list of supported ciphers.
1945
1946 options= Various SSL engine options. The most important
1947 being:
1948 NO_SSLv3 Disallow the use of SSLv3
1949 NO_TLSv1 Disallow the use of TLSv1
1950 SINGLE_DH_USE Always create a new key when using
1951 temporary/ephemeral DH key exchanges
1952 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1953 documentation for a complete list of options.
1954
1955 clientca= File containing the list of CAs to use when
1956 requesting a client certificate.
1957
1958 cafile= File containing additional CA certificates to
1959 use when verifying client certificates. If unset
1960 clientca will be used.
1961
1962 capath= Directory containing additional CA certificates
1963 and CRL lists to use when verifying client certificates.
1964
1965 crlfile= File of additional CRL lists to use when verifying
1966 the client certificate, in addition to CRLs stored in
1967 the capath. Implies VERIFY_CRL flag below.
1968
1969 dhparams= File containing DH parameters for temporary/ephemeral
1970 DH key exchanges.
1971
1972 sslflags= Various flags modifying the use of SSL:
1973 DELAYED_AUTH
1974 Don't request client certificates
1975 immediately, but wait until acl processing
1976 requires a certificate (not yet implemented).
1977 NO_DEFAULT_CA
1978 Don't use the default CA lists built in
1979 to OpenSSL.
1980 NO_SESSION_REUSE
1981 Don't allow for session reuse. Each connection
1982 will result in a new SSL session.
1983 VERIFY_CRL
1984 Verify CRL lists when accepting client
1985 certificates.
1986 VERIFY_CRL_ALL
1987 Verify CRL lists for all certificates in the
1988 client certificate chain.
1989
1990 sslcontext= SSL session ID context identifier.
1991
1992 generate-host-certificates[=<on|off>]
1993 Dynamically create SSL server certificates for the
1994 destination hosts of bumped SSL requests.When
1995 enabled, the cert and key options are used to sign
1996 generated certificates. Otherwise generated
1997 certificate will be selfsigned.
1998 If there is CA certificate life time of generated
1999 certificate equals lifetime of CA certificate. If
2000 generated certificate is selfsigned lifetime is three
2001 years.
2002 This option is enabled by default when SslBump is used.
2003 See the sslBump option above for more information.
2004
2005 dynamic_cert_mem_cache_size=SIZE
2006 Approximate total RAM size spent on cached generated
2007 certificates. If set to zero, caching is disabled. The
2008 default value is 4MB.
2009
2010 See http_port for a list of available options.
2011DOC_END
2012
2013NAME: ftp_port
2014TYPE: PortCfg
2015DEFAULT: none
2016LOC: FtpPortList
2017DOC_START
2018 Enables Native FTP proxy by specifying the socket address where Squid
2019 listens for FTP client requests. See http_port directive for various
2020 ways to specify the listening address and mode.
2021
2022 Usage: ftp_port address [mode] [options]
2023
2024 WARNING: This is a new, experimental, complex feature that has seen
2025 limited production exposure. Some Squid modules (e.g., caching) do not
2026 currently work with native FTP proxying, and many features have not
2027 even been tested for compatibility. Test well before deploying!
2028
2029 Native FTP proxying differs substantially from proxying HTTP requests
2030 with ftp:// URIs because Squid works as an FTP server and receives
2031 actual FTP commands (rather than HTTP requests with FTP URLs).
2032
2033 Native FTP commands accepted at ftp_port are internally converted or
2034 wrapped into HTTP-like messages. The same happens to Native FTP
2035 responses received from FTP origin servers. Those HTTP-like messages
2036 are shoveled through regular access control and adaptation layers
2037 between the FTP client and the FTP origin server. This allows Squid to
2038 examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
2039 mechanisms when shoveling wrapped FTP messages. For example,
2040 http_access and adaptation_access directives are used.
2041
2042 Modes:
2043
2044 intercept Same as http_port intercept. The FTP origin address is
2045 determined based on the intended destination of the
2046 intercepted connection.
2047
2048 tproxy Support Linux TPROXY for spoofing outgoing
2049 connections using the client IP address.
2050 NP: disables authentication and maybe IPv6 on the port.
2051
2052 By default (i.e., without an explicit mode option), Squid extracts the
2053 FTP origin address from the login@origin parameter of the FTP USER
2054 command. Many popular FTP clients support such native FTP proxying.
2055
2056 Options:
2057
2058 name=token Specifies an internal name for the port. Defaults to
2059 the port address. Usable with myportname ACL.
2060
2061 ftp-track-dirs
2062 Enables tracking of FTP directories by injecting extra
2063 PWD commands and adjusting Request-URI (in wrapping
2064 HTTP requests) to reflect the current FTP server
2065 directory. Tracking is disabled by default.
2066
2067 protocol=FTP Protocol to reconstruct accelerated and intercepted
2068 requests with. Defaults to FTP. No other accepted
2069 values have been tested with. An unsupported value
2070 results in a FATAL error. Accepted values are FTP,
2071 HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
2072
2073 Other http_port modes and options that are not specific to HTTP and
2074 HTTPS may also work.
2075DOC_END
2076
2077NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2078TYPE: acl_tos
2079DEFAULT: none
2080LOC: Ip::Qos::TheConfig.tosToServer
2081DOC_START
2082 Allows you to select a TOS/Diffserv value for packets outgoing
2083 on the server side, based on an ACL.
2084
2085 tcp_outgoing_tos ds-field [!]aclname ...
2086
2087 Example where normal_service_net uses the TOS value 0x00
2088 and good_service_net uses 0x20
2089
2090 acl normal_service_net src 10.0.0.0/24
2091 acl good_service_net src 10.0.1.0/24
2092 tcp_outgoing_tos 0x00 normal_service_net
2093 tcp_outgoing_tos 0x20 good_service_net
2094
2095 TOS/DSCP values really only have local significance - so you should
2096 know what you're specifying. For more information, see RFC2474,
2097 RFC2475, and RFC3260.
2098
2099 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2100 "default" to use whatever default your host has. Note that in
2101 practice often only multiples of 4 is usable as the two rightmost bits
2102 have been redefined for use by ECN (RFC 3168 section 23.1).
2103
2104 Processing proceeds in the order specified, and stops at first fully
2105 matching line.
2106
2107 Only fast ACLs are supported.
2108DOC_END
2109
2110NAME: clientside_tos
2111TYPE: acl_tos
2112DEFAULT: none
2113LOC: Ip::Qos::TheConfig.tosToClient
2114DOC_START
2115 Allows you to select a TOS/Diffserv value for packets being transmitted
2116 on the client-side, based on an ACL.
2117
2118 clientside_tos ds-field [!]aclname ...
2119
2120 Example where normal_service_net uses the TOS value 0x00
2121 and good_service_net uses 0x20
2122
2123 acl normal_service_net src 10.0.0.0/24
2124 acl good_service_net src 10.0.1.0/24
2125 clientside_tos 0x00 normal_service_net
2126 clientside_tos 0x20 good_service_net
2127
2128 Note: This feature is incompatible with qos_flows. Any TOS values set here
2129 will be overwritten by TOS values in qos_flows.
2130DOC_END
2131
2132NAME: tcp_outgoing_mark
2133TYPE: acl_nfmark
2134IFDEF: SO_MARK&&USE_LIBCAP
2135DEFAULT: none
2136LOC: Ip::Qos::TheConfig.nfmarkToServer
2137DOC_START
2138 Allows you to apply a Netfilter mark value to outgoing packets
2139 on the server side, based on an ACL.
2140
2141 tcp_outgoing_mark mark-value [!]aclname ...
2142
2143 Example where normal_service_net uses the mark value 0x00
2144 and good_service_net uses 0x20
2145
2146 acl normal_service_net src 10.0.0.0/24
2147 acl good_service_net src 10.0.1.0/24
2148 tcp_outgoing_mark 0x00 normal_service_net
2149 tcp_outgoing_mark 0x20 good_service_net
2150
2151 Only fast ACLs are supported.
2152DOC_END
2153
2154NAME: clientside_mark
2155TYPE: acl_nfmark
2156IFDEF: SO_MARK&&USE_LIBCAP
2157DEFAULT: none
2158LOC: Ip::Qos::TheConfig.nfmarkToClient
2159DOC_START
2160 Allows you to apply a Netfilter mark value to packets being transmitted
2161 on the client-side, based on an ACL.
2162
2163 clientside_mark mark-value [!]aclname ...
2164
2165 Example where normal_service_net uses the mark value 0x00
2166 and good_service_net uses 0x20
2167
2168 acl normal_service_net src 10.0.0.0/24
2169 acl good_service_net src 10.0.1.0/24
2170 clientside_mark 0x00 normal_service_net
2171 clientside_mark 0x20 good_service_net
2172
2173 Note: This feature is incompatible with qos_flows. Any mark values set here
2174 will be overwritten by mark values in qos_flows.
2175DOC_END
2176
2177NAME: qos_flows
2178TYPE: QosConfig
2179IFDEF: USE_QOS_TOS
2180DEFAULT: none
2181LOC: Ip::Qos::TheConfig
2182DOC_START
2183 Allows you to select a TOS/DSCP value to mark outgoing
2184 connections to the client, based on where the reply was sourced.
2185 For platforms using netfilter, allows you to set a netfilter mark
2186 value instead of, or in addition to, a TOS value.
2187
2188 By default this functionality is disabled. To enable it with the default
2189 settings simply use "qos_flows mark" or "qos_flows tos". Default
2190 settings will result in the netfilter mark or TOS value being copied
2191 from the upstream connection to the client. Note that it is the connection
2192 CONNMARK value not the packet MARK value that is copied.
2193
2194 It is not currently possible to copy the mark or TOS value from the
2195 client to the upstream connection request.
2196
2197 TOS values really only have local significance - so you should
2198 know what you're specifying. For more information, see RFC2474,
2199 RFC2475, and RFC3260.
2200
2201 The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
2202 in practice often only multiples of 4 is usable as the two rightmost bits
2203 have been redefined for use by ECN (RFC 3168 section 23.1).
2204
2205 Mark values can be any unsigned 32-bit integer value.
2206
2207 This setting is configured by setting the following values:
2208
2209 tos|mark Whether to set TOS or netfilter mark values
2210
2211 local-hit=0xFF Value to mark local cache hits.
2212
2213 sibling-hit=0xFF Value to mark hits from sibling peers.
2214
2215 parent-hit=0xFF Value to mark hits from parent peers.
2216
2217 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2218 over the preserve-miss feature (see below), unless
2219 mask is specified, in which case only the bits
2220 specified in the mask are written.
2221
2222 The TOS variant of the following features are only possible on Linux
2223 and require your kernel to be patched with the TOS preserving ZPH
2224 patch, available from http://zph.bratcheda.org
2225 No patch is needed to preserve the netfilter mark, which will work
2226 with all variants of netfilter.
2227
2228 disable-preserve-miss
2229 This option disables the preservation of the TOS or netfilter
2230 mark. By default, the existing TOS or netfilter mark value of
2231 the response coming from the remote server will be retained
2232 and masked with miss-mark.
2233 NOTE: in the case of a netfilter mark, the mark must be set on
2234 the connection (using the CONNMARK target) not on the packet
2235 (MARK target).
2236
2237 miss-mask=0xFF
2238 Allows you to mask certain bits in the TOS or mark value
2239 received from the remote server, before copying the value to
2240 the TOS sent towards clients.
2241 Default for tos: 0xFF (TOS from server is not changed).
2242 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2243
2244 All of these features require the --enable-zph-qos compilation flag
2245 (enabled by default). Netfilter marking also requires the
2246 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2247 libcap 2.09+ (--with-libcap).
2248
2249DOC_END
2250
2251NAME: tcp_outgoing_address
2252TYPE: acl_address
2253DEFAULT: none
2254DEFAULT_DOC: Address selection is performed by the operating system.
2255LOC: Config.accessList.outgoing_address
2256DOC_START
2257 Allows you to map requests to different outgoing IP addresses
2258 based on the username or source address of the user making
2259 the request.
2260
2261 tcp_outgoing_address ipaddr [[!]aclname] ...
2262
2263 For example;
2264 Forwarding clients with dedicated IPs for certain subnets.
2265
2266 acl normal_service_net src 10.0.0.0/24
2267 acl good_service_net src 10.0.2.0/24
2268
2269 tcp_outgoing_address 2001:db8::c001 good_service_net
2270 tcp_outgoing_address 10.1.0.2 good_service_net
2271
2272 tcp_outgoing_address 2001:db8::beef normal_service_net
2273 tcp_outgoing_address 10.1.0.1 normal_service_net
2274
2275 tcp_outgoing_address 2001:db8::1
2276 tcp_outgoing_address 10.1.0.3
2277
2278 Processing proceeds in the order specified, and stops at first fully
2279 matching line.
2280
2281 Squid will add an implicit IP version test to each line.
2282 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2283 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2284
2285
2286 NOTE: The use of this directive using client dependent ACLs is
2287 incompatible with the use of server side persistent connections. To
2288 ensure correct results it is best to set server_persistent_connections
2289 to off when using this directive in such configurations.
2290
2291 NOTE: The use of this directive to set a local IP on outgoing TCP links
2292 is incompatible with using TPROXY to set client IP out outbound TCP links.
2293 When needing to contact peers use the no-tproxy cache_peer option and the
2294 client_dst_passthru directive re-enable normal forwarding such as this.
2295
2296DOC_END
2297
2298NAME: host_verify_strict
2299TYPE: onoff
2300DEFAULT: off
2301LOC: Config.onoff.hostStrictVerify
2302DOC_START
2303 Regardless of this option setting, when dealing with intercepted
2304 traffic, Squid always verifies that the destination IP address matches
2305 the Host header domain or IP (called 'authority form URL').
2306
2307 This enforcement is performed to satisfy a MUST-level requirement in
2308 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2309 authority of the origin server or gateway given by the original URL".
2310
2311 When set to ON:
2312 Squid always responds with an HTTP 409 (Conflict) error
2313 page and logs a security warning if there is no match.
2314
2315 Squid verifies that the destination IP address matches
2316 the Host header for forward-proxy and reverse-proxy traffic
2317 as well. For those traffic types, Squid also enables the
2318 following checks, comparing the corresponding Host header
2319 and Request-URI components:
2320
2321 * The host names (domain or IP) must be identical,
2322 but valueless or missing Host header disables all checks.
2323 For the two host names to match, both must be either IP
2324 or FQDN.
2325
2326 * Port numbers must be identical, but if a port is missing
2327 the scheme-default port is assumed.
2328
2329
2330 When set to OFF (the default):
2331 Squid allows suspicious requests to continue but logs a
2332 security warning and blocks caching of the response.
2333
2334 * Forward-proxy traffic is not checked at all.
2335
2336 * Reverse-proxy traffic is not checked at all.
2337
2338 * Intercepted traffic which passes verification is handled
2339 according to client_dst_passthru.
2340
2341 * Intercepted requests which fail verification are sent
2342 to the client original destination instead of DIRECT.
2343 This overrides 'client_dst_passthru off'.
2344
2345 For now suspicious intercepted CONNECT requests are always
2346 responded to with an HTTP 409 (Conflict) error page.
2347
2348
2349 SECURITY NOTE:
2350
2351 As described in CVE-2009-0801 when the Host: header alone is used
2352 to determine the destination of a request it becomes trivial for
2353 malicious scripts on remote websites to bypass browser same-origin
2354 security policy and sandboxing protections.
2355
2356 The cause of this is that such applets are allowed to perform their
2357 own HTTP stack, in which case the same-origin policy of the browser
2358 sandbox only verifies that the applet tries to contact the same IP
2359 as from where it was loaded at the IP level. The Host: header may
2360 be different from the connected IP and approved origin.
2361
2362DOC_END
2363
2364NAME: client_dst_passthru
2365TYPE: onoff
2366DEFAULT: on
2367LOC: Config.onoff.client_dst_passthru
2368DOC_START
2369 With NAT or TPROXY intercepted traffic Squid may pass the request
2370 directly to the original client destination IP or seek a faster
2371 source using the HTTP Host header.
2372
2373 Using Host to locate alternative servers can provide faster
2374 connectivity with a range of failure recovery options.
2375 But can also lead to connectivity trouble when the client and
2376 server are attempting stateful interactions unaware of the proxy.
2377
2378 This option (on by default) prevents alternative DNS entries being
2379 located to send intercepted traffic DIRECT to an origin server.
2380 The clients original destination IP and port will be used instead.
2381
2382 Regardless of this option setting, when dealing with intercepted
2383 traffic Squid will verify the Host: header and any traffic which
2384 fails Host verification will be treated as if this option were ON.
2385
2386 see host_verify_strict for details on the verification process.
2387DOC_END
2388
2389COMMENT_START
2390 SSL OPTIONS
2391 -----------------------------------------------------------------------------
2392COMMENT_END
2393
2394NAME: ssl_unclean_shutdown
2395IFDEF: USE_OPENSSL
2396TYPE: onoff
2397DEFAULT: off
2398LOC: Config.SSL.unclean_shutdown
2399DOC_START
2400 Some browsers (especially MSIE) bugs out on SSL shutdown
2401 messages.
2402DOC_END
2403
2404NAME: ssl_engine
2405IFDEF: USE_OPENSSL
2406TYPE: string
2407LOC: Config.SSL.ssl_engine
2408DEFAULT: none
2409DOC_START
2410 The OpenSSL engine to use. You will need to set this if you
2411 would like to use hardware SSL acceleration for example.
2412DOC_END
2413
2414NAME: sslproxy_client_certificate
2415IFDEF: USE_OPENSSL
2416DEFAULT: none
2417LOC: Config.ssl_client.cert
2418TYPE: string
2419DOC_START
2420 Client SSL Certificate to use when proxying https:// URLs
2421DOC_END
2422
2423NAME: sslproxy_client_key
2424IFDEF: USE_OPENSSL
2425DEFAULT: none
2426LOC: Config.ssl_client.key
2427TYPE: string
2428DOC_START
2429 Client SSL Key to use when proxying https:// URLs
2430DOC_END
2431
2432NAME: sslproxy_version
2433IFDEF: USE_OPENSSL
2434DEFAULT: 1
2435DEFAULT_DOC: automatic SSL/TLS version negotiation
2436LOC: Config.ssl_client.version
2437TYPE: int
2438DOC_START
2439 SSL version level to use when proxying https:// URLs
2440
2441 The versions of SSL/TLS supported:
2442
2443 1 automatic (default)
2444 3 SSLv3 only
2445 4 TLSv1.0 only
2446 5 TLSv1.1 only
2447 6 TLSv1.2 only
2448DOC_END
2449
2450NAME: sslproxy_options
2451IFDEF: USE_OPENSSL
2452DEFAULT: none
2453LOC: Config.ssl_client.options
2454TYPE: string
2455DOC_START
2456 SSL implementation options to use when proxying https:// URLs
2457
2458 The most important being:
2459
2460 NO_SSLv3 Disallow the use of SSLv3
2461 NO_TLSv1 Disallow the use of TLSv1.0
2462 NO_TLSv1_1 Disallow the use of TLSv1.1
2463 NO_TLSv1_2 Disallow the use of TLSv1.2
2464 SINGLE_DH_USE
2465 Always create a new key when using temporary/ephemeral
2466 DH key exchanges
2467 SSL_OP_NO_TICKET
2468 Disable use of RFC5077 session tickets. Some servers
2469 may have problems understanding the TLS extension due
2470 to ambiguous specification in RFC4507.
2471 ALL Enable various bug workarounds suggested as "harmless"
2472 by OpenSSL. Be warned that this may reduce SSL/TLS
2473 strength to some attacks.
2474
2475 See the OpenSSL SSL_CTX_set_options documentation for a
2476 complete list of possible options.
2477DOC_END
2478
2479NAME: sslproxy_cipher
2480IFDEF: USE_OPENSSL
2481DEFAULT: none
2482LOC: Config.ssl_client.cipher
2483TYPE: string
2484DOC_START
2485 SSL cipher list to use when proxying https:// URLs
2486
2487 Colon separated list of supported ciphers.
2488DOC_END
2489
2490NAME: sslproxy_cafile
2491IFDEF: USE_OPENSSL
2492DEFAULT: none
2493LOC: Config.ssl_client.cafile
2494TYPE: string
2495DOC_START
2496 file containing CA certificates to use when verifying server
2497 certificates while proxying https:// URLs
2498DOC_END
2499
2500NAME: sslproxy_capath
2501IFDEF: USE_OPENSSL
2502DEFAULT: none
2503LOC: Config.ssl_client.capath
2504TYPE: string
2505DOC_START
2506 directory containing CA certificates to use when verifying
2507 server certificates while proxying https:// URLs
2508DOC_END
2509
2510NAME: sslproxy_session_ttl
2511IFDEF: USE_OPENSSL
2512DEFAULT: 300
2513LOC: Config.SSL.session_ttl
2514TYPE: int
2515DOC_START
2516 Sets the timeout value for SSL sessions
2517DOC_END
2518
2519NAME: sslproxy_session_cache_size
2520IFDEF: USE_OPENSSL
2521DEFAULT: 2 MB
2522LOC: Config.SSL.sessionCacheSize
2523TYPE: b_size_t
2524DOC_START
2525 Sets the cache size to use for ssl session
2526DOC_END
2527
2528NAME: sslproxy_cert_sign_hash
2529IFDEF: USE_OPENSSL
2530DEFAULT: none
2531LOC: Config.SSL.certSignHash
2532TYPE: string
2533DOC_START
2534 Sets the hashing algorithm to use when signing generated certificates.
2535 Valid algorithm names depend on the OpenSSL library used. The following
2536 names are usually available: sha1, sha256, sha512, and md5. Please see
2537 your OpenSSL library manual for the available hashes. By default, Squids
2538 that support this option use sha256 hashes.
2539
2540 Squid does not forcefully purge cached certificates that were generated
2541 with an algorithm other than the currently configured one. They remain
2542 in the cache, subject to the regular cache eviction policy, and become
2543 useful if the algorithm changes again.
2544DOC_END
2545
2546NAME: ssl_bump
2547IFDEF: USE_OPENSSL
2548TYPE: sslproxy_ssl_bump
2549LOC: Config.accessList.ssl_bump
2550DEFAULT_DOC: Become a TCP tunnel without decrypting proxied traffic.
2551DEFAULT: none
2552DOC_START
2553 This option is consulted when a CONNECT request is received on
2554 an http_port (or a new connection is intercepted at an
2555 https_port), provided that port was configured with an ssl-bump
2556 flag. The subsequent data on the connection is either treated as
2557 HTTPS and decrypted OR tunneled at TCP level without decryption,
2558 depending on the first matching bumping "action".
2559
2560 ssl_bump <action> [!]acl ...
2561
2562 The following bumping actions are currently supported:
2563
2564 splice
2565 Become a TCP tunnel without decrypting proxied traffic.
2566 This is the default action.
2567
2568 bump
2569 Establish a secure connection with the server and, using a
2570 mimicked server certificate, with the client.
2571
2572 peek
2573 Receive client (step SslBump1) or server (step SslBump2)
2574 certificate while preserving the possibility of splicing the
2575 connection. Peeking at the server certificate (during step 2)
2576 usually precludes bumping of the connection at step 3.
2577
2578 stare
2579 Receive client (step SslBump1) or server (step SslBump2)
2580 certificate while preserving the possibility of bumping the
2581 connection. Staring at the server certificate (during step 2)
2582 usually precludes splicing of the connection at step 3.
2583
2584 terminate
2585 Close client and server connections.
2586
2587 Backward compatibility actions available at step SslBump1:
2588
2589 client-first
2590 Bump the connection. Establish a secure connection with the
2591 client first, then connect to the server. This old mode does
2592 not allow Squid to mimic server SSL certificate and does not
2593 work with intercepted SSL connections.
2594
2595 server-first
2596 Bump the connection. Establish a secure connection with the
2597 server first, then establish a secure connection with the
2598 client, using a mimicked server certificate. Works with both
2599 CONNECT requests and intercepted SSL connections, but does
2600 not allow to make decisions based on SSL handshake info.
2601
2602 peek-and-splice
2603 Decide whether to bump or splice the connection based on
2604 client-to-squid and server-to-squid SSL hello messages.
2605 XXX: Remove.
2606
2607 none
2608 Same as the "splice" action.
2609
2610 All ssl_bump rules are evaluated at each of the supported bumping
2611 steps. Rules with actions that are impossible at the current step are
2612 ignored. The first matching ssl_bump action wins and is applied at the
2613 end of the current step. If no rules match, the splice action is used.
2614 See the at_step ACL for a list of the supported SslBump steps.
2615
2616 This clause supports both fast and slow acl types.
2617 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2618
2619 See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
2620
2621
2622 # Example: Bump all requests except those originating from
2623 # localhost or those going to example.com.
2624
2625 acl broken_sites dstdomain .example.com
2626 ssl_bump splice localhost
2627 ssl_bump splice broken_sites
2628 ssl_bump bump all
2629DOC_END
2630
2631NAME: sslproxy_flags
2632IFDEF: USE_OPENSSL
2633DEFAULT: none
2634LOC: Config.ssl_client.flags
2635TYPE: string
2636DOC_START
2637 Various flags modifying the use of SSL while proxying https:// URLs:
2638 DONT_VERIFY_PEER Accept certificates that fail verification.
2639 For refined control, see sslproxy_cert_error.
2640 NO_DEFAULT_CA Don't use the default CA list built in
2641 to OpenSSL.
2642DOC_END
2643
2644NAME: sslproxy_cert_error
2645IFDEF: USE_OPENSSL
2646DEFAULT: none
2647DEFAULT_DOC: Server certificate errors terminate the transaction.
2648LOC: Config.ssl_client.cert_error
2649TYPE: acl_access
2650DOC_START
2651 Use this ACL to bypass server certificate validation errors.
2652
2653 For example, the following lines will bypass all validation errors
2654 when talking to servers for example.com. All other
2655 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2656
2657 acl BrokenButTrustedServers dstdomain example.com
2658 sslproxy_cert_error allow BrokenButTrustedServers
2659 sslproxy_cert_error deny all
2660
2661 This clause only supports fast acl types.
2662 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2663 Using slow acl types may result in server crashes
2664
2665 Without this option, all server certificate validation errors
2666 terminate the transaction to protect Squid and the client.
2667
2668 SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2669 but should not happen unless your OpenSSL library is buggy.
2670
2671 SECURITY WARNING:
2672 Bypassing validation errors is dangerous because an
2673 error usually implies that the server cannot be trusted
2674 and the connection may be insecure.
2675
2676 See also: sslproxy_flags and DONT_VERIFY_PEER.
2677DOC_END
2678
2679NAME: sslproxy_cert_sign
2680IFDEF: USE_OPENSSL
2681DEFAULT: none
2682POSTSCRIPTUM: signUntrusted ssl::certUntrusted
2683POSTSCRIPTUM: signSelf ssl::certSelfSigned
2684POSTSCRIPTUM: signTrusted all
2685TYPE: sslproxy_cert_sign
2686LOC: Config.ssl_client.cert_sign
2687DOC_START
2688
2689 sslproxy_cert_sign <signing algorithm> acl ...
2690
2691 The following certificate signing algorithms are supported:
2692
2693 signTrusted
2694 Sign using the configured CA certificate which is usually
2695 placed in and trusted by end-user browsers. This is the
2696 default for trusted origin server certificates.
2697
2698 signUntrusted
2699 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2700 This is the default for untrusted origin server certificates
2701 that are not self-signed (see ssl::certUntrusted).
2702
2703 signSelf
2704 Sign using a self-signed certificate with the right CN to
2705 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2706 browser. This is the default for self-signed origin server
2707 certificates (see ssl::certSelfSigned).
2708
2709 This clause only supports fast acl types.
2710
2711 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2712 signing algorithm to generate the certificate and ignores all
2713 subsequent sslproxy_cert_sign options (the first match wins). If no
2714 acl(s) match, the default signing algorithm is determined by errors
2715 detected when obtaining and validating the origin server certificate.
2716
2717 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2718 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2719 CONNECT request that carries a domain name. In all other cases (CONNECT
2720 to an IP address or an intercepted SSL connection), Squid cannot detect
2721 the domain mismatch at certificate generation time when
2722 bump-server-first is used.
2723DOC_END
2724
2725NAME: sslproxy_cert_adapt
2726IFDEF: USE_OPENSSL
2727DEFAULT: none
2728TYPE: sslproxy_cert_adapt
2729LOC: Config.ssl_client.cert_adapt
2730DOC_START
2731
2732 sslproxy_cert_adapt <adaptation algorithm> acl ...
2733
2734 The following certificate adaptation algorithms are supported:
2735
2736 setValidAfter
2737 Sets the "Not After" property to the "Not After" property of
2738 the CA certificate used to sign generated certificates.
2739
2740 setValidBefore
2741 Sets the "Not Before" property to the "Not Before" property of
2742 the CA certificate used to sign generated certificates.
2743
2744 setCommonName or setCommonName{CN}
2745 Sets Subject.CN property to the host name specified as a
2746 CN parameter or, if no explicit CN parameter was specified,
2747 extracted from the CONNECT request. It is a misconfiguration
2748 to use setCommonName without an explicit parameter for
2749 intercepted or tproxied SSL connections.
2750
2751 This clause only supports fast acl types.
2752
2753 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2754 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2755 corresponding adaptation algorithm to generate the certificate and
2756 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2757 group (i.e., the first match wins within each algorithm group). If no
2758 acl(s) match, the default mimicking action takes place.
2759
2760 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2761 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2762 CONNECT request that carries a domain name. In all other cases (CONNECT
2763 to an IP address or an intercepted SSL connection), Squid cannot detect
2764 the domain mismatch at certificate generation time when
2765 bump-server-first is used.
2766DOC_END
2767
2768NAME: sslpassword_program
2769IFDEF: USE_OPENSSL
2770DEFAULT: none
2771LOC: Config.Program.ssl_password
2772TYPE: string
2773DOC_START
2774 Specify a program used for entering SSL key passphrases
2775 when using encrypted SSL certificate keys. If not specified
2776 keys must either be unencrypted, or Squid started with the -N
2777 option to allow it to query interactively for the passphrase.
2778
2779 The key file name is given as argument to the program allowing
2780 selection of the right password if you have multiple encrypted
2781 keys.
2782DOC_END
2783
2784COMMENT_START
2785 OPTIONS RELATING TO EXTERNAL SSL_CRTD
2786 -----------------------------------------------------------------------------
2787COMMENT_END
2788
2789NAME: sslcrtd_program
2790TYPE: eol
2791IFDEF: USE_SSL_CRTD
2792DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
2793LOC: Ssl::TheConfig.ssl_crtd
2794DOC_START
2795 Specify the location and options of the executable for ssl_crtd process.
2796 @DEFAULT_SSL_CRTD@ program requires -s and -M parameters
2797 For more information use:
2798 @DEFAULT_SSL_CRTD@ -h
2799DOC_END
2800
2801NAME: sslcrtd_children
2802TYPE: HelperChildConfig
2803IFDEF: USE_SSL_CRTD
2804DEFAULT: 32 startup=5 idle=1
2805LOC: Ssl::TheConfig.ssl_crtdChildren
2806DOC_START
2807 The maximum number of processes spawn to service ssl server.
2808 The maximum this may be safely set to is 32.
2809
2810 The startup= and idle= options allow some measure of skew in your
2811 tuning.
2812
2813 startup=N
2814
2815 Sets the minimum number of processes to spawn when Squid
2816 starts or reconfigures. When set to zero the first request will
2817 cause spawning of the first child process to handle it.
2818
2819 Starting too few children temporary slows Squid under load while it
2820 tries to spawn enough additional processes to cope with traffic.
2821
2822 idle=N
2823
2824 Sets a minimum of how many processes Squid is to try and keep available
2825 at all times. When traffic begins to rise above what the existing
2826 processes can handle this many more will be spawned up to the maximum
2827 configured. A minimum setting of 1 is required.
2828
2829 queue-size=N
2830
2831 Sets the maximum number of queued requests.
2832 If the queued requests exceed queue size for more than 3 minutes
2833 squid aborts its operation.
2834 The default value is set to 2*numberofchildren.
2835
2836 You must have at least one ssl_crtd process.
2837DOC_END
2838
2839NAME: sslcrtvalidator_program
2840TYPE: eol
2841IFDEF: USE_OPENSSL
2842DEFAULT: none
2843LOC: Ssl::TheConfig.ssl_crt_validator
2844DOC_START
2845 Specify the location and options of the executable for ssl_crt_validator
2846 process.
2847
2848 Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2849
2850 Options:
2851 ttl=n TTL in seconds for cached results. The default is 60 secs
2852 cache=n limit the result cache size. The default value is 2048
2853DOC_END
2854
2855NAME: sslcrtvalidator_children
2856TYPE: HelperChildConfig
2857IFDEF: USE_OPENSSL
2858DEFAULT: 32 startup=5 idle=1 concurrency=1
2859LOC: Ssl::TheConfig.ssl_crt_validator_Children
2860DOC_START
2861 The maximum number of processes spawn to service SSL server.
2862 The maximum this may be safely set to is 32.
2863
2864 The startup= and idle= options allow some measure of skew in your
2865 tuning.
2866
2867 startup=N
2868
2869 Sets the minimum number of processes to spawn when Squid
2870 starts or reconfigures. When set to zero the first request will
2871 cause spawning of the first child process to handle it.
2872
2873 Starting too few children temporary slows Squid under load while it
2874 tries to spawn enough additional processes to cope with traffic.
2875
2876 idle=N
2877
2878 Sets a minimum of how many processes Squid is to try and keep available
2879 at all times. When traffic begins to rise above what the existing
2880 processes can handle this many more will be spawned up to the maximum
2881 configured. A minimum setting of 1 is required.
2882
2883 concurrency=
2884
2885 The number of requests each certificate validator helper can handle in
2886 parallel. A value of 0 indicates the certficate validator does not
2887 support concurrency. Defaults to 1.
2888
2889 When this directive is set to a value >= 1 then the protocol
2890 used to communicate with the helper is modified to include
2891 a request ID in front of the request/response. The request
2892 ID from the request must be echoed back with the response
2893 to that request.
2894
2895 queue-size=N
2896
2897 Sets the maximum number of queued requests.
2898 If the queued requests exceed queue size for more than 3 minutes
2899 squid aborts its operation.
2900 The default value is set to 2*numberofchildren.
2901
2902 You must have at least one ssl_crt_validator process.
2903DOC_END
2904
2905COMMENT_START
2906 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2907 -----------------------------------------------------------------------------
2908COMMENT_END
2909
2910NAME: cache_peer
2911TYPE: peer
2912DEFAULT: none
2913LOC: Config.peers
2914DOC_START
2915 To specify other caches in a hierarchy, use the format:
2916
2917 cache_peer hostname type http-port icp-port [options]
2918
2919 For example,
2920
2921 # proxy icp
2922 # hostname type port port options
2923 # -------------------- -------- ----- ----- -----------
2924 cache_peer parent.foo.net parent 3128 3130 default
2925 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2926 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2927 cache_peer example.com parent 80 0 default
2928 cache_peer cdn.example.com sibling 3128 0
2929
2930 type: either 'parent', 'sibling', or 'multicast'.
2931
2932 proxy-port: The port number where the peer accept HTTP requests.
2933 For other Squid proxies this is usually 3128
2934 For web servers this is usually 80
2935
2936 icp-port: Used for querying neighbor caches about objects.
2937 Set to 0 if the peer does not support ICP or HTCP.
2938 See ICP and HTCP options below for additional details.
2939
2940
2941 ==== ICP OPTIONS ====
2942
2943 You MUST also set icp_port and icp_access explicitly when using these options.
2944 The defaults will prevent peer traffic using ICP.
2945
2946
2947 no-query Disable ICP queries to this neighbor.
2948
2949 multicast-responder
2950 Indicates the named peer is a member of a multicast group.
2951 ICP queries will not be sent directly to the peer, but ICP
2952 replies will be accepted from it.
2953
2954 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2955 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2956
2957 background-ping
2958 To only send ICP queries to this neighbor infrequently.
2959 This is used to keep the neighbor round trip time updated
2960 and is usually used in conjunction with weighted-round-robin.
2961
2962
2963 ==== HTCP OPTIONS ====
2964
2965 You MUST also set htcp_port and htcp_access explicitly when using these options.
2966 The defaults will prevent peer traffic using HTCP.
2967
2968
2969 htcp Send HTCP, instead of ICP, queries to the neighbor.
2970 You probably also want to set the "icp-port" to 4827
2971 instead of 3130. This directive accepts a comma separated
2972 list of options described below.
2973
2974 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2975
2976 htcp=no-clr Send HTCP to the neighbor but without
2977 sending any CLR requests. This cannot be used with
2978 only-clr.
2979
2980 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2981 This cannot be used with no-clr.
2982
2983 htcp=no-purge-clr
2984 Send HTCP to the neighbor including CLRs but only when
2985 they do not result from PURGE requests.
2986
2987 htcp=forward-clr
2988 Forward any HTCP CLR requests this proxy receives to the peer.
2989
2990
2991 ==== PEER SELECTION METHODS ====
2992
2993 The default peer selection method is ICP, with the first responding peer
2994 being used as source. These options can be used for better load balancing.
2995
2996
2997 default This is a parent cache which can be used as a "last-resort"
2998 if a peer cannot be located by any of the peer-selection methods.
2999 If specified more than once, only the first is used.
3000
3001 round-robin Load-Balance parents which should be used in a round-robin
3002 fashion in the absence of any ICP queries.
3003 weight=N can be used to add bias.
3004
3005 weighted-round-robin
3006 Load-Balance parents which should be used in a round-robin
3007 fashion with the frequency of each parent being based on the
3008 round trip time. Closer parents are used more often.
3009 Usually used for background-ping parents.
3010 weight=N can be used to add bias.
3011
3012 carp Load-Balance parents which should be used as a CARP array.
3013 The requests will be distributed among the parents based on the
3014 CARP load balancing hash function based on their weight.
3015
3016 userhash Load-balance parents based on the client proxy_auth or ident username.
3017
3018 sourcehash Load-balance parents based on the client source IP.
3019
3020 multicast-siblings
3021 To be used only for cache peers of type "multicast".
3022 ALL members of this multicast group have "sibling"
3023 relationship with it, not "parent". This is to a multicast
3024 group when the requested object would be fetched only from
3025 a "parent" cache, anyway. It's useful, e.g., when
3026 configuring a pool of redundant Squid proxies, being
3027 members of the same multicast group.
3028
3029
3030 ==== PEER SELECTION OPTIONS ====
3031
3032 weight=N use to affect the selection of a peer during any weighted
3033 peer-selection mechanisms.
3034 The weight must be an integer; default is 1,
3035 larger weights are favored more.
3036 This option does not affect parent selection if a peering
3037 protocol is not in use.
3038
3039 basetime=N Specify a base amount to be subtracted from round trip
3040 times of parents.
3041 It is subtracted before division by weight in calculating
3042 which parent to fectch from. If the rtt is less than the
3043 base time the rtt is set to a minimal value.
3044
3045 ttl=N Specify a TTL to use when sending multicast ICP queries
3046 to this address.
3047 Only useful when sending to a multicast group.
3048 Because we don't accept ICP replies from random
3049 hosts, you must configure other group members as
3050 peers with the 'multicast-responder' option.
3051
3052 no-delay To prevent access to this neighbor from influencing the
3053 delay pools.
3054
3055 digest-url=URL Tell Squid to fetch the cache digest (if digests are
3056 enabled) for this host from the specified URL rather
3057 than the Squid default location.
3058
3059
3060 ==== CARP OPTIONS ====
3061
3062 carp-key=key-specification
3063 use a different key than the full URL to hash against the peer.
3064 the key-specification is a comma-separated list of the keywords
3065 scheme, host, port, path, params
3066 Order is not important.
3067
3068 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
3069
3070 originserver Causes this parent to be contacted as an origin server.
3071 Meant to be used in accelerator setups when the peer
3072 is a web server.
3073
3074 forceddomain=name
3075 Set the Host header of requests forwarded to this peer.
3076 Useful in accelerator setups where the server (peer)
3077 expects a certain domain name but clients may request
3078 others. ie example.com or www.example.com
3079
3080 no-digest Disable request of cache digests.
3081
3082 no-netdb-exchange
3083 Disables requesting ICMP RTT database (NetDB).
3084
3085
3086 ==== AUTHENTICATION OPTIONS ====
3087
3088 login=user:password
3089 If this is a personal/workgroup proxy and your parent
3090 requires proxy authentication.
3091
3092 Note: The string can include URL escapes (i.e. %20 for
3093 spaces). This also means % must be written as %%.
3094
3095 login=PASSTHRU
3096 Send login details received from client to this peer.
3097 Both Proxy- and WWW-Authorization headers are passed
3098 without alteration to the peer.
3099 Authentication is not required by Squid for this to work.
3100
3101 Note: This will pass any form of authentication but
3102 only Basic auth will work through a proxy unless the
3103 connection-auth options are also used.
3104
3105 login=PASS Send login details received from client to this peer.
3106 Authentication is not required by this option.
3107
3108 If there are no client-provided authentication headers
3109 to pass on, but username and password are available
3110 from an external ACL user= and password= result tags
3111 they may be sent instead.
3112
3113 Note: To combine this with proxy_auth both proxies must
3114 share the same user database as HTTP only allows for
3115 a single login (one for proxy, one for origin server).
3116 Also be warned this will expose your users proxy
3117 password to the peer. USE WITH CAUTION
3118
3119 login=*:password
3120 Send the username to the upstream cache, but with a
3121 fixed password. This is meant to be used when the peer
3122 is in another administrative domain, but it is still
3123 needed to identify each user.
3124 The star can optionally be followed by some extra
3125 information which is added to the username. This can
3126 be used to identify this proxy to the peer, similar to
3127 the login=username:password option above.
3128
3129 login=NEGOTIATE
3130 If this is a personal/workgroup proxy and your parent
3131 requires a secure proxy authentication.
3132 The first principal from the default keytab or defined by
3133 the environment variable KRB5_KTNAME will be used.
3134
3135 WARNING: The connection may transmit requests from multiple
3136 clients. Negotiate often assumes end-to-end authentication
3137 and a single-client. Which is not strictly true here.
3138
3139 login=NEGOTIATE:principal_name
3140 If this is a personal/workgroup proxy and your parent
3141 requires a secure proxy authentication.
3142 The principal principal_name from the default keytab or
3143 defined by the environment variable KRB5_KTNAME will be
3144 used.
3145
3146 WARNING: The connection may transmit requests from multiple
3147 clients. Negotiate often assumes end-to-end authentication
3148 and a single-client. Which is not strictly true here.
3149
3150 connection-auth=on|off
3151 Tell Squid that this peer does or not support Microsoft
3152 connection oriented authentication, and any such
3153 challenges received from there should be ignored.
3154 Default is auto to automatically determine the status
3155 of the peer.
3156
3157
3158 ==== SSL / HTTPS / TLS OPTIONS ====
3159
3160 ssl Encrypt connections to this peer with SSL/TLS.
3161
3162 sslcert=/path/to/ssl/certificate
3163 A client SSL certificate to use when connecting to
3164 this peer.
3165
3166 sslkey=/path/to/ssl/key
3167 The private SSL key corresponding to sslcert above.
3168 If 'sslkey' is not specified 'sslcert' is assumed to
3169 reference a combined file containing both the
3170 certificate and the key.
3171
3172 sslversion=1|3|4|5|6
3173 The SSL version to use when connecting to this peer
3174 1 = automatic (default)
3175 3 = SSL v3 only
3176 4 = TLS v1.0 only
3177 5 = TLS v1.1 only
3178 6 = TLS v1.2 only
3179
3180 sslcipher=... The list of valid SSL ciphers to use when connecting
3181 to this peer.
3182
3183 ssloptions=... Specify various SSL implementation options:
3184
3185 NO_SSLv3 Disallow the use of SSLv3
3186 NO_TLSv1 Disallow the use of TLSv1.0
3187 NO_TLSv1_1 Disallow the use of TLSv1.1
3188 NO_TLSv1_2 Disallow the use of TLSv1.2
3189 SINGLE_DH_USE
3190 Always create a new key when using
3191 temporary/ephemeral DH key exchanges
3192 ALL Enable various bug workarounds
3193 suggested as "harmless" by OpenSSL
3194 Be warned that this reduces SSL/TLS
3195 strength to some attacks.
3196
3197 See the OpenSSL SSL_CTX_set_options documentation for a
3198 more complete list.
3199
3200 sslcafile=... A file containing additional CA certificates to use
3201 when verifying the peer certificate.
3202
3203 sslcapath=... A directory containing additional CA certificates to
3204 use when verifying the peer certificate.
3205
3206 sslcrlfile=... A certificate revocation list file to use when
3207 verifying the peer certificate.
3208
3209 sslflags=... Specify various flags modifying the SSL implementation:
3210
3211 DONT_VERIFY_PEER
3212 Accept certificates even if they fail to
3213 verify.
3214 NO_DEFAULT_CA
3215 Don't use the default CA list built in
3216 to OpenSSL.
3217 DONT_VERIFY_DOMAIN
3218 Don't verify the peer certificate
3219 matches the server name
3220
3221 ssldomain= The peer name as advertised in it's certificate.
3222 Used for verifying the correctness of the received peer
3223 certificate. If not specified the peer hostname will be
3224 used.
3225
3226 front-end-https
3227 Enable the "Front-End-Https: On" header needed when
3228 using Squid as a SSL frontend in front of Microsoft OWA.
3229 See MS KB document Q307347 for details on this header.
3230 If set to auto the header will only be added if the
3231 request is forwarded as a https:// URL.
3232
3233
3234 ==== GENERAL OPTIONS ====
3235
3236 connect-timeout=N
3237 A peer-specific connect timeout.
3238 Also see the peer_connect_timeout directive.
3239
3240 connect-fail-limit=N
3241 How many times connecting to a peer must fail before
3242 it is marked as down. Standby connection failures
3243 count towards this limit. Default is 10.
3244
3245 allow-miss Disable Squid's use of only-if-cached when forwarding
3246 requests to siblings. This is primarily useful when
3247 icp_hit_stale is used by the sibling. To extensive use
3248 of this option may result in forwarding loops, and you
3249 should avoid having two-way peerings with this option.
3250 For example to deny peer usage on requests from peer
3251 by denying cache_peer_access if the source is a peer.
3252
3253 max-conn=N Limit the number of concurrent connections the Squid
3254 may open to this peer, including already opened idle
3255 and standby connections. There is no peer-specific
3256 connection limit by default.
3257
3258 A peer exceeding the limit is not used for new
3259 requests unless a standby connection is available.
3260
3261 max-conn currently works poorly with idle persistent
3262 connections: When a peer reaches its max-conn limit,
3263 and there are idle persistent connections to the peer,
3264 the peer may not be selected because the limiting code
3265 does not know whether Squid can reuse those idle
3266 connections.
3267
3268 standby=N Maintain a pool of N "hot standby" connections to an
3269 UP peer, available for requests when no idle
3270 persistent connection is available (or safe) to use.
3271 By default and with zero N, no such pool is maintained.
3272 N must not exceed the max-conn limit (if any).
3273
3274 At start or after reconfiguration, Squid opens new TCP
3275 standby connections until there are N connections
3276 available and then replenishes the standby pool as
3277 opened connections are used up for requests. A used
3278 connection never goes back to the standby pool, but
3279 may go to the regular idle persistent connection pool
3280 shared by all peers and origin servers.
3281
3282 Squid never opens multiple new standby connections
3283 concurrently. This one-at-a-time approach minimizes
3284 flooding-like effect on peers. Furthermore, just a few
3285 standby connections should be sufficient in most cases
3286 to supply most new requests with a ready-to-use
3287 connection.
3288
3289 Standby connections obey server_idle_pconn_timeout.
3290 For the feature to work as intended, the peer must be
3291 configured to accept and keep them open longer than
3292 the idle timeout at the connecting Squid, to minimize
3293 race conditions typical to idle used persistent
3294 connections. Default request_timeout and
3295 server_idle_pconn_timeout values ensure such a
3296 configuration.
3297
3298 name=xxx Unique name for the peer.
3299 Required if you have multiple peers on the same host
3300 but different ports.
3301 This name can be used in cache_peer_access and similar
3302 directives to dentify the peer.
3303 Can be used by outgoing access controls through the
3304 peername ACL type.
3305
3306 no-tproxy Do not use the client-spoof TPROXY support when forwarding
3307 requests to this peer. Use normal address selection instead.
3308 This overrides the spoof_client_ip ACL.
3309
3310 proxy-only objects fetched from the peer will not be stored locally.
3311
3312DOC_END
3313
3314NAME: cache_peer_domain cache_host_domain
3315TYPE: hostdomain
3316DEFAULT: none
3317LOC: none
3318DOC_START
3319 Use to limit the domains for which a neighbor cache will be
3320 queried.
3321
3322 Usage:
3323 cache_peer_domain cache-host domain [domain ...]
3324 cache_peer_domain cache-host !domain
3325
3326 For example, specifying
3327
3328 cache_peer_domain parent.foo.net .edu
3329
3330 has the effect such that UDP query packets are sent to
3331 'bigserver' only when the requested object exists on a
3332 server in the .edu domain. Prefixing the domainname
3333 with '!' means the cache will be queried for objects
3334 NOT in that domain.
3335
3336 NOTE: * Any number of domains may be given for a cache-host,
3337 either on the same or separate lines.
3338 * When multiple domains are given for a particular
3339 cache-host, the first matched domain is applied.
3340 * Cache hosts with no domain restrictions are queried
3341 for all requests.
3342 * There are no defaults.
3343 * There is also a 'cache_peer_access' tag in the ACL
3344 section.
3345DOC_END
3346
3347NAME: cache_peer_access
3348TYPE: peer_access
3349DEFAULT: none
3350LOC: none
3351DOC_START
3352 Similar to 'cache_peer_domain' but provides more flexibility by
3353 using ACL elements.
3354
3355 Usage:
3356 cache_peer_access cache-host allow|deny [!]aclname ...
3357
3358 The syntax is identical to 'http_access' and the other lists of
3359 ACL elements. See the comments for 'http_access' below, or
3360 the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
3361DOC_END
3362
3363NAME: neighbor_type_domain
3364TYPE: hostdomaintype
3365DEFAULT: none
3366DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
3367LOC: none
3368DOC_START
3369 Modify the cache_peer neighbor type when passing requests
3370 about specific domains to the peer.
3371
3372 Usage:
3373 neighbor_type_domain neighbor parent|sibling domain domain ...
3374
3375 For example:
3376 cache_peer foo.example.com parent 3128 3130
3377 neighbor_type_domain foo.example.com sibling .au .de
3378
3379 The above configuration treats all requests to foo.example.com as a
3380 parent proxy unless the request is for a .au or .de ccTLD domain name.
3381DOC_END
3382
3383NAME: dead_peer_timeout
3384COMMENT: (seconds)
3385DEFAULT: 10 seconds
3386TYPE: time_t
3387LOC: Config.Timeout.deadPeer
3388DOC_START
3389 This controls how long Squid waits to declare a peer cache
3390 as "dead." If there are no ICP replies received in this
3391 amount of time, Squid will declare the peer dead and not
3392 expect to receive any further ICP replies. However, it
3393 continues to send ICP queries, and will mark the peer as
3394 alive upon receipt of the first subsequent ICP reply.
3395
3396 This timeout also affects when Squid expects to receive ICP
3397 replies from peers. If more than 'dead_peer' seconds have
3398 passed since the last ICP reply was received, Squid will not
3399 expect to receive an ICP reply on the next query. Thus, if
3400 your time between requests is greater than this timeout, you
3401 will see a lot of requests sent DIRECT to origin servers
3402 instead of to your parents.
3403DOC_END
3404
3405NAME: forward_max_tries
3406DEFAULT: 25
3407TYPE: int
3408LOC: Config.forward_max_tries
3409DOC_START
3410 Controls how many different forward paths Squid will try
3411 before giving up. See also forward_timeout.
3412
3413 NOTE: connect_retries (default: none) can make each of these
3414 possible forwarding paths be tried multiple times.
3415DOC_END
3416
3417COMMENT_START
3418 MEMORY CACHE OPTIONS
3419 -----------------------------------------------------------------------------
3420COMMENT_END
3421
3422NAME: cache_mem
3423COMMENT: (bytes)
3424TYPE: b_size_t
3425DEFAULT: 256 MB
3426LOC: Config.memMaxSize
3427DOC_START
3428 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3429 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3430 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3431 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3432
3433 'cache_mem' specifies the ideal amount of memory to be used
3434 for:
3435 * In-Transit objects
3436 * Hot Objects
3437 * Negative-Cached objects
3438
3439 Data for these objects are stored in 4 KB blocks. This
3440 parameter specifies the ideal upper limit on the total size of
3441 4 KB blocks allocated. In-Transit objects take the highest
3442 priority.
3443
3444 In-transit objects have priority over the others. When
3445 additional space is needed for incoming data, negative-cached
3446 and hot objects will be released. In other words, the
3447 negative-cached and hot objects will fill up any unused space
3448 not needed for in-transit objects.
3449
3450 If circumstances require, this limit will be exceeded.
3451 Specifically, if your incoming request rate requires more than
3452 'cache_mem' of memory to hold in-transit objects, Squid will
3453 exceed this limit to satisfy the new requests. When the load
3454 decreases, blocks will be freed until the high-water mark is
3455 reached. Thereafter, blocks will be used to store hot
3456 objects.
3457
3458 If shared memory caching is enabled, Squid does not use the shared
3459 cache space for in-transit objects, but they still consume as much
3460 local memory as they need. For more details about the shared memory
3461 cache, see memory_cache_shared.
3462DOC_END
3463
3464NAME: maximum_object_size_in_memory
3465COMMENT: (bytes)
3466TYPE: b_size_t
3467DEFAULT: 512 KB
3468LOC: Config.Store.maxInMemObjSize
3469DOC_START
3470 Objects greater than this size will not be attempted to kept in
3471 the memory cache. This should be set high enough to keep objects
3472 accessed frequently in memory to improve performance whilst low
3473 enough to keep larger objects from hoarding cache_mem.
3474DOC_END
3475
3476NAME: memory_cache_shared
3477COMMENT: on|off
3478TYPE: YesNoNone
3479LOC: Config.memShared
3480DEFAULT: none
3481DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
3482DOC_START
3483 Controls whether the memory cache is shared among SMP workers.
3484
3485 The shared memory cache is meant to occupy cache_mem bytes and replace
3486 the non-shared memory cache, although some entities may still be
3487 cached locally by workers for now (e.g., internal and in-transit
3488 objects may be served from a local memory cache even if shared memory
3489 caching is enabled).
3490
3491 By default, the memory cache is shared if and only if all of the
3492 following conditions are satisfied: Squid runs in SMP mode with
3493 multiple workers, cache_mem is positive, and Squid environment
3494 supports required IPC primitives (e.g., POSIX shared memory segments
3495 and GCC-style atomic operations).
3496
3497 To avoid blocking locks, shared memory uses opportunistic algorithms
3498 that do not guarantee that every cachable entity that could have been
3499 shared among SMP workers will actually be shared.
3500
3501 Currently, entities exceeding 32KB in size cannot be shared.
3502DOC_END
3503
3504NAME: memory_cache_mode
3505TYPE: memcachemode
3506LOC: Config
3507DEFAULT: always
3508DEFAULT_DOC: Keep the most recently fetched objects in memory
3509DOC_START
3510 Controls which objects to keep in the memory cache (cache_mem)
3511
3512 always Keep most recently fetched objects in memory (default)
3513
3514 disk Only disk cache hits are kept in memory, which means
3515 an object must first be cached on disk and then hit
3516 a second time before cached in memory.
3517
3518 network Only objects fetched from network is kept in memory
3519DOC_END
3520
3521NAME: memory_replacement_policy
3522TYPE: removalpolicy
3523LOC: Config.memPolicy
3524DEFAULT: lru
3525DOC_START
3526 The memory replacement policy parameter determines which
3527 objects are purged from memory when memory space is needed.
3528
3529 See cache_replacement_policy for details on algorithms.
3530DOC_END
3531
3532COMMENT_START
3533 DISK CACHE OPTIONS
3534 -----------------------------------------------------------------------------
3535COMMENT_END
3536
3537NAME: cache_replacement_policy
3538TYPE: removalpolicy
3539LOC: Config.replPolicy
3540DEFAULT: lru
3541DOC_START
3542 The cache replacement policy parameter determines which
3543 objects are evicted (replaced) when disk space is needed.
3544
3545 lru : Squid's original list based LRU policy
3546 heap GDSF : Greedy-Dual Size Frequency
3547 heap LFUDA: Least Frequently Used with Dynamic Aging
3548 heap LRU : LRU policy implemented using a heap
3549
3550 Applies to any cache_dir lines listed below this directive.
3551
3552 The LRU policies keeps recently referenced objects.
3553
3554 The heap GDSF policy optimizes object hit rate by keeping smaller
3555 popular objects in cache so it has a better chance of getting a
3556 hit. It achieves a lower byte hit rate than LFUDA though since
3557 it evicts larger (possibly popular) objects.
3558
3559 The heap LFUDA policy keeps popular objects in cache regardless of
3560 their size and thus optimizes byte hit rate at the expense of
3561 hit rate since one large, popular object will prevent many
3562 smaller, slightly less popular objects from being cached.
3563
3564 Both policies utilize a dynamic aging mechanism that prevents
3565 cache pollution that can otherwise occur with frequency-based
3566 replacement policies.
3567
3568 NOTE: if using the LFUDA replacement policy you should increase
3569 the value of maximum_object_size above its default of 4 MB to
3570 to maximize the potential byte hit rate improvement of LFUDA.
3571
3572 For more information about the GDSF and LFUDA cache replacement
3573 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3574 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3575DOC_END
3576
3577NAME: minimum_object_size
3578COMMENT: (bytes)
3579TYPE: b_int64_t
3580DEFAULT: 0 KB
3581DEFAULT_DOC: no limit
3582LOC: Config.Store.minObjectSize
3583DOC_START
3584 Objects smaller than this size will NOT be saved on disk. The
3585 value is specified in bytes, and the default is 0 KB, which
3586 means all responses can be stored.
3587DOC_END
3588
3589NAME: maximum_object_size
3590COMMENT: (bytes)
3591TYPE: b_int64_t
3592DEFAULT: 4 MB
3593LOC: Config.Store.maxObjectSize
3594DOC_START
3595 Set the default value for max-size parameter on any cache_dir.
3596 The value is specified in bytes, and the default is 4 MB.
3597
3598 If you wish to get a high BYTES hit ratio, you should probably
3599 increase this (one 32 MB object hit counts for 3200 10KB
3600 hits).
3601
3602 If you wish to increase hit ratio more than you want to
3603 save bandwidth you should leave this low.
3604
3605 NOTE: if using the LFUDA replacement policy you should increase
3606 this value to maximize the byte hit rate improvement of LFUDA!
3607 See cache_replacement_policy for a discussion of this policy.
3608DOC_END
3609
3610NAME: cache_dir
3611TYPE: cachedir
3612DEFAULT: none
3613DEFAULT_DOC: No disk cache. Store cache ojects only in memory.
3614LOC: Config.cacheSwap
3615DOC_START
3616 Format:
3617 cache_dir Type Directory-Name Fs-specific-data [options]
3618
3619 You can specify multiple cache_dir lines to spread the
3620 cache among different disk partitions.
3621
3622 Type specifies the kind of storage system to use. Only "ufs"
3623 is built by default. To enable any of the other storage systems
3624 see the --enable-storeio configure option.
3625
3626 'Directory' is a top-level directory where cache swap
3627 files will be stored. If you want to use an entire disk
3628 for caching, this can be the mount-point directory.
3629 The directory must exist and be writable by the Squid
3630 process. Squid will NOT create this directory for you.
3631
3632 In SMP configurations, cache_dir must not precede the workers option
3633 and should use configuration macros or conditionals to give each
3634 worker interested in disk caching a dedicated cache directory.
3635
3636
3637 ==== The ufs store type ====
3638
3639 "ufs" is the old well-known Squid storage format that has always
3640 been there.
3641
3642 Usage:
3643 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3644
3645 'Mbytes' is the amount of disk space (MB) to use under this
3646 directory. The default is 100 MB. Change this to suit your
3647 configuration. Do NOT put the size of your disk drive here.
3648 Instead, if you want Squid to use the entire disk drive,
3649 subtract 20% and use that value.
3650
3651 'L1' is the number of first-level subdirectories which
3652 will be created under the 'Directory'. The default is 16.
3653
3654 'L2' is the number of second-level subdirectories which
3655 will be created under each first-level directory. The default
3656 is 256.
3657
3658
3659 ==== The aufs store type ====
3660
3661 "aufs" uses the same storage format as "ufs", utilizing
3662 POSIX-threads to avoid blocking the main Squid process on
3663 disk-I/O. This was formerly known in Squid as async-io.
3664
3665 Usage:
3666 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3667
3668 see argument descriptions under ufs above
3669
3670
3671 ==== The diskd store type ====
3672
3673 "diskd" uses the same storage format as "ufs", utilizing a
3674 separate process to avoid blocking the main Squid process on
3675 disk-I/O.
3676
3677 Usage:
3678 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3679
3680 see argument descriptions under ufs above
3681
3682 Q1 specifies the number of unacknowledged I/O requests when Squid
3683 stops opening new files. If this many messages are in the queues,
3684 Squid won't open new files. Default is 64
3685
3686 Q2 specifies the number of unacknowledged messages when Squid
3687 starts blocking. If this many messages are in the queues,
3688 Squid blocks until it receives some replies. Default is 72
3689
3690 When Q1 < Q2 (the default), the cache directory is optimized
3691 for lower response time at the expense of a decrease in hit
3692 ratio. If Q1 > Q2, the cache directory is optimized for
3693 higher hit ratio at the expense of an increase in response
3694 time.
3695
3696
3697 ==== The rock store type ====
3698
3699 Usage:
3700 cache_dir rock Directory-Name Mbytes [options]
3701
3702 The Rock Store type is a database-style storage. All cached
3703 entries are stored in a "database" file, using fixed-size slots.
3704 A single entry occupies one or more slots.
3705
3706 If possible, Squid using Rock Store creates a dedicated kid
3707 process called "disker" to avoid blocking Squid worker(s) on disk
3708 I/O. One disker kid is created for each rock cache_dir. Diskers
3709 are created only when Squid, running in daemon mode, has support
3710 for the IpcIo disk I/O module.
3711
3712 swap-timeout=msec: Squid will not start writing a miss to or
3713 reading a hit from disk if it estimates that the swap operation
3714 will take more than the specified number of milliseconds. By
3715 default and when set to zero, disables the disk I/O time limit
3716 enforcement. Ignored when using blocking I/O module because
3717 blocking synchronous I/O does not allow Squid to estimate the
3718 expected swap wait time.
3719
3720 max-swap-rate=swaps/sec: Artificially limits disk access using
3721 the specified I/O rate limit. Swap out requests that
3722 would cause the average I/O rate to exceed the limit are
3723 delayed. Individual swap in requests (i.e., hits or reads) are
3724 not delayed, but they do contribute to measured swap rate and
3725 since they are placed in the same FIFO queue as swap out
3726 requests, they may wait longer if max-swap-rate is smaller.
3727 This is necessary on file systems that buffer "too
3728 many" writes and then start blocking Squid and other processes
3729 while committing those writes to disk. Usually used together
3730 with swap-timeout to avoid excessive delays and queue overflows
3731 when disk demand exceeds available disk "bandwidth". By default
3732 and when set to zero, disables the disk I/O rate limit
3733 enforcement. Currently supported by IpcIo module only.
3734
3735 slot-size=bytes: The size of a database "record" used for
3736 storing cached responses. A cached response occupies at least
3737 one slot and all database I/O is done using individual slots so
3738 increasing this parameter leads to more disk space waste while
3739 decreasing it leads to more disk I/O overheads. Should be a
3740 multiple of your operating system I/O page size. Defaults to
3741 16KBytes. A housekeeping header is stored with each slot and
3742 smaller slot-sizes will be rejected. The header is smaller than
3743 100 bytes.
3744
3745
3746 ==== COMMON OPTIONS ====
3747
3748 no-store no new objects should be stored to this cache_dir.
3749
3750 min-size=n the minimum object size in bytes this cache_dir
3751 will accept. It's used to restrict a cache_dir
3752 to only store large objects (e.g. AUFS) while
3753 other stores are optimized for smaller objects
3754 (e.g. Rock).
3755 Defaults to 0.
3756
3757 max-size=n the maximum object size in bytes this cache_dir
3758 supports.
3759 The value in maximum_object_size directive sets
3760 the default unless more specific details are
3761 available (ie a small store capacity).
3762
3763 Note: To make optimal use of the max-size limits you should order
3764 the cache_dir lines with the smallest max-size value first.
3765
3766NOCOMMENT_START
3767
3768# Uncomment and adjust the following to add a disk cache directory.
3769#cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
3770NOCOMMENT_END
3771DOC_END
3772
3773NAME: store_dir_select_algorithm
3774TYPE: string
3775LOC: Config.store_dir_select_algorithm
3776DEFAULT: least-load
3777DOC_START
3778 How Squid selects which cache_dir to use when the response
3779 object will fit into more than one.
3780
3781 Regardless of which algorithm is used the cache_dir min-size
3782 and max-size parameters are obeyed. As such they can affect
3783 the selection algorithm by limiting the set of considered
3784 cache_dir.
3785
3786 Algorithms:
3787
3788 least-load
3789
3790 This algorithm is suited to caches with similar cache_dir
3791 sizes and disk speeds.
3792
3793 The disk with the least I/O pending is selected.
3794 When there are multiple disks with the same I/O load ranking
3795 the cache_dir with most available capacity is selected.
3796
3797 When a mix of cache_dir sizes are configured the faster disks
3798 have a naturally lower I/O loading and larger disks have more
3799 capacity. So space used to store objects and data throughput
3800 may be very unbalanced towards larger disks.
3801
3802
3803 round-robin
3804
3805 This algorithm is suited to caches with unequal cache_dir
3806 disk sizes.
3807
3808 Each cache_dir is selected in a rotation. The next suitable
3809 cache_dir is used.
3810
3811 Available cache_dir capacity is only considered in relation
3812 to whether the object will fit and meets the min-size and
3813 max-size parameters.
3814
3815 Disk I/O loading is only considered to prevent overload on slow
3816 disks. This algorithm does not spread objects by size, so any
3817 I/O loading per-disk may appear very unbalanced and volatile.
3818
3819 If several cache_dirs use similar min-size, max-size, or other
3820 limits to to reject certain responses, then do not group such
3821 cache_dir lines together, to avoid round-robin selection bias
3822 towards the first cache_dir after the group. Instead, interleave
3823 cache_dir lines from different groups. For example:
3824
3825 store_dir_select_algorithm round-robin
3826 cache_dir rock /hdd1 ... min-size=100000
3827 cache_dir rock /ssd1 ... max-size=99999
3828 cache_dir rock /hdd2 ... min-size=100000
3829 cache_dir rock /ssd2 ... max-size=99999
3830 cache_dir rock /hdd3 ... min-size=100000
3831 cache_dir rock /ssd3 ... max-size=99999
3832DOC_END
3833
3834NAME: max_open_disk_fds
3835TYPE: int
3836LOC: Config.max_open_disk_fds
3837DEFAULT: 0
3838DEFAULT_DOC: no limit
3839DOC_START
3840 To avoid having disk as the I/O bottleneck Squid can optionally
3841 bypass the on-disk cache if more than this amount of disk file
3842 descriptors are open.
3843
3844 A value of 0 indicates no limit.
3845DOC_END
3846
3847NAME: cache_swap_low
3848COMMENT: (percent, 0-100)
3849TYPE: int
3850DEFAULT: 90
3851LOC: Config.Swap.lowWaterMark
3852DOC_START
3853 The low-water mark for cache object replacement.
3854 Replacement begins when the swap (disk) usage is above the
3855 low-water mark and attempts to maintain utilization near the
3856 low-water mark. As swap utilization gets close to high-water
3857 mark object eviction becomes more aggressive. If utilization is
3858 close to the low-water mark less replacement is done each time.
3859
3860 Defaults are 90% and 95%. If you have a large cache, 5% could be
3861 hundreds of MB. If this is the case you may wish to set these
3862 numbers closer together.
3863
3864 See also cache_swap_high
3865DOC_END
3866
3867NAME: cache_swap_high
3868COMMENT: (percent, 0-100)
3869TYPE: int
3870DEFAULT: 95
3871LOC: Config.Swap.highWaterMark
3872DOC_START
3873 The high-water mark for cache object replacement.
3874 Replacement begins when the swap (disk) usage is above the
3875 low-water mark and attempts to maintain utilization near the
3876 low-water mark. As swap utilization gets close to high-water
3877 mark object eviction becomes more aggressive. If utilization is
3878 close to the low-water mark less replacement is done each time.
3879
3880 Defaults are 90% and 95%. If you have a large cache, 5% could be
3881 hundreds of MB. If this is the case you may wish to set these
3882 numbers closer together.
3883
3884 See also cache_swap_low
3885DOC_END
3886
3887COMMENT_START
3888 LOGFILE OPTIONS
3889 -----------------------------------------------------------------------------
3890COMMENT_END
3891
3892NAME: logformat
3893TYPE: logformat
3894LOC: Log::TheConfig
3895DEFAULT: none
3896DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
3897DOC_START
3898 Usage:
3899
3900 logformat <name> <format specification>
3901
3902 Defines an access log format.
3903
3904 The <format specification> is a string with embedded % format codes
3905
3906 % format codes all follow the same basic structure where all but
3907 the formatcode is optional. Output strings are automatically escaped
3908 as required according to their context and the output format
3909 modifiers are usually not needed, but can be specified if an explicit
3910 output format is desired.
3911
3912 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3913
3914 " output in quoted string format
3915 [ output in squid text log format as used by log_mime_hdrs
3916 # output in URL quoted format
3917 ' output as-is
3918
3919 - left aligned
3920
3921 width minimum and/or maximum field width:
3922 [width_min][.width_max]
3923 When minimum starts with 0, the field is zero-padded.
3924 String values exceeding maximum width are truncated.
3925
3926 {arg} argument such as header name etc
3927
3928 Format codes:
3929
3930 % a literal % character
3931 sn Unique sequence number per log line entry
3932 err_code The ID of an error response served by Squid or
3933 a similar internal error identifier.
3934 err_detail Additional err_code-dependent error information.
3935 note The annotation specified by the argument. Also
3936 logs the adaptation meta headers set by the
3937 adaptation_meta configuration parameter.
3938 If no argument given all annotations logged.
3939 The argument may include a separator to use with
3940 annotation values:
3941 name[:separator]
3942 By default, multiple note values are separated with ","
3943 and multiple notes are separated with "\r\n".
3944 When logging named notes with %{name}note, the
3945 explicitly configured separator is used between note
3946 values. When logging all notes with %note, the
3947 explicitly configured separator is used between
3948 individual notes. There is currently no way to
3949 specify both value and notes separators when logging
3950 all notes with %note.
3951
3952 Connection related format codes:
3953
3954 >a Client source IP address
3955 >A Client FQDN
3956 >p Client source port
3957 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3958 >la Local IP address the client connected to
3959 >lp Local port number the client connected to
3960 >qos Client connection TOS/DSCP value set by Squid
3961 >nfmark Client connection netfilter mark set by Squid
3962
3963 la Local listening IP address the client connection was connected to.
3964 lp Local listening port number the client connection was connected to.
3965
3966 <a Server IP address of the last server or peer connection
3967 <A Server FQDN or peer name
3968 <p Server port number of the last server or peer connection
3969 <la Local IP address of the last server or peer connection
3970 <lp Local port number of the last server or peer connection
3971 <qos Server connection TOS/DSCP value set by Squid
3972 <nfmark Server connection netfilter mark set by Squid
3973
3974 Time related format codes:
3975
3976 ts Seconds since epoch
3977 tu subsecond time (milliseconds)
3978 tl Local time. Optional strftime format argument
3979 default %d/%b/%Y:%H:%M:%S %z
3980 tg GMT time. Optional strftime format argument
3981 default %d/%b/%Y:%H:%M:%S %z
3982 tr Response time (milliseconds)
3983 dt Total time spent making DNS lookups (milliseconds)
3984 tS Approximate master transaction start time in
3985 <full seconds since epoch>.<fractional seconds> format.
3986 Currently, Squid considers the master transaction
3987 started when a complete HTTP request header initiating
3988 the transaction is received from the client. This is
3989 the same value that Squid uses to calculate transaction
3990 response time when logging %tr to access.log. Currently,
3991 Squid uses millisecond resolution for %tS values,
3992 similar to the default access.log "current time" field
3993 (%ts.%03tu).
3994
3995 Access Control related format codes:
3996
3997 et Tag returned by external acl
3998 ea Log string returned by external acl
3999 un User name (any available)
4000 ul User name from authentication
4001 ue User name from external acl helper
4002 ui User name from ident
4003 us User name from SSL
4004 credentials Client credentials. The exact meaning depends on
4005 the authentication scheme: For Basic authentication,
4006 it is the password; for Digest, the realm sent by the
4007 client; for NTLM and Negotiate, the client challenge
4008 or client credentials prefixed with "YR " or "KK ".
4009
4010 HTTP related format codes:
4011
4012 REQUEST
4013
4014 [http::]rm Request method (GET/POST etc)
4015 [http::]>rm Request method from client
4016 [http::]<rm Request method sent to server or peer
4017 [http::]ru Request URL from client (historic, filtered for logging)
4018 [http::]>ru Request URL from client
4019 [http::]<ru Request URL sent to server or peer
4020 [http::]>rs Request URL scheme from client
4021 [http::]<rs Request URL scheme sent to server or peer
4022 [http::]>rd Request URL domain from client
4023 [http::]<rd Request URL domain sent to server or peer
4024 [http::]>rP Request URL port from client
4025 [http::]<rP Request URL port sent to server or peer
4026 [http::]rp Request URL path excluding hostname
4027 [http::]>rp Request URL path excluding hostname from client
4028 [http::]<rp Request URL path excluding hostname sent to server or peer
4029 [http::]rv Request protocol version
4030 [http::]>rv Request protocol version from client
4031 [http::]<rv Request protocol version sent to server or peer
4032
4033 [http::]>h Original received request header.
4034 Usually differs from the request header sent by
4035 Squid, although most fields are often preserved.
4036 Accepts optional header field name/value filter
4037 argument using name[:[separator]element] format.
4038 [http::]>ha Received request header after adaptation and
4039 redirection (pre-cache REQMOD vectoring point).
4040 Usually differs from the request header sent by
4041 Squid, although most fields are often preserved.
4042 Optional header name argument as for >h
4043
4044
4045 RESPONSE
4046
4047 [http::]<Hs HTTP status code received from the next hop
4048 [http::]>Hs HTTP status code sent to the client
4049
4050 [http::]<h Reply header. Optional header name argument
4051 as for >h
4052
4053 [http::]mt MIME content type
4054
4055
4056 SIZE COUNTERS
4057
4058 [http::]st Total size of request + reply traffic with client
4059 [http::]>st Total size of request received from client.
4060 Excluding chunked encoding bytes.
4061 [http::]<st Total size of reply sent to client (after adaptation)
4062
4063 [http::]>sh Size of request headers received from client
4064 [http::]<sh Size of reply headers sent to client (after adaptation)
4065
4066 [http::]<sH Reply high offset sent
4067 [http::]<sS Upstream object size
4068
4069 [http::]<bs Number of HTTP-equivalent message body bytes
4070 received from the next hop, excluding chunked
4071 transfer encoding and control messages.
4072 Generated FTP/Gopher listings are treated as
4073 received bodies.
4074
4075
4076 TIMING
4077
4078 [http::]<pt Peer response time in milliseconds. The timer starts
4079 when the last request byte is sent to the next hop
4080 and stops when the last response byte is received.
4081 [http::]<tt Total time in milliseconds. The timer
4082 starts with the first connect request (or write I/O)
4083 sent to the first selected peer. The timer stops
4084 with the last I/O with the last peer.
4085
4086 Squid handling related format codes:
4087
4088 Ss Squid request status (TCP_MISS etc)
4089 Sh Squid hierarchy status (DEFAULT_PARENT etc)
4090
4091 SSL-related format codes:
4092
4093 ssl::bump_mode SslBump decision for the transaction:
4094
4095 For CONNECT requests that initiated bumping of
4096 a connection and for any request received on
4097 an already bumped connection, Squid logs the
4098 corresponding SslBump mode ("server-first" or
4099 "client-first"). See the ssl_bump option for
4100 more information about these modes.
4101
4102 A "none" token is logged for requests that
4103 triggered "ssl_bump" ACL evaluation matching
4104 either a "none" rule or no rules at all.
4105
4106 In all other cases, a single dash ("-") is
4107 logged.
4108
4109 ssl::>sni SSL client SNI sent to Squid. Available only
4110 after the peek, stare, or splice SSL bumping
4111 actions.
4112
4113 If ICAP is enabled, the following code becomes available (as
4114 well as ICAP log codes documented with the icap_log option):
4115
4116 icap::tt Total ICAP processing time for the HTTP
4117 transaction. The timer ticks when ICAP
4118 ACLs are checked and when ICAP
4119 transaction is in progress.
4120
4121 If adaptation is enabled the following three codes become available:
4122
4123 adapt::<last_h The header of the last ICAP response or
4124 meta-information from the last eCAP
4125 transaction related to the HTTP transaction.
4126 Like <h, accepts an optional header name
4127 argument.
4128
4129 adapt::sum_trs Summed adaptation transaction response
4130 times recorded as a comma-separated list in
4131 the order of transaction start time. Each time
4132 value is recorded as an integer number,
4133 representing response time of one or more
4134 adaptation (ICAP or eCAP) transaction in
4135 milliseconds. When a failed transaction is
4136 being retried or repeated, its time is not
4137 logged individually but added to the
4138 replacement (next) transaction. See also:
4139 adapt::all_trs.
4140
4141 adapt::all_trs All adaptation transaction response times.
4142 Same as adaptation_strs but response times of
4143 individual transactions are never added
4144 together. Instead, all transaction response
4145 times are recorded individually.
4146
4147 You can prefix adapt::*_trs format codes with adaptation
4148 service name in curly braces to record response time(s) specific
4149 to that service. For example: %{my_service}adapt::sum_trs
4150
4151 If SSL is enabled, the following formating codes become available:
4152
4153 %ssl::>cert_subject The Subject field of the received client
4154 SSL certificate or a dash ('-') if Squid has
4155 received an invalid/malformed certificate or
4156 no certificate at all. Consider encoding the
4157 logged value because Subject often has spaces.
4158
4159 %ssl::>cert_issuer The Issuer field of the received client
4160 SSL certificate or a dash ('-') if Squid has
4161 received an invalid/malformed certificate or
4162 no certificate at all. Consider encoding the
4163 logged value because Issuer often has spaces.
4164
4165 The default formats available (which do not need re-defining) are:
4166
4167logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
4168logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
4169logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
4170logformat referrer %ts.%03tu %>a %{Referer}>h %ru
4171logformat useragent %>a [%tl] "%{User-Agent}>h"
4172
4173 NOTE: When the log_mime_hdrs directive is set to ON.
4174 The squid, common and combined formats have a safely encoded copy
4175 of the mime headers appended to each line within a pair of brackets.
4176
4177 NOTE: The common and combined formats are not quite true to the Apache definition.
4178 The logs from Squid contain an extra status and hierarchy code appended.
4179
4180DOC_END
4181
4182NAME: access_log cache_access_log
4183TYPE: access_log
4184LOC: Config.Log.accesslogs
4185DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
4186DOC_START
4187 Configures whether and how Squid logs HTTP and ICP transactions.
4188 If access logging is enabled, a single line is logged for every
4189 matching HTTP or ICP request. The recommended directive formats are:
4190
4191 access_log <module>:<place> [option ...] [acl acl ...]
4192 access_log none [acl acl ...]
4193
4194 The following directive format is accepted but may be deprecated:
4195 access_log <module>:<place> [<logformat name> [acl acl ...]]
4196
4197 In most cases, the first ACL name must not contain the '=' character
4198 and should not be equal to an existing logformat name. You can always
4199 start with an 'all' ACL to work around those restrictions.
4200
4201 Will log to the specified module:place using the specified format (which
4202 must be defined in a logformat directive) those entries which match
4203 ALL the acl's specified (which must be defined in acl clauses).
4204 If no acl is specified, all requests will be logged to this destination.
4205
4206 ===== Available options for the recommended directive format =====
4207
4208 logformat=name Names log line format (either built-in or
4209 defined by a logformat directive). Defaults
4210 to 'squid'.
4211
4212 buffer-size=64KB Defines approximate buffering limit for log
4213 records (see buffered_logs). Squid should not
4214 keep more than the specified size and, hence,
4215 should flush records before the buffer becomes
4216 full to avoid overflows under normal
4217 conditions (the exact flushing algorithm is
4218 module-dependent though). The on-error option
4219 controls overflow handling.
4220
4221 on-error=die|drop Defines action on unrecoverable errors. The
4222 'drop' action ignores (i.e., does not log)
4223 affected log records. The default 'die' action
4224 kills the affected worker. The drop action
4225 support has not been tested for modules other
4226 than tcp.
4227
4228 ===== Modules Currently available =====
4229
4230 none Do not log any requests matching these ACL.
4231 Do not specify Place or logformat name.
4232
4233 stdio Write each log line to disk immediately at the completion of
4234 each request.
4235 Place: the filename and path to be written.
4236
4237 daemon Very similar to stdio. But instead of writing to disk the log
4238 line is passed to a daemon helper for asychronous handling instead.
4239 Place: varies depending on the daemon.
4240
4241 log_file_daemon Place: the file name and path to be written.
4242
4243 syslog To log each request via syslog facility.
4244 Place: The syslog facility and priority level for these entries.
4245 Place Format: facility.priority
4246
4247 where facility could be any of:
4248 authpriv, daemon, local0 ... local7 or user.
4249
4250 And priority could be any of:
4251 err, warning, notice, info, debug.
4252
4253 udp To send each log line as text data to a UDP receiver.
4254 Place: The destination host name or IP and port.
4255 Place Format: //host:port
4256
4257 tcp To send each log line as text data to a TCP receiver.
4258 Lines may be accumulated before sending (see buffered_logs).
4259 Place: The destination host name or IP and port.
4260 Place Format: //host:port
4261
4262 Default:
4263 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
4264DOC_END
4265
4266NAME: icap_log
4267TYPE: access_log
4268IFDEF: ICAP_CLIENT
4269LOC: Config.Log.icaplogs
4270DEFAULT: none
4271DOC_START
4272 ICAP log files record ICAP transaction summaries, one line per
4273 transaction.
4274
4275 The icap_log option format is:
4276 icap_log <filepath> [<logformat name> [acl acl ...]]
4277 icap_log none [acl acl ...]]
4278
4279 Please see access_log option documentation for details. The two
4280 kinds of logs share the overall configuration approach and many
4281 features.
4282
4283 ICAP processing of a single HTTP message or transaction may
4284 require multiple ICAP transactions. In such cases, multiple
4285 ICAP transaction log lines will correspond to a single access
4286 log line.
4287
4288 ICAP log uses logformat codes that make sense for an ICAP
4289 transaction. Header-related codes are applied to the HTTP header
4290 embedded in an ICAP server response, with the following caveats:
4291 For REQMOD, there is no HTTP response header unless the ICAP
4292 server performed request satisfaction. For RESPMOD, the HTTP
4293 request header is the header sent to the ICAP server. For
4294 OPTIONS, there are no HTTP headers.
4295
4296 The following format codes are also available for ICAP logs:
4297
4298 icap::<A ICAP server IP address. Similar to <A.
4299
4300 icap::<service_name ICAP service name from the icap_service
4301 option in Squid configuration file.
4302
4303 icap::ru ICAP Request-URI. Similar to ru.
4304
4305 icap::rm ICAP request method (REQMOD, RESPMOD, or
4306 OPTIONS). Similar to existing rm.
4307
4308 icap::>st Bytes sent to the ICAP server (TCP payload
4309 only; i.e., what Squid writes to the socket).
4310
4311 icap::<st Bytes received from the ICAP server (TCP
4312 payload only; i.e., what Squid reads from
4313 the socket).
4314
4315 icap::<bs Number of message body bytes received from the
4316 ICAP server. ICAP message body, if any, usually
4317 includes encapsulated HTTP message headers and
4318 possibly encapsulated HTTP message body. The
4319 HTTP body part is dechunked before its size is
4320 computed.
4321
4322 icap::tr Transaction response time (in
4323 milliseconds). The timer starts when
4324 the ICAP transaction is created and
4325 stops when the transaction is completed.
4326 Similar to tr.
4327
4328 icap::tio Transaction I/O time (in milliseconds). The
4329 timer starts when the first ICAP request
4330 byte is scheduled for sending. The timers
4331 stops when the last byte of the ICAP response
4332 is received.
4333
4334 icap::to Transaction outcome: ICAP_ERR* for all
4335 transaction errors, ICAP_OPT for OPTION
4336 transactions, ICAP_ECHO for 204
4337 responses, ICAP_MOD for message
4338 modification, and ICAP_SAT for request
4339 satisfaction. Similar to Ss.
4340
4341 icap::Hs ICAP response status code. Similar to Hs.
4342
4343 icap::>h ICAP request header(s). Similar to >h.
4344
4345 icap::<h ICAP response header(s). Similar to <h.
4346
4347 The default ICAP log format, which can be used without an explicit
4348 definition, is called icap_squid:
4349
4350logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
4351
4352 See also: logformat, log_icap, and %adapt::<last_h
4353DOC_END
4354
4355NAME: logfile_daemon
4356TYPE: string
4357DEFAULT: @DEFAULT_LOGFILED@
4358LOC: Log::TheConfig.logfile_daemon
4359DOC_START
4360 Specify the path to the logfile-writing daemon. This daemon is
4361 used to write the access and store logs, if configured.
4362
4363 Squid sends a number of commands to the log daemon:
4364 L<data>\n - logfile data
4365 R\n - rotate file
4366 T\n - truncate file
4367 O\n - reopen file
4368 F\n - flush file
4369 r<n>\n - set rotate count to <n>
4370 b<n>\n - 1 = buffer output, 0 = don't buffer output
4371
4372 No responses is expected.
4373DOC_END
4374
4375NAME: stats_collection
4376TYPE: acl_access
4377LOC: Config.accessList.stats_collection
4378DEFAULT: none
4379DEFAULT_DOC: Allow logging for all transactions.
4380COMMENT: allow|deny acl acl...
4381DOC_START
4382 This options allows you to control which requests gets accounted
4383 in performance counters.
4384
4385 This clause only supports fast acl types.
4386 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4387DOC_END
4388
4389NAME: cache_store_log
4390TYPE: string
4391DEFAULT: none
4392LOC: Config.Log.store
4393DOC_START
4394 Logs the activities of the storage manager. Shows which
4395 objects are ejected from the cache, and which objects are
4396 saved and for how long.
4397 There are not really utilities to analyze this data, so you can safely
4398 disable it (the default).
4399
4400 Store log uses modular logging outputs. See access_log for the list
4401 of modules supported.
4402
4403 Example:
4404 cache_store_log stdio:@DEFAULT_STORE_LOG@
4405 cache_store_log daemon:@DEFAULT_STORE_LOG@
4406DOC_END
4407
4408NAME: cache_swap_state cache_swap_log
4409TYPE: string
4410LOC: Config.Log.swap
4411DEFAULT: none
4412DEFAULT_DOC: Store the journal inside its cache_dir
4413DOC_START
4414 Location for the cache "swap.state" file. This index file holds
4415 the metadata of objects saved on disk. It is used to rebuild
4416 the cache during startup. Normally this file resides in each
4417 'cache_dir' directory, but you may specify an alternate
4418 pathname here. Note you must give a full filename, not just
4419 a directory. Since this is the index for the whole object
4420 list you CANNOT periodically rotate it!
4421
4422 If %s can be used in the file name it will be replaced with a
4423 a representation of the cache_dir name where each / is replaced
4424 with '.'. This is needed to allow adding/removing cache_dir
4425 lines when cache_swap_log is being used.
4426
4427 If have more than one 'cache_dir', and %s is not used in the name
4428 these swap logs will have names such as:
4429
4430 cache_swap_log.00
4431 cache_swap_log.01
4432 cache_swap_log.02
4433
4434 The numbered extension (which is added automatically)
4435 corresponds to the order of the 'cache_dir' lines in this
4436 configuration file. If you change the order of the 'cache_dir'
4437 lines in this file, these index files will NOT correspond to
4438 the correct 'cache_dir' entry (unless you manually rename
4439 them). We recommend you do NOT use this option. It is
4440 better to keep these index files in each 'cache_dir' directory.
4441DOC_END
4442
4443NAME: logfile_rotate
4444TYPE: int
4445DEFAULT: 10
4446LOC: Config.Log.rotateNumber
4447DOC_START
4448 Specifies the number of logfile rotations to make when you
4449 type 'squid -k rotate'. The default is 10, which will rotate
4450 with extensions 0 through 9. Setting logfile_rotate to 0 will
4451 disable the file name rotation, but the logfiles are still closed
4452 and re-opened. This will enable you to rename the logfiles
4453 yourself just before sending the rotate signal.
4454
4455 Note, the 'squid -k rotate' command normally sends a USR1
4456 signal to the running squid process. In certain situations
4457 (e.g. on Linux with Async I/O), USR1 is used for other
4458 purposes, so -k rotate uses another signal. It is best to get
4459 in the habit of using 'squid -k rotate' instead of 'kill -USR1
4460 <pid>'.
4461
4462 Note, from Squid-3.1 this option is only a default for cache.log,
4463 that log can be rotated separately by using debug_options.
4464DOC_END
4465
4466NAME: mime_table
4467TYPE: string
4468DEFAULT: @DEFAULT_MIME_TABLE@
4469LOC: Config.mimeTablePathname
4470DOC_START
4471 Path to Squid's icon configuration file.
4472
4473 You shouldn't need to change this, but the default file contains
4474 examples and formatting information if you do.
4475DOC_END
4476
4477NAME: log_mime_hdrs
4478COMMENT: on|off
4479TYPE: onoff
4480LOC: Config.onoff.log_mime_hdrs
4481DEFAULT: off
4482DOC_START
4483 The Cache can record both the request and the response MIME
4484 headers for each HTTP transaction. The headers are encoded
4485 safely and will appear as two bracketed fields at the end of
4486 the access log (for either the native or httpd-emulated log
4487 formats). To enable this logging set log_mime_hdrs to 'on'.
4488DOC_END
4489
4490NAME: pid_filename
4491TYPE: string
4492DEFAULT: @DEFAULT_PID_FILE@
4493LOC: Config.pidFilename
4494DOC_START
4495 A filename to write the process-id to. To disable, enter "none".
4496DOC_END
4497
4498NAME: client_netmask
4499TYPE: address
4500LOC: Config.Addrs.client_netmask
4501DEFAULT: no_addr
4502DEFAULT_DOC: Log full client IP address
4503DOC_START
4504 A netmask for client addresses in logfiles and cachemgr output.
4505 Change this to protect the privacy of your cache clients.
4506 A netmask of 255.255.255.0 will log all IP's in that range with
4507 the last digit set to '0'.
4508DOC_END
4509
4510NAME: strip_query_terms
4511TYPE: onoff
4512LOC: Config.onoff.strip_query_terms
4513DEFAULT: on
4514DOC_START
4515 By default, Squid strips query terms from requested URLs before
4516 logging. This protects your user's privacy and reduces log size.
4517
4518 When investigating HIT/MISS or other caching behaviour you
4519 will need to disable this to see the full URL used by Squid.
4520DOC_END
4521
4522NAME: buffered_logs
4523COMMENT: on|off
4524TYPE: onoff
4525DEFAULT: off
4526LOC: Config.onoff.buffered_logs
4527DOC_START
4528 Whether to write/send access_log records ASAP or accumulate them and
4529 then write/send them in larger chunks. Buffering may improve
4530 performance because it decreases the number of I/Os. However,
4531 buffering increases the delay before log records become available to
4532 the final recipient (e.g., a disk file or logging daemon) and,
4533 hence, increases the risk of log records loss.
4534
4535 Note that even when buffered_logs are off, Squid may have to buffer
4536 records if it cannot write/send them immediately due to pending I/Os
4537 (e.g., the I/O writing the previous log record) or connectivity loss.
4538
4539 Currently honored by 'daemon' and 'tcp' access_log modules only.
4540DOC_END
4541
4542NAME: netdb_filename
4543TYPE: string
4544DEFAULT: stdio:@DEFAULT_NETDB_FILE@
4545LOC: Config.netdbFilename
4546IFDEF: USE_ICMP
4547DOC_START
4548 Where Squid stores it's netdb journal.
4549 When enabled this journal preserves netdb state between restarts.
4550
4551 To disable, enter "none".
4552DOC_END
4553
4554COMMENT_START
4555 OPTIONS FOR TROUBLESHOOTING
4556 -----------------------------------------------------------------------------
4557COMMENT_END
4558
4559NAME: cache_log
4560TYPE: string
4561DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
4562LOC: Debug::cache_log
4563DOC_START
4564 Squid administrative logging file.
4565
4566 This is where general information about Squid behavior goes. You can
4567 increase the amount of data logged to this file and how often it is
4568 rotated with "debug_options"
4569DOC_END
4570
4571NAME: debug_options
4572TYPE: eol
4573DEFAULT: ALL,1
4574DEFAULT_DOC: Log all critical and important messages.
4575LOC: Debug::debugOptions
4576DOC_START
4577 Logging options are set as section,level where each source file
4578 is assigned a unique section. Lower levels result in less
4579 output, Full debugging (level 9) can result in a very large
4580 log file, so be careful.
4581
4582 The magic word "ALL" sets debugging levels for all sections.
4583 The default is to run with "ALL,1" to record important warnings.
4584
4585 The rotate=N option can be used to keep more or less of these logs
4586 than would otherwise be kept by logfile_rotate.
4587 For most uses a single log should be enough to monitor current
4588 events affecting Squid.
4589DOC_END
4590
4591NAME: coredump_dir
4592TYPE: string
4593LOC: Config.coredump_dir
4594DEFAULT_IF_NONE: none
4595DEFAULT_DOC: Use the directory from where Squid was started.
4596DOC_START
4597 By default Squid leaves core files in the directory from where
4598 it was started. If you set 'coredump_dir' to a directory
4599 that exists, Squid will chdir() to that directory at startup
4600 and coredump files will be left there.
4601
4602NOCOMMENT_START
4603
4604# Leave coredumps in the first cache dir
4605coredump_dir @DEFAULT_SWAP_DIR@
4606NOCOMMENT_END
4607DOC_END
4608
4609
4610COMMENT_START
4611 OPTIONS FOR FTP GATEWAYING
4612 -----------------------------------------------------------------------------
4613COMMENT_END
4614
4615NAME: ftp_user
4616TYPE: string
4617DEFAULT: Squid@
4618LOC: Config.Ftp.anon_user
4619DOC_START
4620 If you want the anonymous login password to be more informative
4621 (and enable the use of picky FTP servers), set this to something
4622 reasonable for your domain, like wwwuser@somewhere.net
4623
4624 The reason why this is domainless by default is the
4625 request can be made on the behalf of a user in any domain,
4626 depending on how the cache is used.
4627 Some FTP server also validate the email address is valid
4628 (for example perl.com).
4629DOC_END
4630
4631NAME: ftp_passive
4632TYPE: onoff
4633DEFAULT: on
4634LOC: Config.Ftp.passive
4635DOC_START
4636 If your firewall does not allow Squid to use passive
4637 connections, turn off this option.
4638
4639 Use of ftp_epsv_all option requires this to be ON.
4640DOC_END
4641
4642NAME: ftp_epsv_all
4643TYPE: onoff
4644DEFAULT: off
4645LOC: Config.Ftp.epsv_all
4646DOC_START
4647 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4648
4649 NATs may be able to put the connection on a "fast path" through the
4650 translator, as the EPRT command will never be used and therefore,
4651 translation of the data portion of the segments will never be needed.
4652
4653 When a client only expects to do two-way FTP transfers this may be
4654 useful.
4655 If squid finds that it must do a three-way FTP transfer after issuing
4656 an EPSV ALL command, the FTP session will fail.
4657
4658 If you have any doubts about this option do not use it.
4659 Squid will nicely attempt all other connection methods.
4660
4661 Requires ftp_passive to be ON (default) for any effect.
4662DOC_END
4663
4664NAME: ftp_epsv
4665TYPE: ftp_epsv
4666DEFAULT: none
4667LOC: Config.accessList.ftp_epsv
4668DOC_START
4669 FTP Protocol extensions permit the use of a special "EPSV" command.
4670
4671 NATs may be able to put the connection on a "fast path" through the
4672 translator using EPSV, as the EPRT command will never be used
4673 and therefore, translation of the data portion of the segments
4674 will never be needed.
4675
4676 EPSV is often required to interoperate with FTP servers on IPv6
4677 networks. On the other hand, it may break some IPv4 servers.
4678
4679 By default, EPSV may try EPSV with any FTP server. To fine tune
4680 that decision, you may restrict EPSV to certain clients or servers
4681 using ACLs:
4682
4683 ftp_epsv allow|deny al1 acl2 ...
4684
4685 WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
4686
4687 Only fast ACLs are supported.
4688 Requires ftp_passive to be ON (default) for any effect.
4689DOC_END
4690
4691NAME: ftp_eprt
4692TYPE: onoff
4693DEFAULT: on
4694LOC: Config.Ftp.eprt
4695DOC_START
4696 FTP Protocol extensions permit the use of a special "EPRT" command.
4697
4698 This extension provides a protocol neutral alternative to the
4699 IPv4-only PORT command. When supported it enables active FTP data
4700 channels over IPv6 and efficient NAT handling.
4701
4702 Turning this OFF will prevent EPRT being attempted and will skip
4703 straight to using PORT for IPv4 servers.
4704
4705 Some devices are known to not handle this extension correctly and
4706 may result in crashes. Devices which suport EPRT enough to fail
4707 cleanly will result in Squid attempting PORT anyway. This directive
4708 should only be disabled when EPRT results in device failures.
4709
4710 WARNING: Doing so will convert Squid back to the old behavior with all
4711 the related problems with external NAT devices/layers and IPv4-only FTP.
4712DOC_END
4713
4714NAME: ftp_sanitycheck
4715TYPE: onoff
4716DEFAULT: on
4717LOC: Config.Ftp.sanitycheck
4718DOC_START
4719 For security and data integrity reasons Squid by default performs
4720 sanity checks of the addresses of FTP data connections ensure the
4721 data connection is to the requested server. If you need to allow
4722 FTP connections to servers using another IP address for the data
4723 connection turn this off.
4724DOC_END
4725
4726NAME: ftp_telnet_protocol
4727TYPE: onoff
4728DEFAULT: on
4729LOC: Config.Ftp.telnet
4730DOC_START
4731 The FTP protocol is officially defined to use the telnet protocol
4732 as transport channel for the control connection. However, many
4733 implementations are broken and does not respect this aspect of
4734 the FTP protocol.
4735
4736 If you have trouble accessing files with ASCII code 255 in the
4737 path or similar problems involving this ASCII code you can
4738 try setting this directive to off. If that helps, report to the
4739 operator of the FTP server in question that their FTP server
4740 is broken and does not follow the FTP standard.
4741DOC_END
4742
4743COMMENT_START
4744 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4745 -----------------------------------------------------------------------------
4746COMMENT_END
4747
4748NAME: diskd_program
4749TYPE: string
4750DEFAULT: @DEFAULT_DISKD@
4751LOC: Config.Program.diskd
4752DOC_START
4753 Specify the location of the diskd executable.
4754 Note this is only useful if you have compiled in
4755 diskd as one of the store io modules.
4756DOC_END
4757
4758NAME: unlinkd_program
4759IFDEF: USE_UNLINKD
4760TYPE: string
4761DEFAULT: @DEFAULT_UNLINKD@
4762LOC: Config.Program.unlinkd
4763DOC_START
4764 Specify the location of the executable for file deletion process.
4765DOC_END
4766
4767NAME: pinger_program
4768TYPE: string
4769DEFAULT: @DEFAULT_PINGER@
4770LOC: Config.pinger.program
4771IFDEF: USE_ICMP
4772DOC_START
4773 Specify the location of the executable for the pinger process.
4774DOC_END
4775
4776NAME: pinger_enable
4777TYPE: onoff
4778DEFAULT: on
4779LOC: Config.pinger.enable
4780IFDEF: USE_ICMP
4781DOC_START
4782 Control whether the pinger is active at run-time.
4783 Enables turning ICMP pinger on and off with a simple
4784 squid -k reconfigure.
4785DOC_END
4786
4787
4788COMMENT_START
4789 OPTIONS FOR URL REWRITING
4790 -----------------------------------------------------------------------------
4791COMMENT_END
4792
4793NAME: url_rewrite_program redirect_program
4794TYPE: wordlist
4795LOC: Config.Program.redirect
4796DEFAULT: none
4797DOC_START
4798 Specify the location of the executable URL rewriter to use.
4799 Since they can perform almost any function there isn't one included.
4800
4801 For each requested URL, the rewriter will receive on line with the format
4802
4803 [channel-ID <SP>] URL [<SP> extras]<NL>
4804
4805 See url_rewrite_extras on how to send "extras" with optional values to
4806 the helper.
4807 After processing the request the helper must reply using the following format:
4808
4809 [channel-ID <SP>] result [<SP> kv-pairs]
4810
4811 The result code can be:
4812
4813 OK status=30N url="..."
4814 Redirect the URL to the one supplied in 'url='.
4815 'status=' is optional and contains the status code to send
4816 the client in Squids HTTP response. It must be one of the
4817 HTTP redirect status codes: 301, 302, 303, 307, 308.
4818 When no status is given Squid will use 302.
4819
4820 OK rewrite-url="..."
4821 Rewrite the URL to the one supplied in 'rewrite-url='.
4822 The new URL is fetched directly by Squid and returned to
4823 the client as the response to its request.
4824
4825 OK
4826 When neither of url= and rewrite-url= are sent Squid does
4827 not change the URL.
4828
4829 ERR
4830 Do not change the URL.
4831
4832 BH
4833 An internal error occurred in the helper, preventing
4834 a result being identified. The 'message=' key name is
4835 reserved for delivering a log message.
4836
4837
4838 In addition to the above kv-pairs Squid also understands the following
4839 optional kv-pairs received from URL rewriters:
4840 clt_conn_tag=TAG
4841 Associates a TAG with the client TCP connection.
4842 The TAG is treated as a regular annotation but persists across
4843 future requests on the client connection rather than just the
4844 current request. A helper may update the TAG during subsequent
4845 requests be returning a new kv-pair.
4846
4847 When using the concurrency= option the protocol is changed by
4848 introducing a query channel tag in front of the request/response.
4849 The query channel tag is a number between 0 and concurrency-1.
4850 This value must be echoed back unchanged to Squid as the first part
4851 of the response relating to its request.
4852
4853 WARNING: URL re-writing ability should be avoided whenever possible.
4854 Use the URL redirect form of response instead.
4855
4856 Re-write creates a difference in the state held by the client
4857 and server. Possibly causing confusion when the server response
4858 contains snippets of its view state. Embeded URLs, response
4859 and content Location headers, etc. are not re-written by this
4860 interface.
4861
4862 By default, a URL rewriter is not used.
4863DOC_END
4864
4865NAME: url_rewrite_children redirect_children
4866TYPE: HelperChildConfig
4867DEFAULT: 20 startup=0 idle=1 concurrency=0
4868LOC: Config.redirectChildren
4869DOC_START
4870 The maximum number of redirector processes to spawn. If you limit
4871 it too few Squid will have to wait for them to process a backlog of
4872 URLs, slowing it down. If you allow too many they will use RAM
4873 and other system resources noticably.
4874
4875 The startup= and idle= options allow some measure of skew in your
4876 tuning.
4877
4878 startup=
4879
4880 Sets a minimum of how many processes are to be spawned when Squid
4881 starts or reconfigures. When set to zero the first request will
4882 cause spawning of the first child process to handle it.
4883
4884 Starting too few will cause an initial slowdown in traffic as Squid
4885 attempts to simultaneously spawn enough processes to cope.
4886
4887 idle=
4888
4889 Sets a minimum of how many processes Squid is to try and keep available
4890 at all times. When traffic begins to rise above what the existing
4891 processes can handle this many more will be spawned up to the maximum
4892 configured. A minimum setting of 1 is required.
4893
4894 concurrency=
4895
4896 The number of requests each redirector helper can handle in
4897 parallel. Defaults to 0 which indicates the redirector
4898 is a old-style single threaded redirector.
4899
4900 When this directive is set to a value >= 1 then the protocol
4901 used to communicate with the helper is modified to include
4902 an ID in front of the request/response. The ID from the request
4903 must be echoed back with the response to that request.
4904
4905 queue-size=N
4906
4907 Sets the maximum number of queued requests.
4908 If the queued requests exceed queue size and redirector_bypass
4909 configuration option is set, then redirector is bypassed. Otherwise, if
4910 overloading persists squid may abort its operation.
4911 The default value is set to 2*numberofchildren.
4912DOC_END
4913
4914NAME: url_rewrite_host_header redirect_rewrites_host_header
4915TYPE: onoff
4916DEFAULT: on
4917LOC: Config.onoff.redir_rewrites_host
4918DOC_START
4919 To preserve same-origin security policies in browsers and
4920 prevent Host: header forgery by redirectors Squid rewrites
4921 any Host: header in redirected requests.
4922
4923 If you are running an accelerator this may not be a wanted
4924 effect of a redirector. This directive enables you disable
4925 Host: alteration in reverse-proxy traffic.
4926
4927 WARNING: Entries are cached on the result of the URL rewriting
4928 process, so be careful if you have domain-virtual hosts.
4929
4930 WARNING: Squid and other software verifies the URL and Host
4931 are matching, so be careful not to relay through other proxies
4932 or inspecting firewalls with this disabled.
4933DOC_END
4934
4935NAME: url_rewrite_access redirector_access
4936TYPE: acl_access
4937DEFAULT: none
4938DEFAULT_DOC: Allow, unless rules exist in squid.conf.
4939LOC: Config.accessList.redirector
4940DOC_START
4941 If defined, this access list specifies which requests are
4942 sent to the redirector processes.
4943
4944 This clause supports both fast and slow acl types.
4945 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4946DOC_END
4947
4948NAME: url_rewrite_bypass redirector_bypass
4949TYPE: onoff
4950LOC: Config.onoff.redirector_bypass
4951DEFAULT: off
4952DOC_START
4953 When this is 'on', a request will not go through the
4954 redirector if all the helpers are busy. If this is 'off'
4955 and the redirector queue grows too large, Squid will exit
4956 with a FATAL error and ask you to increase the number of
4957 redirectors. You should only enable this if the redirectors
4958 are not critical to your caching system. If you use
4959 redirectors for access control, and you enable this option,
4960 users may have access to pages they should not
4961 be allowed to request.
4962 This options sets default queue-size option of the url_rewrite_children
4963 to 0.
4964DOC_END
4965
4966NAME: url_rewrite_extras
4967TYPE: TokenOrQuotedString
4968LOC: Config.redirector_extras
4969DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
4970DOC_START
4971 Specifies a string to be append to request line format for the
4972 rewriter helper. "Quoted" format values may contain spaces and
4973 logformat %macros. In theory, any logformat %macro can be used.
4974 In practice, a %macro expands as a dash (-) if the helper request is
4975 sent before the required macro information is available to Squid.
4976DOC_END
4977
4978NAME: url_rewrite_timeout
4979TYPE: url_rewrite_timeout
4980LOC: Config
4981DEFAULT: none
4982DEFAULT_DOC: Squid waits for the helper response forever
4983DOC_START
4984 Squid times active requests to redirector. The timeout value and Squid
4985 reaction to a timed out request are configurable using the following
4986 format:
4987
4988 url_rewrite_timeout timeout time-units on_timeout=<action> [response=<quoted-response>]
4989
4990 supported timeout actions:
4991 fail Squid return a ERR_GATEWAY_FAILURE error page
4992
4993 bypass Do not re-write the URL
4994
4995 retry Send the lookup to the helper again
4996
4997 use_configured_response Use the <quoted-response> as
4998 helper response
4999DOC_END
5000
5001COMMENT_START
5002 OPTIONS FOR STORE ID
5003 -----------------------------------------------------------------------------
5004COMMENT_END
5005
5006NAME: store_id_program storeurl_rewrite_program
5007TYPE: wordlist
5008LOC: Config.Program.store_id
5009DEFAULT: none
5010DOC_START
5011 Specify the location of the executable StoreID helper to use.
5012 Since they can perform almost any function there isn't one included.
5013
5014 For each requested URL, the helper will receive one line with the format
5015
5016 [channel-ID <SP>] URL [<SP> extras]<NL>
5017
5018
5019 After processing the request the helper must reply using the following format:
5020
5021 [channel-ID <SP>] result [<SP> kv-pairs]
5022
5023 The result code can be:
5024
5025 OK store-id="..."
5026 Use the StoreID supplied in 'store-id='.
5027
5028 ERR
5029 The default is to use HTTP request URL as the store ID.
5030
5031 BH
5032 An internal error occured in the helper, preventing
5033 a result being identified.
5034
5035 In addition to the above kv-pairs Squid also understands the following
5036 optional kv-pairs received from URL rewriters:
5037 clt_conn_tag=TAG
5038 Associates a TAG with the client TCP connection.
5039 Please see url_rewrite_program related documentation for this
5040 kv-pair
5041
5042 Helper programs should be prepared to receive and possibly ignore
5043 additional whitespace-separated tokens on each input line.
5044
5045 When using the concurrency= option the protocol is changed by
5046 introducing a query channel tag in front of the request/response.
5047 The query channel tag is a number between 0 and concurrency-1.
5048 This value must be echoed back unchanged to Squid as the first part
5049 of the response relating to its request.
5050
5051 NOTE: when using StoreID refresh_pattern will apply to the StoreID
5052 returned from the helper and not the URL.
5053
5054 WARNING: Wrong StoreID value returned by a careless helper may result
5055 in the wrong cached response returned to the user.
5056
5057 By default, a StoreID helper is not used.
5058DOC_END
5059
5060NAME: store_id_extras
5061TYPE: TokenOrQuotedString
5062LOC: Config.storeId_extras
5063DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
5064DOC_START
5065 Specifies a string to be append to request line format for the
5066 StoreId helper. "Quoted" format values may contain spaces and
5067 logformat %macros. In theory, any logformat %macro can be used.
5068 In practice, a %macro expands as a dash (-) if the helper request is
5069 sent before the required macro information is available to Squid.
5070DOC_END
5071
5072NAME: store_id_children storeurl_rewrite_children
5073TYPE: HelperChildConfig
5074DEFAULT: 20 startup=0 idle=1 concurrency=0
5075LOC: Config.storeIdChildren
5076DOC_START
5077 The maximum number of StoreID helper processes to spawn. If you limit
5078 it too few Squid will have to wait for them to process a backlog of
5079 requests, slowing it down. If you allow too many they will use RAM
5080 and other system resources noticably.
5081
5082 The startup= and idle= options allow some measure of skew in your
5083 tuning.
5084
5085 startup=
5086
5087 Sets a minimum of how many processes are to be spawned when Squid
5088 starts or reconfigures. When set to zero the first request will
5089 cause spawning of the first child process to handle it.
5090
5091 Starting too few will cause an initial slowdown in traffic as Squid
5092 attempts to simultaneously spawn enough processes to cope.
5093
5094 idle=
5095
5096 Sets a minimum of how many processes Squid is to try and keep available
5097 at all times. When traffic begins to rise above what the existing
5098 processes can handle this many more will be spawned up to the maximum
5099 configured. A minimum setting of 1 is required.
5100
5101 concurrency=
5102
5103 The number of requests each storeID helper can handle in
5104 parallel. Defaults to 0 which indicates the helper
5105 is a old-style single threaded program.
5106
5107 When this directive is set to a value >= 1 then the protocol
5108 used to communicate with the helper is modified to include
5109 an ID in front of the request/response. The ID from the request
5110 must be echoed back with the response to that request.
5111
5112 queue-size=N
5113
5114 Sets the maximum number of queued requests.
5115 If the queued requests exceed queue size and store_id_bypass
5116 configuration option is set, then storeID helper is bypassed. Otherwise,
5117 if overloading persists squid may abort its operation.
5118 The default value is set to 2*numberofchildren.
5119DOC_END
5120
5121NAME: store_id_access storeurl_rewrite_access
5122TYPE: acl_access
5123DEFAULT: none
5124DEFAULT_DOC: Allow, unless rules exist in squid.conf.
5125LOC: Config.accessList.store_id
5126DOC_START
5127 If defined, this access list specifies which requests are
5128 sent to the StoreID processes. By default all requests
5129 are sent.
5130
5131 This clause supports both fast and slow acl types.
5132 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5133DOC_END
5134
5135NAME: store_id_bypass storeurl_rewrite_bypass
5136TYPE: onoff
5137LOC: Config.onoff.store_id_bypass
5138DEFAULT: on
5139DOC_START
5140 When this is 'on', a request will not go through the
5141 helper if all helpers are busy. If this is 'off'
5142 and the helper queue grows too large, Squid will exit
5143 with a FATAL error and ask you to increase the number of
5144 helpers. You should only enable this if the helperss
5145 are not critical to your caching system. If you use
5146 helpers for critical caching components, and you enable this
5147 option, users may not get objects from cache.
5148 This options sets default queue-size option of the store_id_children
5149 to 0.
5150DOC_END
5151
5152COMMENT_START
5153 OPTIONS FOR TUNING THE CACHE
5154 -----------------------------------------------------------------------------
5155COMMENT_END
5156
5157NAME: cache no_cache
5158TYPE: acl_access
5159DEFAULT: none
5160DEFAULT_DOC: By default, this directive is unused and has no effect.
5161LOC: Config.accessList.noCache
5162DOC_START
5163 Requests denied by this directive will not be served from the cache
5164 and their responses will not be stored in the cache. This directive
5165 has no effect on other transactions and on already cached responses.
5166
5167 This clause supports both fast and slow acl types.
5168 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5169
5170 This and the two other similar caching directives listed below are
5171 checked at different transaction processing stages, have different
5172 access to response information, affect different cache operations,
5173 and differ in slow ACLs support:
5174
5175 * cache: Checked before Squid makes a hit/miss determination.
5176 No access to reply information!
5177 Denies both serving a hit and storing a miss.
5178 Supports both fast and slow ACLs.
5179 * send_hit: Checked after a hit was detected.
5180 Has access to reply (hit) information.
5181 Denies serving a hit only.
5182 Supports fast ACLs only.
5183 * store_miss: Checked before storing a cachable miss.
5184 Has access to reply (miss) information.
5185 Denies storing a miss only.
5186 Supports fast ACLs only.
5187
5188 If you are not sure which of the three directives to use, apply the
5189 following decision logic:
5190
5191 * If your ACL(s) are of slow type _and_ need response info, redesign.
5192 Squid does not support that particular combination at this time.
5193 Otherwise:
5194 * If your directive ACL(s) are of slow type, use "cache"; and/or
5195 * if your directive ACL(s) need no response info, use "cache".
5196 Otherwise:
5197 * If you do not want the response cached, use store_miss; and/or
5198 * if you do not want a hit on a cached response, use send_hit.
5199DOC_END
5200
5201NAME: send_hit
5202TYPE: acl_access
5203DEFAULT: none
5204DEFAULT_DOC: By default, this directive is unused and has no effect.
5205LOC: Config.accessList.sendHit
5206DOC_START
5207 Responses denied by this directive will not be served from the cache
5208 (but may still be cached, see store_miss). This directive has no
5209 effect on the responses it allows and on the cached objects.
5210
5211 Please see the "cache" directive for a summary of differences among
5212 store_miss, send_hit, and cache directives.
5213
5214 Unlike the "cache" directive, send_hit only supports fast acl
5215 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5216
5217 For example:
5218
5219 # apply custom Store ID mapping to some URLs
5220 acl MapMe dstdomain .c.example.com
5221 store_id_program ...
5222 store_id_access allow MapMe
5223
5224 # but prevent caching of special responses
5225 # such as 302 redirects that cause StoreID loops
5226 acl Ordinary http_status 200-299
5227 store_miss deny MapMe !Ordinary
5228
5229 # and do not serve any previously stored special responses
5230 # from the cache (in case they were already cached before
5231 # the above store_miss rule was in effect).
5232 send_hit deny MapMe !Ordinary
5233DOC_END
5234
5235NAME: store_miss
5236TYPE: acl_access
5237DEFAULT: none
5238DEFAULT_DOC: By default, this directive is unused and has no effect.
5239LOC: Config.accessList.storeMiss
5240DOC_START
5241 Responses denied by this directive will not be cached (but may still
5242 be served from the cache, see send_hit). This directive has no
5243 effect on the responses it allows and on the already cached responses.
5244
5245 Please see the "cache" directive for a summary of differences among
5246 store_miss, send_hit, and cache directives. See the
5247 send_hit directive for a usage example.
5248
5249 Unlike the "cache" directive, store_miss only supports fast acl
5250 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5251DOC_END
5252
5253NAME: max_stale
5254COMMENT: time-units
5255TYPE: time_t
5256LOC: Config.maxStale
5257DEFAULT: 1 week
5258DOC_START
5259 This option puts an upper limit on how stale content Squid
5260 will serve from the cache if cache validation fails.
5261 Can be overriden by the refresh_pattern max-stale option.
5262DOC_END
5263
5264NAME: refresh_pattern
5265TYPE: refreshpattern
5266LOC: Config.Refresh
5267DEFAULT: none
5268DOC_START
5269 usage: refresh_pattern [-i] regex min percent max [options]
5270
5271 By default, regular expressions are CASE-SENSITIVE. To make
5272 them case-insensitive, use the -i option.
5273
5274 'Min' is the time (in minutes) an object without an explicit
5275 expiry time should be considered fresh. The recommended
5276 value is 0, any higher values may cause dynamic applications
5277 to be erroneously cached unless the application designer
5278 has taken the appropriate actions.
5279
5280 'Percent' is a percentage of the objects age (time since last
5281 modification age) an object without explicit expiry time
5282 will be considered fresh.
5283
5284 'Max' is an upper limit on how long objects without an explicit
5285 expiry time will be considered fresh.
5286
5287 options: override-expire
5288 override-lastmod
5289 reload-into-ims
5290 ignore-reload
5291 ignore-no-store
5292 ignore-must-revalidate
5293 ignore-private
5294 ignore-auth
5295 max-stale=NN
5296 refresh-ims
5297 store-stale
5298
5299 override-expire enforces min age even if the server
5300 sent an explicit expiry time (e.g., with the
5301 Expires: header or Cache-Control: max-age). Doing this
5302 VIOLATES the HTTP standard. Enabling this feature
5303 could make you liable for problems which it causes.
5304
5305 Note: override-expire does not enforce staleness - it only extends
5306 freshness / min. If the server returns a Expires time which
5307 is longer than your max time, Squid will still consider
5308 the object fresh for that period of time.
5309
5310 override-lastmod enforces min age even on objects
5311 that were modified recently.
5312
5313 reload-into-ims changes a client no-cache or ``reload''
5314 request for a cached entry into a conditional request using
5315 If-Modified-Since and/or If-None-Match headers, provided the
5316 cached entry has a Last-Modified and/or a strong ETag header.
5317 Doing this VIOLATES the HTTP standard. Enabling this feature
5318 could make you liable for problems which it causes.
5319
5320 ignore-reload ignores a client no-cache or ``reload''
5321 header. Doing this VIOLATES the HTTP standard. Enabling
5322 this feature could make you liable for problems which
5323 it causes.
5324
5325 ignore-no-store ignores any ``Cache-control: no-store''
5326 headers received from a server. Doing this VIOLATES
5327 the HTTP standard. Enabling this feature could make you
5328 liable for problems which it causes.
5329
5330 ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
5331 headers received from a server. Doing this VIOLATES
5332 the HTTP standard. Enabling this feature could make you
5333 liable for problems which it causes.
5334
5335 ignore-private ignores any ``Cache-control: private''
5336 headers received from a server. Doing this VIOLATES
5337 the HTTP standard. Enabling this feature could make you
5338 liable for problems which it causes.
5339
5340 ignore-auth caches responses to requests with authorization,
5341 as if the originserver had sent ``Cache-control: public''
5342 in the response header. Doing this VIOLATES the HTTP standard.
5343 Enabling this feature could make you liable for problems which
5344 it causes.
5345
5346 refresh-ims causes squid to contact the origin server
5347 when a client issues an If-Modified-Since request. This
5348 ensures that the client will receive an updated version
5349 if one is available.
5350
5351 store-stale stores responses even if they don't have explicit
5352 freshness or a validator (i.e., Last-Modified or an ETag)
5353 present, or if they're already stale. By default, Squid will
5354 not cache such responses because they usually can't be
5355 reused. Note that such responses will be stale by default.
5356
5357 max-stale=NN provide a maximum staleness factor. Squid won't
5358 serve objects more stale than this even if it failed to
5359 validate the object. Default: use the max_stale global limit.
5360
5361 Basically a cached object is:
5362
5363 FRESH if expires < now, else STALE
5364 STALE if age > max
5365 FRESH if lm-factor < percent, else STALE
5366 FRESH if age < min
5367 else STALE
5368
5369 The refresh_pattern lines are checked in the order listed here.
5370 The first entry which matches is used. If none of the entries
5371 match the default will be used.
5372
5373 Note, you must uncomment all the default lines if you want
5374 to change one. The default setting is only active if none is
5375 used.
5376
5377NOCOMMENT_START
5378
5379#
5380# Add any of your own refresh_pattern entries above these.
5381#
5382refresh_pattern ^ftp: 1440 20% 10080
5383refresh_pattern ^gopher: 1440 0% 1440
5384refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
5385refresh_pattern . 0 20% 4320
5386NOCOMMENT_END
5387DOC_END
5388
5389NAME: quick_abort_min
5390COMMENT: (KB)
5391TYPE: kb_int64_t
5392DEFAULT: 16 KB
5393LOC: Config.quickAbort.min
5394DOC_NONE
5395
5396NAME: quick_abort_max
5397COMMENT: (KB)
5398TYPE: kb_int64_t
5399DEFAULT: 16 KB
5400LOC: Config.quickAbort.max
5401DOC_NONE
5402
5403NAME: quick_abort_pct
5404COMMENT: (percent)
5405TYPE: int
5406DEFAULT: 95
5407LOC: Config.quickAbort.pct
5408DOC_START
5409 The cache by default continues downloading aborted requests
5410 which are almost completed (less than 16 KB remaining). This
5411 may be undesirable on slow (e.g. SLIP) links and/or very busy
5412 caches. Impatient users may tie up file descriptors and
5413 bandwidth by repeatedly requesting and immediately aborting
5414 downloads.
5415
5416 When the user aborts a request, Squid will check the
5417 quick_abort values to the amount of data transferred until
5418 then.
5419
5420 If the transfer has less than 'quick_abort_min' KB remaining,
5421 it will finish the retrieval.
5422
5423 If the transfer has more than 'quick_abort_max' KB remaining,
5424 it will abort the retrieval.
5425
5426 If more than 'quick_abort_pct' of the transfer has completed,
5427 it will finish the retrieval.
5428
5429 If you do not want any retrieval to continue after the client
5430 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
5431 to '0 KB'.
5432
5433 If you want retrievals to always continue if they are being
5434 cached set 'quick_abort_min' to '-1 KB'.
5435DOC_END
5436
5437NAME: read_ahead_gap
5438COMMENT: buffer-size
5439TYPE: b_int64_t
5440LOC: Config.readAheadGap
5441DEFAULT: 16 KB
5442DOC_START
5443 The amount of data the cache will buffer ahead of what has been
5444 sent to the client when retrieving an object from another server.
5445DOC_END
5446
5447NAME: negative_ttl
5448IFDEF: USE_HTTP_VIOLATIONS
5449COMMENT: time-units
5450TYPE: time_t
5451LOC: Config.negativeTtl
5452DEFAULT: 0 seconds
5453DOC_START
5454 Set the Default Time-to-Live (TTL) for failed requests.
5455 Certain types of failures (such as "connection refused" and
5456 "404 Not Found") are able to be negatively-cached for a short time.
5457 Modern web servers should provide Expires: header, however if they
5458 do not this can provide a minimum TTL.
5459 The default is not to cache errors with unknown expiry details.
5460
5461 Note that this is different from negative caching of DNS lookups.
5462
5463 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5464 this feature could make you liable for problems which it
5465 causes.
5466DOC_END
5467
5468NAME: positive_dns_ttl
5469COMMENT: time-units
5470TYPE: time_t
5471LOC: Config.positiveDnsTtl
5472DEFAULT: 6 hours
5473DOC_START
5474 Upper limit on how long Squid will cache positive DNS responses.
5475 Default is 6 hours (360 minutes). This directive must be set
5476 larger than negative_dns_ttl.
5477DOC_END
5478
5479NAME: negative_dns_ttl
5480COMMENT: time-units
5481TYPE: time_t
5482LOC: Config.negativeDnsTtl
5483DEFAULT: 1 minutes
5484DOC_START
5485 Time-to-Live (TTL) for negative caching of failed DNS lookups.
5486 This also sets the lower cache limit on positive lookups.
5487 Minimum value is 1 second, and it is not recommendable to go
5488 much below 10 seconds.
5489DOC_END
5490
5491NAME: range_offset_limit
5492COMMENT: size [acl acl...]
5493TYPE: acl_b_size_t
5494LOC: Config.rangeOffsetLimit
5495DEFAULT: none
5496DOC_START
5497 usage: (size) [units] [[!]aclname]
5498
5499 Sets an upper limit on how far (number of bytes) into the file
5500 a Range request may be to cause Squid to prefetch the whole file.
5501 If beyond this limit, Squid forwards the Range request as it is and
5502 the result is NOT cached.
5503
5504 This is to stop a far ahead range request (lets say start at 17MB)
5505 from making Squid fetch the whole object up to that point before
5506 sending anything to the client.
5507
5508 Multiple range_offset_limit lines may be specified, and they will
5509 be searched from top to bottom on each request until a match is found.
5510 The first match found will be used. If no line matches a request, the
5511 default limit of 0 bytes will be used.
5512
5513 'size' is the limit specified as a number of units.
5514
5515 'units' specifies whether to use bytes, KB, MB, etc.
5516 If no units are specified bytes are assumed.
5517
5518 A size of 0 causes Squid to never fetch more than the
5519 client requested. (default)
5520
5521 A size of 'none' causes Squid to always fetch the object from the
5522 beginning so it may cache the result. (2.0 style)
5523
5524 'aclname' is the name of a defined ACL.
5525
5526 NP: Using 'none' as the byte value here will override any quick_abort settings
5527 that may otherwise apply to the range request. The range request will
5528 be fully fetched from start to finish regardless of the client
5529 actions. This affects bandwidth usage.
5530DOC_END
5531
5532NAME: minimum_expiry_time
5533COMMENT: (seconds)
5534TYPE: time_t
5535LOC: Config.minimum_expiry_time
5536DEFAULT: 60 seconds
5537DOC_START
5538 The minimum caching time according to (Expires - Date)
5539 headers Squid honors if the object can't be revalidated.
5540 The default is 60 seconds.
5541
5542 In reverse proxy environments it might be desirable to honor
5543 shorter object lifetimes. It is most likely better to make
5544 your server return a meaningful Last-Modified header however.
5545
5546 In ESI environments where page fragments often have short
5547 lifetimes, this will often be best set to 0.
5548DOC_END
5549
5550NAME: store_avg_object_size
5551COMMENT: (bytes)
5552TYPE: b_int64_t
5553DEFAULT: 13 KB
5554LOC: Config.Store.avgObjectSize
5555DOC_START
5556 Average object size, used to estimate number of objects your
5557 cache can hold. The default is 13 KB.
5558
5559 This is used to pre-seed the cache index memory allocation to
5560 reduce expensive reallocate operations while handling clients
5561 traffic. Too-large values may result in memory allocation during
5562 peak traffic, too-small values will result in wasted memory.
5563
5564 Check the cache manager 'info' report metrics for the real
5565 object sizes seen by your Squid before tuning this.
5566DOC_END
5567
5568NAME: store_objects_per_bucket
5569TYPE: int
5570DEFAULT: 20
5571LOC: Config.Store.objectsPerBucket
5572DOC_START
5573 Target number of objects per bucket in the store hash table.
5574 Lowering this value increases the total number of buckets and
5575 also the storage maintenance rate. The default is 20.
5576DOC_END
5577
5578COMMENT_START
5579 HTTP OPTIONS
5580 -----------------------------------------------------------------------------
5581COMMENT_END
5582
5583NAME: request_header_max_size
5584COMMENT: (KB)
5585TYPE: b_size_t
5586DEFAULT: 64 KB
5587LOC: Config.maxRequestHeaderSize
5588DOC_START
5589 This specifies the maximum size for HTTP headers in a request.
5590 Request headers are usually relatively small (about 512 bytes).
5591 Placing a limit on the request header size will catch certain
5592 bugs (for example with persistent connections) and possibly
5593 buffer-overflow or denial-of-service attacks.
5594DOC_END
5595
5596NAME: reply_header_max_size
5597COMMENT: (KB)
5598TYPE: b_size_t
5599DEFAULT: 64 KB
5600LOC: Config.maxReplyHeaderSize
5601DOC_START
5602 This specifies the maximum size for HTTP headers in a reply.
5603 Reply headers are usually relatively small (about 512 bytes).
5604 Placing a limit on the reply header size will catch certain
5605 bugs (for example with persistent connections) and possibly
5606 buffer-overflow or denial-of-service attacks.
5607DOC_END
5608
5609NAME: request_body_max_size
5610COMMENT: (bytes)
5611TYPE: b_int64_t
5612DEFAULT: 0 KB
5613DEFAULT_DOC: No limit.
5614LOC: Config.maxRequestBodySize
5615DOC_START
5616 This specifies the maximum size for an HTTP request body.
5617 In other words, the maximum size of a PUT/POST request.
5618 A user who attempts to send a request with a body larger
5619 than this limit receives an "Invalid Request" error message.
5620 If you set this parameter to a zero (the default), there will
5621 be no limit imposed.
5622
5623 See also client_request_buffer_max_size for an alternative
5624 limitation on client uploads which can be configured.
5625DOC_END
5626
5627NAME: client_request_buffer_max_size
5628COMMENT: (bytes)
5629TYPE: b_size_t
5630DEFAULT: 512 KB
5631LOC: Config.maxRequestBufferSize
5632DOC_START
5633 This specifies the maximum buffer size of a client request.
5634 It prevents squid eating too much memory when somebody uploads
5635 a large file.
5636DOC_END
5637
5638NAME: chunked_request_body_max_size
5639COMMENT: (bytes)
5640TYPE: b_int64_t
5641DEFAULT: 64 KB
5642LOC: Config.maxChunkedRequestBodySize
5643DOC_START
5644 A broken or confused HTTP/1.1 client may send a chunked HTTP
5645 request to Squid. Squid does not have full support for that
5646 feature yet. To cope with such requests, Squid buffers the
5647 entire request and then dechunks request body to create a
5648 plain HTTP/1.0 request with a known content length. The plain
5649 request is then used by the rest of Squid code as usual.
5650
5651 The option value specifies the maximum size of the buffer used
5652 to hold the request before the conversion. If the chunked
5653 request size exceeds the specified limit, the conversion
5654 fails, and the client receives an "unsupported request" error,
5655 as if dechunking was disabled.
5656
5657 Dechunking is enabled by default. To disable conversion of
5658 chunked requests, set the maximum to zero.
5659
5660 Request dechunking feature and this option in particular are a
5661 temporary hack. When chunking requests and responses are fully
5662 supported, there will be no need to buffer a chunked request.
5663DOC_END
5664
5665NAME: broken_posts
5666IFDEF: USE_HTTP_VIOLATIONS
5667TYPE: acl_access
5668DEFAULT: none
5669DEFAULT_DOC: Obey RFC 2616.
5670LOC: Config.accessList.brokenPosts
5671DOC_START
5672 A list of ACL elements which, if matched, causes Squid to send
5673 an extra CRLF pair after the body of a PUT/POST request.
5674
5675 Some HTTP servers has broken implementations of PUT/POST,
5676 and rely on an extra CRLF pair sent by some WWW clients.
5677
5678 Quote from RFC2616 section 4.1 on this matter:
5679
5680 Note: certain buggy HTTP/1.0 client implementations generate an
5681 extra CRLF's after a POST request. To restate what is explicitly
5682 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5683 a request with an extra CRLF.
5684
5685 This clause only supports fast acl types.
5686 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5687
5688Example:
5689 acl buggy_server url_regex ^http://....
5690 broken_posts allow buggy_server
5691DOC_END
5692
5693NAME: adaptation_uses_indirect_client icap_uses_indirect_client
5694COMMENT: on|off
5695TYPE: onoff
5696IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
5697DEFAULT: on
5698LOC: Adaptation::Config::use_indirect_client
5699DOC_START
5700 Controls whether the indirect client IP address (instead of the direct
5701 client IP address) is passed to adaptation services.
5702
5703 See also: follow_x_forwarded_for adaptation_send_client_ip
5704DOC_END
5705
5706NAME: via
5707IFDEF: USE_HTTP_VIOLATIONS
5708COMMENT: on|off
5709TYPE: onoff
5710DEFAULT: on
5711LOC: Config.onoff.via
5712DOC_START
5713 If set (default), Squid will include a Via header in requests and
5714 replies as required by RFC2616.
5715DOC_END
5716
5717NAME: ie_refresh
5718COMMENT: on|off
5719TYPE: onoff
5720LOC: Config.onoff.ie_refresh
5721DEFAULT: off
5722DOC_START
5723 Microsoft Internet Explorer up until version 5.5 Service
5724 Pack 1 has an issue with transparent proxies, wherein it
5725 is impossible to force a refresh. Turning this on provides
5726 a partial fix to the problem, by causing all IMS-REFRESH
5727 requests from older IE versions to check the origin server
5728 for fresh content. This reduces hit ratio by some amount
5729 (~10% in my experience), but allows users to actually get
5730 fresh content when they want it. Note because Squid
5731 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
5732 of 5.5 is unchanged from old versions of Squid (i.e. a
5733 forced refresh is impossible). Newer versions of IE will,
5734 hopefully, continue to have the new behavior and will be
5735 handled based on that assumption. This option defaults to
5736 the old Squid behavior, which is better for hit ratios but
5737 worse for clients using IE, if they need to be able to
5738 force fresh content.
5739DOC_END
5740
5741NAME: vary_ignore_expire
5742COMMENT: on|off
5743TYPE: onoff
5744LOC: Config.onoff.vary_ignore_expire
5745DEFAULT: off
5746DOC_START
5747 Many HTTP servers supporting Vary gives such objects
5748 immediate expiry time with no cache-control header
5749 when requested by a HTTP/1.0 client. This option
5750 enables Squid to ignore such expiry times until
5751 HTTP/1.1 is fully implemented.
5752
5753 WARNING: If turned on this may eventually cause some
5754 varying objects not intended for caching to get cached.
5755DOC_END
5756
5757NAME: request_entities
5758TYPE: onoff
5759LOC: Config.onoff.request_entities
5760DEFAULT: off
5761DOC_START
5762 Squid defaults to deny GET and HEAD requests with request entities,
5763 as the meaning of such requests are undefined in the HTTP standard
5764 even if not explicitly forbidden.
5765
5766 Set this directive to on if you have clients which insists
5767 on sending request entities in GET or HEAD requests. But be warned
5768 that there is server software (both proxies and web servers) which
5769 can fail to properly process this kind of request which may make you
5770 vulnerable to cache pollution attacks if enabled.
5771DOC_END
5772
5773NAME: request_header_access
5774IFDEF: USE_HTTP_VIOLATIONS
5775TYPE: http_header_access
5776LOC: Config.request_header_access
5777DEFAULT: none
5778DEFAULT_DOC: No limits.
5779DOC_START
5780 Usage: request_header_access header_name allow|deny [!]aclname ...
5781
5782 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5783 this feature could make you liable for problems which it
5784 causes.
5785
5786 This option replaces the old 'anonymize_headers' and the
5787 older 'http_anonymizer' option with something that is much
5788 more configurable. A list of ACLs for each header name allows
5789 removal of specific header fields under specific conditions.
5790
5791 This option only applies to outgoing HTTP request headers (i.e.,
5792 headers sent by Squid to the next HTTP hop such as a cache peer
5793 or an origin server). The option has no effect during cache hit
5794 detection. The equivalent adaptation vectoring point in ICAP
5795 terminology is post-cache REQMOD.
5796
5797 The option is applied to individual outgoing request header
5798 fields. For each request header field F, Squid uses the first
5799 qualifying sets of request_header_access rules:
5800
5801 1. Rules with header_name equal to F's name.
5802 2. Rules with header_name 'Other', provided F's name is not
5803 on the hard-coded list of commonly used HTTP header names.
5804 3. Rules with header_name 'All'.
5805
5806 Within that qualifying rule set, rule ACLs are checked as usual.
5807 If ACLs of an "allow" rule match, the header field is allowed to
5808 go through as is. If ACLs of a "deny" rule match, the header is
5809 removed and request_header_replace is then checked to identify
5810 if the removed header has a replacement. If no rules within the
5811 set have matching ACLs, the header field is left as is.
5812
5813 For example, to achieve the same behavior as the old
5814 'http_anonymizer standard' option, you should use:
5815
5816 request_header_access From deny all
5817 request_header_access Referer deny all
5818 request_header_access User-Agent deny all
5819
5820 Or, to reproduce the old 'http_anonymizer paranoid' feature
5821 you should use:
5822
5823 request_header_access Authorization allow all
5824 request_header_access Proxy-Authorization allow all
5825 request_header_access Cache-Control allow all
5826 request_header_access Content-Length allow all
5827 request_header_access Content-Type allow all
5828 request_header_access Date allow all
5829 request_header_access Host allow all
5830 request_header_access If-Modified-Since allow all
5831 request_header_access Pragma allow all
5832 request_header_access Accept allow all
5833 request_header_access Accept-Charset allow all
5834 request_header_access Accept-Encoding allow all
5835 request_header_access Accept-Language allow all
5836 request_header_access Connection allow all
5837 request_header_access All deny all
5838
5839 HTTP reply headers are controlled with the reply_header_access directive.
5840
5841 By default, all headers are allowed (no anonymizing is performed).
5842DOC_END
5843
5844NAME: reply_header_access
5845IFDEF: USE_HTTP_VIOLATIONS
5846TYPE: http_header_access
5847LOC: Config.reply_header_access
5848DEFAULT: none
5849DEFAULT_DOC: No limits.
5850DOC_START
5851 Usage: reply_header_access header_name allow|deny [!]aclname ...
5852
5853 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5854 this feature could make you liable for problems which it
5855 causes.
5856
5857 This option only applies to reply headers, i.e., from the
5858 server to the client.
5859
5860 This is the same as request_header_access, but in the other
5861 direction. Please see request_header_access for detailed
5862 documentation.
5863
5864 For example, to achieve the same behavior as the old
5865 'http_anonymizer standard' option, you should use:
5866
5867 reply_header_access Server deny all
5868 reply_header_access WWW-Authenticate deny all
5869 reply_header_access Link deny all
5870
5871 Or, to reproduce the old 'http_anonymizer paranoid' feature
5872 you should use:
5873
5874 reply_header_access Allow allow all
5875 reply_header_access WWW-Authenticate allow all
5876 reply_header_access Proxy-Authenticate allow all
5877 reply_header_access Cache-Control allow all
5878 reply_header_access Content-Encoding allow all
5879 reply_header_access Content-Length allow all
5880 reply_header_access Content-Type allow all
5881 reply_header_access Date allow all
5882 reply_header_access Expires allow all
5883 reply_header_access Last-Modified allow all
5884 reply_header_access Location allow all
5885 reply_header_access Pragma allow all
5886 reply_header_access Content-Language allow all
5887 reply_header_access Retry-After allow all
5888 reply_header_access Title allow all
5889 reply_header_access Content-Disposition allow all
5890 reply_header_access Connection allow all
5891 reply_header_access All deny all
5892
5893 HTTP request headers are controlled with the request_header_access directive.
5894
5895 By default, all headers are allowed (no anonymizing is
5896 performed).
5897DOC_END
5898
5899NAME: request_header_replace header_replace
5900IFDEF: USE_HTTP_VIOLATIONS
5901TYPE: http_header_replace
5902LOC: Config.request_header_access
5903DEFAULT: none
5904DOC_START
5905 Usage: request_header_replace header_name message
5906 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5907
5908 This option allows you to change the contents of headers
5909 denied with request_header_access above, by replacing them
5910 with some fixed string.
5911
5912 This only applies to request headers, not reply headers.
5913
5914 By default, headers are removed if denied.
5915DOC_END
5916
5917NAME: reply_header_replace
5918IFDEF: USE_HTTP_VIOLATIONS
5919TYPE: http_header_replace
5920LOC: Config.reply_header_access
5921DEFAULT: none
5922DOC_START
5923 Usage: reply_header_replace header_name message
5924 Example: reply_header_replace Server Foo/1.0
5925
5926 This option allows you to change the contents of headers
5927 denied with reply_header_access above, by replacing them
5928 with some fixed string.
5929
5930 This only applies to reply headers, not request headers.
5931
5932 By default, headers are removed if denied.
5933DOC_END
5934
5935NAME: request_header_add
5936TYPE: HeaderWithAclList
5937LOC: Config.request_header_add
5938DEFAULT: none
5939DOC_START
5940 Usage: request_header_add field-name field-value acl1 [acl2] ...
5941 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5942
5943 This option adds header fields to outgoing HTTP requests (i.e.,
5944 request headers sent by Squid to the next HTTP hop such as a
5945 cache peer or an origin server). The option has no effect during
5946 cache hit detection. The equivalent adaptation vectoring point
5947 in ICAP terminology is post-cache REQMOD.
5948
5949 Field-name is a token specifying an HTTP header name. If a
5950 standard HTTP header name is used, Squid does not check whether
5951 the new header conflicts with any existing headers or violates
5952 HTTP rules. If the request to be modified already contains a
5953 field with the same name, the old field is preserved but the
5954 header field values are not merged.
5955
5956 Field-value is either a token or a quoted string. If quoted
5957 string format is used, then the surrounding quotes are removed
5958 while escape sequences and %macros are processed.
5959
5960 In theory, all of the logformat codes can be used as %macros.
5961 However, unlike logging (which happens at the very end of
5962 transaction lifetime), the transaction may not yet have enough
5963 information to expand a macro when the new header value is needed.
5964 And some information may already be available to Squid but not yet
5965 committed where the macro expansion code can access it (report
5966 such instances!). The macro will be expanded into a single dash
5967 ('-') in such cases. Not all macros have been tested.
5968
5969 One or more Squid ACLs may be specified to restrict header
5970 injection to matching requests. As always in squid.conf, all
5971 ACLs in an option ACL list must be satisfied for the insertion
5972 to happen. The request_header_add option supports fast ACLs
5973 only.
5974DOC_END
5975
5976NAME: note
5977TYPE: note
5978LOC: Config.notes
5979DEFAULT: none
5980DOC_START
5981 This option used to log custom information about the master
5982 transaction. For example, an admin may configure Squid to log
5983 which "user group" the transaction belongs to, where "user group"
5984 will be determined based on a set of ACLs and not [just]
5985 authentication information.
5986 Values of key/value pairs can be logged using %{key}note macros:
5987
5988 note key value acl ...
5989 logformat myFormat ... %{key}note ...
5990DOC_END
5991
5992NAME: relaxed_header_parser
5993COMMENT: on|off|warn
5994TYPE: tristate
5995LOC: Config.onoff.relaxed_header_parser
5996DEFAULT: on
5997DOC_START
5998 In the default "on" setting Squid accepts certain forms
5999 of non-compliant HTTP messages where it is unambiguous
6000 what the sending application intended even if the message
6001 is not correctly formatted. The messages is then normalized
6002 to the correct form when forwarded by Squid.
6003
6004 If set to "warn" then a warning will be emitted in cache.log
6005 each time such HTTP error is encountered.
6006
6007 If set to "off" then such HTTP errors will cause the request
6008 or response to be rejected.
6009DOC_END
6010
6011NAME: collapsed_forwarding
6012COMMENT: (on|off)
6013TYPE: onoff
6014LOC: Config.onoff.collapsed_forwarding
6015DEFAULT: off
6016DOC_START
6017 This option controls whether Squid is allowed to merge multiple
6018 potentially cachable requests for the same URI before Squid knows
6019 whether the response is going to be cachable.
6020
6021 This feature is disabled by default: Enabling collapsed forwarding
6022 needlessly delays forwarding requests that look cachable (when they are
6023 collapsed) but then need to be forwarded individually anyway because
6024 they end up being for uncachable content. However, in some cases, such
6025 as accelleration of highly cachable content with periodic or groupped
6026 expiration times, the gains from collapsing [large volumes of
6027 simultenous refresh requests] outweigh losses from such delays.
6028DOC_END
6029
6030COMMENT_START
6031 TIMEOUTS
6032 -----------------------------------------------------------------------------
6033COMMENT_END
6034
6035NAME: forward_timeout
6036COMMENT: time-units
6037TYPE: time_t
6038LOC: Config.Timeout.forward
6039DEFAULT: 4 minutes
6040DOC_START
6041 This parameter specifies how long Squid should at most attempt in
6042 finding a forwarding path for the request before giving up.
6043DOC_END
6044
6045NAME: connect_timeout
6046COMMENT: time-units
6047TYPE: time_t
6048LOC: Config.Timeout.connect
6049DEFAULT: 1 minute
6050DOC_START
6051 This parameter specifies how long to wait for the TCP connect to
6052 the requested server or peer to complete before Squid should
6053 attempt to find another path where to forward the request.
6054DOC_END
6055
6056NAME: peer_connect_timeout
6057COMMENT: time-units
6058TYPE: time_t
6059LOC: Config.Timeout.peer_connect
6060DEFAULT: 30 seconds
6061DOC_START
6062 This parameter specifies how long to wait for a pending TCP
6063 connection to a peer cache. The default is 30 seconds. You
6064 may also set different timeout values for individual neighbors
6065 with the 'connect-timeout' option on a 'cache_peer' line.
6066DOC_END
6067
6068NAME: read_timeout
6069COMMENT: time-units
6070TYPE: time_t
6071LOC: Config.Timeout.read
6072DEFAULT: 15 minutes
6073DOC_START
6074 Applied on peer server connections.
6075
6076 After each successful read(), the timeout will be extended by this
6077 amount. If no data is read again after this amount of time,
6078 the request is aborted and logged with ERR_READ_TIMEOUT.
6079
6080 The default is 15 minutes.
6081DOC_END
6082
6083NAME: write_timeout
6084COMMENT: time-units
6085TYPE: time_t
6086LOC: Config.Timeout.write
6087DEFAULT: 15 minutes
6088DOC_START
6089 This timeout is tracked for all connections that have data
6090 available for writing and are waiting for the socket to become
6091 ready. After each successful write, the timeout is extended by
6092 the configured amount. If Squid has data to write but the
6093 connection is not ready for the configured duration, the
6094 transaction associated with the connection is terminated. The
6095 default is 15 minutes.
6096DOC_END
6097
6098NAME: request_timeout
6099TYPE: time_t
6100LOC: Config.Timeout.request
6101DEFAULT: 5 minutes
6102DOC_START
6103 How long to wait for complete HTTP request headers after initial
6104 connection establishment.
6105DOC_END
6106
6107NAME: client_idle_pconn_timeout persistent_request_timeout
6108TYPE: time_t
6109LOC: Config.Timeout.clientIdlePconn
6110DEFAULT: 2 minutes
6111DOC_START
6112 How long to wait for the next HTTP request on a persistent
6113 client connection after the previous request completes.
6114DOC_END
6115
6116NAME: ftp_client_idle_timeout
6117TYPE: time_t
6118LOC: Config.Timeout.ftpClientIdle
6119DEFAULT: 30 minutes
6120DOC_START
6121 How long to wait for an FTP request on a connection to Squid ftp_port.
6122 Many FTP clients do not deal with idle connection closures well,
6123 necessitating a longer default timeout than client_idle_pconn_timeout
6124 used for incoming HTTP requests.
6125DOC_END
6126
6127NAME: client_lifetime
6128COMMENT: time-units
6129TYPE: time_t
6130LOC: Config.Timeout.lifetime
6131DEFAULT: 1 day
6132DOC_START
6133 The maximum amount of time a client (browser) is allowed to
6134 remain connected to the cache process. This protects the Cache
6135 from having a lot of sockets (and hence file descriptors) tied up
6136 in a CLOSE_WAIT state from remote clients that go away without
6137 properly shutting down (either because of a network failure or
6138 because of a poor client implementation). The default is one
6139 day, 1440 minutes.
6140
6141 NOTE: The default value is intended to be much larger than any
6142 client would ever need to be connected to your cache. You
6143 should probably change client_lifetime only as a last resort.
6144 If you seem to have many client connections tying up
6145 filedescriptors, we recommend first tuning the read_timeout,
6146 request_timeout, persistent_request_timeout and quick_abort values.
6147DOC_END
6148
6149NAME: pconn_lifetime
6150COMMENT: time-units
6151TYPE: time_t
6152LOC: Config.Timeout.pconnLifetime
6153DEFAULT: 0 seconds
6154DOC_START
6155 Desired maximum lifetime of a persistent connection.
6156 When set, Squid will close a now-idle persistent connection that
6157 exceeded configured lifetime instead of moving the connection into
6158 the idle connection pool (or equivalent). No effect on ongoing/active
6159 transactions. Connection lifetime is the time period from the
6160 connection acceptance or opening time until "now".
6161
6162 This limit is useful in environments with long-lived connections
6163 where Squid configuration or environmental factors change during a
6164 single connection lifetime. If unrestricted, some connections may
6165 last for hours and even days, ignoring those changes that should
6166 have affected their behavior or their existence.
6167
6168 Currently, a new lifetime value supplied via Squid reconfiguration
6169 has no effect on already idle connections unless they become busy.
6170
6171 When set to '0' this limit is not used.
6172DOC_END
6173
6174NAME: half_closed_clients
6175TYPE: onoff
6176LOC: Config.onoff.half_closed_clients
6177DEFAULT: off
6178DOC_START
6179 Some clients may shutdown the sending side of their TCP
6180 connections, while leaving their receiving sides open. Sometimes,
6181 Squid can not tell the difference between a half-closed and a
6182 fully-closed TCP connection.
6183
6184 By default, Squid will immediately close client connections when
6185 read(2) returns "no more data to read."
6186
6187 Change this option to 'on' and Squid will keep open connections
6188 until a read(2) or write(2) on the socket returns an error.
6189 This may show some benefits for reverse proxies. But if not
6190 it is recommended to leave OFF.
6191DOC_END
6192
6193NAME: server_idle_pconn_timeout pconn_timeout
6194TYPE: time_t
6195LOC: Config.Timeout.serverIdlePconn
6196DEFAULT: 1 minute
6197DOC_START
6198 Timeout for idle persistent connections to servers and other
6199 proxies.
6200DOC_END
6201
6202NAME: ident_timeout
6203TYPE: time_t
6204IFDEF: USE_IDENT
6205LOC: Ident::TheConfig.timeout
6206DEFAULT: 10 seconds
6207DOC_START
6208 Maximum time to wait for IDENT lookups to complete.
6209
6210 If this is too high, and you enabled IDENT lookups from untrusted
6211 users, you might be susceptible to denial-of-service by having
6212 many ident requests going at once.
6213DOC_END
6214
6215NAME: shutdown_lifetime
6216COMMENT: time-units
6217TYPE: time_t
6218LOC: Config.shutdownLifetime
6219DEFAULT: 30 seconds
6220DOC_START
6221 When SIGTERM or SIGHUP is received, the cache is put into
6222 "shutdown pending" mode until all active sockets are closed.
6223 This value is the lifetime to set for all open descriptors
6224 during shutdown mode. Any active clients after this many
6225 seconds will receive a 'timeout' message.
6226DOC_END
6227
6228COMMENT_START
6229 ADMINISTRATIVE PARAMETERS
6230 -----------------------------------------------------------------------------
6231COMMENT_END
6232
6233NAME: cache_mgr
6234TYPE: string
6235DEFAULT: webmaster
6236LOC: Config.adminEmail
6237DOC_START
6238 Email-address of local cache manager who will receive
6239 mail if the cache dies. The default is "webmaster".
6240DOC_END
6241
6242NAME: mail_from
6243TYPE: string
6244DEFAULT: none
6245LOC: Config.EmailFrom
6246DOC_START
6247 From: email-address for mail sent when the cache dies.
6248 The default is to use 'squid@unique_hostname'.
6249
6250 See also: unique_hostname directive.
6251DOC_END
6252
6253NAME: mail_program
6254TYPE: eol
6255DEFAULT: mail
6256LOC: Config.EmailProgram
6257DOC_START
6258 Email program used to send mail if the cache dies.
6259 The default is "mail". The specified program must comply
6260 with the standard Unix mail syntax:
6261 mail-program recipient < mailfile
6262
6263 Optional command line options can be specified.
6264DOC_END
6265
6266NAME: cache_effective_user
6267TYPE: string
6268DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
6269LOC: Config.effectiveUser
6270DOC_START
6271 If you start Squid as root, it will change its effective/real
6272 UID/GID to the user specified below. The default is to change
6273 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
6274 see also; cache_effective_group
6275DOC_END
6276
6277NAME: cache_effective_group
6278TYPE: string
6279DEFAULT: none
6280DEFAULT_DOC: Use system group memberships of the cache_effective_user account
6281LOC: Config.effectiveGroup
6282DOC_START
6283 Squid sets the GID to the effective user's default group ID
6284 (taken from the password file) and supplementary group list
6285 from the groups membership.
6286
6287 If you want Squid to run with a specific GID regardless of
6288 the group memberships of the effective user then set this
6289 to the group (or GID) you want Squid to run as. When set
6290 all other group privileges of the effective user are ignored
6291 and only this GID is effective. If Squid is not started as
6292 root the user starting Squid MUST be member of the specified
6293 group.
6294
6295 This option is not recommended by the Squid Team.
6296 Our preference is for administrators to configure a secure
6297 user account for squid with UID/GID matching system policies.
6298DOC_END
6299
6300NAME: httpd_suppress_version_string
6301COMMENT: on|off
6302TYPE: onoff
6303DEFAULT: off
6304LOC: Config.onoff.httpd_suppress_version_string
6305DOC_START
6306 Suppress Squid version string info in HTTP headers and HTML error pages.
6307DOC_END
6308
6309NAME: visible_hostname
6310TYPE: string
6311LOC: Config.visibleHostname
6312DEFAULT: none
6313DEFAULT_DOC: Automatically detect the system host name
6314DOC_START
6315 If you want to present a special hostname in error messages, etc,
6316 define this. Otherwise, the return value of gethostname()
6317 will be used. If you have multiple caches in a cluster and
6318 get errors about IP-forwarding you must set them to have individual
6319 names with this setting.
6320DOC_END
6321
6322NAME: unique_hostname
6323TYPE: string
6324LOC: Config.uniqueHostname
6325DEFAULT: none
6326DEFAULT_DOC: Copy the value from visible_hostname
6327DOC_START
6328 If you want to have multiple machines with the same
6329 'visible_hostname' you must give each machine a different
6330 'unique_hostname' so forwarding loops can be detected.
6331DOC_END
6332
6333NAME: hostname_aliases
6334TYPE: wordlist
6335LOC: Config.hostnameAliases
6336DEFAULT: none
6337DOC_START
6338 A list of other DNS names your cache has.
6339DOC_END
6340
6341NAME: umask
6342TYPE: int
6343LOC: Config.umask
6344DEFAULT: 027
6345DOC_START
6346 Minimum umask which should be enforced while the proxy
6347 is running, in addition to the umask set at startup.
6348
6349 For a traditional octal representation of umasks, start
6350 your value with 0.
6351DOC_END
6352
6353COMMENT_START
6354 OPTIONS FOR THE CACHE REGISTRATION SERVICE
6355 -----------------------------------------------------------------------------
6356
6357 This section contains parameters for the (optional) cache
6358 announcement service. This service is provided to help
6359 cache administrators locate one another in order to join or
6360 create cache hierarchies.
6361
6362 An 'announcement' message is sent (via UDP) to the registration
6363 service by Squid. By default, the announcement message is NOT
6364 SENT unless you enable it with 'announce_period' below.
6365
6366 The announcement message includes your hostname, plus the
6367 following information from this configuration file:
6368
6369 http_port
6370 icp_port
6371 cache_mgr
6372
6373 All current information is processed regularly and made
6374 available on the Web at http://www.ircache.net/Cache/Tracker/.
6375COMMENT_END
6376
6377NAME: announce_period
6378TYPE: time_t
6379LOC: Config.Announce.period
6380DEFAULT: 0
6381DEFAULT_DOC: Announcement messages disabled.
6382DOC_START
6383 This is how frequently to send cache announcements.
6384
6385 To enable announcing your cache, just set an announce period.
6386
6387 Example:
6388 announce_period 1 day
6389DOC_END
6390
6391NAME: announce_host
6392TYPE: string
6393DEFAULT: tracker.ircache.net
6394LOC: Config.Announce.host
6395DOC_START
6396 Set the hostname where announce registration messages will be sent.
6397
6398 See also announce_port and announce_file
6399DOC_END
6400
6401NAME: announce_file
6402TYPE: string
6403DEFAULT: none
6404LOC: Config.Announce.file
6405DOC_START
6406 The contents of this file will be included in the announce
6407 registration messages.
6408DOC_END
6409
6410NAME: announce_port
6411TYPE: u_short
6412DEFAULT: 3131
6413LOC: Config.Announce.port
6414DOC_START
6415 Set the port where announce registration messages will be sent.
6416
6417 See also announce_host and announce_file
6418DOC_END
6419
6420COMMENT_START
6421 HTTPD-ACCELERATOR OPTIONS
6422 -----------------------------------------------------------------------------
6423COMMENT_END
6424
6425NAME: httpd_accel_surrogate_id
6426TYPE: string
6427DEFAULT: none
6428DEFAULT_DOC: visible_hostname is used if no specific ID is set.
6429LOC: Config.Accel.surrogate_id
6430DOC_START
6431 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
6432 need an identification token to allow control targeting. Because
6433 a farm of surrogates may all perform the same tasks, they may share
6434 an identification token.
6435DOC_END
6436
6437NAME: http_accel_surrogate_remote
6438COMMENT: on|off
6439TYPE: onoff
6440DEFAULT: off
6441LOC: Config.onoff.surrogate_is_remote
6442DOC_START
6443 Remote surrogates (such as those in a CDN) honour the header
6444 "Surrogate-Control: no-store-remote".
6445
6446 Set this to on to have squid behave as a remote surrogate.
6447DOC_END
6448
6449NAME: esi_parser
6450IFDEF: USE_SQUID_ESI
6451COMMENT: libxml2|expat|custom
6452TYPE: string
6453LOC: ESIParser::Type
6454DEFAULT: custom
6455DOC_START
6456 ESI markup is not strictly XML compatible. The custom ESI parser
6457 will give higher performance, but cannot handle non ASCII character
6458 encodings.
6459DOC_END
6460
6461COMMENT_START
6462 DELAY POOL PARAMETERS
6463 -----------------------------------------------------------------------------
6464COMMENT_END
6465
6466NAME: delay_pools
6467TYPE: delay_pool_count
6468DEFAULT: 0
6469IFDEF: USE_DELAY_POOLS
6470LOC: Config.Delay
6471DOC_START
6472 This represents the number of delay pools to be used. For example,
6473 if you have one class 2 delay pool and one class 3 delays pool, you
6474 have a total of 2 delay pools.
6475
6476 See also delay_parameters, delay_class, delay_access for pool
6477 configuration details.
6478DOC_END
6479
6480NAME: delay_class
6481TYPE: delay_pool_class
6482DEFAULT: none
6483IFDEF: USE_DELAY_POOLS
6484LOC: Config.Delay
6485DOC_START
6486 This defines the class of each delay pool. There must be exactly one
6487 delay_class line for each delay pool. For example, to define two
6488 delay pools, one of class 2 and one of class 3, the settings above
6489 and here would be:
6490
6491 Example:
6492 delay_pools 4 # 4 delay pools
6493 delay_class 1 2 # pool 1 is a class 2 pool
6494 delay_class 2 3 # pool 2 is a class 3 pool
6495 delay_class 3 4 # pool 3 is a class 4 pool
6496 delay_class 4 5 # pool 4 is a class 5 pool
6497
6498 The delay pool classes are:
6499
6500 class 1 Everything is limited by a single aggregate
6501 bucket.
6502
6503 class 2 Everything is limited by a single aggregate
6504 bucket as well as an "individual" bucket chosen
6505 from bits 25 through 32 of the IPv4 address.
6506
6507 class 3 Everything is limited by a single aggregate
6508 bucket as well as a "network" bucket chosen
6509 from bits 17 through 24 of the IP address and a
6510 "individual" bucket chosen from bits 17 through
6511 32 of the IPv4 address.
6512
6513 class 4 Everything in a class 3 delay pool, with an
6514 additional limit on a per user basis. This
6515 only takes effect if the username is established
6516 in advance - by forcing authentication in your
6517 http_access rules.
6518
6519 class 5 Requests are grouped according their tag (see
6520 external_acl's tag= reply).
6521
6522
6523 Each pool also requires a delay_parameters directive to configure the pool size
6524 and speed limits used whenever the pool is applied to a request. Along with
6525 a set of delay_access directives to determine when it is used.
6526
6527 NOTE: If an IP address is a.b.c.d
6528 -> bits 25 through 32 are "d"
6529 -> bits 17 through 24 are "c"
6530 -> bits 17 through 32 are "c * 256 + d"
6531
6532 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
6533 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
6534
6535 This clause only supports fast acl types.
6536 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6537
6538 See also delay_parameters and delay_access.
6539DOC_END
6540
6541NAME: delay_access
6542TYPE: delay_pool_access
6543DEFAULT: none
6544DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
6545IFDEF: USE_DELAY_POOLS
6546LOC: Config.Delay
6547DOC_START
6548 This is used to determine which delay pool a request falls into.
6549
6550 delay_access is sorted per pool and the matching starts with pool 1,
6551 then pool 2, ..., and finally pool N. The first delay pool where the
6552 request is allowed is selected for the request. If it does not allow
6553 the request to any pool then the request is not delayed (default).
6554
6555 For example, if you want some_big_clients in delay
6556 pool 1 and lotsa_little_clients in delay pool 2:
6557
6558 delay_access 1 allow some_big_clients
6559 delay_access 1 deny all
6560 delay_access 2 allow lotsa_little_clients
6561 delay_access 2 deny all
6562 delay_access 3 allow authenticated_clients
6563
6564 See also delay_parameters and delay_class.
6565
6566DOC_END
6567
6568NAME: delay_parameters
6569TYPE: delay_pool_rates
6570DEFAULT: none
6571IFDEF: USE_DELAY_POOLS
6572LOC: Config.Delay
6573DOC_START
6574 This defines the parameters for a delay pool. Each delay pool has
6575 a number of "buckets" associated with it, as explained in the
6576 description of delay_class.
6577
6578 For a class 1 delay pool, the syntax is:
6579 delay_class pool 1
6580 delay_parameters pool aggregate
6581
6582 For a class 2 delay pool:
6583 delay_class pool 2
6584 delay_parameters pool aggregate individual
6585
6586 For a class 3 delay pool:
6587 delay_class pool 3
6588 delay_parameters pool aggregate network individual
6589
6590 For a class 4 delay pool:
6591 delay_class pool 4
6592 delay_parameters pool aggregate network individual user
6593
6594 For a class 5 delay pool:
6595 delay_class pool 5
6596 delay_parameters pool tagrate
6597
6598 The option variables are:
6599
6600 pool a pool number - ie, a number between 1 and the
6601 number specified in delay_pools as used in
6602 delay_class lines.
6603
6604 aggregate the speed limit parameters for the aggregate bucket
6605 (class 1, 2, 3).
6606
6607 individual the speed limit parameters for the individual
6608 buckets (class 2, 3).
6609
6610 network the speed limit parameters for the network buckets
6611 (class 3).
6612
6613 user the speed limit parameters for the user buckets
6614 (class 4).
6615
6616 tagrate the speed limit parameters for the tag buckets
6617 (class 5).
6618
6619 A pair of delay parameters is written restore/maximum, where restore is
6620 the number of bytes (not bits - modem and network speeds are usually
6621 quoted in bits) per second placed into the bucket, and maximum is the
6622 maximum number of bytes which can be in the bucket at any time.
6623
6624 There must be one delay_parameters line for each delay pool.
6625
6626
6627 For example, if delay pool number 1 is a class 2 delay pool as in the
6628 above example, and is being used to strictly limit each host to 64Kbit/sec
6629 (plus overheads), with no overall limit, the line is:
6630
6631 delay_parameters 1 none 8000/8000
6632
6633 Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
6634
6635 Note that the word 'none' is used to represent no limit.
6636
6637
6638 And, if delay pool number 2 is a class 3 delay pool as in the above
6639 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
6640 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
6641 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
6642 to permit a decent web page to be downloaded at a decent speed
6643 (if the network is not being limited due to overuse) but slow down
6644 large downloads more significantly:
6645
6646 delay_parameters 2 32000/32000 8000/8000 600/8000
6647
6648 Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
6649 8 x 8000 KByte/sec -> 64Kbit/sec.
6650 8 x 600 Byte/sec -> 4800bit/sec.
6651
6652
6653 Finally, for a class 4 delay pool as in the example - each user will
6654 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
6655
6656 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
6657
6658
6659 See also delay_class and delay_access.
6660
6661DOC_END
6662
6663NAME: delay_initial_bucket_level
6664COMMENT: (percent, 0-100)
6665TYPE: u_short
6666DEFAULT: 50
6667IFDEF: USE_DELAY_POOLS
6668LOC: Config.Delay.initial
6669DOC_START
6670 The initial bucket percentage is used to determine how much is put
6671 in each bucket when squid starts, is reconfigured, or first notices
6672 a host accessing it (in class 2 and class 3, individual hosts and
6673 networks only have buckets associated with them once they have been
6674 "seen" by squid).
6675DOC_END
6676
6677COMMENT_START
6678 CLIENT DELAY POOL PARAMETERS
6679 -----------------------------------------------------------------------------
6680COMMENT_END
6681
6682NAME: client_delay_pools
6683TYPE: client_delay_pool_count
6684DEFAULT: 0
6685IFDEF: USE_DELAY_POOLS
6686LOC: Config.ClientDelay
6687DOC_START
6688 This option specifies the number of client delay pools used. It must
6689 preceed other client_delay_* options.
6690
6691 Example:
6692 client_delay_pools 2
6693
6694 See also client_delay_parameters and client_delay_access.
6695DOC_END
6696
6697NAME: client_delay_initial_bucket_level
6698COMMENT: (percent, 0-no_limit)
6699TYPE: u_short
6700DEFAULT: 50
6701IFDEF: USE_DELAY_POOLS
6702LOC: Config.ClientDelay.initial
6703DOC_START
6704 This option determines the initial bucket size as a percentage of
6705 max_bucket_size from client_delay_parameters. Buckets are created
6706 at the time of the "first" connection from the matching IP. Idle
6707 buckets are periodically deleted up.
6708
6709 You can specify more than 100 percent but note that such "oversized"
6710 buckets are not refilled until their size goes down to max_bucket_size
6711 from client_delay_parameters.
6712
6713 Example:
6714 client_delay_initial_bucket_level 50
6715DOC_END
6716
6717NAME: client_delay_parameters
6718TYPE: client_delay_pool_rates
6719DEFAULT: none
6720IFDEF: USE_DELAY_POOLS
6721LOC: Config.ClientDelay
6722DOC_START
6723
6724 This option configures client-side bandwidth limits using the
6725 following format:
6726
6727 client_delay_parameters pool speed_limit max_bucket_size
6728
6729 pool is an integer ID used for client_delay_access matching.
6730
6731 speed_limit is bytes added to the bucket per second.
6732
6733 max_bucket_size is the maximum size of a bucket, enforced after any
6734 speed_limit additions.
6735
6736 Please see the delay_parameters option for more information and
6737 examples.
6738
6739 Example:
6740 client_delay_parameters 1 1024 2048
6741 client_delay_parameters 2 51200 16384
6742
6743 See also client_delay_access.
6744
6745DOC_END
6746
6747NAME: client_delay_access
6748TYPE: client_delay_pool_access
6749DEFAULT: none
6750DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
6751IFDEF: USE_DELAY_POOLS
6752LOC: Config.ClientDelay
6753DOC_START
6754 This option determines the client-side delay pool for the
6755 request:
6756
6757 client_delay_access pool_ID allow|deny acl_name
6758
6759 All client_delay_access options are checked in their pool ID
6760 order, starting with pool 1. The first checked pool with allowed
6761 request is selected for the request. If no ACL matches or there
6762 are no client_delay_access options, the request bandwidth is not
6763 limited.
6764
6765 The ACL-selected pool is then used to find the
6766 client_delay_parameters for the request. Client-side pools are
6767 not used to aggregate clients. Clients are always aggregated
6768 based on their source IP addresses (one bucket per source IP).
6769
6770 This clause only supports fast acl types.
6771 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6772 Additionally, only the client TCP connection details are available.
6773 ACLs testing HTTP properties will not work.
6774
6775 Please see delay_access for more examples.
6776
6777 Example:
6778 client_delay_access 1 allow low_rate_network
6779 client_delay_access 2 allow vips_network
6780
6781
6782 See also client_delay_parameters and client_delay_pools.
6783DOC_END
6784
6785COMMENT_START
6786 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
6787 -----------------------------------------------------------------------------
6788COMMENT_END
6789
6790NAME: wccp_router
6791TYPE: address
6792LOC: Config.Wccp.router
6793DEFAULT: any_addr
6794DEFAULT_DOC: WCCP disabled.
6795IFDEF: USE_WCCP
6796DOC_START
6797 Use this option to define your WCCP ``home'' router for
6798 Squid.
6799
6800 wccp_router supports a single WCCP(v1) router
6801
6802 wccp2_router supports multiple WCCPv2 routers
6803
6804 only one of the two may be used at the same time and defines
6805 which version of WCCP to use.
6806DOC_END
6807
6808NAME: wccp2_router
6809TYPE: IpAddress_list
6810LOC: Config.Wccp2.router
6811DEFAULT: none
6812DEFAULT_DOC: WCCPv2 disabled.
6813IFDEF: USE_WCCPv2
6814DOC_START
6815 Use this option to define your WCCP ``home'' router for
6816 Squid.
6817
6818 wccp_router supports a single WCCP(v1) router
6819
6820 wccp2_router supports multiple WCCPv2 routers
6821
6822 only one of the two may be used at the same time and defines
6823 which version of WCCP to use.
6824DOC_END
6825
6826NAME: wccp_version
6827TYPE: int
6828LOC: Config.Wccp.version
6829DEFAULT: 4
6830IFDEF: USE_WCCP
6831DOC_START
6832 This directive is only relevant if you need to set up WCCP(v1)
6833 to some very old and end-of-life Cisco routers. In all other
6834 setups it must be left unset or at the default setting.
6835 It defines an internal version in the WCCP(v1) protocol,
6836 with version 4 being the officially documented protocol.
6837
6838 According to some users, Cisco IOS 11.2 and earlier only
6839 support WCCP version 3. If you're using that or an earlier
6840 version of IOS, you may need to change this value to 3, otherwise
6841 do not specify this parameter.
6842DOC_END
6843
6844NAME: wccp2_rebuild_wait
6845TYPE: onoff
6846LOC: Config.Wccp2.rebuildwait
6847DEFAULT: on
6848IFDEF: USE_WCCPv2
6849DOC_START
6850 If this is enabled Squid will wait for the cache dir rebuild to finish
6851 before sending the first wccp2 HereIAm packet
6852DOC_END
6853
6854NAME: wccp2_forwarding_method
6855TYPE: wccp2_method
6856LOC: Config.Wccp2.forwarding_method
6857DEFAULT: gre
6858IFDEF: USE_WCCPv2
6859DOC_START
6860 WCCP2 allows the setting of forwarding methods between the
6861 router/switch and the cache. Valid values are as follows:
6862
6863 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6864 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6865
6866 Currently (as of IOS 12.4) cisco routers only support GRE.
6867 Cisco switches only support the L2 redirect assignment method.
6868DOC_END
6869
6870NAME: wccp2_return_method
6871TYPE: wccp2_method
6872LOC: Config.Wccp2.return_method
6873DEFAULT: gre
6874IFDEF: USE_WCCPv2
6875DOC_START
6876 WCCP2 allows the setting of return methods between the
6877 router/switch and the cache for packets that the cache
6878 decides not to handle. Valid values are as follows:
6879
6880 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6881 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6882
6883 Currently (as of IOS 12.4) cisco routers only support GRE.
6884 Cisco switches only support the L2 redirect assignment.
6885
6886 If the "ip wccp redirect exclude in" command has been
6887 enabled on the cache interface, then it is still safe for
6888 the proxy server to use a l2 redirect method even if this
6889 option is set to GRE.
6890DOC_END
6891
6892NAME: wccp2_assignment_method
6893TYPE: wccp2_amethod
6894LOC: Config.Wccp2.assignment_method
6895DEFAULT: hash
6896IFDEF: USE_WCCPv2
6897DOC_START
6898 WCCP2 allows the setting of methods to assign the WCCP hash
6899 Valid values are as follows:
6900
6901 hash - Hash assignment
6902 mask - Mask assignment
6903
6904 As a general rule, cisco routers support the hash assignment method
6905 and cisco switches support the mask assignment method.
6906DOC_END
6907
6908NAME: wccp2_service
6909TYPE: wccp2_service
6910LOC: Config.Wccp2.info
6911DEFAULT_IF_NONE: standard 0
6912DEFAULT_DOC: Use the 'web-cache' standard service.
6913IFDEF: USE_WCCPv2
6914DOC_START
6915 WCCP2 allows for multiple traffic services. There are two
6916 types: "standard" and "dynamic". The standard type defines
6917 one service id - http (id 0). The dynamic service ids can be from
6918 51 to 255 inclusive. In order to use a dynamic service id
6919 one must define the type of traffic to be redirected; this is done
6920 using the wccp2_service_info option.
6921
6922 The "standard" type does not require a wccp2_service_info option,
6923 just specifying the service id will suffice.
6924
6925 MD5 service authentication can be enabled by adding
6926 "password=<password>" to the end of this service declaration.
6927
6928 Examples:
6929
6930 wccp2_service standard 0 # for the 'web-cache' standard service
6931 wccp2_service dynamic 80 # a dynamic service type which will be
6932 # fleshed out with subsequent options.
6933 wccp2_service standard 0 password=foo
6934DOC_END
6935
6936NAME: wccp2_service_info
6937TYPE: wccp2_service_info
6938LOC: Config.Wccp2.info
6939DEFAULT: none
6940IFDEF: USE_WCCPv2
6941DOC_START
6942 Dynamic WCCPv2 services require further information to define the
6943 traffic you wish to have diverted.
6944
6945 The format is:
6946
6947 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6948 priority=<priority> ports=<port>,<port>..
6949
6950 The relevant WCCPv2 flags:
6951 + src_ip_hash, dst_ip_hash
6952 + source_port_hash, dst_port_hash
6953 + src_ip_alt_hash, dst_ip_alt_hash
6954 + src_port_alt_hash, dst_port_alt_hash
6955 + ports_source
6956
6957 The port list can be one to eight entries.
6958
6959 Example:
6960
6961 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6962 priority=240 ports=80
6963
6964 Note: the service id must have been defined by a previous
6965 'wccp2_service dynamic <id>' entry.
6966DOC_END
6967
6968NAME: wccp2_weight
6969TYPE: int
6970LOC: Config.Wccp2.weight
6971DEFAULT: 10000
6972IFDEF: USE_WCCPv2
6973DOC_START
6974 Each cache server gets assigned a set of the destination
6975 hash proportional to their weight.
6976DOC_END
6977
6978NAME: wccp_address
6979TYPE: address
6980LOC: Config.Wccp.address
6981DEFAULT: 0.0.0.0
6982DEFAULT_DOC: Address selected by the operating system.
6983IFDEF: USE_WCCP
6984DOC_START
6985 Use this option if you require WCCPv2 to use a specific
6986 interface address.
6987
6988 The default behavior is to not bind to any specific address.
6989DOC_END
6990
6991NAME: wccp2_address
6992TYPE: address
6993LOC: Config.Wccp2.address
6994DEFAULT: 0.0.0.0
6995DEFAULT_DOC: Address selected by the operating system.
6996IFDEF: USE_WCCPv2
6997DOC_START
6998 Use this option if you require WCCP to use a specific
6999 interface address.
7000
7001 The default behavior is to not bind to any specific address.
7002DOC_END
7003
7004COMMENT_START
7005 PERSISTENT CONNECTION HANDLING
7006 -----------------------------------------------------------------------------
7007
7008 Also see "pconn_timeout" in the TIMEOUTS section
7009COMMENT_END
7010
7011NAME: client_persistent_connections
7012TYPE: onoff
7013LOC: Config.onoff.client_pconns
7014DEFAULT: on
7015DOC_START
7016 Persistent connection support for clients.
7017 Squid uses persistent connections (when allowed). You can use
7018 this option to disable persistent connections with clients.
7019DOC_END
7020
7021NAME: server_persistent_connections
7022TYPE: onoff
7023LOC: Config.onoff.server_pconns
7024DEFAULT: on
7025DOC_START
7026 Persistent connection support for servers.
7027 Squid uses persistent connections (when allowed). You can use
7028 this option to disable persistent connections with servers.
7029DOC_END
7030
7031NAME: persistent_connection_after_error
7032TYPE: onoff
7033LOC: Config.onoff.error_pconns
7034DEFAULT: on
7035DOC_START
7036 With this directive the use of persistent connections after
7037 HTTP errors can be disabled. Useful if you have clients
7038 who fail to handle errors on persistent connections proper.
7039DOC_END
7040
7041NAME: detect_broken_pconn
7042TYPE: onoff
7043LOC: Config.onoff.detect_broken_server_pconns
7044DEFAULT: off
7045DOC_START
7046 Some servers have been found to incorrectly signal the use
7047 of HTTP/1.0 persistent connections even on replies not
7048 compatible, causing significant delays. This server problem
7049 has mostly been seen on redirects.
7050
7051 By enabling this directive Squid attempts to detect such
7052 broken replies and automatically assume the reply is finished
7053 after 10 seconds timeout.
7054DOC_END
7055
7056COMMENT_START
7057 CACHE DIGEST OPTIONS
7058 -----------------------------------------------------------------------------
7059COMMENT_END
7060
7061NAME: digest_generation
7062IFDEF: USE_CACHE_DIGESTS
7063TYPE: onoff
7064LOC: Config.onoff.digest_generation
7065DEFAULT: on
7066DOC_START
7067 This controls whether the server will generate a Cache Digest
7068 of its contents. By default, Cache Digest generation is
7069 enabled if Squid is compiled with --enable-cache-digests defined.
7070DOC_END
7071
7072NAME: digest_bits_per_entry
7073IFDEF: USE_CACHE_DIGESTS
7074TYPE: int
7075LOC: Config.digest.bits_per_entry
7076DEFAULT: 5
7077DOC_START
7078 This is the number of bits of the server's Cache Digest which
7079 will be associated with the Digest entry for a given HTTP
7080 Method and URL (public key) combination. The default is 5.
7081DOC_END
7082
7083NAME: digest_rebuild_period
7084IFDEF: USE_CACHE_DIGESTS
7085COMMENT: (seconds)
7086TYPE: time_t
7087LOC: Config.digest.rebuild_period
7088DEFAULT: 1 hour
7089DOC_START
7090 This is the wait time between Cache Digest rebuilds.
7091DOC_END
7092
7093NAME: digest_rewrite_period
7094COMMENT: (seconds)
7095IFDEF: USE_CACHE_DIGESTS
7096TYPE: time_t
7097LOC: Config.digest.rewrite_period
7098DEFAULT: 1 hour
7099DOC_START
7100 This is the wait time between Cache Digest writes to
7101 disk.
7102DOC_END
7103
7104NAME: digest_swapout_chunk_size
7105COMMENT: (bytes)
7106TYPE: b_size_t
7107IFDEF: USE_CACHE_DIGESTS
7108LOC: Config.digest.swapout_chunk_size
7109DEFAULT: 4096 bytes
7110DOC_START
7111 This is the number of bytes of the Cache Digest to write to
7112 disk at a time. It defaults to 4096 bytes (4KB), the Squid
7113 default swap page.
7114DOC_END
7115
7116NAME: digest_rebuild_chunk_percentage
7117COMMENT: (percent, 0-100)
7118IFDEF: USE_CACHE_DIGESTS
7119TYPE: int
7120LOC: Config.digest.rebuild_chunk_percentage
7121DEFAULT: 10
7122DOC_START
7123 This is the percentage of the Cache Digest to be scanned at a
7124 time. By default it is set to 10% of the Cache Digest.
7125DOC_END
7126
7127COMMENT_START
7128 SNMP OPTIONS
7129 -----------------------------------------------------------------------------
7130COMMENT_END
7131
7132NAME: snmp_port
7133TYPE: u_short
7134LOC: Config.Port.snmp
7135DEFAULT: 0
7136DEFAULT_DOC: SNMP disabled.
7137IFDEF: SQUID_SNMP
7138DOC_START
7139 The port number where Squid listens for SNMP requests. To enable
7140 SNMP support set this to a suitable port number. Port number
7141 3401 is often used for the Squid SNMP agent. By default it's
7142 set to "0" (disabled)
7143
7144 Example:
7145 snmp_port 3401
7146DOC_END
7147
7148NAME: snmp_access
7149TYPE: acl_access
7150LOC: Config.accessList.snmp
7151DEFAULT: none
7152DEFAULT_DOC: Deny, unless rules exist in squid.conf.
7153IFDEF: SQUID_SNMP
7154DOC_START
7155 Allowing or denying access to the SNMP port.
7156
7157 All access to the agent is denied by default.
7158 usage:
7159
7160 snmp_access allow|deny [!]aclname ...
7161
7162 This clause only supports fast acl types.
7163 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7164
7165Example:
7166 snmp_access allow snmppublic localhost
7167 snmp_access deny all
7168DOC_END
7169
7170NAME: snmp_incoming_address
7171TYPE: address
7172LOC: Config.Addrs.snmp_incoming
7173DEFAULT: any_addr
7174DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
7175IFDEF: SQUID_SNMP
7176DOC_START
7177 Just like 'udp_incoming_address', but for the SNMP port.
7178
7179 snmp_incoming_address is used for the SNMP socket receiving
7180 messages from SNMP agents.
7181
7182 The default snmp_incoming_address is to listen on all
7183 available network interfaces.
7184DOC_END
7185
7186NAME: snmp_outgoing_address
7187TYPE: address
7188LOC: Config.Addrs.snmp_outgoing
7189DEFAULT: no_addr
7190DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
7191IFDEF: SQUID_SNMP
7192DOC_START
7193 Just like 'udp_outgoing_address', but for the SNMP port.
7194
7195 snmp_outgoing_address is used for SNMP packets returned to SNMP
7196 agents.
7197
7198 If snmp_outgoing_address is not set it will use the same socket
7199 as snmp_incoming_address. Only change this if you want to have
7200 SNMP replies sent using another address than where this Squid
7201 listens for SNMP queries.
7202
7203 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
7204 the same value since they both use the same port.
7205DOC_END
7206
7207COMMENT_START
7208 ICP OPTIONS
7209 -----------------------------------------------------------------------------
7210COMMENT_END
7211
7212NAME: icp_port udp_port
7213TYPE: u_short
7214DEFAULT: 0
7215DEFAULT_DOC: ICP disabled.
7216LOC: Config.Port.icp
7217DOC_START
7218 The port number where Squid sends and receives ICP queries to
7219 and from neighbor caches. The standard UDP port for ICP is 3130.
7220
7221 Example:
7222 icp_port @DEFAULT_ICP_PORT@
7223DOC_END
7224
7225NAME: htcp_port
7226IFDEF: USE_HTCP
7227TYPE: u_short
7228DEFAULT: 0
7229DEFAULT_DOC: HTCP disabled.
7230LOC: Config.Port.htcp
7231DOC_START
7232 The port number where Squid sends and receives HTCP queries to
7233 and from neighbor caches. To turn it on you want to set it to
7234 4827.
7235
7236 Example:
7237 htcp_port 4827
7238DOC_END
7239
7240NAME: log_icp_queries
7241COMMENT: on|off
7242TYPE: onoff
7243DEFAULT: on
7244LOC: Config.onoff.log_udp
7245DOC_START
7246 If set, ICP queries are logged to access.log. You may wish
7247 do disable this if your ICP load is VERY high to speed things
7248 up or to simplify log analysis.
7249DOC_END
7250
7251NAME: udp_incoming_address
7252TYPE: address
7253LOC:Config.Addrs.udp_incoming
7254DEFAULT: any_addr
7255DEFAULT_DOC: Accept packets from all machine interfaces.
7256DOC_START
7257 udp_incoming_address is used for UDP packets received from other
7258 caches.
7259
7260 The default behavior is to not bind to any specific address.
7261
7262 Only change this if you want to have all UDP queries received on
7263 a specific interface/address.
7264
7265 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
7266 modules. Altering it will affect all of them in the same manner.
7267
7268 see also; udp_outgoing_address
7269
7270 NOTE, udp_incoming_address and udp_outgoing_address can not
7271 have the same value since they both use the same port.
7272DOC_END
7273
7274NAME: udp_outgoing_address
7275TYPE: address
7276LOC: Config.Addrs.udp_outgoing
7277DEFAULT: no_addr
7278DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
7279DOC_START
7280 udp_outgoing_address is used for UDP packets sent out to other
7281 caches.
7282
7283 The default behavior is to not bind to any specific address.
7284
7285 Instead it will use the same socket as udp_incoming_address.
7286 Only change this if you want to have UDP queries sent using another
7287 address than where this Squid listens for UDP queries from other
7288 caches.
7289
7290 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
7291 modules. Altering it will affect all of them in the same manner.
7292
7293 see also; udp_incoming_address
7294
7295 NOTE, udp_incoming_address and udp_outgoing_address can not
7296 have the same value since they both use the same port.
7297DOC_END
7298
7299NAME: icp_hit_stale
7300COMMENT: on|off
7301TYPE: onoff
7302DEFAULT: off
7303LOC: Config.onoff.icp_hit_stale
7304DOC_START
7305 If you want to return ICP_HIT for stale cache objects, set this
7306 option to 'on'. If you have sibling relationships with caches
7307 in other administrative domains, this should be 'off'. If you only
7308 have sibling relationships with caches under your control,
7309 it is probably okay to set this to 'on'.
7310 If set to 'on', your siblings should use the option "allow-miss"
7311 on their cache_peer lines for connecting to you.
7312DOC_END
7313
7314NAME: minimum_direct_hops
7315TYPE: int
7316DEFAULT: 4
7317LOC: Config.minDirectHops
7318DOC_START
7319 If using the ICMP pinging stuff, do direct fetches for sites
7320 which are no more than this many hops away.
7321DOC_END
7322
7323NAME: minimum_direct_rtt
7324COMMENT: (msec)
7325TYPE: int
7326DEFAULT: 400
7327LOC: Config.minDirectRtt
7328DOC_START
7329 If using the ICMP pinging stuff, do direct fetches for sites
7330 which are no more than this many rtt milliseconds away.
7331DOC_END
7332
7333NAME: netdb_low
7334TYPE: int
7335DEFAULT: 900
7336LOC: Config.Netdb.low
7337DOC_START
7338 The low water mark for the ICMP measurement database.
7339
7340 Note: high watermark controlled by netdb_high directive.
7341
7342 These watermarks are counts, not percents. The defaults are
7343 (low) 900 and (high) 1000. When the high water mark is
7344 reached, database entries will be deleted until the low
7345 mark is reached.
7346DOC_END
7347
7348NAME: netdb_high
7349TYPE: int
7350DEFAULT: 1000
7351LOC: Config.Netdb.high
7352DOC_START
7353 The high water mark for the ICMP measurement database.
7354
7355 Note: low watermark controlled by netdb_low directive.
7356
7357 These watermarks are counts, not percents. The defaults are
7358 (low) 900 and (high) 1000. When the high water mark is
7359 reached, database entries will be deleted until the low
7360 mark is reached.
7361DOC_END
7362
7363NAME: netdb_ping_period
7364TYPE: time_t
7365LOC: Config.Netdb.period
7366DEFAULT: 5 minutes
7367DOC_START
7368 The minimum period for measuring a site. There will be at
7369 least this much delay between successive pings to the same
7370 network. The default is five minutes.
7371DOC_END
7372
7373NAME: query_icmp
7374COMMENT: on|off
7375TYPE: onoff
7376DEFAULT: off
7377LOC: Config.onoff.query_icmp
7378DOC_START
7379 If you want to ask your peers to include ICMP data in their ICP
7380 replies, enable this option.
7381
7382 If your peer has configured Squid (during compilation) with
7383 '--enable-icmp' that peer will send ICMP pings to origin server
7384 sites of the URLs it receives. If you enable this option the
7385 ICP replies from that peer will include the ICMP data (if available).
7386 Then, when choosing a parent cache, Squid will choose the parent with
7387 the minimal RTT to the origin server. When this happens, the
7388 hierarchy field of the access.log will be
7389 "CLOSEST_PARENT_MISS". This option is off by default.
7390DOC_END
7391
7392NAME: test_reachability
7393COMMENT: on|off
7394TYPE: onoff
7395DEFAULT: off
7396LOC: Config.onoff.test_reachability
7397DOC_START
7398 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
7399 instead of ICP_MISS if the target host is NOT in the ICMP
7400 database, or has a zero RTT.
7401DOC_END
7402
7403NAME: icp_query_timeout
7404COMMENT: (msec)
7405DEFAULT: 0
7406DEFAULT_DOC: Dynamic detection.
7407TYPE: int
7408LOC: Config.Timeout.icp_query
7409DOC_START
7410 Normally Squid will automatically determine an optimal ICP
7411 query timeout value based on the round-trip-time of recent ICP
7412 queries. If you want to override the value determined by
7413 Squid, set this 'icp_query_timeout' to a non-zero value. This
7414 value is specified in MILLISECONDS, so, to use a 2-second
7415 timeout (the old default), you would write:
7416
7417 icp_query_timeout 2000
7418DOC_END
7419
7420NAME: maximum_icp_query_timeout
7421COMMENT: (msec)
7422DEFAULT: 2000
7423TYPE: int
7424LOC: Config.Timeout.icp_query_max
7425DOC_START
7426 Normally the ICP query timeout is determined dynamically. But
7427 sometimes it can lead to very large values (say 5 seconds).
7428 Use this option to put an upper limit on the dynamic timeout
7429 value. Do NOT use this option to always use a fixed (instead
7430 of a dynamic) timeout value. To set a fixed timeout see the
7431 'icp_query_timeout' directive.
7432DOC_END
7433
7434NAME: minimum_icp_query_timeout
7435COMMENT: (msec)
7436DEFAULT: 5
7437TYPE: int
7438LOC: Config.Timeout.icp_query_min
7439DOC_START
7440 Normally the ICP query timeout is determined dynamically. But
7441 sometimes it can lead to very small timeouts, even lower than
7442 the normal latency variance on your link due to traffic.
7443 Use this option to put an lower limit on the dynamic timeout
7444 value. Do NOT use this option to always use a fixed (instead
7445 of a dynamic) timeout value. To set a fixed timeout see the
7446 'icp_query_timeout' directive.
7447DOC_END
7448
7449NAME: background_ping_rate
7450COMMENT: time-units
7451TYPE: time_t
7452DEFAULT: 10 seconds
7453LOC: Config.backgroundPingRate
7454DOC_START
7455 Controls how often the ICP pings are sent to siblings that
7456 have background-ping set.
7457DOC_END
7458
7459COMMENT_START
7460 MULTICAST ICP OPTIONS
7461 -----------------------------------------------------------------------------
7462COMMENT_END
7463
7464NAME: mcast_groups
7465TYPE: wordlist
7466LOC: Config.mcast_group_list
7467DEFAULT: none
7468DOC_START
7469 This tag specifies a list of multicast groups which your server
7470 should join to receive multicasted ICP queries.
7471
7472 NOTE! Be very careful what you put here! Be sure you
7473 understand the difference between an ICP _query_ and an ICP
7474 _reply_. This option is to be set only if you want to RECEIVE
7475 multicast queries. Do NOT set this option to SEND multicast
7476 ICP (use cache_peer for that). ICP replies are always sent via
7477 unicast, so this option does not affect whether or not you will
7478 receive replies from multicast group members.
7479
7480 You must be very careful to NOT use a multicast address which
7481 is already in use by another group of caches.
7482
7483 If you are unsure about multicast, please read the Multicast
7484 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
7485
7486 Usage: mcast_groups 239.128.16.128 224.0.1.20
7487
7488 By default, Squid doesn't listen on any multicast groups.
7489DOC_END
7490
7491NAME: mcast_miss_addr
7492IFDEF: MULTICAST_MISS_STREAM
7493TYPE: address
7494LOC: Config.mcast_miss.addr
7495DEFAULT: no_addr
7496DEFAULT_DOC: disabled.
7497DOC_START
7498 If you enable this option, every "cache miss" URL will
7499 be sent out on the specified multicast address.
7500
7501 Do not enable this option unless you are are absolutely
7502 certain you understand what you are doing.
7503DOC_END
7504
7505NAME: mcast_miss_ttl
7506IFDEF: MULTICAST_MISS_STREAM
7507TYPE: u_short
7508LOC: Config.mcast_miss.ttl
7509DEFAULT: 16
7510DOC_START
7511 This is the time-to-live value for packets multicasted
7512 when multicasting off cache miss URLs is enabled. By
7513 default this is set to 'site scope', i.e. 16.
7514DOC_END
7515
7516NAME: mcast_miss_port
7517IFDEF: MULTICAST_MISS_STREAM
7518TYPE: u_short
7519LOC: Config.mcast_miss.port
7520DEFAULT: 3135
7521DOC_START
7522 This is the port number to be used in conjunction with
7523 'mcast_miss_addr'.
7524DOC_END
7525
7526NAME: mcast_miss_encode_key
7527IFDEF: MULTICAST_MISS_STREAM
7528TYPE: string
7529LOC: Config.mcast_miss.encode_key
7530DEFAULT: XXXXXXXXXXXXXXXX
7531DOC_START
7532 The URLs that are sent in the multicast miss stream are
7533 encrypted. This is the encryption key.
7534DOC_END
7535
7536NAME: mcast_icp_query_timeout
7537COMMENT: (msec)
7538DEFAULT: 2000
7539TYPE: int
7540LOC: Config.Timeout.mcast_icp_query
7541DOC_START
7542 For multicast peers, Squid regularly sends out ICP "probes" to
7543 count how many other peers are listening on the given multicast
7544 address. This value specifies how long Squid should wait to
7545 count all the replies. The default is 2000 msec, or 2
7546 seconds.
7547DOC_END
7548
7549COMMENT_START
7550 INTERNAL ICON OPTIONS
7551 -----------------------------------------------------------------------------
7552COMMENT_END
7553
7554NAME: icon_directory
7555TYPE: string
7556LOC: Config.icons.directory
7557DEFAULT: @DEFAULT_ICON_DIR@
7558DOC_START
7559 Where the icons are stored. These are normally kept in
7560 @DEFAULT_ICON_DIR@
7561DOC_END
7562
7563NAME: global_internal_static
7564TYPE: onoff
7565LOC: Config.onoff.global_internal_static
7566DEFAULT: on
7567DOC_START
7568 This directive controls is Squid should intercept all requests for
7569 /squid-internal-static/ no matter which host the URL is requesting
7570 (default on setting), or if nothing special should be done for
7571 such URLs (off setting). The purpose of this directive is to make
7572 icons etc work better in complex cache hierarchies where it may
7573 not always be possible for all corners in the cache mesh to reach
7574 the server generating a directory listing.
7575DOC_END
7576
7577NAME: short_icon_urls
7578TYPE: onoff
7579LOC: Config.icons.use_short_names
7580DEFAULT: on
7581DOC_START
7582 If this is enabled Squid will use short URLs for icons.
7583 If disabled it will revert to the old behavior of including
7584 it's own name and port in the URL.
7585
7586 If you run a complex cache hierarchy with a mix of Squid and
7587 other proxies you may need to disable this directive.
7588DOC_END
7589
7590COMMENT_START
7591 ERROR PAGE OPTIONS
7592 -----------------------------------------------------------------------------
7593COMMENT_END
7594
7595NAME: error_directory
7596TYPE: string
7597LOC: Config.errorDirectory
7598DEFAULT: none
7599DEFAULT_DOC: Send error pages in the clients preferred language
7600DOC_START
7601 If you wish to create your own versions of the default
7602 error files to customize them to suit your company copy
7603 the error/template files to another directory and point
7604 this tag at them.
7605
7606 WARNING: This option will disable multi-language support
7607 on error pages if used.
7608
7609 The squid developers are interested in making squid available in
7610 a wide variety of languages. If you are making translations for a
7611 language that Squid does not currently provide please consider
7612 contributing your translation back to the project.
7613 http://wiki.squid-cache.org/Translations
7614
7615 The squid developers working on translations are happy to supply drop-in
7616 translated error files in exchange for any new language contributions.
7617DOC_END
7618
7619NAME: error_default_language
7620IFDEF: USE_ERR_LOCALES
7621TYPE: string
7622LOC: Config.errorDefaultLanguage
7623DEFAULT: none
7624DEFAULT_DOC: Generate English language pages.
7625DOC_START
7626 Set the default language which squid will send error pages in
7627 if no existing translation matches the clients language
7628 preferences.
7629
7630 If unset (default) generic English will be used.
7631
7632 The squid developers are interested in making squid available in
7633 a wide variety of languages. If you are interested in making
7634 translations for any language see the squid wiki for details.
7635 http://wiki.squid-cache.org/Translations
7636DOC_END
7637
7638NAME: error_log_languages
7639IFDEF: USE_ERR_LOCALES
7640TYPE: onoff
7641LOC: Config.errorLogMissingLanguages
7642DEFAULT: on
7643DOC_START
7644 Log to cache.log what languages users are attempting to
7645 auto-negotiate for translations.
7646
7647 Successful negotiations are not logged. Only failures
7648 have meaning to indicate that Squid may need an upgrade
7649 of its error page translations.
7650DOC_END
7651
7652NAME: err_page_stylesheet
7653TYPE: string
7654LOC: Config.errorStylesheet
7655DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
7656DOC_START
7657 CSS Stylesheet to pattern the display of Squid default error pages.
7658
7659 For information on CSS see http://www.w3.org/Style/CSS/
7660DOC_END
7661
7662NAME: err_html_text
7663TYPE: eol
7664LOC: Config.errHtmlText
7665DEFAULT: none
7666DOC_START
7667 HTML text to include in error messages. Make this a "mailto"
7668 URL to your admin address, or maybe just a link to your
7669 organizations Web page.
7670
7671 To include this in your error messages, you must rewrite
7672 the error template files (found in the "errors" directory).
7673 Wherever you want the 'err_html_text' line to appear,
7674 insert a %L tag in the error template file.
7675DOC_END
7676
7677NAME: email_err_data
7678COMMENT: on|off
7679TYPE: onoff
7680LOC: Config.onoff.emailErrData
7681DEFAULT: on
7682DOC_START
7683 If enabled, information about the occurred error will be
7684 included in the mailto links of the ERR pages (if %W is set)
7685 so that the email body contains the data.
7686 Syntax is <A HREF="mailto:%w%W">%w</A>
7687DOC_END
7688
7689NAME: deny_info
7690TYPE: denyinfo
7691LOC: Config.denyInfoList
7692DEFAULT: none
7693DOC_START
7694 Usage: deny_info err_page_name acl
7695 or deny_info http://... acl
7696 or deny_info TCP_RESET acl
7697
7698 This can be used to return a ERR_ page for requests which
7699 do not pass the 'http_access' rules. Squid remembers the last
7700 acl it evaluated in http_access, and if a 'deny_info' line exists
7701 for that ACL Squid returns a corresponding error page.
7702
7703 The acl is typically the last acl on the http_access deny line which
7704 denied access. The exceptions to this rule are:
7705 - When Squid needs to request authentication credentials. It's then
7706 the first authentication related acl encountered
7707 - When none of the http_access lines matches. It's then the last
7708 acl processed on the last http_access line.
7709 - When the decision to deny access was made by an adaptation service,
7710 the acl name is the corresponding eCAP or ICAP service_name.
7711
7712 NP: If providing your own custom error pages with error_directory
7713 you may also specify them by your custom file name:
7714 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
7715
7716 By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
7717 may be specified by prefixing the file name with the code and a colon.
7718 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
7719
7720 Alternatively you can tell Squid to reset the TCP connection
7721 by specifying TCP_RESET.
7722
7723 Or you can specify an error URL or URL pattern. The browsers will
7724 get redirected to the specified URL after formatting tags have
7725 been replaced. Redirect will be done with 302 or 307 according to
7726 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
7727 the URL. e.g. 303:http://example.com/
7728
7729 URL FORMAT TAGS:
7730 %a - username (if available. Password NOT included)
7731 %B - FTP path URL
7732 %e - Error number
7733 %E - Error description
7734 %h - Squid hostname
7735 %H - Request domain name
7736 %i - Client IP Address
7737 %M - Request Method
7738 %o - Message result from external ACL helper
7739 %p - Request Port number
7740 %P - Request Protocol name
7741 %R - Request URL path
7742 %T - Timestamp in RFC 1123 format
7743 %U - Full canonical URL from client
7744 (HTTPS URLs terminate with *)
7745 %u - Full canonical URL from client
7746 %w - Admin email from squid.conf
7747 %x - Error name
7748 %% - Literal percent (%) code
7749
7750DOC_END
7751
7752COMMENT_START
7753 OPTIONS INFLUENCING REQUEST FORWARDING
7754 -----------------------------------------------------------------------------
7755COMMENT_END
7756
7757NAME: nonhierarchical_direct
7758TYPE: onoff
7759LOC: Config.onoff.nonhierarchical_direct
7760DEFAULT: on
7761DOC_START
7762 By default, Squid will send any non-hierarchical requests
7763 (not cacheable request type) direct to origin servers.
7764
7765 When this is set to "off", Squid will prefer to send these
7766 requests to parents.
7767
7768 Note that in most configurations, by turning this off you will only
7769 add latency to these request without any improvement in global hit
7770 ratio.
7771
7772 This option only sets a preference. If the parent is unavailable a
7773 direct connection to the origin server may still be attempted. To
7774 completely prevent direct connections use never_direct.
7775DOC_END
7776
7777NAME: prefer_direct
7778TYPE: onoff
7779LOC: Config.onoff.prefer_direct
7780DEFAULT: off
7781DOC_START
7782 Normally Squid tries to use parents for most requests. If you for some
7783 reason like it to first try going direct and only use a parent if
7784 going direct fails set this to on.
7785
7786 By combining nonhierarchical_direct off and prefer_direct on you
7787 can set up Squid to use a parent as a backup path if going direct
7788 fails.
7789
7790 Note: If you want Squid to use parents for all requests see
7791 the never_direct directive. prefer_direct only modifies how Squid
7792 acts on cacheable requests.
7793DOC_END
7794
7795NAME: cache_miss_revalidate
7796COMMENT: on|off
7797TYPE: onoff
7798DEFAULT: on
7799LOC: Config.onoff.cache_miss_revalidate
7800DOC_START
7801 RFC 7232 defines a conditional request mechanism to prevent
7802 response objects being unnecessarily transferred over the network.
7803 If that mechanism is used by the client and a cache MISS occurs
7804 it can prevent new cache entries being created.
7805
7806 This option determines whether Squid on cache MISS will pass the
7807 client revalidation request to the server or tries to fetch new
7808 content for caching. It can be useful while the cache is mostly
7809 empty to more quickly have the cache populated by generating
7810 non-conditional GETs.
7811
7812 When set to 'on' (default), Squid will pass all client If-* headers
7813 to the server. This permits server responses without a cacheable
7814 payload to be delivered and on MISS no new cache entry is created.
7815
7816 When set to 'off' and if the request is cacheable, Squid will
7817 remove the clients If-Modified-Since and If-None-Match headers from
7818 the request sent to the server. This requests a 200 status response
7819 from the server to create a new cache entry with.
7820DOC_END
7821
7822NAME: always_direct
7823TYPE: acl_access
7824LOC: Config.accessList.AlwaysDirect
7825DEFAULT: none
7826DEFAULT_DOC: Prevent any cache_peer being used for this request.
7827DOC_START
7828 Usage: always_direct allow|deny [!]aclname ...
7829
7830 Here you can use ACL elements to specify requests which should
7831 ALWAYS be forwarded by Squid to the origin servers without using
7832 any peers. For example, to always directly forward requests for
7833 local servers ignoring any parents or siblings you may have use
7834 something like:
7835
7836 acl local-servers dstdomain my.domain.net
7837 always_direct allow local-servers
7838
7839 To always forward FTP requests directly, use
7840
7841 acl FTP proto FTP
7842 always_direct allow FTP
7843
7844 NOTE: There is a similar, but opposite option named
7845 'never_direct'. You need to be aware that "always_direct deny
7846 foo" is NOT the same thing as "never_direct allow foo". You
7847 may need to use a deny rule to exclude a more-specific case of
7848 some other rule. Example:
7849
7850 acl local-external dstdomain external.foo.net
7851 acl local-servers dstdomain .foo.net
7852 always_direct deny local-external
7853 always_direct allow local-servers
7854
7855 NOTE: If your goal is to make the client forward the request
7856 directly to the origin server bypassing Squid then this needs
7857 to be done in the client configuration. Squid configuration
7858 can only tell Squid how Squid should fetch the object.
7859
7860 NOTE: This directive is not related to caching. The replies
7861 is cached as usual even if you use always_direct. To not cache
7862 the replies see the 'cache' directive.
7863
7864 This clause supports both fast and slow acl types.
7865 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7866DOC_END
7867
7868NAME: never_direct
7869TYPE: acl_access
7870LOC: Config.accessList.NeverDirect
7871DEFAULT: none
7872DEFAULT_DOC: Allow DNS results to be used for this request.
7873DOC_START
7874 Usage: never_direct allow|deny [!]aclname ...
7875
7876 never_direct is the opposite of always_direct. Please read
7877 the description for always_direct if you have not already.
7878
7879 With 'never_direct' you can use ACL elements to specify
7880 requests which should NEVER be forwarded directly to origin
7881 servers. For example, to force the use of a proxy for all
7882 requests, except those in your local domain use something like:
7883
7884 acl local-servers dstdomain .foo.net
7885 never_direct deny local-servers
7886 never_direct allow all
7887
7888 or if Squid is inside a firewall and there are local intranet
7889 servers inside the firewall use something like:
7890
7891 acl local-intranet dstdomain .foo.net
7892 acl local-external dstdomain external.foo.net
7893 always_direct deny local-external
7894 always_direct allow local-intranet
7895 never_direct allow all
7896
7897 This clause supports both fast and slow acl types.
7898 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7899DOC_END
7900
7901COMMENT_START
7902 ADVANCED NETWORKING OPTIONS
7903 -----------------------------------------------------------------------------
7904COMMENT_END
7905
7906NAME: incoming_udp_average incoming_icp_average
7907TYPE: int
7908DEFAULT: 6
7909LOC: Config.comm_incoming.udp.average
7910DOC_START
7911 Heavy voodoo here. I can't even believe you are reading this.
7912 Are you crazy? Don't even think about adjusting these unless
7913 you understand the algorithms in comm_select.c first!
7914DOC_END
7915
7916NAME: incoming_tcp_average incoming_http_average
7917TYPE: int
7918DEFAULT: 4
7919LOC: Config.comm_incoming.tcp.average
7920DOC_START
7921 Heavy voodoo here. I can't even believe you are reading this.
7922 Are you crazy? Don't even think about adjusting these unless
7923 you understand the algorithms in comm_select.c first!
7924DOC_END
7925
7926NAME: incoming_dns_average
7927TYPE: int
7928DEFAULT: 4
7929LOC: Config.comm_incoming.dns.average
7930DOC_START
7931 Heavy voodoo here. I can't even believe you are reading this.
7932 Are you crazy? Don't even think about adjusting these unless
7933 you understand the algorithms in comm_select.c first!
7934DOC_END
7935
7936NAME: min_udp_poll_cnt min_icp_poll_cnt
7937TYPE: int
7938DEFAULT: 8
7939LOC: Config.comm_incoming.udp.min_poll
7940DOC_START
7941 Heavy voodoo here. I can't even believe you are reading this.
7942 Are you crazy? Don't even think about adjusting these unless
7943 you understand the algorithms in comm_select.c first!
7944DOC_END
7945
7946NAME: min_dns_poll_cnt
7947TYPE: int
7948DEFAULT: 8
7949LOC: Config.comm_incoming.dns.min_poll
7950DOC_START
7951 Heavy voodoo here. I can't even believe you are reading this.
7952 Are you crazy? Don't even think about adjusting these unless
7953 you understand the algorithms in comm_select.c first!
7954DOC_END
7955
7956NAME: min_tcp_poll_cnt min_http_poll_cnt
7957TYPE: int
7958DEFAULT: 8
7959LOC: Config.comm_incoming.tcp.min_poll
7960DOC_START
7961 Heavy voodoo here. I can't even believe you are reading this.
7962 Are you crazy? Don't even think about adjusting these unless
7963 you understand the algorithms in comm_select.c first!
7964DOC_END
7965
7966NAME: accept_filter
7967TYPE: string
7968DEFAULT: none
7969LOC: Config.accept_filter
7970DOC_START
7971 FreeBSD:
7972
7973 The name of an accept(2) filter to install on Squid's
7974 listen socket(s). This feature is perhaps specific to
7975 FreeBSD and requires support in the kernel.
7976
7977 The 'httpready' filter delays delivering new connections
7978 to Squid until a full HTTP request has been received.
7979 See the accf_http(9) man page for details.
7980
7981 The 'dataready' filter delays delivering new connections
7982 to Squid until there is some data to process.
7983 See the accf_dataready(9) man page for details.
7984
7985 Linux:
7986
7987 The 'data' filter delays delivering of new connections
7988 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
7989 You may optionally specify a number of seconds to wait by
7990 'data=N' where N is the number of seconds. Defaults to 30
7991 if not specified. See the tcp(7) man page for details.
7992EXAMPLE:
7993# FreeBSD
7994accept_filter httpready
7995# Linux
7996accept_filter data
7997DOC_END
7998
7999NAME: client_ip_max_connections
8000TYPE: int
8001LOC: Config.client_ip_max_connections
8002DEFAULT: -1
8003DEFAULT_DOC: No limit.
8004DOC_START
8005 Set an absolute limit on the number of connections a single
8006 client IP can use. Any more than this and Squid will begin to drop
8007 new connections from the client until it closes some links.
8008
8009 Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
8010 connections from the client. For finer control use the ACL access controls.
8011
8012 Requires client_db to be enabled (the default).
8013
8014 WARNING: This may noticably slow down traffic received via external proxies
8015 or NAT devices and cause them to rebound error messages back to their clients.
8016DOC_END
8017
8018NAME: tcp_recv_bufsize
8019COMMENT: (bytes)
8020TYPE: b_size_t
8021DEFAULT: 0 bytes
8022DEFAULT_DOC: Use operating system TCP defaults.
8023LOC: Config.tcpRcvBufsz
8024DOC_START
8025 Size of receive buffer to set for TCP sockets. Probably just
8026 as easy to change your kernel's default.
8027 Omit from squid.conf to use the default buffer size.
8028DOC_END
8029
8030COMMENT_START
8031 ICAP OPTIONS
8032 -----------------------------------------------------------------------------
8033COMMENT_END
8034
8035NAME: icap_enable
8036TYPE: onoff
8037IFDEF: ICAP_CLIENT
8038COMMENT: on|off
8039LOC: Adaptation::Icap::TheConfig.onoff
8040DEFAULT: off
8041DOC_START
8042 If you want to enable the ICAP module support, set this to on.
8043DOC_END
8044
8045NAME: icap_connect_timeout
8046TYPE: time_t
8047DEFAULT: none
8048LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
8049IFDEF: ICAP_CLIENT
8050DOC_START
8051 This parameter specifies how long to wait for the TCP connect to
8052 the requested ICAP server to complete before giving up and either
8053 terminating the HTTP transaction or bypassing the failure.
8054
8055 The default for optional services is peer_connect_timeout.
8056 The default for essential services is connect_timeout.
8057 If this option is explicitly set, its value applies to all services.
8058DOC_END
8059
8060NAME: icap_io_timeout
8061COMMENT: time-units
8062TYPE: time_t
8063DEFAULT: none
8064DEFAULT_DOC: Use read_timeout.
8065LOC: Adaptation::Icap::TheConfig.io_timeout_raw
8066IFDEF: ICAP_CLIENT
8067DOC_START
8068 This parameter specifies how long to wait for an I/O activity on
8069 an established, active ICAP connection before giving up and
8070 either terminating the HTTP transaction or bypassing the
8071 failure.
8072DOC_END
8073
8074NAME: icap_service_failure_limit
8075COMMENT: limit [in memory-depth time-units]
8076TYPE: icap_service_failure_limit
8077IFDEF: ICAP_CLIENT
8078LOC: Adaptation::Icap::TheConfig
8079DEFAULT: 10
8080DOC_START
8081 The limit specifies the number of failures that Squid tolerates
8082 when establishing a new TCP connection with an ICAP service. If
8083 the number of failures exceeds the limit, the ICAP service is
8084 not used for new ICAP requests until it is time to refresh its
8085 OPTIONS.
8086
8087 A negative value disables the limit. Without the limit, an ICAP
8088 service will not be considered down due to connectivity failures
8089 between ICAP OPTIONS requests.
8090
8091 Squid forgets ICAP service failures older than the specified
8092 value of memory-depth. The memory fading algorithm
8093 is approximate because Squid does not remember individual
8094 errors but groups them instead, splitting the option
8095 value into ten time slots of equal length.
8096
8097 When memory-depth is 0 and by default this option has no
8098 effect on service failure expiration.
8099
8100 Squid always forgets failures when updating service settings
8101 using an ICAP OPTIONS transaction, regardless of this option
8102 setting.
8103
8104 For example,
8105 # suspend service usage after 10 failures in 5 seconds:
8106 icap_service_failure_limit 10 in 5 seconds
8107DOC_END
8108
8109NAME: icap_service_revival_delay
8110TYPE: int
8111IFDEF: ICAP_CLIENT
8112LOC: Adaptation::Icap::TheConfig.service_revival_delay
8113DEFAULT: 180
8114DOC_START
8115 The delay specifies the number of seconds to wait after an ICAP
8116 OPTIONS request failure before requesting the options again. The
8117 failed ICAP service is considered "down" until fresh OPTIONS are
8118 fetched.
8119
8120 The actual delay cannot be smaller than the hardcoded minimum
8121 delay of 30 seconds.
8122DOC_END
8123
8124NAME: icap_preview_enable
8125TYPE: onoff
8126IFDEF: ICAP_CLIENT
8127COMMENT: on|off
8128LOC: Adaptation::Icap::TheConfig.preview_enable
8129DEFAULT: on
8130DOC_START
8131 The ICAP Preview feature allows the ICAP server to handle the
8132 HTTP message by looking only at the beginning of the message body
8133 or even without receiving the body at all. In some environments,
8134 previews greatly speedup ICAP processing.
8135
8136 During an ICAP OPTIONS transaction, the server may tell Squid what
8137 HTTP messages should be previewed and how big the preview should be.
8138 Squid will not use Preview if the server did not request one.
8139
8140 To disable ICAP Preview for all ICAP services, regardless of
8141 individual ICAP server OPTIONS responses, set this option to "off".
8142Example:
8143icap_preview_enable off
8144DOC_END
8145
8146NAME: icap_preview_size
8147TYPE: int
8148IFDEF: ICAP_CLIENT
8149LOC: Adaptation::Icap::TheConfig.preview_size
8150DEFAULT: -1
8151DEFAULT_DOC: No preview sent.
8152DOC_START
8153 The default size of preview data to be sent to the ICAP server.
8154 This value might be overwritten on a per server basis by OPTIONS requests.
8155DOC_END
8156
8157NAME: icap_206_enable
8158TYPE: onoff
8159IFDEF: ICAP_CLIENT
8160COMMENT: on|off
8161LOC: Adaptation::Icap::TheConfig.allow206_enable
8162DEFAULT: on
8163DOC_START
8164 206 (Partial Content) responses is an ICAP extension that allows the
8165 ICAP agents to optionally combine adapted and original HTTP message
8166 content. The decision to combine is postponed until the end of the
8167 ICAP response. Squid supports Partial Content extension by default.
8168
8169 Activation of the Partial Content extension is negotiated with each
8170 ICAP service during OPTIONS exchange. Most ICAP servers should handle
8171 negotation correctly even if they do not support the extension, but
8172 some might fail. To disable Partial Content support for all ICAP
8173 services and to avoid any negotiation, set this option to "off".
8174
8175 Example:
8176 icap_206_enable off
8177DOC_END
8178
8179NAME: icap_default_options_ttl
8180TYPE: int
8181IFDEF: ICAP_CLIENT
8182LOC: Adaptation::Icap::TheConfig.default_options_ttl
8183DEFAULT: 60
8184DOC_START
8185 The default TTL value for ICAP OPTIONS responses that don't have
8186 an Options-TTL header.
8187DOC_END
8188
8189NAME: icap_persistent_connections
8190TYPE: onoff
8191IFDEF: ICAP_CLIENT
8192COMMENT: on|off
8193LOC: Adaptation::Icap::TheConfig.reuse_connections
8194DEFAULT: on
8195DOC_START
8196 Whether or not Squid should use persistent connections to
8197 an ICAP server.
8198DOC_END
8199
8200NAME: adaptation_send_client_ip icap_send_client_ip
8201TYPE: onoff
8202IFDEF: USE_ADAPTATION
8203COMMENT: on|off
8204LOC: Adaptation::Config::send_client_ip
8205DEFAULT: off
8206DOC_START
8207 If enabled, Squid shares HTTP client IP information with adaptation
8208 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
8209 For eCAP, Squid sets the libecap::metaClientIp transaction option.
8210
8211 See also: adaptation_uses_indirect_client
8212DOC_END
8213
8214NAME: adaptation_send_username icap_send_client_username
8215TYPE: onoff
8216IFDEF: USE_ADAPTATION
8217COMMENT: on|off
8218LOC: Adaptation::Config::send_username
8219DEFAULT: off
8220DOC_START
8221 This sends authenticated HTTP client username (if available) to
8222 the adaptation service.
8223
8224 For ICAP, the username value is encoded based on the
8225 icap_client_username_encode option and is sent using the header
8226 specified by the icap_client_username_header option.
8227DOC_END
8228
8229NAME: icap_client_username_header
8230TYPE: string
8231IFDEF: ICAP_CLIENT
8232LOC: Adaptation::Icap::TheConfig.client_username_header
8233DEFAULT: X-Client-Username
8234DOC_START
8235 ICAP request header name to use for adaptation_send_username.
8236DOC_END
8237
8238NAME: icap_client_username_encode
8239TYPE: onoff
8240IFDEF: ICAP_CLIENT
8241COMMENT: on|off
8242LOC: Adaptation::Icap::TheConfig.client_username_encode
8243DEFAULT: off
8244DOC_START
8245 Whether to base64 encode the authenticated client username.
8246DOC_END
8247
8248NAME: icap_service
8249TYPE: icap_service_type
8250IFDEF: ICAP_CLIENT
8251LOC: Adaptation::Icap::TheConfig
8252DEFAULT: none
8253DOC_START
8254 Defines a single ICAP service using the following format:
8255
8256 icap_service id vectoring_point uri [option ...]
8257
8258 id: ID
8259 an opaque identifier or name which is used to direct traffic to
8260 this specific service. Must be unique among all adaptation
8261 services in squid.conf.
8262
8263 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8264 This specifies at which point of transaction processing the
8265 ICAP service should be activated. *_postcache vectoring points
8266 are not yet supported.
8267
8268 uri: icap://servername:port/servicepath
8269 ICAP server and service location.
8270
8271 ICAP does not allow a single service to handle both REQMOD and RESPMOD
8272 transactions. Squid does not enforce that requirement. You can specify
8273 services with the same service_url and different vectoring_points. You
8274 can even specify multiple identical services as long as their
8275 service_names differ.
8276
8277 To activate a service, use the adaptation_access directive. To group
8278 services, use adaptation_service_chain and adaptation_service_set.
8279
8280 Service options are separated by white space. ICAP services support
8281 the following name=value options:
8282
8283 bypass=on|off|1|0
8284 If set to 'on' or '1', the ICAP service is treated as
8285 optional. If the service cannot be reached or malfunctions,
8286 Squid will try to ignore any errors and process the message as
8287 if the service was not enabled. No all ICAP errors can be
8288 bypassed. If set to 0, the ICAP service is treated as
8289 essential and all ICAP errors will result in an error page
8290 returned to the HTTP client.
8291
8292 Bypass is off by default: services are treated as essential.
8293
8294 routing=on|off|1|0
8295 If set to 'on' or '1', the ICAP service is allowed to
8296 dynamically change the current message adaptation plan by
8297 returning a chain of services to be used next. The services
8298 are specified using the X-Next-Services ICAP response header
8299 value, formatted as a comma-separated list of service names.
8300 Each named service should be configured in squid.conf. Other
8301 services are ignored. An empty X-Next-Services value results
8302 in an empty plan which ends the current adaptation.
8303
8304 Dynamic adaptation plan may cross or cover multiple supported
8305 vectoring points in their natural processing order.
8306
8307 Routing is not allowed by default: the ICAP X-Next-Services
8308 response header is ignored.
8309
8310 ipv6=on|off
8311 Only has effect on split-stack systems. The default on those systems
8312 is to use IPv4-only connections. When set to 'on' this option will
8313 make Squid use IPv6-only connections to contact this ICAP service.
8314
8315 on-overload=block|bypass|wait|force
8316 If the service Max-Connections limit has been reached, do
8317 one of the following for each new ICAP transaction:
8318 * block: send an HTTP error response to the client
8319 * bypass: ignore the "over-connected" ICAP service
8320 * wait: wait (in a FIFO queue) for an ICAP connection slot
8321 * force: proceed, ignoring the Max-Connections limit
8322
8323 In SMP mode with N workers, each worker assumes the service
8324 connection limit is Max-Connections/N, even though not all
8325 workers may use a given service.
8326
8327 The default value is "bypass" if service is bypassable,
8328 otherwise it is set to "wait".
8329
8330
8331 max-conn=number
8332 Use the given number as the Max-Connections limit, regardless
8333 of the Max-Connections value given by the service, if any.
8334
8335 Older icap_service format without optional named parameters is
8336 deprecated but supported for backward compatibility.
8337
8338Example:
8339icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
8340icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
8341DOC_END
8342
8343NAME: icap_class
8344TYPE: icap_class_type
8345IFDEF: ICAP_CLIENT
8346LOC: none
8347DEFAULT: none
8348DOC_START
8349 This deprecated option was documented to define an ICAP service
8350 chain, even though it actually defined a set of similar, redundant
8351 services, and the chains were not supported.
8352
8353 To define a set of redundant services, please use the
8354 adaptation_service_set directive. For service chains, use
8355 adaptation_service_chain.
8356DOC_END
8357
8358NAME: icap_access
8359TYPE: icap_access_type
8360IFDEF: ICAP_CLIENT
8361LOC: none
8362DEFAULT: none
8363DOC_START
8364 This option is deprecated. Please use adaptation_access, which
8365 has the same ICAP functionality, but comes with better
8366 documentation, and eCAP support.
8367DOC_END
8368
8369COMMENT_START
8370 eCAP OPTIONS
8371 -----------------------------------------------------------------------------
8372COMMENT_END
8373
8374NAME: ecap_enable
8375TYPE: onoff
8376IFDEF: USE_ECAP
8377COMMENT: on|off
8378LOC: Adaptation::Ecap::TheConfig.onoff
8379DEFAULT: off
8380DOC_START
8381 Controls whether eCAP support is enabled.
8382DOC_END
8383
8384NAME: ecap_service
8385TYPE: ecap_service_type
8386IFDEF: USE_ECAP
8387LOC: Adaptation::Ecap::TheConfig
8388DEFAULT: none
8389DOC_START
8390 Defines a single eCAP service
8391
8392 ecap_service id vectoring_point uri [option ...]
8393
8394 id: ID
8395 an opaque identifier or name which is used to direct traffic to
8396 this specific service. Must be unique among all adaptation
8397 services in squid.conf.
8398
8399 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8400 This specifies at which point of transaction processing the
8401 eCAP service should be activated. *_postcache vectoring points
8402 are not yet supported.
8403
8404 uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
8405 Squid uses the eCAP service URI to match this configuration
8406 line with one of the dynamically loaded services. Each loaded
8407 eCAP service must have a unique URI. Obtain the right URI from
8408 the service provider.
8409
8410 To activate a service, use the adaptation_access directive. To group
8411 services, use adaptation_service_chain and adaptation_service_set.
8412
8413 Service options are separated by white space. eCAP services support
8414 the following name=value options:
8415
8416 bypass=on|off|1|0
8417 If set to 'on' or '1', the eCAP service is treated as optional.
8418 If the service cannot be reached or malfunctions, Squid will try
8419 to ignore any errors and process the message as if the service
8420 was not enabled. No all eCAP errors can be bypassed.
8421 If set to 'off' or '0', the eCAP service is treated as essential
8422 and all eCAP errors will result in an error page returned to the
8423 HTTP client.
8424
8425 Bypass is off by default: services are treated as essential.
8426
8427 routing=on|off|1|0
8428 If set to 'on' or '1', the eCAP service is allowed to
8429 dynamically change the current message adaptation plan by
8430 returning a chain of services to be used next.
8431
8432 Dynamic adaptation plan may cross or cover multiple supported
8433 vectoring points in their natural processing order.
8434
8435 Routing is not allowed by default.
8436
8437 Older ecap_service format without optional named parameters is
8438 deprecated but supported for backward compatibility.
8439
8440
8441Example:
8442ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
8443ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
8444DOC_END
8445
8446NAME: loadable_modules
8447TYPE: wordlist
8448IFDEF: USE_LOADABLE_MODULES
8449LOC: Config.loadable_module_names
8450DEFAULT: none
8451DOC_START
8452 Instructs Squid to load the specified dynamic module(s) or activate
8453 preloaded module(s).
8454Example:
8455loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
8456DOC_END
8457
8458COMMENT_START
8459 MESSAGE ADAPTATION OPTIONS
8460 -----------------------------------------------------------------------------
8461COMMENT_END
8462
8463NAME: adaptation_service_set
8464TYPE: adaptation_service_set_type
8465IFDEF: USE_ADAPTATION
8466LOC: none
8467DEFAULT: none
8468DOC_START
8469
8470 Configures an ordered set of similar, redundant services. This is
8471 useful when hot standby or backup adaptation servers are available.
8472
8473 adaptation_service_set set_name service_name1 service_name2 ...
8474
8475 The named services are used in the set declaration order. The first
8476 applicable adaptation service from the set is used first. The next
8477 applicable service is tried if and only if the transaction with the
8478 previous service fails and the message waiting to be adapted is still
8479 intact.
8480
8481 When adaptation starts, broken services are ignored as if they were
8482 not a part of the set. A broken service is a down optional service.
8483
8484 The services in a set must be attached to the same vectoring point
8485 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8486
8487 If all services in a set are optional then adaptation failures are
8488 bypassable. If all services in the set are essential, then a
8489 transaction failure with one service may still be retried using
8490 another service from the set, but when all services fail, the master
8491 transaction fails as well.
8492
8493 A set may contain a mix of optional and essential services, but that
8494 is likely to lead to surprising results because broken services become
8495 ignored (see above), making previously bypassable failures fatal.
8496 Technically, it is the bypassability of the last failed service that
8497 matters.
8498
8499 See also: adaptation_access adaptation_service_chain
8500
8501Example:
8502adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
8503adaptation service_set svcLogger loggerLocal loggerRemote
8504DOC_END
8505
8506NAME: adaptation_service_chain
8507TYPE: adaptation_service_chain_type
8508IFDEF: USE_ADAPTATION
8509LOC: none
8510DEFAULT: none
8511DOC_START
8512
8513 Configures a list of complementary services that will be applied
8514 one-by-one, forming an adaptation chain or pipeline. This is useful
8515 when Squid must perform different adaptations on the same message.
8516
8517 adaptation_service_chain chain_name service_name1 svc_name2 ...
8518
8519 The named services are used in the chain declaration order. The first
8520 applicable adaptation service from the chain is used first. The next
8521 applicable service is applied to the successful adaptation results of
8522 the previous service in the chain.
8523
8524 When adaptation starts, broken services are ignored as if they were
8525 not a part of the chain. A broken service is a down optional service.
8526
8527 Request satisfaction terminates the adaptation chain because Squid
8528 does not currently allow declaration of RESPMOD services at the
8529 "reqmod_precache" vectoring point (see icap_service or ecap_service).
8530
8531 The services in a chain must be attached to the same vectoring point
8532 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8533
8534 A chain may contain a mix of optional and essential services. If an
8535 essential adaptation fails (or the failure cannot be bypassed for
8536 other reasons), the master transaction fails. Otherwise, the failure
8537 is bypassed as if the failed adaptation service was not in the chain.
8538
8539 See also: adaptation_access adaptation_service_set
8540
8541Example:
8542adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
8543DOC_END
8544
8545NAME: adaptation_access
8546TYPE: adaptation_access_type
8547IFDEF: USE_ADAPTATION
8548LOC: none
8549DEFAULT: none
8550DEFAULT_DOC: Allow, unless rules exist in squid.conf.
8551DOC_START
8552 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
8553
8554 adaptation_access service_name allow|deny [!]aclname...
8555 adaptation_access set_name allow|deny [!]aclname...
8556
8557 At each supported vectoring point, the adaptation_access
8558 statements are processed in the order they appear in this
8559 configuration file. Statements pointing to the following services
8560 are ignored (i.e., skipped without checking their ACL):
8561
8562 - services serving different vectoring points
8563 - "broken-but-bypassable" services
8564 - "up" services configured to ignore such transactions
8565 (e.g., based on the ICAP Transfer-Ignore header).
8566
8567 When a set_name is used, all services in the set are checked
8568 using the same rules, to find the first applicable one. See
8569 adaptation_service_set for details.
8570
8571 If an access list is checked and there is a match, the
8572 processing stops: For an "allow" rule, the corresponding
8573 adaptation service is used for the transaction. For a "deny"
8574 rule, no adaptation service is activated.
8575
8576 It is currently not possible to apply more than one adaptation
8577 service at the same vectoring point to the same HTTP transaction.
8578
8579 See also: icap_service and ecap_service
8580
8581Example:
8582adaptation_access service_1 allow all
8583DOC_END
8584
8585NAME: adaptation_service_iteration_limit
8586TYPE: int
8587IFDEF: USE_ADAPTATION
8588LOC: Adaptation::Config::service_iteration_limit
8589DEFAULT: 16
8590DOC_START
8591 Limits the number of iterations allowed when applying adaptation
8592 services to a message. If your longest adaptation set or chain
8593 may have more than 16 services, increase the limit beyond its
8594 default value of 16. If detecting infinite iteration loops sooner
8595 is critical, make the iteration limit match the actual number
8596 of services in your longest adaptation set or chain.
8597
8598 Infinite adaptation loops are most likely with routing services.
8599
8600 See also: icap_service routing=1
8601DOC_END
8602
8603NAME: adaptation_masterx_shared_names
8604TYPE: string
8605IFDEF: USE_ADAPTATION
8606LOC: Adaptation::Config::masterx_shared_name
8607DEFAULT: none
8608DOC_START
8609 For each master transaction (i.e., the HTTP request and response
8610 sequence, including all related ICAP and eCAP exchanges), Squid
8611 maintains a table of metadata. The table entries are (name, value)
8612 pairs shared among eCAP and ICAP exchanges. The table is destroyed
8613 with the master transaction.
8614
8615 This option specifies the table entry names that Squid must accept
8616 from and forward to the adaptation transactions.
8617
8618 An ICAP REQMOD or RESPMOD transaction may set an entry in the
8619 shared table by returning an ICAP header field with a name
8620 specified in adaptation_masterx_shared_names.
8621
8622 An eCAP REQMOD or RESPMOD transaction may set an entry in the
8623 shared table by implementing the libecap::visitEachOption() API
8624 to provide an option with a name specified in
8625 adaptation_masterx_shared_names.
8626
8627 Squid will store and forward the set entry to subsequent adaptation
8628 transactions within the same master transaction scope.
8629
8630 Only one shared entry name is supported at this time.
8631
8632Example:
8633# share authentication information among ICAP services
8634adaptation_masterx_shared_names X-Subscriber-ID
8635DOC_END
8636
8637NAME: adaptation_meta
8638TYPE: note
8639IFDEF: USE_ADAPTATION
8640LOC: Adaptation::Config::metaHeaders
8641DEFAULT: none
8642DOC_START
8643 This option allows Squid administrator to add custom ICAP request
8644 headers or eCAP options to Squid ICAP requests or eCAP transactions.
8645 Use it to pass custom authentication tokens and other
8646 transaction-state related meta information to an ICAP/eCAP service.
8647
8648 The addition of a meta header is ACL-driven:
8649 adaptation_meta name value [!]aclname ...
8650
8651 Processing for a given header name stops after the first ACL list match.
8652 Thus, it is impossible to add two headers with the same name. If no ACL
8653 lists match for a given header name, no such header is added. For
8654 example:
8655
8656 # do not debug transactions except for those that need debugging
8657 adaptation_meta X-Debug 1 needs_debugging
8658
8659 # log all transactions except for those that must remain secret
8660 adaptation_meta X-Log 1 !keep_secret
8661
8662 # mark transactions from users in the "G 1" group
8663 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
8664
8665 The "value" parameter may be a regular squid.conf token or a "double
8666 quoted string". Within the quoted string, use backslash (\) to escape
8667 any character, which is currently only useful for escaping backslashes
8668 and double quotes. For example,
8669 "this string has one backslash (\\) and two \"quotes\""
8670
8671 Used adaptation_meta header values may be logged via %note
8672 logformat code. If multiple adaptation_meta headers with the same name
8673 are used during master transaction lifetime, the header values are
8674 logged in the order they were used and duplicate values are ignored
8675 (only the first repeated value will be logged).
8676DOC_END
8677
8678NAME: icap_retry
8679TYPE: acl_access
8680IFDEF: ICAP_CLIENT
8681LOC: Adaptation::Icap::TheConfig.repeat
8682DEFAULT_IF_NONE: deny all
8683DOC_START
8684 This ACL determines which retriable ICAP transactions are
8685 retried. Transactions that received a complete ICAP response
8686 and did not have to consume or produce HTTP bodies to receive
8687 that response are usually retriable.
8688
8689 icap_retry allow|deny [!]aclname ...
8690
8691 Squid automatically retries some ICAP I/O timeouts and errors
8692 due to persistent connection race conditions.
8693
8694 See also: icap_retry_limit
8695DOC_END
8696
8697NAME: icap_retry_limit
8698TYPE: int
8699IFDEF: ICAP_CLIENT
8700LOC: Adaptation::Icap::TheConfig.repeat_limit
8701DEFAULT: 0
8702DEFAULT_DOC: No retries are allowed.
8703DOC_START
8704 Limits the number of retries allowed.
8705
8706 Communication errors due to persistent connection race
8707 conditions are unavoidable, automatically retried, and do not
8708 count against this limit.
8709
8710 See also: icap_retry
8711DOC_END
8712
8713
8714COMMENT_START
8715 DNS OPTIONS
8716 -----------------------------------------------------------------------------
8717COMMENT_END
8718
8719NAME: check_hostnames
8720TYPE: onoff
8721DEFAULT: off
8722LOC: Config.onoff.check_hostnames
8723DOC_START
8724 For security and stability reasons Squid can check
8725 hostnames for Internet standard RFC compliance. If you want
8726 Squid to perform these checks turn this directive on.
8727DOC_END
8728
8729NAME: allow_underscore
8730TYPE: onoff
8731DEFAULT: on
8732LOC: Config.onoff.allow_underscore
8733DOC_START
8734 Underscore characters is not strictly allowed in Internet hostnames
8735 but nevertheless used by many sites. Set this to off if you want
8736 Squid to be strict about the standard.
8737 This check is performed only when check_hostnames is set to on.
8738DOC_END
8739
8740NAME: dns_retransmit_interval
8741TYPE: time_msec
8742DEFAULT: 5 seconds
8743LOC: Config.Timeout.idns_retransmit
8744DOC_START
8745 Initial retransmit interval for DNS queries. The interval is
8746 doubled each time all configured DNS servers have been tried.
8747DOC_END
8748
8749NAME: dns_timeout
8750TYPE: time_msec
8751DEFAULT: 30 seconds
8752LOC: Config.Timeout.idns_query
8753DOC_START
8754 DNS Query timeout. If no response is received to a DNS query
8755 within this time all DNS servers for the queried domain
8756 are assumed to be unavailable.
8757DOC_END
8758
8759NAME: dns_packet_max
8760TYPE: b_ssize_t
8761DEFAULT_DOC: EDNS disabled
8762DEFAULT: none
8763LOC: Config.dns.packet_max
8764DOC_START
8765 Maximum number of bytes packet size to advertise via EDNS.
8766 Set to "none" to disable EDNS large packet support.
8767
8768 For legacy reasons DNS UDP replies will default to 512 bytes which
8769 is too small for many responses. EDNS provides a means for Squid to
8770 negotiate receiving larger responses back immediately without having
8771 to failover with repeat requests. Responses larger than this limit
8772 will retain the old behaviour of failover to TCP DNS.
8773
8774 Squid has no real fixed limit internally, but allowing packet sizes
8775 over 1500 bytes requires network jumbogram support and is usually not
8776 necessary.
8777
8778 WARNING: The RFC also indicates that some older resolvers will reply
8779 with failure of the whole request if the extension is added. Some
8780 resolvers have already been identified which will reply with mangled
8781 EDNS response on occasion. Usually in response to many-KB jumbogram
8782 sizes being advertised by Squid.
8783 Squid will currently treat these both as an unable-to-resolve domain
8784 even if it would be resolvable without EDNS.
8785DOC_END
8786
8787NAME: dns_defnames
8788COMMENT: on|off
8789TYPE: onoff
8790DEFAULT: off
8791DEFAULT_DOC: Search for single-label domain names is disabled.
8792LOC: Config.onoff.res_defnames
8793DOC_START
8794 Normally the RES_DEFNAMES resolver option is disabled
8795 (see res_init(3)). This prevents caches in a hierarchy
8796 from interpreting single-component hostnames locally. To allow
8797 Squid to handle single-component names, enable this option.
8798DOC_END
8799
8800NAME: dns_multicast_local
8801COMMENT: on|off
8802TYPE: onoff
8803DEFAULT: off
8804DEFAULT_DOC: Search for .local and .arpa names is disabled.
8805LOC: Config.onoff.dns_mdns
8806DOC_START
8807 When set to on, Squid sends multicast DNS lookups on the local
8808 network for domains ending in .local and .arpa.
8809 This enables local servers and devices to be contacted in an
8810 ad-hoc or zero-configuration network environment.
8811DOC_END
8812
8813NAME: dns_nameservers
8814TYPE: wordlist
8815DEFAULT: none
8816DEFAULT_DOC: Use operating system definitions
8817LOC: Config.dns_nameservers
8818DOC_START
8819 Use this if you want to specify a list of DNS name servers
8820 (IP addresses) to use instead of those given in your
8821 /etc/resolv.conf file.
8822
8823 On Windows platforms, if no value is specified here or in
8824 the /etc/resolv.conf file, the list of DNS name servers are
8825 taken from the Windows registry, both static and dynamic DHCP
8826 configurations are supported.
8827
8828 Example: dns_nameservers 10.0.0.1 192.172.0.4
8829DOC_END
8830
8831NAME: hosts_file
8832TYPE: string
8833DEFAULT: @DEFAULT_HOSTS@
8834LOC: Config.etcHostsPath
8835DOC_START
8836 Location of the host-local IP name-address associations
8837 database. Most Operating Systems have such a file on different
8838 default locations:
8839 - Un*X & Linux: /etc/hosts
8840 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
8841 (%SystemRoot% value install default is c:\winnt)
8842 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
8843 (%SystemRoot% value install default is c:\windows)
8844 - Windows 9x/Me: %windir%\hosts
8845 (%windir% value is usually c:\windows)
8846 - Cygwin: /etc/hosts
8847
8848 The file contains newline-separated definitions, in the
8849 form ip_address_in_dotted_form name [name ...] names are
8850 whitespace-separated. Lines beginning with an hash (#)
8851 character are comments.
8852
8853 The file is checked at startup and upon configuration.
8854 If set to 'none', it won't be checked.
8855 If append_domain is used, that domain will be added to
8856 domain-local (i.e. not containing any dot character) host
8857 definitions.
8858DOC_END
8859
8860NAME: append_domain
8861TYPE: string
8862LOC: Config.appendDomain
8863DEFAULT: none
8864DEFAULT_DOC: Use operating system definitions
8865DOC_START
8866 Appends local domain name to hostnames without any dots in
8867 them. append_domain must begin with a period.
8868
8869 Be warned there are now Internet names with no dots in
8870 them using only top-domain names, so setting this may
8871 cause some Internet sites to become unavailable.
8872
8873Example:
8874 append_domain .yourdomain.com
8875DOC_END
8876
8877NAME: ignore_unknown_nameservers
8878TYPE: onoff
8879LOC: Config.onoff.ignore_unknown_nameservers
8880DEFAULT: on
8881DOC_START
8882 By default Squid checks that DNS responses are received
8883 from the same IP addresses they are sent to. If they
8884 don't match, Squid ignores the response and writes a warning
8885 message to cache.log. You can allow responses from unknown
8886 nameservers by setting this option to 'off'.
8887DOC_END
8888
8889NAME: dns_v4_first
8890TYPE: onoff
8891DEFAULT: off
8892LOC: Config.dns.v4_first
8893DOC_START
8894 With the IPv6 Internet being as fast or faster than IPv4 Internet
8895 for most networks Squid prefers to contact websites over IPv6.
8896
8897 This option reverses the order of preference to make Squid contact
8898 dual-stack websites over IPv4 first. Squid will still perform both
8899 IPv6 and IPv4 DNS lookups before connecting.
8900
8901 WARNING:
8902 This option will restrict the situations under which IPv6
8903 connectivity is used (and tested). Hiding network problems
8904 which would otherwise be detected and warned about.
8905DOC_END
8906
8907NAME: ipcache_size
8908COMMENT: (number of entries)
8909TYPE: int
8910DEFAULT: 1024
8911LOC: Config.ipcache.size
8912DOC_START
8913 Maximum number of DNS IP cache entries.
8914DOC_END
8915
8916NAME: ipcache_low
8917COMMENT: (percent)
8918TYPE: int
8919DEFAULT: 90
8920LOC: Config.ipcache.low
8921DOC_NONE
8922
8923NAME: ipcache_high
8924COMMENT: (percent)
8925TYPE: int
8926DEFAULT: 95
8927LOC: Config.ipcache.high
8928DOC_START
8929 The size, low-, and high-water marks for the IP cache.
8930DOC_END
8931
8932NAME: fqdncache_size
8933COMMENT: (number of entries)
8934TYPE: int
8935DEFAULT: 1024
8936LOC: Config.fqdncache.size
8937DOC_START
8938 Maximum number of FQDN cache entries.
8939DOC_END
8940
8941COMMENT_START
8942 MISCELLANEOUS
8943 -----------------------------------------------------------------------------
8944COMMENT_END
8945
8946NAME: configuration_includes_quoted_values
8947COMMENT: on|off
8948TYPE: configuration_includes_quoted_values
8949DEFAULT: off
8950LOC: ConfigParser::RecognizeQuotedValues
8951DOC_START
8952 If set, Squid will recognize each "quoted string" after a configuration
8953 directive as a single parameter. The quotes are stripped before the
8954 parameter value is interpreted or used.
8955 See "Values with spaces, quotes, and other special characters"
8956 section for more details.
8957DOC_END
8958
8959NAME: memory_pools
8960COMMENT: on|off
8961TYPE: onoff
8962DEFAULT: on
8963LOC: Config.onoff.mem_pools
8964DOC_START
8965 If set, Squid will keep pools of allocated (but unused) memory
8966 available for future use. If memory is a premium on your
8967 system and you believe your malloc library outperforms Squid
8968 routines, disable this.
8969DOC_END
8970
8971NAME: memory_pools_limit
8972COMMENT: (bytes)
8973TYPE: b_int64_t
8974DEFAULT: 5 MB
8975LOC: Config.MemPools.limit
8976DOC_START
8977 Used only with memory_pools on:
8978 memory_pools_limit 50 MB
8979
8980 If set to a non-zero value, Squid will keep at most the specified
8981 limit of allocated (but unused) memory in memory pools. All free()
8982 requests that exceed this limit will be handled by your malloc
8983 library. Squid does not pre-allocate any memory, just safe-keeps
8984 objects that otherwise would be free()d. Thus, it is safe to set
8985 memory_pools_limit to a reasonably high value even if your
8986 configuration will use less memory.
8987
8988 If set to none, Squid will keep all memory it can. That is, there
8989 will be no limit on the total amount of memory used for safe-keeping.
8990
8991 To disable memory allocation optimization, do not set
8992 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
8993
8994 An overhead for maintaining memory pools is not taken into account
8995 when the limit is checked. This overhead is close to four bytes per
8996 object kept. However, pools may actually _save_ memory because of
8997 reduced memory thrashing in your malloc library.
8998DOC_END
8999
9000NAME: forwarded_for
9001COMMENT: on|off|transparent|truncate|delete
9002TYPE: string
9003DEFAULT: on
9004LOC: opt_forwarded_for
9005DOC_START
9006 If set to "on", Squid will append your client's IP address
9007 in the HTTP requests it forwards. By default it looks like:
9008
9009 X-Forwarded-For: 192.1.2.3
9010
9011 If set to "off", it will appear as
9012
9013 X-Forwarded-For: unknown
9014
9015 If set to "transparent", Squid will not alter the
9016 X-Forwarded-For header in any way.
9017
9018 If set to "delete", Squid will delete the entire
9019 X-Forwarded-For header.
9020
9021 If set to "truncate", Squid will remove all existing
9022 X-Forwarded-For entries, and place the client IP as the sole entry.
9023DOC_END
9024
9025NAME: cachemgr_passwd
9026TYPE: cachemgrpasswd
9027DEFAULT: none
9028DEFAULT_DOC: No password. Actions which require password are denied.
9029LOC: Config.passwd_list
9030DOC_START
9031 Specify passwords for cachemgr operations.
9032
9033 Usage: cachemgr_passwd password action action ...
9034
9035 Some valid actions are (see cache manager menu for a full list):
9036 5min
9037 60min
9038 asndb
9039 authenticator
9040 cbdata
9041 client_list
9042 comm_incoming
9043 config *
9044 counters
9045 delay
9046 digest_stats
9047 dns
9048 events
9049 filedescriptors
9050 fqdncache
9051 histograms
9052 http_headers
9053 info
9054 io
9055 ipcache
9056 mem
9057 menu
9058 netdb
9059 non_peers
9060 objects
9061 offline_toggle *
9062 pconn
9063 peer_select
9064 reconfigure *
9065 redirector
9066 refresh
9067 server_list
9068 shutdown *
9069 store_digest
9070 storedir
9071 utilization
9072 via_headers
9073 vm_objects
9074
9075 * Indicates actions which will not be performed without a
9076 valid password, others can be performed if not listed here.
9077
9078 To disable an action, set the password to "disable".
9079 To allow performing an action without a password, set the
9080 password to "none".
9081
9082 Use the keyword "all" to set the same password for all actions.
9083
9084Example:
9085 cachemgr_passwd secret shutdown
9086 cachemgr_passwd lesssssssecret info stats/objects
9087 cachemgr_passwd disable all
9088DOC_END
9089
9090NAME: client_db
9091COMMENT: on|off
9092TYPE: onoff
9093DEFAULT: on
9094LOC: Config.onoff.client_db
9095DOC_START
9096 If you want to disable collecting per-client statistics,
9097 turn off client_db here.
9098DOC_END
9099
9100NAME: refresh_all_ims
9101COMMENT: on|off
9102TYPE: onoff
9103DEFAULT: off
9104LOC: Config.onoff.refresh_all_ims
9105DOC_START
9106 When you enable this option, squid will always check
9107 the origin server for an update when a client sends an
9108 If-Modified-Since request. Many browsers use IMS
9109 requests when the user requests a reload, and this
9110 ensures those clients receive the latest version.
9111
9112 By default (off), squid may return a Not Modified response
9113 based on the age of the cached version.
9114DOC_END
9115
9116NAME: reload_into_ims
9117IFDEF: USE_HTTP_VIOLATIONS
9118COMMENT: on|off
9119TYPE: onoff
9120DEFAULT: off
9121LOC: Config.onoff.reload_into_ims
9122DOC_START
9123 When you enable this option, client no-cache or ``reload''
9124 requests will be changed to If-Modified-Since requests.
9125 Doing this VIOLATES the HTTP standard. Enabling this
9126 feature could make you liable for problems which it
9127 causes.
9128
9129 see also refresh_pattern for a more selective approach.
9130DOC_END
9131
9132NAME: connect_retries
9133TYPE: int
9134LOC: Config.connect_retries
9135DEFAULT: 0
9136DEFAULT_DOC: Do not retry failed connections.
9137DOC_START
9138 This sets the maximum number of connection attempts made for each
9139 TCP connection. The connect_retries attempts must all still
9140 complete within the connection timeout period.
9141
9142 The default is not to re-try if the first connection attempt fails.
9143 The (not recommended) maximum is 10 tries.
9144
9145 A warning message will be generated if it is set to a too-high
9146 value and the configured value will be over-ridden.
9147
9148 Note: These re-tries are in addition to forward_max_tries
9149 which limit how many different addresses may be tried to find
9150 a useful server.
9151DOC_END
9152
9153NAME: retry_on_error
9154TYPE: onoff
9155LOC: Config.retry.onerror
9156DEFAULT: off
9157DOC_START
9158 If set to ON Squid will automatically retry requests when
9159 receiving an error response with status 403 (Forbidden),
9160 500 (Internal Error), 501 or 503 (Service not available).
9161 Status 502 and 504 (Gateway errors) are always retried.
9162
9163 This is mainly useful if you are in a complex cache hierarchy to
9164 work around access control errors.
9165
9166 NOTE: This retry will attempt to find another working destination.
9167 Which is different from the server which just failed.
9168DOC_END
9169
9170NAME: as_whois_server
9171TYPE: string
9172LOC: Config.as_whois_server
9173DEFAULT: whois.ra.net
9174DOC_START
9175 WHOIS server to query for AS numbers. NOTE: AS numbers are
9176 queried only when Squid starts up, not for every request.
9177DOC_END
9178
9179NAME: offline_mode
9180TYPE: onoff
9181LOC: Config.onoff.offline
9182DEFAULT: off
9183DOC_START
9184 Enable this option and Squid will never try to validate cached
9185 objects.
9186DOC_END
9187
9188NAME: uri_whitespace
9189TYPE: uri_whitespace
9190LOC: Config.uri_whitespace
9191DEFAULT: strip
9192DOC_START
9193 What to do with requests that have whitespace characters in the
9194 URI. Options:
9195
9196 strip: The whitespace characters are stripped out of the URL.
9197 This is the behavior recommended by RFC2396 and RFC3986
9198 for tolerant handling of generic URI.
9199 NOTE: This is one difference between generic URI and HTTP URLs.
9200
9201 deny: The request is denied. The user receives an "Invalid
9202 Request" message.
9203 This is the behaviour recommended by RFC2616 for safe
9204 handling of HTTP request URL.
9205
9206 allow: The request is allowed and the URI is not changed. The
9207 whitespace characters remain in the URI. Note the
9208 whitespace is passed to redirector processes if they
9209 are in use.
9210 Note this may be considered a violation of RFC2616
9211 request parsing where whitespace is prohibited in the
9212 URL field.
9213
9214 encode: The request is allowed and the whitespace characters are
9215 encoded according to RFC1738.
9216
9217 chop: The request is allowed and the URI is chopped at the
9218 first whitespace.
9219
9220
9221 NOTE the current Squid implementation of encode and chop violates
9222 RFC2616 by not using a 301 redirect after altering the URL.
9223DOC_END
9224
9225NAME: chroot
9226TYPE: string
9227LOC: Config.chroot_dir
9228DEFAULT: none
9229DOC_START
9230 Specifies a directory where Squid should do a chroot() while
9231 initializing. This also causes Squid to fully drop root
9232 privileges after initializing. This means, for example, if you
9233 use a HTTP port less than 1024 and try to reconfigure, you may
9234 get an error saying that Squid can not open the port.
9235DOC_END
9236
9237NAME: balance_on_multiple_ip
9238TYPE: onoff
9239LOC: Config.onoff.balance_on_multiple_ip
9240DEFAULT: off
9241DOC_START
9242 Modern IP resolvers in squid sort lookup results by preferred access.
9243 By default squid will use these IP in order and only rotates to
9244 the next listed when the most preffered fails.
9245
9246 Some load balancing servers based on round robin DNS have been
9247 found not to preserve user session state across requests
9248 to different IP addresses.
9249
9250 Enabling this directive Squid rotates IP's per request.
9251DOC_END
9252
9253NAME: pipeline_prefetch
9254TYPE: pipelinePrefetch
9255LOC: Config.pipeline_max_prefetch
9256DEFAULT: 0
9257DEFAULT_DOC: Do not pre-parse pipelined requests.
9258DOC_START
9259 HTTP clients may send a pipeline of 1+N requests to Squid using a
9260 single connection, without waiting for Squid to respond to the first
9261 of those requests. This option limits the number of concurrent
9262 requests Squid will try to handle in parallel. If set to N, Squid
9263 will try to receive and process up to 1+N requests on the same
9264 connection concurrently.
9265
9266 Defaults to 0 (off) for bandwidth management and access logging
9267 reasons.
9268
9269 NOTE: pipelining requires persistent connections to clients.
9270
9271 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
9272DOC_END
9273
9274NAME: high_response_time_warning
9275TYPE: int
9276COMMENT: (msec)
9277LOC: Config.warnings.high_rptm
9278DEFAULT: 0
9279DEFAULT_DOC: disabled.
9280DOC_START
9281 If the one-minute median response time exceeds this value,
9282 Squid prints a WARNING with debug level 0 to get the
9283 administrators attention. The value is in milliseconds.
9284DOC_END
9285
9286NAME: high_page_fault_warning
9287TYPE: int
9288LOC: Config.warnings.high_pf
9289DEFAULT: 0
9290DEFAULT_DOC: disabled.
9291DOC_START
9292 If the one-minute average page fault rate exceeds this
9293 value, Squid prints a WARNING with debug level 0 to get
9294 the administrators attention. The value is in page faults
9295 per second.
9296DOC_END
9297
9298NAME: high_memory_warning
9299TYPE: b_size_t
9300LOC: Config.warnings.high_memory
9301IFDEF: HAVE_MSTATS&&HAVE_GNUMALLOC_H
9302DEFAULT: 0 KB
9303DEFAULT_DOC: disabled.
9304DOC_START
9305 If the memory usage (as determined by gnumalloc, if available and used)
9306 exceeds this amount, Squid prints a WARNING with debug level 0 to get
9307 the administrators attention.
9308DOC_END
9309# TODO: link high_memory_warning to mempools?
9310
9311NAME: sleep_after_fork
9312COMMENT: (microseconds)
9313TYPE: int
9314LOC: Config.sleep_after_fork
9315DEFAULT: 0
9316DOC_START
9317 When this is set to a non-zero value, the main Squid process
9318 sleeps the specified number of microseconds after a fork()
9319 system call. This sleep may help the situation where your
9320 system reports fork() failures due to lack of (virtual)
9321 memory. Note, however, if you have a lot of child
9322 processes, these sleep delays will add up and your
9323 Squid will not service requests for some amount of time
9324 until all the child processes have been started.
9325 On Windows value less then 1000 (1 milliseconds) are
9326 rounded to 1000.
9327DOC_END
9328
9329NAME: windows_ipaddrchangemonitor
9330IFDEF: _SQUID_WINDOWS_
9331COMMENT: on|off
9332TYPE: onoff
9333DEFAULT: on
9334LOC: Config.onoff.WIN32_IpAddrChangeMonitor
9335DOC_START
9336 On Windows Squid by default will monitor IP address changes and will
9337 reconfigure itself after any detected event. This is very useful for
9338 proxies connected to internet with dial-up interfaces.
9339 In some cases (a Proxy server acting as VPN gateway is one) it could be
9340 desiderable to disable this behaviour setting this to 'off'.
9341 Note: after changing this, Squid service must be restarted.
9342DOC_END
9343
9344NAME: eui_lookup
9345TYPE: onoff
9346IFDEF: USE_SQUID_EUI
9347DEFAULT: on
9348LOC: Eui::TheConfig.euiLookup
9349DOC_START
9350 Whether to lookup the EUI or MAC address of a connected client.
9351DOC_END
9352
9353NAME: max_filedescriptors max_filedesc
9354TYPE: int
9355DEFAULT: 0
9356DEFAULT_DOC: Use operating system limits set by ulimit.
9357LOC: Config.max_filedescriptors
9358DOC_START
9359 Reduce the maximum number of filedescriptors supported below
9360 the usual operating system defaults.
9361
9362 Remove from squid.conf to inherit the current ulimit setting.
9363
9364 Note: Changing this requires a restart of Squid. Also
9365 not all I/O types supports large values (eg on Windows).
9366DOC_END
9367
9368NAME: workers
9369TYPE: int
9370LOC: Config.workers
9371DEFAULT: 1
9372DEFAULT_DOC: SMP support disabled.
9373DOC_START
9374 Number of main Squid processes or "workers" to fork and maintain.
9375 0: "no daemon" mode, like running "squid -N ..."
9376 1: "no SMP" mode, start one main Squid process daemon (default)
9377 N: start N main Squid process daemons (i.e., SMP mode)
9378
9379 In SMP mode, each worker does nearly all what a single Squid daemon
9380 does (e.g., listen on http_port and forward HTTP requests).
9381DOC_END
9382
9383NAME: cpu_affinity_map
9384TYPE: CpuAffinityMap
9385LOC: Config.cpuAffinityMap
9386DEFAULT: none
9387DEFAULT_DOC: Let operating system decide.
9388DOC_START
9389 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
9390
9391 Sets 1:1 mapping between Squid processes and CPU cores. For example,
9392
9393 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
9394
9395 affects processes 1 through 4 only and places them on the first
9396 four even cores, starting with core #1.
9397
9398 CPU cores are numbered starting from 1. Requires support for
9399 sched_getaffinity(2) and sched_setaffinity(2) system calls.
9400
9401 Multiple cpu_affinity_map options are merged.
9402
9403 See also: workers
9404DOC_END
9405
9406NAME: force_request_body_continuation
9407TYPE: acl_access
9408LOC: Config.accessList.forceRequestBodyContinuation
9409DEFAULT: none
9410DEFAULT_DOC: Deny, unless rules exist in squid.conf.
9411DOC_START
9412 This option controls how Squid handles data upload requests from HTTP
9413 and FTP agents that require a "Please Continue" control message response
9414 to actually send the request body to Squid. It is mostly useful in
9415 adaptation environments.
9416
9417 When Squid receives an HTTP request with an "Expect: 100-continue"
9418 header or an FTP upload command (e.g., STOR), Squid normally sends the
9419 request headers or FTP command information to an adaptation service (or
9420 peer) and waits for a response. Most adaptation services (and some
9421 broken peers) may not respond to Squid at that stage because they may
9422 decide to wait for the HTTP request body or FTP data transfer. However,
9423 that request body or data transfer may never come because Squid has not
9424 responded with the HTTP 100 or FTP 150 (Please Continue) control message
9425 to the request sender yet!
9426
9427 An allow match tells Squid to respond with the HTTP 100 or FTP 150
9428 (Please Continue) control message on its own, before forwarding the
9429 request to an adaptation service or peer. Such a response usually forces
9430 the request sender to proceed with sending the body. A deny match tells
9431 Squid to delay that control response until the origin server confirms
9432 that the request body is needed. Delaying is the default behavior.
9433DOC_END
9434
9435EOF