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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
68 Conditional configuration
69
70 If-statements can be used to make configuration directives
71 depend on conditions:
72
73 if <CONDITION>
74 ... regular configuration directives ...
75 [else
76 ... regular configuration directives ...]
77 endif
78
79 The else part is optional. The keywords "if", "else", and "endif"
80 must be typed on their own lines, as if they were regular
81 configuration directives.
82
83 NOTE: An else-if condition is not supported.
84
85 These individual conditions types are supported:
86
87 true
88 Always evaluates to true.
89 false
90 Always evaluates to false.
91 <integer> = <integer>
92 Equality comparison of two integer numbers.
93
94
95 SMP-Related Macros
96
97 The following SMP-related preprocessor macros can be used.
98
99 ${process_name} expands to the current Squid process "name"
100 (e.g., squid1, squid2, or cache1).
101
102 ${process_number} expands to the current Squid process
103 identifier, which is an integer number (e.g., 1, 2, 3) unique
104 across all Squid processes.
105COMMENT_END
106
107# options still not yet ported from 2.7 to 3.x
108NAME: broken_vary_encoding
109TYPE: obsolete
110DOC_START
111 This option is not yet supported by Squid-3.
112DOC_END
113
114NAME: cache_vary
115TYPE: obsolete
116DOC_START
117 This option is not yet supported by Squid-3.
118DOC_END
119
120NAME: collapsed_forwarding
121TYPE: obsolete
122DOC_START
123 This option is not yet supported by Squid-3. see http://bugs.squid-cache.org/show_bug.cgi?id=3495
124DOC_END
125
126NAME: error_map
127TYPE: obsolete
128DOC_START
129 This option is not yet supported by Squid-3.
130DOC_END
131
132NAME: external_refresh_check
133TYPE: obsolete
134DOC_START
135 This option is not yet supported by Squid-3.
136DOC_END
137
138NAME: ignore_ims_on_miss
139TYPE: obsolete
140DOC_START
141 This option is not yet supported by Squid-3.
142DOC_END
143
144NAME: location_rewrite_program location_rewrite_access location_rewrite_children location_rewrite_concurrency
145TYPE: obsolete
146DOC_START
147 This option is not yet supported by Squid-3.
148DOC_END
149
150NAME: refresh_stale_hit
151TYPE: obsolete
152DOC_START
153 This option is not yet supported by Squid-3.
154DOC_END
155
156# no Options Removed in 3.3
157
158# Options Removed in 3.2
159NAME: ignore_expect_100
160TYPE: obsolete
161DOC_START
162 Remove this line. The HTTP/1.1 feature is now fully supported by default.
163DOC_END
164
165NAME: dns_v4_fallback
166TYPE: obsolete
167DOC_START
168 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
169DOC_END
170
171NAME: ftp_list_width
172TYPE: obsolete
173DOC_START
174 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
175DOC_END
176
177NAME: maximum_single_addr_tries
178TYPE: obsolete
179DOC_START
180 Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
181DOC_END
182
183NAME: update_headers
184TYPE: obsolete
185DOC_START
186 Remove this line. The feature is supported by default in storage types where update is implemented.
187DOC_END
188
189NAME: url_rewrite_concurrency
190TYPE: obsolete
191DOC_START
192 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
193DOC_END
194
195# Options Removed in 3.1
196NAME: dns_testnames
197TYPE: obsolete
198DOC_START
199 Remove this line. DNS is no longer tested on startup.
200DOC_END
201
202NAME: extension_methods
203TYPE: obsolete
204DOC_START
205 Remove this line. All valid methods for HTTP are accepted by default.
206DOC_END
207
208# 2.7 Options Removed/Replaced in 3.2
209NAME: zero_buffers
210TYPE: obsolete
211DOC_NONE
212
213# 2.7 Options Removed/Replaced in 3.1
214NAME: incoming_rate
215TYPE: obsolete
216DOC_NONE
217
218NAME: server_http11
219TYPE: obsolete
220DOC_START
221 Remove this line. HTTP/1.1 is supported by default.
222DOC_END
223
224NAME: upgrade_http0.9
225TYPE: obsolete
226DOC_START
227 Remove this line. ICY/1.0 streaming protocol is supported by default.
228DOC_END
229
230NAME: zph_local zph_mode zph_option zph_parent zph_sibling
231TYPE: obsolete
232DOC_START
233 Alter these entries. Use the qos_flows directive instead.
234DOC_END
235
236# Options Removed in 3.0
237NAME: header_access
238TYPE: obsolete
239DOC_START
240 Since squid-3.0 replace with request_header_access or reply_header_access
241 depending on whether you wish to match client requests or server replies.
242DOC_END
243
244NAME: httpd_accel_no_pmtu_disc
245TYPE: obsolete
246DOC_START
247 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
248DOC_END
249
250NAME: wais_relay_host
251TYPE: obsolete
252DOC_START
253 Replace this line with 'cache_peer' configuration.
254DOC_END
255
256NAME: wais_relay_port
257TYPE: obsolete
258DOC_START
259 Replace this line with 'cache_peer' configuration.
260DOC_END
261
262COMMENT_START
263 OPTIONS FOR AUTHENTICATION
264 -----------------------------------------------------------------------------
265COMMENT_END
266
267NAME: auth_param
268TYPE: authparam
269IFDEF: USE_AUTH
270LOC: Auth::TheConfig
271DEFAULT: none
272DOC_START
273 This is used to define parameters for the various authentication
274 schemes supported by Squid.
275
276 format: auth_param scheme parameter [setting]
277
278 The order in which authentication schemes are presented to the client is
279 dependent on the order the scheme first appears in config file. IE
280 has a bug (it's not RFC 2617 compliant) in that it will use the basic
281 scheme if basic is the first entry presented, even if more secure
282 schemes are presented. For now use the order in the recommended
283 settings section below. If other browsers have difficulties (don't
284 recognize the schemes offered even if you are using basic) either
285 put basic first, or disable the other schemes (by commenting out their
286 program entry).
287
288 Once an authentication scheme is fully configured, it can only be
289 shutdown by shutting squid down and restarting. Changes can be made on
290 the fly and activated with a reconfigure. I.E. You can change to a
291 different helper, but not unconfigure the helper completely.
292
293 Please note that while this directive defines how Squid processes
294 authentication it does not automatically activate authentication.
295 To use authentication you must in addition make use of ACLs based
296 on login name in http_access (proxy_auth, proxy_auth_regex or
297 external with %LOGIN used in the format tag). The browser will be
298 challenged for authentication on the first such acl encountered
299 in http_access processing and will also be re-challenged for new
300 login credentials if the request is being denied by a proxy_auth
301 type acl.
302
303 WARNING: authentication can't be used in a transparently intercepting
304 proxy as the client then thinks it is talking to an origin server and
305 not the proxy. This is a limitation of bending the TCP/IP protocol to
306 transparently intercepting port 80, not a limitation in Squid.
307 Ports flagged 'transparent', 'intercept', or 'tproxy' have
308 authentication disabled.
309
310 === Parameters for the basic scheme follow. ===
311
312 "program" cmdline
313 Specify the command for the external authenticator. Such a program
314 reads a line containing "username password" and replies with one of
315 three results:
316
317 OK
318 the user exists.
319
320 ERR
321 the user does not exist.
322
323 BH
324 An internal error occurred in the helper, preventing
325 a result being identified.
326
327 "ERR" and "BH" results may optionally be followed by message="..."
328 containing a description available as %m in the returned error page.
329
330 If you use an authenticator, make sure you have 1 acl of type
331 proxy_auth.
332
333 By default, the basic authentication scheme is not used unless a
334 program is specified.
335
336 If you want to use the traditional NCSA proxy authentication, set
337 this line to something like
338
339 auth_param basic program @DEFAULT_PREFIX@/libexec/basic_ncsa_auth @DEFAULT_PREFIX@/etc/passwd
340
341 "utf8" on|off
342 HTTP uses iso-latin-1 as character set, while some authentication
343 backends such as LDAP expects UTF-8. If this is set to on Squid will
344 translate the HTTP iso-latin-1 charset to UTF-8 before sending the
345 username & password to the helper.
346
347 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
348 The maximum number of authenticator processes to spawn. If you start too few
349 Squid will have to wait for them to process a backlog of credential
350 verifications, slowing it down. When password verifications are
351 done via a (slow) network you are likely to need lots of
352 authenticator processes.
353
354 The startup= and idle= options permit some skew in the exact amount
355 run. A minimum of startup=N will begin during startup and reconfigure.
356 Squid will start more in groups of up to idle=N in an attempt to meet
357 traffic needs and to keep idle=N free above those traffic needs up to
358 the maximum.
359
360 The concurrency= option sets the number of concurrent requests the
361 helper can process. The default of 0 is used for helpers who only
362 supports one request at a time. Setting this to a number greater than
363 0 changes the protocol used to include a channel number first on the
364 request/response line, allowing multiple requests to be sent to the
365 same helper in parallel without waiting for the response.
366 Must not be set unless it's known the helper supports this.
367
368 auth_param basic children 20 startup=0 idle=1
369
370 "realm" realmstring
371 Specifies the realm name which is to be reported to the
372 client for the basic proxy authentication scheme (part of
373 the text the user will see when prompted their username and
374 password). There is no default.
375 auth_param basic realm Squid proxy-caching web server
376
377 "credentialsttl" timetolive
378 Specifies how long squid assumes an externally validated
379 username:password pair is valid for - in other words how
380 often the helper program is called for that user. Set this
381 low to force revalidation with short lived passwords. Note
382 setting this high does not impact your susceptibility
383 to replay attacks unless you are using an one-time password
384 system (such as SecureID). If you are using such a system,
385 you will be vulnerable to replay attacks unless you also
386 use the max_user_ip ACL in an http_access rule.
387
388 "casesensitive" on|off
389 Specifies if usernames are case sensitive. Most user databases are
390 case insensitive allowing the same username to be spelled using both
391 lower and upper case letters, but some are case sensitive. This
392 makes a big difference for user_max_ip ACL processing and similar.
393 auth_param basic casesensitive off
394
395 === Parameters for the digest scheme follow ===
396
397 "program" cmdline
398 Specify the command for the external authenticator. Such
399 a program reads a line containing "username":"realm" and
400 replies with one of three results:
401
402 OK ha1="..."
403 the user exists. The ha1= key is mandatory and
404 contains the appropriate H(A1) value, hex encoded.
405 See rfc 2616 for the definition of H(A1).
406
407 ERR
408 the user does not exist.
409
410 BH
411 An internal error occurred in the helper, preventing
412 a result being identified.
413
414 "ERR" and "BH" results may optionally be followed by message="..."
415 containing a description available as %m in the returned error page.
416
417 By default, the digest authentication scheme is not used unless a
418 program is specified.
419
420 If you want to use a digest authenticator, set this line to
421 something like
422
423 auth_param digest program @DEFAULT_PREFIX@/bin/digest_pw_auth @DEFAULT_PREFIX@/etc/digpass
424
425 "utf8" on|off
426 HTTP uses iso-latin-1 as character set, while some authentication
427 backends such as LDAP expects UTF-8. If this is set to on Squid will
428 translate the HTTP iso-latin-1 charset to UTF-8 before sending the
429 username & password to the helper.
430
431 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
432 The maximum number of authenticator processes to spawn (default 5).
433 If you start too few Squid will have to wait for them to
434 process a backlog of H(A1) calculations, slowing it down.
435 When the H(A1) calculations are done via a (slow) network
436 you are likely to need lots of authenticator processes.
437
438 The startup= and idle= options permit some skew in the exact amount
439 run. A minimum of startup=N will begin during startup and reconfigure.
440 Squid will start more in groups of up to idle=N in an attempt to meet
441 traffic needs and to keep idle=N free above those traffic needs up to
442 the maximum.
443
444 The concurrency= option sets the number of concurrent requests the
445 helper can process. The default of 0 is used for helpers who only
446 supports one request at a time. Setting this to a number greater than
447 0 changes the protocol used to include a channel number first on the
448 request/response line, allowing multiple requests to be sent to the
449 same helper in parallel without waiting for the response.
450 Must not be set unless it's known the helper supports this.
451
452 auth_param digest children 20 startup=0 idle=1
453
454 "realm" realmstring
455 Specifies the realm name which is to be reported to the
456 client for the digest proxy authentication scheme (part of
457 the text the user will see when prompted their username and
458 password). There is no default.
459 auth_param digest realm Squid proxy-caching web server
460
461 "nonce_garbage_interval" timeinterval
462 Specifies the interval that nonces that have been issued
463 to client_agent's are checked for validity.
464
465 "nonce_max_duration" timeinterval
466 Specifies the maximum length of time a given nonce will be
467 valid for.
468
469 "nonce_max_count" number
470 Specifies the maximum number of times a given nonce can be
471 used.
472
473 "nonce_strictness" on|off
474 Determines if squid requires strict increment-by-1 behavior
475 for nonce counts, or just incrementing (off - for use when
476 user agents generate nonce counts that occasionally miss 1
477 (ie, 1,2,4,6)). Default off.
478
479 "check_nonce_count" on|off
480 This directive if set to off can disable the nonce count check
481 completely to work around buggy digest qop implementations in
482 certain mainstream browser versions. Default on to check the
483 nonce count to protect from authentication replay attacks.
484
485 "post_workaround" on|off
486 This is a workaround to certain buggy browsers who sends
487 an incorrect request digest in POST requests when reusing
488 the same nonce as acquired earlier on a GET request.
489
490 === NTLM scheme options follow ===
491
492 "program" cmdline
493 Specify the command for the external NTLM authenticator.
494 Such a program reads exchanged NTLMSSP packets with
495 the browser via Squid until authentication is completed.
496 If you use an NTLM authenticator, make sure you have 1 acl
497 of type proxy_auth. By default, the NTLM authenticator program
498 is not used.
499
500 auth_param ntlm program /usr/bin/ntlm_auth
501
502 "children" numberofchildren [startup=N] [idle=N]
503 The maximum number of authenticator processes to spawn (default 5).
504 If you start too few Squid will have to wait for them to
505 process a backlog of credential verifications, slowing it
506 down. When credential verifications are done via a (slow)
507 network you are likely to need lots of authenticator
508 processes.
509
510 The startup= and idle= options permit some skew in the exact amount
511 run. A minimum of startup=N will begin during startup and reconfigure.
512 Squid will start more in groups of up to idle=N in an attempt to meet
513 traffic needs and to keep idle=N free above those traffic needs up to
514 the maximum.
515
516 auth_param ntlm children 20 startup=0 idle=1
517
518 "keep_alive" on|off
519 If you experience problems with PUT/POST requests when using the
520 Negotiate authentication scheme then you can try setting this to
521 off. This will cause Squid to forcibly close the connection on
522 the initial requests where the browser asks which schemes are
523 supported by the proxy.
524
525 auth_param ntlm keep_alive on
526
527 === Options for configuring the NEGOTIATE auth-scheme follow ===
528
529 "program" cmdline
530 Specify the command for the external Negotiate authenticator.
531 This protocol is used in Microsoft Active-Directory enabled setups with
532 the Microsoft Internet Explorer or Mozilla Firefox browsers.
533 Its main purpose is to exchange credentials with the Squid proxy
534 using the Kerberos mechanisms.
535 If you use a Negotiate authenticator, make sure you have at least
536 one acl of type proxy_auth active. By default, the negotiate
537 authenticator program is not used.
538 The only supported program for this role is the ntlm_auth
539 program distributed as part of Samba, version 4 or later.
540
541 auth_param negotiate program /usr/bin/ntlm_auth --helper-protocol=gss-spnego
542
543 "children" numberofchildren [startup=N] [idle=N]
544 The maximum number of authenticator processes to spawn (default 5).
545 If you start too few Squid will have to wait for them to
546 process a backlog of credential verifications, slowing it
547 down. When credential verifications are done via a (slow)
548 network you are likely to need lots of authenticator
549 processes.
550
551 The startup= and idle= options permit some skew in the exact amount
552 run. A minimum of startup=N will begin during startup and reconfigure.
553 Squid will start more in groups of up to idle=N in an attempt to meet
554 traffic needs and to keep idle=N free above those traffic needs up to
555 the maximum.
556
557 auth_param negotiate children 20 startup=0 idle=1
558
559 "keep_alive" on|off
560 If you experience problems with PUT/POST requests when using the
561 Negotiate authentication scheme then you can try setting this to
562 off. This will cause Squid to forcibly close the connection on
563 the initial requests where the browser asks which schemes are
564 supported by the proxy.
565
566 auth_param negotiate keep_alive on
567
568
569 Examples:
570
571#Recommended minimum configuration per scheme:
572#auth_param negotiate program <uncomment and complete this line to activate>
573#auth_param negotiate children 20 startup=0 idle=1
574#auth_param negotiate keep_alive on
575#
576#auth_param ntlm program <uncomment and complete this line to activate>
577#auth_param ntlm children 20 startup=0 idle=1
578#auth_param ntlm keep_alive on
579#
580#auth_param digest program <uncomment and complete this line>
581#auth_param digest children 20 startup=0 idle=1
582#auth_param digest realm Squid proxy-caching web server
583#auth_param digest nonce_garbage_interval 5 minutes
584#auth_param digest nonce_max_duration 30 minutes
585#auth_param digest nonce_max_count 50
586#
587#auth_param basic program <uncomment and complete this line>
588#auth_param basic children 5 startup=5 idle=1
589#auth_param basic realm Squid proxy-caching web server
590#auth_param basic credentialsttl 2 hours
591DOC_END
592
593NAME: authenticate_cache_garbage_interval
594TYPE: time_t
595DEFAULT: 1 hour
596LOC: Config.authenticateGCInterval
597DOC_START
598 The time period between garbage collection across the username cache.
599 This is a trade-off between memory utilization (long intervals - say
600 2 days) and CPU (short intervals - say 1 minute). Only change if you
601 have good reason to.
602DOC_END
603
604NAME: authenticate_ttl
605TYPE: time_t
606DEFAULT: 1 hour
607LOC: Config.authenticateTTL
608DOC_START
609 The time a user & their credentials stay in the logged in
610 user cache since their last request. When the garbage
611 interval passes, all user credentials that have passed their
612 TTL are removed from memory.
613DOC_END
614
615NAME: authenticate_ip_ttl
616TYPE: time_t
617LOC: Config.authenticateIpTTL
618DEFAULT: 1 second
619DOC_START
620 If you use proxy authentication and the 'max_user_ip' ACL,
621 this directive controls how long Squid remembers the IP
622 addresses associated with each user. Use a small value
623 (e.g., 60 seconds) if your users might change addresses
624 quickly, as is the case with dialup. You might be safe
625 using a larger value (e.g., 2 hours) in a corporate LAN
626 environment with relatively static address assignments.
627DOC_END
628
629COMMENT_START
630 ACCESS CONTROLS
631 -----------------------------------------------------------------------------
632COMMENT_END
633
634NAME: external_acl_type
635TYPE: externalAclHelper
636LOC: Config.externalAclHelperList
637DEFAULT: none
638DOC_START
639 This option defines external acl classes using a helper program
640 to look up the status
641
642 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
643
644 Options:
645
646 ttl=n TTL in seconds for cached results (defaults to 3600
647 for 1 hour)
648 negative_ttl=n
649 TTL for cached negative lookups (default same
650 as ttl)
651 children-max=n
652 Maximum number of acl helper processes spawned to service
653 external acl lookups of this type. (default 20)
654 children-startup=n
655 Minimum number of acl helper processes to spawn during
656 startup and reconfigure to service external acl lookups
657 of this type. (default 0)
658 children-idle=n
659 Number of acl helper processes to keep ahead of traffic
660 loads. Squid will spawn this many at once whenever load
661 rises above the capabilities of existing processes.
662 Up to the value of children-max. (default 1)
663 concurrency=n concurrency level per process. Only used with helpers
664 capable of processing more than one query at a time.
665 cache=n limit the result cache size, default is unbounded.
666 grace=n Percentage remaining of TTL where a refresh of a
667 cached entry should be initiated without needing to
668 wait for a new reply. (default is for no grace period)
669 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
670 ipv4 / ipv6 IP protocol used to communicate with this helper.
671 The default is to auto-detect IPv6 and use it when available.
672
673 FORMAT specifications
674
675 %LOGIN Authenticated user login name
676 %EXT_USER Username from previous external acl
677 %EXT_LOG Log details from previous external acl
678 %EXT_TAG Tag from previous external acl
679 %IDENT Ident user name
680 %SRC Client IP
681 %SRCPORT Client source port
682 %URI Requested URI
683 %DST Requested host
684 %PROTO Requested protocol
685 %PORT Requested port
686 %PATH Requested URL path
687 %METHOD Request method
688 %MYADDR Squid interface address
689 %MYPORT Squid http_port number
690 %PATH Requested URL-path (including query-string if any)
691 %USER_CERT SSL User certificate in PEM format
692 %USER_CERTCHAIN SSL User certificate chain in PEM format
693 %USER_CERT_xx SSL User certificate subject attribute xx
694 %USER_CA_xx SSL User certificate issuer attribute xx
695
696 %>{Header} HTTP request header "Header"
697 %>{Hdr:member}
698 HTTP request header "Hdr" list member "member"
699 %>{Hdr:;member}
700 HTTP request header list member using ; as
701 list separator. ; can be any non-alphanumeric
702 character.
703
704 %<{Header} HTTP reply header "Header"
705 %<{Hdr:member}
706 HTTP reply header "Hdr" list member "member"
707 %<{Hdr:;member}
708 HTTP reply header list member using ; as
709 list separator. ; can be any non-alphanumeric
710 character.
711
712 %% The percent sign. Useful for helpers which need
713 an unchanging input format.
714
715
716 General request syntax:
717
718 [channel-ID] FORMAT-values [acl-values ...]
719
720
721 FORMAT-values consists of transaction details expanded with
722 whitespace separation per the config file FORMAT specification
723 using the FORMAT macros listed above.
724
725 acl-values consists of any string specified in the referencing
726 config 'acl ... external' line. see the "acl external" directive.
727
728 Request values sent to the helper are URL escaped to protect
729 each value in requests against whitespaces.
730
731 If using protocol=2.5 then the request sent to the helper is not
732 URL escaped to protect against whitespace.
733
734 NOTE: protocol=3.0 is deprecated as no longer necessary.
735
736 When using the concurrency= option the protocol is changed by
737 introducing a query channel tag in front of the request/response.
738 The query channel tag is a number between 0 and concurrency-1.
739 This value must be echoed back unchanged to Squid as the first part
740 of the response relating to its request.
741
742
743 The helper receives lines expanded per the above format specification
744 and for each input line returns 1 line starting with OK/ERR/BH result
745 code and optionally followed by additional keywords with more details.
746
747
748 General result syntax:
749
750 [channel-ID] result keyword=value ...
751
752 Result consists of one of the codes:
753
754 OK
755 the ACL test produced a match.
756
757 ERR
758 the ACL test does not produce a match.
759
760 BH
761 An internal error occurred in the helper, preventing
762 a result being identified.
763
764 The meaning of 'a match' is determined by your squid.conf
765 access control configuration. See the Squid wiki for details.
766
767 Defined keywords:
768
769 user= The users name (login)
770
771 password= The users password (for login= cache_peer option)
772
773 message= Message describing the reason for this response.
774 Available as %o in error pages.
775 Useful on (ERR and BH results).
776
777 tag= Apply a tag to a request. Only sets a tag once,
778 does not alter existing tags.
779
780 log= String to be logged in access.log. Available as
781 %ea in logformat specifications.
782
783 Any keywords may be sent on any response whether OK, ERR or BH.
784
785 All response keyword values need to be a single token with URL
786 escaping, or enclosed in double quotes (") and escaped using \ on
787 any double quotes or \ characters within the value. The wrapping
788 double quotes are removed before the value is interpreted by Squid.
789 \r and \n are also replace by CR and LF.
790
791 Some example key values:
792
793 user=John%20Smith
794 user="John Smith"
795 user="J. \"Bob\" Smith"
796DOC_END
797
798NAME: acl
799TYPE: acl
800LOC: Config.aclList
801IF USE_SSL
802DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
803DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
804DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
805DEFAULT: 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
806DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
807ENDIF
808DEFAULT: all src all
809DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
810DEFAULT: localhost src 127.0.0.1/32 ::1
811DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
812DEFAULT_DOC: ACLs all, manager, localhost, and to_localhost are predefined.
813DOC_START
814 Defining an Access List
815
816 Every access list definition must begin with an aclname and acltype,
817 followed by either type-specific arguments or a quoted filename that
818 they are read from.
819
820 acl aclname acltype argument ...
821 acl aclname acltype "file" ...
822
823 When using "file", the file should contain one item per line.
824
825 Some acl types supports options which changes their default behaviour.
826 The available options are:
827
828 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
829 case-insensitive, use the -i option. To return case-sensitive
830 use the +i option between patterns, or make a new ACL line
831 without -i.
832
833 -n Disable lookups and address type conversions. If lookup or
834 conversion is required because the parameter type (IP or
835 domain name) does not match the message address type (domain
836 name or IP), then the ACL would immediately declare a mismatch
837 without any warnings or lookups.
838
839 -- Used to stop processing all options, in the case the first acl
840 value has '-' character as first character (for example the '-'
841 is a valid domain name)
842
843 Some acl types require suspending the current request in order
844 to access some external data source.
845 Those which do are marked with the tag [slow], those which
846 don't are marked as [fast].
847 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
848 for further information
849
850 ***** ACL TYPES AVAILABLE *****
851
852 acl aclname src ip-address/mask ... # clients IP address [fast]
853 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
854 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
855 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
856
857 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
858 # The arp ACL requires the special configure option --enable-arp-acl.
859 # Furthermore, the ARP ACL code is not portable to all operating systems.
860 # It works on Linux, Solaris, Windows, FreeBSD, and some
861 # other *BSD variants.
862 # [fast]
863 #
864 # NOTE: Squid can only determine the MAC address for clients that are on
865 # the same subnet. If the client is on a different subnet,
866 # then Squid cannot find out its MAC address.
867
868 acl aclname srcdomain .foo.com ...
869 # reverse lookup, from client IP [slow]
870 acl aclname dstdomain [-n] .foo.com ...
871 # Destination server from URL [fast]
872 acl aclname srcdom_regex [-i] \.foo\.com ...
873 # regex matching client name [slow]
874 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
875 # regex matching server [fast]
876 #
877 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
878 # based URL is used and no match is found. The name "none" is used
879 # if the reverse lookup fails.
880
881 acl aclname src_as number ...
882 acl aclname dst_as number ...
883 # [fast]
884 # Except for access control, AS numbers can be used for
885 # routing of requests to specific caches. Here's an
886 # example for routing all requests for AS#1241 and only
887 # those to mycache.mydomain.net:
888 # acl asexample dst_as 1241
889 # cache_peer_access mycache.mydomain.net allow asexample
890 # cache_peer_access mycache_mydomain.net deny all
891
892 acl aclname peername myPeer ...
893 # [fast]
894 # match against a named cache_peer entry
895 # set unique name= on cache_peer lines for reliable use.
896
897 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
898 # [fast]
899 # day-abbrevs:
900 # S - Sunday
901 # M - Monday
902 # T - Tuesday
903 # W - Wednesday
904 # H - Thursday
905 # F - Friday
906 # A - Saturday
907 # h1:m1 must be less than h2:m2
908
909 acl aclname url_regex [-i] ^http:// ...
910 # regex matching on whole URL [fast]
911 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
912 # regex matching on URL login field
913 acl aclname urlpath_regex [-i] \.gif$ ...
914 # regex matching on URL path [fast]
915
916 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
917 # ranges are alloed
918 acl aclname localport 3128 ... # TCP port the client connected to [fast]
919 # NP: for interception mode this is usually '80'
920
921 acl aclname myportname 3128 ... # http(s)_port name [fast]
922
923 acl aclname proto HTTP FTP ... # request protocol [fast]
924
925 acl aclname method GET POST ... # HTTP request method [fast]
926
927 acl aclname http_status 200 301 500- 400-403 ...
928 # status code in reply [fast]
929
930 acl aclname browser [-i] regexp ...
931 # pattern match on User-Agent header (see also req_header below) [fast]
932
933 acl aclname referer_regex [-i] regexp ...
934 # pattern match on Referer header [fast]
935 # Referer is highly unreliable, so use with care
936
937 acl aclname ident username ...
938 acl aclname ident_regex [-i] pattern ...
939 # string match on ident output [slow]
940 # use REQUIRED to accept any non-null ident.
941
942 acl aclname proxy_auth [-i] username ...
943 acl aclname proxy_auth_regex [-i] pattern ...
944 # perform http authentication challenge to the client and match against
945 # supplied credentials [slow]
946 #
947 # takes a list of allowed usernames.
948 # use REQUIRED to accept any valid username.
949 #
950 # Will use proxy authentication in forward-proxy scenarios, and plain
951 # http authenticaiton in reverse-proxy scenarios
952 #
953 # NOTE: when a Proxy-Authentication header is sent but it is not
954 # needed during ACL checking the username is NOT logged
955 # in access.log.
956 #
957 # NOTE: proxy_auth requires a EXTERNAL authentication program
958 # to check username/password combinations (see
959 # auth_param directive).
960 #
961 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
962 # as the browser needs to be configured for using a proxy in order
963 # to respond to proxy authentication.
964
965 acl aclname snmp_community string ...
966 # A community string to limit access to your SNMP Agent [fast]
967 # Example:
968 #
969 # acl snmppublic snmp_community public
970
971 acl aclname maxconn number
972 # This will be matched when the client's IP address has
973 # more than <number> TCP connections established. [fast]
974 # NOTE: This only measures direct TCP links so X-Forwarded-For
975 # indirect clients are not counted.
976
977 acl aclname max_user_ip [-s] number
978 # This will be matched when the user attempts to log in from more
979 # than <number> different ip addresses. The authenticate_ip_ttl
980 # parameter controls the timeout on the ip entries. [fast]
981 # If -s is specified the limit is strict, denying browsing
982 # from any further IP addresses until the ttl has expired. Without
983 # -s Squid will just annoy the user by "randomly" denying requests.
984 # (the counter is reset each time the limit is reached and a
985 # request is denied)
986 # NOTE: in acceleration mode or where there is mesh of child proxies,
987 # clients may appear to come from multiple addresses if they are
988 # going through proxy farms, so a limit of 1 may cause user problems.
989
990 acl aclname random probability
991 # Pseudo-randomly match requests. Based on the probability given.
992 # Probability may be written as a decimal (0.333), fraction (1/3)
993 # or ratio of matches:non-matches (3:5).
994
995 acl aclname req_mime_type [-i] mime-type ...
996 # regex match against the mime type of the request generated
997 # by the client. Can be used to detect file upload or some
998 # types HTTP tunneling requests [fast]
999 # NOTE: This does NOT match the reply. You cannot use this
1000 # to match the returned file type.
1001
1002 acl aclname req_header header-name [-i] any\.regex\.here
1003 # regex match against any of the known request headers. May be
1004 # thought of as a superset of "browser", "referer" and "mime-type"
1005 # ACL [fast]
1006
1007 acl aclname rep_mime_type [-i] mime-type ...
1008 # regex match against the mime type of the reply received by
1009 # squid. Can be used to detect file download or some
1010 # types HTTP tunneling requests. [fast]
1011 # NOTE: This has no effect in http_access rules. It only has
1012 # effect in rules that affect the reply data stream such as
1013 # http_reply_access.
1014
1015 acl aclname rep_header header-name [-i] any\.regex\.here
1016 # regex match against any of the known reply headers. May be
1017 # thought of as a superset of "browser", "referer" and "mime-type"
1018 # ACLs [fast]
1019
1020 acl aclname external class_name [arguments...]
1021 # external ACL lookup via a helper class defined by the
1022 # external_acl_type directive [slow]
1023
1024 acl aclname user_cert attribute values...
1025 # match against attributes in a user SSL certificate
1026 # attribute is one of DN/C/O/CN/L/ST [fast]
1027
1028 acl aclname ca_cert attribute values...
1029 # match against attributes a users issuing CA SSL certificate
1030 # attribute is one of DN/C/O/CN/L/ST [fast]
1031
1032 acl aclname ext_user username ...
1033 acl aclname ext_user_regex [-i] pattern ...
1034 # string match on username returned by external acl helper [slow]
1035 # use REQUIRED to accept any non-null user name.
1036
1037 acl aclname tag tagvalue ...
1038 # string match on tag returned by external acl helper [slow]
1039
1040 acl aclname hier_code codename ...
1041 # string match against squid hierarchy code(s); [fast]
1042 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1043 #
1044 # NOTE: This has no effect in http_access rules. It only has
1045 # effect in rules that affect the reply data stream such as
1046 # http_reply_access.
1047
1048IF USE_SSL
1049 acl aclname ssl_error errorname
1050 # match against SSL certificate validation error [fast]
1051 #
1052 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1053 # template file.
1054 #
1055 # The following can be used as shortcuts for certificate properties:
1056 # [ssl::]certHasExpired: the "not after" field is in the past
1057 # [ssl::]certNotYetValid: the "not before" field is in the future
1058 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1059 # [ssl::]certSelfSigned: The certificate is self signed.
1060 # [ssl::]certDomainMismatch: The certificate CN domain does not
1061 # match the name the name of the host we are connecting to.
1062 #
1063 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1064 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1065 # predefined ACLs, just like the 'all' ACL.
1066 #
1067 # NOTE: The ssl_error ACL is only supported with sslproxy_cert_error,
1068 # sslproxy_cert_sign, and sslproxy_cert_adapt options.
1069
1070 acl aclname server_cert_fingerprint [-sha1] fingerprint
1071 # match against server SSL certificate fingerprint [fast]
1072 #
1073 # The fingerprint is the digest of the DER encoded version
1074 # of the whole certificate. The user should use the form: XX:XX:...
1075 # Optional argument specifies the digest algorithm to use.
1076 # The SHA1 digest algorithm is the default and is currently
1077 # the only algorithm supported (-sha1).
1078ENDIF
1079
1080 Examples:
1081 acl macaddress arp 09:00:2b:23:45:67
1082 acl myexample dst_as 1241
1083 acl password proxy_auth REQUIRED
1084 acl fileupload req_mime_type -i ^multipart/form-data$
1085 acl javascript rep_mime_type -i ^application/x-javascript$
1086
1087NOCOMMENT_START
1088#
1089# Recommended minimum configuration:
1090#
1091
1092# Example rule allowing access from your local networks.
1093# Adapt to list your (internal) IP networks from where browsing
1094# should be allowed
1095acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
1096acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
1097acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
1098acl localnet src fc00::/7 # RFC 4193 local private network range
1099acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1100
1101acl SSL_ports port 443
1102acl Safe_ports port 80 # http
1103acl Safe_ports port 21 # ftp
1104acl Safe_ports port 443 # https
1105acl Safe_ports port 70 # gopher
1106acl Safe_ports port 210 # wais
1107acl Safe_ports port 1025-65535 # unregistered ports
1108acl Safe_ports port 280 # http-mgmt
1109acl Safe_ports port 488 # gss-http
1110acl Safe_ports port 591 # filemaker
1111acl Safe_ports port 777 # multiling http
1112acl CONNECT method CONNECT
1113NOCOMMENT_END
1114DOC_END
1115
1116NAME: follow_x_forwarded_for
1117TYPE: acl_access
1118IFDEF: FOLLOW_X_FORWARDED_FOR
1119LOC: Config.accessList.followXFF
1120DEFAULT_IF_NONE: deny all
1121DEFAULT_DOC: X-Forwarded-For header will be ignored.
1122DOC_START
1123 Allowing or Denying the X-Forwarded-For header to be followed to
1124 find the original source of a request.
1125
1126 Requests may pass through a chain of several other proxies
1127 before reaching us. The X-Forwarded-For header will contain a
1128 comma-separated list of the IP addresses in the chain, with the
1129 rightmost address being the most recent.
1130
1131 If a request reaches us from a source that is allowed by this
1132 configuration item, then we consult the X-Forwarded-For header
1133 to see where that host received the request from. If the
1134 X-Forwarded-For header contains multiple addresses, we continue
1135 backtracking until we reach an address for which we are not allowed
1136 to follow the X-Forwarded-For header, or until we reach the first
1137 address in the list. For the purpose of ACL used in the
1138 follow_x_forwarded_for directive the src ACL type always matches
1139 the address we are testing and srcdomain matches its rDNS.
1140
1141 The end result of this process is an IP address that we will
1142 refer to as the indirect client address. This address may
1143 be treated as the client address for access control, ICAP, delay
1144 pools and logging, depending on the acl_uses_indirect_client,
1145 icap_uses_indirect_client, delay_pool_uses_indirect_client,
1146 log_uses_indirect_client and tproxy_uses_indirect_client options.
1147
1148 This clause only supports fast acl types.
1149 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1150
1151 SECURITY CONSIDERATIONS:
1152
1153 Any host for which we follow the X-Forwarded-For header
1154 can place incorrect information in the header, and Squid
1155 will use the incorrect information as if it were the
1156 source address of the request. This may enable remote
1157 hosts to bypass any access control restrictions that are
1158 based on the client's source addresses.
1159
1160 For example:
1161
1162 acl localhost src 127.0.0.1
1163 acl my_other_proxy srcdomain .proxy.example.com
1164 follow_x_forwarded_for allow localhost
1165 follow_x_forwarded_for allow my_other_proxy
1166DOC_END
1167
1168NAME: acl_uses_indirect_client
1169COMMENT: on|off
1170TYPE: onoff
1171IFDEF: FOLLOW_X_FORWARDED_FOR
1172DEFAULT: on
1173LOC: Config.onoff.acl_uses_indirect_client
1174DOC_START
1175 Controls whether the indirect client address
1176 (see follow_x_forwarded_for) is used instead of the
1177 direct client address in acl matching.
1178
1179 NOTE: maxconn ACL considers direct TCP links and indirect
1180 clients will always have zero. So no match.
1181DOC_END
1182
1183NAME: delay_pool_uses_indirect_client
1184COMMENT: on|off
1185TYPE: onoff
1186IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
1187DEFAULT: on
1188LOC: Config.onoff.delay_pool_uses_indirect_client
1189DOC_START
1190 Controls whether the indirect client address
1191 (see follow_x_forwarded_for) is used instead of the
1192 direct client address in delay pools.
1193DOC_END
1194
1195NAME: log_uses_indirect_client
1196COMMENT: on|off
1197TYPE: onoff
1198IFDEF: FOLLOW_X_FORWARDED_FOR
1199DEFAULT: on
1200LOC: Config.onoff.log_uses_indirect_client
1201DOC_START
1202 Controls whether the indirect client address
1203 (see follow_x_forwarded_for) is used instead of the
1204 direct client address in the access log.
1205DOC_END
1206
1207NAME: tproxy_uses_indirect_client
1208COMMENT: on|off
1209TYPE: onoff
1210IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
1211DEFAULT: off
1212LOC: Config.onoff.tproxy_uses_indirect_client
1213DOC_START
1214 Controls whether the indirect client address
1215 (see follow_x_forwarded_for) is used instead of the
1216 direct client address when spoofing the outgoing client.
1217
1218 This has no effect on requests arriving in non-tproxy
1219 mode ports.
1220
1221 SECURITY WARNING: Usage of this option is dangerous
1222 and should not be used trivially. Correct configuration
1223 of follow_x_forewarded_for with a limited set of trusted
1224 sources is required to prevent abuse of your proxy.
1225DOC_END
1226
1227NAME: http_access
1228TYPE: acl_access
1229LOC: Config.accessList.http
1230DEFAULT_IF_NONE: deny all
1231DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1232DOC_START
1233 Allowing or Denying access based on defined access lists
1234
1235 Access to the HTTP port:
1236 http_access allow|deny [!]aclname ...
1237
1238 NOTE on default values:
1239
1240 If there are no "access" lines present, the default is to deny
1241 the request.
1242
1243 If none of the "access" lines cause a match, the default is the
1244 opposite of the last line in the list. If the last line was
1245 deny, the default is allow. Conversely, if the last line
1246 is allow, the default will be deny. For these reasons, it is a
1247 good idea to have an "deny all" entry at the end of your access
1248 lists to avoid potential confusion.
1249
1250 This clause supports both fast and slow acl types.
1251 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1252
1253NOCOMMENT_START
1254
1255#
1256# Recommended minimum Access Permission configuration:
1257#
1258# Deny requests to certain unsafe ports
1259http_access deny !Safe_ports
1260
1261# Deny CONNECT to other than secure SSL ports
1262http_access deny CONNECT !SSL_ports
1263
1264# Only allow cachemgr access from localhost
1265http_access allow localhost manager
1266http_access deny manager
1267
1268# We strongly recommend the following be uncommented to protect innocent
1269# web applications running on the proxy server who think the only
1270# one who can access services on "localhost" is a local user
1271#http_access deny to_localhost
1272
1273#
1274# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1275#
1276
1277# Example rule allowing access from your local networks.
1278# Adapt localnet in the ACL section to list your (internal) IP networks
1279# from where browsing should be allowed
1280http_access allow localnet
1281http_access allow localhost
1282
1283# And finally deny all other access to this proxy
1284http_access deny all
1285NOCOMMENT_END
1286DOC_END
1287
1288NAME: adapted_http_access http_access2
1289TYPE: acl_access
1290LOC: Config.accessList.adapted_http
1291DEFAULT: none
1292DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1293DOC_START
1294 Allowing or Denying access based on defined access lists
1295
1296 Essentially identical to http_access, but runs after redirectors
1297 and ICAP/eCAP adaptation. Allowing access control based on their
1298 output.
1299
1300 If not set then only http_access is used.
1301DOC_END
1302
1303NAME: http_reply_access
1304TYPE: acl_access
1305LOC: Config.accessList.reply
1306DEFAULT: none
1307DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1308DOC_START
1309 Allow replies to client requests. This is complementary to http_access.
1310
1311 http_reply_access allow|deny [!] aclname ...
1312
1313 NOTE: if there are no access lines present, the default is to allow
1314 all replies.
1315
1316 If none of the access lines cause a match the opposite of the
1317 last line will apply. Thus it is good practice to end the rules
1318 with an "allow all" or "deny all" entry.
1319
1320 This clause supports both fast and slow acl types.
1321 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1322DOC_END
1323
1324NAME: icp_access
1325TYPE: acl_access
1326LOC: Config.accessList.icp
1327DEFAULT: none
1328DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1329DOC_START
1330 Allowing or Denying access to the ICP port based on defined
1331 access lists
1332
1333 icp_access allow|deny [!]aclname ...
1334
1335 NOTE: The default if no icp_access lines are present is to
1336 deny all traffic. This default may cause problems with peers
1337 using ICP.
1338
1339 This clause only supports fast acl types.
1340 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1341
1342# Allow ICP queries from local networks only
1343#icp_access allow localnet
1344#icp_access deny all
1345DOC_END
1346
1347NAME: htcp_access
1348IFDEF: USE_HTCP
1349TYPE: acl_access
1350LOC: Config.accessList.htcp
1351DEFAULT: none
1352DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1353DOC_START
1354 Allowing or Denying access to the HTCP port based on defined
1355 access lists
1356
1357 htcp_access allow|deny [!]aclname ...
1358
1359 See also htcp_clr_access for details on access control for
1360 cache purge (CLR) HTCP messages.
1361
1362 NOTE: The default if no htcp_access lines are present is to
1363 deny all traffic. This default may cause problems with peers
1364 using the htcp option.
1365
1366 This clause only supports fast acl types.
1367 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1368
1369# Allow HTCP queries from local networks only
1370#htcp_access allow localnet
1371#htcp_access deny all
1372DOC_END
1373
1374NAME: htcp_clr_access
1375IFDEF: USE_HTCP
1376TYPE: acl_access
1377LOC: Config.accessList.htcp_clr
1378DEFAULT: none
1379DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1380DOC_START
1381 Allowing or Denying access to purge content using HTCP based
1382 on defined access lists.
1383 See htcp_access for details on general HTCP access control.
1384
1385 htcp_clr_access allow|deny [!]aclname ...
1386
1387 This clause only supports fast acl types.
1388 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1389
1390# Allow HTCP CLR requests from trusted peers
1391acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1392htcp_clr_access allow htcp_clr_peer
1393htcp_clr_access deny all
1394DOC_END
1395
1396NAME: miss_access
1397TYPE: acl_access
1398LOC: Config.accessList.miss
1399DEFAULT: none
1400DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1401DOC_START
1402 Determins whether network access is permitted when satisfying a request.
1403
1404 For example;
1405 to force your neighbors to use you as a sibling instead of
1406 a parent.
1407
1408 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1409 miss_access deny !localclients
1410 miss_access allow all
1411
1412 This means only your local clients are allowed to fetch relayed/MISS
1413 replies from the network and all other clients can only fetch cached
1414 objects (HITs).
1415
1416 The default for this setting allows all clients who passed the
1417 http_access rules to relay via this proxy.
1418
1419 This clause only supports fast acl types.
1420 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1421DOC_END
1422
1423NAME: ident_lookup_access
1424TYPE: acl_access
1425IFDEF: USE_IDENT
1426DEFAULT: none
1427DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
1428LOC: Ident::TheConfig.identLookup
1429DOC_START
1430 A list of ACL elements which, if matched, cause an ident
1431 (RFC 931) lookup to be performed for this request. For
1432 example, you might choose to always perform ident lookups
1433 for your main multi-user Unix boxes, but not for your Macs
1434 and PCs. By default, ident lookups are not performed for
1435 any requests.
1436
1437 To enable ident lookups for specific client addresses, you
1438 can follow this example:
1439
1440 acl ident_aware_hosts src 198.168.1.0/24
1441 ident_lookup_access allow ident_aware_hosts
1442 ident_lookup_access deny all
1443
1444 Only src type ACL checks are fully supported. A srcdomain
1445 ACL might work at times, but it will not always provide
1446 the correct result.
1447
1448 This clause only supports fast acl types.
1449 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1450DOC_END
1451
1452NAME: reply_body_max_size
1453COMMENT: size [acl acl...]
1454TYPE: acl_b_size_t
1455DEFAULT: none
1456DEFAULT_DOC: No limit is applied.
1457LOC: Config.ReplyBodySize
1458DOC_START
1459 This option specifies the maximum size of a reply body. It can be
1460 used to prevent users from downloading very large files, such as
1461 MP3's and movies. When the reply headers are received, the
1462 reply_body_max_size lines are processed, and the first line where
1463 all (if any) listed ACLs are true is used as the maximum body size
1464 for this reply.
1465
1466 This size is checked twice. First when we get the reply headers,
1467 we check the content-length value. If the content length value exists
1468 and is larger than the allowed size, the request is denied and the
1469 user receives an error message that says "the request or reply
1470 is too large." If there is no content-length, and the reply
1471 size exceeds this limit, the client's connection is just closed
1472 and they will receive a partial reply.
1473
1474 WARNING: downstream caches probably can not detect a partial reply
1475 if there is no content-length header, so they will cache
1476 partial responses and give them out as hits. You should NOT
1477 use this option if you have downstream caches.
1478
1479 WARNING: A maximum size smaller than the size of squid's error messages
1480 will cause an infinite loop and crash squid. Ensure that the smallest
1481 non-zero value you use is greater that the maximum header size plus
1482 the size of your largest error page.
1483
1484 If you set this parameter none (the default), there will be
1485 no limit imposed.
1486
1487 Configuration Format is:
1488 reply_body_max_size SIZE UNITS [acl ...]
1489 ie.
1490 reply_body_max_size 10 MB
1491
1492DOC_END
1493
1494COMMENT_START
1495 NETWORK OPTIONS
1496 -----------------------------------------------------------------------------
1497COMMENT_END
1498
1499NAME: http_port ascii_port
1500TYPE: PortCfg
1501DEFAULT: none
1502LOC: Config.Sockaddr.http
1503DOC_START
1504 Usage: port [mode] [options]
1505 hostname:port [mode] [options]
1506 1.2.3.4:port [mode] [options]
1507
1508 The socket addresses where Squid will listen for HTTP client
1509 requests. You may specify multiple socket addresses.
1510 There are three forms: port alone, hostname with port, and
1511 IP address with port. If you specify a hostname or IP
1512 address, Squid binds the socket to that specific
1513 address. Most likely, you do not need to bind to a specific
1514 address, so you can use the port number alone.
1515
1516 If you are running Squid in accelerator mode, you
1517 probably want to listen on port 80 also, or instead.
1518
1519 The -a command line option may be used to specify additional
1520 port(s) where Squid listens for proxy request. Such ports will
1521 be plain proxy ports with no options.
1522
1523 You may specify multiple socket addresses on multiple lines.
1524
1525 Modes:
1526
1527 intercept Support for IP-Layer interception of
1528 outgoing requests without browser settings.
1529 NP: disables authentication and IPv6 on the port.
1530
1531 tproxy Support Linux TPROXY for spoofing outgoing
1532 connections using the client IP address.
1533 NP: disables authentication and maybe IPv6 on the port.
1534
1535 accel Accelerator / reverse proxy mode
1536
1537 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1538 establish secure connection with the client and with
1539 the server, decrypt HTTPS messages as they pass through
1540 Squid, and treat them as unencrypted HTTP messages,
1541 becoming the man-in-the-middle.
1542
1543 The ssl_bump option is required to fully enable
1544 bumping of CONNECT requests.
1545
1546 Omitting the mode flag causes default forward proxy mode to be used.
1547
1548
1549 Accelerator Mode Options:
1550
1551 defaultsite=domainname
1552 What to use for the Host: header if it is not present
1553 in a request. Determines what site (not origin server)
1554 accelerators should consider the default.
1555
1556 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1557
1558 protocol= Protocol to reconstruct accelerated requests with.
1559 Defaults to http for http_port and https for
1560 https_port
1561
1562 vport Virtual host port support. Using the http_port number
1563 instead of the port passed on Host: headers.
1564
1565 vport=NN Virtual host port support. Using the specified port
1566 number instead of the port passed on Host: headers.
1567
1568 act-as-origin
1569 Act as if this Squid is the origin server.
1570 This currently means generate new Date: and Expires:
1571 headers on HIT instead of adding Age:.
1572
1573 ignore-cc Ignore request Cache-Control headers.
1574
1575 WARNING: This option violates HTTP specifications if
1576 used in non-accelerator setups.
1577
1578 allow-direct Allow direct forwarding in accelerator mode. Normally
1579 accelerated requests are denied direct forwarding as if
1580 never_direct was used.
1581
1582 WARNING: this option opens accelerator mode to security
1583 vulnerabilities usually only affecting in interception
1584 mode. Make sure to protect forwarding with suitable
1585 http_access rules when using this.
1586
1587
1588 SSL Bump Mode Options:
1589 In addition to these options ssl-bump requires TLS/SSL options.
1590
1591 generate-host-certificates[=<on|off>]
1592 Dynamically create SSL server certificates for the
1593 destination hosts of bumped CONNECT requests.When
1594 enabled, the cert and key options are used to sign
1595 generated certificates. Otherwise generated
1596 certificate will be selfsigned.
1597 If there is a CA certificate lifetime of the generated
1598 certificate equals lifetime of the CA certificate. If
1599 generated certificate is selfsigned lifetime is three
1600 years.
1601 This option is enabled by default when ssl-bump is used.
1602 See the ssl-bump option above for more information.
1603
1604 dynamic_cert_mem_cache_size=SIZE
1605 Approximate total RAM size spent on cached generated
1606 certificates. If set to zero, caching is disabled. The
1607 default value is 4MB.
1608
1609 TLS / SSL Options:
1610
1611 cert= Path to SSL certificate (PEM format).
1612
1613 key= Path to SSL private key file (PEM format)
1614 if not specified, the certificate file is
1615 assumed to be a combined certificate and
1616 key file.
1617
1618 version= The version of SSL/TLS supported
1619 1 automatic (default)
1620 2 SSLv2 only
1621 3 SSLv3 only
1622 4 TLSv1.0 only
1623 5 TLSv1.1 only
1624 6 TLSv1.2 only
1625
1626 cipher= Colon separated list of supported ciphers.
1627 NOTE: some ciphers such as EDH ciphers depend on
1628 additional settings. If those settings are
1629 omitted the ciphers may be silently ignored
1630 by the OpenSSL library.
1631
1632 options= Various SSL implementation options. The most important
1633 being:
1634 NO_SSLv2 Disallow the use of SSLv2
1635 NO_SSLv3 Disallow the use of SSLv3
1636 NO_TLSv1 Disallow the use of TLSv1.0
1637 NO_TLSv1_1 Disallow the use of TLSv1.1
1638 NO_TLSv1_2 Disallow the use of TLSv1.2
1639 SINGLE_DH_USE Always create a new key when using
1640 temporary/ephemeral DH key exchanges
1641 ALL Enable various bug workarounds
1642 suggested as "harmless" by OpenSSL
1643 Be warned that this reduces SSL/TLS
1644 strength to some attacks.
1645 See OpenSSL SSL_CTX_set_options documentation for a
1646 complete list of options.
1647
1648 clientca= File containing the list of CAs to use when
1649 requesting a client certificate.
1650
1651 cafile= File containing additional CA certificates to
1652 use when verifying client certificates. If unset
1653 clientca will be used.
1654
1655 capath= Directory containing additional CA certificates
1656 and CRL lists to use when verifying client certificates.
1657
1658 crlfile= File of additional CRL lists to use when verifying
1659 the client certificate, in addition to CRLs stored in
1660 the capath. Implies VERIFY_CRL flag below.
1661
1662 dhparams= File containing DH parameters for temporary/ephemeral
1663 DH key exchanges. See OpenSSL documentation for details
1664 on how to create this file.
1665 WARNING: EDH ciphers will be silently disabled if this
1666 option is not set.
1667
1668 sslflags= Various flags modifying the use of SSL:
1669 DELAYED_AUTH
1670 Don't request client certificates
1671 immediately, but wait until acl processing
1672 requires a certificate (not yet implemented).
1673 NO_DEFAULT_CA
1674 Don't use the default CA lists built in
1675 to OpenSSL.
1676 NO_SESSION_REUSE
1677 Don't allow for session reuse. Each connection
1678 will result in a new SSL session.
1679 VERIFY_CRL
1680 Verify CRL lists when accepting client
1681 certificates.
1682 VERIFY_CRL_ALL
1683 Verify CRL lists for all certificates in the
1684 client certificate chain.
1685
1686 sslcontext= SSL session ID context identifier.
1687
1688 Other Options:
1689
1690 connection-auth[=on|off]
1691 use connection-auth=off to tell Squid to prevent
1692 forwarding Microsoft connection oriented authentication
1693 (NTLM, Negotiate and Kerberos)
1694
1695 disable-pmtu-discovery=
1696 Control Path-MTU discovery usage:
1697 off lets OS decide on what to do (default).
1698 transparent disable PMTU discovery when transparent
1699 support is enabled.
1700 always disable always PMTU discovery.
1701
1702 In many setups of transparently intercepting proxies
1703 Path-MTU discovery can not work on traffic towards the
1704 clients. This is the case when the intercepting device
1705 does not fully track connections and fails to forward
1706 ICMP must fragment messages to the cache server. If you
1707 have such setup and experience that certain clients
1708 sporadically hang or never complete requests set
1709 disable-pmtu-discovery option to 'transparent'.
1710
1711 name= Specifies a internal name for the port. Defaults to
1712 the port specification (port or addr:port)
1713
1714 tcpkeepalive[=idle,interval,timeout]
1715 Enable TCP keepalive probes of idle connections.
1716 In seconds; idle is the initial time before TCP starts
1717 probing the connection, interval how often to probe, and
1718 timeout the time before giving up.
1719
1720 If you run Squid on a dual-homed machine with an internal
1721 and an external interface we recommend you to specify the
1722 internal address:port in http_port. This way Squid will only be
1723 visible on the internal address.
1724
1725NOCOMMENT_START
1726
1727# Squid normally listens to port 3128
1728http_port @DEFAULT_HTTP_PORT@
1729NOCOMMENT_END
1730DOC_END
1731
1732NAME: https_port
1733IFDEF: USE_SSL
1734TYPE: PortCfg
1735DEFAULT: none
1736LOC: Config.Sockaddr.https
1737DOC_START
1738 Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1739
1740 The socket address where Squid will listen for client requests made
1741 over TLS or SSL connections. Commonly referred to as HTTPS.
1742
1743 This is most useful for situations where you are running squid in
1744 accelerator mode and you want to do the SSL work at the accelerator level.
1745
1746 You may specify multiple socket addresses on multiple lines,
1747 each with their own SSL certificate and/or options.
1748
1749 Modes:
1750
1751 accel Accelerator / reverse proxy mode
1752
1753 intercept Support for IP-Layer interception of
1754 outgoing requests without browser settings.
1755 NP: disables authentication and IPv6 on the port.
1756
1757 tproxy Support Linux TPROXY for spoofing outgoing
1758 connections using the client IP address.
1759 NP: disables authentication and maybe IPv6 on the port.
1760
1761 ssl-bump For each intercepted connection allowed by ssl_bump
1762 ACLs, establish a secure connection with the client and with
1763 the server, decrypt HTTPS messages as they pass through
1764 Squid, and treat them as unencrypted HTTP messages,
1765 becoming the man-in-the-middle.
1766
1767 An "ssl_bump server-first" match is required to
1768 fully enable bumping of intercepted SSL connections.
1769
1770 Requires tproxy or intercept.
1771
1772 Omitting the mode flag causes default forward proxy mode to be used.
1773
1774
1775 See http_port for a list of generic options
1776
1777
1778 SSL Options:
1779
1780 cert= Path to SSL certificate (PEM format).
1781
1782 key= Path to SSL private key file (PEM format)
1783 if not specified, the certificate file is
1784 assumed to be a combined certificate and
1785 key file.
1786
1787 version= The version of SSL/TLS supported
1788 1 automatic (default)
1789 2 SSLv2 only
1790 3 SSLv3 only
1791 4 TLSv1 only
1792
1793 cipher= Colon separated list of supported ciphers.
1794
1795 options= Various SSL engine options. The most important
1796 being:
1797 NO_SSLv2 Disallow the use of SSLv2
1798 NO_SSLv3 Disallow the use of SSLv3
1799 NO_TLSv1 Disallow the use of TLSv1
1800 SINGLE_DH_USE Always create a new key when using
1801 temporary/ephemeral DH key exchanges
1802 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1803 documentation for a complete list of options.
1804
1805 clientca= File containing the list of CAs to use when
1806 requesting a client certificate.
1807
1808 cafile= File containing additional CA certificates to
1809 use when verifying client certificates. If unset
1810 clientca will be used.
1811
1812 capath= Directory containing additional CA certificates
1813 and CRL lists to use when verifying client certificates.
1814
1815 crlfile= File of additional CRL lists to use when verifying
1816 the client certificate, in addition to CRLs stored in
1817 the capath. Implies VERIFY_CRL flag below.
1818
1819 dhparams= File containing DH parameters for temporary/ephemeral
1820 DH key exchanges.
1821
1822 sslflags= Various flags modifying the use of SSL:
1823 DELAYED_AUTH
1824 Don't request client certificates
1825 immediately, but wait until acl processing
1826 requires a certificate (not yet implemented).
1827 NO_DEFAULT_CA
1828 Don't use the default CA lists built in
1829 to OpenSSL.
1830 NO_SESSION_REUSE
1831 Don't allow for session reuse. Each connection
1832 will result in a new SSL session.
1833 VERIFY_CRL
1834 Verify CRL lists when accepting client
1835 certificates.
1836 VERIFY_CRL_ALL
1837 Verify CRL lists for all certificates in the
1838 client certificate chain.
1839
1840 sslcontext= SSL session ID context identifier.
1841
1842 generate-host-certificates[=<on|off>]
1843 Dynamically create SSL server certificates for the
1844 destination hosts of bumped SSL requests.When
1845 enabled, the cert and key options are used to sign
1846 generated certificates. Otherwise generated
1847 certificate will be selfsigned.
1848 If there is CA certificate life time of generated
1849 certificate equals lifetime of CA certificate. If
1850 generated certificate is selfsigned lifetime is three
1851 years.
1852 This option is enabled by default when SslBump is used.
1853 See the sslBump option above for more information.
1854
1855 dynamic_cert_mem_cache_size=SIZE
1856 Approximate total RAM size spent on cached generated
1857 certificates. If set to zero, caching is disabled. The
1858 default value is 4MB.
1859
1860 See http_port for a list of available options.
1861DOC_END
1862
1863NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
1864TYPE: acl_tos
1865DEFAULT: none
1866LOC: Ip::Qos::TheConfig.tosToServer
1867DOC_START
1868 Allows you to select a TOS/Diffserv value for packets outgoing
1869 on the server side, based on an ACL.
1870
1871 tcp_outgoing_tos ds-field [!]aclname ...
1872
1873 Example where normal_service_net uses the TOS value 0x00
1874 and good_service_net uses 0x20
1875
1876 acl normal_service_net src 10.0.0.0/24
1877 acl good_service_net src 10.0.1.0/24
1878 tcp_outgoing_tos 0x00 normal_service_net
1879 tcp_outgoing_tos 0x20 good_service_net
1880
1881 TOS/DSCP values really only have local significance - so you should
1882 know what you're specifying. For more information, see RFC2474,
1883 RFC2475, and RFC3260.
1884
1885 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1886 "default" to use whatever default your host has. Note that in
1887 practice often only multiples of 4 is usable as the two rightmost bits
1888 have been redefined for use by ECN (RFC 3168 section 23.1).
1889
1890 Processing proceeds in the order specified, and stops at first fully
1891 matching line.
1892DOC_END
1893
1894NAME: clientside_tos
1895TYPE: acl_tos
1896DEFAULT: none
1897LOC: Ip::Qos::TheConfig.tosToClient
1898DOC_START
1899 Allows you to select a TOS/Diffserv value for packets being transmitted
1900 on the client-side, based on an ACL.
1901
1902 clientside_tos ds-field [!]aclname ...
1903
1904 Example where normal_service_net uses the TOS value 0x00
1905 and good_service_net uses 0x20
1906
1907 acl normal_service_net src 10.0.0.0/24
1908 acl good_service_net src 10.0.1.0/24
1909 clientside_tos 0x00 normal_service_net
1910 clientside_tos 0x20 good_service_net
1911
1912 Note: This feature is incompatible with qos_flows. Any TOS values set here
1913 will be overwritten by TOS values in qos_flows.
1914DOC_END
1915
1916NAME: tcp_outgoing_mark
1917TYPE: acl_nfmark
1918IFDEF: SO_MARK&&USE_LIBCAP
1919DEFAULT: none
1920LOC: Ip::Qos::TheConfig.nfmarkToServer
1921DOC_START
1922 Allows you to apply a Netfilter mark value to outgoing packets
1923 on the server side, based on an ACL.
1924
1925 tcp_outgoing_mark mark-value [!]aclname ...
1926
1927 Example where normal_service_net uses the mark value 0x00
1928 and good_service_net uses 0x20
1929
1930 acl normal_service_net src 10.0.0.0/24
1931 acl good_service_net src 10.0.1.0/24
1932 tcp_outgoing_mark 0x00 normal_service_net
1933 tcp_outgoing_mark 0x20 good_service_net
1934DOC_END
1935
1936NAME: clientside_mark
1937TYPE: acl_nfmark
1938IFDEF: SO_MARK&&USE_LIBCAP
1939DEFAULT: none
1940LOC: Ip::Qos::TheConfig.nfmarkToClient
1941DOC_START
1942 Allows you to apply a Netfilter mark value to packets being transmitted
1943 on the client-side, based on an ACL.
1944
1945 clientside_mark mark-value [!]aclname ...
1946
1947 Example where normal_service_net uses the mark value 0x00
1948 and good_service_net uses 0x20
1949
1950 acl normal_service_net src 10.0.0.0/24
1951 acl good_service_net src 10.0.1.0/24
1952 clientside_mark 0x00 normal_service_net
1953 clientside_mark 0x20 good_service_net
1954
1955 Note: This feature is incompatible with qos_flows. Any mark values set here
1956 will be overwritten by mark values in qos_flows.
1957DOC_END
1958
1959NAME: qos_flows
1960TYPE: QosConfig
1961IFDEF: USE_QOS_TOS
1962DEFAULT: none
1963LOC: Ip::Qos::TheConfig
1964DOC_START
1965 Allows you to select a TOS/DSCP value to mark outgoing
1966 connections with, based on where the reply was sourced. For
1967 platforms using netfilter, allows you to set a netfilter mark
1968 value instead of, or in addition to, a TOS value.
1969
1970 TOS values really only have local significance - so you should
1971 know what you're specifying. For more information, see RFC2474,
1972 RFC2475, and RFC3260.
1973
1974 The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
1975 in practice often only multiples of 4 is usable as the two rightmost bits
1976 have been redefined for use by ECN (RFC 3168 section 23.1).
1977
1978 Mark values can be any unsigned 32-bit integer value.
1979
1980 This setting is configured by setting the following values:
1981
1982 tos|mark Whether to set TOS or netfilter mark values
1983
1984 local-hit=0xFF Value to mark local cache hits.
1985
1986 sibling-hit=0xFF Value to mark hits from sibling peers.
1987
1988 parent-hit=0xFF Value to mark hits from parent peers.
1989
1990 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
1991 over the preserve-miss feature (see below), unless
1992 mask is specified, in which case only the bits
1993 specified in the mask are written.
1994
1995 The TOS variant of the following features are only possible on Linux
1996 and require your kernel to be patched with the TOS preserving ZPH
1997 patch, available from http://zph.bratcheda.org
1998 No patch is needed to preserve the netfilter mark, which will work
1999 with all variants of netfilter.
2000
2001 disable-preserve-miss
2002 This option disables the preservation of the TOS or netfilter
2003 mark. By default, the existing TOS or netfilter mark value of
2004 the response coming from the remote server will be retained
2005 and masked with miss-mark.
2006 NOTE: in the case of a netfilter mark, the mark must be set on
2007 the connection (using the CONNMARK target) not on the packet
2008 (MARK target).
2009
2010 miss-mask=0xFF
2011 Allows you to mask certain bits in the TOS or mark value
2012 received from the remote server, before copying the value to
2013 the TOS sent towards clients.
2014 Default for tos: 0xFF (TOS from server is not changed).
2015 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2016
2017 All of these features require the --enable-zph-qos compilation flag
2018 (enabled by default). Netfilter marking also requires the
2019 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2020 libcap 2.09+ (--with-libcap).
2021
2022DOC_END
2023
2024NAME: tcp_outgoing_address
2025TYPE: acl_address
2026DEFAULT: none
2027DEFAULT_DOC: Address selection is performed by the operating system.
2028LOC: Config.accessList.outgoing_address
2029DOC_START
2030 Allows you to map requests to different outgoing IP addresses
2031 based on the username or source address of the user making
2032 the request.
2033
2034 tcp_outgoing_address ipaddr [[!]aclname] ...
2035
2036 For example;
2037 Forwarding clients with dedicated IPs for certain subnets.
2038
2039 acl normal_service_net src 10.0.0.0/24
2040 acl good_service_net src 10.0.2.0/24
2041
2042 tcp_outgoing_address 2001:db8::c001 good_service_net
2043 tcp_outgoing_address 10.1.0.2 good_service_net
2044
2045 tcp_outgoing_address 2001:db8::beef normal_service_net
2046 tcp_outgoing_address 10.1.0.1 normal_service_net
2047
2048 tcp_outgoing_address 2001:db8::1
2049 tcp_outgoing_address 10.1.0.3
2050
2051 Processing proceeds in the order specified, and stops at first fully
2052 matching line.
2053
2054 Squid will add an implicit IP version test to each line.
2055 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2056 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2057
2058
2059 NOTE: The use of this directive using client dependent ACLs is
2060 incompatible with the use of server side persistent connections. To
2061 ensure correct results it is best to set server_persistent_connections
2062 to off when using this directive in such configurations.
2063
2064 NOTE: The use of this directive to set a local IP on outgoing TCP links
2065 is incompatible with using TPROXY to set client IP out outbound TCP links.
2066 When needing to contact peers use the no-tproxy cache_peer option and the
2067 client_dst_passthru directive re-enable normal forwarding such as this.
2068
2069DOC_END
2070
2071NAME: host_verify_strict
2072TYPE: onoff
2073DEFAULT: off
2074LOC: Config.onoff.hostStrictVerify
2075DOC_START
2076 Regardless of this option setting, when dealing with intercepted
2077 traffic, Squid always verifies that the destination IP address matches
2078 the Host header domain or IP (called 'authority form URL').
2079
2080 This enforcement is performed to satisfy a MUST-level requirement in
2081 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2082 authority of the origin server or gateway given by the original URL".
2083
2084 When set to ON:
2085 Squid always responds with an HTTP 409 (Conflict) error
2086 page and logs a security warning if there is no match.
2087
2088 Squid verifies that the destination IP address matches
2089 the Host header for forward-proxy and reverse-proxy traffic
2090 as well. For those traffic types, Squid also enables the
2091 following checks, comparing the corresponding Host header
2092 and Request-URI components:
2093
2094 * The host names (domain or IP) must be identical,
2095 but valueless or missing Host header disables all checks.
2096 For the two host names to match, both must be either IP
2097 or FQDN.
2098
2099 * Port numbers must be identical, but if a port is missing
2100 the scheme-default port is assumed.
2101
2102
2103 When set to OFF (the default):
2104 Squid allows suspicious requests to continue but logs a
2105 security warning and blocks caching of the response.
2106
2107 * Forward-proxy traffic is not checked at all.
2108
2109 * Reverse-proxy traffic is not checked at all.
2110
2111 * Intercepted traffic which passes verification is handled
2112 according to client_dst_passthru.
2113
2114 * Intercepted requests which fail verification are sent
2115 to the client original destination instead of DIRECT.
2116 This overrides 'client_dst_passthru off'.
2117
2118 For now suspicious intercepted CONNECT requests are always
2119 responded to with an HTTP 409 (Conflict) error page.
2120
2121
2122 SECURITY NOTE:
2123
2124 As described in CVE-2009-0801 when the Host: header alone is used
2125 to determine the destination of a request it becomes trivial for
2126 malicious scripts on remote websites to bypass browser same-origin
2127 security policy and sandboxing protections.
2128
2129 The cause of this is that such applets are allowed to perform their
2130 own HTTP stack, in which case the same-origin policy of the browser
2131 sandbox only verifies that the applet tries to contact the same IP
2132 as from where it was loaded at the IP level. The Host: header may
2133 be different from the connected IP and approved origin.
2134
2135DOC_END
2136
2137NAME: client_dst_passthru
2138TYPE: onoff
2139DEFAULT: on
2140LOC: Config.onoff.client_dst_passthru
2141DOC_START
2142 With NAT or TPROXY intercepted traffic Squid may pass the request
2143 directly to the original client destination IP or seek a faster
2144 source using the HTTP Host header.
2145
2146 Using Host to locate alternative servers can provide faster
2147 connectivity with a range of failure recovery options.
2148 But can also lead to connectivity trouble when the client and
2149 server are attempting stateful interactions unaware of the proxy.
2150
2151 This option (on by default) prevents alternative DNS entries being
2152 located to send intercepted traffic DIRECT to an origin server.
2153 The clients original destination IP and port will be used instead.
2154
2155 Regardless of this option setting, when dealing with intercepted
2156 traffic Squid will verify the Host: header and any traffic which
2157 fails Host verification will be treated as if this option were ON.
2158
2159 see host_verify_strict for details on the verification process.
2160DOC_END
2161
2162COMMENT_START
2163 SSL OPTIONS
2164 -----------------------------------------------------------------------------
2165COMMENT_END
2166
2167NAME: ssl_unclean_shutdown
2168IFDEF: USE_SSL
2169TYPE: onoff
2170DEFAULT: off
2171LOC: Config.SSL.unclean_shutdown
2172DOC_START
2173 Some browsers (especially MSIE) bugs out on SSL shutdown
2174 messages.
2175DOC_END
2176
2177NAME: ssl_engine
2178IFDEF: USE_SSL
2179TYPE: string
2180LOC: Config.SSL.ssl_engine
2181DEFAULT: none
2182DOC_START
2183 The OpenSSL engine to use. You will need to set this if you
2184 would like to use hardware SSL acceleration for example.
2185DOC_END
2186
2187NAME: sslproxy_client_certificate
2188IFDEF: USE_SSL
2189DEFAULT: none
2190LOC: Config.ssl_client.cert
2191TYPE: string
2192DOC_START
2193 Client SSL Certificate to use when proxying https:// URLs
2194DOC_END
2195
2196NAME: sslproxy_client_key
2197IFDEF: USE_SSL
2198DEFAULT: none
2199LOC: Config.ssl_client.key
2200TYPE: string
2201DOC_START
2202 Client SSL Key to use when proxying https:// URLs
2203DOC_END
2204
2205NAME: sslproxy_version
2206IFDEF: USE_SSL
2207DEFAULT: 1
2208DEFAULT_DOC: automatic SSL/TLS version negotiation
2209LOC: Config.ssl_client.version
2210TYPE: int
2211DOC_START
2212 SSL version level to use when proxying https:// URLs
2213
2214 The versions of SSL/TLS supported:
2215
2216 1 automatic (default)
2217 2 SSLv2 only
2218 3 SSLv3 only
2219 4 TLSv1.0 only
2220 5 TLSv1.1 only
2221 6 TLSv1.2 only
2222DOC_END
2223
2224NAME: sslproxy_options
2225IFDEF: USE_SSL
2226DEFAULT: none
2227LOC: Config.ssl_client.options
2228TYPE: string
2229DOC_START
2230 SSL implementation options to use when proxying https:// URLs
2231
2232 The most important being:
2233
2234 NO_SSLv2 Disallow the use of SSLv2
2235 NO_SSLv3 Disallow the use of SSLv3
2236 NO_TLSv1 Disallow the use of TLSv1.0
2237 NO_TLSv1_1 Disallow the use of TLSv1.1
2238 NO_TLSv1_2 Disallow the use of TLSv1.2
2239 SINGLE_DH_USE
2240 Always create a new key when using temporary/ephemeral
2241 DH key exchanges
2242 SSL_OP_NO_TICKET
2243 Disable use of RFC5077 session tickets. Some servers
2244 may have problems understanding the TLS extension due
2245 to ambiguous specification in RFC4507.
2246 ALL Enable various bug workarounds suggested as "harmless"
2247 by OpenSSL. Be warned that this may reduce SSL/TLS
2248 strength to some attacks.
2249
2250 See the OpenSSL SSL_CTX_set_options documentation for a
2251 complete list of possible options.
2252DOC_END
2253
2254NAME: sslproxy_cipher
2255IFDEF: USE_SSL
2256DEFAULT: none
2257LOC: Config.ssl_client.cipher
2258TYPE: string
2259DOC_START
2260 SSL cipher list to use when proxying https:// URLs
2261
2262 Colon separated list of supported ciphers.
2263DOC_END
2264
2265NAME: sslproxy_cafile
2266IFDEF: USE_SSL
2267DEFAULT: none
2268LOC: Config.ssl_client.cafile
2269TYPE: string
2270DOC_START
2271 file containing CA certificates to use when verifying server
2272 certificates while proxying https:// URLs
2273DOC_END
2274
2275NAME: sslproxy_capath
2276IFDEF: USE_SSL
2277DEFAULT: none
2278LOC: Config.ssl_client.capath
2279TYPE: string
2280DOC_START
2281 directory containing CA certificates to use when verifying
2282 server certificates while proxying https:// URLs
2283DOC_END
2284
2285NAME: ssl_bump
2286IFDEF: USE_SSL
2287TYPE: sslproxy_ssl_bump
2288LOC: Config.accessList.ssl_bump
2289DEFAULT_DOC: Does not bump unless rules are present in squid.conf
2290DEFAULT: none
2291DOC_START
2292 This option is consulted when a CONNECT request is received on
2293 an http_port (or a new connection is intercepted at an
2294 https_port), provided that port was configured with an ssl-bump
2295 flag. The subsequent data on the connection is either treated as
2296 HTTPS and decrypted OR tunneled at TCP level without decryption,
2297 depending on the first bumping "mode" which ACLs match.
2298
2299 ssl_bump <mode> [!]acl ...
2300
2301 The following bumping modes are supported:
2302
2303 client-first
2304 Allow bumping of the connection. Establish a secure connection
2305 with the client first, then connect to the server. This old mode
2306 does not allow Squid to mimic server SSL certificate and does
2307 not work with intercepted SSL connections.
2308
2309 server-first
2310 Allow bumping of the connection. Establish a secure connection
2311 with the server first, then establish a secure connection with
2312 the client, using a mimicked server certificate. Works with both
2313 CONNECT requests and intercepted SSL connections.
2314
2315 none
2316 Become a TCP tunnel without decoding the connection.
2317 Works with both CONNECT requests and intercepted SSL
2318 connections. This is the default behavior when no
2319 ssl_bump option is given or no ssl_bump ACLs match.
2320
2321 By default, no connections are bumped.
2322
2323 The first matching ssl_bump option wins. If no ACLs match, the
2324 connection is not bumped. Unlike most allow/deny ACL lists, ssl_bump
2325 does not have an implicit "negate the last given option" rule. You
2326 must make that rule explicit if you convert old ssl_bump allow/deny
2327 rules that rely on such an implicit rule.
2328
2329 This clause supports both fast and slow acl types.
2330 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2331
2332 See also: http_port ssl-bump, https_port ssl-bump
2333
2334
2335 # Example: Bump all requests except those originating from
2336 # localhost or those going to example.com.
2337
2338 acl broken_sites dstdomain .example.com
2339 ssl_bump none localhost
2340 ssl_bump none broken_sites
2341 ssl_bump server-first all
2342DOC_END
2343
2344NAME: sslproxy_flags
2345IFDEF: USE_SSL
2346DEFAULT: none
2347LOC: Config.ssl_client.flags
2348TYPE: string
2349DOC_START
2350 Various flags modifying the use of SSL while proxying https:// URLs:
2351 DONT_VERIFY_PEER Accept certificates that fail verification.
2352 For refined control, see sslproxy_cert_error.
2353 NO_DEFAULT_CA Don't use the default CA list built in
2354 to OpenSSL.
2355DOC_END
2356
2357NAME: sslproxy_cert_error
2358IFDEF: USE_SSL
2359DEFAULT: none
2360DEFAULT_DOC: Server certificate errors terminate the transaction.
2361LOC: Config.ssl_client.cert_error
2362TYPE: acl_access
2363DOC_START
2364 Use this ACL to bypass server certificate validation errors.
2365
2366 For example, the following lines will bypass all validation errors
2367 when talking to servers for example.com. All other
2368 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2369
2370 acl BrokenButTrustedServers dstdomain example.com
2371 sslproxy_cert_error allow BrokenButTrustedServers
2372 sslproxy_cert_error deny all
2373
2374 This clause only supports fast acl types.
2375 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2376 Using slow acl types may result in server crashes
2377
2378 Without this option, all server certificate validation errors
2379 terminate the transaction to protect Squid and the client.
2380
2381 SECURITY WARNING:
2382 Bypassing validation errors is dangerous because an
2383 error usually implies that the server cannot be trusted
2384 and the connection may be insecure.
2385
2386 See also: sslproxy_flags and DONT_VERIFY_PEER.
2387DOC_END
2388
2389NAME: sslproxy_cert_sign
2390IFDEF: USE_SSL
2391DEFAULT: none
2392POSTSCRIPTUM: signUntrusted ssl::certUntrusted
2393POSTSCRIPTUM: signSelf ssl::certSelfSigned
2394POSTSCRIPTUM: signTrusted all
2395TYPE: sslproxy_cert_sign
2396LOC: Config.ssl_client.cert_sign
2397DOC_START
2398
2399 sslproxy_cert_sign <signing algorithm> acl ...
2400
2401 The following certificate signing algorithms are supported:
2402
2403 signTrusted
2404 Sign using the configured CA certificate which is usually
2405 placed in and trusted by end-user browsers. This is the
2406 default for trusted origin server certificates.
2407
2408 signUntrusted
2409 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2410 This is the default for untrusted origin server certificates
2411 that are not self-signed (see ssl::certUntrusted).
2412
2413 signSelf
2414 Sign using a self-signed certificate with the right CN to
2415 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2416 browser. This is the default for self-signed origin server
2417 certificates (see ssl::certSelfSigned).
2418
2419 This clause only supports fast acl types.
2420
2421 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2422 signing algorithm to generate the certificate and ignores all
2423 subsequent sslproxy_cert_sign options (the first match wins). If no
2424 acl(s) match, the default signing algorithm is determined by errors
2425 detected when obtaining and validating the origin server certificate.
2426
2427 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2428 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2429 CONNECT request that carries a domain name. In all other cases (CONNECT
2430 to an IP address or an intercepted SSL connection), Squid cannot detect
2431 the domain mismatch at certificate generation time when
2432 bump-server-first is used.
2433DOC_END
2434
2435NAME: sslproxy_cert_adapt
2436IFDEF: USE_SSL
2437DEFAULT: none
2438TYPE: sslproxy_cert_adapt
2439LOC: Config.ssl_client.cert_adapt
2440DOC_START
2441
2442 sslproxy_cert_adapt <adaptation algorithm> acl ...
2443
2444 The following certificate adaptation algorithms are supported:
2445
2446 setValidAfter
2447 Sets the "Not After" property to the "Not After" property of
2448 the CA certificate used to sign generated certificates.
2449
2450 setValidBefore
2451 Sets the "Not Before" property to the "Not Before" property of
2452 the CA certificate used to sign generated certificates.
2453
2454 setCommonName or setCommonName{CN}
2455 Sets Subject.CN property to the host name specified as a
2456 CN parameter or, if no explicit CN parameter was specified,
2457 extracted from the CONNECT request. It is a misconfiguration
2458 to use setCommonName without an explicit parameter for
2459 intercepted or tproxied SSL connections.
2460
2461 This clause only supports fast acl types.
2462
2463 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2464 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2465 corresponding adaptation algorithm to generate the certificate and
2466 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2467 group (i.e., the first match wins within each algorithm group). If no
2468 acl(s) match, the default mimicking action takes place.
2469
2470 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2471 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2472 CONNECT request that carries a domain name. In all other cases (CONNECT
2473 to an IP address or an intercepted SSL connection), Squid cannot detect
2474 the domain mismatch at certificate generation time when
2475 bump-server-first is used.
2476DOC_END
2477
2478NAME: sslpassword_program
2479IFDEF: USE_SSL
2480DEFAULT: none
2481LOC: Config.Program.ssl_password
2482TYPE: string
2483DOC_START
2484 Specify a program used for entering SSL key passphrases
2485 when using encrypted SSL certificate keys. If not specified
2486 keys must either be unencrypted, or Squid started with the -N
2487 option to allow it to query interactively for the passphrase.
2488
2489 The key file name is given as argument to the program allowing
2490 selection of the right password if you have multiple encrypted
2491 keys.
2492DOC_END
2493
2494COMMENT_START
2495 OPTIONS RELATING TO EXTERNAL SSL_CRTD
2496 -----------------------------------------------------------------------------
2497COMMENT_END
2498
2499NAME: sslcrtd_program
2500TYPE: eol
2501IFDEF: USE_SSL_CRTD
2502DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
2503LOC: Ssl::TheConfig.ssl_crtd
2504DOC_START
2505 Specify the location and options of the executable for ssl_crtd process.
2506 @DEFAULT_SSL_CRTD@ program requires -s and -M parameters
2507 For more information use:
2508 @DEFAULT_SSL_CRTD@ -h
2509DOC_END
2510
2511NAME: sslcrtd_children
2512TYPE: HelperChildConfig
2513IFDEF: USE_SSL_CRTD
2514DEFAULT: 32 startup=5 idle=1
2515LOC: Ssl::TheConfig.ssl_crtdChildren
2516DOC_START
2517 The maximum number of processes spawn to service ssl server.
2518 The maximum this may be safely set to is 32.
2519
2520 The startup= and idle= options allow some measure of skew in your
2521 tuning.
2522
2523 startup=N
2524
2525 Sets the minimum number of processes to spawn when Squid
2526 starts or reconfigures. When set to zero the first request will
2527 cause spawning of the first child process to handle it.
2528
2529 Starting too few children temporary slows Squid under load while it
2530 tries to spawn enough additional processes to cope with traffic.
2531
2532 idle=N
2533
2534 Sets a minimum of how many processes Squid is to try and keep available
2535 at all times. When traffic begins to rise above what the existing
2536 processes can handle this many more will be spawned up to the maximum
2537 configured. A minimum setting of 1 is required.
2538
2539 You must have at least one ssl_crtd process.
2540DOC_END
2541
2542NAME: sslcrtvalidator_program
2543TYPE: eol
2544IFDEF: USE_SSL
2545DEFAULT: none
2546LOC: Ssl::TheConfig.ssl_crt_validator
2547DOC_START
2548 Specify the location and options of the executable for ssl_crt_validator
2549 process.
2550
2551 Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2552
2553 Options:
2554 ttl=n TTL in seconds for cached results. The default is 60 secs
2555 cache=n limit the result cache size. The default value is 2048
2556DOC_END
2557
2558NAME: sslcrtvalidator_children
2559TYPE: HelperChildConfig
2560IFDEF: USE_SSL
2561DEFAULT: 32 startup=5 idle=1 concurrency=1
2562LOC: Ssl::TheConfig.ssl_crt_validator_Children
2563DOC_START
2564 The maximum number of processes spawn to service SSL server.
2565 The maximum this may be safely set to is 32.
2566
2567 The startup= and idle= options allow some measure of skew in your
2568 tuning.
2569
2570 startup=N
2571
2572 Sets the minimum number of processes to spawn when Squid
2573 starts or reconfigures. When set to zero the first request will
2574 cause spawning of the first child process to handle it.
2575
2576 Starting too few children temporary slows Squid under load while it
2577 tries to spawn enough additional processes to cope with traffic.
2578
2579 idle=N
2580
2581 Sets a minimum of how many processes Squid is to try and keep available
2582 at all times. When traffic begins to rise above what the existing
2583 processes can handle this many more will be spawned up to the maximum
2584 configured. A minimum setting of 1 is required.
2585
2586 concurrency=
2587
2588 The number of requests each certificate validator helper can handle in
2589 parallel. Defaults to 0 which indicates the certficate validator
2590 is a old-style single threaded redirector.
2591
2592 When this directive is set to a value >= 1 then the protocol
2593 used to communicate with the helper is modified to include
2594 a request ID in front of the request/response. The request
2595 ID from the request must be echoed back with the response
2596 to that request.
2597
2598 You must have at least one ssl_crt_validator process.
2599DOC_END
2600
2601COMMENT_START
2602 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2603 -----------------------------------------------------------------------------
2604COMMENT_END
2605
2606NAME: cache_peer
2607TYPE: peer
2608DEFAULT: none
2609LOC: Config.peers
2610DOC_START
2611 To specify other caches in a hierarchy, use the format:
2612
2613 cache_peer hostname type http-port icp-port [options]
2614
2615 For example,
2616
2617 # proxy icp
2618 # hostname type port port options
2619 # -------------------- -------- ----- ----- -----------
2620 cache_peer parent.foo.net parent 3128 3130 default
2621 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2622 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2623 cache_peer example.com parent 80 0 default
2624 cache_peer cdn.example.com sibling 3128 0
2625
2626 type: either 'parent', 'sibling', or 'multicast'.
2627
2628 proxy-port: The port number where the peer accept HTTP requests.
2629 For other Squid proxies this is usually 3128
2630 For web servers this is usually 80
2631
2632 icp-port: Used for querying neighbor caches about objects.
2633 Set to 0 if the peer does not support ICP or HTCP.
2634 See ICP and HTCP options below for additional details.
2635
2636
2637 ==== ICP OPTIONS ====
2638
2639 You MUST also set icp_port and icp_access explicitly when using these options.
2640 The defaults will prevent peer traffic using ICP.
2641
2642
2643 no-query Disable ICP queries to this neighbor.
2644
2645 multicast-responder
2646 Indicates the named peer is a member of a multicast group.
2647 ICP queries will not be sent directly to the peer, but ICP
2648 replies will be accepted from it.
2649
2650 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2651 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2652
2653 background-ping
2654 To only send ICP queries to this neighbor infrequently.
2655 This is used to keep the neighbor round trip time updated
2656 and is usually used in conjunction with weighted-round-robin.
2657
2658
2659 ==== HTCP OPTIONS ====
2660
2661 You MUST also set htcp_port and htcp_access explicitly when using these options.
2662 The defaults will prevent peer traffic using HTCP.
2663
2664
2665 htcp Send HTCP, instead of ICP, queries to the neighbor.
2666 You probably also want to set the "icp-port" to 4827
2667 instead of 3130. This directive accepts a comma separated
2668 list of options described below.
2669
2670 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2671
2672 htcp=no-clr Send HTCP to the neighbor but without
2673 sending any CLR requests. This cannot be used with
2674 only-clr.
2675
2676 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2677 This cannot be used with no-clr.
2678
2679 htcp=no-purge-clr
2680 Send HTCP to the neighbor including CLRs but only when
2681 they do not result from PURGE requests.
2682
2683 htcp=forward-clr
2684 Forward any HTCP CLR requests this proxy receives to the peer.
2685
2686
2687 ==== PEER SELECTION METHODS ====
2688
2689 The default peer selection method is ICP, with the first responding peer
2690 being used as source. These options can be used for better load balancing.
2691
2692
2693 default This is a parent cache which can be used as a "last-resort"
2694 if a peer cannot be located by any of the peer-selection methods.
2695 If specified more than once, only the first is used.
2696
2697 round-robin Load-Balance parents which should be used in a round-robin
2698 fashion in the absence of any ICP queries.
2699 weight=N can be used to add bias.
2700
2701 weighted-round-robin
2702 Load-Balance parents which should be used in a round-robin
2703 fashion with the frequency of each parent being based on the
2704 round trip time. Closer parents are used more often.
2705 Usually used for background-ping parents.
2706 weight=N can be used to add bias.
2707
2708 carp Load-Balance parents which should be used as a CARP array.
2709 The requests will be distributed among the parents based on the
2710 CARP load balancing hash function based on their weight.
2711
2712 userhash Load-balance parents based on the client proxy_auth or ident username.
2713
2714 sourcehash Load-balance parents based on the client source IP.
2715
2716 multicast-siblings
2717 To be used only for cache peers of type "multicast".
2718 ALL members of this multicast group have "sibling"
2719 relationship with it, not "parent". This is to a multicast
2720 group when the requested object would be fetched only from
2721 a "parent" cache, anyway. It's useful, e.g., when
2722 configuring a pool of redundant Squid proxies, being
2723 members of the same multicast group.
2724
2725
2726 ==== PEER SELECTION OPTIONS ====
2727
2728 weight=N use to affect the selection of a peer during any weighted
2729 peer-selection mechanisms.
2730 The weight must be an integer; default is 1,
2731 larger weights are favored more.
2732 This option does not affect parent selection if a peering
2733 protocol is not in use.
2734
2735 basetime=N Specify a base amount to be subtracted from round trip
2736 times of parents.
2737 It is subtracted before division by weight in calculating
2738 which parent to fectch from. If the rtt is less than the
2739 base time the rtt is set to a minimal value.
2740
2741 ttl=N Specify a TTL to use when sending multicast ICP queries
2742 to this address.
2743 Only useful when sending to a multicast group.
2744 Because we don't accept ICP replies from random
2745 hosts, you must configure other group members as
2746 peers with the 'multicast-responder' option.
2747
2748 no-delay To prevent access to this neighbor from influencing the
2749 delay pools.
2750
2751 digest-url=URL Tell Squid to fetch the cache digest (if digests are
2752 enabled) for this host from the specified URL rather
2753 than the Squid default location.
2754
2755
2756 ==== CARP OPTIONS ====
2757
2758 carp-key=key-specification
2759 use a different key than the full URL to hash against the peer.
2760 the key-specification is a comma-separated list of the keywords
2761 scheme, host, port, path, params
2762 Order is not important.
2763
2764 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2765
2766 originserver Causes this parent to be contacted as an origin server.
2767 Meant to be used in accelerator setups when the peer
2768 is a web server.
2769
2770 forceddomain=name
2771 Set the Host header of requests forwarded to this peer.
2772 Useful in accelerator setups where the server (peer)
2773 expects a certain domain name but clients may request
2774 others. ie example.com or www.example.com
2775
2776 no-digest Disable request of cache digests.
2777
2778 no-netdb-exchange
2779 Disables requesting ICMP RTT database (NetDB).
2780
2781
2782 ==== AUTHENTICATION OPTIONS ====
2783
2784 login=user:password
2785 If this is a personal/workgroup proxy and your parent
2786 requires proxy authentication.
2787
2788 Note: The string can include URL escapes (i.e. %20 for
2789 spaces). This also means % must be written as %%.
2790
2791 login=PASSTHRU
2792 Send login details received from client to this peer.
2793 Both Proxy- and WWW-Authorization headers are passed
2794 without alteration to the peer.
2795 Authentication is not required by Squid for this to work.
2796
2797 Note: This will pass any form of authentication but
2798 only Basic auth will work through a proxy unless the
2799 connection-auth options are also used.
2800
2801 login=PASS Send login details received from client to this peer.
2802 Authentication is not required by this option.
2803
2804 If there are no client-provided authentication headers
2805 to pass on, but username and password are available
2806 from an external ACL user= and password= result tags
2807 they may be sent instead.
2808
2809 Note: To combine this with proxy_auth both proxies must
2810 share the same user database as HTTP only allows for
2811 a single login (one for proxy, one for origin server).
2812 Also be warned this will expose your users proxy
2813 password to the peer. USE WITH CAUTION
2814
2815 login=*:password
2816 Send the username to the upstream cache, but with a
2817 fixed password. This is meant to be used when the peer
2818 is in another administrative domain, but it is still
2819 needed to identify each user.
2820 The star can optionally be followed by some extra
2821 information which is added to the username. This can
2822 be used to identify this proxy to the peer, similar to
2823 the login=username:password option above.
2824
2825 login=NEGOTIATE
2826 If this is a personal/workgroup proxy and your parent
2827 requires a secure proxy authentication.
2828 The first principal from the default keytab or defined by
2829 the environment variable KRB5_KTNAME will be used.
2830
2831 WARNING: The connection may transmit requests from multiple
2832 clients. Negotiate often assumes end-to-end authentication
2833 and a single-client. Which is not strictly true here.
2834
2835 login=NEGOTIATE:principal_name
2836 If this is a personal/workgroup proxy and your parent
2837 requires a secure proxy authentication.
2838 The principal principal_name from the default keytab or
2839 defined by the environment variable KRB5_KTNAME will be
2840 used.
2841
2842 WARNING: The connection may transmit requests from multiple
2843 clients. Negotiate often assumes end-to-end authentication
2844 and a single-client. Which is not strictly true here.
2845
2846 connection-auth=on|off
2847 Tell Squid that this peer does or not support Microsoft
2848 connection oriented authentication, and any such
2849 challenges received from there should be ignored.
2850 Default is auto to automatically determine the status
2851 of the peer.
2852
2853
2854 ==== SSL / HTTPS / TLS OPTIONS ====
2855
2856 ssl Encrypt connections to this peer with SSL/TLS.
2857
2858 sslcert=/path/to/ssl/certificate
2859 A client SSL certificate to use when connecting to
2860 this peer.
2861
2862 sslkey=/path/to/ssl/key
2863 The private SSL key corresponding to sslcert above.
2864 If 'sslkey' is not specified 'sslcert' is assumed to
2865 reference a combined file containing both the
2866 certificate and the key.
2867
2868 sslversion=1|2|3|4|5|6
2869 The SSL version to use when connecting to this peer
2870 1 = automatic (default)
2871 2 = SSL v2 only
2872 3 = SSL v3 only
2873 4 = TLS v1.0 only
2874 5 = TLS v1.1 only
2875 6 = TLS v1.2 only
2876
2877 sslcipher=... The list of valid SSL ciphers to use when connecting
2878 to this peer.
2879
2880 ssloptions=... Specify various SSL implementation options:
2881
2882 NO_SSLv2 Disallow the use of SSLv2
2883 NO_SSLv3 Disallow the use of SSLv3
2884 NO_TLSv1 Disallow the use of TLSv1.0
2885 NO_TLSv1_1 Disallow the use of TLSv1.1
2886 NO_TLSv1_2 Disallow the use of TLSv1.2
2887 SINGLE_DH_USE
2888 Always create a new key when using
2889 temporary/ephemeral DH key exchanges
2890 ALL Enable various bug workarounds
2891 suggested as "harmless" by OpenSSL
2892 Be warned that this reduces SSL/TLS
2893 strength to some attacks.
2894
2895 See the OpenSSL SSL_CTX_set_options documentation for a
2896 more complete list.
2897
2898 sslcafile=... A file containing additional CA certificates to use
2899 when verifying the peer certificate.
2900
2901 sslcapath=... A directory containing additional CA certificates to
2902 use when verifying the peer certificate.
2903
2904 sslcrlfile=... A certificate revocation list file to use when
2905 verifying the peer certificate.
2906
2907 sslflags=... Specify various flags modifying the SSL implementation:
2908
2909 DONT_VERIFY_PEER
2910 Accept certificates even if they fail to
2911 verify.
2912 NO_DEFAULT_CA
2913 Don't use the default CA list built in
2914 to OpenSSL.
2915 DONT_VERIFY_DOMAIN
2916 Don't verify the peer certificate
2917 matches the server name
2918
2919 ssldomain= The peer name as advertised in it's certificate.
2920 Used for verifying the correctness of the received peer
2921 certificate. If not specified the peer hostname will be
2922 used.
2923
2924 front-end-https
2925 Enable the "Front-End-Https: On" header needed when
2926 using Squid as a SSL frontend in front of Microsoft OWA.
2927 See MS KB document Q307347 for details on this header.
2928 If set to auto the header will only be added if the
2929 request is forwarded as a https:// URL.
2930
2931
2932 ==== GENERAL OPTIONS ====
2933
2934 connect-timeout=N
2935 A peer-specific connect timeout.
2936 Also see the peer_connect_timeout directive.
2937
2938 connect-fail-limit=N
2939 How many times connecting to a peer must fail before
2940 it is marked as down. Default is 10.
2941
2942 allow-miss Disable Squid's use of only-if-cached when forwarding
2943 requests to siblings. This is primarily useful when
2944 icp_hit_stale is used by the sibling. To extensive use
2945 of this option may result in forwarding loops, and you
2946 should avoid having two-way peerings with this option.
2947 For example to deny peer usage on requests from peer
2948 by denying cache_peer_access if the source is a peer.
2949
2950 max-conn=N Limit the amount of connections Squid may open to this
2951 peer. see also
2952
2953 name=xxx Unique name for the peer.
2954 Required if you have multiple peers on the same host
2955 but different ports.
2956 This name can be used in cache_peer_access and similar
2957 directives to dentify the peer.
2958 Can be used by outgoing access controls through the
2959 peername ACL type.
2960
2961 no-tproxy Do not use the client-spoof TPROXY support when forwarding
2962 requests to this peer. Use normal address selection instead.
2963
2964 proxy-only objects fetched from the peer will not be stored locally.
2965
2966DOC_END
2967
2968NAME: cache_peer_domain cache_host_domain
2969TYPE: hostdomain
2970DEFAULT: none
2971LOC: none
2972DOC_START
2973 Use to limit the domains for which a neighbor cache will be
2974 queried.
2975
2976 Usage:
2977 cache_peer_domain cache-host domain [domain ...]
2978 cache_peer_domain cache-host !domain
2979
2980 For example, specifying
2981
2982 cache_peer_domain parent.foo.net .edu
2983
2984 has the effect such that UDP query packets are sent to
2985 'bigserver' only when the requested object exists on a
2986 server in the .edu domain. Prefixing the domainname
2987 with '!' means the cache will be queried for objects
2988 NOT in that domain.
2989
2990 NOTE: * Any number of domains may be given for a cache-host,
2991 either on the same or separate lines.
2992 * When multiple domains are given for a particular
2993 cache-host, the first matched domain is applied.
2994 * Cache hosts with no domain restrictions are queried
2995 for all requests.
2996 * There are no defaults.
2997 * There is also a 'cache_peer_access' tag in the ACL
2998 section.
2999DOC_END
3000
3001NAME: cache_peer_access
3002TYPE: peer_access
3003DEFAULT: none
3004LOC: none
3005DOC_START
3006 Similar to 'cache_peer_domain' but provides more flexibility by
3007 using ACL elements.
3008
3009 Usage:
3010 cache_peer_access cache-host allow|deny [!]aclname ...
3011
3012 The syntax is identical to 'http_access' and the other lists of
3013 ACL elements. See the comments for 'http_access' below, or
3014 the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
3015DOC_END
3016
3017NAME: neighbor_type_domain
3018TYPE: hostdomaintype
3019DEFAULT: none
3020DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
3021LOC: none
3022DOC_START
3023 Modify the cache_peer neighbor type when passing requests
3024 about specific domains to the peer.
3025
3026 Usage:
3027 neighbor_type_domain neighbor parent|sibling domain domain ...
3028
3029 For example:
3030 cache_peer foo.example.com parent 3128 3130
3031 neighbor_type_domain foo.example.com sibling .au .de
3032
3033 The above configuration treats all requests to foo.example.com as a
3034 parent proxy unless the request is for a .au or .de ccTLD domain name.
3035DOC_END
3036
3037NAME: dead_peer_timeout
3038COMMENT: (seconds)
3039DEFAULT: 10 seconds
3040TYPE: time_t
3041LOC: Config.Timeout.deadPeer
3042DOC_START
3043 This controls how long Squid waits to declare a peer cache
3044 as "dead." If there are no ICP replies received in this
3045 amount of time, Squid will declare the peer dead and not
3046 expect to receive any further ICP replies. However, it
3047 continues to send ICP queries, and will mark the peer as
3048 alive upon receipt of the first subsequent ICP reply.
3049
3050 This timeout also affects when Squid expects to receive ICP
3051 replies from peers. If more than 'dead_peer' seconds have
3052 passed since the last ICP reply was received, Squid will not
3053 expect to receive an ICP reply on the next query. Thus, if
3054 your time between requests is greater than this timeout, you
3055 will see a lot of requests sent DIRECT to origin servers
3056 instead of to your parents.
3057DOC_END
3058
3059NAME: forward_max_tries
3060DEFAULT: 10
3061TYPE: int
3062LOC: Config.forward_max_tries
3063DOC_START
3064 Controls how many different forward paths Squid will try
3065 before giving up. See also forward_timeout.
3066
3067 NOTE: connect_retries (default: none) can make each of these
3068 possible forwarding paths be tried multiple times.
3069DOC_END
3070
3071NAME: hierarchy_stoplist
3072TYPE: wordlist
3073DEFAULT: none
3074LOC: Config.hierarchy_stoplist
3075DOC_START
3076 A list of words which, if found in a URL, cause the object to
3077 be handled directly by this cache. In other words, use this
3078 to not query neighbor caches for certain objects. You may
3079 list this option multiple times.
3080
3081 Example:
3082 hierarchy_stoplist cgi-bin ?
3083
3084 Note: never_direct overrides this option.
3085DOC_END
3086
3087COMMENT_START
3088 MEMORY CACHE OPTIONS
3089 -----------------------------------------------------------------------------
3090COMMENT_END
3091
3092NAME: cache_mem
3093COMMENT: (bytes)
3094TYPE: b_size_t
3095DEFAULT: 256 MB
3096LOC: Config.memMaxSize
3097DOC_START
3098 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3099 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3100 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3101 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3102
3103 'cache_mem' specifies the ideal amount of memory to be used
3104 for:
3105 * In-Transit objects
3106 * Hot Objects
3107 * Negative-Cached objects
3108
3109 Data for these objects are stored in 4 KB blocks. This
3110 parameter specifies the ideal upper limit on the total size of
3111 4 KB blocks allocated. In-Transit objects take the highest
3112 priority.
3113
3114 In-transit objects have priority over the others. When
3115 additional space is needed for incoming data, negative-cached
3116 and hot objects will be released. In other words, the
3117 negative-cached and hot objects will fill up any unused space
3118 not needed for in-transit objects.
3119
3120 If circumstances require, this limit will be exceeded.
3121 Specifically, if your incoming request rate requires more than
3122 'cache_mem' of memory to hold in-transit objects, Squid will
3123 exceed this limit to satisfy the new requests. When the load
3124 decreases, blocks will be freed until the high-water mark is
3125 reached. Thereafter, blocks will be used to store hot
3126 objects.
3127
3128 If shared memory caching is enabled, Squid does not use the shared
3129 cache space for in-transit objects, but they still consume as much
3130 local memory as they need. For more details about the shared memory
3131 cache, see memory_cache_shared.
3132DOC_END
3133
3134NAME: maximum_object_size_in_memory
3135COMMENT: (bytes)
3136TYPE: b_size_t
3137DEFAULT: 512 KB
3138LOC: Config.Store.maxInMemObjSize
3139DOC_START
3140 Objects greater than this size will not be attempted to kept in
3141 the memory cache. This should be set high enough to keep objects
3142 accessed frequently in memory to improve performance whilst low
3143 enough to keep larger objects from hoarding cache_mem.
3144DOC_END
3145
3146NAME: memory_cache_shared
3147COMMENT: on|off
3148TYPE: YesNoNone
3149LOC: Config.memShared
3150DEFAULT: none
3151DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
3152DOC_START
3153 Controls whether the memory cache is shared among SMP workers.
3154
3155 The shared memory cache is meant to occupy cache_mem bytes and replace
3156 the non-shared memory cache, although some entities may still be
3157 cached locally by workers for now (e.g., internal and in-transit
3158 objects may be served from a local memory cache even if shared memory
3159 caching is enabled).
3160
3161 By default, the memory cache is shared if and only if all of the
3162 following conditions are satisfied: Squid runs in SMP mode with
3163 multiple workers, cache_mem is positive, and Squid environment
3164 supports required IPC primitives (e.g., POSIX shared memory segments
3165 and GCC-style atomic operations).
3166
3167 To avoid blocking locks, shared memory uses opportunistic algorithms
3168 that do not guarantee that every cachable entity that could have been
3169 shared among SMP workers will actually be shared.
3170
3171 Currently, entities exceeding 32KB in size cannot be shared.
3172DOC_END
3173
3174NAME: memory_cache_mode
3175TYPE: memcachemode
3176LOC: Config
3177DEFAULT: always
3178DEFAULT_DOC: Keep the most recently fetched objects in memory
3179DOC_START
3180 Controls which objects to keep in the memory cache (cache_mem)
3181
3182 always Keep most recently fetched objects in memory (default)
3183
3184 disk Only disk cache hits are kept in memory, which means
3185 an object must first be cached on disk and then hit
3186 a second time before cached in memory.
3187
3188 network Only objects fetched from network is kept in memory
3189DOC_END
3190
3191NAME: memory_replacement_policy
3192TYPE: removalpolicy
3193LOC: Config.memPolicy
3194DEFAULT: lru
3195DOC_START
3196 The memory replacement policy parameter determines which
3197 objects are purged from memory when memory space is needed.
3198
3199 See cache_replacement_policy for details on algorithms.
3200DOC_END
3201
3202COMMENT_START
3203 DISK CACHE OPTIONS
3204 -----------------------------------------------------------------------------
3205COMMENT_END
3206
3207NAME: cache_replacement_policy
3208TYPE: removalpolicy
3209LOC: Config.replPolicy
3210DEFAULT: lru
3211DOC_START
3212 The cache replacement policy parameter determines which
3213 objects are evicted (replaced) when disk space is needed.
3214
3215 lru : Squid's original list based LRU policy
3216 heap GDSF : Greedy-Dual Size Frequency
3217 heap LFUDA: Least Frequently Used with Dynamic Aging
3218 heap LRU : LRU policy implemented using a heap
3219
3220 Applies to any cache_dir lines listed below this directive.
3221
3222 The LRU policies keeps recently referenced objects.
3223
3224 The heap GDSF policy optimizes object hit rate by keeping smaller
3225 popular objects in cache so it has a better chance of getting a
3226 hit. It achieves a lower byte hit rate than LFUDA though since
3227 it evicts larger (possibly popular) objects.
3228
3229 The heap LFUDA policy keeps popular objects in cache regardless of
3230 their size and thus optimizes byte hit rate at the expense of
3231 hit rate since one large, popular object will prevent many
3232 smaller, slightly less popular objects from being cached.
3233
3234 Both policies utilize a dynamic aging mechanism that prevents
3235 cache pollution that can otherwise occur with frequency-based
3236 replacement policies.
3237
3238 NOTE: if using the LFUDA replacement policy you should increase
3239 the value of maximum_object_size above its default of 4 MB to
3240 to maximize the potential byte hit rate improvement of LFUDA.
3241
3242 For more information about the GDSF and LFUDA cache replacement
3243 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3244 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3245DOC_END
3246
3247NAME: cache_dir
3248TYPE: cachedir
3249DEFAULT: none
3250DEFAULT_DOC: No disk cache. Store cache ojects only in memory.
3251LOC: Config.cacheSwap
3252DOC_START
3253 Format:
3254 cache_dir Type Directory-Name Fs-specific-data [options]
3255
3256 You can specify multiple cache_dir lines to spread the
3257 cache among different disk partitions.
3258
3259 Type specifies the kind of storage system to use. Only "ufs"
3260 is built by default. To enable any of the other storage systems
3261 see the --enable-storeio configure option.
3262
3263 'Directory' is a top-level directory where cache swap
3264 files will be stored. If you want to use an entire disk
3265 for caching, this can be the mount-point directory.
3266 The directory must exist and be writable by the Squid
3267 process. Squid will NOT create this directory for you.
3268
3269 In SMP configurations, cache_dir must not precede the workers option
3270 and should use configuration macros or conditionals to give each
3271 worker interested in disk caching a dedicated cache directory.
3272
3273
3274 ==== The ufs store type ====
3275
3276 "ufs" is the old well-known Squid storage format that has always
3277 been there.
3278
3279 Usage:
3280 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3281
3282 'Mbytes' is the amount of disk space (MB) to use under this
3283 directory. The default is 100 MB. Change this to suit your
3284 configuration. Do NOT put the size of your disk drive here.
3285 Instead, if you want Squid to use the entire disk drive,
3286 subtract 20% and use that value.
3287
3288 'L1' is the number of first-level subdirectories which
3289 will be created under the 'Directory'. The default is 16.
3290
3291 'L2' is the number of second-level subdirectories which
3292 will be created under each first-level directory. The default
3293 is 256.
3294
3295
3296 ==== The aufs store type ====
3297
3298 "aufs" uses the same storage format as "ufs", utilizing
3299 POSIX-threads to avoid blocking the main Squid process on
3300 disk-I/O. This was formerly known in Squid as async-io.
3301
3302 Usage:
3303 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3304
3305 see argument descriptions under ufs above
3306
3307
3308 ==== The diskd store type ====
3309
3310 "diskd" uses the same storage format as "ufs", utilizing a
3311 separate process to avoid blocking the main Squid process on
3312 disk-I/O.
3313
3314 Usage:
3315 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3316
3317 see argument descriptions under ufs above
3318
3319 Q1 specifies the number of unacknowledged I/O requests when Squid
3320 stops opening new files. If this many messages are in the queues,
3321 Squid won't open new files. Default is 64
3322
3323 Q2 specifies the number of unacknowledged messages when Squid
3324 starts blocking. If this many messages are in the queues,
3325 Squid blocks until it receives some replies. Default is 72
3326
3327 When Q1 < Q2 (the default), the cache directory is optimized
3328 for lower response time at the expense of a decrease in hit
3329 ratio. If Q1 > Q2, the cache directory is optimized for
3330 higher hit ratio at the expense of an increase in response
3331 time.
3332
3333
3334 ==== The rock store type ====
3335
3336 Usage:
3337 cache_dir rock Directory-Name Mbytes <max-size=bytes> [options]
3338
3339 The Rock Store type is a database-style storage. All cached
3340 entries are stored in a "database" file, using fixed-size slots,
3341 one entry per slot. The database size is specified in MB. The
3342 slot size is specified in bytes using the max-size option. See
3343 below for more info on the max-size option.
3344
3345 If possible, Squid using Rock Store creates a dedicated kid
3346 process called "disker" to avoid blocking Squid worker(s) on disk
3347 I/O. One disker kid is created for each rock cache_dir. Diskers
3348 are created only when Squid, running in daemon mode, has support
3349 for the IpcIo disk I/O module.
3350
3351 swap-timeout=msec: Squid will not start writing a miss to or
3352 reading a hit from disk if it estimates that the swap operation
3353 will take more than the specified number of milliseconds. By
3354 default and when set to zero, disables the disk I/O time limit
3355 enforcement. Ignored when using blocking I/O module because
3356 blocking synchronous I/O does not allow Squid to estimate the
3357 expected swap wait time.
3358
3359 max-swap-rate=swaps/sec: Artificially limits disk access using
3360 the specified I/O rate limit. Swap out requests that
3361 would cause the average I/O rate to exceed the limit are
3362 delayed. Individual swap in requests (i.e., hits or reads) are
3363 not delayed, but they do contribute to measured swap rate and
3364 since they are placed in the same FIFO queue as swap out
3365 requests, they may wait longer if max-swap-rate is smaller.
3366 This is necessary on file systems that buffer "too
3367 many" writes and then start blocking Squid and other processes
3368 while committing those writes to disk. Usually used together
3369 with swap-timeout to avoid excessive delays and queue overflows
3370 when disk demand exceeds available disk "bandwidth". By default
3371 and when set to zero, disables the disk I/O rate limit
3372 enforcement. Currently supported by IpcIo module only.
3373
3374
3375 ==== The coss store type ====
3376
3377 NP: COSS filesystem in Squid-3 has been deemed too unstable for
3378 production use and has thus been removed from this release.
3379 We hope that it can be made usable again soon.
3380
3381 block-size=n defines the "block size" for COSS cache_dir's.
3382 Squid uses file numbers as block numbers. Since file numbers
3383 are limited to 24 bits, the block size determines the maximum
3384 size of the COSS partition. The default is 512 bytes, which
3385 leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
3386 you should not change the coss block size after Squid
3387 has written some objects to the cache_dir.
3388
3389 The coss file store has changed from 2.5. Now it uses a file
3390 called 'stripe' in the directory names in the config - and
3391 this will be created by squid -z.
3392
3393
3394 ==== COMMON OPTIONS ====
3395
3396 no-store no new objects should be stored to this cache_dir.
3397
3398 min-size=n the minimum object size in bytes this cache_dir
3399 will accept. It's used to restrict a cache_dir
3400 to only store large objects (e.g. AUFS) while
3401 other stores are optimized for smaller objects
3402 (e.g. COSS).
3403 Defaults to 0.
3404
3405 max-size=n the maximum object size in bytes this cache_dir
3406 supports.
3407 The value in maximum_object_size directive, sets
3408 a default unless more specific details are available
3409 about the cache_dir (ie a small store capacity).
3410
3411 Note: To make optimal use of the max-size limits you should order
3412 the cache_dir lines with the smallest max-size value first.
3413
3414 Note for coss, max-size must be less than COSS_MEMBUF_SZ,
3415 which can be changed with the --with-coss-membuf-size=N configure
3416 option.
3417
3418NOCOMMENT_START
3419
3420# Uncomment and adjust the following to add a disk cache directory.
3421#cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
3422NOCOMMENT_END
3423DOC_END
3424
3425NAME: store_dir_select_algorithm
3426TYPE: string
3427LOC: Config.store_dir_select_algorithm
3428DEFAULT: least-load
3429DOC_START
3430 How Squid selects which cache_dir to use when the response
3431 object will fit into more than one.
3432
3433 Regardless of which algorithm is used the cache_dir min-size
3434 and max-size parameters are obeyed. As such they can affect
3435 the selection algorithm by limiting the set of considered
3436 cache_dir.
3437
3438 Algorithms:
3439
3440 least-load
3441
3442 This algorithm is suited to caches with similar cache_dir
3443 sizes and disk speeds.
3444
3445 The disk with the least I/O pending is selected.
3446 When there are multiple disks with the same I/O load ranking
3447 the cache_dir with most available capacity is selected.
3448
3449 When a mix of cache_dir sizes are configured the faster disks
3450 have a naturally lower I/O loading and larger disks have more
3451 capacity. So space used to store objects and data throughput
3452 may be very unbalanced towards larger disks.
3453
3454
3455 round-robin
3456
3457 This algorithm is suited to caches with unequal cache_dir
3458 disk sizes.
3459
3460 Each cache_dir is selected in a rotation. The next suitable
3461 cache_dir is used.
3462
3463 Available cache_dir capacity is only considered in relation
3464 to whether the object will fit and meets the min-size and
3465 max-size parameters.
3466
3467 Disk I/O loading is only considered to prevent overload on slow
3468 disks. This algorithm does not spread objects by size, so any
3469 I/O loading per-disk may appear very unbalanced and volatile.
3470
3471DOC_END
3472
3473NAME: max_open_disk_fds
3474TYPE: int
3475LOC: Config.max_open_disk_fds
3476DEFAULT: 0
3477DEFAULT_DOC: no limit
3478DOC_START
3479 To avoid having disk as the I/O bottleneck Squid can optionally
3480 bypass the on-disk cache if more than this amount of disk file
3481 descriptors are open.
3482
3483 A value of 0 indicates no limit.
3484DOC_END
3485
3486NAME: minimum_object_size
3487COMMENT: (bytes)
3488TYPE: b_int64_t
3489DEFAULT: 0 KB
3490DEFAULT_DOC: no limit
3491LOC: Config.Store.minObjectSize
3492DOC_START
3493 Objects smaller than this size will NOT be saved on disk. The
3494 value is specified in bytes, and the default is 0 KB, which
3495 means all responses can be stored.
3496DOC_END
3497
3498NAME: maximum_object_size
3499COMMENT: (bytes)
3500TYPE: b_int64_t
3501DEFAULT: 4 MB
3502LOC: Config.Store.maxObjectSize
3503DOC_START
3504 The default limit on size of objects stored to disk.
3505 This size is used for cache_dir where max-size is not set.
3506 The value is specified in bytes, and the default is 4 MB.
3507
3508 If you wish to get a high BYTES hit ratio, you should probably
3509 increase this (one 32 MB object hit counts for 3200 10KB
3510 hits).
3511
3512 If you wish to increase hit ratio more than you want to
3513 save bandwidth you should leave this low.
3514
3515 NOTE: if using the LFUDA replacement policy you should increase
3516 this value to maximize the byte hit rate improvement of LFUDA!
3517 See replacement_policy below for a discussion of this policy.
3518DOC_END
3519
3520NAME: cache_swap_low
3521COMMENT: (percent, 0-100)
3522TYPE: int
3523DEFAULT: 90
3524LOC: Config.Swap.lowWaterMark
3525DOC_START
3526 The low-water mark for cache object replacement.
3527 Replacement begins when the swap (disk) usage is above the
3528 low-water mark and attempts to maintain utilization near the
3529 low-water mark. As swap utilization gets close to high-water
3530 mark object eviction becomes more aggressive. If utilization is
3531 close to the low-water mark less replacement is done each time.
3532
3533 Defaults are 90% and 95%. If you have a large cache, 5% could be
3534 hundreds of MB. If this is the case you may wish to set these
3535 numbers closer together.
3536
3537 See also cache_swap_high
3538DOC_END
3539
3540NAME: cache_swap_high
3541COMMENT: (percent, 0-100)
3542TYPE: int
3543DEFAULT: 95
3544LOC: Config.Swap.highWaterMark
3545DOC_START
3546 The high-water mark for cache object replacement.
3547 Replacement begins when the swap (disk) usage is above the
3548 low-water mark and attempts to maintain utilization near the
3549 low-water mark. As swap utilization gets close to high-water
3550 mark object eviction becomes more aggressive. If utilization is
3551 close to the low-water mark less replacement is done each time.
3552
3553 Defaults are 90% and 95%. If you have a large cache, 5% could be
3554 hundreds of MB. If this is the case you may wish to set these
3555 numbers closer together.
3556
3557 See also cache_swap_low
3558DOC_END
3559
3560COMMENT_START
3561 LOGFILE OPTIONS
3562 -----------------------------------------------------------------------------
3563COMMENT_END
3564
3565NAME: logformat
3566TYPE: logformat
3567LOC: Log::TheConfig
3568DEFAULT: none
3569DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
3570DOC_START
3571 Usage:
3572
3573 logformat <name> <format specification>
3574
3575 Defines an access log format.
3576
3577 The <format specification> is a string with embedded % format codes
3578
3579 % format codes all follow the same basic structure where all but
3580 the formatcode is optional. Output strings are automatically escaped
3581 as required according to their context and the output format
3582 modifiers are usually not needed, but can be specified if an explicit
3583 output format is desired.
3584
3585 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3586
3587 " output in quoted string format
3588 [ output in squid text log format as used by log_mime_hdrs
3589 # output in URL quoted format
3590 ' output as-is
3591
3592 - left aligned
3593
3594 width minimum and/or maximum field width:
3595 [width_min][.width_max]
3596 When minimum starts with 0, the field is zero-padded.
3597 String values exceeding maximum width are truncated.
3598
3599 {arg} argument such as header name etc
3600
3601 Format codes:
3602
3603 % a literal % character
3604 sn Unique sequence number per log line entry
3605 err_code The ID of an error response served by Squid or
3606 a similar internal error identifier.
3607 err_detail Additional err_code-dependent error information.
3608 note The meta header specified by the argument. Also
3609 logs the adaptation meta headers set by the
3610 adaptation_meta configuration parameter.
3611 If no argument given all meta headers logged.
3612
3613 Connection related format codes:
3614
3615 >a Client source IP address
3616 >A Client FQDN
3617 >p Client source port
3618 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3619 >la Local IP address the client connected to
3620 >lp Local port number the client connected to
3621
3622 la Local listening IP address the client connection was connected to.
3623 lp Local listening port number the client connection was connected to.
3624
3625 <a Server IP address of the last server or peer connection
3626 <A Server FQDN or peer name
3627 <p Server port number of the last server or peer connection
3628 <la Local IP address of the last server or peer connection
3629 <lp Local port number of the last server or peer connection
3630
3631 Time related format codes:
3632
3633 ts Seconds since epoch
3634 tu subsecond time (milliseconds)
3635 tl Local time. Optional strftime format argument
3636 default %d/%b/%Y:%H:%M:%S %z
3637 tg GMT time. Optional strftime format argument
3638 default %d/%b/%Y:%H:%M:%S %z
3639 tr Response time (milliseconds)
3640 dt Total time spent making DNS lookups (milliseconds)
3641
3642 Access Control related format codes:
3643
3644 et Tag returned by external acl
3645 ea Log string returned by external acl
3646 un User name (any available)
3647 ul User name from authentication
3648 ue User name from external acl helper
3649 ui User name from ident
3650 us User name from SSL
3651
3652 HTTP related format codes:
3653
3654 [http::]>h Original request header. Optional header name argument
3655 on the format header[:[separator]element]
3656 [http::]>ha The HTTP request headers after adaptation and redirection.
3657 Optional header name argument as for >h
3658 [http::]<h Reply header. Optional header name argument
3659 as for >h
3660 [http::]>Hs HTTP status code sent to the client
3661 [http::]<Hs HTTP status code received from the next hop
3662 [http::]<bs Number of HTTP-equivalent message body bytes
3663 received from the next hop, excluding chunked
3664 transfer encoding and control messages.
3665 Generated FTP/Gopher listings are treated as
3666 received bodies.
3667 [http::]mt MIME content type
3668 [http::]rm Request method (GET/POST etc)
3669 [http::]>rm Request method from client
3670 [http::]<rm Request method sent to server or peer
3671 [http::]ru Request URL from client (historic, filtered for logging)
3672 [http::]>ru Request URL from client
3673 [http::]<ru Request URL sent to server or peer
3674 [http::]rp Request URL-Path excluding hostname
3675 [http::]>rp Request URL-Path excluding hostname from client
3676 [http::]<rp Request URL-Path excluding hostname sento to server or peer
3677 [http::]rv Request protocol version
3678 [http::]>rv Request protocol version from client
3679 [http::]<rv Request protocol version sent to server or peer
3680 [http::]<st Sent reply size including HTTP headers
3681 [http::]>st Received request size including HTTP headers. In the
3682 case of chunked requests the chunked encoding metadata
3683 are not included
3684 [http::]>sh Received HTTP request headers size
3685 [http::]<sh Sent HTTP reply headers size
3686 [http::]st Request+Reply size including HTTP headers
3687 [http::]<sH Reply high offset sent
3688 [http::]<sS Upstream object size
3689 [http::]<pt Peer response time in milliseconds. The timer starts
3690 when the last request byte is sent to the next hop
3691 and stops when the last response byte is received.
3692 [http::]<tt Total server-side time in milliseconds. The timer
3693 starts with the first connect request (or write I/O)
3694 sent to the first selected peer. The timer stops
3695 with the last I/O with the last peer.
3696
3697 Squid handling related format codes:
3698
3699 Ss Squid request status (TCP_MISS etc)
3700 Sh Squid hierarchy status (DEFAULT_PARENT etc)
3701
3702 SSL-related format codes:
3703
3704 ssl::bump_mode SslBump decision for the transaction:
3705
3706 For CONNECT requests that initiated bumping of
3707 a connection and for any request received on
3708 an already bumped connection, Squid logs the
3709 corresponding SslBump mode ("server-first" or
3710 "client-first"). See the ssl_bump option for
3711 more information about these modes.
3712
3713 A "none" token is logged for requests that
3714 triggered "ssl_bump" ACL evaluation matching
3715 either a "none" rule or no rules at all.
3716
3717 In all other cases, a single dash ("-") is
3718 logged.
3719
3720 If ICAP is enabled, the following code becomes available (as
3721 well as ICAP log codes documented with the icap_log option):
3722
3723 icap::tt Total ICAP processing time for the HTTP
3724 transaction. The timer ticks when ICAP
3725 ACLs are checked and when ICAP
3726 transaction is in progress.
3727
3728 If adaptation is enabled the following three codes become available:
3729
3730 adapt::<last_h The header of the last ICAP response or
3731 meta-information from the last eCAP
3732 transaction related to the HTTP transaction.
3733 Like <h, accepts an optional header name
3734 argument.
3735
3736 adapt::sum_trs Summed adaptation transaction response
3737 times recorded as a comma-separated list in
3738 the order of transaction start time. Each time
3739 value is recorded as an integer number,
3740 representing response time of one or more
3741 adaptation (ICAP or eCAP) transaction in
3742 milliseconds. When a failed transaction is
3743 being retried or repeated, its time is not
3744 logged individually but added to the
3745 replacement (next) transaction. See also:
3746 adapt::all_trs.
3747
3748 adapt::all_trs All adaptation transaction response times.
3749 Same as adaptation_strs but response times of
3750 individual transactions are never added
3751 together. Instead, all transaction response
3752 times are recorded individually.
3753
3754 You can prefix adapt::*_trs format codes with adaptation
3755 service name in curly braces to record response time(s) specific
3756 to that service. For example: %{my_service}adapt::sum_trs
3757
3758 If SSL is enabled, the following formating codes become available:
3759
3760 %ssl::>cert_subject The Subject field of the received client
3761 SSL certificate or a dash ('-') if Squid has
3762 received an invalid/malformed certificate or
3763 no certificate at all. Consider encoding the
3764 logged value because Subject often has spaces.
3765
3766 %ssl::>cert_issuer The Issuer field of the received client
3767 SSL certificate or a dash ('-') if Squid has
3768 received an invalid/malformed certificate or
3769 no certificate at all. Consider encoding the
3770 logged value because Issuer often has spaces.
3771
3772 The default formats available (which do not need re-defining) are:
3773
3774logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
3775logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
3776logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
3777logformat referrer %ts.%03tu %>a %{Referer}>h %ru
3778logformat useragent %>a [%tl] "%{User-Agent}>h"
3779
3780 NOTE: When the log_mime_hdrs directive is set to ON.
3781 The squid, common and combined formats have a safely encoded copy
3782 of the mime headers appended to each line within a pair of brackets.
3783
3784 NOTE: The common and combined formats are not quite true to the Apache definition.
3785 The logs from Squid contain an extra status and hierarchy code appended.
3786
3787DOC_END
3788
3789NAME: access_log cache_access_log
3790TYPE: access_log
3791LOC: Config.Log.accesslogs
3792DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
3793DOC_START
3794 These files log client request activities. Has a line every HTTP or
3795 ICP request. The format is:
3796 access_log <module>:<place> [<logformat name> [acl acl ...]]
3797 access_log none [acl acl ...]]
3798
3799 Will log to the specified module:place using the specified format (which
3800 must be defined in a logformat directive) those entries which match
3801 ALL the acl's specified (which must be defined in acl clauses).
3802 If no acl is specified, all requests will be logged to this destination.
3803
3804 ===== Modules Currently available =====
3805
3806 none Do not log any requests matching these ACL.
3807 Do not specify Place or logformat name.
3808
3809 stdio Write each log line to disk immediately at the completion of
3810 each request.
3811 Place: the filename and path to be written.
3812
3813 daemon Very similar to stdio. But instead of writing to disk the log
3814 line is passed to a daemon helper for asychronous handling instead.
3815 Place: varies depending on the daemon.
3816
3817 log_file_daemon Place: the file name and path to be written.
3818
3819 syslog To log each request via syslog facility.
3820 Place: The syslog facility and priority level for these entries.
3821 Place Format: facility.priority
3822
3823 where facility could be any of:
3824 authpriv, daemon, local0 ... local7 or user.
3825
3826 And priority could be any of:
3827 err, warning, notice, info, debug.
3828
3829 udp To send each log line as text data to a UDP receiver.
3830 Place: The destination host name or IP and port.
3831 Place Format: //host:port
3832
3833 tcp To send each log line as text data to a TCP receiver.
3834 Place: The destination host name or IP and port.
3835 Place Format: //host:port
3836
3837 Default:
3838 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
3839DOC_END
3840
3841NAME: icap_log
3842TYPE: access_log
3843IFDEF: ICAP_CLIENT
3844LOC: Config.Log.icaplogs
3845DEFAULT: none
3846DOC_START
3847 ICAP log files record ICAP transaction summaries, one line per
3848 transaction.
3849
3850 The icap_log option format is:
3851 icap_log <filepath> [<logformat name> [acl acl ...]]
3852 icap_log none [acl acl ...]]
3853
3854 Please see access_log option documentation for details. The two
3855 kinds of logs share the overall configuration approach and many
3856 features.
3857
3858 ICAP processing of a single HTTP message or transaction may
3859 require multiple ICAP transactions. In such cases, multiple
3860 ICAP transaction log lines will correspond to a single access
3861 log line.
3862
3863 ICAP log uses logformat codes that make sense for an ICAP
3864 transaction. Header-related codes are applied to the HTTP header
3865 embedded in an ICAP server response, with the following caveats:
3866 For REQMOD, there is no HTTP response header unless the ICAP
3867 server performed request satisfaction. For RESPMOD, the HTTP
3868 request header is the header sent to the ICAP server. For
3869 OPTIONS, there are no HTTP headers.
3870
3871 The following format codes are also available for ICAP logs:
3872
3873 icap::<A ICAP server IP address. Similar to <A.
3874
3875 icap::<service_name ICAP service name from the icap_service
3876 option in Squid configuration file.
3877
3878 icap::ru ICAP Request-URI. Similar to ru.
3879
3880 icap::rm ICAP request method (REQMOD, RESPMOD, or
3881 OPTIONS). Similar to existing rm.
3882
3883 icap::>st Bytes sent to the ICAP server (TCP payload
3884 only; i.e., what Squid writes to the socket).
3885
3886 icap::<st Bytes received from the ICAP server (TCP
3887 payload only; i.e., what Squid reads from
3888 the socket).
3889
3890 icap::<bs Number of message body bytes received from the
3891 ICAP server. ICAP message body, if any, usually
3892 includes encapsulated HTTP message headers and
3893 possibly encapsulated HTTP message body. The
3894 HTTP body part is dechunked before its size is
3895 computed.
3896
3897 icap::tr Transaction response time (in
3898 milliseconds). The timer starts when
3899 the ICAP transaction is created and
3900 stops when the transaction is completed.
3901 Similar to tr.
3902
3903 icap::tio Transaction I/O time (in milliseconds). The
3904 timer starts when the first ICAP request
3905 byte is scheduled for sending. The timers
3906 stops when the last byte of the ICAP response
3907 is received.
3908
3909 icap::to Transaction outcome: ICAP_ERR* for all
3910 transaction errors, ICAP_OPT for OPTION
3911 transactions, ICAP_ECHO for 204
3912 responses, ICAP_MOD for message
3913 modification, and ICAP_SAT for request
3914 satisfaction. Similar to Ss.
3915
3916 icap::Hs ICAP response status code. Similar to Hs.
3917
3918 icap::>h ICAP request header(s). Similar to >h.
3919
3920 icap::<h ICAP response header(s). Similar to <h.
3921
3922 The default ICAP log format, which can be used without an explicit
3923 definition, is called icap_squid:
3924
3925logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
3926
3927 See also: logformat, log_icap, and %adapt::<last_h
3928DOC_END
3929
3930NAME: logfile_daemon
3931TYPE: string
3932DEFAULT: @DEFAULT_LOGFILED@
3933LOC: Log::TheConfig.logfile_daemon
3934DOC_START
3935 Specify the path to the logfile-writing daemon. This daemon is
3936 used to write the access and store logs, if configured.
3937
3938 Squid sends a number of commands to the log daemon:
3939 L<data>\n - logfile data
3940 R\n - rotate file
3941 T\n - truncate file
3942 O\n - reopen file
3943 F\n - flush file
3944 r<n>\n - set rotate count to <n>
3945 b<n>\n - 1 = buffer output, 0 = don't buffer output
3946
3947 No responses is expected.
3948DOC_END
3949
3950NAME: log_access
3951TYPE: acl_access
3952LOC: Config.accessList.log
3953DEFAULT: none
3954DEFAULT_DOC: Allow logging for all transactions.
3955COMMENT: allow|deny acl acl...
3956DOC_START
3957 This options allows you to control which requests gets logged
3958 to access.log (see access_log directive). Requests denied for
3959 logging will also not be accounted for in performance counters.
3960
3961 This clause only supports fast acl types.
3962 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3963DOC_END
3964
3965NAME: log_icap
3966TYPE: acl_access
3967IFDEF: ICAP_CLIENT
3968LOC: Config.accessList.icap
3969DEFAULT: none
3970DEFAULT_DOC: Allow logging for all ICAP transactions.
3971DOC_START
3972 This options allows you to control which requests get logged
3973 to icap.log. See the icap_log directive for ICAP log details.
3974DOC_END
3975
3976NAME: cache_store_log
3977TYPE: string
3978DEFAULT: none
3979LOC: Config.Log.store
3980DOC_START
3981 Logs the activities of the storage manager. Shows which
3982 objects are ejected from the cache, and which objects are
3983 saved and for how long.
3984 There are not really utilities to analyze this data, so you can safely
3985 disable it (the default).
3986
3987 Store log uses modular logging outputs. See access_log for the list
3988 of modules supported.
3989
3990 Example:
3991 cache_store_log stdio:@DEFAULT_STORE_LOG@
3992 cache_store_log daemon:@DEFAULT_STORE_LOG@
3993DOC_END
3994
3995NAME: cache_swap_state cache_swap_log
3996TYPE: string
3997LOC: Config.Log.swap
3998DEFAULT: none
3999DEFAULT_DOC: Store the journal inside its cache_dir
4000DOC_START
4001 Location for the cache "swap.state" file. This index file holds
4002 the metadata of objects saved on disk. It is used to rebuild
4003 the cache during startup. Normally this file resides in each
4004 'cache_dir' directory, but you may specify an alternate
4005 pathname here. Note you must give a full filename, not just
4006 a directory. Since this is the index for the whole object
4007 list you CANNOT periodically rotate it!
4008
4009 If %s can be used in the file name it will be replaced with a
4010 a representation of the cache_dir name where each / is replaced
4011 with '.'. This is needed to allow adding/removing cache_dir
4012 lines when cache_swap_log is being used.
4013
4014 If have more than one 'cache_dir', and %s is not used in the name
4015 these swap logs will have names such as:
4016
4017 cache_swap_log.00
4018 cache_swap_log.01
4019 cache_swap_log.02
4020
4021 The numbered extension (which is added automatically)
4022 corresponds to the order of the 'cache_dir' lines in this
4023 configuration file. If you change the order of the 'cache_dir'
4024 lines in this file, these index files will NOT correspond to
4025 the correct 'cache_dir' entry (unless you manually rename
4026 them). We recommend you do NOT use this option. It is
4027 better to keep these index files in each 'cache_dir' directory.
4028DOC_END
4029
4030NAME: logfile_rotate
4031TYPE: int
4032DEFAULT: 10
4033LOC: Config.Log.rotateNumber
4034DOC_START
4035 Specifies the number of logfile rotations to make when you
4036 type 'squid -k rotate'. The default is 10, which will rotate
4037 with extensions 0 through 9. Setting logfile_rotate to 0 will
4038 disable the file name rotation, but the logfiles are still closed
4039 and re-opened. This will enable you to rename the logfiles
4040 yourself just before sending the rotate signal.
4041
4042 Note, the 'squid -k rotate' command normally sends a USR1
4043 signal to the running squid process. In certain situations
4044 (e.g. on Linux with Async I/O), USR1 is used for other
4045 purposes, so -k rotate uses another signal. It is best to get
4046 in the habit of using 'squid -k rotate' instead of 'kill -USR1
4047 <pid>'.
4048
4049 Note, from Squid-3.1 this option is only a default for cache.log,
4050 that log can be rotated separately by using debug_options.
4051DOC_END
4052
4053NAME: emulate_httpd_log
4054TYPE: obsolete
4055DOC_START
4056 Replace this with an access_log directive using the format 'common' or 'combined'.
4057DOC_END
4058
4059NAME: log_ip_on_direct
4060TYPE: obsolete
4061DOC_START
4062 Remove this option from your config. To log server or peer names use %<A in the log format.
4063DOC_END
4064
4065NAME: mime_table
4066TYPE: string
4067DEFAULT: @DEFAULT_MIME_TABLE@
4068LOC: Config.mimeTablePathname
4069DOC_START
4070 Path to Squid's icon configuration file.
4071
4072 You shouldn't need to change this, but the default file contains
4073 examples and formatting information if you do.
4074DOC_END
4075
4076NAME: log_mime_hdrs
4077COMMENT: on|off
4078TYPE: onoff
4079LOC: Config.onoff.log_mime_hdrs
4080DEFAULT: off
4081DOC_START
4082 The Cache can record both the request and the response MIME
4083 headers for each HTTP transaction. The headers are encoded
4084 safely and will appear as two bracketed fields at the end of
4085 the access log (for either the native or httpd-emulated log
4086 formats). To enable this logging set log_mime_hdrs to 'on'.
4087DOC_END
4088
4089NAME: useragent_log
4090TYPE: obsolete
4091DOC_START
4092 Replace this with an access_log directive using the format 'useragent'.
4093DOC_END
4094
4095NAME: referer_log referrer_log
4096TYPE: obsolete
4097DOC_START
4098 Replace this with an access_log directive using the format 'referrer'.
4099DOC_END
4100
4101NAME: pid_filename
4102TYPE: string
4103DEFAULT: @DEFAULT_PID_FILE@
4104LOC: Config.pidFilename
4105DOC_START
4106 A filename to write the process-id to. To disable, enter "none".
4107DOC_END
4108
4109NAME: log_fqdn
4110TYPE: obsolete
4111DOC_START
4112 Remove this option from your config. To log FQDN use %>A in the log format.
4113DOC_END
4114
4115NAME: client_netmask
4116TYPE: address
4117LOC: Config.Addrs.client_netmask
4118DEFAULT: no_addr
4119DEFAULT_DOC: Log full client IP address
4120DOC_START
4121 A netmask for client addresses in logfiles and cachemgr output.
4122 Change this to protect the privacy of your cache clients.
4123 A netmask of 255.255.255.0 will log all IP's in that range with
4124 the last digit set to '0'.
4125DOC_END
4126
4127NAME: forward_log
4128TYPE: obsolete
4129DOC_START
4130 Use a regular access.log with ACL limiting it to MISS events.
4131DOC_END
4132
4133NAME: strip_query_terms
4134TYPE: onoff
4135LOC: Config.onoff.strip_query_terms
4136DEFAULT: on
4137DOC_START
4138 By default, Squid strips query terms from requested URLs before
4139 logging. This protects your user's privacy and reduces log size.
4140
4141 When investigating HIT/MISS or other caching behaviour you
4142 will need to disable this to see the full URL used by Squid.
4143DOC_END
4144
4145NAME: buffered_logs
4146COMMENT: on|off
4147TYPE: onoff
4148DEFAULT: off
4149LOC: Config.onoff.buffered_logs
4150DOC_START
4151 Whether to write/send access_log records ASAP or accumulate them and
4152 then write/send them in larger chunks. Buffering may improve
4153 performance because it decreases the number of I/Os. However,
4154 buffering increases the delay before log records become available to
4155 the final recipient (e.g., a disk file or logging daemon) and,
4156 hence, increases the risk of log records loss.
4157
4158 Note that even when buffered_logs are off, Squid may have to buffer
4159 records if it cannot write/send them immediately due to pending I/Os
4160 (e.g., the I/O writing the previous log record) or connectivity loss.
4161
4162 Currently honored by 'daemon' access_log module only.
4163DOC_END
4164
4165NAME: netdb_filename
4166TYPE: string
4167DEFAULT: stdio:@DEFAULT_NETDB_FILE@
4168LOC: Config.netdbFilename
4169IFDEF: USE_ICMP
4170DOC_START
4171 Where Squid stores it's netdb journal.
4172 When enabled this journal preserves netdb state between restarts.
4173
4174 To disable, enter "none".
4175DOC_END
4176
4177COMMENT_START
4178 OPTIONS FOR TROUBLESHOOTING
4179 -----------------------------------------------------------------------------
4180COMMENT_END
4181
4182NAME: cache_log
4183TYPE: string
4184DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
4185LOC: Debug::cache_log
4186DOC_START
4187 Squid administrative logging file.
4188
4189 This is where general information about Squid behavior goes. You can
4190 increase the amount of data logged to this file and how often it is
4191 rotated with "debug_options"
4192DOC_END
4193
4194NAME: debug_options
4195TYPE: debug_options
4196DEFAULT: ALL,1
4197DEFAULT_DOC: Log all critical and important messages.
4198LOC: Debug::debugOptions
4199DOC_START
4200 Logging options are set as section,level where each source file
4201 is assigned a unique section. Lower levels result in less
4202 output, Full debugging (level 9) can result in a very large
4203 log file, so be careful.
4204
4205 The magic word "ALL" sets debugging levels for all sections.
4206 The default is to run with "ALL,1" to record important warnings.
4207
4208 The rotate=N option can be used to keep more or less of these logs
4209 than would otherwise be kept by logfile_rotate.
4210 For most uses a single log should be enough to monitor current
4211 events affecting Squid.
4212DOC_END
4213
4214NAME: coredump_dir
4215TYPE: string
4216LOC: Config.coredump_dir
4217DEFAULT_IF_NONE: none
4218DEFAULT_DOC: Use the directory from where Squid was started.
4219DOC_START
4220 By default Squid leaves core files in the directory from where
4221 it was started. If you set 'coredump_dir' to a directory
4222 that exists, Squid will chdir() to that directory at startup
4223 and coredump files will be left there.
4224
4225NOCOMMENT_START
4226
4227# Leave coredumps in the first cache dir
4228coredump_dir @DEFAULT_SWAP_DIR@
4229NOCOMMENT_END
4230DOC_END
4231
4232
4233COMMENT_START
4234 OPTIONS FOR FTP GATEWAYING
4235 -----------------------------------------------------------------------------
4236COMMENT_END
4237
4238NAME: ftp_user
4239TYPE: string
4240DEFAULT: Squid@
4241LOC: Config.Ftp.anon_user
4242DOC_START
4243 If you want the anonymous login password to be more informative
4244 (and enable the use of picky FTP servers), set this to something
4245 reasonable for your domain, like wwwuser@somewhere.net
4246
4247 The reason why this is domainless by default is the
4248 request can be made on the behalf of a user in any domain,
4249 depending on how the cache is used.
4250 Some FTP server also validate the email address is valid
4251 (for example perl.com).
4252DOC_END
4253
4254NAME: ftp_passive
4255TYPE: onoff
4256DEFAULT: on
4257LOC: Config.Ftp.passive
4258DOC_START
4259 If your firewall does not allow Squid to use passive
4260 connections, turn off this option.
4261
4262 Use of ftp_epsv_all option requires this to be ON.
4263DOC_END
4264
4265NAME: ftp_epsv_all
4266TYPE: onoff
4267DEFAULT: off
4268LOC: Config.Ftp.epsv_all
4269DOC_START
4270 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4271
4272 NATs may be able to put the connection on a "fast path" through the
4273 translator, as the EPRT command will never be used and therefore,
4274 translation of the data portion of the segments will never be needed.
4275
4276 When a client only expects to do two-way FTP transfers this may be
4277 useful.
4278 If squid finds that it must do a three-way FTP transfer after issuing
4279 an EPSV ALL command, the FTP session will fail.
4280
4281 If you have any doubts about this option do not use it.
4282 Squid will nicely attempt all other connection methods.
4283
4284 Requires ftp_passive to be ON (default) for any effect.
4285DOC_END
4286
4287NAME: ftp_epsv
4288TYPE: onoff
4289DEFAULT: on
4290LOC: Config.Ftp.epsv
4291DOC_START
4292 FTP Protocol extensions permit the use of a special "EPSV" command.
4293
4294 NATs may be able to put the connection on a "fast path" through the
4295 translator using EPSV, as the EPRT command will never be used
4296 and therefore, translation of the data portion of the segments
4297 will never be needed.
4298
4299 Turning this OFF will prevent EPSV being attempted.
4300 WARNING: Doing so will convert Squid back to the old behavior with all
4301 the related problems with external NAT devices/layers.
4302
4303 Requires ftp_passive to be ON (default) for any effect.
4304DOC_END
4305
4306NAME: ftp_eprt
4307TYPE: onoff
4308DEFAULT: on
4309LOC: Config.Ftp.eprt
4310DOC_START
4311 FTP Protocol extensions permit the use of a special "EPRT" command.
4312
4313 This extension provides a protocol neutral alternative to the
4314 IPv4-only PORT command. When supported it enables active FTP data
4315 channels over IPv6 and efficient NAT handling.
4316
4317 Turning this OFF will prevent EPRT being attempted and will skip
4318 straight to using PORT for IPv4 servers.
4319
4320 Some devices are known to not handle this extension correctly and
4321 may result in crashes. Devices which suport EPRT enough to fail
4322 cleanly will result in Squid attempting PORT anyway. This directive
4323 should only be disabled when EPRT results in device failures.
4324
4325 WARNING: Doing so will convert Squid back to the old behavior with all
4326 the related problems with external NAT devices/layers and IPv4-only FTP.
4327DOC_END
4328
4329NAME: ftp_sanitycheck
4330TYPE: onoff
4331DEFAULT: on
4332LOC: Config.Ftp.sanitycheck
4333DOC_START
4334 For security and data integrity reasons Squid by default performs
4335 sanity checks of the addresses of FTP data connections ensure the
4336 data connection is to the requested server. If you need to allow
4337 FTP connections to servers using another IP address for the data
4338 connection turn this off.
4339DOC_END
4340
4341NAME: ftp_telnet_protocol
4342TYPE: onoff
4343DEFAULT: on
4344LOC: Config.Ftp.telnet
4345DOC_START
4346 The FTP protocol is officially defined to use the telnet protocol
4347 as transport channel for the control connection. However, many
4348 implementations are broken and does not respect this aspect of
4349 the FTP protocol.
4350
4351 If you have trouble accessing files with ASCII code 255 in the
4352 path or similar problems involving this ASCII code you can
4353 try setting this directive to off. If that helps, report to the
4354 operator of the FTP server in question that their FTP server
4355 is broken and does not follow the FTP standard.
4356DOC_END
4357
4358COMMENT_START
4359 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4360 -----------------------------------------------------------------------------
4361COMMENT_END
4362
4363NAME: diskd_program
4364TYPE: string
4365DEFAULT: @DEFAULT_DISKD@
4366LOC: Config.Program.diskd
4367DOC_START
4368 Specify the location of the diskd executable.
4369 Note this is only useful if you have compiled in
4370 diskd as one of the store io modules.
4371DOC_END
4372
4373NAME: unlinkd_program
4374IFDEF: USE_UNLINKD
4375TYPE: string
4376DEFAULT: @DEFAULT_UNLINKD@
4377LOC: Config.Program.unlinkd
4378DOC_START
4379 Specify the location of the executable for file deletion process.
4380DOC_END
4381
4382NAME: pinger_program
4383TYPE: string
4384DEFAULT: @DEFAULT_PINGER@
4385LOC: Config.pinger.program
4386IFDEF: USE_ICMP
4387DOC_START
4388 Specify the location of the executable for the pinger process.
4389DOC_END
4390
4391NAME: pinger_enable
4392TYPE: onoff
4393DEFAULT: on
4394LOC: Config.pinger.enable
4395IFDEF: USE_ICMP
4396DOC_START
4397 Control whether the pinger is active at run-time.
4398 Enables turning ICMP pinger on and off with a simple
4399 squid -k reconfigure.
4400DOC_END
4401
4402
4403COMMENT_START
4404 OPTIONS FOR URL REWRITING
4405 -----------------------------------------------------------------------------
4406COMMENT_END
4407
4408NAME: url_rewrite_program redirect_program
4409TYPE: wordlist
4410LOC: Config.Program.redirect
4411DEFAULT: none
4412DOC_START
4413 Specify the location of the executable URL rewriter to use.
4414 Since they can perform almost any function there isn't one included.
4415
4416 For each requested URL, the rewriter will receive on line with the format
4417
4418 [channel-ID <SP>] URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kv-pairs]<NL>
4419
4420
4421 After processing the request the helper must reply using the following format:
4422
4423 [channel-ID <SP>] result [<SP> kv-pairs]
4424
4425 The result code can be:
4426
4427 OK status=30N url="..."
4428 Redirect the URL to the one supplied in 'url='.
4429 'status=' is optional and contains the status code to send
4430 the client in Squids HTTP response. It must be one of the
4431 HTTP redirect status codes: 301, 302, 303, 307, 308.
4432 When no status is given Squid will use 302.
4433
4434 OK rewrite-url="..."
4435 Rewrite the URL to the one supplied in 'rewrite-url='.
4436 The new URL is fetched directly by Squid and returned to
4437 the client as the response to its request.
4438
4439 ERR
4440 Do not change the URL.
4441
4442 BH
4443 An internal error occurred in the helper, preventing
4444 a result being identified.
4445
4446
4447 In the future, the interface protocol will be extended with
4448 key=value pairs ("kv-pairs" shown above). Helper programs
4449 should be prepared to receive and possibly ignore additional
4450 whitespace-separated tokens on each input line.
4451
4452 When using the concurrency= option the protocol is changed by
4453 introducing a query channel tag in front of the request/response.
4454 The query channel tag is a number between 0 and concurrency-1.
4455 This value must be echoed back unchanged to Squid as the first part
4456 of the response relating to its request.
4457
4458 WARNING: URL re-writing ability should be avoided whenever possible.
4459 Use the URL redirect form of response instead.
4460
4461 Re-write creates a difference in the state held by the client
4462 and server. Possibly causing confusion when the server response
4463 contains snippets of its view state. Embeded URLs, response
4464 and content Location headers, etc. are not re-written by this
4465 interface.
4466
4467 By default, a URL rewriter is not used.
4468DOC_END
4469
4470NAME: url_rewrite_children redirect_children
4471TYPE: HelperChildConfig
4472DEFAULT: 20 startup=0 idle=1 concurrency=0
4473LOC: Config.redirectChildren
4474DOC_START
4475 The maximum number of redirector processes to spawn. If you limit
4476 it too few Squid will have to wait for them to process a backlog of
4477 URLs, slowing it down. If you allow too many they will use RAM
4478 and other system resources noticably.
4479
4480 The startup= and idle= options allow some measure of skew in your
4481 tuning.
4482
4483 startup=
4484
4485 Sets a minimum of how many processes are to be spawned when Squid
4486 starts or reconfigures. When set to zero the first request will
4487 cause spawning of the first child process to handle it.
4488
4489 Starting too few will cause an initial slowdown in traffic as Squid
4490 attempts to simultaneously spawn enough processes to cope.
4491
4492 idle=
4493
4494 Sets a minimum of how many processes Squid is to try and keep available
4495 at all times. When traffic begins to rise above what the existing
4496 processes can handle this many more will be spawned up to the maximum
4497 configured. A minimum setting of 1 is required.
4498
4499 concurrency=
4500
4501 The number of requests each redirector helper can handle in
4502 parallel. Defaults to 0 which indicates the redirector
4503 is a old-style single threaded redirector.
4504
4505 When this directive is set to a value >= 1 then the protocol
4506 used to communicate with the helper is modified to include
4507 an ID in front of the request/response. The ID from the request
4508 must be echoed back with the response to that request.
4509DOC_END
4510
4511NAME: url_rewrite_host_header redirect_rewrites_host_header
4512TYPE: onoff
4513DEFAULT: on
4514LOC: Config.onoff.redir_rewrites_host
4515DOC_START
4516 To preserve same-origin security policies in browsers and
4517 prevent Host: header forgery by redirectors Squid rewrites
4518 any Host: header in redirected requests.
4519
4520 If you are running an accelerator this may not be a wanted
4521 effect of a redirector. This directive enables you disable
4522 Host: alteration in reverse-proxy traffic.
4523
4524 WARNING: Entries are cached on the result of the URL rewriting
4525 process, so be careful if you have domain-virtual hosts.
4526
4527 WARNING: Squid and other software verifies the URL and Host
4528 are matching, so be careful not to relay through other proxies
4529 or inspecting firewalls with this disabled.
4530DOC_END
4531
4532NAME: url_rewrite_access redirector_access
4533TYPE: acl_access
4534DEFAULT: none
4535DEFAULT_DOC: Allow, unless rules exist in squid.conf.
4536LOC: Config.accessList.redirector
4537DOC_START
4538 If defined, this access list specifies which requests are
4539 sent to the redirector processes.
4540
4541 This clause supports both fast and slow acl types.
4542 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4543DOC_END
4544
4545NAME: url_rewrite_bypass redirector_bypass
4546TYPE: onoff
4547LOC: Config.onoff.redirector_bypass
4548DEFAULT: off
4549DOC_START
4550 When this is 'on', a request will not go through the
4551 redirector if all the helpers are busy. If this is 'off'
4552 and the redirector queue grows too large, Squid will exit
4553 with a FATAL error and ask you to increase the number of
4554 redirectors. You should only enable this if the redirectors
4555 are not critical to your caching system. If you use
4556 redirectors for access control, and you enable this option,
4557 users may have access to pages they should not
4558 be allowed to request.
4559DOC_END
4560
4561COMMENT_START
4562 OPTIONS FOR STORE ID
4563 -----------------------------------------------------------------------------
4564COMMENT_END
4565
4566NAME: store_id_program storeurl_rewrite_program
4567TYPE: wordlist
4568LOC: Config.Program.store_id
4569DEFAULT: none
4570DOC_START
4571 Specify the location of the executable StoreID helper to use.
4572 Since they can perform almost any function there isn't one included.
4573
4574 For each requested URL, the helper will receive one line with the format
4575
4576 [channel-ID <SP>] URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kv-pairs]<NL>
4577
4578
4579 After processing the request the helper must reply using the following format:
4580
4581 [channel-ID <SP>] result [<SP> kv-pairs]
4582
4583 The result code can be:
4584
4585 OK store-id="..."
4586 Use the StoreID supplied in 'store-id='.
4587
4588 ERR
4589 The default is to use HTTP request URL as the store ID.
4590
4591 BH
4592 An internal error occured in the helper, preventing
4593 a result being identified.
4594
4595
4596 Helper programs should be prepared to receive and possibly ignore additional
4597 kv-pairs with keys they do not support.
4598
4599 When using the concurrency= option the protocol is changed by
4600 introducing a query channel tag in front of the request/response.
4601 The query channel tag is a number between 0 and concurrency-1.
4602 This value must be echoed back unchanged to Squid as the first part
4603 of the response relating to its request.
4604
4605 NOTE: when using StoreID refresh_pattern will apply to the StoreID
4606 returned from the helper and not the URL.
4607
4608 WARNING: Wrong StoreID value returned by a careless helper may result
4609 in the wrong cached response returned to the user.
4610
4611 By default, a StoreID helper is not used.
4612DOC_END
4613
4614NAME: store_id_children storeurl_rewrite_children
4615TYPE: HelperChildConfig
4616DEFAULT: 20 startup=0 idle=1 concurrency=0
4617LOC: Config.storeIdChildren
4618DOC_START
4619 The maximum number of StoreID helper processes to spawn. If you limit
4620 it too few Squid will have to wait for them to process a backlog of
4621 requests, slowing it down. If you allow too many they will use RAM
4622 and other system resources noticably.
4623
4624 The startup= and idle= options allow some measure of skew in your
4625 tuning.
4626
4627 startup=
4628
4629 Sets a minimum of how many processes are to be spawned when Squid
4630 starts or reconfigures. When set to zero the first request will
4631 cause spawning of the first child process to handle it.
4632
4633 Starting too few will cause an initial slowdown in traffic as Squid
4634 attempts to simultaneously spawn enough processes to cope.
4635
4636 idle=
4637
4638 Sets a minimum of how many processes Squid is to try and keep available
4639 at all times. When traffic begins to rise above what the existing
4640 processes can handle this many more will be spawned up to the maximum
4641 configured. A minimum setting of 1 is required.
4642
4643 concurrency=
4644
4645 The number of requests each storeID helper can handle in
4646 parallel. Defaults to 0 which indicates the helper
4647 is a old-style single threaded program.
4648
4649 When this directive is set to a value >= 1 then the protocol
4650 used to communicate with the helper is modified to include
4651 an ID in front of the request/response. The ID from the request
4652 must be echoed back with the response to that request.
4653DOC_END
4654
4655NAME: store_id_access storeurl_rewrite_access
4656TYPE: acl_access
4657DEFAULT: none
4658DEFAULT_DOC: Allow, unless rules exist in squid.conf.
4659LOC: Config.accessList.store_id
4660DOC_START
4661 If defined, this access list specifies which requests are
4662 sent to the StoreID processes. By default all requests
4663 are sent.
4664
4665 This clause supports both fast and slow acl types.
4666 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4667DOC_END
4668
4669NAME: store_id_bypass storeurl_rewrite_bypass
4670TYPE: onoff
4671LOC: Config.onoff.store_id_bypass
4672DEFAULT: on
4673DOC_START
4674 When this is 'on', a request will not go through the
4675 helper if all helpers are busy. If this is 'off'
4676 and the helper queue grows too large, Squid will exit
4677 with a FATAL error and ask you to increase the number of
4678 helpers. You should only enable this if the helperss
4679 are not critical to your caching system. If you use
4680 helpers for critical caching components, and you enable this
4681 option, users may not get objects from cache.
4682DOC_END
4683
4684COMMENT_START
4685 OPTIONS FOR TUNING THE CACHE
4686 -----------------------------------------------------------------------------
4687COMMENT_END
4688
4689NAME: cache no_cache
4690TYPE: acl_access
4691DEFAULT: none
4692DEFAULT_DOC: Allow caching, unless rules exist in squid.conf.
4693LOC: Config.accessList.noCache
4694DOC_START
4695 A list of ACL elements which, if matched and denied, cause the request to
4696 not be satisfied from the cache and the reply to not be cached.
4697 In other words, use this to force certain objects to never be cached.
4698
4699 You must use the words 'allow' or 'deny' to indicate whether items
4700 matching the ACL should be allowed or denied into the cache.
4701
4702 This clause supports both fast and slow acl types.
4703 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4704DOC_END
4705
4706NAME: max_stale
4707COMMENT: time-units
4708TYPE: time_t
4709LOC: Config.maxStale
4710DEFAULT: 1 week
4711DOC_START
4712 This option puts an upper limit on how stale content Squid
4713 will serve from the cache if cache validation fails.
4714 Can be overriden by the refresh_pattern max-stale option.
4715DOC_END
4716
4717NAME: refresh_pattern
4718TYPE: refreshpattern
4719LOC: Config.Refresh
4720DEFAULT: none
4721DOC_START
4722 usage: refresh_pattern [-i] regex min percent max [options]
4723
4724 By default, regular expressions are CASE-SENSITIVE. To make
4725 them case-insensitive, use the -i option.
4726
4727 'Min' is the time (in minutes) an object without an explicit
4728 expiry time should be considered fresh. The recommended
4729 value is 0, any higher values may cause dynamic applications
4730 to be erroneously cached unless the application designer
4731 has taken the appropriate actions.
4732
4733 'Percent' is a percentage of the objects age (time since last
4734 modification age) an object without explicit expiry time
4735 will be considered fresh.
4736
4737 'Max' is an upper limit on how long objects without an explicit
4738 expiry time will be considered fresh.
4739
4740 options: override-expire
4741 override-lastmod
4742 reload-into-ims
4743 ignore-reload
4744 ignore-no-store
4745 ignore-must-revalidate
4746 ignore-private
4747 ignore-auth
4748 max-stale=NN
4749 refresh-ims
4750 store-stale
4751
4752 override-expire enforces min age even if the server
4753 sent an explicit expiry time (e.g., with the
4754 Expires: header or Cache-Control: max-age). Doing this
4755 VIOLATES the HTTP standard. Enabling this feature
4756 could make you liable for problems which it causes.
4757
4758 Note: override-expire does not enforce staleness - it only extends
4759 freshness / min. If the server returns a Expires time which
4760 is longer than your max time, Squid will still consider
4761 the object fresh for that period of time.
4762
4763 override-lastmod enforces min age even on objects
4764 that were modified recently.
4765
4766 reload-into-ims changes client no-cache or ``reload''
4767 to If-Modified-Since requests. Doing this VIOLATES the
4768 HTTP standard. Enabling this feature could make you
4769 liable for problems which it causes.
4770
4771 ignore-reload ignores a client no-cache or ``reload''
4772 header. Doing this VIOLATES the HTTP standard. Enabling
4773 this feature could make you liable for problems which
4774 it causes.
4775
4776 ignore-no-store ignores any ``Cache-control: no-store''
4777 headers received from a server. Doing this VIOLATES
4778 the HTTP standard. Enabling this feature could make you
4779 liable for problems which it causes.
4780
4781 ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
4782 headers received from a server. Doing this VIOLATES
4783 the HTTP standard. Enabling this feature could make you
4784 liable for problems which it causes.
4785
4786 ignore-private ignores any ``Cache-control: private''
4787 headers received from a server. Doing this VIOLATES
4788 the HTTP standard. Enabling this feature could make you
4789 liable for problems which it causes.
4790
4791 ignore-auth caches responses to requests with authorization,
4792 as if the originserver had sent ``Cache-control: public''
4793 in the response header. Doing this VIOLATES the HTTP standard.
4794 Enabling this feature could make you liable for problems which
4795 it causes.
4796
4797 refresh-ims causes squid to contact the origin server
4798 when a client issues an If-Modified-Since request. This
4799 ensures that the client will receive an updated version
4800 if one is available.
4801
4802 store-stale stores responses even if they don't have explicit
4803 freshness or a validator (i.e., Last-Modified or an ETag)
4804 present, or if they're already stale. By default, Squid will
4805 not cache such responses because they usually can't be
4806 reused. Note that such responses will be stale by default.
4807
4808 max-stale=NN provide a maximum staleness factor. Squid won't
4809 serve objects more stale than this even if it failed to
4810 validate the object. Default: use the max_stale global limit.
4811
4812 Basically a cached object is:
4813
4814 FRESH if expires < now, else STALE
4815 STALE if age > max
4816 FRESH if lm-factor < percent, else STALE
4817 FRESH if age < min
4818 else STALE
4819
4820 The refresh_pattern lines are checked in the order listed here.
4821 The first entry which matches is used. If none of the entries
4822 match the default will be used.
4823
4824 Note, you must uncomment all the default lines if you want
4825 to change one. The default setting is only active if none is
4826 used.
4827
4828NOCOMMENT_START
4829
4830#
4831# Add any of your own refresh_pattern entries above these.
4832#
4833refresh_pattern ^ftp: 1440 20% 10080
4834refresh_pattern ^gopher: 1440 0% 1440
4835refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
4836refresh_pattern . 0 20% 4320
4837NOCOMMENT_END
4838DOC_END
4839
4840NAME: quick_abort_min
4841COMMENT: (KB)
4842TYPE: kb_int64_t
4843DEFAULT: 16 KB
4844LOC: Config.quickAbort.min
4845DOC_NONE
4846
4847NAME: quick_abort_max
4848COMMENT: (KB)
4849TYPE: kb_int64_t
4850DEFAULT: 16 KB
4851LOC: Config.quickAbort.max
4852DOC_NONE
4853
4854NAME: quick_abort_pct
4855COMMENT: (percent)
4856TYPE: int
4857DEFAULT: 95
4858LOC: Config.quickAbort.pct
4859DOC_START
4860 The cache by default continues downloading aborted requests
4861 which are almost completed (less than 16 KB remaining). This
4862 may be undesirable on slow (e.g. SLIP) links and/or very busy
4863 caches. Impatient users may tie up file descriptors and
4864 bandwidth by repeatedly requesting and immediately aborting
4865 downloads.
4866
4867 When the user aborts a request, Squid will check the
4868 quick_abort values to the amount of data transfered until
4869 then.
4870
4871 If the transfer has less than 'quick_abort_min' KB remaining,
4872 it will finish the retrieval.
4873
4874 If the transfer has more than 'quick_abort_max' KB remaining,
4875 it will abort the retrieval.
4876
4877 If more than 'quick_abort_pct' of the transfer has completed,
4878 it will finish the retrieval.
4879
4880 If you do not want any retrieval to continue after the client
4881 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
4882 to '0 KB'.
4883
4884 If you want retrievals to always continue if they are being
4885 cached set 'quick_abort_min' to '-1 KB'.
4886DOC_END
4887
4888NAME: read_ahead_gap
4889COMMENT: buffer-size
4890TYPE: b_int64_t
4891LOC: Config.readAheadGap
4892DEFAULT: 16 KB
4893DOC_START
4894 The amount of data the cache will buffer ahead of what has been
4895 sent to the client when retrieving an object from another server.
4896DOC_END
4897
4898NAME: negative_ttl
4899IFDEF: USE_HTTP_VIOLATIONS
4900COMMENT: time-units
4901TYPE: time_t
4902LOC: Config.negativeTtl
4903DEFAULT: 0 seconds
4904DOC_START
4905 Set the Default Time-to-Live (TTL) for failed requests.
4906 Certain types of failures (such as "connection refused" and
4907 "404 Not Found") are able to be negatively-cached for a short time.
4908 Modern web servers should provide Expires: header, however if they
4909 do not this can provide a minimum TTL.
4910 The default is not to cache errors with unknown expiry details.
4911
4912 Note that this is different from negative caching of DNS lookups.
4913
4914 WARNING: Doing this VIOLATES the HTTP standard. Enabling
4915 this feature could make you liable for problems which it
4916 causes.
4917DOC_END
4918
4919NAME: positive_dns_ttl
4920COMMENT: time-units
4921TYPE: time_t
4922LOC: Config.positiveDnsTtl
4923DEFAULT: 6 hours
4924DOC_START
4925 Upper limit on how long Squid will cache positive DNS responses.
4926 Default is 6 hours (360 minutes). This directive must be set
4927 larger than negative_dns_ttl.
4928DOC_END
4929
4930NAME: negative_dns_ttl
4931COMMENT: time-units
4932TYPE: time_t
4933LOC: Config.negativeDnsTtl
4934DEFAULT: 1 minutes
4935DOC_START
4936 Time-to-Live (TTL) for negative caching of failed DNS lookups.
4937 This also sets the lower cache limit on positive lookups.
4938 Minimum value is 1 second, and it is not recommendable to go
4939 much below 10 seconds.
4940DOC_END
4941
4942NAME: range_offset_limit
4943COMMENT: size [acl acl...]
4944TYPE: acl_b_size_t
4945LOC: Config.rangeOffsetLimit
4946DEFAULT: none
4947DOC_START
4948 usage: (size) [units] [[!]aclname]
4949
4950 Sets an upper limit on how far (number of bytes) into the file
4951 a Range request may be to cause Squid to prefetch the whole file.
4952 If beyond this limit, Squid forwards the Range request as it is and
4953 the result is NOT cached.
4954
4955 This is to stop a far ahead range request (lets say start at 17MB)
4956 from making Squid fetch the whole object up to that point before
4957 sending anything to the client.
4958
4959 Multiple range_offset_limit lines may be specified, and they will
4960 be searched from top to bottom on each request until a match is found.
4961 The first match found will be used. If no line matches a request, the
4962 default limit of 0 bytes will be used.
4963
4964 'size' is the limit specified as a number of units.
4965
4966 'units' specifies whether to use bytes, KB, MB, etc.
4967 If no units are specified bytes are assumed.
4968
4969 A size of 0 causes Squid to never fetch more than the
4970 client requested. (default)
4971
4972 A size of 'none' causes Squid to always fetch the object from the
4973 beginning so it may cache the result. (2.0 style)
4974
4975 'aclname' is the name of a defined ACL.
4976
4977 NP: Using 'none' as the byte value here will override any quick_abort settings
4978 that may otherwise apply to the range request. The range request will
4979 be fully fetched from start to finish regardless of the client
4980 actions. This affects bandwidth usage.
4981DOC_END
4982
4983NAME: minimum_expiry_time
4984COMMENT: (seconds)
4985TYPE: time_t
4986LOC: Config.minimum_expiry_time
4987DEFAULT: 60 seconds
4988DOC_START
4989 The minimum caching time according to (Expires - Date)
4990 headers Squid honors if the object can't be revalidated.
4991 The default is 60 seconds.
4992
4993 In reverse proxy environments it might be desirable to honor
4994 shorter object lifetimes. It is most likely better to make
4995 your server return a meaningful Last-Modified header however.
4996
4997 In ESI environments where page fragments often have short
4998 lifetimes, this will often be best set to 0.
4999DOC_END
5000
5001NAME: store_avg_object_size
5002COMMENT: (bytes)
5003TYPE: b_int64_t
5004DEFAULT: 13 KB
5005LOC: Config.Store.avgObjectSize
5006DOC_START
5007 Average object size, used to estimate number of objects your
5008 cache can hold. The default is 13 KB.
5009
5010 This is used to pre-seed the cache index memory allocation to
5011 reduce expensive reallocate operations while handling clients
5012 traffic. Too-large values may result in memory allocation during
5013 peak traffic, too-small values will result in wasted memory.
5014
5015 Check the cache manager 'info' report metrics for the real
5016 object sizes seen by your Squid before tuning this.
5017DOC_END
5018
5019NAME: store_objects_per_bucket
5020TYPE: int
5021DEFAULT: 20
5022LOC: Config.Store.objectsPerBucket
5023DOC_START
5024 Target number of objects per bucket in the store hash table.
5025 Lowering this value increases the total number of buckets and
5026 also the storage maintenance rate. The default is 20.
5027DOC_END
5028
5029COMMENT_START
5030 HTTP OPTIONS
5031 -----------------------------------------------------------------------------
5032COMMENT_END
5033
5034NAME: request_header_max_size
5035COMMENT: (KB)
5036TYPE: b_size_t
5037DEFAULT: 64 KB
5038LOC: Config.maxRequestHeaderSize
5039DOC_START
5040 This specifies the maximum size for HTTP headers in a request.
5041 Request headers are usually relatively small (about 512 bytes).
5042 Placing a limit on the request header size will catch certain
5043 bugs (for example with persistent connections) and possibly
5044 buffer-overflow or denial-of-service attacks.
5045DOC_END
5046
5047NAME: reply_header_max_size
5048COMMENT: (KB)
5049TYPE: b_size_t
5050DEFAULT: 64 KB
5051LOC: Config.maxReplyHeaderSize
5052DOC_START
5053 This specifies the maximum size for HTTP headers in a reply.
5054 Reply headers are usually relatively small (about 512 bytes).
5055 Placing a limit on the reply header size will catch certain
5056 bugs (for example with persistent connections) and possibly
5057 buffer-overflow or denial-of-service attacks.
5058DOC_END
5059
5060NAME: request_body_max_size
5061COMMENT: (bytes)
5062TYPE: b_int64_t
5063DEFAULT: 0 KB
5064DEFAULT_DOC: No limit.
5065LOC: Config.maxRequestBodySize
5066DOC_START
5067 This specifies the maximum size for an HTTP request body.
5068 In other words, the maximum size of a PUT/POST request.
5069 A user who attempts to send a request with a body larger
5070 than this limit receives an "Invalid Request" error message.
5071 If you set this parameter to a zero (the default), there will
5072 be no limit imposed.
5073
5074 See also client_request_buffer_max_size for an alternative
5075 limitation on client uploads which can be configured.
5076DOC_END
5077
5078NAME: client_request_buffer_max_size
5079COMMENT: (bytes)
5080TYPE: b_size_t
5081DEFAULT: 512 KB
5082LOC: Config.maxRequestBufferSize
5083DOC_START
5084 This specifies the maximum buffer size of a client request.
5085 It prevents squid eating too much memory when somebody uploads
5086 a large file.
5087DOC_END
5088
5089NAME: chunked_request_body_max_size
5090COMMENT: (bytes)
5091TYPE: b_int64_t
5092DEFAULT: 64 KB
5093LOC: Config.maxChunkedRequestBodySize
5094DOC_START
5095 A broken or confused HTTP/1.1 client may send a chunked HTTP
5096 request to Squid. Squid does not have full support for that
5097 feature yet. To cope with such requests, Squid buffers the
5098 entire request and then dechunks request body to create a
5099 plain HTTP/1.0 request with a known content length. The plain
5100 request is then used by the rest of Squid code as usual.
5101
5102 The option value specifies the maximum size of the buffer used
5103 to hold the request before the conversion. If the chunked
5104 request size exceeds the specified limit, the conversion
5105 fails, and the client receives an "unsupported request" error,
5106 as if dechunking was disabled.
5107
5108 Dechunking is enabled by default. To disable conversion of
5109 chunked requests, set the maximum to zero.
5110
5111 Request dechunking feature and this option in particular are a
5112 temporary hack. When chunking requests and responses are fully
5113 supported, there will be no need to buffer a chunked request.
5114DOC_END
5115
5116NAME: broken_posts
5117IFDEF: USE_HTTP_VIOLATIONS
5118TYPE: acl_access
5119DEFAULT: none
5120DEFAULT_DOC: Obey RFC 2616.
5121LOC: Config.accessList.brokenPosts
5122DOC_START
5123 A list of ACL elements which, if matched, causes Squid to send
5124 an extra CRLF pair after the body of a PUT/POST request.
5125
5126 Some HTTP servers has broken implementations of PUT/POST,
5127 and rely on an extra CRLF pair sent by some WWW clients.
5128
5129 Quote from RFC2616 section 4.1 on this matter:
5130
5131 Note: certain buggy HTTP/1.0 client implementations generate an
5132 extra CRLF's after a POST request. To restate what is explicitly
5133 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5134 a request with an extra CRLF.
5135
5136 This clause only supports fast acl types.
5137 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5138
5139Example:
5140 acl buggy_server url_regex ^http://....
5141 broken_posts allow buggy_server
5142DOC_END
5143
5144NAME: adaptation_uses_indirect_client icap_uses_indirect_client
5145COMMENT: on|off
5146TYPE: onoff
5147IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
5148DEFAULT: on
5149LOC: Adaptation::Config::use_indirect_client
5150DOC_START
5151 Controls whether the indirect client IP address (instead of the direct
5152 client IP address) is passed to adaptation services.
5153
5154 See also: follow_x_forwarded_for adaptation_send_client_ip
5155DOC_END
5156
5157NAME: via
5158IFDEF: USE_HTTP_VIOLATIONS
5159COMMENT: on|off
5160TYPE: onoff
5161DEFAULT: on
5162LOC: Config.onoff.via
5163DOC_START
5164 If set (default), Squid will include a Via header in requests and
5165 replies as required by RFC2616.
5166DOC_END
5167
5168NAME: ie_refresh
5169COMMENT: on|off
5170TYPE: onoff
5171LOC: Config.onoff.ie_refresh
5172DEFAULT: off
5173DOC_START
5174 Microsoft Internet Explorer up until version 5.5 Service
5175 Pack 1 has an issue with transparent proxies, wherein it
5176 is impossible to force a refresh. Turning this on provides
5177 a partial fix to the problem, by causing all IMS-REFRESH
5178 requests from older IE versions to check the origin server
5179 for fresh content. This reduces hit ratio by some amount
5180 (~10% in my experience), but allows users to actually get
5181 fresh content when they want it. Note because Squid
5182 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
5183 of 5.5 is unchanged from old versions of Squid (i.e. a
5184 forced refresh is impossible). Newer versions of IE will,
5185 hopefully, continue to have the new behavior and will be
5186 handled based on that assumption. This option defaults to
5187 the old Squid behavior, which is better for hit ratios but
5188 worse for clients using IE, if they need to be able to
5189 force fresh content.
5190DOC_END
5191
5192NAME: vary_ignore_expire
5193COMMENT: on|off
5194TYPE: onoff
5195LOC: Config.onoff.vary_ignore_expire
5196DEFAULT: off
5197DOC_START
5198 Many HTTP servers supporting Vary gives such objects
5199 immediate expiry time with no cache-control header
5200 when requested by a HTTP/1.0 client. This option
5201 enables Squid to ignore such expiry times until
5202 HTTP/1.1 is fully implemented.
5203
5204 WARNING: If turned on this may eventually cause some
5205 varying objects not intended for caching to get cached.
5206DOC_END
5207
5208NAME: request_entities
5209TYPE: onoff
5210LOC: Config.onoff.request_entities
5211DEFAULT: off
5212DOC_START
5213 Squid defaults to deny GET and HEAD requests with request entities,
5214 as the meaning of such requests are undefined in the HTTP standard
5215 even if not explicitly forbidden.
5216
5217 Set this directive to on if you have clients which insists
5218 on sending request entities in GET or HEAD requests. But be warned
5219 that there is server software (both proxies and web servers) which
5220 can fail to properly process this kind of request which may make you
5221 vulnerable to cache pollution attacks if enabled.
5222DOC_END
5223
5224NAME: request_header_access
5225IFDEF: USE_HTTP_VIOLATIONS
5226TYPE: http_header_access
5227LOC: Config.request_header_access
5228DEFAULT: none
5229DEFAULT_DOC: No limits.
5230DOC_START
5231 Usage: request_header_access header_name allow|deny [!]aclname ...
5232
5233 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5234 this feature could make you liable for problems which it
5235 causes.
5236
5237 This option replaces the old 'anonymize_headers' and the
5238 older 'http_anonymizer' option with something that is much
5239 more configurable. A list of ACLs for each header name allows
5240 removal of specific header fields under specific conditions.
5241
5242 This option only applies to outgoing HTTP request headers (i.e.,
5243 headers sent by Squid to the next HTTP hop such as a cache peer
5244 or an origin server). The option has no effect during cache hit
5245 detection. The equivalent adaptation vectoring point in ICAP
5246 terminology is post-cache REQMOD.
5247
5248 The option is applied to individual outgoing request header
5249 fields. For each request header field F, Squid uses the first
5250 qualifying sets of request_header_access rules:
5251
5252 1. Rules with header_name equal to F's name.
5253 2. Rules with header_name 'Other', provided F's name is not
5254 on the hard-coded list of commonly used HTTP header names.
5255 3. Rules with header_name 'All'.
5256
5257 Within that qualifying rule set, rule ACLs are checked as usual.
5258 If ACLs of an "allow" rule match, the header field is allowed to
5259 go through as is. If ACLs of a "deny" rule match, the header is
5260 removed and request_header_replace is then checked to identify
5261 if the removed header has a replacement. If no rules within the
5262 set have matching ACLs, the header field is left as is.
5263
5264 For example, to achieve the same behavior as the old
5265 'http_anonymizer standard' option, you should use:
5266
5267 request_header_access From deny all
5268 request_header_access Referer deny all
5269 request_header_access User-Agent deny all
5270
5271 Or, to reproduce the old 'http_anonymizer paranoid' feature
5272 you should use:
5273
5274 request_header_access Authorization allow all
5275 request_header_access Proxy-Authorization allow all
5276 request_header_access Cache-Control allow all
5277 request_header_access Content-Length allow all
5278 request_header_access Content-Type allow all
5279 request_header_access Date allow all
5280 request_header_access Host allow all
5281 request_header_access If-Modified-Since allow all
5282 request_header_access Pragma allow all
5283 request_header_access Accept allow all
5284 request_header_access Accept-Charset allow all
5285 request_header_access Accept-Encoding allow all
5286 request_header_access Accept-Language allow all
5287 request_header_access Connection allow all
5288 request_header_access All deny all
5289
5290 HTTP reply headers are controlled with the reply_header_access directive.
5291
5292 By default, all headers are allowed (no anonymizing is performed).
5293DOC_END
5294
5295NAME: reply_header_access
5296IFDEF: USE_HTTP_VIOLATIONS
5297TYPE: http_header_access
5298LOC: Config.reply_header_access
5299DEFAULT: none
5300DEFAULT_DOC: No limits.
5301DOC_START
5302 Usage: reply_header_access header_name allow|deny [!]aclname ...
5303
5304 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5305 this feature could make you liable for problems which it
5306 causes.
5307
5308 This option only applies to reply headers, i.e., from the
5309 server to the client.
5310
5311 This is the same as request_header_access, but in the other
5312 direction. Please see request_header_access for detailed
5313 documentation.
5314
5315 For example, to achieve the same behavior as the old
5316 'http_anonymizer standard' option, you should use:
5317
5318 reply_header_access Server deny all
5319 reply_header_access WWW-Authenticate deny all
5320 reply_header_access Link deny all
5321
5322 Or, to reproduce the old 'http_anonymizer paranoid' feature
5323 you should use:
5324
5325 reply_header_access Allow allow all
5326 reply_header_access WWW-Authenticate allow all
5327 reply_header_access Proxy-Authenticate allow all
5328 reply_header_access Cache-Control allow all
5329 reply_header_access Content-Encoding allow all
5330 reply_header_access Content-Length allow all
5331 reply_header_access Content-Type allow all
5332 reply_header_access Date allow all
5333 reply_header_access Expires allow all
5334 reply_header_access Last-Modified allow all
5335 reply_header_access Location allow all
5336 reply_header_access Pragma allow all
5337 reply_header_access Content-Language allow all
5338 reply_header_access Retry-After allow all
5339 reply_header_access Title allow all
5340 reply_header_access Content-Disposition allow all
5341 reply_header_access Connection allow all
5342 reply_header_access All deny all
5343
5344 HTTP request headers are controlled with the request_header_access directive.
5345
5346 By default, all headers are allowed (no anonymizing is
5347 performed).
5348DOC_END
5349
5350NAME: request_header_replace header_replace
5351IFDEF: USE_HTTP_VIOLATIONS
5352TYPE: http_header_replace
5353LOC: Config.request_header_access
5354DEFAULT: none
5355DOC_START
5356 Usage: request_header_replace header_name message
5357 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5358
5359 This option allows you to change the contents of headers
5360 denied with request_header_access above, by replacing them
5361 with some fixed string.
5362
5363 This only applies to request headers, not reply headers.
5364
5365 By default, headers are removed if denied.
5366DOC_END
5367
5368NAME: reply_header_replace
5369IFDEF: USE_HTTP_VIOLATIONS
5370TYPE: http_header_replace
5371LOC: Config.reply_header_access
5372DEFAULT: none
5373DOC_START
5374 Usage: reply_header_replace header_name message
5375 Example: reply_header_replace Server Foo/1.0
5376
5377 This option allows you to change the contents of headers
5378 denied with reply_header_access above, by replacing them
5379 with some fixed string.
5380
5381 This only applies to reply headers, not request headers.
5382
5383 By default, headers are removed if denied.
5384DOC_END
5385
5386NAME: request_header_add
5387TYPE: HeaderWithAclList
5388LOC: Config.request_header_add
5389DEFAULT: none
5390DOC_START
5391 Usage: request_header_add field-name field-value acl1 [acl2] ...
5392 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5393
5394 This option adds header fields to outgoing HTTP requests (i.e.,
5395 request headers sent by Squid to the next HTTP hop such as a
5396 cache peer or an origin server). The option has no effect during
5397 cache hit detection. The equivalent adaptation vectoring point
5398 in ICAP terminology is post-cache REQMOD.
5399
5400 Field-name is a token specifying an HTTP header name. If a
5401 standard HTTP header name is used, Squid does not check whether
5402 the new header conflicts with any existing headers or violates
5403 HTTP rules. If the request to be modified already contains a
5404 field with the same name, the old field is preserved but the
5405 header field values are not merged.
5406
5407 Field-value is either a token or a quoted string. If quoted
5408 string format is used, then the surrounding quotes are removed
5409 while escape sequences and %macros are processed.
5410
5411 In theory, all of the logformat codes can be used as %macros.
5412 However, unlike logging (which happens at the very end of
5413 transaction lifetime), the transaction may not yet have enough
5414 information to expand a macro when the new header value is needed.
5415 And some information may already be available to Squid but not yet
5416 committed where the macro expansion code can access it (report
5417 such instances!). The macro will be expanded into a single dash
5418 ('-') in such cases. Not all macros have been tested.
5419
5420 One or more Squid ACLs may be specified to restrict header
5421 injection to matching requests. As always in squid.conf, all
5422 ACLs in an option ACL list must be satisfied for the insertion
5423 to happen. The request_header_add option supports fast ACLs
5424 only.
5425DOC_END
5426
5427NAME: note
5428TYPE: note
5429LOC: Config.notes
5430DEFAULT: none
5431DOC_START
5432 This option used to log custom information about the master
5433 transaction. For example, an admin may configure Squid to log
5434 which "user group" the transaction belongs to, where "user group"
5435 will be determined based on a set of ACLs and not [just]
5436 authentication information.
5437 Values of key/value pairs can be logged using %{key}note macros:
5438
5439 note key value acl ...
5440 logformat myFormat ... %{key}note ...
5441DOC_END
5442
5443NAME: relaxed_header_parser
5444COMMENT: on|off|warn
5445TYPE: tristate
5446LOC: Config.onoff.relaxed_header_parser
5447DEFAULT: on
5448DOC_START
5449 In the default "on" setting Squid accepts certain forms
5450 of non-compliant HTTP messages where it is unambiguous
5451 what the sending application intended even if the message
5452 is not correctly formatted. The messages is then normalized
5453 to the correct form when forwarded by Squid.
5454
5455 If set to "warn" then a warning will be emitted in cache.log
5456 each time such HTTP error is encountered.
5457
5458 If set to "off" then such HTTP errors will cause the request
5459 or response to be rejected.
5460DOC_END
5461
5462COMMENT_START
5463 TIMEOUTS
5464 -----------------------------------------------------------------------------
5465COMMENT_END
5466
5467NAME: forward_timeout
5468COMMENT: time-units
5469TYPE: time_t
5470LOC: Config.Timeout.forward
5471DEFAULT: 4 minutes
5472DOC_START
5473 This parameter specifies how long Squid should at most attempt in
5474 finding a forwarding path for the request before giving up.
5475DOC_END
5476
5477NAME: connect_timeout
5478COMMENT: time-units
5479TYPE: time_t
5480LOC: Config.Timeout.connect
5481DEFAULT: 1 minute
5482DOC_START
5483 This parameter specifies how long to wait for the TCP connect to
5484 the requested server or peer to complete before Squid should
5485 attempt to find another path where to forward the request.
5486DOC_END
5487
5488NAME: peer_connect_timeout
5489COMMENT: time-units
5490TYPE: time_t
5491LOC: Config.Timeout.peer_connect
5492DEFAULT: 30 seconds
5493DOC_START
5494 This parameter specifies how long to wait for a pending TCP
5495 connection to a peer cache. The default is 30 seconds. You
5496 may also set different timeout values for individual neighbors
5497 with the 'connect-timeout' option on a 'cache_peer' line.
5498DOC_END
5499
5500NAME: read_timeout
5501COMMENT: time-units
5502TYPE: time_t
5503LOC: Config.Timeout.read
5504DEFAULT: 15 minutes
5505DOC_START
5506 The read_timeout is applied on server-side connections. After
5507 each successful read(), the timeout will be extended by this
5508 amount. If no data is read again after this amount of time,
5509 the request is aborted and logged with ERR_READ_TIMEOUT. The
5510 default is 15 minutes.
5511DOC_END
5512
5513NAME: write_timeout
5514COMMENT: time-units
5515TYPE: time_t
5516LOC: Config.Timeout.write
5517DEFAULT: 15 minutes
5518DOC_START
5519 This timeout is tracked for all connections that have data
5520 available for writing and are waiting for the socket to become
5521 ready. After each successful write, the timeout is extended by
5522 the configured amount. If Squid has data to write but the
5523 connection is not ready for the configured duration, the
5524 transaction associated with the connection is terminated. The
5525 default is 15 minutes.
5526DOC_END
5527
5528NAME: request_timeout
5529TYPE: time_t
5530LOC: Config.Timeout.request
5531DEFAULT: 5 minutes
5532DOC_START
5533 How long to wait for complete HTTP request headers after initial
5534 connection establishment.
5535DOC_END
5536
5537NAME: client_idle_pconn_timeout persistent_request_timeout
5538TYPE: time_t
5539LOC: Config.Timeout.clientIdlePconn
5540DEFAULT: 2 minutes
5541DOC_START
5542 How long to wait for the next HTTP request on a persistent
5543 client connection after the previous request completes.
5544DOC_END
5545
5546NAME: client_lifetime
5547COMMENT: time-units
5548TYPE: time_t
5549LOC: Config.Timeout.lifetime
5550DEFAULT: 1 day
5551DOC_START
5552 The maximum amount of time a client (browser) is allowed to
5553 remain connected to the cache process. This protects the Cache
5554 from having a lot of sockets (and hence file descriptors) tied up
5555 in a CLOSE_WAIT state from remote clients that go away without
5556 properly shutting down (either because of a network failure or
5557 because of a poor client implementation). The default is one
5558 day, 1440 minutes.
5559
5560 NOTE: The default value is intended to be much larger than any
5561 client would ever need to be connected to your cache. You
5562 should probably change client_lifetime only as a last resort.
5563 If you seem to have many client connections tying up
5564 filedescriptors, we recommend first tuning the read_timeout,
5565 request_timeout, persistent_request_timeout and quick_abort values.
5566DOC_END
5567
5568NAME: half_closed_clients
5569TYPE: onoff
5570LOC: Config.onoff.half_closed_clients
5571DEFAULT: off
5572DOC_START
5573 Some clients may shutdown the sending side of their TCP
5574 connections, while leaving their receiving sides open. Sometimes,
5575 Squid can not tell the difference between a half-closed and a
5576 fully-closed TCP connection.
5577
5578 By default, Squid will immediately close client connections when
5579 read(2) returns "no more data to read."
5580
5581 Change this option to 'on' and Squid will keep open connections
5582 until a read(2) or write(2) on the socket returns an error.
5583 This may show some benefits for reverse proxies. But if not
5584 it is recommended to leave OFF.
5585DOC_END
5586
5587NAME: server_idle_pconn_timeout pconn_timeout
5588TYPE: time_t
5589LOC: Config.Timeout.serverIdlePconn
5590DEFAULT: 1 minute
5591DOC_START
5592 Timeout for idle persistent connections to servers and other
5593 proxies.
5594DOC_END
5595
5596NAME: ident_timeout
5597TYPE: time_t
5598IFDEF: USE_IDENT
5599LOC: Ident::TheConfig.timeout
5600DEFAULT: 10 seconds
5601DOC_START
5602 Maximum time to wait for IDENT lookups to complete.
5603
5604 If this is too high, and you enabled IDENT lookups from untrusted
5605 users, you might be susceptible to denial-of-service by having
5606 many ident requests going at once.
5607DOC_END
5608
5609NAME: shutdown_lifetime
5610COMMENT: time-units
5611TYPE: time_t
5612LOC: Config.shutdownLifetime
5613DEFAULT: 30 seconds
5614DOC_START
5615 When SIGTERM or SIGHUP is received, the cache is put into
5616 "shutdown pending" mode until all active sockets are closed.
5617 This value is the lifetime to set for all open descriptors
5618 during shutdown mode. Any active clients after this many
5619 seconds will receive a 'timeout' message.
5620DOC_END
5621
5622COMMENT_START
5623 ADMINISTRATIVE PARAMETERS
5624 -----------------------------------------------------------------------------
5625COMMENT_END
5626
5627NAME: cache_mgr
5628TYPE: string
5629DEFAULT: webmaster
5630LOC: Config.adminEmail
5631DOC_START
5632 Email-address of local cache manager who will receive
5633 mail if the cache dies. The default is "webmaster".
5634DOC_END
5635
5636NAME: mail_from
5637TYPE: string
5638DEFAULT: none
5639LOC: Config.EmailFrom
5640DOC_START
5641 From: email-address for mail sent when the cache dies.
5642 The default is to use 'squid@unique_hostname'.
5643
5644 See also: unique_hostname directive.
5645DOC_END
5646
5647NAME: mail_program
5648TYPE: eol
5649DEFAULT: mail
5650LOC: Config.EmailProgram
5651DOC_START
5652 Email program used to send mail if the cache dies.
5653 The default is "mail". The specified program must comply
5654 with the standard Unix mail syntax:
5655 mail-program recipient < mailfile
5656
5657 Optional command line options can be specified.
5658DOC_END
5659
5660NAME: cache_effective_user
5661TYPE: string
5662DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
5663LOC: Config.effectiveUser
5664DOC_START
5665 If you start Squid as root, it will change its effective/real
5666 UID/GID to the user specified below. The default is to change
5667 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
5668 see also; cache_effective_group
5669DOC_END
5670
5671NAME: cache_effective_group
5672TYPE: string
5673DEFAULT: none
5674DEFAULT_DOC: Use system group memberships of the cache_effective_user account
5675LOC: Config.effectiveGroup
5676DOC_START
5677 Squid sets the GID to the effective user's default group ID
5678 (taken from the password file) and supplementary group list
5679 from the groups membership.
5680
5681 If you want Squid to run with a specific GID regardless of
5682 the group memberships of the effective user then set this
5683 to the group (or GID) you want Squid to run as. When set
5684 all other group privileges of the effective user are ignored
5685 and only this GID is effective. If Squid is not started as
5686 root the user starting Squid MUST be member of the specified
5687 group.
5688
5689 This option is not recommended by the Squid Team.
5690 Our preference is for administrators to configure a secure
5691 user account for squid with UID/GID matching system policies.
5692DOC_END
5693
5694NAME: httpd_suppress_version_string
5695COMMENT: on|off
5696TYPE: onoff
5697DEFAULT: off
5698LOC: Config.onoff.httpd_suppress_version_string
5699DOC_START
5700 Suppress Squid version string info in HTTP headers and HTML error pages.
5701DOC_END
5702
5703NAME: visible_hostname
5704TYPE: string
5705LOC: Config.visibleHostname
5706DEFAULT: none
5707DEFAULT_DOC: Automatically detect the system host name
5708DOC_START
5709 If you want to present a special hostname in error messages, etc,
5710 define this. Otherwise, the return value of gethostname()
5711 will be used. If you have multiple caches in a cluster and
5712 get errors about IP-forwarding you must set them to have individual
5713 names with this setting.
5714DOC_END
5715
5716NAME: unique_hostname
5717TYPE: string
5718LOC: Config.uniqueHostname
5719DEFAULT: none
5720DEFAULT_DOC: Copy the value from visible_hostname
5721DOC_START
5722 If you want to have multiple machines with the same
5723 'visible_hostname' you must give each machine a different
5724 'unique_hostname' so forwarding loops can be detected.
5725DOC_END
5726
5727NAME: hostname_aliases
5728TYPE: wordlist
5729LOC: Config.hostnameAliases
5730DEFAULT: none
5731DOC_START
5732 A list of other DNS names your cache has.
5733DOC_END
5734
5735NAME: umask
5736TYPE: int
5737LOC: Config.umask
5738DEFAULT: 027
5739DOC_START
5740 Minimum umask which should be enforced while the proxy
5741 is running, in addition to the umask set at startup.
5742
5743 For a traditional octal representation of umasks, start
5744 your value with 0.
5745DOC_END
5746
5747COMMENT_START
5748 OPTIONS FOR THE CACHE REGISTRATION SERVICE
5749 -----------------------------------------------------------------------------
5750
5751 This section contains parameters for the (optional) cache
5752 announcement service. This service is provided to help
5753 cache administrators locate one another in order to join or
5754 create cache hierarchies.
5755
5756 An 'announcement' message is sent (via UDP) to the registration
5757 service by Squid. By default, the announcement message is NOT
5758 SENT unless you enable it with 'announce_period' below.
5759
5760 The announcement message includes your hostname, plus the
5761 following information from this configuration file:
5762
5763 http_port
5764 icp_port
5765 cache_mgr
5766
5767 All current information is processed regularly and made
5768 available on the Web at http://www.ircache.net/Cache/Tracker/.
5769COMMENT_END
5770
5771NAME: announce_period
5772TYPE: time_t
5773LOC: Config.Announce.period
5774DEFAULT: 0
5775DEFAULT_DOC: Announcement messages disabled.
5776DOC_START
5777 This is how frequently to send cache announcements.
5778
5779 To enable announcing your cache, just set an announce period.
5780
5781 Example:
5782 announce_period 1 day
5783DOC_END
5784
5785NAME: announce_host
5786TYPE: string
5787DEFAULT: tracker.ircache.net
5788LOC: Config.Announce.host
5789DOC_START
5790 Set the hostname where announce registration messages will be sent.
5791
5792 See also announce_port and announce_file
5793DOC_END
5794
5795NAME: announce_file
5796TYPE: string
5797DEFAULT: none
5798LOC: Config.Announce.file
5799DOC_START
5800 The contents of this file will be included in the announce
5801 registration messages.
5802DOC_END
5803
5804NAME: announce_port
5805TYPE: u_short
5806DEFAULT: 3131
5807LOC: Config.Announce.port
5808DOC_START
5809 Set the port where announce registration messages will be sent.
5810
5811 See also announce_host and announce_file
5812DOC_END
5813
5814COMMENT_START
5815 HTTPD-ACCELERATOR OPTIONS
5816 -----------------------------------------------------------------------------
5817COMMENT_END
5818
5819NAME: httpd_accel_surrogate_id
5820TYPE: string
5821DEFAULT: none
5822DEFAULT_DOC: visible_hostname is used if no specific ID is set.
5823LOC: Config.Accel.surrogate_id
5824DOC_START
5825 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
5826 need an identification token to allow control targeting. Because
5827 a farm of surrogates may all perform the same tasks, they may share
5828 an identification token.
5829DOC_END
5830
5831NAME: http_accel_surrogate_remote
5832COMMENT: on|off
5833TYPE: onoff
5834DEFAULT: off
5835LOC: Config.onoff.surrogate_is_remote
5836DOC_START
5837 Remote surrogates (such as those in a CDN) honour the header
5838 "Surrogate-Control: no-store-remote".
5839
5840 Set this to on to have squid behave as a remote surrogate.
5841DOC_END
5842
5843NAME: esi_parser
5844IFDEF: USE_SQUID_ESI
5845COMMENT: libxml2|expat|custom
5846TYPE: string
5847LOC: ESIParser::Type
5848DEFAULT: custom
5849DOC_START
5850 ESI markup is not strictly XML compatible. The custom ESI parser
5851 will give higher performance, but cannot handle non ASCII character
5852 encodings.
5853DOC_END
5854
5855COMMENT_START
5856 DELAY POOL PARAMETERS
5857 -----------------------------------------------------------------------------
5858COMMENT_END
5859
5860NAME: delay_pools
5861TYPE: delay_pool_count
5862DEFAULT: 0
5863IFDEF: USE_DELAY_POOLS
5864LOC: Config.Delay
5865DOC_START
5866 This represents the number of delay pools to be used. For example,
5867 if you have one class 2 delay pool and one class 3 delays pool, you
5868 have a total of 2 delay pools.
5869
5870 See also delay_parameters, delay_class, delay_access for pool
5871 configuration details.
5872DOC_END
5873
5874NAME: delay_class
5875TYPE: delay_pool_class
5876DEFAULT: none
5877IFDEF: USE_DELAY_POOLS
5878LOC: Config.Delay
5879DOC_START
5880 This defines the class of each delay pool. There must be exactly one
5881 delay_class line for each delay pool. For example, to define two
5882 delay pools, one of class 2 and one of class 3, the settings above
5883 and here would be:
5884
5885 Example:
5886 delay_pools 4 # 4 delay pools
5887 delay_class 1 2 # pool 1 is a class 2 pool
5888 delay_class 2 3 # pool 2 is a class 3 pool
5889 delay_class 3 4 # pool 3 is a class 4 pool
5890 delay_class 4 5 # pool 4 is a class 5 pool
5891
5892 The delay pool classes are:
5893
5894 class 1 Everything is limited by a single aggregate
5895 bucket.
5896
5897 class 2 Everything is limited by a single aggregate
5898 bucket as well as an "individual" bucket chosen
5899 from bits 25 through 32 of the IPv4 address.
5900
5901 class 3 Everything is limited by a single aggregate
5902 bucket as well as a "network" bucket chosen
5903 from bits 17 through 24 of the IP address and a
5904 "individual" bucket chosen from bits 17 through
5905 32 of the IPv4 address.
5906
5907 class 4 Everything in a class 3 delay pool, with an
5908 additional limit on a per user basis. This
5909 only takes effect if the username is established
5910 in advance - by forcing authentication in your
5911 http_access rules.
5912
5913 class 5 Requests are grouped according their tag (see
5914 external_acl's tag= reply).
5915
5916
5917 Each pool also requires a delay_parameters directive to configure the pool size
5918 and speed limits used whenever the pool is applied to a request. Along with
5919 a set of delay_access directives to determine when it is used.
5920
5921 NOTE: If an IP address is a.b.c.d
5922 -> bits 25 through 32 are "d"
5923 -> bits 17 through 24 are "c"
5924 -> bits 17 through 32 are "c * 256 + d"
5925
5926 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
5927 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
5928
5929 This clause only supports fast acl types.
5930 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5931
5932 See also delay_parameters and delay_access.
5933DOC_END
5934
5935NAME: delay_access
5936TYPE: delay_pool_access
5937DEFAULT: none
5938DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
5939IFDEF: USE_DELAY_POOLS
5940LOC: Config.Delay
5941DOC_START
5942 This is used to determine which delay pool a request falls into.
5943
5944 delay_access is sorted per pool and the matching starts with pool 1,
5945 then pool 2, ..., and finally pool N. The first delay pool where the
5946 request is allowed is selected for the request. If it does not allow
5947 the request to any pool then the request is not delayed (default).
5948
5949 For example, if you want some_big_clients in delay
5950 pool 1 and lotsa_little_clients in delay pool 2:
5951
5952 delay_access 1 allow some_big_clients
5953 delay_access 1 deny all
5954 delay_access 2 allow lotsa_little_clients
5955 delay_access 2 deny all
5956 delay_access 3 allow authenticated_clients
5957
5958 See also delay_parameters and delay_class.
5959
5960DOC_END
5961
5962NAME: delay_parameters
5963TYPE: delay_pool_rates
5964DEFAULT: none
5965IFDEF: USE_DELAY_POOLS
5966LOC: Config.Delay
5967DOC_START
5968 This defines the parameters for a delay pool. Each delay pool has
5969 a number of "buckets" associated with it, as explained in the
5970 description of delay_class.
5971
5972 For a class 1 delay pool, the syntax is:
5973 delay_pools pool 1
5974 delay_parameters pool aggregate
5975
5976 For a class 2 delay pool:
5977 delay_pools pool 2
5978 delay_parameters pool aggregate individual
5979
5980 For a class 3 delay pool:
5981 delay_pools pool 3
5982 delay_parameters pool aggregate network individual
5983
5984 For a class 4 delay pool:
5985 delay_pools pool 4
5986 delay_parameters pool aggregate network individual user
5987
5988 For a class 5 delay pool:
5989 delay_pools pool 5
5990 delay_parameters pool tagrate
5991
5992 The option variables are:
5993
5994 pool a pool number - ie, a number between 1 and the
5995 number specified in delay_pools as used in
5996 delay_class lines.
5997
5998 aggregate the speed limit parameters for the aggregate bucket
5999 (class 1, 2, 3).
6000
6001 individual the speed limit parameters for the individual
6002 buckets (class 2, 3).
6003
6004 network the speed limit parameters for the network buckets
6005 (class 3).
6006
6007 user the speed limit parameters for the user buckets
6008 (class 4).
6009
6010 tagrate the speed limit parameters for the tag buckets
6011 (class 5).
6012
6013 A pair of delay parameters is written restore/maximum, where restore is
6014 the number of bytes (not bits - modem and network speeds are usually
6015 quoted in bits) per second placed into the bucket, and maximum is the
6016 maximum number of bytes which can be in the bucket at any time.
6017
6018 There must be one delay_parameters line for each delay pool.
6019
6020
6021 For example, if delay pool number 1 is a class 2 delay pool as in the
6022 above example, and is being used to strictly limit each host to 64Kbit/sec
6023 (plus overheads), with no overall limit, the line is:
6024
6025 delay_parameters 1 -1/-1 8000/8000
6026
6027 Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
6028
6029 Note that the figure -1 is used to represent "unlimited".
6030
6031
6032 And, if delay pool number 2 is a class 3 delay pool as in the above
6033 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
6034 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
6035 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
6036 to permit a decent web page to be downloaded at a decent speed
6037 (if the network is not being limited due to overuse) but slow down
6038 large downloads more significantly:
6039
6040 delay_parameters 2 32000/32000 8000/8000 600/8000
6041
6042 Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
6043 8 x 8000 KByte/sec -> 64Kbit/sec.
6044 8 x 600 Byte/sec -> 4800bit/sec.
6045
6046
6047 Finally, for a class 4 delay pool as in the example - each user will
6048 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
6049
6050 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
6051
6052
6053 See also delay_class and delay_access.
6054
6055DOC_END
6056
6057NAME: delay_initial_bucket_level
6058COMMENT: (percent, 0-100)
6059TYPE: u_short
6060DEFAULT: 50
6061IFDEF: USE_DELAY_POOLS
6062LOC: Config.Delay.initial
6063DOC_START
6064 The initial bucket percentage is used to determine how much is put
6065 in each bucket when squid starts, is reconfigured, or first notices
6066 a host accessing it (in class 2 and class 3, individual hosts and
6067 networks only have buckets associated with them once they have been
6068 "seen" by squid).
6069DOC_END
6070
6071COMMENT_START
6072 CLIENT DELAY POOL PARAMETERS
6073 -----------------------------------------------------------------------------
6074COMMENT_END
6075
6076NAME: client_delay_pools
6077TYPE: client_delay_pool_count
6078DEFAULT: 0
6079IFDEF: USE_DELAY_POOLS
6080LOC: Config.ClientDelay
6081DOC_START
6082 This option specifies the number of client delay pools used. It must
6083 preceed other client_delay_* options.
6084
6085 Example:
6086 client_delay_pools 2
6087
6088 See also client_delay_parameters and client_delay_access.
6089DOC_END
6090
6091NAME: client_delay_initial_bucket_level
6092COMMENT: (percent, 0-no_limit)
6093TYPE: u_short
6094DEFAULT: 50
6095IFDEF: USE_DELAY_POOLS
6096LOC: Config.ClientDelay.initial
6097DOC_START
6098 This option determines the initial bucket size as a percentage of
6099 max_bucket_size from client_delay_parameters. Buckets are created
6100 at the time of the "first" connection from the matching IP. Idle
6101 buckets are periodically deleted up.
6102
6103 You can specify more than 100 percent but note that such "oversized"
6104 buckets are not refilled until their size goes down to max_bucket_size
6105 from client_delay_parameters.
6106
6107 Example:
6108 client_delay_initial_bucket_level 50
6109DOC_END
6110
6111NAME: client_delay_parameters
6112TYPE: client_delay_pool_rates
6113DEFAULT: none
6114IFDEF: USE_DELAY_POOLS
6115LOC: Config.ClientDelay
6116DOC_START
6117
6118 This option configures client-side bandwidth limits using the
6119 following format:
6120
6121 client_delay_parameters pool speed_limit max_bucket_size
6122
6123 pool is an integer ID used for client_delay_access matching.
6124
6125 speed_limit is bytes added to the bucket per second.
6126
6127 max_bucket_size is the maximum size of a bucket, enforced after any
6128 speed_limit additions.
6129
6130 Please see the delay_parameters option for more information and
6131 examples.
6132
6133 Example:
6134 client_delay_parameters 1 1024 2048
6135 client_delay_parameters 2 51200 16384
6136
6137 See also client_delay_access.
6138
6139DOC_END
6140
6141NAME: client_delay_access
6142TYPE: client_delay_pool_access
6143DEFAULT: none
6144DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
6145IFDEF: USE_DELAY_POOLS
6146LOC: Config.ClientDelay
6147DOC_START
6148 This option determines the client-side delay pool for the
6149 request:
6150
6151 client_delay_access pool_ID allow|deny acl_name
6152
6153 All client_delay_access options are checked in their pool ID
6154 order, starting with pool 1. The first checked pool with allowed
6155 request is selected for the request. If no ACL matches or there
6156 are no client_delay_access options, the request bandwidth is not
6157 limited.
6158
6159 The ACL-selected pool is then used to find the
6160 client_delay_parameters for the request. Client-side pools are
6161 not used to aggregate clients. Clients are always aggregated
6162 based on their source IP addresses (one bucket per source IP).
6163
6164 This clause only supports fast acl types.
6165 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6166 Additionally, only the client TCP connection details are available.
6167 ACLs testing HTTP properties will not work.
6168
6169 Please see delay_access for more examples.
6170
6171 Example:
6172 client_delay_access 1 allow low_rate_network
6173 client_delay_access 2 allow vips_network
6174
6175
6176 See also client_delay_parameters and client_delay_pools.
6177DOC_END
6178
6179COMMENT_START
6180 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
6181 -----------------------------------------------------------------------------
6182COMMENT_END
6183
6184NAME: wccp_router
6185TYPE: address
6186LOC: Config.Wccp.router
6187DEFAULT: any_addr
6188DEFAULT_DOC: WCCP disabled.
6189IFDEF: USE_WCCP
6190DOC_START
6191 Use this option to define your WCCP ``home'' router for
6192 Squid.
6193
6194 wccp_router supports a single WCCP(v1) router
6195
6196 wccp2_router supports multiple WCCPv2 routers
6197
6198 only one of the two may be used at the same time and defines
6199 which version of WCCP to use.
6200DOC_END
6201
6202NAME: wccp2_router
6203TYPE: IpAddress_list
6204LOC: Config.Wccp2.router
6205DEFAULT: none
6206DEFAULT_DOC: WCCPv2 disabled.
6207IFDEF: USE_WCCPv2
6208DOC_START
6209 Use this option to define your WCCP ``home'' router for
6210 Squid.
6211
6212 wccp_router supports a single WCCP(v1) router
6213
6214 wccp2_router supports multiple WCCPv2 routers
6215
6216 only one of the two may be used at the same time and defines
6217 which version of WCCP to use.
6218DOC_END
6219
6220NAME: wccp_version
6221TYPE: int
6222LOC: Config.Wccp.version
6223DEFAULT: 4
6224IFDEF: USE_WCCP
6225DOC_START
6226 This directive is only relevant if you need to set up WCCP(v1)
6227 to some very old and end-of-life Cisco routers. In all other
6228 setups it must be left unset or at the default setting.
6229 It defines an internal version in the WCCP(v1) protocol,
6230 with version 4 being the officially documented protocol.
6231
6232 According to some users, Cisco IOS 11.2 and earlier only
6233 support WCCP version 3. If you're using that or an earlier
6234 version of IOS, you may need to change this value to 3, otherwise
6235 do not specify this parameter.
6236DOC_END
6237
6238NAME: wccp2_rebuild_wait
6239TYPE: onoff
6240LOC: Config.Wccp2.rebuildwait
6241DEFAULT: on
6242IFDEF: USE_WCCPv2
6243DOC_START
6244 If this is enabled Squid will wait for the cache dir rebuild to finish
6245 before sending the first wccp2 HereIAm packet
6246DOC_END
6247
6248NAME: wccp2_forwarding_method
6249TYPE: wccp2_method
6250LOC: Config.Wccp2.forwarding_method
6251DEFAULT: gre
6252IFDEF: USE_WCCPv2
6253DOC_START
6254 WCCP2 allows the setting of forwarding methods between the
6255 router/switch and the cache. Valid values are as follows:
6256
6257 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6258 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6259
6260 Currently (as of IOS 12.4) cisco routers only support GRE.
6261 Cisco switches only support the L2 redirect assignment method.
6262DOC_END
6263
6264NAME: wccp2_return_method
6265TYPE: wccp2_method
6266LOC: Config.Wccp2.return_method
6267DEFAULT: gre
6268IFDEF: USE_WCCPv2
6269DOC_START
6270 WCCP2 allows the setting of return methods between the
6271 router/switch and the cache for packets that the cache
6272 decides not to handle. Valid values are as follows:
6273
6274 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6275 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6276
6277 Currently (as of IOS 12.4) cisco routers only support GRE.
6278 Cisco switches only support the L2 redirect assignment.
6279
6280 If the "ip wccp redirect exclude in" command has been
6281 enabled on the cache interface, then it is still safe for
6282 the proxy server to use a l2 redirect method even if this
6283 option is set to GRE.
6284DOC_END
6285
6286NAME: wccp2_assignment_method
6287TYPE: wccp2_amethod
6288LOC: Config.Wccp2.assignment_method
6289DEFAULT: hash
6290IFDEF: USE_WCCPv2
6291DOC_START
6292 WCCP2 allows the setting of methods to assign the WCCP hash
6293 Valid values are as follows:
6294
6295 hash - Hash assignment
6296 mask - Mask assignment
6297
6298 As a general rule, cisco routers support the hash assignment method
6299 and cisco switches support the mask assignment method.
6300DOC_END
6301
6302NAME: wccp2_service
6303TYPE: wccp2_service
6304LOC: Config.Wccp2.info
6305DEFAULT_IF_NONE: standard 0
6306DEFAULT_DOC: Use the 'web-cache' standard service.
6307IFDEF: USE_WCCPv2
6308DOC_START
6309 WCCP2 allows for multiple traffic services. There are two
6310 types: "standard" and "dynamic". The standard type defines
6311 one service id - http (id 0). The dynamic service ids can be from
6312 51 to 255 inclusive. In order to use a dynamic service id
6313 one must define the type of traffic to be redirected; this is done
6314 using the wccp2_service_info option.
6315
6316 The "standard" type does not require a wccp2_service_info option,
6317 just specifying the service id will suffice.
6318
6319 MD5 service authentication can be enabled by adding
6320 "password=<password>" to the end of this service declaration.
6321
6322 Examples:
6323
6324 wccp2_service standard 0 # for the 'web-cache' standard service
6325 wccp2_service dynamic 80 # a dynamic service type which will be
6326 # fleshed out with subsequent options.
6327 wccp2_service standard 0 password=foo
6328DOC_END
6329
6330NAME: wccp2_service_info
6331TYPE: wccp2_service_info
6332LOC: Config.Wccp2.info
6333DEFAULT: none
6334IFDEF: USE_WCCPv2
6335DOC_START
6336 Dynamic WCCPv2 services require further information to define the
6337 traffic you wish to have diverted.
6338
6339 The format is:
6340
6341 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6342 priority=<priority> ports=<port>,<port>..
6343
6344 The relevant WCCPv2 flags:
6345 + src_ip_hash, dst_ip_hash
6346 + source_port_hash, dst_port_hash
6347 + src_ip_alt_hash, dst_ip_alt_hash
6348 + src_port_alt_hash, dst_port_alt_hash
6349 + ports_source
6350
6351 The port list can be one to eight entries.
6352
6353 Example:
6354
6355 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6356 priority=240 ports=80
6357
6358 Note: the service id must have been defined by a previous
6359 'wccp2_service dynamic <id>' entry.
6360DOC_END
6361
6362NAME: wccp2_weight
6363TYPE: int
6364LOC: Config.Wccp2.weight
6365DEFAULT: 10000
6366IFDEF: USE_WCCPv2
6367DOC_START
6368 Each cache server gets assigned a set of the destination
6369 hash proportional to their weight.
6370DOC_END
6371
6372NAME: wccp_address
6373TYPE: address
6374LOC: Config.Wccp.address
6375DEFAULT: 0.0.0.0
6376DEFAULT_DOC: Address selected by the operating system.
6377IFDEF: USE_WCCP
6378DOC_START
6379 Use this option if you require WCCPv2 to use a specific
6380 interface address.
6381
6382 The default behavior is to not bind to any specific address.
6383DOC_END
6384
6385NAME: wccp2_address
6386TYPE: address
6387LOC: Config.Wccp2.address
6388DEFAULT: 0.0.0.0
6389DEFAULT_DOC: Address selected by the operating system.
6390IFDEF: USE_WCCPv2
6391DOC_START
6392 Use this option if you require WCCP to use a specific
6393 interface address.
6394
6395 The default behavior is to not bind to any specific address.
6396DOC_END
6397
6398COMMENT_START
6399 PERSISTENT CONNECTION HANDLING
6400 -----------------------------------------------------------------------------
6401
6402 Also see "pconn_timeout" in the TIMEOUTS section
6403COMMENT_END
6404
6405NAME: client_persistent_connections
6406TYPE: onoff
6407LOC: Config.onoff.client_pconns
6408DEFAULT: on
6409DOC_START
6410 Persistent connection support for clients.
6411 Squid uses persistent connections (when allowed). You can use
6412 this option to disable persistent connections with clients.
6413DOC_END
6414
6415NAME: server_persistent_connections
6416TYPE: onoff
6417LOC: Config.onoff.server_pconns
6418DEFAULT: on
6419DOC_START
6420 Persistent connection support for servers.
6421 Squid uses persistent connections (when allowed). You can use
6422 this option to disable persistent connections with servers.
6423DOC_END
6424
6425NAME: persistent_connection_after_error
6426TYPE: onoff
6427LOC: Config.onoff.error_pconns
6428DEFAULT: on
6429DOC_START
6430 With this directive the use of persistent connections after
6431 HTTP errors can be disabled. Useful if you have clients
6432 who fail to handle errors on persistent connections proper.
6433DOC_END
6434
6435NAME: detect_broken_pconn
6436TYPE: onoff
6437LOC: Config.onoff.detect_broken_server_pconns
6438DEFAULT: off
6439DOC_START
6440 Some servers have been found to incorrectly signal the use
6441 of HTTP/1.0 persistent connections even on replies not
6442 compatible, causing significant delays. This server problem
6443 has mostly been seen on redirects.
6444
6445 By enabling this directive Squid attempts to detect such
6446 broken replies and automatically assume the reply is finished
6447 after 10 seconds timeout.
6448DOC_END
6449
6450COMMENT_START
6451 CACHE DIGEST OPTIONS
6452 -----------------------------------------------------------------------------
6453COMMENT_END
6454
6455NAME: digest_generation
6456IFDEF: USE_CACHE_DIGESTS
6457TYPE: onoff
6458LOC: Config.onoff.digest_generation
6459DEFAULT: on
6460DOC_START
6461 This controls whether the server will generate a Cache Digest
6462 of its contents. By default, Cache Digest generation is
6463 enabled if Squid is compiled with --enable-cache-digests defined.
6464DOC_END
6465
6466NAME: digest_bits_per_entry
6467IFDEF: USE_CACHE_DIGESTS
6468TYPE: int
6469LOC: Config.digest.bits_per_entry
6470DEFAULT: 5
6471DOC_START
6472 This is the number of bits of the server's Cache Digest which
6473 will be associated with the Digest entry for a given HTTP
6474 Method and URL (public key) combination. The default is 5.
6475DOC_END
6476
6477NAME: digest_rebuild_period
6478IFDEF: USE_CACHE_DIGESTS
6479COMMENT: (seconds)
6480TYPE: time_t
6481LOC: Config.digest.rebuild_period
6482DEFAULT: 1 hour
6483DOC_START
6484 This is the wait time between Cache Digest rebuilds.
6485DOC_END
6486
6487NAME: digest_rewrite_period
6488COMMENT: (seconds)
6489IFDEF: USE_CACHE_DIGESTS
6490TYPE: time_t
6491LOC: Config.digest.rewrite_period
6492DEFAULT: 1 hour
6493DOC_START
6494 This is the wait time between Cache Digest writes to
6495 disk.
6496DOC_END
6497
6498NAME: digest_swapout_chunk_size
6499COMMENT: (bytes)
6500TYPE: b_size_t
6501IFDEF: USE_CACHE_DIGESTS
6502LOC: Config.digest.swapout_chunk_size
6503DEFAULT: 4096 bytes
6504DOC_START
6505 This is the number of bytes of the Cache Digest to write to
6506 disk at a time. It defaults to 4096 bytes (4KB), the Squid
6507 default swap page.
6508DOC_END
6509
6510NAME: digest_rebuild_chunk_percentage
6511COMMENT: (percent, 0-100)
6512IFDEF: USE_CACHE_DIGESTS
6513TYPE: int
6514LOC: Config.digest.rebuild_chunk_percentage
6515DEFAULT: 10
6516DOC_START
6517 This is the percentage of the Cache Digest to be scanned at a
6518 time. By default it is set to 10% of the Cache Digest.
6519DOC_END
6520
6521COMMENT_START
6522 SNMP OPTIONS
6523 -----------------------------------------------------------------------------
6524COMMENT_END
6525
6526NAME: snmp_port
6527TYPE: u_short
6528LOC: Config.Port.snmp
6529DEFAULT: 0
6530DEFAULT_DOC: SNMP disabled.
6531IFDEF: SQUID_SNMP
6532DOC_START
6533 The port number where Squid listens for SNMP requests. To enable
6534 SNMP support set this to a suitable port number. Port number
6535 3401 is often used for the Squid SNMP agent. By default it's
6536 set to "0" (disabled)
6537
6538 Example:
6539 snmp_port 3401
6540DOC_END
6541
6542NAME: snmp_access
6543TYPE: acl_access
6544LOC: Config.accessList.snmp
6545DEFAULT: none
6546DEFAULT_DOC: Deny, unless rules exist in squid.conf.
6547IFDEF: SQUID_SNMP
6548DOC_START
6549 Allowing or denying access to the SNMP port.
6550
6551 All access to the agent is denied by default.
6552 usage:
6553
6554 snmp_access allow|deny [!]aclname ...
6555
6556 This clause only supports fast acl types.
6557 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6558
6559Example:
6560 snmp_access allow snmppublic localhost
6561 snmp_access deny all
6562DOC_END
6563
6564NAME: snmp_incoming_address
6565TYPE: address
6566LOC: Config.Addrs.snmp_incoming
6567DEFAULT: any_addr
6568DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
6569IFDEF: SQUID_SNMP
6570DOC_START
6571 Just like 'udp_incoming_address', but for the SNMP port.
6572
6573 snmp_incoming_address is used for the SNMP socket receiving
6574 messages from SNMP agents.
6575
6576 The default snmp_incoming_address is to listen on all
6577 available network interfaces.
6578DOC_END
6579
6580NAME: snmp_outgoing_address
6581TYPE: address
6582LOC: Config.Addrs.snmp_outgoing
6583DEFAULT: no_addr
6584DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
6585IFDEF: SQUID_SNMP
6586DOC_START
6587 Just like 'udp_outgoing_address', but for the SNMP port.
6588
6589 snmp_outgoing_address is used for SNMP packets returned to SNMP
6590 agents.
6591
6592 If snmp_outgoing_address is not set it will use the same socket
6593 as snmp_incoming_address. Only change this if you want to have
6594 SNMP replies sent using another address than where this Squid
6595 listens for SNMP queries.
6596
6597 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
6598 the same value since they both use the same port.
6599DOC_END
6600
6601COMMENT_START
6602 ICP OPTIONS
6603 -----------------------------------------------------------------------------
6604COMMENT_END
6605
6606NAME: icp_port udp_port
6607TYPE: u_short
6608DEFAULT: 0
6609DEFAULT_DOC: ICP disabled.
6610LOC: Config.Port.icp
6611DOC_START
6612 The port number where Squid sends and receives ICP queries to
6613 and from neighbor caches. The standard UDP port for ICP is 3130.
6614
6615 Example:
6616 icp_port @DEFAULT_ICP_PORT@
6617DOC_END
6618
6619NAME: htcp_port
6620IFDEF: USE_HTCP
6621TYPE: u_short
6622DEFAULT: 0
6623DEFAULT_DOC: HTCP disabled.
6624LOC: Config.Port.htcp
6625DOC_START
6626 The port number where Squid sends and receives HTCP queries to
6627 and from neighbor caches. To turn it on you want to set it to
6628 4827.
6629
6630 Example:
6631 htcp_port 4827
6632DOC_END
6633
6634NAME: log_icp_queries
6635COMMENT: on|off
6636TYPE: onoff
6637DEFAULT: on
6638LOC: Config.onoff.log_udp
6639DOC_START
6640 If set, ICP queries are logged to access.log. You may wish
6641 do disable this if your ICP load is VERY high to speed things
6642 up or to simplify log analysis.
6643DOC_END
6644
6645NAME: udp_incoming_address
6646TYPE: address
6647LOC:Config.Addrs.udp_incoming
6648DEFAULT: any_addr
6649DEFAULT_DOC: Accept packets from all machine interfaces.
6650DOC_START
6651 udp_incoming_address is used for UDP packets received from other
6652 caches.
6653
6654 The default behavior is to not bind to any specific address.
6655
6656 Only change this if you want to have all UDP queries received on
6657 a specific interface/address.
6658
6659 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
6660 modules. Altering it will affect all of them in the same manner.
6661
6662 see also; udp_outgoing_address
6663
6664 NOTE, udp_incoming_address and udp_outgoing_address can not
6665 have the same value since they both use the same port.
6666DOC_END
6667
6668NAME: udp_outgoing_address
6669TYPE: address
6670LOC: Config.Addrs.udp_outgoing
6671DEFAULT: no_addr
6672DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
6673DOC_START
6674 udp_outgoing_address is used for UDP packets sent out to other
6675 caches.
6676
6677 The default behavior is to not bind to any specific address.
6678
6679 Instead it will use the same socket as udp_incoming_address.
6680 Only change this if you want to have UDP queries sent using another
6681 address than where this Squid listens for UDP queries from other
6682 caches.
6683
6684 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
6685 modules. Altering it will affect all of them in the same manner.
6686
6687 see also; udp_incoming_address
6688
6689 NOTE, udp_incoming_address and udp_outgoing_address can not
6690 have the same value since they both use the same port.
6691DOC_END
6692
6693NAME: icp_hit_stale
6694COMMENT: on|off
6695TYPE: onoff
6696DEFAULT: off
6697LOC: Config.onoff.icp_hit_stale
6698DOC_START
6699 If you want to return ICP_HIT for stale cache objects, set this
6700 option to 'on'. If you have sibling relationships with caches
6701 in other administrative domains, this should be 'off'. If you only
6702 have sibling relationships with caches under your control,
6703 it is probably okay to set this to 'on'.
6704 If set to 'on', your siblings should use the option "allow-miss"
6705 on their cache_peer lines for connecting to you.
6706DOC_END
6707
6708NAME: minimum_direct_hops
6709TYPE: int
6710DEFAULT: 4
6711LOC: Config.minDirectHops
6712DOC_START
6713 If using the ICMP pinging stuff, do direct fetches for sites
6714 which are no more than this many hops away.
6715DOC_END
6716
6717NAME: minimum_direct_rtt
6718COMMENT: (msec)
6719TYPE: int
6720DEFAULT: 400
6721LOC: Config.minDirectRtt
6722DOC_START
6723 If using the ICMP pinging stuff, do direct fetches for sites
6724 which are no more than this many rtt milliseconds away.
6725DOC_END
6726
6727NAME: netdb_low
6728TYPE: int
6729DEFAULT: 900
6730LOC: Config.Netdb.low
6731DOC_START
6732 The low water mark for the ICMP measurement database.
6733
6734 Note: high watermark controlled by netdb_high directive.
6735
6736 These watermarks are counts, not percents. The defaults are
6737 (low) 900 and (high) 1000. When the high water mark is
6738 reached, database entries will be deleted until the low
6739 mark is reached.
6740DOC_END
6741
6742NAME: netdb_high
6743TYPE: int
6744DEFAULT: 1000
6745LOC: Config.Netdb.high
6746DOC_START
6747 The high water mark for the ICMP measurement database.
6748
6749 Note: low watermark controlled by netdb_low directive.
6750
6751 These watermarks are counts, not percents. The defaults are
6752 (low) 900 and (high) 1000. When the high water mark is
6753 reached, database entries will be deleted until the low
6754 mark is reached.
6755DOC_END
6756
6757NAME: netdb_ping_period
6758TYPE: time_t
6759LOC: Config.Netdb.period
6760DEFAULT: 5 minutes
6761DOC_START
6762 The minimum period for measuring a site. There will be at
6763 least this much delay between successive pings to the same
6764 network. The default is five minutes.
6765DOC_END
6766
6767NAME: query_icmp
6768COMMENT: on|off
6769TYPE: onoff
6770DEFAULT: off
6771LOC: Config.onoff.query_icmp
6772DOC_START
6773 If you want to ask your peers to include ICMP data in their ICP
6774 replies, enable this option.
6775
6776 If your peer has configured Squid (during compilation) with
6777 '--enable-icmp' that peer will send ICMP pings to origin server
6778 sites of the URLs it receives. If you enable this option the
6779 ICP replies from that peer will include the ICMP data (if available).
6780 Then, when choosing a parent cache, Squid will choose the parent with
6781 the minimal RTT to the origin server. When this happens, the
6782 hierarchy field of the access.log will be
6783 "CLOSEST_PARENT_MISS". This option is off by default.
6784DOC_END
6785
6786NAME: test_reachability
6787COMMENT: on|off
6788TYPE: onoff
6789DEFAULT: off
6790LOC: Config.onoff.test_reachability
6791DOC_START
6792 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
6793 instead of ICP_MISS if the target host is NOT in the ICMP
6794 database, or has a zero RTT.
6795DOC_END
6796
6797NAME: icp_query_timeout
6798COMMENT: (msec)
6799DEFAULT: 0
6800DEFAULT_DOC: Dynamic detection.
6801TYPE: int
6802LOC: Config.Timeout.icp_query
6803DOC_START
6804 Normally Squid will automatically determine an optimal ICP
6805 query timeout value based on the round-trip-time of recent ICP
6806 queries. If you want to override the value determined by
6807 Squid, set this 'icp_query_timeout' to a non-zero value. This
6808 value is specified in MILLISECONDS, so, to use a 2-second
6809 timeout (the old default), you would write:
6810
6811 icp_query_timeout 2000
6812DOC_END
6813
6814NAME: maximum_icp_query_timeout
6815COMMENT: (msec)
6816DEFAULT: 2000
6817TYPE: int
6818LOC: Config.Timeout.icp_query_max
6819DOC_START
6820 Normally the ICP query timeout is determined dynamically. But
6821 sometimes it can lead to very large values (say 5 seconds).
6822 Use this option to put an upper limit on the dynamic timeout
6823 value. Do NOT use this option to always use a fixed (instead
6824 of a dynamic) timeout value. To set a fixed timeout see the
6825 'icp_query_timeout' directive.
6826DOC_END
6827
6828NAME: minimum_icp_query_timeout
6829COMMENT: (msec)
6830DEFAULT: 5
6831TYPE: int
6832LOC: Config.Timeout.icp_query_min
6833DOC_START
6834 Normally the ICP query timeout is determined dynamically. But
6835 sometimes it can lead to very small timeouts, even lower than
6836 the normal latency variance on your link due to traffic.
6837 Use this option to put an lower limit on the dynamic timeout
6838 value. Do NOT use this option to always use a fixed (instead
6839 of a dynamic) timeout value. To set a fixed timeout see the
6840 'icp_query_timeout' directive.
6841DOC_END
6842
6843NAME: background_ping_rate
6844COMMENT: time-units
6845TYPE: time_t
6846DEFAULT: 10 seconds
6847LOC: Config.backgroundPingRate
6848DOC_START
6849 Controls how often the ICP pings are sent to siblings that
6850 have background-ping set.
6851DOC_END
6852
6853COMMENT_START
6854 MULTICAST ICP OPTIONS
6855 -----------------------------------------------------------------------------
6856COMMENT_END
6857
6858NAME: mcast_groups
6859TYPE: wordlist
6860LOC: Config.mcast_group_list
6861DEFAULT: none
6862DOC_START
6863 This tag specifies a list of multicast groups which your server
6864 should join to receive multicasted ICP queries.
6865
6866 NOTE! Be very careful what you put here! Be sure you
6867 understand the difference between an ICP _query_ and an ICP
6868 _reply_. This option is to be set only if you want to RECEIVE
6869 multicast queries. Do NOT set this option to SEND multicast
6870 ICP (use cache_peer for that). ICP replies are always sent via
6871 unicast, so this option does not affect whether or not you will
6872 receive replies from multicast group members.
6873
6874 You must be very careful to NOT use a multicast address which
6875 is already in use by another group of caches.
6876
6877 If you are unsure about multicast, please read the Multicast
6878 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
6879
6880 Usage: mcast_groups 239.128.16.128 224.0.1.20
6881
6882 By default, Squid doesn't listen on any multicast groups.
6883DOC_END
6884
6885NAME: mcast_miss_addr
6886IFDEF: MULTICAST_MISS_STREAM
6887TYPE: address
6888LOC: Config.mcast_miss.addr
6889DEFAULT: no_addr
6890DEFAULT_DOC: disabled.
6891DOC_START
6892 If you enable this option, every "cache miss" URL will
6893 be sent out on the specified multicast address.
6894
6895 Do not enable this option unless you are are absolutely
6896 certain you understand what you are doing.
6897DOC_END
6898
6899NAME: mcast_miss_ttl
6900IFDEF: MULTICAST_MISS_STREAM
6901TYPE: u_short
6902LOC: Config.mcast_miss.ttl
6903DEFAULT: 16
6904DOC_START
6905 This is the time-to-live value for packets multicasted
6906 when multicasting off cache miss URLs is enabled. By
6907 default this is set to 'site scope', i.e. 16.
6908DOC_END
6909
6910NAME: mcast_miss_port
6911IFDEF: MULTICAST_MISS_STREAM
6912TYPE: u_short
6913LOC: Config.mcast_miss.port
6914DEFAULT: 3135
6915DOC_START
6916 This is the port number to be used in conjunction with
6917 'mcast_miss_addr'.
6918DOC_END
6919
6920NAME: mcast_miss_encode_key
6921IFDEF: MULTICAST_MISS_STREAM
6922TYPE: string
6923LOC: Config.mcast_miss.encode_key
6924DEFAULT: XXXXXXXXXXXXXXXX
6925DOC_START
6926 The URLs that are sent in the multicast miss stream are
6927 encrypted. This is the encryption key.
6928DOC_END
6929
6930NAME: mcast_icp_query_timeout
6931COMMENT: (msec)
6932DEFAULT: 2000
6933TYPE: int
6934LOC: Config.Timeout.mcast_icp_query
6935DOC_START
6936 For multicast peers, Squid regularly sends out ICP "probes" to
6937 count how many other peers are listening on the given multicast
6938 address. This value specifies how long Squid should wait to
6939 count all the replies. The default is 2000 msec, or 2
6940 seconds.
6941DOC_END
6942
6943COMMENT_START
6944 INTERNAL ICON OPTIONS
6945 -----------------------------------------------------------------------------
6946COMMENT_END
6947
6948NAME: icon_directory
6949TYPE: string
6950LOC: Config.icons.directory
6951DEFAULT: @DEFAULT_ICON_DIR@
6952DOC_START
6953 Where the icons are stored. These are normally kept in
6954 @DEFAULT_ICON_DIR@
6955DOC_END
6956
6957NAME: global_internal_static
6958TYPE: onoff
6959LOC: Config.onoff.global_internal_static
6960DEFAULT: on
6961DOC_START
6962 This directive controls is Squid should intercept all requests for
6963 /squid-internal-static/ no matter which host the URL is requesting
6964 (default on setting), or if nothing special should be done for
6965 such URLs (off setting). The purpose of this directive is to make
6966 icons etc work better in complex cache hierarchies where it may
6967 not always be possible for all corners in the cache mesh to reach
6968 the server generating a directory listing.
6969DOC_END
6970
6971NAME: short_icon_urls
6972TYPE: onoff
6973LOC: Config.icons.use_short_names
6974DEFAULT: on
6975DOC_START
6976 If this is enabled Squid will use short URLs for icons.
6977 If disabled it will revert to the old behavior of including
6978 it's own name and port in the URL.
6979
6980 If you run a complex cache hierarchy with a mix of Squid and
6981 other proxies you may need to disable this directive.
6982DOC_END
6983
6984COMMENT_START
6985 ERROR PAGE OPTIONS
6986 -----------------------------------------------------------------------------
6987COMMENT_END
6988
6989NAME: error_directory
6990TYPE: string
6991LOC: Config.errorDirectory
6992DEFAULT: none
6993DEFAULT_DOC: Send error pages in the clients preferred language
6994DOC_START
6995 If you wish to create your own versions of the default
6996 error files to customize them to suit your company copy
6997 the error/template files to another directory and point
6998 this tag at them.
6999
7000 WARNING: This option will disable multi-language support
7001 on error pages if used.
7002
7003 The squid developers are interested in making squid available in
7004 a wide variety of languages. If you are making translations for a
7005 language that Squid does not currently provide please consider
7006 contributing your translation back to the project.
7007 http://wiki.squid-cache.org/Translations
7008
7009 The squid developers working on translations are happy to supply drop-in
7010 translated error files in exchange for any new language contributions.
7011DOC_END
7012
7013NAME: error_default_language
7014IFDEF: USE_ERR_LOCALES
7015TYPE: string
7016LOC: Config.errorDefaultLanguage
7017DEFAULT: none
7018DEFAULT_DOC: Generate English language pages.
7019DOC_START
7020 Set the default language which squid will send error pages in
7021 if no existing translation matches the clients language
7022 preferences.
7023
7024 If unset (default) generic English will be used.
7025
7026 The squid developers are interested in making squid available in
7027 a wide variety of languages. If you are interested in making
7028 translations for any language see the squid wiki for details.
7029 http://wiki.squid-cache.org/Translations
7030DOC_END
7031
7032NAME: error_log_languages
7033IFDEF: USE_ERR_LOCALES
7034TYPE: onoff
7035LOC: Config.errorLogMissingLanguages
7036DEFAULT: on
7037DOC_START
7038 Log to cache.log what languages users are attempting to
7039 auto-negotiate for translations.
7040
7041 Successful negotiations are not logged. Only failures
7042 have meaning to indicate that Squid may need an upgrade
7043 of its error page translations.
7044DOC_END
7045
7046NAME: err_page_stylesheet
7047TYPE: string
7048LOC: Config.errorStylesheet
7049DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
7050DOC_START
7051 CSS Stylesheet to pattern the display of Squid default error pages.
7052
7053 For information on CSS see http://www.w3.org/Style/CSS/
7054DOC_END
7055
7056NAME: err_html_text
7057TYPE: eol
7058LOC: Config.errHtmlText
7059DEFAULT: none
7060DOC_START
7061 HTML text to include in error messages. Make this a "mailto"
7062 URL to your admin address, or maybe just a link to your
7063 organizations Web page.
7064
7065 To include this in your error messages, you must rewrite
7066 the error template files (found in the "errors" directory).
7067 Wherever you want the 'err_html_text' line to appear,
7068 insert a %L tag in the error template file.
7069DOC_END
7070
7071NAME: email_err_data
7072COMMENT: on|off
7073TYPE: onoff
7074LOC: Config.onoff.emailErrData
7075DEFAULT: on
7076DOC_START
7077 If enabled, information about the occurred error will be
7078 included in the mailto links of the ERR pages (if %W is set)
7079 so that the email body contains the data.
7080 Syntax is <A HREF="mailto:%w%W">%w</A>
7081DOC_END
7082
7083NAME: deny_info
7084TYPE: denyinfo
7085LOC: Config.denyInfoList
7086DEFAULT: none
7087DOC_START
7088 Usage: deny_info err_page_name acl
7089 or deny_info http://... acl
7090 or deny_info TCP_RESET acl
7091
7092 This can be used to return a ERR_ page for requests which
7093 do not pass the 'http_access' rules. Squid remembers the last
7094 acl it evaluated in http_access, and if a 'deny_info' line exists
7095 for that ACL Squid returns a corresponding error page.
7096
7097 The acl is typically the last acl on the http_access deny line which
7098 denied access. The exceptions to this rule are:
7099 - When Squid needs to request authentication credentials. It's then
7100 the first authentication related acl encountered
7101 - When none of the http_access lines matches. It's then the last
7102 acl processed on the last http_access line.
7103 - When the decision to deny access was made by an adaptation service,
7104 the acl name is the corresponding eCAP or ICAP service_name.
7105
7106 NP: If providing your own custom error pages with error_directory
7107 you may also specify them by your custom file name:
7108 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
7109
7110 By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
7111 may be specified by prefixing the file name with the code and a colon.
7112 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
7113
7114 Alternatively you can tell Squid to reset the TCP connection
7115 by specifying TCP_RESET.
7116
7117 Or you can specify an error URL or URL pattern. The browsers will
7118 get redirected to the specified URL after formatting tags have
7119 been replaced. Redirect will be done with 302 or 307 according to
7120 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
7121 the URL. e.g. 303:http://example.com/
7122
7123 URL FORMAT TAGS:
7124 %a - username (if available. Password NOT included)
7125 %B - FTP path URL
7126 %e - Error number
7127 %E - Error description
7128 %h - Squid hostname
7129 %H - Request domain name
7130 %i - Client IP Address
7131 %M - Request Method
7132 %o - Message result from external ACL helper
7133 %p - Request Port number
7134 %P - Request Protocol name
7135 %R - Request URL path
7136 %T - Timestamp in RFC 1123 format
7137 %U - Full canonical URL from client
7138 (HTTPS URLs terminate with *)
7139 %u - Full canonical URL from client
7140 %w - Admin email from squid.conf
7141 %x - Error name
7142 %% - Literal percent (%) code
7143
7144DOC_END
7145
7146COMMENT_START
7147 OPTIONS INFLUENCING REQUEST FORWARDING
7148 -----------------------------------------------------------------------------
7149COMMENT_END
7150
7151NAME: nonhierarchical_direct
7152TYPE: onoff
7153LOC: Config.onoff.nonhierarchical_direct
7154DEFAULT: on
7155DOC_START
7156 By default, Squid will send any non-hierarchical requests
7157 (matching hierarchy_stoplist or not cacheable request type) direct
7158 to origin servers.
7159
7160 When this is set to "off", Squid will prefer to send these
7161 requests to parents.
7162
7163 Note that in most configurations, by turning this off you will only
7164 add latency to these request without any improvement in global hit
7165 ratio.
7166
7167 This option only sets a preference. If the parent is unavailable a
7168 direct connection to the origin server may still be attempted. To
7169 completely prevent direct connections use never_direct.
7170DOC_END
7171
7172NAME: prefer_direct
7173TYPE: onoff
7174LOC: Config.onoff.prefer_direct
7175DEFAULT: off
7176DOC_START
7177 Normally Squid tries to use parents for most requests. If you for some
7178 reason like it to first try going direct and only use a parent if
7179 going direct fails set this to on.
7180
7181 By combining nonhierarchical_direct off and prefer_direct on you
7182 can set up Squid to use a parent as a backup path if going direct
7183 fails.
7184
7185 Note: If you want Squid to use parents for all requests see
7186 the never_direct directive. prefer_direct only modifies how Squid
7187 acts on cacheable requests.
7188DOC_END
7189
7190NAME: always_direct
7191TYPE: acl_access
7192LOC: Config.accessList.AlwaysDirect
7193DEFAULT: none
7194DEFAULT_DOC: Prevent any cache_peer being used for this request.
7195DOC_START
7196 Usage: always_direct allow|deny [!]aclname ...
7197
7198 Here you can use ACL elements to specify requests which should
7199 ALWAYS be forwarded by Squid to the origin servers without using
7200 any peers. For example, to always directly forward requests for
7201 local servers ignoring any parents or siblings you may have use
7202 something like:
7203
7204 acl local-servers dstdomain my.domain.net
7205 always_direct allow local-servers
7206
7207 To always forward FTP requests directly, use
7208
7209 acl FTP proto FTP
7210 always_direct allow FTP
7211
7212 NOTE: There is a similar, but opposite option named
7213 'never_direct'. You need to be aware that "always_direct deny
7214 foo" is NOT the same thing as "never_direct allow foo". You
7215 may need to use a deny rule to exclude a more-specific case of
7216 some other rule. Example:
7217
7218 acl local-external dstdomain external.foo.net
7219 acl local-servers dstdomain .foo.net
7220 always_direct deny local-external
7221 always_direct allow local-servers
7222
7223 NOTE: If your goal is to make the client forward the request
7224 directly to the origin server bypassing Squid then this needs
7225 to be done in the client configuration. Squid configuration
7226 can only tell Squid how Squid should fetch the object.
7227
7228 NOTE: This directive is not related to caching. The replies
7229 is cached as usual even if you use always_direct. To not cache
7230 the replies see the 'cache' directive.
7231
7232 This clause supports both fast and slow acl types.
7233 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7234DOC_END
7235
7236NAME: never_direct
7237TYPE: acl_access
7238LOC: Config.accessList.NeverDirect
7239DEFAULT: none
7240DEFAULT_DOC: Allow DNS results to be used for this request.
7241DOC_START
7242 Usage: never_direct allow|deny [!]aclname ...
7243
7244 never_direct is the opposite of always_direct. Please read
7245 the description for always_direct if you have not already.
7246
7247 With 'never_direct' you can use ACL elements to specify
7248 requests which should NEVER be forwarded directly to origin
7249 servers. For example, to force the use of a proxy for all
7250 requests, except those in your local domain use something like:
7251
7252 acl local-servers dstdomain .foo.net
7253 never_direct deny local-servers
7254 never_direct allow all
7255
7256 or if Squid is inside a firewall and there are local intranet
7257 servers inside the firewall use something like:
7258
7259 acl local-intranet dstdomain .foo.net
7260 acl local-external dstdomain external.foo.net
7261 always_direct deny local-external
7262 always_direct allow local-intranet
7263 never_direct allow all
7264
7265 This clause supports both fast and slow acl types.
7266 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7267DOC_END
7268
7269COMMENT_START
7270 ADVANCED NETWORKING OPTIONS
7271 -----------------------------------------------------------------------------
7272COMMENT_END
7273
7274NAME: incoming_udp_average incoming_icp_average
7275TYPE: int
7276DEFAULT: 6
7277LOC: Config.comm_incoming.udp.average
7278DOC_START
7279 Heavy voodoo here. I can't even believe you are reading this.
7280 Are you crazy? Don't even think about adjusting these unless
7281 you understand the algorithms in comm_select.c first!
7282DOC_END
7283
7284NAME: incoming_tcp_average incoming_http_average
7285TYPE: int
7286DEFAULT: 4
7287LOC: Config.comm_incoming.tcp.average
7288DOC_START
7289 Heavy voodoo here. I can't even believe you are reading this.
7290 Are you crazy? Don't even think about adjusting these unless
7291 you understand the algorithms in comm_select.c first!
7292DOC_END
7293
7294NAME: incoming_dns_average
7295TYPE: int
7296DEFAULT: 4
7297LOC: Config.comm_incoming.dns.average
7298DOC_START
7299 Heavy voodoo here. I can't even believe you are reading this.
7300 Are you crazy? Don't even think about adjusting these unless
7301 you understand the algorithms in comm_select.c first!
7302DOC_END
7303
7304NAME: min_udp_poll_cnt min_icp_poll_cnt
7305TYPE: int
7306DEFAULT: 8
7307LOC: Config.comm_incoming.udp.min_poll
7308DOC_START
7309 Heavy voodoo here. I can't even believe you are reading this.
7310 Are you crazy? Don't even think about adjusting these unless
7311 you understand the algorithms in comm_select.c first!
7312DOC_END
7313
7314NAME: min_dns_poll_cnt
7315TYPE: int
7316DEFAULT: 8
7317LOC: Config.comm_incoming.dns.min_poll
7318DOC_START
7319 Heavy voodoo here. I can't even believe you are reading this.
7320 Are you crazy? Don't even think about adjusting these unless
7321 you understand the algorithms in comm_select.c first!
7322DOC_END
7323
7324NAME: min_tcp_poll_cnt min_http_poll_cnt
7325TYPE: int
7326DEFAULT: 8
7327LOC: Config.comm_incoming.tcp.min_poll
7328DOC_START
7329 Heavy voodoo here. I can't even believe you are reading this.
7330 Are you crazy? Don't even think about adjusting these unless
7331 you understand the algorithms in comm_select.c first!
7332DOC_END
7333
7334NAME: accept_filter
7335TYPE: string
7336DEFAULT: none
7337LOC: Config.accept_filter
7338DOC_START
7339 FreeBSD:
7340
7341 The name of an accept(2) filter to install on Squid's
7342 listen socket(s). This feature is perhaps specific to
7343 FreeBSD and requires support in the kernel.
7344
7345 The 'httpready' filter delays delivering new connections
7346 to Squid until a full HTTP request has been received.
7347 See the accf_http(9) man page for details.
7348
7349 The 'dataready' filter delays delivering new connections
7350 to Squid until there is some data to process.
7351 See the accf_dataready(9) man page for details.
7352
7353 Linux:
7354
7355 The 'data' filter delays delivering of new connections
7356 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
7357 You may optionally specify a number of seconds to wait by
7358 'data=N' where N is the number of seconds. Defaults to 30
7359 if not specified. See the tcp(7) man page for details.
7360EXAMPLE:
7361# FreeBSD
7362accept_filter httpready
7363# Linux
7364accept_filter data
7365DOC_END
7366
7367NAME: client_ip_max_connections
7368TYPE: int
7369LOC: Config.client_ip_max_connections
7370DEFAULT: -1
7371DEFAULT_DOC: No limit.
7372DOC_START
7373 Set an absolute limit on the number of connections a single
7374 client IP can use. Any more than this and Squid will begin to drop
7375 new connections from the client until it closes some links.
7376
7377 Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
7378 connections from the client. For finer control use the ACL access controls.
7379
7380 Requires client_db to be enabled (the default).
7381
7382 WARNING: This may noticably slow down traffic received via external proxies
7383 or NAT devices and cause them to rebound error messages back to their clients.
7384DOC_END
7385
7386NAME: tcp_recv_bufsize
7387COMMENT: (bytes)
7388TYPE: b_size_t
7389DEFAULT: 0 bytes
7390DEFAULT_DOC: Use operating system TCP defaults.
7391LOC: Config.tcpRcvBufsz
7392DOC_START
7393 Size of receive buffer to set for TCP sockets. Probably just
7394 as easy to change your kernel's default.
7395 Omit from squid.conf to use the default buffer size.
7396DOC_END
7397
7398COMMENT_START
7399 ICAP OPTIONS
7400 -----------------------------------------------------------------------------
7401COMMENT_END
7402
7403NAME: icap_enable
7404TYPE: onoff
7405IFDEF: ICAP_CLIENT
7406COMMENT: on|off
7407LOC: Adaptation::Icap::TheConfig.onoff
7408DEFAULT: off
7409DOC_START
7410 If you want to enable the ICAP module support, set this to on.
7411DOC_END
7412
7413NAME: icap_connect_timeout
7414TYPE: time_t
7415DEFAULT: none
7416LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
7417IFDEF: ICAP_CLIENT
7418DOC_START
7419 This parameter specifies how long to wait for the TCP connect to
7420 the requested ICAP server to complete before giving up and either
7421 terminating the HTTP transaction or bypassing the failure.
7422
7423 The default for optional services is peer_connect_timeout.
7424 The default for essential services is connect_timeout.
7425 If this option is explicitly set, its value applies to all services.
7426DOC_END
7427
7428NAME: icap_io_timeout
7429COMMENT: time-units
7430TYPE: time_t
7431DEFAULT: none
7432DEFAULT_DOC: Use read_timeout.
7433LOC: Adaptation::Icap::TheConfig.io_timeout_raw
7434IFDEF: ICAP_CLIENT
7435DOC_START
7436 This parameter specifies how long to wait for an I/O activity on
7437 an established, active ICAP connection before giving up and
7438 either terminating the HTTP transaction or bypassing the
7439 failure.
7440DOC_END
7441
7442NAME: icap_service_failure_limit
7443COMMENT: limit [in memory-depth time-units]
7444TYPE: icap_service_failure_limit
7445IFDEF: ICAP_CLIENT
7446LOC: Adaptation::Icap::TheConfig
7447DEFAULT: 10
7448DOC_START
7449 The limit specifies the number of failures that Squid tolerates
7450 when establishing a new TCP connection with an ICAP service. If
7451 the number of failures exceeds the limit, the ICAP service is
7452 not used for new ICAP requests until it is time to refresh its
7453 OPTIONS.
7454
7455 A negative value disables the limit. Without the limit, an ICAP
7456 service will not be considered down due to connectivity failures
7457 between ICAP OPTIONS requests.
7458
7459 Squid forgets ICAP service failures older than the specified
7460 value of memory-depth. The memory fading algorithm
7461 is approximate because Squid does not remember individual
7462 errors but groups them instead, splitting the option
7463 value into ten time slots of equal length.
7464
7465 When memory-depth is 0 and by default this option has no
7466 effect on service failure expiration.
7467
7468 Squid always forgets failures when updating service settings
7469 using an ICAP OPTIONS transaction, regardless of this option
7470 setting.
7471
7472 For example,
7473 # suspend service usage after 10 failures in 5 seconds:
7474 icap_service_failure_limit 10 in 5 seconds
7475DOC_END
7476
7477NAME: icap_service_revival_delay
7478TYPE: int
7479IFDEF: ICAP_CLIENT
7480LOC: Adaptation::Icap::TheConfig.service_revival_delay
7481DEFAULT: 180
7482DOC_START
7483 The delay specifies the number of seconds to wait after an ICAP
7484 OPTIONS request failure before requesting the options again. The
7485 failed ICAP service is considered "down" until fresh OPTIONS are
7486 fetched.
7487
7488 The actual delay cannot be smaller than the hardcoded minimum
7489 delay of 30 seconds.
7490DOC_END
7491
7492NAME: icap_preview_enable
7493TYPE: onoff
7494IFDEF: ICAP_CLIENT
7495COMMENT: on|off
7496LOC: Adaptation::Icap::TheConfig.preview_enable
7497DEFAULT: on
7498DOC_START
7499 The ICAP Preview feature allows the ICAP server to handle the
7500 HTTP message by looking only at the beginning of the message body
7501 or even without receiving the body at all. In some environments,
7502 previews greatly speedup ICAP processing.
7503
7504 During an ICAP OPTIONS transaction, the server may tell Squid what
7505 HTTP messages should be previewed and how big the preview should be.
7506 Squid will not use Preview if the server did not request one.
7507
7508 To disable ICAP Preview for all ICAP services, regardless of
7509 individual ICAP server OPTIONS responses, set this option to "off".
7510Example:
7511icap_preview_enable off
7512DOC_END
7513
7514NAME: icap_preview_size
7515TYPE: int
7516IFDEF: ICAP_CLIENT
7517LOC: Adaptation::Icap::TheConfig.preview_size
7518DEFAULT: -1
7519DEFAULT_DOC: No preview sent.
7520DOC_START
7521 The default size of preview data to be sent to the ICAP server.
7522 This value might be overwritten on a per server basis by OPTIONS requests.
7523DOC_END
7524
7525NAME: icap_206_enable
7526TYPE: onoff
7527IFDEF: ICAP_CLIENT
7528COMMENT: on|off
7529LOC: Adaptation::Icap::TheConfig.allow206_enable
7530DEFAULT: on
7531DOC_START
7532 206 (Partial Content) responses is an ICAP extension that allows the
7533 ICAP agents to optionally combine adapted and original HTTP message
7534 content. The decision to combine is postponed until the end of the
7535 ICAP response. Squid supports Partial Content extension by default.
7536
7537 Activation of the Partial Content extension is negotiated with each
7538 ICAP service during OPTIONS exchange. Most ICAP servers should handle
7539 negotation correctly even if they do not support the extension, but
7540 some might fail. To disable Partial Content support for all ICAP
7541 services and to avoid any negotiation, set this option to "off".
7542
7543 Example:
7544 icap_206_enable off
7545DOC_END
7546
7547NAME: icap_default_options_ttl
7548TYPE: int
7549IFDEF: ICAP_CLIENT
7550LOC: Adaptation::Icap::TheConfig.default_options_ttl
7551DEFAULT: 60
7552DOC_START
7553 The default TTL value for ICAP OPTIONS responses that don't have
7554 an Options-TTL header.
7555DOC_END
7556
7557NAME: icap_persistent_connections
7558TYPE: onoff
7559IFDEF: ICAP_CLIENT
7560COMMENT: on|off
7561LOC: Adaptation::Icap::TheConfig.reuse_connections
7562DEFAULT: on
7563DOC_START
7564 Whether or not Squid should use persistent connections to
7565 an ICAP server.
7566DOC_END
7567
7568NAME: adaptation_send_client_ip icap_send_client_ip
7569TYPE: onoff
7570IFDEF: USE_ADAPTATION
7571COMMENT: on|off
7572LOC: Adaptation::Config::send_client_ip
7573DEFAULT: off
7574DOC_START
7575 If enabled, Squid shares HTTP client IP information with adaptation
7576 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
7577 For eCAP, Squid sets the libecap::metaClientIp transaction option.
7578
7579 See also: adaptation_uses_indirect_client
7580DOC_END
7581
7582NAME: adaptation_send_username icap_send_client_username
7583TYPE: onoff
7584IFDEF: USE_ADAPTATION
7585COMMENT: on|off
7586LOC: Adaptation::Config::send_username
7587DEFAULT: off
7588DOC_START
7589 This sends authenticated HTTP client username (if available) to
7590 the adaptation service.
7591
7592 For ICAP, the username value is encoded based on the
7593 icap_client_username_encode option and is sent using the header
7594 specified by the icap_client_username_header option.
7595DOC_END
7596
7597NAME: icap_client_username_header
7598TYPE: string
7599IFDEF: ICAP_CLIENT
7600LOC: Adaptation::Icap::TheConfig.client_username_header
7601DEFAULT: X-Client-Username
7602DOC_START
7603 ICAP request header name to use for adaptation_send_username.
7604DOC_END
7605
7606NAME: icap_client_username_encode
7607TYPE: onoff
7608IFDEF: ICAP_CLIENT
7609COMMENT: on|off
7610LOC: Adaptation::Icap::TheConfig.client_username_encode
7611DEFAULT: off
7612DOC_START
7613 Whether to base64 encode the authenticated client username.
7614DOC_END
7615
7616NAME: icap_service
7617TYPE: icap_service_type
7618IFDEF: ICAP_CLIENT
7619LOC: Adaptation::Icap::TheConfig
7620DEFAULT: none
7621DOC_START
7622 Defines a single ICAP service using the following format:
7623
7624 icap_service id vectoring_point uri [option ...]
7625
7626 id: ID
7627 an opaque identifier or name which is used to direct traffic to
7628 this specific service. Must be unique among all adaptation
7629 services in squid.conf.
7630
7631 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7632 This specifies at which point of transaction processing the
7633 ICAP service should be activated. *_postcache vectoring points
7634 are not yet supported.
7635
7636 uri: icap://servername:port/servicepath
7637 ICAP server and service location.
7638
7639 ICAP does not allow a single service to handle both REQMOD and RESPMOD
7640 transactions. Squid does not enforce that requirement. You can specify
7641 services with the same service_url and different vectoring_points. You
7642 can even specify multiple identical services as long as their
7643 service_names differ.
7644
7645
7646 Service options are separated by white space. ICAP services support
7647 the following name=value options:
7648
7649 bypass=on|off|1|0
7650 If set to 'on' or '1', the ICAP service is treated as
7651 optional. If the service cannot be reached or malfunctions,
7652 Squid will try to ignore any errors and process the message as
7653 if the service was not enabled. No all ICAP errors can be
7654 bypassed. If set to 0, the ICAP service is treated as
7655 essential and all ICAP errors will result in an error page
7656 returned to the HTTP client.
7657
7658 Bypass is off by default: services are treated as essential.
7659
7660 routing=on|off|1|0
7661 If set to 'on' or '1', the ICAP service is allowed to
7662 dynamically change the current message adaptation plan by
7663 returning a chain of services to be used next. The services
7664 are specified using the X-Next-Services ICAP response header
7665 value, formatted as a comma-separated list of service names.
7666 Each named service should be configured in squid.conf. Other
7667 services are ignored. An empty X-Next-Services value results
7668 in an empty plan which ends the current adaptation.
7669
7670 Dynamic adaptation plan may cross or cover multiple supported
7671 vectoring points in their natural processing order.
7672
7673 Routing is not allowed by default: the ICAP X-Next-Services
7674 response header is ignored.
7675
7676 ipv6=on|off
7677 Only has effect on split-stack systems. The default on those systems
7678 is to use IPv4-only connections. When set to 'on' this option will
7679 make Squid use IPv6-only connections to contact this ICAP service.
7680
7681 on-overload=block|bypass|wait|force
7682 If the service Max-Connections limit has been reached, do
7683 one of the following for each new ICAP transaction:
7684 * block: send an HTTP error response to the client
7685 * bypass: ignore the "over-connected" ICAP service
7686 * wait: wait (in a FIFO queue) for an ICAP connection slot
7687 * force: proceed, ignoring the Max-Connections limit
7688
7689 In SMP mode with N workers, each worker assumes the service
7690 connection limit is Max-Connections/N, even though not all
7691 workers may use a given service.
7692
7693 The default value is "bypass" if service is bypassable,
7694 otherwise it is set to "wait".
7695
7696
7697 max-conn=number
7698 Use the given number as the Max-Connections limit, regardless
7699 of the Max-Connections value given by the service, if any.
7700
7701 Older icap_service format without optional named parameters is
7702 deprecated but supported for backward compatibility.
7703
7704Example:
7705icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
7706icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
7707DOC_END
7708
7709NAME: icap_class
7710TYPE: icap_class_type
7711IFDEF: ICAP_CLIENT
7712LOC: none
7713DEFAULT: none
7714DOC_START
7715 This deprecated option was documented to define an ICAP service
7716 chain, even though it actually defined a set of similar, redundant
7717 services, and the chains were not supported.
7718
7719 To define a set of redundant services, please use the
7720 adaptation_service_set directive. For service chains, use
7721 adaptation_service_chain.
7722DOC_END
7723
7724NAME: icap_access
7725TYPE: icap_access_type
7726IFDEF: ICAP_CLIENT
7727LOC: none
7728DEFAULT: none
7729DOC_START
7730 This option is deprecated. Please use adaptation_access, which
7731 has the same ICAP functionality, but comes with better
7732 documentation, and eCAP support.
7733DOC_END
7734
7735COMMENT_START
7736 eCAP OPTIONS
7737 -----------------------------------------------------------------------------
7738COMMENT_END
7739
7740NAME: ecap_enable
7741TYPE: onoff
7742IFDEF: USE_ECAP
7743COMMENT: on|off
7744LOC: Adaptation::Ecap::TheConfig.onoff
7745DEFAULT: off
7746DOC_START
7747 Controls whether eCAP support is enabled.
7748DOC_END
7749
7750NAME: ecap_service
7751TYPE: ecap_service_type
7752IFDEF: USE_ECAP
7753LOC: Adaptation::Ecap::TheConfig
7754DEFAULT: none
7755DOC_START
7756 Defines a single eCAP service
7757
7758 ecap_service id vectoring_point uri [option ...]
7759
7760 id: ID
7761 an opaque identifier or name which is used to direct traffic to
7762 this specific service. Must be unique among all adaptation
7763 services in squid.conf.
7764
7765 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7766 This specifies at which point of transaction processing the
7767 eCAP service should be activated. *_postcache vectoring points
7768 are not yet supported.
7769
7770 uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
7771 Squid uses the eCAP service URI to match this configuration
7772 line with one of the dynamically loaded services. Each loaded
7773 eCAP service must have a unique URI. Obtain the right URI from
7774 the service provider.
7775
7776
7777 Service options are separated by white space. eCAP services support
7778 the following name=value options:
7779
7780 bypass=on|off|1|0
7781 If set to 'on' or '1', the eCAP service is treated as optional.
7782 If the service cannot be reached or malfunctions, Squid will try
7783 to ignore any errors and process the message as if the service
7784 was not enabled. No all eCAP errors can be bypassed.
7785 If set to 'off' or '0', the eCAP service is treated as essential
7786 and all eCAP errors will result in an error page returned to the
7787 HTTP client.
7788
7789 Bypass is off by default: services are treated as essential.
7790
7791 routing=on|off|1|0
7792 If set to 'on' or '1', the eCAP service is allowed to
7793 dynamically change the current message adaptation plan by
7794 returning a chain of services to be used next.
7795
7796 Dynamic adaptation plan may cross or cover multiple supported
7797 vectoring points in their natural processing order.
7798
7799 Routing is not allowed by default.
7800
7801 Older ecap_service format without optional named parameters is
7802 deprecated but supported for backward compatibility.
7803
7804
7805Example:
7806ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
7807ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
7808DOC_END
7809
7810NAME: loadable_modules
7811TYPE: wordlist
7812IFDEF: USE_LOADABLE_MODULES
7813LOC: Config.loadable_module_names
7814DEFAULT: none
7815DOC_START
7816 Instructs Squid to load the specified dynamic module(s) or activate
7817 preloaded module(s).
7818Example:
7819loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
7820DOC_END
7821
7822COMMENT_START
7823 MESSAGE ADAPTATION OPTIONS
7824 -----------------------------------------------------------------------------
7825COMMENT_END
7826
7827NAME: adaptation_service_set
7828TYPE: adaptation_service_set_type
7829IFDEF: USE_ADAPTATION
7830LOC: none
7831DEFAULT: none
7832DOC_START
7833
7834 Configures an ordered set of similar, redundant services. This is
7835 useful when hot standby or backup adaptation servers are available.
7836
7837 adaptation_service_set set_name service_name1 service_name2 ...
7838
7839 The named services are used in the set declaration order. The first
7840 applicable adaptation service from the set is used first. The next
7841 applicable service is tried if and only if the transaction with the
7842 previous service fails and the message waiting to be adapted is still
7843 intact.
7844
7845 When adaptation starts, broken services are ignored as if they were
7846 not a part of the set. A broken service is a down optional service.
7847
7848 The services in a set must be attached to the same vectoring point
7849 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7850
7851 If all services in a set are optional then adaptation failures are
7852 bypassable. If all services in the set are essential, then a
7853 transaction failure with one service may still be retried using
7854 another service from the set, but when all services fail, the master
7855 transaction fails as well.
7856
7857 A set may contain a mix of optional and essential services, but that
7858 is likely to lead to surprising results because broken services become
7859 ignored (see above), making previously bypassable failures fatal.
7860 Technically, it is the bypassability of the last failed service that
7861 matters.
7862
7863 See also: adaptation_access adaptation_service_chain
7864
7865Example:
7866adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
7867adaptation service_set svcLogger loggerLocal loggerRemote
7868DOC_END
7869
7870NAME: adaptation_service_chain
7871TYPE: adaptation_service_chain_type
7872IFDEF: USE_ADAPTATION
7873LOC: none
7874DEFAULT: none
7875DOC_START
7876
7877 Configures a list of complementary services that will be applied
7878 one-by-one, forming an adaptation chain or pipeline. This is useful
7879 when Squid must perform different adaptations on the same message.
7880
7881 adaptation_service_chain chain_name service_name1 svc_name2 ...
7882
7883 The named services are used in the chain declaration order. The first
7884 applicable adaptation service from the chain is used first. The next
7885 applicable service is applied to the successful adaptation results of
7886 the previous service in the chain.
7887
7888 When adaptation starts, broken services are ignored as if they were
7889 not a part of the chain. A broken service is a down optional service.
7890
7891 Request satisfaction terminates the adaptation chain because Squid
7892 does not currently allow declaration of RESPMOD services at the
7893 "reqmod_precache" vectoring point (see icap_service or ecap_service).
7894
7895 The services in a chain must be attached to the same vectoring point
7896 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7897
7898 A chain may contain a mix of optional and essential services. If an
7899 essential adaptation fails (or the failure cannot be bypassed for
7900 other reasons), the master transaction fails. Otherwise, the failure
7901 is bypassed as if the failed adaptation service was not in the chain.
7902
7903 See also: adaptation_access adaptation_service_set
7904
7905Example:
7906adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
7907DOC_END
7908
7909NAME: adaptation_access
7910TYPE: adaptation_access_type
7911IFDEF: USE_ADAPTATION
7912LOC: none
7913DEFAULT: none
7914DEFAULT_DOC: Allow, unless rules exist in squid.conf.
7915DOC_START
7916 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
7917
7918 adaptation_access service_name allow|deny [!]aclname...
7919 adaptation_access set_name allow|deny [!]aclname...
7920
7921 At each supported vectoring point, the adaptation_access
7922 statements are processed in the order they appear in this
7923 configuration file. Statements pointing to the following services
7924 are ignored (i.e., skipped without checking their ACL):
7925
7926 - services serving different vectoring points
7927 - "broken-but-bypassable" services
7928 - "up" services configured to ignore such transactions
7929 (e.g., based on the ICAP Transfer-Ignore header).
7930
7931 When a set_name is used, all services in the set are checked
7932 using the same rules, to find the first applicable one. See
7933 adaptation_service_set for details.
7934
7935 If an access list is checked and there is a match, the
7936 processing stops: For an "allow" rule, the corresponding
7937 adaptation service is used for the transaction. For a "deny"
7938 rule, no adaptation service is activated.
7939
7940 It is currently not possible to apply more than one adaptation
7941 service at the same vectoring point to the same HTTP transaction.
7942
7943 See also: icap_service and ecap_service
7944
7945Example:
7946adaptation_access service_1 allow all
7947DOC_END
7948
7949NAME: adaptation_service_iteration_limit
7950TYPE: int
7951IFDEF: USE_ADAPTATION
7952LOC: Adaptation::Config::service_iteration_limit
7953DEFAULT: 16
7954DOC_START
7955 Limits the number of iterations allowed when applying adaptation
7956 services to a message. If your longest adaptation set or chain
7957 may have more than 16 services, increase the limit beyond its
7958 default value of 16. If detecting infinite iteration loops sooner
7959 is critical, make the iteration limit match the actual number
7960 of services in your longest adaptation set or chain.
7961
7962 Infinite adaptation loops are most likely with routing services.
7963
7964 See also: icap_service routing=1
7965DOC_END
7966
7967NAME: adaptation_masterx_shared_names
7968TYPE: string
7969IFDEF: USE_ADAPTATION
7970LOC: Adaptation::Config::masterx_shared_name
7971DEFAULT: none
7972DOC_START
7973 For each master transaction (i.e., the HTTP request and response
7974 sequence, including all related ICAP and eCAP exchanges), Squid
7975 maintains a table of metadata. The table entries are (name, value)
7976 pairs shared among eCAP and ICAP exchanges. The table is destroyed
7977 with the master transaction.
7978
7979 This option specifies the table entry names that Squid must accept
7980 from and forward to the adaptation transactions.
7981
7982 An ICAP REQMOD or RESPMOD transaction may set an entry in the
7983 shared table by returning an ICAP header field with a name
7984 specified in adaptation_masterx_shared_names.
7985
7986 An eCAP REQMOD or RESPMOD transaction may set an entry in the
7987 shared table by implementing the libecap::visitEachOption() API
7988 to provide an option with a name specified in
7989 adaptation_masterx_shared_names.
7990
7991 Squid will store and forward the set entry to subsequent adaptation
7992 transactions within the same master transaction scope.
7993
7994 Only one shared entry name is supported at this time.
7995
7996Example:
7997# share authentication information among ICAP services
7998adaptation_masterx_shared_names X-Subscriber-ID
7999DOC_END
8000
8001NAME: adaptation_meta
8002TYPE: note
8003IFDEF: USE_ADAPTATION
8004LOC: Adaptation::Config::metaHeaders
8005DEFAULT: none
8006DOC_START
8007 This option allows Squid administrator to add custom ICAP request
8008 headers or eCAP options to Squid ICAP requests or eCAP transactions.
8009 Use it to pass custom authentication tokens and other
8010 transaction-state related meta information to an ICAP/eCAP service.
8011
8012 The addition of a meta header is ACL-driven:
8013 adaptation_meta name value [!]aclname ...
8014
8015 Processing for a given header name stops after the first ACL list match.
8016 Thus, it is impossible to add two headers with the same name. If no ACL
8017 lists match for a given header name, no such header is added. For
8018 example:
8019
8020 # do not debug transactions except for those that need debugging
8021 adaptation_meta X-Debug 1 needs_debugging
8022
8023 # log all transactions except for those that must remain secret
8024 adaptation_meta X-Log 1 !keep_secret
8025
8026 # mark transactions from users in the "G 1" group
8027 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
8028
8029 The "value" parameter may be a regular squid.conf token or a "double
8030 quoted string". Within the quoted string, use backslash (\) to escape
8031 any character, which is currently only useful for escaping backslashes
8032 and double quotes. For example,
8033 "this string has one backslash (\\) and two \"quotes\""
8034
8035 Used adaptation_meta header values may be logged via %note
8036 logformat code. If multiple adaptation_meta headers with the same name
8037 are used during master transaction lifetime, the header values are
8038 logged in the order they were used and duplicate values are ignored
8039 (only the first repeated value will be logged).
8040DOC_END
8041
8042NAME: icap_retry
8043TYPE: acl_access
8044IFDEF: ICAP_CLIENT
8045LOC: Adaptation::Icap::TheConfig.repeat
8046DEFAULT_IF_NONE: deny all
8047DOC_START
8048 This ACL determines which retriable ICAP transactions are
8049 retried. Transactions that received a complete ICAP response
8050 and did not have to consume or produce HTTP bodies to receive
8051 that response are usually retriable.
8052
8053 icap_retry allow|deny [!]aclname ...
8054
8055 Squid automatically retries some ICAP I/O timeouts and errors
8056 due to persistent connection race conditions.
8057
8058 See also: icap_retry_limit
8059DOC_END
8060
8061NAME: icap_retry_limit
8062TYPE: int
8063IFDEF: ICAP_CLIENT
8064LOC: Adaptation::Icap::TheConfig.repeat_limit
8065DEFAULT: 0
8066DEFAULT_DOC: No retries are allowed.
8067DOC_START
8068 Limits the number of retries allowed.
8069
8070 Communication errors due to persistent connection race
8071 conditions are unavoidable, automatically retried, and do not
8072 count against this limit.
8073
8074 See also: icap_retry
8075DOC_END
8076
8077
8078COMMENT_START
8079 DNS OPTIONS
8080 -----------------------------------------------------------------------------
8081COMMENT_END
8082
8083NAME: check_hostnames
8084TYPE: onoff
8085DEFAULT: off
8086LOC: Config.onoff.check_hostnames
8087DOC_START
8088 For security and stability reasons Squid can check
8089 hostnames for Internet standard RFC compliance. If you want
8090 Squid to perform these checks turn this directive on.
8091DOC_END
8092
8093NAME: allow_underscore
8094TYPE: onoff
8095DEFAULT: on
8096LOC: Config.onoff.allow_underscore
8097DOC_START
8098 Underscore characters is not strictly allowed in Internet hostnames
8099 but nevertheless used by many sites. Set this to off if you want
8100 Squid to be strict about the standard.
8101 This check is performed only when check_hostnames is set to on.
8102DOC_END
8103
8104NAME: cache_dns_program
8105TYPE: string
8106IFDEF: USE_DNSHELPER
8107DEFAULT: @DEFAULT_DNSSERVER@
8108LOC: Config.Program.dnsserver
8109DOC_START
8110 Specify the location of the executable for dnslookup process.
8111DOC_END
8112
8113NAME: dns_children
8114TYPE: HelperChildConfig
8115IFDEF: USE_DNSHELPER
8116DEFAULT: 32 startup=1 idle=1
8117LOC: Config.dnsChildren
8118DOC_START
8119 The maximum number of processes spawn to service DNS name lookups.
8120 If you limit it too few Squid will have to wait for them to process
8121 a backlog of requests, slowing it down. If you allow too many they
8122 will use RAM and other system resources noticably.
8123 The maximum this may be safely set to is 32.
8124
8125 The startup= and idle= options allow some measure of skew in your
8126 tuning.
8127
8128 startup=
8129
8130 Sets a minimum of how many processes are to be spawned when Squid
8131 starts or reconfigures. When set to zero the first request will
8132 cause spawning of the first child process to handle it.
8133
8134 Starting too few will cause an initial slowdown in traffic as Squid
8135 attempts to simultaneously spawn enough processes to cope.
8136
8137 idle=
8138
8139 Sets a minimum of how many processes Squid is to try and keep available
8140 at all times. When traffic begins to rise above what the existing
8141 processes can handle this many more will be spawned up to the maximum
8142 configured. A minimum setting of 1 is required.
8143DOC_END
8144
8145NAME: dns_retransmit_interval
8146TYPE: time_msec
8147DEFAULT: 5 seconds
8148LOC: Config.Timeout.idns_retransmit
8149IFDEF: !USE_DNSHELPER
8150DOC_START
8151 Initial retransmit interval for DNS queries. The interval is
8152 doubled each time all configured DNS servers have been tried.
8153DOC_END
8154
8155NAME: dns_timeout
8156TYPE: time_msec
8157DEFAULT: 30 seconds
8158LOC: Config.Timeout.idns_query
8159IFDEF: !USE_DNSHELPER
8160DOC_START
8161 DNS Query timeout. If no response is received to a DNS query
8162 within this time all DNS servers for the queried domain
8163 are assumed to be unavailable.
8164DOC_END
8165
8166NAME: dns_packet_max
8167TYPE: b_ssize_t
8168DEFAULT_DOC: EDNS disabled
8169DEFAULT: none
8170LOC: Config.dns.packet_max
8171IFDEF: !USE_DNSHELPER
8172DOC_START
8173 Maximum number of bytes packet size to advertise via EDNS.
8174 Set to "none" to disable EDNS large packet support.
8175
8176 For legacy reasons DNS UDP replies will default to 512 bytes which
8177 is too small for many responses. EDNS provides a means for Squid to
8178 negotiate receiving larger responses back immediately without having
8179 to failover with repeat requests. Responses larger than this limit
8180 will retain the old behaviour of failover to TCP DNS.
8181
8182 Squid has no real fixed limit internally, but allowing packet sizes
8183 over 1500 bytes requires network jumbogram support and is usually not
8184 necessary.
8185
8186 WARNING: The RFC also indicates that some older resolvers will reply
8187 with failure of the whole request if the extension is added. Some
8188 resolvers have already been identified which will reply with mangled
8189 EDNS response on occasion. Usually in response to many-KB jumbogram
8190 sizes being advertised by Squid.
8191 Squid will currently treat these both as an unable-to-resolve domain
8192 even if it would be resolvable without EDNS.
8193DOC_END
8194
8195NAME: dns_defnames
8196COMMENT: on|off
8197TYPE: onoff
8198DEFAULT: off
8199DEFAULT_DOC: Search for single-label domain names is disabled.
8200LOC: Config.onoff.res_defnames
8201DOC_START
8202 Normally the RES_DEFNAMES resolver option is disabled
8203 (see res_init(3)). This prevents caches in a hierarchy
8204 from interpreting single-component hostnames locally. To allow
8205 Squid to handle single-component names, enable this option.
8206DOC_END
8207
8208NAME: dns_nameservers
8209TYPE: wordlist
8210DEFAULT: none
8211DEFAULT_DOC: Use operating system definitions
8212LOC: Config.dns_nameservers
8213DOC_START
8214 Use this if you want to specify a list of DNS name servers
8215 (IP addresses) to use instead of those given in your
8216 /etc/resolv.conf file.
8217
8218 On Windows platforms, if no value is specified here or in
8219 the /etc/resolv.conf file, the list of DNS name servers are
8220 taken from the Windows registry, both static and dynamic DHCP
8221 configurations are supported.
8222
8223 Example: dns_nameservers 10.0.0.1 192.172.0.4
8224DOC_END
8225
8226NAME: hosts_file
8227TYPE: string
8228DEFAULT: @DEFAULT_HOSTS@
8229LOC: Config.etcHostsPath
8230DOC_START
8231 Location of the host-local IP name-address associations
8232 database. Most Operating Systems have such a file on different
8233 default locations:
8234 - Un*X & Linux: /etc/hosts
8235 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
8236 (%SystemRoot% value install default is c:\winnt)
8237 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
8238 (%SystemRoot% value install default is c:\windows)
8239 - Windows 9x/Me: %windir%\hosts
8240 (%windir% value is usually c:\windows)
8241 - Cygwin: /etc/hosts
8242
8243 The file contains newline-separated definitions, in the
8244 form ip_address_in_dotted_form name [name ...] names are
8245 whitespace-separated. Lines beginning with an hash (#)
8246 character are comments.
8247
8248 The file is checked at startup and upon configuration.
8249 If set to 'none', it won't be checked.
8250 If append_domain is used, that domain will be added to
8251 domain-local (i.e. not containing any dot character) host
8252 definitions.
8253DOC_END
8254
8255NAME: append_domain
8256TYPE: string
8257LOC: Config.appendDomain
8258DEFAULT: none
8259DEFAULT_DOC: Use operating system definitions
8260DOC_START
8261 Appends local domain name to hostnames without any dots in
8262 them. append_domain must begin with a period.
8263
8264 Be warned there are now Internet names with no dots in
8265 them using only top-domain names, so setting this may
8266 cause some Internet sites to become unavailable.
8267
8268Example:
8269 append_domain .yourdomain.com
8270DOC_END
8271
8272NAME: ignore_unknown_nameservers
8273TYPE: onoff
8274LOC: Config.onoff.ignore_unknown_nameservers
8275DEFAULT: on
8276IFDEF: !USE_DNSHELPER
8277DOC_START
8278 By default Squid checks that DNS responses are received
8279 from the same IP addresses they are sent to. If they
8280 don't match, Squid ignores the response and writes a warning
8281 message to cache.log. You can allow responses from unknown
8282 nameservers by setting this option to 'off'.
8283DOC_END
8284
8285NAME: dns_v4_first
8286TYPE: onoff
8287DEFAULT: off
8288LOC: Config.dns.v4_first
8289IFDEF: !USE_DNSHELPER
8290DOC_START
8291 With the IPv6 Internet being as fast or faster than IPv4 Internet
8292 for most networks Squid prefers to contact websites over IPv6.
8293
8294 This option reverses the order of preference to make Squid contact
8295 dual-stack websites over IPv4 first. Squid will still perform both
8296 IPv6 and IPv4 DNS lookups before connecting.
8297
8298 WARNING:
8299 This option will restrict the situations under which IPv6
8300 connectivity is used (and tested). Hiding network problems
8301 which would otherwise be detected and warned about.
8302DOC_END
8303
8304NAME: ipcache_size
8305COMMENT: (number of entries)
8306TYPE: int
8307DEFAULT: 1024
8308LOC: Config.ipcache.size
8309DOC_START
8310 Maximum number of DNS IP cache entries.
8311DOC_END
8312
8313NAME: ipcache_low
8314COMMENT: (percent)
8315TYPE: int
8316DEFAULT: 90
8317LOC: Config.ipcache.low
8318DOC_NONE
8319
8320NAME: ipcache_high
8321COMMENT: (percent)
8322TYPE: int
8323DEFAULT: 95
8324LOC: Config.ipcache.high
8325DOC_START
8326 The size, low-, and high-water marks for the IP cache.
8327DOC_END
8328
8329NAME: fqdncache_size
8330COMMENT: (number of entries)
8331TYPE: int
8332DEFAULT: 1024
8333LOC: Config.fqdncache.size
8334DOC_START
8335 Maximum number of FQDN cache entries.
8336DOC_END
8337
8338COMMENT_START
8339 MISCELLANEOUS
8340 -----------------------------------------------------------------------------
8341COMMENT_END
8342
8343NAME: memory_pools
8344COMMENT: on|off
8345TYPE: onoff
8346DEFAULT: on
8347LOC: Config.onoff.mem_pools
8348DOC_START
8349 If set, Squid will keep pools of allocated (but unused) memory
8350 available for future use. If memory is a premium on your
8351 system and you believe your malloc library outperforms Squid
8352 routines, disable this.
8353DOC_END
8354
8355NAME: memory_pools_limit
8356COMMENT: (bytes)
8357TYPE: b_int64_t
8358DEFAULT: 5 MB
8359LOC: Config.MemPools.limit
8360DOC_START
8361 Used only with memory_pools on:
8362 memory_pools_limit 50 MB
8363
8364 If set to a non-zero value, Squid will keep at most the specified
8365 limit of allocated (but unused) memory in memory pools. All free()
8366 requests that exceed this limit will be handled by your malloc
8367 library. Squid does not pre-allocate any memory, just safe-keeps
8368 objects that otherwise would be free()d. Thus, it is safe to set
8369 memory_pools_limit to a reasonably high value even if your
8370 configuration will use less memory.
8371
8372 If set to none, Squid will keep all memory it can. That is, there
8373 will be no limit on the total amount of memory used for safe-keeping.
8374
8375 To disable memory allocation optimization, do not set
8376 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
8377
8378 An overhead for maintaining memory pools is not taken into account
8379 when the limit is checked. This overhead is close to four bytes per
8380 object kept. However, pools may actually _save_ memory because of
8381 reduced memory thrashing in your malloc library.
8382DOC_END
8383
8384NAME: forwarded_for
8385COMMENT: on|off|transparent|truncate|delete
8386TYPE: string
8387DEFAULT: on
8388LOC: opt_forwarded_for
8389DOC_START
8390 If set to "on", Squid will append your client's IP address
8391 in the HTTP requests it forwards. By default it looks like:
8392
8393 X-Forwarded-For: 192.1.2.3
8394
8395 If set to "off", it will appear as
8396
8397 X-Forwarded-For: unknown
8398
8399 If set to "transparent", Squid will not alter the
8400 X-Forwarded-For header in any way.
8401
8402 If set to "delete", Squid will delete the entire
8403 X-Forwarded-For header.
8404
8405 If set to "truncate", Squid will remove all existing
8406 X-Forwarded-For entries, and place the client IP as the sole entry.
8407DOC_END
8408
8409NAME: cachemgr_passwd
8410TYPE: cachemgrpasswd
8411DEFAULT: none
8412DEFAULT_DOC: No password. Actions which require password are denied.
8413LOC: Config.passwd_list
8414DOC_START
8415 Specify passwords for cachemgr operations.
8416
8417 Usage: cachemgr_passwd password action action ...
8418
8419 Some valid actions are (see cache manager menu for a full list):
8420 5min
8421 60min
8422 asndb
8423 authenticator
8424 cbdata
8425 client_list
8426 comm_incoming
8427 config *
8428 counters
8429 delay
8430 digest_stats
8431 dns
8432 events
8433 filedescriptors
8434 fqdncache
8435 histograms
8436 http_headers
8437 info
8438 io
8439 ipcache
8440 mem
8441 menu
8442 netdb
8443 non_peers
8444 objects
8445 offline_toggle *
8446 pconn
8447 peer_select
8448 reconfigure *
8449 redirector
8450 refresh
8451 server_list
8452 shutdown *
8453 store_digest
8454 storedir
8455 utilization
8456 via_headers
8457 vm_objects
8458
8459 * Indicates actions which will not be performed without a
8460 valid password, others can be performed if not listed here.
8461
8462 To disable an action, set the password to "disable".
8463 To allow performing an action without a password, set the
8464 password to "none".
8465
8466 Use the keyword "all" to set the same password for all actions.
8467
8468Example:
8469 cachemgr_passwd secret shutdown
8470 cachemgr_passwd lesssssssecret info stats/objects
8471 cachemgr_passwd disable all
8472DOC_END
8473
8474NAME: client_db
8475COMMENT: on|off
8476TYPE: onoff
8477DEFAULT: on
8478LOC: Config.onoff.client_db
8479DOC_START
8480 If you want to disable collecting per-client statistics,
8481 turn off client_db here.
8482DOC_END
8483
8484NAME: refresh_all_ims
8485COMMENT: on|off
8486TYPE: onoff
8487DEFAULT: off
8488LOC: Config.onoff.refresh_all_ims
8489DOC_START
8490 When you enable this option, squid will always check
8491 the origin server for an update when a client sends an
8492 If-Modified-Since request. Many browsers use IMS
8493 requests when the user requests a reload, and this
8494 ensures those clients receive the latest version.
8495
8496 By default (off), squid may return a Not Modified response
8497 based on the age of the cached version.
8498DOC_END
8499
8500NAME: reload_into_ims
8501IFDEF: USE_HTTP_VIOLATIONS
8502COMMENT: on|off
8503TYPE: onoff
8504DEFAULT: off
8505LOC: Config.onoff.reload_into_ims
8506DOC_START
8507 When you enable this option, client no-cache or ``reload''
8508 requests will be changed to If-Modified-Since requests.
8509 Doing this VIOLATES the HTTP standard. Enabling this
8510 feature could make you liable for problems which it
8511 causes.
8512
8513 see also refresh_pattern for a more selective approach.
8514DOC_END
8515
8516NAME: connect_retries
8517TYPE: int
8518LOC: Config.connect_retries
8519DEFAULT: 0
8520DEFAULT_DOC: Do not retry failed connections.
8521DOC_START
8522 This sets the maximum number of connection attempts made for each
8523 TCP connection. The connect_retries attempts must all still
8524 complete within the connection timeout period.
8525
8526 The default is not to re-try if the first connection attempt fails.
8527 The (not recommended) maximum is 10 tries.
8528
8529 A warning message will be generated if it is set to a too-high
8530 value and the configured value will be over-ridden.
8531
8532 Note: These re-tries are in addition to forward_max_tries
8533 which limit how many different addresses may be tried to find
8534 a useful server.
8535DOC_END
8536
8537NAME: retry_on_error
8538TYPE: onoff
8539LOC: Config.retry.onerror
8540DEFAULT: off
8541DOC_START
8542 If set to ON Squid will automatically retry requests when
8543 receiving an error response with status 403 (Forbidden),
8544 500 (Internal Error), 501 or 503 (Service not available).
8545 Status 502 and 504 (Gateway errors) are always retried.
8546
8547 This is mainly useful if you are in a complex cache hierarchy to
8548 work around access control errors.
8549
8550 NOTE: This retry will attempt to find another working destination.
8551 Which is different from the server which just failed.
8552DOC_END
8553
8554NAME: as_whois_server
8555TYPE: string
8556LOC: Config.as_whois_server
8557DEFAULT: whois.ra.net
8558DOC_START
8559 WHOIS server to query for AS numbers. NOTE: AS numbers are
8560 queried only when Squid starts up, not for every request.
8561DOC_END
8562
8563NAME: offline_mode
8564TYPE: onoff
8565LOC: Config.onoff.offline
8566DEFAULT: off
8567DOC_START
8568 Enable this option and Squid will never try to validate cached
8569 objects.
8570DOC_END
8571
8572NAME: uri_whitespace
8573TYPE: uri_whitespace
8574LOC: Config.uri_whitespace
8575DEFAULT: strip
8576DOC_START
8577 What to do with requests that have whitespace characters in the
8578 URI. Options:
8579
8580 strip: The whitespace characters are stripped out of the URL.
8581 This is the behavior recommended by RFC2396 and RFC3986
8582 for tolerant handling of generic URI.
8583 NOTE: This is one difference between generic URI and HTTP URLs.
8584
8585 deny: The request is denied. The user receives an "Invalid
8586 Request" message.
8587 This is the behaviour recommended by RFC2616 for safe
8588 handling of HTTP request URL.
8589
8590 allow: The request is allowed and the URI is not changed. The
8591 whitespace characters remain in the URI. Note the
8592 whitespace is passed to redirector processes if they
8593 are in use.
8594 Note this may be considered a violation of RFC2616
8595 request parsing where whitespace is prohibited in the
8596 URL field.
8597
8598 encode: The request is allowed and the whitespace characters are
8599 encoded according to RFC1738.
8600
8601 chop: The request is allowed and the URI is chopped at the
8602 first whitespace.
8603
8604
8605 NOTE the current Squid implementation of encode and chop violates
8606 RFC2616 by not using a 301 redirect after altering the URL.
8607DOC_END
8608
8609NAME: chroot
8610TYPE: string
8611LOC: Config.chroot_dir
8612DEFAULT: none
8613DOC_START
8614 Specifies a directory where Squid should do a chroot() while
8615 initializing. This also causes Squid to fully drop root
8616 privileges after initializing. This means, for example, if you
8617 use a HTTP port less than 1024 and try to reconfigure, you may
8618 get an error saying that Squid can not open the port.
8619DOC_END
8620
8621NAME: balance_on_multiple_ip
8622TYPE: onoff
8623LOC: Config.onoff.balance_on_multiple_ip
8624DEFAULT: off
8625DOC_START
8626 Modern IP resolvers in squid sort lookup results by preferred access.
8627 By default squid will use these IP in order and only rotates to
8628 the next listed when the most preffered fails.
8629
8630 Some load balancing servers based on round robin DNS have been
8631 found not to preserve user session state across requests
8632 to different IP addresses.
8633
8634 Enabling this directive Squid rotates IP's per request.
8635DOC_END
8636
8637NAME: pipeline_prefetch
8638TYPE: onoff
8639LOC: Config.onoff.pipeline_prefetch
8640DEFAULT: off
8641DOC_START
8642 To boost the performance of pipelined requests to closer
8643 match that of a non-proxied environment Squid can try to fetch
8644 up to two requests in parallel from a pipeline.
8645
8646 Defaults to off for bandwidth management and access logging
8647 reasons.
8648
8649 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
8650DOC_END
8651
8652NAME: high_response_time_warning
8653TYPE: int
8654COMMENT: (msec)
8655LOC: Config.warnings.high_rptm
8656DEFAULT: 0
8657DEFAULT_DOC: disabled.
8658DOC_START
8659 If the one-minute median response time exceeds this value,
8660 Squid prints a WARNING with debug level 0 to get the
8661 administrators attention. The value is in milliseconds.
8662DOC_END
8663
8664NAME: high_page_fault_warning
8665TYPE: int
8666LOC: Config.warnings.high_pf
8667DEFAULT: 0
8668DEFAULT_DOC: disabled.
8669DOC_START
8670 If the one-minute average page fault rate exceeds this
8671 value, Squid prints a WARNING with debug level 0 to get
8672 the administrators attention. The value is in page faults
8673 per second.
8674DOC_END
8675
8676NAME: high_memory_warning
8677TYPE: b_size_t
8678LOC: Config.warnings.high_memory
8679DEFAULT: 0 KB
8680DEFAULT_DOC: disabled.
8681DOC_START
8682 If the memory usage (as determined by mallinfo) exceeds
8683 this amount, Squid prints a WARNING with debug level 0 to get
8684 the administrators attention.
8685DOC_END
8686
8687NAME: sleep_after_fork
8688COMMENT: (microseconds)
8689TYPE: int
8690LOC: Config.sleep_after_fork
8691DEFAULT: 0
8692DOC_START
8693 When this is set to a non-zero value, the main Squid process
8694 sleeps the specified number of microseconds after a fork()
8695 system call. This sleep may help the situation where your
8696 system reports fork() failures due to lack of (virtual)
8697 memory. Note, however, if you have a lot of child
8698 processes, these sleep delays will add up and your
8699 Squid will not service requests for some amount of time
8700 until all the child processes have been started.
8701 On Windows value less then 1000 (1 milliseconds) are
8702 rounded to 1000.
8703DOC_END
8704
8705NAME: windows_ipaddrchangemonitor
8706IFDEF: _SQUID_WINDOWS_
8707COMMENT: on|off
8708TYPE: onoff
8709DEFAULT: on
8710LOC: Config.onoff.WIN32_IpAddrChangeMonitor
8711DOC_START
8712 On Windows Squid by default will monitor IP address changes and will
8713 reconfigure itself after any detected event. This is very useful for
8714 proxies connected to internet with dial-up interfaces.
8715 In some cases (a Proxy server acting as VPN gateway is one) it could be
8716 desiderable to disable this behaviour setting this to 'off'.
8717 Note: after changing this, Squid service must be restarted.
8718DOC_END
8719
8720NAME: eui_lookup
8721TYPE: onoff
8722IFDEF: USE_SQUID_EUI
8723DEFAULT: on
8724LOC: Eui::TheConfig.euiLookup
8725DOC_START
8726 Whether to lookup the EUI or MAC address of a connected client.
8727DOC_END
8728
8729NAME: max_filedescriptors max_filedesc
8730TYPE: int
8731DEFAULT: 0
8732DEFAULT_DOC: Use operating system limits set by ulimit.
8733LOC: Config.max_filedescriptors
8734DOC_START
8735 Reduce the maximum number of filedescriptors supported below
8736 the usual operating system defaults.
8737
8738 Remove from squid.conf to inherit the current ulimit setting.
8739
8740 Note: Changing this requires a restart of Squid. Also
8741 not all I/O types supports large values (eg on Windows).
8742DOC_END
8743
8744NAME: workers
8745TYPE: int
8746LOC: Config.workers
8747DEFAULT: 1
8748DEFAULT_DOC: SMP support disabled.
8749DOC_START
8750 Number of main Squid processes or "workers" to fork and maintain.
8751 0: "no daemon" mode, like running "squid -N ..."
8752 1: "no SMP" mode, start one main Squid process daemon (default)
8753 N: start N main Squid process daemons (i.e., SMP mode)
8754
8755 In SMP mode, each worker does nearly all what a single Squid daemon
8756 does (e.g., listen on http_port and forward HTTP requests).
8757DOC_END
8758
8759NAME: cpu_affinity_map
8760TYPE: CpuAffinityMap
8761LOC: Config.cpuAffinityMap
8762DEFAULT: none
8763DEFAULT_DOC: Let operating system decide.
8764DOC_START
8765 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
8766
8767 Sets 1:1 mapping between Squid processes and CPU cores. For example,
8768
8769 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
8770
8771 affects processes 1 through 4 only and places them on the first
8772 four even cores, starting with core #1.
8773
8774 CPU cores are numbered starting from 1. Requires support for
8775 sched_getaffinity(2) and sched_setaffinity(2) system calls.
8776
8777 Multiple cpu_affinity_map options are merged.
8778
8779 See also: workers
8780DOC_END
8781
8782EOF