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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
29 COMMENT_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
51 COMMENT_END
52
53 COMMENT_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.
105 COMMENT_END
106
107 # Options Removed in 3.2
108 NAME: ignore_expect_100
109 TYPE: obsolete
110 DOC_START
111 Remove this line. The HTTP/1.1 feature is now fully supported by default.
112 DOC_END
113
114 NAME: dns_v4_fallback
115 TYPE: obsolete
116 DOC_START
117 Remove this line.
118 DOC_END
119
120 NAME: ftp_list_width
121 TYPE: obsolete
122 DOC_START
123 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
124 DOC_END
125
126 NAME: url_rewrite_concurrency
127 TYPE: obsolete
128 DOC_START
129 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
130 DOC_END
131
132 # Options Removed in 3.1
133 NAME: dns_testnames
134 TYPE: obsolete
135 DOC_START
136 Remove this line. DNS is no longer tested on startup.
137 DOC_END
138
139 NAME: extension_methods
140 TYPE: obsolete
141 DOC_START
142 Remove this line. All valid methods for HTTP are accepted by default.
143 DOC_END
144
145 # 2.7 Options Removed/Replaced in 3.1
146 NAME: incoming_rate
147 TYPE: obsolete
148 DOC_NONE
149
150 NAME: server_http11
151 TYPE: obsolete
152 DOC_START
153 Remove this line. HTTP/1.1 is supported by default.
154 DOC_END
155
156 NAME: upgrade_http0.9
157 TYPE: obsolete
158 DOC_START
159 Remove this line. ICY/1.0 streaming protocol is supported by default.
160 DOC_END
161
162 NAME: zph_local zph_mode zph_option zph_parent zph_sibling
163 TYPE: obsolete
164 DOC_START
165 Alter these entries. Use the qos_flows directive instead.
166 DOC_END
167
168 # Options Removed in 3.0
169 NAME: header_access
170 TYPE: obsolete
171 DOC_START
172 Since squid-3.0 replace with request_header_access or reply_header_access
173 depending on whether you wish to match client requests or server replies.
174 DOC_END
175
176 NAME: httpd_accel_no_pmtu_disc
177 TYPE: obsolete
178 DOC_START
179 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
180 DOC_END
181
182 COMMENT_START
183 OPTIONS FOR AUTHENTICATION
184 -----------------------------------------------------------------------------
185 COMMENT_END
186
187 NAME: auth_param
188 TYPE: authparam
189 IFDEF: USE_AUTH
190 LOC: Auth::TheConfig
191 DEFAULT: none
192 DOC_START
193 This is used to define parameters for the various authentication
194 schemes supported by Squid.
195
196 format: auth_param scheme parameter [setting]
197
198 The order in which authentication schemes are presented to the client is
199 dependent on the order the scheme first appears in config file. IE
200 has a bug (it's not RFC 2617 compliant) in that it will use the basic
201 scheme if basic is the first entry presented, even if more secure
202 schemes are presented. For now use the order in the recommended
203 settings section below. If other browsers have difficulties (don't
204 recognize the schemes offered even if you are using basic) either
205 put basic first, or disable the other schemes (by commenting out their
206 program entry).
207
208 Once an authentication scheme is fully configured, it can only be
209 shutdown by shutting squid down and restarting. Changes can be made on
210 the fly and activated with a reconfigure. I.E. You can change to a
211 different helper, but not unconfigure the helper completely.
212
213 Please note that while this directive defines how Squid processes
214 authentication it does not automatically activate authentication.
215 To use authentication you must in addition make use of ACLs based
216 on login name in http_access (proxy_auth, proxy_auth_regex or
217 external with %LOGIN used in the format tag). The browser will be
218 challenged for authentication on the first such acl encountered
219 in http_access processing and will also be re-challenged for new
220 login credentials if the request is being denied by a proxy_auth
221 type acl.
222
223 WARNING: authentication can't be used in a transparently intercepting
224 proxy as the client then thinks it is talking to an origin server and
225 not the proxy. This is a limitation of bending the TCP/IP protocol to
226 transparently intercepting port 80, not a limitation in Squid.
227 Ports flagged 'transparent', 'intercept', or 'tproxy' have
228 authentication disabled.
229
230 === Parameters for the basic scheme follow. ===
231
232 "program" cmdline
233 Specify the command for the external authenticator. Such a program
234 reads a line containing "username password" and replies "OK" or
235 "ERR" in an endless loop. "ERR" responses may optionally be followed
236 by a error description available as %m in the returned error page.
237 If you use an authenticator, make sure you have 1 acl of type
238 proxy_auth.
239
240 By default, the basic authentication scheme is not used unless a
241 program is specified.
242
243 If you want to use the traditional NCSA proxy authentication, set
244 this line to something like
245
246 auth_param basic program @DEFAULT_PREFIX@/libexec/ncsa_auth @DEFAULT_PREFIX@/etc/passwd
247
248 "utf8" on|off
249 HTTP uses iso-latin-1 as characterset, while some authentication
250 backends such as LDAP expects UTF-8. If this is set to on Squid will
251 translate the HTTP iso-latin-1 charset to UTF-8 before sending the
252 username & password to the helper.
253
254 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
255 The maximum number of authenticator processes to spawn. If you start too few
256 Squid will have to wait for them to process a backlog of credential
257 verifications, slowing it down. When password verifications are
258 done via a (slow) network you are likely to need lots of
259 authenticator processes.
260
261 The startup= and idle= options permit some skew in the exact amount
262 run. A minimum of startup=N will begin during startup and reconfigure.
263 Squid will start more in groups of up to idle=N in an attempt to meet
264 traffic needs and to keep idle=N free above those traffic needs up to
265 the maximum.
266
267 The concurrency= option sets the number of concurrent requests the
268 helper can process. The default of 0 is used for helpers who only
269 supports one request at a time. Setting this to a number greater than
270 0 changes the protocol used to include a channel number first on the
271 request/response line, allowing multiple requests to be sent to the
272 same helper in parallell without wating for the response.
273 Must not be set unless it's known the helper supports this.
274
275 auth_param basic children 20 startup=0 idle=1
276
277 "realm" realmstring
278 Specifies the realm name which is to be reported to the
279 client for the basic proxy authentication scheme (part of
280 the text the user will see when prompted their username and
281 password). There is no default.
282 auth_param basic realm Squid proxy-caching web server
283
284 "credentialsttl" timetolive
285 Specifies how long squid assumes an externally validated
286 username:password pair is valid for - in other words how
287 often the helper program is called for that user. Set this
288 low to force revalidation with short lived passwords. Note
289 setting this high does not impact your susceptibility
290 to replay attacks unless you are using an one-time password
291 system (such as SecureID). If you are using such a system,
292 you will be vulnerable to replay attacks unless you also
293 use the max_user_ip ACL in an http_access rule.
294
295 "casesensitive" on|off
296 Specifies if usernames are case sensitive. Most user databases are
297 case insensitive allowing the same username to be spelled using both
298 lower and upper case letters, but some are case sensitive. This
299 makes a big difference for user_max_ip ACL processing and similar.
300 auth_param basic casesensitive off
301
302 === Parameters for the digest scheme follow ===
303
304 "program" cmdline
305 Specify the command for the external authenticator. Such
306 a program reads a line containing "username":"realm" and
307 replies with the appropriate H(A1) value hex encoded or
308 ERR if the user (or his H(A1) hash) does not exists.
309 See rfc 2616 for the definition of H(A1).
310 "ERR" responses may optionally be followed by a error description
311 available as %m in the returned error page.
312
313 By default, the digest authentication scheme is not used unless a
314 program is specified.
315
316 If you want to use a digest authenticator, set this line to
317 something like
318
319 auth_param digest program @DEFAULT_PREFIX@/bin/digest_pw_auth @DEFAULT_PREFIX@/etc/digpass
320
321 "utf8" on|off
322 HTTP uses iso-latin-1 as characterset, while some authentication
323 backends such as LDAP expects UTF-8. If this is set to on Squid will
324 translate the HTTP iso-latin-1 charset to UTF-8 before sending the
325 username & password to the helper.
326
327 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
328 The maximum number of authenticator processes to spawn (default 5).
329 If you start too few Squid will have to wait for them to
330 process a backlog of H(A1) calculations, slowing it down.
331 When the H(A1) calculations are done via a (slow) network
332 you are likely to need lots of authenticator processes.
333
334 The startup= and idle= options permit some skew in the exact amount
335 run. A minimum of startup=N will begin during startup and reconfigure.
336 Squid will start more in groups of up to idle=N in an attempt to meet
337 traffic needs and to keep idle=N free above those traffic needs up to
338 the maximum.
339
340 The concurrency= option sets the number of concurrent requests the
341 helper can process. The default of 0 is used for helpers who only
342 supports one request at a time. Setting this to a number greater than
343 0 changes the protocol used to include a channel number first on the
344 request/response line, allowing multiple requests to be sent to the
345 same helper in parallell without wating for the response.
346 Must not be set unless it's known the helper supports this.
347
348 auth_param digest children 20 startup=0 idle=1
349
350 "realm" realmstring
351 Specifies the realm name which is to be reported to the
352 client for the digest proxy authentication scheme (part of
353 the text the user will see when prompted their username and
354 password). There is no default.
355 auth_param digest realm Squid proxy-caching web server
356
357 "nonce_garbage_interval" timeinterval
358 Specifies the interval that nonces that have been issued
359 to client_agent's are checked for validity.
360
361 "nonce_max_duration" timeinterval
362 Specifies the maximum length of time a given nonce will be
363 valid for.
364
365 "nonce_max_count" number
366 Specifies the maximum number of times a given nonce can be
367 used.
368
369 "nonce_strictness" on|off
370 Determines if squid requires strict increment-by-1 behavior
371 for nonce counts, or just incrementing (off - for use when
372 useragents generate nonce counts that occasionally miss 1
373 (ie, 1,2,4,6)). Default off.
374
375 "check_nonce_count" on|off
376 This directive if set to off can disable the nonce count check
377 completely to work around buggy digest qop implementations in
378 certain mainstream browser versions. Default on to check the
379 nonce count to protect from authentication replay attacks.
380
381 "post_workaround" on|off
382 This is a workaround to certain buggy browsers who sends
383 an incorrect request digest in POST requests when reusing
384 the same nonce as acquired earlier on a GET request.
385
386 === NTLM scheme options follow ===
387
388 "program" cmdline
389 Specify the command for the external NTLM authenticator.
390 Such a program reads exchanged NTLMSSP packets with
391 the browser via Squid until authentication is completed.
392 If you use an NTLM authenticator, make sure you have 1 acl
393 of type proxy_auth. By default, the NTLM authenticator_program
394 is not used.
395
396 auth_param ntlm program @DEFAULT_PREFIX@/bin/ntlm_auth
397
398 "children" numberofchildren [startup=N] [idle=N]
399 The maximum number of authenticator processes to spawn (default 5).
400 If you start too few Squid will have to wait for them to
401 process a backlog of credential verifications, slowing it
402 down. When credential verifications are done via a (slow)
403 network you are likely to need lots of authenticator
404 processes.
405
406 The startup= and idle= options permit some skew in the exact amount
407 run. A minimum of startup=N will begin during startup and reconfigure.
408 Squid will start more in groups of up to idle=N in an attempt to meet
409 traffic needs and to keep idle=N free above those traffic needs up to
410 the maximum.
411
412 auth_param ntlm children 20 startup=0 idle=1
413
414 "keep_alive" on|off
415 If you experience problems with PUT/POST requests when using the
416 Negotiate authentication scheme then you can try setting this to
417 off. This will cause Squid to forcibly close the connection on
418 the initial requests where the browser asks which schemes are
419 supported by the proxy.
420
421 auth_param ntlm keep_alive on
422
423 === Options for configuring the NEGOTIATE auth-scheme follow ===
424
425 "program" cmdline
426 Specify the command for the external Negotiate authenticator.
427 This protocol is used in Microsoft Active-Directory enabled setups with
428 the Microsoft Internet Explorer or Mozilla Firefox browsers.
429 Its main purpose is to exchange credentials with the Squid proxy
430 using the Kerberos mechanisms.
431 If you use a Negotiate authenticator, make sure you have at least
432 one acl of type proxy_auth active. By default, the negotiate
433 authenticator_program is not used.
434 The only supported program for this role is the ntlm_auth
435 program distributed as part of Samba, version 4 or later.
436
437 auth_param negotiate program @DEFAULT_PREFIX@/bin/ntlm_auth --helper-protocol=gss-spnego
438
439 "children" numberofchildren [startup=N] [idle=N]
440 The maximum number of authenticator processes to spawn (default 5).
441 If you start too few Squid will have to wait for them to
442 process a backlog of credential verifications, slowing it
443 down. When crendential verifications are done via a (slow)
444 network you are likely to need lots of authenticator
445 processes.
446
447 The startup= and idle= options permit some skew in the exact amount
448 run. A minimum of startup=N will begin during startup and reconfigure.
449 Squid will start more in groups of up to idle=N in an attempt to meet
450 traffic needs and to keep idle=N free above those traffic needs up to
451 the maximum.
452
453 auth_param negotiate children 20 startup=0 idle=1
454
455 "keep_alive" on|off
456 If you experience problems with PUT/POST requests when using the
457 Negotiate authentication scheme then you can try setting this to
458 off. This will cause Squid to forcibly close the connection on
459 the initial requests where the browser asks which schemes are
460 supported by the proxy.
461
462 auth_param negotiate keep_alive on
463
464
465 Examples:
466
467 #Recommended minimum configuration per scheme:
468 #auth_param negotiate program <uncomment and complete this line to activate>
469 #auth_param negotiate children 20 startup=0 idle=1
470 #auth_param negotiate keep_alive on
471 #
472 #auth_param ntlm program <uncomment and complete this line to activate>
473 #auth_param ntlm children 20 startup=0 idle=1
474 #auth_param ntlm keep_alive on
475 #
476 #auth_param digest program <uncomment and complete this line>
477 #auth_param digest children 20 startup=0 idle=1
478 #auth_param digest realm Squid proxy-caching web server
479 #auth_param digest nonce_garbage_interval 5 minutes
480 #auth_param digest nonce_max_duration 30 minutes
481 #auth_param digest nonce_max_count 50
482 #
483 #auth_param basic program <uncomment and complete this line>
484 #auth_param basic children 5 startup=5 idle=1
485 #auth_param basic realm Squid proxy-caching web server
486 #auth_param basic credentialsttl 2 hours
487 DOC_END
488
489 NAME: authenticate_cache_garbage_interval
490 TYPE: time_t
491 DEFAULT: 1 hour
492 LOC: Config.authenticateGCInterval
493 DOC_START
494 The time period between garbage collection across the username cache.
495 This is a tradeoff between memory utilization (long intervals - say
496 2 days) and CPU (short intervals - say 1 minute). Only change if you
497 have good reason to.
498 DOC_END
499
500 NAME: authenticate_ttl
501 TYPE: time_t
502 DEFAULT: 1 hour
503 LOC: Config.authenticateTTL
504 DOC_START
505 The time a user & their credentials stay in the logged in
506 user cache since their last request. When the garbage
507 interval passes, all user credentials that have passed their
508 TTL are removed from memory.
509 DOC_END
510
511 NAME: authenticate_ip_ttl
512 TYPE: time_t
513 LOC: Config.authenticateIpTTL
514 DEFAULT: 0 seconds
515 DOC_START
516 If you use proxy authentication and the 'max_user_ip' ACL,
517 this directive controls how long Squid remembers the IP
518 addresses associated with each user. Use a small value
519 (e.g., 60 seconds) if your users might change addresses
520 quickly, as is the case with dialups. You might be safe
521 using a larger value (e.g., 2 hours) in a corporate LAN
522 environment with relatively static address assignments.
523 DOC_END
524
525 COMMENT_START
526 ACCESS CONTROLS
527 -----------------------------------------------------------------------------
528 COMMENT_END
529
530 NAME: external_acl_type
531 TYPE: externalAclHelper
532 LOC: Config.externalAclHelperList
533 DEFAULT: none
534 DOC_START
535 This option defines external acl classes using a helper program
536 to look up the status
537
538 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
539
540 Options:
541
542 ttl=n TTL in seconds for cached results (defaults to 3600
543 for 1 hour)
544 negative_ttl=n
545 TTL for cached negative lookups (default same
546 as ttl)
547 children-max=n
548 Maximum number of acl helper processes spawned to service
549 external acl lookups of this type. (default 20)
550 children-startup=n
551 Minimum number of acl helper processes to spawn during
552 startup and reconfigure to service external acl lookups
553 of this type. (default 0)
554 children-idle=n
555 Number of acl helper processes to keep ahead of traffic
556 loads. Squid will spawn this many at once whenever load
557 rises above the capabilities of existing processes.
558 Up to the value of children-max. (default 1)
559 concurrency=n concurrency level per process. Only used with helpers
560 capable of processing more than one query at a time.
561 cache=n limit the result cache size, default is unbounded.
562 grace=n Percentage remaining of TTL where a refresh of a
563 cached entry should be initiated without needing to
564 wait for a new reply. (default is for no grace period)
565 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
566 ipv4 / ipv6 IP protocol used to communicate with this helper.
567 The default is to auto-detect IPv6 and use it when available.
568
569 FORMAT specifications
570
571 %LOGIN Authenticated user login name
572 %EXT_USER Username from previous external acl
573 %EXT_LOG Log details from previous external acl
574 %EXT_TAG Tag from previous external acl
575 %IDENT Ident user name
576 %SRC Client IP
577 %SRCPORT Client source port
578 %URI Requested URI
579 %DST Requested host
580 %PROTO Requested protocol
581 %PORT Requested port
582 %PATH Requested URL path
583 %METHOD Request method
584 %MYADDR Squid interface address
585 %MYPORT Squid http_port number
586 %PATH Requested URL-path (including query-string if any)
587 %USER_CERT SSL User certificate in PEM format
588 %USER_CERTCHAIN SSL User certificate chain in PEM format
589 %USER_CERT_xx SSL User certificate subject attribute xx
590 %USER_CA_xx SSL User certificate issuer attribute xx
591
592 %>{Header} HTTP request header "Header"
593 %>{Hdr:member}
594 HTTP request header "Hdr" list member "member"
595 %>{Hdr:;member}
596 HTTP request header list member using ; as
597 list separator. ; can be any non-alphanumeric
598 character.
599
600 %<{Header} HTTP reply header "Header"
601 %<{Hdr:member}
602 HTTP reply header "Hdr" list member "member"
603 %<{Hdr:;member}
604 HTTP reply header list member using ; as
605 list separator. ; can be any non-alphanumeric
606 character.
607
608 %% The percent sign. Useful for helpers which need
609 an unchanging input format.
610
611 In addition to the above, any string specified in the referencing
612 acl will also be included in the helper request line, after the
613 specified formats (see the "acl external" directive)
614
615 The helper receives lines per the above format specification,
616 and returns lines starting with OK or ERR indicating the validity
617 of the request and optionally followed by additional keywords with
618 more details.
619
620 General result syntax:
621
622 OK/ERR keyword=value ...
623
624 Defined keywords:
625
626 user= The users name (login)
627 password= The users password (for login= cache_peer option)
628 message= Message describing the reason. Available as %o
629 in error pages
630 tag= Apply a tag to a request (for both ERR and OK results)
631 Only sets a tag, does not alter existing tags.
632 log= String to be logged in access.log. Available as
633 %ea in logformat specifications
634
635 If protocol=3.0 (the default) then URL escaping is used to protect
636 each value in both requests and responses.
637
638 If using protocol=2.5 then all values need to be enclosed in quotes
639 if they may contain whitespace, or the whitespace escaped using \.
640 And quotes or \ characters within the keyword value must be \ escaped.
641
642 When using the concurrency= option the protocol is changed by
643 introducing a query channel tag infront of the request/response.
644 The query channel tag is a number between 0 and concurrency-1.
645 DOC_END
646
647 NAME: acl
648 TYPE: acl
649 LOC: Config.aclList
650 IFDEF USE_SSL
651 DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
652 DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
653 DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
654 DEFAULT: 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
655 DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
656 ENDIF
657 DEFAULT: all src all
658 DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
659 DEFAULT: localhost src 127.0.0.1/32 ::1
660 DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
661 DEFAULT_DOC: ACLs all, manager, localhost, and to_localhost are predefined.
662 DOC_START
663 Defining an Access List
664
665 Every access list definition must begin with an aclname and acltype,
666 followed by either type-specific arguments or a quoted filename that
667 they are read from.
668
669 acl aclname acltype argument ...
670 acl aclname acltype "file" ...
671
672 When using "file", the file should contain one item per line.
673
674 By default, regular expressions are CASE-SENSITIVE.
675 To make them case-insensitive, use the -i option. To return case-sensitive
676 use the +i option between patterns, or make a new ACL line without -i.
677
678 Some acl types require suspending the current request in order
679 to access some external data source.
680 Those which do are marked with the tag [slow], those which
681 don't are marked as [fast].
682 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
683 for further information
684
685 ***** ACL TYPES AVAILABLE *****
686
687 acl aclname src ip-address/mask ... # clients IP address [fast]
688 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
689 acl aclname dst ip-address/mask ... # URL host's IP address [slow]
690 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
691
692 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
693 # The arp ACL requires the special configure option --enable-arp-acl.
694 # Furthermore, the ARP ACL code is not portable to all operating systems.
695 # It works on Linux, Solaris, Windows, FreeBSD, and some
696 # other *BSD variants.
697 # [fast]
698 #
699 # NOTE: Squid can only determine the MAC address for clients that are on
700 # the same subnet. If the client is on a different subnet,
701 # then Squid cannot find out its MAC address.
702
703 acl aclname srcdomain .foo.com ...
704 # reverse lookup, from client IP [slow]
705 acl aclname dstdomain .foo.com ...
706 # Destination server from URL [fast]
707 acl aclname srcdom_regex [-i] \.foo\.com ...
708 # regex matching client name [slow]
709 acl aclname dstdom_regex [-i] \.foo\.com ...
710 # regex matching server [fast]
711 #
712 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
713 # based URL is used and no match is found. The name "none" is used
714 # if the reverse lookup fails.
715
716 acl aclname src_as number ...
717 acl aclname dst_as number ...
718 # [fast]
719 # Except for access control, AS numbers can be used for
720 # routing of requests to specific caches. Here's an
721 # example for routing all requests for AS#1241 and only
722 # those to mycache.mydomain.net:
723 # acl asexample dst_as 1241
724 # cache_peer_access mycache.mydomain.net allow asexample
725 # cache_peer_access mycache_mydomain.net deny all
726
727 acl aclname peername myPeer ...
728 # [fast]
729 # match against a named cache_peer entry
730 # set unique name= on cache_peer lines for reliable use.
731
732 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
733 # [fast]
734 # day-abbrevs:
735 # S - Sunday
736 # M - Monday
737 # T - Tuesday
738 # W - Wednesday
739 # H - Thursday
740 # F - Friday
741 # A - Saturday
742 # h1:m1 must be less than h2:m2
743
744 acl aclname url_regex [-i] ^http:// ...
745 # regex matching on whole URL [fast]
746 acl aclname urlpath_regex [-i] \.gif$ ...
747 # regex matching on URL path [fast]
748
749 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
750 # ranges are alloed
751 acl aclname localport 3128 ... # TCP port the client connected to [fast]
752 # NP: for interception mode this is usually '80'
753
754 acl aclname myportname 3128 ... # http(s)_port name [fast]
755
756 acl aclname proto HTTP FTP ... # request protocol [fast]
757
758 acl aclname method GET POST ... # HTTP request method [fast]
759
760 acl aclname http_status 200 301 500- 400-403 ...
761 # status code in reply [fast]
762
763 acl aclname browser [-i] regexp ...
764 # pattern match on User-Agent header (see also req_header below) [fast]
765
766 acl aclname referer_regex [-i] regexp ...
767 # pattern match on Referer header [fast]
768 # Referer is highly unreliable, so use with care
769
770 acl aclname ident username ...
771 acl aclname ident_regex [-i] pattern ...
772 # string match on ident output [slow]
773 # use REQUIRED to accept any non-null ident.
774
775 acl aclname proxy_auth [-i] username ...
776 acl aclname proxy_auth_regex [-i] pattern ...
777 # perform http authentication challenge to the client and match against
778 # supplied credentials [slow]
779 #
780 # takes a list of allowed usernames.
781 # use REQUIRED to accept any valid username.
782 #
783 # Will use proxy authentication in forward-proxy scenarios, and plain
784 # http authenticaiton in reverse-proxy scenarios
785 #
786 # NOTE: when a Proxy-Authentication header is sent but it is not
787 # needed during ACL checking the username is NOT logged
788 # in access.log.
789 #
790 # NOTE: proxy_auth requires a EXTERNAL authentication program
791 # to check username/password combinations (see
792 # auth_param directive).
793 #
794 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
795 # as the browser needs to be configured for using a proxy in order
796 # to respond to proxy authentication.
797
798 acl aclname snmp_community string ...
799 # A community string to limit access to your SNMP Agent [fast]
800 # Example:
801 #
802 # acl snmppublic snmp_community public
803
804 acl aclname maxconn number
805 # This will be matched when the client's IP address has
806 # more than <number> TCP connections established. [fast]
807 # NOTE: This only measures direct TCP links so X-Forwarded-For
808 # indirect clients are not counted.
809
810 acl aclname max_user_ip [-s] number
811 # This will be matched when the user attempts to log in from more
812 # than <number> different ip addresses. The authenticate_ip_ttl
813 # parameter controls the timeout on the ip entries. [fast]
814 # If -s is specified the limit is strict, denying browsing
815 # from any further IP addresses until the ttl has expired. Without
816 # -s Squid will just annoy the user by "randomly" denying requests.
817 # (the counter is reset each time the limit is reached and a
818 # request is denied)
819 # NOTE: in acceleration mode or where there is mesh of child proxies,
820 # clients may appear to come from multiple addresses if they are
821 # going through proxy farms, so a limit of 1 may cause user problems.
822
823 acl aclname random probability
824 # Pseudo-randomly match requests. Based on the probability given.
825 # Probability may be written as a decimal (0.333), fraction (1/3)
826 # or ratio of matches:non-matches (3:5).
827
828 acl aclname req_mime_type [-i] mime-type ...
829 # regex match against the mime type of the request generated
830 # by the client. Can be used to detect file upload or some
831 # types HTTP tunneling requests [fast]
832 # NOTE: This does NOT match the reply. You cannot use this
833 # to match the returned file type.
834
835 acl aclname req_header header-name [-i] any\.regex\.here
836 # regex match against any of the known request headers. May be
837 # thought of as a superset of "browser", "referer" and "mime-type"
838 # ACL [fast]
839
840 acl aclname rep_mime_type [-i] mime-type ...
841 # regex match against the mime type of the reply received by
842 # squid. Can be used to detect file download or some
843 # types HTTP tunneling requests. [fast]
844 # NOTE: This has no effect in http_access rules. It only has
845 # effect in rules that affect the reply data stream such as
846 # http_reply_access.
847
848 acl aclname rep_header header-name [-i] any\.regex\.here
849 # regex match against any of the known reply headers. May be
850 # thought of as a superset of "browser", "referer" and "mime-type"
851 # ACLs [fast]
852
853 acl aclname external class_name [arguments...]
854 # external ACL lookup via a helper class defined by the
855 # external_acl_type directive [slow]
856
857 acl aclname user_cert attribute values...
858 # match against attributes in a user SSL certificate
859 # attribute is one of DN/C/O/CN/L/ST [fast]
860
861 acl aclname ca_cert attribute values...
862 # match against attributes a users issuing CA SSL certificate
863 # attribute is one of DN/C/O/CN/L/ST [fast]
864
865 acl aclname ext_user username ...
866 acl aclname ext_user_regex [-i] pattern ...
867 # string match on username returned by external acl helper [slow]
868 # use REQUIRED to accept any non-null user name.
869
870 acl aclname tag tagvalue ...
871 # string match on tag returned by external acl helper [slow]
872
873 acl aclname hier_code codename ...
874 # string match against squid hierarchy code(s); [fast]
875 # e.g., DIRECT, PARENT_HIT, NONE, etc.
876 #
877 # NOTE: This has no effect in http_access rules. It only has
878 # effect in rules that affect the reply data stream such as
879 # http_reply_access.
880
881 IFDEF USE_SSL
882 acl aclname ssl_error errorname
883 # match against SSL certificate validation error [fast]
884 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt template file
885 # The user aditionaly can use as error name the following error name
886 # shortcuts:
887 # [ssl::]certHasExpired: certificate "not after" field is in the past
888 # [ssl::]certNotYetValid: certificate "not before" field is in the
889 # future
890 # [ssl::]certDomainMismatch: The certificate CN domain does not match
891 # connecting host name
892 # [ssl::]certUntrusted: The certificate is untrusted because of an
893 # error says that the certificate issuer is not trusted.
894 # [ssl::]certSelfSigned: The certificate is self signed
895 #
896 # The ssl::certHasExpired, ssl::certNotYetValid ssl::certDomainMismatch,
897 # ssl::certUntrusted and ssl::certSelfSigned also exists as predefined
898 # acl lists.
899 #
900 # NOTE: The ssl_error acl has effect only when used with
901 # sslproxy_cert_error, sslproxy_cert_sign and sslproxy_cert_adapt
902 # access lists.
903 ENDIF
904
905 Examples:
906 acl macaddress arp 09:00:2b:23:45:67
907 acl myexample dst_as 1241
908 acl password proxy_auth REQUIRED
909 acl fileupload req_mime_type -i ^multipart/form-data$
910 acl javascript rep_mime_type -i ^application/x-javascript$
911
912 NOCOMMENT_START
913 #
914 # Recommended minimum configuration:
915 #
916
917 # Example rule allowing access from your local networks.
918 # Adapt to list your (internal) IP networks from where browsing
919 # should be allowed
920 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
921 acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
922 acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
923 acl localnet src fc00::/7 # RFC 4193 local private network range
924 acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
925
926 acl SSL_ports port 443
927 acl Safe_ports port 80 # http
928 acl Safe_ports port 21 # ftp
929 acl Safe_ports port 443 # https
930 acl Safe_ports port 70 # gopher
931 acl Safe_ports port 210 # wais
932 acl Safe_ports port 1025-65535 # unregistered ports
933 acl Safe_ports port 280 # http-mgmt
934 acl Safe_ports port 488 # gss-http
935 acl Safe_ports port 591 # filemaker
936 acl Safe_ports port 777 # multiling http
937 acl CONNECT method CONNECT
938 NOCOMMENT_END
939 DOC_END
940
941 NAME: follow_x_forwarded_for
942 TYPE: acl_access
943 IFDEF: FOLLOW_X_FORWARDED_FOR
944 LOC: Config.accessList.followXFF
945 DEFAULT_IF_NONE: deny all
946 DOC_START
947 Allowing or Denying the X-Forwarded-For header to be followed to
948 find the original source of a request.
949
950 Requests may pass through a chain of several other proxies
951 before reaching us. The X-Forwarded-For header will contain a
952 comma-separated list of the IP addresses in the chain, with the
953 rightmost address being the most recent.
954
955 If a request reaches us from a source that is allowed by this
956 configuration item, then we consult the X-Forwarded-For header
957 to see where that host received the request from. If the
958 X-Forwarded-For header contains multiple addresses, we continue
959 backtracking until we reach an address for which we are not allowed
960 to follow the X-Forwarded-For header, or until we reach the first
961 address in the list. For the purpose of ACL used in the
962 follow_x_forwarded_for directive the src ACL type always matches
963 the address we are testing and srcdomain matches its rDNS.
964
965 The end result of this process is an IP address that we will
966 refer to as the indirect client address. This address may
967 be treated as the client address for access control, ICAP, delay
968 pools and logging, depending on the acl_uses_indirect_client,
969 icap_uses_indirect_client, delay_pool_uses_indirect_client,
970 log_uses_indirect_client and tproxy_uses_indirect_client options.
971
972 This clause only supports fast acl types.
973 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
974
975 SECURITY CONSIDERATIONS:
976
977 Any host for which we follow the X-Forwarded-For header
978 can place incorrect information in the header, and Squid
979 will use the incorrect information as if it were the
980 source address of the request. This may enable remote
981 hosts to bypass any access control restrictions that are
982 based on the client's source addresses.
983
984 For example:
985
986 acl localhost src 127.0.0.1
987 acl my_other_proxy srcdomain .proxy.example.com
988 follow_x_forwarded_for allow localhost
989 follow_x_forwarded_for allow my_other_proxy
990 DOC_END
991
992 NAME: acl_uses_indirect_client
993 COMMENT: on|off
994 TYPE: onoff
995 IFDEF: FOLLOW_X_FORWARDED_FOR
996 DEFAULT: on
997 LOC: Config.onoff.acl_uses_indirect_client
998 DOC_START
999 Controls whether the indirect client address
1000 (see follow_x_forwarded_for) is used instead of the
1001 direct client address in acl matching.
1002
1003 NOTE: maxconn ACL considers direct TCP links and indirect
1004 clients will always have zero. So no match.
1005 DOC_END
1006
1007 NAME: delay_pool_uses_indirect_client
1008 COMMENT: on|off
1009 TYPE: onoff
1010 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
1011 DEFAULT: on
1012 LOC: Config.onoff.delay_pool_uses_indirect_client
1013 DOC_START
1014 Controls whether the indirect client address
1015 (see follow_x_forwarded_for) is used instead of the
1016 direct client address in delay pools.
1017 DOC_END
1018
1019 NAME: log_uses_indirect_client
1020 COMMENT: on|off
1021 TYPE: onoff
1022 IFDEF: FOLLOW_X_FORWARDED_FOR
1023 DEFAULT: on
1024 LOC: Config.onoff.log_uses_indirect_client
1025 DOC_START
1026 Controls whether the indirect client address
1027 (see follow_x_forwarded_for) is used instead of the
1028 direct client address in the access log.
1029 DOC_END
1030
1031 NAME: tproxy_uses_indirect_client
1032 COMMENT: on|off
1033 TYPE: onoff
1034 IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
1035 DEFAULT: off
1036 LOC: Config.onoff.tproxy_uses_indirect_client
1037 DOC_START
1038 Controls whether the indirect client address
1039 (see follow_x_forwarded_for) is used instead of the
1040 direct client address when spoofing the outgoing client.
1041
1042 This has no effect on requests arriving in non-tproxy
1043 mode ports.
1044
1045 SECURITY WARNING: Usage of this option is dangerous
1046 and should not be used trivially. Correct configuration
1047 of follow_x_forewarded_for with a limited set of trusted
1048 sources is required to prevent abuse of your proxy.
1049 DOC_END
1050
1051 NAME: http_access
1052 TYPE: acl_access
1053 LOC: Config.accessList.http
1054 DEFAULT_IF_NONE: deny all
1055 DOC_START
1056 Allowing or Denying access based on defined access lists
1057
1058 Access to the HTTP port:
1059 http_access allow|deny [!]aclname ...
1060
1061 NOTE on default values:
1062
1063 If there are no "access" lines present, the default is to deny
1064 the request.
1065
1066 If none of the "access" lines cause a match, the default is the
1067 opposite of the last line in the list. If the last line was
1068 deny, the default is allow. Conversely, if the last line
1069 is allow, the default will be deny. For these reasons, it is a
1070 good idea to have an "deny all" entry at the end of your access
1071 lists to avoid potential confusion.
1072
1073 This clause supports both fast and slow acl types.
1074 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1075
1076 NOCOMMENT_START
1077
1078 #
1079 # Recommended minimum Access Permission configuration:
1080 #
1081 # Only allow cachemgr access from localhost
1082 http_access allow localhost manager
1083 http_access deny manager
1084
1085 # Deny requests to certain unsafe ports
1086 http_access deny !Safe_ports
1087
1088 # Deny CONNECT to other than secure SSL ports
1089 http_access deny CONNECT !SSL_ports
1090
1091 # We strongly recommend the following be uncommented to protect innocent
1092 # web applications running on the proxy server who think the only
1093 # one who can access services on "localhost" is a local user
1094 #http_access deny to_localhost
1095
1096 #
1097 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1098 #
1099
1100 # Example rule allowing access from your local networks.
1101 # Adapt localnet in the ACL section to list your (internal) IP networks
1102 # from where browsing should be allowed
1103 http_access allow localnet
1104 http_access allow localhost
1105
1106 # And finally deny all other access to this proxy
1107 http_access deny all
1108 NOCOMMENT_END
1109 DOC_END
1110
1111 NAME: adapted_http_access http_access2
1112 TYPE: acl_access
1113 LOC: Config.accessList.adapted_http
1114 DEFAULT: none
1115 DOC_START
1116 Allowing or Denying access based on defined access lists
1117
1118 Essentially identical to http_access, but runs after redirectors
1119 and ICAP/eCAP adaptation. Allowing access control based on their
1120 output.
1121
1122 If not set then only http_access is used.
1123 DOC_END
1124
1125 NAME: http_reply_access
1126 TYPE: acl_access
1127 LOC: Config.accessList.reply
1128 DEFAULT: none
1129 DOC_START
1130 Allow replies to client requests. This is complementary to http_access.
1131
1132 http_reply_access allow|deny [!] aclname ...
1133
1134 NOTE: if there are no access lines present, the default is to allow
1135 all replies
1136
1137 If none of the access lines cause a match the opposite of the
1138 last line will apply. Thus it is good practice to end the rules
1139 with an "allow all" or "deny all" entry.
1140
1141 This clause supports both fast and slow acl types.
1142 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1143 DOC_END
1144
1145 NAME: icp_access
1146 TYPE: acl_access
1147 LOC: Config.accessList.icp
1148 DEFAULT_IF_NONE: deny all
1149 DOC_START
1150 Allowing or Denying access to the ICP port based on defined
1151 access lists
1152
1153 icp_access allow|deny [!]aclname ...
1154
1155 See http_access for details
1156
1157 This clause only supports fast acl types.
1158 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1159
1160 # Allow ICP queries from local networks only
1161 #icp_access allow localnet
1162 #icp_access deny all
1163 DOC_END
1164
1165 NAME: htcp_access
1166 IFDEF: USE_HTCP
1167 TYPE: acl_access
1168 LOC: Config.accessList.htcp
1169 DEFAULT_IF_NONE: deny all
1170 DOC_START
1171 Allowing or Denying access to the HTCP port based on defined
1172 access lists
1173
1174 htcp_access allow|deny [!]aclname ...
1175
1176 See http_access for details
1177
1178 NOTE: The default if no htcp_access lines are present is to
1179 deny all traffic. This default may cause problems with peers
1180 using the htcp option.
1181
1182 This clause only supports fast acl types.
1183 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1184
1185 # Allow HTCP queries from local networks only
1186 #htcp_access allow localnet
1187 #htcp_access deny all
1188 DOC_END
1189
1190 NAME: htcp_clr_access
1191 IFDEF: USE_HTCP
1192 TYPE: acl_access
1193 LOC: Config.accessList.htcp_clr
1194 DEFAULT_IF_NONE: deny all
1195 DOC_START
1196 Allowing or Denying access to purge content using HTCP based
1197 on defined access lists
1198
1199 htcp_clr_access allow|deny [!]aclname ...
1200
1201 See http_access for details
1202
1203 This clause only supports fast acl types.
1204 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1205
1206 # Allow HTCP CLR requests from trusted peers
1207 acl htcp_clr_peer src 172.16.1.2
1208 htcp_clr_access allow htcp_clr_peer
1209 DOC_END
1210
1211 NAME: miss_access
1212 TYPE: acl_access
1213 LOC: Config.accessList.miss
1214 DEFAULT: none
1215 DOC_START
1216 Determins whether network access is permitted when satisfying a request.
1217
1218 For example;
1219 to force your neighbors to use you as a sibling instead of
1220 a parent.
1221
1222 acl localclients src 172.16.0.0/16
1223 miss_access allow localclients
1224 miss_access deny !localclients
1225
1226 This means only your local clients are allowed to fetch relayed/MISS
1227 replies from the network and all other clients can only fetch cached
1228 objects (HITs).
1229
1230
1231 The default for this setting allows all clients who passed the
1232 http_access rules to relay via this proxy.
1233
1234 This clause only supports fast acl types.
1235 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1236 DOC_END
1237
1238 NAME: ident_lookup_access
1239 TYPE: acl_access
1240 IFDEF: USE_IDENT
1241 DEFAULT_IF_NONE: deny all
1242 LOC: Ident::TheConfig.identLookup
1243 DOC_START
1244 A list of ACL elements which, if matched, cause an ident
1245 (RFC 931) lookup to be performed for this request. For
1246 example, you might choose to always perform ident lookups
1247 for your main multi-user Unix boxes, but not for your Macs
1248 and PCs. By default, ident lookups are not performed for
1249 any requests.
1250
1251 To enable ident lookups for specific client addresses, you
1252 can follow this example:
1253
1254 acl ident_aware_hosts src 198.168.1.0/24
1255 ident_lookup_access allow ident_aware_hosts
1256 ident_lookup_access deny all
1257
1258 Only src type ACL checks are fully supported. A srcdomain
1259 ACL might work at times, but it will not always provide
1260 the correct result.
1261
1262 This clause only supports fast acl types.
1263 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1264 DOC_END
1265
1266 NAME: reply_body_max_size
1267 COMMENT: size [acl acl...]
1268 TYPE: acl_b_size_t
1269 DEFAULT: none
1270 LOC: Config.ReplyBodySize
1271 DOC_START
1272 This option specifies the maximum size of a reply body. It can be
1273 used to prevent users from downloading very large files, such as
1274 MP3's and movies. When the reply headers are received, the
1275 reply_body_max_size lines are processed, and the first line where
1276 all (if any) listed ACLs are true is used as the maximum body size
1277 for this reply.
1278
1279 This size is checked twice. First when we get the reply headers,
1280 we check the content-length value. If the content length value exists
1281 and is larger than the allowed size, the request is denied and the
1282 user receives an error message that says "the request or reply
1283 is too large." If there is no content-length, and the reply
1284 size exceeds this limit, the client's connection is just closed
1285 and they will receive a partial reply.
1286
1287 WARNING: downstream caches probably can not detect a partial reply
1288 if there is no content-length header, so they will cache
1289 partial responses and give them out as hits. You should NOT
1290 use this option if you have downstream caches.
1291
1292 WARNING: A maximum size smaller than the size of squid's error messages
1293 will cause an infinite loop and crash squid. Ensure that the smallest
1294 non-zero value you use is greater that the maximum header size plus
1295 the size of your largest error page.
1296
1297 If you set this parameter none (the default), there will be
1298 no limit imposed.
1299
1300 Configuration Format is:
1301 reply_body_max_size SIZE UNITS [acl ...]
1302 ie.
1303 reply_body_max_size 10 MB
1304
1305 DOC_END
1306
1307 COMMENT_START
1308 NETWORK OPTIONS
1309 -----------------------------------------------------------------------------
1310 COMMENT_END
1311
1312 NAME: http_port ascii_port
1313 TYPE: http_port_list
1314 DEFAULT: none
1315 LOC: Config.Sockaddr.http
1316 DOC_START
1317 Usage: port [mode] [options]
1318 hostname:port [mode] [options]
1319 1.2.3.4:port [mode] [options]
1320
1321 The socket addresses where Squid will listen for HTTP client
1322 requests. You may specify multiple socket addresses.
1323 There are three forms: port alone, hostname with port, and
1324 IP address with port. If you specify a hostname or IP
1325 address, Squid binds the socket to that specific
1326 address. Most likely, you do not need to bind to a specific
1327 address, so you can use the port number alone.
1328
1329 If you are running Squid in accelerator mode, you
1330 probably want to listen on port 80 also, or instead.
1331
1332 The -a command line option may be used to specify additional
1333 port(s) where Squid listens for proxy request. Such ports will
1334 be plain proxy ports with no options.
1335
1336 You may specify multiple socket addresses on multiple lines.
1337
1338 Modes:
1339
1340 intercept Support for IP-Layer interception of
1341 outgoing requests without browser settings.
1342 NP: disables authentication and IPv6 on the port.
1343
1344 tproxy Support Linux TPROXY for spoofing outgoing
1345 connections using the client IP address.
1346 NP: disables authentication and maybe IPv6 on the port.
1347
1348 accel Accelerator / reverse proxy mode
1349
1350 ssl-bump Intercept each CONNECT request matching ssl_bump ACL,
1351 establish secure connection with the client and with
1352 the server, decrypt HTTP messages as they pass through
1353 Squid, and treat them as unencrypted HTTP messages,
1354 becoming the man-in-the-middle.
1355
1356 The ssl_bump option is required to fully enable
1357 the SslBump feature.
1358
1359 Omitting the mode flag causes default forward proxy mode to be used.
1360
1361
1362 Accelerator Mode Options:
1363
1364 defaultsite=domainname
1365 What to use for the Host: header if it is not present
1366 in a request. Determines what site (not origin server)
1367 accelerators should consider the default.
1368
1369 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1370
1371 protocol= Protocol to reconstruct accelerated requests with.
1372 Defaults to http for http_port and https for
1373 https_port
1374
1375 vport Virtual host port support. Using the http_port number
1376 instead of the port passed on Host: headers.
1377
1378 vport=NN Virtual host port support. Using the specified port
1379 number instead of the port passed on Host: headers.
1380
1381 act-as-origin
1382 Act as if this Squid is the origin server.
1383 This currently means generate new Date: and Expires:
1384 headers on HIT instead of adding Age:.
1385
1386 ignore-cc Ignore request Cache-Control headers.
1387
1388 WARNING: This option violates HTTP specifications if
1389 used in non-accelerator setups.
1390
1391 allow-direct Allow direct forwarding in accelerator mode. Normally
1392 accelerated requests are denied direct forwarding as if
1393 never_direct was used.
1394
1395 WARNING: this option opens accelerator mode to security
1396 vulnerabilities usually only affecting in interception
1397 mode. Make sure to protect forwarding with suitable
1398 http_access rules when using this.
1399
1400
1401 SSL Bump Mode Options:
1402 In addition to these options ssl-bump requires TLS/SSL options.
1403
1404 generate-host-certificates[=<on|off>]
1405 Dynamically create SSL server certificates for the
1406 destination hosts of bumped CONNECT requests.When
1407 enabled, the cert and key options are used to sign
1408 generated certificates. Otherwise generated
1409 certificate will be selfsigned.
1410 If there is a CA certificate lifetime of the generated
1411 certificate equals lifetime of the CA certificate. If
1412 generated certificate is selfsigned lifetime is three
1413 years.
1414 This option is enabled by default when ssl-bump is used.
1415 See the ssl-bump option above for more information.
1416
1417 dynamic_cert_mem_cache_size=SIZE
1418 Approximate total RAM size spent on cached generated
1419 certificates. If set to zero, caching is disabled. The
1420 default value is 4MB. An average XXX-bit certificate
1421 consumes about XXX bytes of RAM.
1422
1423 TLS / SSL Options:
1424
1425 cert= Path to SSL certificate (PEM format).
1426
1427 key= Path to SSL private key file (PEM format)
1428 if not specified, the certificate file is
1429 assumed to be a combined certificate and
1430 key file.
1431
1432 version= The version of SSL/TLS supported
1433 1 automatic (default)
1434 2 SSLv2 only
1435 3 SSLv3 only
1436 4 TLSv1 only
1437
1438 cipher= Colon separated list of supported ciphers.
1439 NOTE: some ciphers such as EDH ciphers depend on
1440 additional settings. If those settings are
1441 omitted the ciphers may be silently ignored
1442 by the OpenSSL library.
1443
1444 options= Various SSL implementation options. The most important
1445 being:
1446 NO_SSLv2 Disallow the use of SSLv2
1447 NO_SSLv3 Disallow the use of SSLv3
1448 NO_TLSv1 Disallow the use of TLSv1
1449 SINGLE_DH_USE Always create a new key when using
1450 temporary/ephemeral DH key exchanges
1451 ALL Enable various bug workarounds
1452 suggested as "harmless" by OpenSSL
1453 Be warned that this reduces SSL/TLS
1454 strength to some attacks.
1455 See OpenSSL SSL_CTX_set_options documentation for a
1456 complete list of options.
1457
1458 clientca= File containing the list of CAs to use when
1459 requesting a client certificate.
1460
1461 cafile= File containing additional CA certificates to
1462 use when verifying client certificates. If unset
1463 clientca will be used.
1464
1465 capath= Directory containing additional CA certificates
1466 and CRL lists to use when verifying client certificates.
1467
1468 crlfile= File of additional CRL lists to use when verifying
1469 the client certificate, in addition to CRLs stored in
1470 the capath. Implies VERIFY_CRL flag below.
1471
1472 dhparams= File containing DH parameters for temporary/ephemeral
1473 DH key exchanges. See OpenSSL documentation for details
1474 on how to create this file.
1475 WARNING: EDH ciphers will be silently disabled if this
1476 option is not set.
1477
1478 sslflags= Various flags modifying the use of SSL:
1479 DELAYED_AUTH
1480 Don't request client certificates
1481 immediately, but wait until acl processing
1482 requires a certificate (not yet implemented).
1483 NO_DEFAULT_CA
1484 Don't use the default CA lists built in
1485 to OpenSSL.
1486 NO_SESSION_REUSE
1487 Don't allow for session reuse. Each connection
1488 will result in a new SSL session.
1489 VERIFY_CRL
1490 Verify CRL lists when accepting client
1491 certificates.
1492 VERIFY_CRL_ALL
1493 Verify CRL lists for all certificates in the
1494 client certificate chain.
1495
1496 sslcontext= SSL session ID context identifier.
1497
1498 Other Options:
1499
1500 connection-auth[=on|off]
1501 use connection-auth=off to tell Squid to prevent
1502 forwarding Microsoft connection oriented authentication
1503 (NTLM, Negotiate and Kerberos)
1504
1505 disable-pmtu-discovery=
1506 Control Path-MTU discovery usage:
1507 off lets OS decide on what to do (default).
1508 transparent disable PMTU discovery when transparent
1509 support is enabled.
1510 always disable always PMTU discovery.
1511
1512 In many setups of transparently intercepting proxies
1513 Path-MTU discovery can not work on traffic towards the
1514 clients. This is the case when the intercepting device
1515 does not fully track connections and fails to forward
1516 ICMP must fragment messages to the cache server. If you
1517 have such setup and experience that certain clients
1518 sporadically hang or never complete requests set
1519 disable-pmtu-discovery option to 'transparent'.
1520
1521 name= Specifies a internal name for the port. Defaults to
1522 the port specification (port or addr:port)
1523
1524 tcpkeepalive[=idle,interval,timeout]
1525 Enable TCP keepalive probes of idle connections.
1526 In seconds; idle is the initial time before TCP starts
1527 probing the connection, interval how often to probe, and
1528 timeout the time before giving up.
1529
1530 If you run Squid on a dual-homed machine with an internal
1531 and an external interface we recommend you to specify the
1532 internal address:port in http_port. This way Squid will only be
1533 visible on the internal address.
1534
1535 NOCOMMENT_START
1536
1537 # Squid normally listens to port 3128
1538 http_port @DEFAULT_HTTP_PORT@
1539 NOCOMMENT_END
1540 DOC_END
1541
1542 NAME: https_port
1543 IFDEF: USE_SSL
1544 TYPE: https_port_list
1545 DEFAULT: none
1546 LOC: Config.Sockaddr.https
1547 DOC_START
1548 Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1549
1550 The socket address where Squid will listen for client requests made
1551 over TLS or SSL connections. Commonly referred to as HTTPS.
1552
1553 This is most useful for situations where you are running squid in
1554 accelerator mode and you want to do the SSL work at the accelerator level.
1555
1556 You may specify multiple socket addresses on multiple lines,
1557 each with their own SSL certificate and/or options.
1558
1559 Modes:
1560
1561 accel Accelerator / reverse proxy mode
1562
1563 tproxy Support Linux TPROXY for spoofing outgoing
1564 connections using the client IP address.
1565 NP: disables authentication and maybe IPv6 on the port.
1566
1567 ssl-bump Intercept each SSL request matching ssl_bump ACL,
1568 establish secure connection with the client and with
1569 the server, decrypt HTTP messages as they pass through
1570 Squid, and treat them as unencrypted HTTP messages,
1571 becoming the man-in-the-middle.
1572
1573 The ssl_bump option is required to fully enable
1574 the SslBump feature.
1575
1576 Requires tproxy.
1577
1578 Omitting the mode flag causes default forward proxy mode to be used.
1579
1580
1581 See http_port for a list of generic options
1582
1583
1584 SSL Options:
1585
1586 cert= Path to SSL certificate (PEM format).
1587
1588 key= Path to SSL private key file (PEM format)
1589 if not specified, the certificate file is
1590 assumed to be a combined certificate and
1591 key file.
1592
1593 version= The version of SSL/TLS supported
1594 1 automatic (default)
1595 2 SSLv2 only
1596 3 SSLv3 only
1597 4 TLSv1 only
1598
1599 cipher= Colon separated list of supported ciphers.
1600
1601 options= Various SSL engine options. The most important
1602 being:
1603 NO_SSLv2 Disallow the use of SSLv2
1604 NO_SSLv3 Disallow the use of SSLv3
1605 NO_TLSv1 Disallow the use of TLSv1
1606 SINGLE_DH_USE Always create a new key when using
1607 temporary/ephemeral DH key exchanges
1608 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1609 documentation for a complete list of options.
1610
1611 clientca= File containing the list of CAs to use when
1612 requesting a client certificate.
1613
1614 cafile= File containing additional CA certificates to
1615 use when verifying client certificates. If unset
1616 clientca will be used.
1617
1618 capath= Directory containing additional CA certificates
1619 and CRL lists to use when verifying client certificates.
1620
1621 crlfile= File of additional CRL lists to use when verifying
1622 the client certificate, in addition to CRLs stored in
1623 the capath. Implies VERIFY_CRL flag below.
1624
1625 dhparams= File containing DH parameters for temporary/ephemeral
1626 DH key exchanges.
1627
1628 sslflags= Various flags modifying the use of SSL:
1629 DELAYED_AUTH
1630 Don't request client certificates
1631 immediately, but wait until acl processing
1632 requires a certificate (not yet implemented).
1633 NO_DEFAULT_CA
1634 Don't use the default CA lists built in
1635 to OpenSSL.
1636 NO_SESSION_REUSE
1637 Don't allow for session reuse. Each connection
1638 will result in a new SSL session.
1639 VERIFY_CRL
1640 Verify CRL lists when accepting client
1641 certificates.
1642 VERIFY_CRL_ALL
1643 Verify CRL lists for all certificates in the
1644 client certificate chain.
1645
1646 sslcontext= SSL session ID context identifier.
1647
1648 generate-host-certificates[=<on|off>]
1649 Dynamically create SSL server certificates for the
1650 destination hosts of bumped SSL requests.When
1651 enabled, the cert and key options are used to sign
1652 generated certificates. Otherwise generated
1653 certificate will be selfsigned.
1654 If there is CA certificate life time of generated
1655 certificate equals lifetime of CA certificate. If
1656 generated certificate is selfsigned lifetime is three
1657 years.
1658 This option is enabled by default when SslBump is used.
1659 See the sslBump option above for more information.
1660
1661 dynamic_cert_mem_cache_size=SIZE
1662 Approximate total RAM size spent on cached generated
1663 certificates. If set to zero, caching is disabled. The
1664 default value is 4MB. An average XXX-bit certificate
1665 consumes about XXX bytes of RAM.
1666
1667 See http_port for a list of available options.
1668 DOC_END
1669
1670 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
1671 TYPE: acl_tos
1672 DEFAULT: none
1673 LOC: Ip::Qos::TheConfig.tosToServer
1674 DOC_START
1675 Allows you to select a TOS/Diffserv value for packets outgoing
1676 on the server side, based on an ACL.
1677
1678 tcp_outgoing_tos ds-field [!]aclname ...
1679
1680 Example where normal_service_net uses the TOS value 0x00
1681 and good_service_net uses 0x20
1682
1683 acl normal_service_net src 10.0.0.0/24
1684 acl good_service_net src 10.0.1.0/24
1685 tcp_outgoing_tos 0x00 normal_service_net
1686 tcp_outgoing_tos 0x20 good_service_net
1687
1688 TOS/DSCP values really only have local significance - so you should
1689 know what you're specifying. For more information, see RFC2474,
1690 RFC2475, and RFC3260.
1691
1692 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1693 "default" to use whatever default your host has. Note that in
1694 practice often only multiples of 4 is usable as the two rightmost bits
1695 have been redefined for use by ECN (RFC 3168 section 23.1).
1696
1697 Processing proceeds in the order specified, and stops at first fully
1698 matching line.
1699 DOC_END
1700
1701 NAME: clientside_tos
1702 TYPE: acl_tos
1703 DEFAULT: none
1704 LOC: Ip::Qos::TheConfig.tosToClient
1705 DOC_START
1706 Allows you to select a TOS/Diffserv value for packets being transmitted
1707 on the client-side, based on an ACL.
1708
1709 clientside_tos ds-field [!]aclname ...
1710
1711 Example where normal_service_net uses the TOS value 0x00
1712 and good_service_net uses 0x20
1713
1714 acl normal_service_net src 10.0.0.0/24
1715 acl good_service_net src 10.0.1.0/24
1716 clientside_tos 0x00 normal_service_net
1717 clientside_tos 0x20 good_service_net
1718
1719 Note: This feature is incompatible with qos_flows. Any TOS values set here
1720 will be overwritten by TOS values in qos_flows.
1721 DOC_END
1722
1723 NAME: tcp_outgoing_mark
1724 TYPE: acl_nfmark
1725 IFDEF: SO_MARK&&USE_LIBCAP
1726 DEFAULT: none
1727 LOC: Ip::Qos::TheConfig.nfmarkToServer
1728 DOC_START
1729 Allows you to apply a Netfilter mark value to outgoing packets
1730 on the server side, based on an ACL.
1731
1732 tcp_outgoing_mark mark-value [!]aclname ...
1733
1734 Example where normal_service_net uses the mark value 0x00
1735 and good_service_net uses 0x20
1736
1737 acl normal_service_net src 10.0.0.0/24
1738 acl good_service_net src 10.0.1.0/24
1739 tcp_outgoing_mark 0x00 normal_service_net
1740 tcp_outgoing_mark 0x20 good_service_net
1741 DOC_END
1742
1743 NAME: clientside_mark
1744 TYPE: acl_nfmark
1745 IFDEF: SO_MARK&&USE_LIBCAP
1746 DEFAULT: none
1747 LOC: Ip::Qos::TheConfig.nfmarkToClient
1748 DOC_START
1749 Allows you to apply a Netfilter mark value to packets being transmitted
1750 on the client-side, based on an ACL.
1751
1752 clientside_mark mark-value [!]aclname ...
1753
1754 Example where normal_service_net uses the mark value 0x00
1755 and good_service_net uses 0x20
1756
1757 acl normal_service_net src 10.0.0.0/24
1758 acl good_service_net src 10.0.1.0/24
1759 clientside_mark 0x00 normal_service_net
1760 clientside_mark 0x20 good_service_net
1761
1762 Note: This feature is incompatible with qos_flows. Any mark values set here
1763 will be overwritten by mark values in qos_flows.
1764 DOC_END
1765
1766 NAME: qos_flows
1767 TYPE: QosConfig
1768 IFDEF: USE_QOS_TOS
1769 DEFAULT: none
1770 LOC: Ip::Qos::TheConfig
1771 DOC_START
1772 Allows you to select a TOS/DSCP value to mark outgoing
1773 connections with, based on where the reply was sourced. For
1774 platforms using netfilter, allows you to set a netfilter mark
1775 value instead of, or in addition to, a TOS value.
1776
1777 TOS values really only have local significance - so you should
1778 know what you're specifying. For more information, see RFC2474,
1779 RFC2475, and RFC3260.
1780
1781 The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
1782 in practice often only multiples of 4 is usable as the two rightmost bits
1783 have been redefined for use by ECN (RFC 3168 section 23.1).
1784
1785 Mark values can be any unsigned 32-bit integer value.
1786
1787 This setting is configured by setting the following values:
1788
1789 tos|mark Whether to set TOS or netfilter mark values
1790
1791 local-hit=0xFF Value to mark local cache hits.
1792
1793 sibling-hit=0xFF Value to mark hits from sibling peers.
1794
1795 parent-hit=0xFF Value to mark hits from parent peers.
1796
1797 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
1798 over the preserve-miss feature (see below), unless
1799 mask is specified, in which case only the bits
1800 specified in the mask are written.
1801
1802 The TOS variant of the following features are only possible on Linux
1803 and require your kernel to be patched with the TOS preserving ZPH
1804 patch, available from http://zph.bratcheda.org
1805 No patch is needed to preserve the netfilter mark, which will work
1806 with all variants of netfilter.
1807
1808 disable-preserve-miss
1809 This option disables the preservation of the TOS or netfilter
1810 mark. By default, the existing TOS or netfilter mark value of
1811 the response coming from the remote server will be retained
1812 and masked with miss-mark.
1813 NOTE: in the case of a netfilter mark, the mark must be set on
1814 the connection (using the CONNMARK target) not on the packet
1815 (MARK target).
1816
1817 miss-mask=0xFF
1818 Allows you to mask certain bits in the TOS or mark value
1819 received from the remote server, before copying the value to
1820 the TOS sent towards clients.
1821 Default for tos: 0xFF (TOS from server is not changed).
1822 Default for mark: 0xFFFFFFFF (mark from server is not changed).
1823
1824 All of these features require the --enable-zph-qos compilation flag
1825 (enabled by default). Netfilter marking also requires the
1826 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
1827 libcap 2.09+ (--with-libcap).
1828
1829 DOC_END
1830
1831 NAME: tcp_outgoing_address
1832 TYPE: acl_address
1833 DEFAULT: none
1834 LOC: Config.accessList.outgoing_address
1835 DOC_START
1836 Allows you to map requests to different outgoing IP addresses
1837 based on the username or source address of the user making
1838 the request.
1839
1840 tcp_outgoing_address ipaddr [[!]aclname] ...
1841
1842 For example;
1843 Forwarding clients with dedicated IPs for certain subnets.
1844
1845 acl normal_service_net src 10.0.0.0/24
1846 acl good_service_net src 10.0.2.0/24
1847
1848 tcp_outgoing_address 2001:db8::c001 good_service_net
1849 tcp_outgoing_address 10.1.0.2 good_service_net
1850
1851 tcp_outgoing_address 2001:db8::beef normal_service_net
1852 tcp_outgoing_address 10.1.0.1 normal_service_net
1853
1854 tcp_outgoing_address 2001:db8::1
1855 tcp_outgoing_address 10.1.0.3
1856
1857 Processing proceeds in the order specified, and stops at first fully
1858 matching line.
1859
1860 Squid will add an implicit IP version test to each line.
1861 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
1862 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
1863
1864
1865 NOTE: The use of this directive using client dependent ACLs is
1866 incompatible with the use of server side persistent connections. To
1867 ensure correct results it is best to set server_persistent_connections
1868 to off when using this directive in such configurations.
1869
1870 NOTE: The use of this directive to set a local IP on outgoing TCP links
1871 is incompatible with using TPROXY to set client IP out outbound TCP links.
1872 When needing to contact peers use the no-tproxy cache_peer option and the
1873 client_dst_passthru directive re-enable normal forwarding such as this.
1874
1875 DOC_END
1876
1877 NAME: host_verify_strict
1878 TYPE: onoff
1879 DEFAULT: off
1880 LOC: Config.onoff.hostStrictVerify
1881 DOC_START
1882 Regardless of this option setting, when dealing with intercepted
1883 traffic, Squid always verifies that the destination IP address matches
1884 the Host header domain or IP (called 'authority form URL').
1885
1886 This enforcement is performed to satisfy a MUST-level requirement in
1887 RFC 2616 section 14.23: "The Host field value MUST represent the naming
1888 authority of the origin server or gateway given by the original URL".
1889
1890 When set to ON:
1891 Squid always responds with an HTTP 409 (Conflict) error
1892 page and logs a security warning if there is no match.
1893
1894 Squid verifies that the destination IP address matches
1895 the Host header for forward-proxy and reverse-proxy traffic
1896 as well. For those traffic types, Squid also enables the
1897 following checks, comparing the corresponding Host header
1898 and Request-URI components:
1899
1900 * The host names (domain or IP) must be identical,
1901 but valueless or missing Host header disables all checks.
1902 For the two host names to match, both must be either IP
1903 or FQDN.
1904
1905 * Port numbers must be identical, but if a port is missing
1906 the scheme-default port is assumed.
1907
1908
1909 When set to OFF (the default):
1910 Squid allows suspicious requests to continue but logs a
1911 security warning and blocks caching of the response.
1912
1913 * Forward-proxy traffic is not checked at all.
1914
1915 * Reverse-proxy traffic is not checked at all.
1916
1917 * Intercepted traffic which passes verification is handled
1918 normally.
1919
1920 For now it also forces suspicious requests to go DIRECT to the
1921 original destination, overriding client_dst_passthru for
1922 intercepted requests which fail Host: verification.
1923
1924 For now suspicious intercepted CONNECT requests are always
1925 responded to with an HTTP 409 (Conflict) error page.
1926 DOC_END
1927
1928 NAME: client_dst_passthru
1929 TYPE: onoff
1930 DEFAULT: on
1931 LOC: Config.onoff.client_dst_passthru
1932 DOC_START
1933 With NAT or TPROXY intercepted traffic Squid may pass the request
1934 directly to the original client destination IP or seek a faster
1935 source.
1936
1937 This option (on by default) prevents cache_peer and alternative DNS
1938 entries being used on intercepted traffic. Both of which lead to
1939 the security vulnerability outlined below.
1940
1941 SECURITY WARNING:
1942
1943 This directive should only be disabled if cache_peer are required.
1944
1945 As described in CVE-2009-0801 when the Host: header alone is used
1946 to determine the destination of a request it becomes trivial for
1947 malicious scripts on remote websites to bypass browser same-origin
1948 security policy and sandboxing protections.
1949
1950 The cause of this is that such applets are allowed to perform their
1951 own HTTP stack, in which case the same-origin policy of the browser
1952 sandbox only verifies that the applet tries to contact the same IP
1953 as from where it was loaded at the IP level. The Host: header may
1954 be different from the connected IP and approved origin.
1955
1956 DOC_END
1957
1958 COMMENT_START
1959 SSL OPTIONS
1960 -----------------------------------------------------------------------------
1961 COMMENT_END
1962
1963 NAME: ssl_unclean_shutdown
1964 IFDEF: USE_SSL
1965 TYPE: onoff
1966 DEFAULT: off
1967 LOC: Config.SSL.unclean_shutdown
1968 DOC_START
1969 Some browsers (especially MSIE) bugs out on SSL shutdown
1970 messages.
1971 DOC_END
1972
1973 NAME: ssl_engine
1974 IFDEF: USE_SSL
1975 TYPE: string
1976 LOC: Config.SSL.ssl_engine
1977 DEFAULT: none
1978 DOC_START
1979 The OpenSSL engine to use. You will need to set this if you
1980 would like to use hardware SSL acceleration for example.
1981 DOC_END
1982
1983 NAME: sslproxy_client_certificate
1984 IFDEF: USE_SSL
1985 DEFAULT: none
1986 LOC: Config.ssl_client.cert
1987 TYPE: string
1988 DOC_START
1989 Client SSL Certificate to use when proxying https:// URLs
1990 DOC_END
1991
1992 NAME: sslproxy_client_key
1993 IFDEF: USE_SSL
1994 DEFAULT: none
1995 LOC: Config.ssl_client.key
1996 TYPE: string
1997 DOC_START
1998 Client SSL Key to use when proxying https:// URLs
1999 DOC_END
2000
2001 NAME: sslproxy_version
2002 IFDEF: USE_SSL
2003 DEFAULT: 1
2004 LOC: Config.ssl_client.version
2005 TYPE: int
2006 DOC_START
2007 SSL version level to use when proxying https:// URLs
2008 DOC_END
2009
2010 NAME: sslproxy_options
2011 IFDEF: USE_SSL
2012 DEFAULT: none
2013 LOC: Config.ssl_client.options
2014 TYPE: string
2015 DOC_START
2016 SSL implementation options to use when proxying https:// URLs
2017
2018 The most important being:
2019
2020 NO_SSLv2 Disallow the use of SSLv2
2021 NO_SSLv3 Disallow the use of SSLv3
2022 NO_TLSv1 Disallow the use of TLSv1
2023 SINGLE_DH_USE
2024 Always create a new key when using temporary/ephemeral
2025 DH key exchanges
2026 SSL_OP_NO_TICKET
2027 Disable use of RFC5077 session tickets. Some servers
2028 may have problems understanding the TLS extension due
2029 to ambiguous specification in RFC4507.
2030 ALL Enable various bug workarounds suggested as "harmless"
2031 by OpenSSL. Be warned that this may reduce SSL/TLS
2032 strength to some attacks.
2033
2034 See the OpenSSL SSL_CTX_set_options documentation for a
2035 complete list of possible options.
2036 DOC_END
2037
2038 NAME: sslproxy_cipher
2039 IFDEF: USE_SSL
2040 DEFAULT: none
2041 LOC: Config.ssl_client.cipher
2042 TYPE: string
2043 DOC_START
2044 SSL cipher list to use when proxying https:// URLs
2045
2046 Colon separated list of supported ciphers.
2047 DOC_END
2048
2049 NAME: sslproxy_cafile
2050 IFDEF: USE_SSL
2051 DEFAULT: none
2052 LOC: Config.ssl_client.cafile
2053 TYPE: string
2054 DOC_START
2055 file containing CA certificates to use when verifying server
2056 certificates while proxying https:// URLs
2057 DOC_END
2058
2059 NAME: sslproxy_capath
2060 IFDEF: USE_SSL
2061 DEFAULT: none
2062 LOC: Config.ssl_client.capath
2063 TYPE: string
2064 DOC_START
2065 directory containing CA certificates to use when verifying
2066 server certificates while proxying https:// URLs
2067 DOC_END
2068
2069 NAME: ssl_bump
2070 IFDEF: USE_SSL
2071 TYPE: acl_access
2072 LOC: Config.accessList.ssl_bump
2073 DEFAULT: none
2074 DOC_START
2075 This ACL controls which CONNECT requests to an http_port
2076 marked with an sslBump flag are actually "bumped". Please
2077 see the sslBump flag of an http_port option for more details
2078 about decoding proxied SSL connections.
2079
2080 By default, no requests are bumped.
2081
2082 See also: http_port ssl-bump
2083
2084 This clause supports both fast and slow acl types.
2085 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2086
2087
2088 # Example: Bump all requests except those originating from localhost and
2089 # those going to webax.com or example.com sites.
2090
2091 acl localhost src 127.0.0.1/32
2092 acl broken_sites dstdomain .webax.com
2093 acl broken_sites dstdomain .example.com
2094 ssl_bump deny localhost
2095 ssl_bump deny broken_sites
2096 ssl_bump allow all
2097 DOC_END
2098
2099 NAME: sslproxy_flags
2100 IFDEF: USE_SSL
2101 DEFAULT: none
2102 LOC: Config.ssl_client.flags
2103 TYPE: string
2104 DOC_START
2105 Various flags modifying the use of SSL while proxying https:// URLs:
2106 DONT_VERIFY_PEER Accept certificates that fail verification.
2107 For refined control, see sslproxy_cert_error.
2108 NO_DEFAULT_CA Don't use the default CA list built in
2109 to OpenSSL.
2110 DOC_END
2111
2112 NAME: sslproxy_cert_error
2113 IFDEF: USE_SSL
2114 DEFAULT: none
2115 LOC: Config.ssl_client.cert_error
2116 TYPE: acl_access
2117 DOC_START
2118 Use this ACL to bypass server certificate validation errors.
2119
2120 For example, the following lines will bypass all validation errors
2121 when talking to servers located at 172.16.0.0/16. All other
2122 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2123
2124 acl BrokenServersAtTrustedIP dst 172.16.0.0/16
2125 sslproxy_cert_error allow BrokenServersAtTrustedIP
2126 sslproxy_cert_error deny all
2127
2128 This clause only supports fast acl types.
2129 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2130 Using slow acl types may result in server crashes
2131
2132 Without this option, all server certificate validation errors
2133 terminate the transaction. Bypassing validation errors is dangerous
2134 because an error usually implies that the server cannot be trusted and
2135 the connection may be insecure.
2136
2137 See also: sslproxy_flags and DONT_VERIFY_PEER.
2138
2139 Default setting: sslproxy_cert_error deny all
2140 DOC_END
2141
2142 NAME: sslproxy_cert_sign
2143 IFDEF: USE_SSL
2144 DEFAULT: none
2145 POSTSCRIPTUM: signUntrusted ssl::certUntrusted
2146 POSTSCRIPTUM: signSelf ssl::certSelfSigned
2147 POSTSCRIPTUM: signTrusted all
2148 TYPE: sslproxy_cert_sign
2149 LOC: Config.ssl_client.cert_sign
2150 DOC_START
2151
2152 sslproxy_cert_sign <signing algorithm> acl ...
2153
2154 The following certificate signing algorithms are supported:
2155 signTrusted
2156 Sign using the configured CA certificate which is usually
2157 placed in and trusted by end-user browsers. This is the
2158 default for trusted origin server certificates.
2159 signUntrusted
2160 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2161 This is the default for untrusted origin server certificates
2162 that are not self-signed (see ssl::certUntrusted).
2163 signSelf
2164 Sign using a self-signed certificate with the right CN to
2165 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2166 browser. This is the default for self-signed origin server
2167 certificates (see ssl::certSelfSigned).
2168
2169 This clause only supports fast acl types.
2170
2171 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2172 signing algorithm to generate the certificate and ignores all
2173 subsequent sslproxy_cert_sign options (the first match wins). If no
2174 acl(s) match, the default signing algorithm is determined by errors
2175 detected when obtaining and validating the origin server certificate.
2176
2177 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2178 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2179 CONNECT request that carries a domain name. In all other cases (CONNECT
2180 to an IP address or an intercepted SSL connection), Squid cannot detect
2181 the domain mismatch at certificate generation time when
2182 bump-server-first is used.
2183 DOC_END
2184
2185 NAME: sslproxy_cert_adapt
2186 IFDEF: USE_SSL
2187 DEFAULT: none
2188 TYPE: sslproxy_cert_adapt
2189 LOC: Config.ssl_client.cert_adapt
2190 DOC_START
2191
2192 sslproxy_cert_adapt <adaptation algorithm> acl ...
2193
2194 The following certificate adaptation algorithms are supported:
2195 setValidAfter
2196 Sets the "Not After" property to the "Not After" property of
2197 the CA certificate used to sign generated certificates.
2198 setValidBefore
2199 Sets the "Not Before" property to the "Not Before" property of
2200 the CA certificate used to sign generated certificates.
2201 setCommonName or setCommonName{CN}
2202 Sets Subject.CN property to the host name specified as a
2203 CN parameter or, if no explicit CN parameter was specified,
2204 extracted from the CONNECT request. It is a misconfiguration
2205 to use setCommonName without an explicit parameter for
2206 intercepted or tproxied SSL connections.
2207
2208 This clause only supports fast acl types.
2209
2210 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2211 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2212 corresponding adaptation algorithm to generate the certificate and
2213 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2214 group (i.e., the first match wins within each algorithm group). If no
2215 acl(s) match, the default mimicking action takes place.
2216
2217 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2218 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2219 CONNECT request that carries a domain name. In all other cases (CONNECT
2220 to an IP address or an intercepted SSL connection), Squid cannot detect
2221 the domain mismatch at certificate generation time when
2222 bump-server-first is used.
2223 DOC_END
2224
2225 NAME: sslpassword_program
2226 IFDEF: USE_SSL
2227 DEFAULT: none
2228 LOC: Config.Program.ssl_password
2229 TYPE: string
2230 DOC_START
2231 Specify a program used for entering SSL key passphrases
2232 when using encrypted SSL certificate keys. If not specified
2233 keys must either be unencrypted, or Squid started with the -N
2234 option to allow it to query interactively for the passphrase.
2235
2236 The key file name is given as argument to the program allowing
2237 selection of the right password if you have multiple encrypted
2238 keys.
2239 DOC_END
2240
2241 COMMENT_START
2242 OPTIONS RELATING TO EXTERNAL SSL_CRTD
2243 -----------------------------------------------------------------------------
2244 COMMENT_END
2245
2246 NAME: sslcrtd_program
2247 TYPE: eol
2248 IFDEF: USE_SSL_CRTD
2249 DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
2250 LOC: Ssl::TheConfig.ssl_crtd
2251 DOC_START
2252 Specify the location and options of the executable for ssl_crtd process.
2253 @DEFAULT_SSL_CRTD@ program requires -s and -M parameters
2254 For more information use:
2255 @DEFAULT_SSL_CRTD@ -h
2256 DOC_END
2257
2258 NAME: sslcrtd_children
2259 TYPE: HelperChildConfig
2260 IFDEF: USE_SSL_CRTD
2261 DEFAULT: 32 startup=5 idle=1
2262 LOC: Ssl::TheConfig.ssl_crtdChildren
2263 DOC_START
2264 The maximum number of processes spawn to service ssl server.
2265 The maximum this may be safely set to is 32.
2266
2267 The startup= and idle= options allow some measure of skew in your
2268 tuning.
2269
2270 startup=N
2271
2272 Sets the minimum number of processes to spawn when Squid
2273 starts or reconfigures. When set to zero the first request will
2274 cause spawning of the first child process to handle it.
2275
2276 Starting too few children temporary slows Squid under load while it
2277 tries to spawn enough additional processes to cope with traffic.
2278
2279 idle=N
2280
2281 Sets a minimum of how many processes Squid is to try and keep available
2282 at all times. When traffic begins to rise above what the existing
2283 processes can handle this many more will be spawned up to the maximum
2284 configured. A minimum setting of 1 is required.
2285
2286 You must have at least one ssl_crtd process.
2287 DOC_END
2288
2289 COMMENT_START
2290 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2291 -----------------------------------------------------------------------------
2292 COMMENT_END
2293
2294 NAME: cache_peer
2295 TYPE: peer
2296 DEFAULT: none
2297 LOC: Config.peers
2298 DOC_START
2299 To specify other caches in a hierarchy, use the format:
2300
2301 cache_peer hostname type http-port icp-port [options]
2302
2303 For example,
2304
2305 # proxy icp
2306 # hostname type port port options
2307 # -------------------- -------- ----- ----- -----------
2308 cache_peer parent.foo.net parent 3128 3130 default
2309 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2310 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2311 cache_peer example.com parent 80 0 default
2312 cache_peer cdn.example.com sibling 3128 0
2313
2314 type: either 'parent', 'sibling', or 'multicast'.
2315
2316 proxy-port: The port number where the peer accept HTTP requests.
2317 For other Squid proxies this is usually 3128
2318 For web servers this is usually 80
2319
2320 icp-port: Used for querying neighbor caches about objects.
2321 Set to 0 if the peer does not support ICP or HTCP.
2322 See ICP and HTCP options below for additional details.
2323
2324
2325 ==== ICP OPTIONS ====
2326
2327 You MUST also set icp_port and icp_access explicitly when using these options.
2328 The defaults will prevent peer traffic using ICP.
2329
2330
2331 no-query Disable ICP queries to this neighbor.
2332
2333 multicast-responder
2334 Indicates the named peer is a member of a multicast group.
2335 ICP queries will not be sent directly to the peer, but ICP
2336 replies will be accepted from it.
2337
2338 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2339 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2340
2341 background-ping
2342 To only send ICP queries to this neighbor infrequently.
2343 This is used to keep the neighbor round trip time updated
2344 and is usually used in conjunction with weighted-round-robin.
2345
2346
2347 ==== HTCP OPTIONS ====
2348
2349 You MUST also set htcp_port and htcp_access explicitly when using these options.
2350 The defaults will prevent peer traffic using HTCP.
2351
2352
2353 htcp Send HTCP, instead of ICP, queries to the neighbor.
2354 You probably also want to set the "icp-port" to 4827
2355 instead of 3130. This directive accepts a comma separated
2356 list of options described below.
2357
2358 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2359
2360 htcp=no-clr Send HTCP to the neighbor but without
2361 sending any CLR requests. This cannot be used with
2362 only-clr.
2363
2364 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2365 This cannot be used with no-clr.
2366
2367 htcp=no-purge-clr
2368 Send HTCP to the neighbor including CLRs but only when
2369 they do not result from PURGE requests.
2370
2371 htcp=forward-clr
2372 Forward any HTCP CLR requests this proxy receives to the peer.
2373
2374
2375 ==== PEER SELECTION METHODS ====
2376
2377 The default peer selection method is ICP, with the first responding peer
2378 being used as source. These options can be used for better load balancing.
2379
2380
2381 default This is a parent cache which can be used as a "last-resort"
2382 if a peer cannot be located by any of the peer-selection methods.
2383 If specified more than once, only the first is used.
2384
2385 round-robin Load-Balance parents which should be used in a round-robin
2386 fashion in the absence of any ICP queries.
2387 weight=N can be used to add bias.
2388
2389 weighted-round-robin
2390 Load-Balance parents which should be used in a round-robin
2391 fashion with the frequency of each parent being based on the
2392 round trip time. Closer parents are used more often.
2393 Usually used for background-ping parents.
2394 weight=N can be used to add bias.
2395
2396 carp Load-Balance parents which should be used as a CARP array.
2397 The requests will be distributed among the parents based on the
2398 CARP load balancing hash function based on their weight.
2399
2400 userhash Load-balance parents based on the client proxy_auth or ident username.
2401
2402 sourcehash Load-balance parents based on the client source IP.
2403
2404 multicast-siblings
2405 To be used only for cache peers of type "multicast".
2406 ALL members of this multicast group have "sibling"
2407 relationship with it, not "parent". This is to a multicast
2408 group when the requested object would be fetched only from
2409 a "parent" cache, anyway. It's useful, e.g., when
2410 configuring a pool of redundant Squid proxies, being
2411 members of the same multicast group.
2412
2413
2414 ==== PEER SELECTION OPTIONS ====
2415
2416 weight=N use to affect the selection of a peer during any weighted
2417 peer-selection mechanisms.
2418 The weight must be an integer; default is 1,
2419 larger weights are favored more.
2420 This option does not affect parent selection if a peering
2421 protocol is not in use.
2422
2423 basetime=N Specify a base amount to be subtracted from round trip
2424 times of parents.
2425 It is subtracted before division by weight in calculating
2426 which parent to fectch from. If the rtt is less than the
2427 base time the rtt is set to a minimal value.
2428
2429 ttl=N Specify a TTL to use when sending multicast ICP queries
2430 to this address.
2431 Only useful when sending to a multicast group.
2432 Because we don't accept ICP replies from random
2433 hosts, you must configure other group members as
2434 peers with the 'multicast-responder' option.
2435
2436 no-delay To prevent access to this neighbor from influencing the
2437 delay pools.
2438
2439 digest-url=URL Tell Squid to fetch the cache digest (if digests are
2440 enabled) for this host from the specified URL rather
2441 than the Squid default location.
2442
2443
2444 ==== CARP OPTIONS ====
2445
2446 carp-key=key-specification
2447 use a different key than the full URL to hash against the peer.
2448 the key-specification is a comma-separated list of the keywords
2449 scheme, host, port, path, params
2450 Order is not important.
2451
2452 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2453
2454 originserver Causes this parent to be contacted as an origin server.
2455 Meant to be used in accelerator setups when the peer
2456 is a web server.
2457
2458 forceddomain=name
2459 Set the Host header of requests forwarded to this peer.
2460 Useful in accelerator setups where the server (peer)
2461 expects a certain domain name but clients may request
2462 others. ie example.com or www.example.com
2463
2464 no-digest Disable request of cache digests.
2465
2466 no-netdb-exchange
2467 Disables requesting ICMP RTT database (NetDB).
2468
2469
2470 ==== AUTHENTICATION OPTIONS ====
2471
2472 login=user:password
2473 If this is a personal/workgroup proxy and your parent
2474 requires proxy authentication.
2475
2476 Note: The string can include URL escapes (i.e. %20 for
2477 spaces). This also means % must be written as %%.
2478
2479 login=PASSTHRU
2480 Send login details received from client to this peer.
2481 Both Proxy- and WWW-Authorization headers are passed
2482 without alteration to the peer.
2483 Authentication is not required by Squid for this to work.
2484
2485 Note: This will pass any form of authentication but
2486 only Basic auth will work through a proxy unless the
2487 connection-auth options are also used.
2488
2489 login=PASS Send login details received from client to this peer.
2490 Authentication is not required by this option.
2491
2492 If there are no client-provided authentication headers
2493 to pass on, but username and password are available
2494 from an external ACL user= and password= result tags
2495 they may be sent instead.
2496
2497 Note: To combine this with proxy_auth both proxies must
2498 share the same user database as HTTP only allows for
2499 a single login (one for proxy, one for origin server).
2500 Also be warned this will expose your users proxy
2501 password to the peer. USE WITH CAUTION
2502
2503 login=*:password
2504 Send the username to the upstream cache, but with a
2505 fixed password. This is meant to be used when the peer
2506 is in another administrative domain, but it is still
2507 needed to identify each user.
2508 The star can optionally be followed by some extra
2509 information which is added to the username. This can
2510 be used to identify this proxy to the peer, similar to
2511 the login=username:password option above.
2512
2513 login=NEGOTIATE
2514 If this is a personal/workgroup proxy and your parent
2515 requires a secure proxy authentication.
2516 The first principal from the default keytab or defined by
2517 the environment variable KRB5_KTNAME will be used.
2518
2519 WARNING: The connection may transmit requests from multiple
2520 clients. Negotiate often assumes end-to-end authentication
2521 and a single-client. Which is not strictly true here.
2522
2523 login=NEGOTIATE:principal_name
2524 If this is a personal/workgroup proxy and your parent
2525 requires a secure proxy authentication.
2526 The principal principal_name from the default keytab or
2527 defined by the environment variable KRB5_KTNAME will be
2528 used.
2529
2530 WARNING: The connection may transmit requests from multiple
2531 clients. Negotiate often assumes end-to-end authentication
2532 and a single-client. Which is not strictly true here.
2533
2534 connection-auth=on|off
2535 Tell Squid that this peer does or not support Microsoft
2536 connection oriented authentication, and any such
2537 challenges received from there should be ignored.
2538 Default is auto to automatically determine the status
2539 of the peer.
2540
2541
2542 ==== SSL / HTTPS / TLS OPTIONS ====
2543
2544 ssl Encrypt connections to this peer with SSL/TLS.
2545
2546 sslcert=/path/to/ssl/certificate
2547 A client SSL certificate to use when connecting to
2548 this peer.
2549
2550 sslkey=/path/to/ssl/key
2551 The private SSL key corresponding to sslcert above.
2552 If 'sslkey' is not specified 'sslcert' is assumed to
2553 reference a combined file containing both the
2554 certificate and the key.
2555
2556 sslversion=1|2|3|4
2557 The SSL version to use when connecting to this peer
2558 1 = automatic (default)
2559 2 = SSL v2 only
2560 3 = SSL v3 only
2561 4 = TLS v1 only
2562
2563 sslcipher=... The list of valid SSL ciphers to use when connecting
2564 to this peer.
2565
2566 ssloptions=... Specify various SSL implementation options:
2567
2568 NO_SSLv2 Disallow the use of SSLv2
2569 NO_SSLv3 Disallow the use of SSLv3
2570 NO_TLSv1 Disallow the use of TLSv1
2571 SINGLE_DH_USE
2572 Always create a new key when using
2573 temporary/ephemeral DH key exchanges
2574 ALL Enable various bug workarounds
2575 suggested as "harmless" by OpenSSL
2576 Be warned that this reduces SSL/TLS
2577 strength to some attacks.
2578
2579 See the OpenSSL SSL_CTX_set_options documentation for a
2580 more complete list.
2581
2582 sslcafile=... A file containing additional CA certificates to use
2583 when verifying the peer certificate.
2584
2585 sslcapath=... A directory containing additional CA certificates to
2586 use when verifying the peer certificate.
2587
2588 sslcrlfile=... A certificate revocation list file to use when
2589 verifying the peer certificate.
2590
2591 sslflags=... Specify various flags modifying the SSL implementation:
2592
2593 DONT_VERIFY_PEER
2594 Accept certificates even if they fail to
2595 verify.
2596 NO_DEFAULT_CA
2597 Don't use the default CA list built in
2598 to OpenSSL.
2599 DONT_VERIFY_DOMAIN
2600 Don't verify the peer certificate
2601 matches the server name
2602
2603 ssldomain= The peer name as advertised in it's certificate.
2604 Used for verifying the correctness of the received peer
2605 certificate. If not specified the peer hostname will be
2606 used.
2607
2608 front-end-https
2609 Enable the "Front-End-Https: On" header needed when
2610 using Squid as a SSL frontend in front of Microsoft OWA.
2611 See MS KB document Q307347 for details on this header.
2612 If set to auto the header will only be added if the
2613 request is forwarded as a https:// URL.
2614
2615
2616 ==== GENERAL OPTIONS ====
2617
2618 connect-timeout=N
2619 A peer-specific connect timeout.
2620 Also see the peer_connect_timeout directive.
2621
2622 connect-fail-limit=N
2623 How many times connecting to a peer must fail before
2624 it is marked as down. Default is 10.
2625
2626 allow-miss Disable Squid's use of only-if-cached when forwarding
2627 requests to siblings. This is primarily useful when
2628 icp_hit_stale is used by the sibling. To extensive use
2629 of this option may result in forwarding loops, and you
2630 should avoid having two-way peerings with this option.
2631 For example to deny peer usage on requests from peer
2632 by denying cache_peer_access if the source is a peer.
2633
2634 max-conn=N Limit the amount of connections Squid may open to this
2635 peer. see also
2636
2637 name=xxx Unique name for the peer.
2638 Required if you have multiple peers on the same host
2639 but different ports.
2640 This name can be used in cache_peer_access and similar
2641 directives to dentify the peer.
2642 Can be used by outgoing access controls through the
2643 peername ACL type.
2644
2645 no-tproxy Do not use the client-spoof TPROXY support when forwarding
2646 requests to this peer. Use normal address selection instead.
2647
2648 proxy-only objects fetched from the peer will not be stored locally.
2649
2650 DOC_END
2651
2652 NAME: cache_peer_domain cache_host_domain
2653 TYPE: hostdomain
2654 DEFAULT: none
2655 LOC: none
2656 DOC_START
2657 Use to limit the domains for which a neighbor cache will be
2658 queried. Usage:
2659
2660 cache_peer_domain cache-host domain [domain ...]
2661 cache_peer_domain cache-host !domain
2662
2663 For example, specifying
2664
2665 cache_peer_domain parent.foo.net .edu
2666
2667 has the effect such that UDP query packets are sent to
2668 'bigserver' only when the requested object exists on a
2669 server in the .edu domain. Prefixing the domainname
2670 with '!' means the cache will be queried for objects
2671 NOT in that domain.
2672
2673 NOTE: * Any number of domains may be given for a cache-host,
2674 either on the same or separate lines.
2675 * When multiple domains are given for a particular
2676 cache-host, the first matched domain is applied.
2677 * Cache hosts with no domain restrictions are queried
2678 for all requests.
2679 * There are no defaults.
2680 * There is also a 'cache_peer_access' tag in the ACL
2681 section.
2682 DOC_END
2683
2684 NAME: cache_peer_access
2685 TYPE: peer_access
2686 DEFAULT: none
2687 LOC: none
2688 DOC_START
2689 Similar to 'cache_peer_domain' but provides more flexibility by
2690 using ACL elements.
2691
2692 cache_peer_access cache-host allow|deny [!]aclname ...
2693
2694 The syntax is identical to 'http_access' and the other lists of
2695 ACL elements. See the comments for 'http_access' below, or
2696 the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
2697 DOC_END
2698
2699 NAME: neighbor_type_domain
2700 TYPE: hostdomaintype
2701 DEFAULT: none
2702 LOC: none
2703 DOC_START
2704 usage: neighbor_type_domain neighbor parent|sibling domain domain ...
2705
2706 Modifying the neighbor type for specific domains is now
2707 possible. You can treat some domains differently than the
2708 default neighbor type specified on the 'cache_peer' line.
2709 Normally it should only be necessary to list domains which
2710 should be treated differently because the default neighbor type
2711 applies for hostnames which do not match domains listed here.
2712
2713 EXAMPLE:
2714 cache_peer cache.foo.org parent 3128 3130
2715 neighbor_type_domain cache.foo.org sibling .com .net
2716 neighbor_type_domain cache.foo.org sibling .au .de
2717 DOC_END
2718
2719 NAME: dead_peer_timeout
2720 COMMENT: (seconds)
2721 DEFAULT: 10 seconds
2722 TYPE: time_t
2723 LOC: Config.Timeout.deadPeer
2724 DOC_START
2725 This controls how long Squid waits to declare a peer cache
2726 as "dead." If there are no ICP replies received in this
2727 amount of time, Squid will declare the peer dead and not
2728 expect to receive any further ICP replies. However, it
2729 continues to send ICP queries, and will mark the peer as
2730 alive upon receipt of the first subsequent ICP reply.
2731
2732 This timeout also affects when Squid expects to receive ICP
2733 replies from peers. If more than 'dead_peer' seconds have
2734 passed since the last ICP reply was received, Squid will not
2735 expect to receive an ICP reply on the next query. Thus, if
2736 your time between requests is greater than this timeout, you
2737 will see a lot of requests sent DIRECT to origin servers
2738 instead of to your parents.
2739 DOC_END
2740
2741 NAME: forward_max_tries
2742 DEFAULT: 10
2743 TYPE: int
2744 LOC: Config.forward_max_tries
2745 DOC_START
2746 Controls how many different forward paths Squid will try
2747 before giving up. See also forward_timeout.
2748
2749 NOTE: connect_retries (default: none) can make each of these
2750 possible forwarding paths be tried multiple times.
2751 DOC_END
2752
2753 NAME: hierarchy_stoplist
2754 TYPE: wordlist
2755 DEFAULT: none
2756 LOC: Config.hierarchy_stoplist
2757 DOC_START
2758 A list of words which, if found in a URL, cause the object to
2759 be handled directly by this cache. In other words, use this
2760 to not query neighbor caches for certain objects. You may
2761 list this option multiple times.
2762
2763 Example:
2764 hierarchy_stoplist cgi-bin ?
2765
2766 Note: never_direct overrides this option.
2767 DOC_END
2768
2769 COMMENT_START
2770 MEMORY CACHE OPTIONS
2771 -----------------------------------------------------------------------------
2772 COMMENT_END
2773
2774 NAME: cache_mem
2775 COMMENT: (bytes)
2776 TYPE: b_size_t
2777 DEFAULT: 256 MB
2778 LOC: Config.memMaxSize
2779 DOC_START
2780 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
2781 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
2782 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
2783 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
2784
2785 'cache_mem' specifies the ideal amount of memory to be used
2786 for:
2787 * In-Transit objects
2788 * Hot Objects
2789 * Negative-Cached objects
2790
2791 Data for these objects are stored in 4 KB blocks. This
2792 parameter specifies the ideal upper limit on the total size of
2793 4 KB blocks allocated. In-Transit objects take the highest
2794 priority.
2795
2796 In-transit objects have priority over the others. When
2797 additional space is needed for incoming data, negative-cached
2798 and hot objects will be released. In other words, the
2799 negative-cached and hot objects will fill up any unused space
2800 not needed for in-transit objects.
2801
2802 If circumstances require, this limit will be exceeded.
2803 Specifically, if your incoming request rate requires more than
2804 'cache_mem' of memory to hold in-transit objects, Squid will
2805 exceed this limit to satisfy the new requests. When the load
2806 decreases, blocks will be freed until the high-water mark is
2807 reached. Thereafter, blocks will be used to store hot
2808 objects.
2809
2810 If shared memory caching is enabled, Squid does not use the shared
2811 cache space for in-transit objects, but they still consume as much
2812 local memory as they need. For more details about the shared memory
2813 cache, see memory_cache_shared.
2814 DOC_END
2815
2816 NAME: maximum_object_size_in_memory
2817 COMMENT: (bytes)
2818 TYPE: b_size_t
2819 DEFAULT: 512 KB
2820 LOC: Config.Store.maxInMemObjSize
2821 DOC_START
2822 Objects greater than this size will not be attempted to kept in
2823 the memory cache. This should be set high enough to keep objects
2824 accessed frequently in memory to improve performance whilst low
2825 enough to keep larger objects from hoarding cache_mem.
2826 DOC_END
2827
2828 NAME: memory_cache_shared
2829 COMMENT: on|off
2830 TYPE: YesNoNone
2831 LOC: Config.memShared
2832 DEFAULT: none
2833 DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
2834 DOC_START
2835 Controls whether the memory cache is shared among SMP workers.
2836
2837 The shared memory cache is meant to occupy cache_mem bytes and replace
2838 the non-shared memory cache, although some entities may still be
2839 cached locally by workers for now (e.g., internal and in-transit
2840 objects may be served from a local memory cache even if shared memory
2841 caching is enabled).
2842
2843 By default, the memory cache is shared if and only if all of the
2844 following conditions are satisfied: Squid runs in SMP mode with
2845 multiple workers, cache_mem is positive, and Squid environment
2846 supports required IPC primitives (e.g., POSIX shared memory segments
2847 and GCC-style atomic operations).
2848
2849 To avoid blocking locks, shared memory uses opportunistic algorithms
2850 that do not guarantee that every cachable entity that could have been
2851 shared among SMP workers will actually be shared.
2852
2853 Currently, entities exceeding 32KB in size cannot be shared.
2854 DOC_END
2855
2856 NAME: memory_cache_mode
2857 TYPE: memcachemode
2858 LOC: Config
2859 DEFAULT: always
2860 DOC_START
2861 Controls which objects to keep in the memory cache (cache_mem)
2862
2863 always Keep most recently fetched objects in memory (default)
2864
2865 disk Only disk cache hits are kept in memory, which means
2866 an object must first be cached on disk and then hit
2867 a second time before cached in memory.
2868
2869 network Only objects fetched from network is kept in memory
2870 DOC_END
2871
2872 NAME: memory_replacement_policy
2873 TYPE: removalpolicy
2874 LOC: Config.memPolicy
2875 DEFAULT: lru
2876 DOC_START
2877 The memory replacement policy parameter determines which
2878 objects are purged from memory when memory space is needed.
2879
2880 See cache_replacement_policy for details.
2881 DOC_END
2882
2883 COMMENT_START
2884 DISK CACHE OPTIONS
2885 -----------------------------------------------------------------------------
2886 COMMENT_END
2887
2888 NAME: cache_replacement_policy
2889 TYPE: removalpolicy
2890 LOC: Config.replPolicy
2891 DEFAULT: lru
2892 DOC_START
2893 The cache replacement policy parameter determines which
2894 objects are evicted (replaced) when disk space is needed.
2895
2896 lru : Squid's original list based LRU policy
2897 heap GDSF : Greedy-Dual Size Frequency
2898 heap LFUDA: Least Frequently Used with Dynamic Aging
2899 heap LRU : LRU policy implemented using a heap
2900
2901 Applies to any cache_dir lines listed below this.
2902
2903 The LRU policies keeps recently referenced objects.
2904
2905 The heap GDSF policy optimizes object hit rate by keeping smaller
2906 popular objects in cache so it has a better chance of getting a
2907 hit. It achieves a lower byte hit rate than LFUDA though since
2908 it evicts larger (possibly popular) objects.
2909
2910 The heap LFUDA policy keeps popular objects in cache regardless of
2911 their size and thus optimizes byte hit rate at the expense of
2912 hit rate since one large, popular object will prevent many
2913 smaller, slightly less popular objects from being cached.
2914
2915 Both policies utilize a dynamic aging mechanism that prevents
2916 cache pollution that can otherwise occur with frequency-based
2917 replacement policies.
2918
2919 NOTE: if using the LFUDA replacement policy you should increase
2920 the value of maximum_object_size above its default of 4096 KB to
2921 to maximize the potential byte hit rate improvement of LFUDA.
2922
2923 For more information about the GDSF and LFUDA cache replacement
2924 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
2925 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
2926 DOC_END
2927
2928 NAME: cache_dir
2929 TYPE: cachedir
2930 DEFAULT: none
2931 LOC: Config.cacheSwap
2932 DOC_START
2933 Usage:
2934
2935 cache_dir Type Directory-Name Fs-specific-data [options]
2936
2937 You can specify multiple cache_dir lines to spread the
2938 cache among different disk partitions.
2939
2940 Type specifies the kind of storage system to use. Only "ufs"
2941 is built by default. To enable any of the other storage systems
2942 see the --enable-storeio configure option.
2943
2944 'Directory' is a top-level directory where cache swap
2945 files will be stored. If you want to use an entire disk
2946 for caching, this can be the mount-point directory.
2947 The directory must exist and be writable by the Squid
2948 process. Squid will NOT create this directory for you.
2949
2950 In SMP configurations, cache_dir must not precede the workers option
2951 and should use configuration macros or conditionals to give each
2952 worker interested in disk caching a dedicated cache directory.
2953
2954 The ufs store type:
2955
2956 "ufs" is the old well-known Squid storage format that has always
2957 been there.
2958
2959 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
2960
2961 'Mbytes' is the amount of disk space (MB) to use under this
2962 directory. The default is 100 MB. Change this to suit your
2963 configuration. Do NOT put the size of your disk drive here.
2964 Instead, if you want Squid to use the entire disk drive,
2965 subtract 20% and use that value.
2966
2967 'L1' is the number of first-level subdirectories which
2968 will be created under the 'Directory'. The default is 16.
2969
2970 'L2' is the number of second-level subdirectories which
2971 will be created under each first-level directory. The default
2972 is 256.
2973
2974 The aufs store type:
2975
2976 "aufs" uses the same storage format as "ufs", utilizing
2977 POSIX-threads to avoid blocking the main Squid process on
2978 disk-I/O. This was formerly known in Squid as async-io.
2979
2980 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
2981
2982 see argument descriptions under ufs above
2983
2984 The diskd store type:
2985
2986 "diskd" uses the same storage format as "ufs", utilizing a
2987 separate process to avoid blocking the main Squid process on
2988 disk-I/O.
2989
2990 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
2991
2992 see argument descriptions under ufs above
2993
2994 Q1 specifies the number of unacknowledged I/O requests when Squid
2995 stops opening new files. If this many messages are in the queues,
2996 Squid won't open new files. Default is 64
2997
2998 Q2 specifies the number of unacknowledged messages when Squid
2999 starts blocking. If this many messages are in the queues,
3000 Squid blocks until it receives some replies. Default is 72
3001
3002 When Q1 < Q2 (the default), the cache directory is optimized
3003 for lower response time at the expense of a decrease in hit
3004 ratio. If Q1 > Q2, the cache directory is optimized for
3005 higher hit ratio at the expense of an increase in response
3006 time.
3007
3008 The rock store type:
3009
3010 cache_dir rock Directory-Name Mbytes <max-size=bytes> [options]
3011
3012 The Rock Store type is a database-style storage. All cached
3013 entries are stored in a "database" file, using fixed-size slots,
3014 one entry per slot. The database size is specified in MB. The
3015 slot size is specified in bytes using the max-size option. See
3016 below for more info on the max-size option.
3017
3018 swap-timeout=msec: Squid will not start writing a miss to or
3019 reading a hit from disk if it estimates that the swap operation
3020 will take more than the specified number of milliseconds. By
3021 default and when set to zero, disables the disk I/O time limit
3022 enforcement. Ignored when using blocking I/O module because
3023 blocking synchronous I/O does not allow Squid to estimate the
3024 expected swap wait time.
3025
3026 max-swap-rate=swaps/sec: Artificially limits disk access using
3027 the specified I/O rate limit. Swap out requests that
3028 would cause the average I/O rate to exceed the limit are
3029 delayed. Individual swap in requests (i.e., hits or reads) are
3030 not delayed, but they do contribute to measured swap rate and
3031 since they are placed in the same FIFO queue as swap out
3032 requests, they may wait longer if max-swap-rate is smaller.
3033 This is necessary on file systems that buffer "too
3034 many" writes and then start blocking Squid and other processes
3035 while committing those writes to disk. Usually used together
3036 with swap-timeout to avoid excessive delays and queue overflows
3037 when disk demand exceeds available disk "bandwidth". By default
3038 and when set to zero, disables the disk I/O rate limit
3039 enforcement. Currently supported by IpcIo module only.
3040
3041
3042 The coss store type:
3043
3044 NP: COSS filesystem in Squid-3 has been deemed too unstable for
3045 production use and has thus been removed from this release.
3046 We hope that it can be made usable again soon.
3047
3048 block-size=n defines the "block size" for COSS cache_dir's.
3049 Squid uses file numbers as block numbers. Since file numbers
3050 are limited to 24 bits, the block size determines the maximum
3051 size of the COSS partition. The default is 512 bytes, which
3052 leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
3053 you should not change the coss block size after Squid
3054 has written some objects to the cache_dir.
3055
3056 The coss file store has changed from 2.5. Now it uses a file
3057 called 'stripe' in the directory names in the config - and
3058 this will be created by squid -z.
3059
3060 Common options:
3061
3062 no-store, no new objects should be stored to this cache_dir
3063
3064 min-size=n, refers to the min object size in bytes this cache_dir
3065 will accept. It's used to restrict a cache_dir to only store
3066 large objects (e.g. aufs) while other storedirs are optimized
3067 for smaller objects (e.g. COSS). Defaults to 0.
3068
3069 max-size=n, refers to the max object size in bytes this cache_dir
3070 supports. It is used to select the cache_dir to store the object.
3071 Note: To make optimal use of the max-size limits you should order
3072 the cache_dir lines with the smallest max-size value first and the
3073 ones with no max-size specification last.
3074
3075 Note for coss, max-size must be less than COSS_MEMBUF_SZ,
3076 which can be changed with the --with-coss-membuf-size=N configure
3077 option.
3078 NOCOMMENT_START
3079
3080 # Uncomment and adjust the following to add a disk cache directory.
3081 #cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
3082 NOCOMMENT_END
3083 DOC_END
3084
3085 NAME: store_dir_select_algorithm
3086 TYPE: string
3087 LOC: Config.store_dir_select_algorithm
3088 DEFAULT: least-load
3089 DOC_START
3090 Set this to 'round-robin' as an alternative.
3091 DOC_END
3092
3093 NAME: max_open_disk_fds
3094 TYPE: int
3095 LOC: Config.max_open_disk_fds
3096 DEFAULT: 0
3097 DOC_START
3098 To avoid having disk as the I/O bottleneck Squid can optionally
3099 bypass the on-disk cache if more than this amount of disk file
3100 descriptors are open.
3101
3102 A value of 0 indicates no limit.
3103 DOC_END
3104
3105 NAME: minimum_object_size
3106 COMMENT: (bytes)
3107 TYPE: b_int64_t
3108 DEFAULT: 0 KB
3109 LOC: Config.Store.minObjectSize
3110 DOC_START
3111 Objects smaller than this size will NOT be saved on disk. The
3112 value is specified in kilobytes, and the default is 0 KB, which
3113 means there is no minimum.
3114 DOC_END
3115
3116 NAME: maximum_object_size
3117 COMMENT: (bytes)
3118 TYPE: b_int64_t
3119 DEFAULT: 4096 KB
3120 LOC: Config.Store.maxObjectSize
3121 DOC_START
3122 Objects larger than this size will NOT be saved on disk. The
3123 value is specified in kilobytes, and the default is 4MB. If
3124 you wish to get a high BYTES hit ratio, you should probably
3125 increase this (one 32 MB object hit counts for 3200 10KB
3126 hits). If you wish to increase speed more than your want to
3127 save bandwidth you should leave this low.
3128
3129 NOTE: if using the LFUDA replacement policy you should increase
3130 this value to maximize the byte hit rate improvement of LFUDA!
3131 See replacement_policy below for a discussion of this policy.
3132 DOC_END
3133
3134 NAME: cache_swap_low
3135 COMMENT: (percent, 0-100)
3136 TYPE: int
3137 DEFAULT: 90
3138 LOC: Config.Swap.lowWaterMark
3139 DOC_NONE
3140
3141 NAME: cache_swap_high
3142 COMMENT: (percent, 0-100)
3143 TYPE: int
3144 DEFAULT: 95
3145 LOC: Config.Swap.highWaterMark
3146 DOC_START
3147
3148 The low- and high-water marks for cache object replacement.
3149 Replacement begins when the swap (disk) usage is above the
3150 low-water mark and attempts to maintain utilization near the
3151 low-water mark. As swap utilization gets close to high-water
3152 mark object eviction becomes more aggressive. If utilization is
3153 close to the low-water mark less replacement is done each time.
3154
3155 Defaults are 90% and 95%. If you have a large cache, 5% could be
3156 hundreds of MB. If this is the case you may wish to set these
3157 numbers closer together.
3158 DOC_END
3159
3160 COMMENT_START
3161 LOGFILE OPTIONS
3162 -----------------------------------------------------------------------------
3163 COMMENT_END
3164
3165 NAME: logformat
3166 TYPE: logformat
3167 LOC: Log::TheConfig
3168 DEFAULT: none
3169 DOC_START
3170 Usage:
3171
3172 logformat <name> <format specification>
3173
3174 Defines an access log format.
3175
3176 The <format specification> is a string with embedded % format codes
3177
3178 % format codes all follow the same basic structure where all but
3179 the formatcode is optional. Output strings are automatically escaped
3180 as required according to their context and the output format
3181 modifiers are usually not needed, but can be specified if an explicit
3182 output format is desired.
3183
3184 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3185
3186 " output in quoted string format
3187 [ output in squid text log format as used by log_mime_hdrs
3188 # output in URL quoted format
3189 ' output as-is
3190
3191 - left aligned
3192
3193 width minimum and/or maximum field width:
3194 [width_min][.width_max]
3195 When minimum starts with 0, the field is zero-padded.
3196 String values exceeding maximum width are truncated.
3197
3198 {arg} argument such as header name etc
3199
3200 Format codes:
3201
3202 % a literal % character
3203 sn Unique sequence number per log line entry
3204 err_code The ID of an error response served by Squid or
3205 a similar internal error identifier.
3206 err_detail Additional err_code-dependent error information.
3207
3208 Connection related format codes:
3209
3210 >a Client source IP address
3211 >A Client FQDN
3212 >p Client source port
3213 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3214 >la Local IP address the client connected to
3215 >lp Local port number the client connected to
3216
3217 la Local listening IP address the client connection was connected to.
3218 lp Local listening port number the client connection was connected to.
3219
3220 <a Server IP address of the last server or peer connection
3221 <A Server FQDN or peer name
3222 <p Server port number of the last server or peer connection
3223 <la Local IP address of the last server or peer connection
3224 <lp Local port number of the last server or peer connection
3225
3226 Time related format codes:
3227
3228 ts Seconds since epoch
3229 tu subsecond time (milliseconds)
3230 tl Local time. Optional strftime format argument
3231 default %d/%b/%Y:%H:%M:%S %z
3232 tg GMT time. Optional strftime format argument
3233 default %d/%b/%Y:%H:%M:%S %z
3234 tr Response time (milliseconds)
3235 dt Total time spent making DNS lookups (milliseconds)
3236
3237 Access Control related format codes:
3238
3239 et Tag returned by external acl
3240 ea Log string returned by external acl
3241 un User name (any available)
3242 ul User name from authentication
3243 ue User name from external acl helper
3244 ui User name from ident
3245 us User name from SSL
3246
3247 HTTP related format codes:
3248
3249 [http::]>h Original request header. Optional header name argument
3250 on the format header[:[separator]element]
3251 [http::]>ha The HTTP request headers after adaptation and redirection.
3252 Optional header name argument as for >h
3253 [http::]<h Reply header. Optional header name argument
3254 as for >h
3255 [http::]>Hs HTTP status code sent to the client
3256 [http::]<Hs HTTP status code received from the next hop
3257 [http::]<bs Number of HTTP-equivalent message body bytes
3258 received from the next hop, excluding chunked
3259 transfer encoding and control messages.
3260 Generated FTP/Gopher listings are treated as
3261 received bodies.
3262 [http::]mt MIME content type
3263 [http::]rm Request method (GET/POST etc)
3264 [http::]>rm Request method from client
3265 [http::]<rm Request method sent to server or peer
3266 [http::]ru Request URL from client (historic, filtered for logging)
3267 [http::]>ru Request URL from client
3268 [http::]<ru Request URL sent to server or peer
3269 [http::]rp Request URL-Path excluding hostname
3270 [http::]>rp Request URL-Path excluding hostname from client
3271 [http::]<rp Request URL-Path excluding hostname sento to server or peer
3272 [http::]rv Request protocol version
3273 [http::]>rv Request protocol version from client
3274 [http::]<rv Request protocol version sent to server or peer
3275 [http::]<st Sent reply size including HTTP headers
3276 [http::]>st Received request size including HTTP headers. In the
3277 case of chunked requests the chunked encoding metadata
3278 are not included
3279 [http::]>sh Received HTTP request headers size
3280 [http::]<sh Sent HTTP reply headers size
3281 [http::]st Request+Reply size including HTTP headers
3282 [http::]<sH Reply high offset sent
3283 [http::]<sS Upstream object size
3284 [http::]<pt Peer response time in milliseconds. The timer starts
3285 when the last request byte is sent to the next hop
3286 and stops when the last response byte is received.
3287 [http::]<tt Total server-side time in milliseconds. The timer
3288 starts with the first connect request (or write I/O)
3289 sent to the first selected peer. The timer stops
3290 with the last I/O with the last peer.
3291
3292 Squid handling related format codes:
3293
3294 Ss Squid request status (TCP_MISS etc)
3295 Sh Squid hierarchy status (DEFAULT_PARENT etc)
3296
3297 If ICAP is enabled, the following code becomes available (as
3298 well as ICAP log codes documented with the icap_log option):
3299
3300 icap::tt Total ICAP processing time for the HTTP
3301 transaction. The timer ticks when ICAP
3302 ACLs are checked and when ICAP
3303 transaction is in progress.
3304
3305 If adaptation is enabled the following three codes become available:
3306
3307 adapt::<last_h The header of the last ICAP response or
3308 meta-information from the last eCAP
3309 transaction related to the HTTP transaction.
3310 Like <h, accepts an optional header name
3311 argument.
3312
3313 adapt::sum_trs Summed adaptation transaction response
3314 times recorded as a comma-separated list in
3315 the order of transaction start time. Each time
3316 value is recorded as an integer number,
3317 representing response time of one or more
3318 adaptation (ICAP or eCAP) transaction in
3319 milliseconds. When a failed transaction is
3320 being retried or repeated, its time is not
3321 logged individually but added to the
3322 replacement (next) transaction. See also:
3323 adapt::all_trs.
3324
3325 adapt::all_trs All adaptation transaction response times.
3326 Same as adaptation_strs but response times of
3327 individual transactions are never added
3328 together. Instead, all transaction response
3329 times are recorded individually.
3330
3331 You can prefix adapt::*_trs format codes with adaptation
3332 service name in curly braces to record response time(s) specific
3333 to that service. For example: %{my_service}adapt::sum_trs
3334
3335 The default formats available (which do not need re-defining) are:
3336
3337 logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
3338 logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
3339 logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
3340 logformat referrer %ts.%03tu %>a %{Referer}>h %ru
3341 logformat useragent %>a [%tl] "%{User-Agent}>h"
3342
3343 NOTE: When the log_mime_hdrs directive is set to ON.
3344 The squid, common and combined formats have a safely encoded copy
3345 of the mime headers appended to each line within a pair of brackets.
3346
3347 NOTE: The common and combined formats are not quite true to the Apache definition.
3348 The logs from Squid contain an extra status and hierarchy code appended.
3349
3350 DOC_END
3351
3352 NAME: access_log cache_access_log
3353 TYPE: access_log
3354 LOC: Config.Log.accesslogs
3355 DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
3356 DOC_START
3357 These files log client request activities. Has a line every HTTP or
3358 ICP request. The format is:
3359 access_log <module>:<place> [<logformat name> [acl acl ...]]
3360 access_log none [acl acl ...]]
3361
3362 Will log to the specified module:place using the specified format (which
3363 must be defined in a logformat directive) those entries which match
3364 ALL the acl's specified (which must be defined in acl clauses).
3365 If no acl is specified, all requests will be logged to this destination.
3366
3367 ===== Modules Currently available =====
3368
3369 none Do not log any requests matching these ACL.
3370 Do not specify Place or logformat name.
3371
3372 stdio Write each log line to disk immediately at the completion of
3373 each request.
3374 Place: the filename and path to be written.
3375
3376 daemon Very similar to stdio. But instead of writing to disk the log
3377 line is passed to a daemon helper for asychronous handling instead.
3378 Place: varies depending on the daemon.
3379
3380 log_file_daemon Place: the file name and path to be written.
3381
3382 syslog To log each request via syslog facility.
3383 Place: The syslog facility and priority level for these entries.
3384 Place Format: facility.priority
3385
3386 where facility could be any of:
3387 authpriv, daemon, local0 ... local7 or user.
3388
3389 And priority could be any of:
3390 err, warning, notice, info, debug.
3391
3392 udp To send each log line as text data to a UDP receiver.
3393 Place: The destination host name or IP and port.
3394 Place Format: //host:port
3395
3396 tcp To send each log line as text data to a TCP receiver.
3397 Place: The destination host name or IP and port.
3398 Place Format: //host:port
3399
3400 Default:
3401 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
3402 DOC_END
3403
3404 NAME: icap_log
3405 TYPE: access_log
3406 IFDEF: ICAP_CLIENT
3407 LOC: Config.Log.icaplogs
3408 DEFAULT: none
3409 DOC_START
3410 ICAP log files record ICAP transaction summaries, one line per
3411 transaction.
3412
3413 The icap_log option format is:
3414 icap_log <filepath> [<logformat name> [acl acl ...]]
3415 icap_log none [acl acl ...]]
3416
3417 Please see access_log option documentation for details. The two
3418 kinds of logs share the overall configuration approach and many
3419 features.
3420
3421 ICAP processing of a single HTTP message or transaction may
3422 require multiple ICAP transactions. In such cases, multiple
3423 ICAP transaction log lines will correspond to a single access
3424 log line.
3425
3426 ICAP log uses logformat codes that make sense for an ICAP
3427 transaction. Header-related codes are applied to the HTTP header
3428 embedded in an ICAP server response, with the following caveats:
3429 For REQMOD, there is no HTTP response header unless the ICAP
3430 server performed request satisfaction. For RESPMOD, the HTTP
3431 request header is the header sent to the ICAP server. For
3432 OPTIONS, there are no HTTP headers.
3433
3434 The following format codes are also available for ICAP logs:
3435
3436 icap::<A ICAP server IP address. Similar to <A.
3437
3438 icap::<service_name ICAP service name from the icap_service
3439 option in Squid configuration file.
3440
3441 icap::ru ICAP Request-URI. Similar to ru.
3442
3443 icap::rm ICAP request method (REQMOD, RESPMOD, or
3444 OPTIONS). Similar to existing rm.
3445
3446 icap::>st Bytes sent to the ICAP server (TCP payload
3447 only; i.e., what Squid writes to the socket).
3448
3449 icap::<st Bytes received from the ICAP server (TCP
3450 payload only; i.e., what Squid reads from
3451 the socket).
3452
3453 icap::<bs Number of message body bytes received from the
3454 ICAP server. ICAP message body, if any, usually
3455 includes encapsulated HTTP message headers and
3456 possibly encapsulated HTTP message body. The
3457 HTTP body part is dechunked before its size is
3458 computed.
3459
3460 icap::tr Transaction response time (in
3461 milliseconds). The timer starts when
3462 the ICAP transaction is created and
3463 stops when the transaction is completed.
3464 Similar to tr.
3465
3466 icap::tio Transaction I/O time (in milliseconds). The
3467 timer starts when the first ICAP request
3468 byte is scheduled for sending. The timers
3469 stops when the last byte of the ICAP response
3470 is received.
3471
3472 icap::to Transaction outcome: ICAP_ERR* for all
3473 transaction errors, ICAP_OPT for OPTION
3474 transactions, ICAP_ECHO for 204
3475 responses, ICAP_MOD for message
3476 modification, and ICAP_SAT for request
3477 satisfaction. Similar to Ss.
3478
3479 icap::Hs ICAP response status code. Similar to Hs.
3480
3481 icap::>h ICAP request header(s). Similar to >h.
3482
3483 icap::<h ICAP response header(s). Similar to <h.
3484
3485 The default ICAP log format, which can be used without an explicit
3486 definition, is called icap_squid:
3487
3488 logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
3489
3490 See also: logformat, log_icap, and %adapt::<last_h
3491 DOC_END
3492
3493 NAME: logfile_daemon
3494 TYPE: string
3495 DEFAULT: @DEFAULT_LOGFILED@
3496 LOC: Log::TheConfig.logfile_daemon
3497 DOC_START
3498 Specify the path to the logfile-writing daemon. This daemon is
3499 used to write the access and store logs, if configured.
3500
3501 Squid sends a number of commands to the log daemon:
3502 L<data>\n - logfile data
3503 R\n - rotate file
3504 T\n - truncate file
3505 O\n - reopen file
3506 F\n - flush file
3507 r<n>\n - set rotate count to <n>
3508 b<n>\n - 1 = buffer output, 0 = don't buffer output
3509
3510 No responses is expected.
3511 DOC_END
3512
3513 NAME: log_access
3514 TYPE: acl_access
3515 LOC: Config.accessList.log
3516 DEFAULT: none
3517 COMMENT: allow|deny acl acl...
3518 DOC_START
3519 This options allows you to control which requests gets logged
3520 to access.log (see access_log directive). Requests denied for
3521 logging will also not be accounted for in performance counters.
3522
3523 This clause only supports fast acl types.
3524 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3525 DOC_END
3526
3527 NAME: log_icap
3528 TYPE: acl_access
3529 IFDEF: ICAP_CLIENT
3530 LOC: Config.accessList.icap
3531 DEFAULT: none
3532 DOC_START
3533 This options allows you to control which requests get logged
3534 to icap.log. See the icap_log directive for ICAP log details.
3535 DOC_END
3536
3537 NAME: cache_store_log
3538 TYPE: string
3539 DEFAULT: none
3540 LOC: Config.Log.store
3541 DOC_START
3542 Logs the activities of the storage manager. Shows which
3543 objects are ejected from the cache, and which objects are
3544 saved and for how long. To disable, enter "none" or remove the line.
3545 There are not really utilities to analyze this data, so you can safely
3546 disable it.
3547
3548 Example:
3549 cache_store_log @DEFAULT_STORE_LOG@
3550 DOC_END
3551
3552 NAME: cache_swap_state cache_swap_log
3553 TYPE: string
3554 LOC: Config.Log.swap
3555 DEFAULT: none
3556 DOC_START
3557 Location for the cache "swap.state" file. This index file holds
3558 the metadata of objects saved on disk. It is used to rebuild
3559 the cache during startup. Normally this file resides in each
3560 'cache_dir' directory, but you may specify an alternate
3561 pathname here. Note you must give a full filename, not just
3562 a directory. Since this is the index for the whole object
3563 list you CANNOT periodically rotate it!
3564
3565 If %s can be used in the file name it will be replaced with a
3566 a representation of the cache_dir name where each / is replaced
3567 with '.'. This is needed to allow adding/removing cache_dir
3568 lines when cache_swap_log is being used.
3569
3570 If have more than one 'cache_dir', and %s is not used in the name
3571 these swap logs will have names such as:
3572
3573 cache_swap_log.00
3574 cache_swap_log.01
3575 cache_swap_log.02
3576
3577 The numbered extension (which is added automatically)
3578 corresponds to the order of the 'cache_dir' lines in this
3579 configuration file. If you change the order of the 'cache_dir'
3580 lines in this file, these index files will NOT correspond to
3581 the correct 'cache_dir' entry (unless you manually rename
3582 them). We recommend you do NOT use this option. It is
3583 better to keep these index files in each 'cache_dir' directory.
3584 DOC_END
3585
3586 NAME: logfile_rotate
3587 TYPE: int
3588 DEFAULT: 10
3589 LOC: Config.Log.rotateNumber
3590 DOC_START
3591 Specifies the number of logfile rotations to make when you
3592 type 'squid -k rotate'. The default is 10, which will rotate
3593 with extensions 0 through 9. Setting logfile_rotate to 0 will
3594 disable the file name rotation, but the logfiles are still closed
3595 and re-opened. This will enable you to rename the logfiles
3596 yourself just before sending the rotate signal.
3597
3598 Note, the 'squid -k rotate' command normally sends a USR1
3599 signal to the running squid process. In certain situations
3600 (e.g. on Linux with Async I/O), USR1 is used for other
3601 purposes, so -k rotate uses another signal. It is best to get
3602 in the habit of using 'squid -k rotate' instead of 'kill -USR1
3603 <pid>'.
3604
3605 Note, from Squid-3.1 this option has no effect on the cache.log,
3606 that log can be rotated separately by using debug_options
3607 DOC_END
3608
3609 NAME: emulate_httpd_log
3610 TYPE: obsolete
3611 DOC_START
3612 Replace this with an access_log directive using the format 'common' or 'combined'.
3613 DOC_END
3614
3615 NAME: log_ip_on_direct
3616 TYPE: obsolete
3617 DOC_START
3618 Remove this option from your config. To log server or peer names use %<A in the log format.
3619 DOC_END
3620
3621 NAME: mime_table
3622 TYPE: string
3623 DEFAULT: @DEFAULT_MIME_TABLE@
3624 LOC: Config.mimeTablePathname
3625 DOC_START
3626 Pathname to Squid's MIME table. You shouldn't need to change
3627 this, but the default file contains examples and formatting
3628 information if you do.
3629 DOC_END
3630
3631 NAME: log_mime_hdrs
3632 COMMENT: on|off
3633 TYPE: onoff
3634 LOC: Config.onoff.log_mime_hdrs
3635 DEFAULT: off
3636 DOC_START
3637 The Cache can record both the request and the response MIME
3638 headers for each HTTP transaction. The headers are encoded
3639 safely and will appear as two bracketed fields at the end of
3640 the access log (for either the native or httpd-emulated log
3641 formats). To enable this logging set log_mime_hdrs to 'on'.
3642 DOC_END
3643
3644 NAME: useragent_log
3645 TYPE: obsolete
3646 DOC_START
3647 Replace this with an access_log directive using the format 'useragent'.
3648 DOC_END
3649
3650 NAME: referer_log referrer_log
3651 TYPE: obsolete
3652 DOC_START
3653 Replace this with an access_log directive using the format 'referrer'.
3654 DOC_END
3655
3656 NAME: pid_filename
3657 TYPE: string
3658 DEFAULT: @DEFAULT_PID_FILE@
3659 LOC: Config.pidFilename
3660 DOC_START
3661 A filename to write the process-id to. To disable, enter "none".
3662 DOC_END
3663
3664 NAME: log_fqdn
3665 TYPE: obsolete
3666 DOC_START
3667 Remove this option from your config. To log FQDN use %>A in the log format.
3668 DOC_END
3669
3670 NAME: client_netmask
3671 TYPE: address
3672 LOC: Config.Addrs.client_netmask
3673 DEFAULT: no_addr
3674 DOC_START
3675 A netmask for client addresses in logfiles and cachemgr output.
3676 Change this to protect the privacy of your cache clients.
3677 A netmask of 255.255.255.0 will log all IP's in that range with
3678 the last digit set to '0'.
3679 DOC_END
3680
3681 NAME: forward_log
3682 TYPE: obsolete
3683 DOC_START
3684 Use a regular access.log with ACL limiting it to MISS events.
3685 DOC_END
3686
3687 NAME: strip_query_terms
3688 TYPE: onoff
3689 LOC: Config.onoff.strip_query_terms
3690 DEFAULT: on
3691 DOC_START
3692 By default, Squid strips query terms from requested URLs before
3693 logging. This protects your user's privacy.
3694 DOC_END
3695
3696 NAME: buffered_logs
3697 COMMENT: on|off
3698 TYPE: onoff
3699 DEFAULT: off
3700 LOC: Config.onoff.buffered_logs
3701 DOC_START
3702 cache.log log file is written with stdio functions, and as such
3703 it can be buffered or unbuffered. By default it will be unbuffered.
3704 Buffering it can speed up the writing slightly (though you are
3705 unlikely to need to worry unless you run with tons of debugging
3706 enabled in which case performance will suffer badly anyway..).
3707 DOC_END
3708
3709 NAME: netdb_filename
3710 TYPE: string
3711 DEFAULT: stdio:@DEFAULT_NETDB_FILE@
3712 LOC: Config.netdbFilename
3713 IFDEF: USE_ICMP
3714 DOC_START
3715 A filename where Squid stores it's netdb state between restarts.
3716 To disable, enter "none".
3717 DOC_END
3718
3719 COMMENT_START
3720 OPTIONS FOR TROUBLESHOOTING
3721 -----------------------------------------------------------------------------
3722 COMMENT_END
3723
3724 NAME: cache_log
3725 TYPE: string
3726 DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
3727 LOC: Debug::cache_log
3728 DOC_START
3729 Cache logging file. This is where general information about
3730 your cache's behavior goes. You can increase the amount of data
3731 logged to this file and how often its rotated with "debug_options"
3732 DOC_END
3733
3734 NAME: debug_options
3735 TYPE: eol
3736 DEFAULT: ALL,1
3737 LOC: Debug::debugOptions
3738 DOC_START
3739 Logging options are set as section,level where each source file
3740 is assigned a unique section. Lower levels result in less
3741 output, Full debugging (level 9) can result in a very large
3742 log file, so be careful.
3743
3744 The magic word "ALL" sets debugging levels for all sections.
3745 We recommend normally running with "ALL,1".
3746
3747 The rotate=N option can be used to keep more or less of these logs
3748 than would otherwise be kept by logfile_rotate.
3749 For most uses a single log should be enough to monitor current
3750 events affecting Squid.
3751 DOC_END
3752
3753 NAME: coredump_dir
3754 TYPE: string
3755 LOC: Config.coredump_dir
3756 DEFAULT_IF_NONE: none
3757 DOC_START
3758 By default Squid leaves core files in the directory from where
3759 it was started. If you set 'coredump_dir' to a directory
3760 that exists, Squid will chdir() to that directory at startup
3761 and coredump files will be left there.
3762
3763 NOCOMMENT_START
3764
3765 # Leave coredumps in the first cache dir
3766 coredump_dir @DEFAULT_SWAP_DIR@
3767 NOCOMMENT_END
3768 DOC_END
3769
3770
3771 COMMENT_START
3772 OPTIONS FOR FTP GATEWAYING
3773 -----------------------------------------------------------------------------
3774 COMMENT_END
3775
3776 NAME: ftp_user
3777 TYPE: string
3778 DEFAULT: Squid@
3779 LOC: Config.Ftp.anon_user
3780 DOC_START
3781 If you want the anonymous login password to be more informative
3782 (and enable the use of picky ftp servers), set this to something
3783 reasonable for your domain, like wwwuser@somewhere.net
3784
3785 The reason why this is domainless by default is the
3786 request can be made on the behalf of a user in any domain,
3787 depending on how the cache is used.
3788 Some ftp server also validate the email address is valid
3789 (for example perl.com).
3790 DOC_END
3791
3792 NAME: ftp_passive
3793 TYPE: onoff
3794 DEFAULT: on
3795 LOC: Config.Ftp.passive
3796 DOC_START
3797 If your firewall does not allow Squid to use passive
3798 connections, turn off this option.
3799
3800 Use of ftp_epsv_all option requires this to be ON.
3801 DOC_END
3802
3803 NAME: ftp_epsv_all
3804 TYPE: onoff
3805 DEFAULT: off
3806 LOC: Config.Ftp.epsv_all
3807 DOC_START
3808 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
3809
3810 NATs may be able to put the connection on a "fast path" through the
3811 translator, as the EPRT command will never be used and therefore,
3812 translation of the data portion of the segments will never be needed.
3813
3814 When a client only expects to do two-way FTP transfers this may be
3815 useful.
3816 If squid finds that it must do a three-way FTP transfer after issuing
3817 an EPSV ALL command, the FTP session will fail.
3818
3819 If you have any doubts about this option do not use it.
3820 Squid will nicely attempt all other connection methods.
3821
3822 Requires ftp_passive to be ON (default) for any effect.
3823 DOC_END
3824
3825 NAME: ftp_epsv
3826 TYPE: onoff
3827 DEFAULT: on
3828 LOC: Config.Ftp.epsv
3829 DOC_START
3830 FTP Protocol extensions permit the use of a special "EPSV" command.
3831
3832 NATs may be able to put the connection on a "fast path" through the
3833 translator using EPSV, as the EPRT command will never be used
3834 and therefore, translation of the data portion of the segments
3835 will never be needed.
3836
3837 Turning this OFF will prevent EPSV being attempted.
3838 WARNING: Doing so will convert Squid back to the old behavior with all
3839 the related problems with external NAT devices/layers.
3840
3841 Requires ftp_passive to be ON (default) for any effect.
3842 DOC_END
3843
3844 NAME: ftp_eprt
3845 TYPE: onoff
3846 DEFAULT: on
3847 LOC: Config.Ftp.eprt
3848 DOC_START
3849 FTP Protocol extensions permit the use of a special "EPRT" command.
3850
3851 This extension provides a protocol neutral alternative to the
3852 IPv4-only PORT command. When supported it enables active FTP data
3853 channels over IPv6 and efficient NAT handling.
3854
3855 Turning this OFF will prevent EPRT being attempted and will skip
3856 straight to using PORT for IPv4 servers.
3857
3858 Some devices are known to not handle this extension correctly and
3859 may result in crashes. Devices which suport EPRT enough to fail
3860 cleanly will result in Squid attempting PORT anyway. This directive
3861 should only be disabled when EPRT results in device failures.
3862
3863 WARNING: Doing so will convert Squid back to the old behavior with all
3864 the related problems with external NAT devices/layers and IPv4-only FTP.
3865 DOC_END
3866
3867 NAME: ftp_sanitycheck
3868 TYPE: onoff
3869 DEFAULT: on
3870 LOC: Config.Ftp.sanitycheck
3871 DOC_START
3872 For security and data integrity reasons Squid by default performs
3873 sanity checks of the addresses of FTP data connections ensure the
3874 data connection is to the requested server. If you need to allow
3875 FTP connections to servers using another IP address for the data
3876 connection turn this off.
3877 DOC_END
3878
3879 NAME: ftp_telnet_protocol
3880 TYPE: onoff
3881 DEFAULT: on
3882 LOC: Config.Ftp.telnet
3883 DOC_START
3884 The FTP protocol is officially defined to use the telnet protocol
3885 as transport channel for the control connection. However, many
3886 implementations are broken and does not respect this aspect of
3887 the FTP protocol.
3888
3889 If you have trouble accessing files with ASCII code 255 in the
3890 path or similar problems involving this ASCII code you can
3891 try setting this directive to off. If that helps, report to the
3892 operator of the FTP server in question that their FTP server
3893 is broken and does not follow the FTP standard.
3894 DOC_END
3895
3896 COMMENT_START
3897 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
3898 -----------------------------------------------------------------------------
3899 COMMENT_END
3900
3901 NAME: diskd_program
3902 TYPE: string
3903 DEFAULT: @DEFAULT_DISKD@
3904 LOC: Config.Program.diskd
3905 DOC_START
3906 Specify the location of the diskd executable.
3907 Note this is only useful if you have compiled in
3908 diskd as one of the store io modules.
3909 DOC_END
3910
3911 NAME: unlinkd_program
3912 IFDEF: USE_UNLINKD
3913 TYPE: string
3914 DEFAULT: @DEFAULT_UNLINKD@
3915 LOC: Config.Program.unlinkd
3916 DOC_START
3917 Specify the location of the executable for file deletion process.
3918 DOC_END
3919
3920 NAME: pinger_program
3921 TYPE: string
3922 DEFAULT: @DEFAULT_PINGER@
3923 LOC: Config.pinger.program
3924 IFDEF: USE_ICMP
3925 DOC_START
3926 Specify the location of the executable for the pinger process.
3927 DOC_END
3928
3929 NAME: pinger_enable
3930 TYPE: onoff
3931 DEFAULT: on
3932 LOC: Config.pinger.enable
3933 IFDEF: USE_ICMP
3934 DOC_START
3935 Control whether the pinger is active at run-time.
3936 Enables turning ICMP pinger on and off with a simple
3937 squid -k reconfigure.
3938 DOC_END
3939
3940
3941 COMMENT_START
3942 OPTIONS FOR URL REWRITING
3943 -----------------------------------------------------------------------------
3944 COMMENT_END
3945
3946 NAME: url_rewrite_program redirect_program
3947 TYPE: wordlist
3948 LOC: Config.Program.redirect
3949 DEFAULT: none
3950 DOC_START
3951 Specify the location of the executable URL rewriter to use.
3952 Since they can perform almost any function there isn't one included.
3953
3954 For each requested URL, the rewriter will receive on line with the format
3955
3956 URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
3957
3958 In the future, the rewriter interface will be extended with
3959 key=value pairs ("kvpairs" shown above). Rewriter programs
3960 should be prepared to receive and possibly ignore additional
3961 whitespace-separated tokens on each input line.
3962
3963 And the rewriter may return a rewritten URL. The other components of
3964 the request line does not need to be returned (ignored if they are).
3965
3966 The rewriter can also indicate that a client-side redirect should
3967 be performed to the new URL. This is done by prefixing the returned
3968 URL with "301:" (moved permanently) or 302: (moved temporarily), etc.
3969
3970 By default, a URL rewriter is not used.
3971 DOC_END
3972
3973 NAME: url_rewrite_children redirect_children
3974 TYPE: HelperChildConfig
3975 DEFAULT: 20 startup=0 idle=1 concurrency=0
3976 LOC: Config.redirectChildren
3977 DOC_START
3978 The maximum number of redirector processes to spawn. If you limit
3979 it too few Squid will have to wait for them to process a backlog of
3980 URLs, slowing it down. If you allow too many they will use RAM
3981 and other system resources noticably.
3982
3983 The startup= and idle= options allow some measure of skew in your
3984 tuning.
3985
3986 startup=
3987
3988 Sets a minimum of how many processes are to be spawned when Squid
3989 starts or reconfigures. When set to zero the first request will
3990 cause spawning of the first child process to handle it.
3991
3992 Starting too few will cause an initial slowdown in traffic as Squid
3993 attempts to simultaneously spawn enough processes to cope.
3994
3995 idle=
3996
3997 Sets a minimum of how many processes Squid is to try and keep available
3998 at all times. When traffic begins to rise above what the existing
3999 processes can handle this many more will be spawned up to the maximum
4000 configured. A minimum setting of 1 is required.
4001
4002 concurrency=
4003
4004 The number of requests each redirector helper can handle in
4005 parallel. Defaults to 0 which indicates the redirector
4006 is a old-style single threaded redirector.
4007
4008 When this directive is set to a value >= 1 then the protocol
4009 used to communicate with the helper is modified to include
4010 a request ID in front of the request/response. The request
4011 ID from the request must be echoed back with the response
4012 to that request.
4013 DOC_END
4014
4015 NAME: url_rewrite_host_header redirect_rewrites_host_header
4016 TYPE: onoff
4017 DEFAULT: on
4018 LOC: Config.onoff.redir_rewrites_host
4019 DOC_START
4020 To preserve same-origin security policies in browsers and
4021 prevent Host: header forgery by redirectors Squid rewrites
4022 any Host: header in redirected requests.
4023
4024 If you are running an accelerator this may not be a wanted
4025 effect of a redirector. This directive enables you disable
4026 Host: alteration in reverse-proxy traffic.
4027
4028 WARNING: Entries are cached on the result of the URL rewriting
4029 process, so be careful if you have domain-virtual hosts.
4030
4031 WARNING: Squid and other software verifies the URL and Host
4032 are matching, so be careful not to relay through other proxies
4033 or inspecting firewalls with this disabled.
4034 DOC_END
4035
4036 NAME: url_rewrite_access redirector_access
4037 TYPE: acl_access
4038 DEFAULT: none
4039 LOC: Config.accessList.redirector
4040 DOC_START
4041 If defined, this access list specifies which requests are
4042 sent to the redirector processes. By default all requests
4043 are sent.
4044
4045 This clause supports both fast and slow acl types.
4046 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4047 DOC_END
4048
4049 NAME: url_rewrite_bypass redirector_bypass
4050 TYPE: onoff
4051 LOC: Config.onoff.redirector_bypass
4052 DEFAULT: off
4053 DOC_START
4054 When this is 'on', a request will not go through the
4055 redirector if all redirectors are busy. If this is 'off'
4056 and the redirector queue grows too large, Squid will exit
4057 with a FATAL error and ask you to increase the number of
4058 redirectors. You should only enable this if the redirectors
4059 are not critical to your caching system. If you use
4060 redirectors for access control, and you enable this option,
4061 users may have access to pages they should not
4062 be allowed to request.
4063 DOC_END
4064
4065 COMMENT_START
4066 OPTIONS FOR TUNING THE CACHE
4067 -----------------------------------------------------------------------------
4068 COMMENT_END
4069
4070 NAME: cache no_cache
4071 TYPE: acl_access
4072 DEFAULT: none
4073 LOC: Config.accessList.noCache
4074 DOC_START
4075 A list of ACL elements which, if matched and denied, cause the request to
4076 not be satisfied from the cache and the reply to not be cached.
4077 In other words, use this to force certain objects to never be cached.
4078
4079 You must use the words 'allow' or 'deny' to indicate whether items
4080 matching the ACL should be allowed or denied into the cache.
4081
4082 Default is to allow all to be cached.
4083
4084 This clause supports both fast and slow acl types.
4085 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4086 DOC_END
4087
4088 NAME: max_stale
4089 COMMENT: time-units
4090 TYPE: time_t
4091 LOC: Config.maxStale
4092 DEFAULT: 1 week
4093 DOC_START
4094 This option puts an upper limit on how stale content Squid
4095 will serve from the cache if cache validation fails.
4096 Can be overriden by the refresh_pattern max-stale option.
4097 DOC_END
4098
4099 NAME: refresh_pattern
4100 TYPE: refreshpattern
4101 LOC: Config.Refresh
4102 DEFAULT: none
4103 DOC_START
4104 usage: refresh_pattern [-i] regex min percent max [options]
4105
4106 By default, regular expressions are CASE-SENSITIVE. To make
4107 them case-insensitive, use the -i option.
4108
4109 'Min' is the time (in minutes) an object without an explicit
4110 expiry time should be considered fresh. The recommended
4111 value is 0, any higher values may cause dynamic applications
4112 to be erroneously cached unless the application designer
4113 has taken the appropriate actions.
4114
4115 'Percent' is a percentage of the objects age (time since last
4116 modification age) an object without explicit expiry time
4117 will be considered fresh.
4118
4119 'Max' is an upper limit on how long objects without an explicit
4120 expiry time will be considered fresh.
4121
4122 options: override-expire
4123 override-lastmod
4124 reload-into-ims
4125 ignore-reload
4126 ignore-no-cache
4127 ignore-no-store
4128 ignore-must-revalidate
4129 ignore-private
4130 ignore-auth
4131 max-stale=NN
4132 refresh-ims
4133 store-stale
4134
4135 override-expire enforces min age even if the server
4136 sent an explicit expiry time (e.g., with the
4137 Expires: header or Cache-Control: max-age). Doing this
4138 VIOLATES the HTTP standard. Enabling this feature
4139 could make you liable for problems which it causes.
4140
4141 Note: override-expire does not enforce staleness - it only extends
4142 freshness / min. If the server returns a Expires time which
4143 is longer than your max time, Squid will still consider
4144 the object fresh for that period of time.
4145
4146 override-lastmod enforces min age even on objects
4147 that were modified recently.
4148
4149 reload-into-ims changes client no-cache or ``reload''
4150 to If-Modified-Since requests. Doing this VIOLATES the
4151 HTTP standard. Enabling this feature could make you
4152 liable for problems which it causes.
4153
4154 ignore-reload ignores a client no-cache or ``reload''
4155 header. Doing this VIOLATES the HTTP standard. Enabling
4156 this feature could make you liable for problems which
4157 it causes.
4158
4159 ignore-no-cache ignores any ``Pragma: no-cache'' and
4160 ``Cache-control: no-cache'' headers received from a server.
4161 The HTTP RFC never allows the use of this (Pragma) header
4162 from a server, only a client, though plenty of servers
4163 send it anyway.
4164
4165 ignore-no-store ignores any ``Cache-control: no-store''
4166 headers received from a server. Doing this VIOLATES
4167 the HTTP standard. Enabling this feature could make you
4168 liable for problems which it causes.
4169
4170 ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
4171 headers received from a server. Doing this VIOLATES
4172 the HTTP standard. Enabling this feature could make you
4173 liable for problems which it causes.
4174
4175 ignore-private ignores any ``Cache-control: private''
4176 headers received from a server. Doing this VIOLATES
4177 the HTTP standard. Enabling this feature could make you
4178 liable for problems which it causes.
4179
4180 ignore-auth caches responses to requests with authorization,
4181 as if the originserver had sent ``Cache-control: public''
4182 in the response header. Doing this VIOLATES the HTTP standard.
4183 Enabling this feature could make you liable for problems which
4184 it causes.
4185
4186 refresh-ims causes squid to contact the origin server
4187 when a client issues an If-Modified-Since request. This
4188 ensures that the client will receive an updated version
4189 if one is available.
4190
4191 store-stale stores responses even if they don't have explicit
4192 freshness or a validator (i.e., Last-Modified or an ETag)
4193 present, or if they're already stale. By default, Squid will
4194 not cache such responses because they usually can't be
4195 reused. Note that such responses will be stale by default.
4196
4197 max-stale=NN provide a maximum staleness factor. Squid won't
4198 serve objects more stale than this even if it failed to
4199 validate the object. Default: use the max_stale global limit.
4200
4201 Basically a cached object is:
4202
4203 FRESH if expires < now, else STALE
4204 STALE if age > max
4205 FRESH if lm-factor < percent, else STALE
4206 FRESH if age < min
4207 else STALE
4208
4209 The refresh_pattern lines are checked in the order listed here.
4210 The first entry which matches is used. If none of the entries
4211 match the default will be used.
4212
4213 Note, you must uncomment all the default lines if you want
4214 to change one. The default setting is only active if none is
4215 used.
4216
4217 NOCOMMENT_START
4218
4219 # Add any of your own refresh_pattern entries above these.
4220 refresh_pattern ^ftp: 1440 20% 10080
4221 refresh_pattern ^gopher: 1440 0% 1440
4222 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
4223 refresh_pattern . 0 20% 4320
4224 NOCOMMENT_END
4225 DOC_END
4226
4227 NAME: quick_abort_min
4228 COMMENT: (KB)
4229 TYPE: kb_int64_t
4230 DEFAULT: 16 KB
4231 LOC: Config.quickAbort.min
4232 DOC_NONE
4233
4234 NAME: quick_abort_max
4235 COMMENT: (KB)
4236 TYPE: kb_int64_t
4237 DEFAULT: 16 KB
4238 LOC: Config.quickAbort.max
4239 DOC_NONE
4240
4241 NAME: quick_abort_pct
4242 COMMENT: (percent)
4243 TYPE: int
4244 DEFAULT: 95
4245 LOC: Config.quickAbort.pct
4246 DOC_START
4247 The cache by default continues downloading aborted requests
4248 which are almost completed (less than 16 KB remaining). This
4249 may be undesirable on slow (e.g. SLIP) links and/or very busy
4250 caches. Impatient users may tie up file descriptors and
4251 bandwidth by repeatedly requesting and immediately aborting
4252 downloads.
4253
4254 When the user aborts a request, Squid will check the
4255 quick_abort values to the amount of data transfered until
4256 then.
4257
4258 If the transfer has less than 'quick_abort_min' KB remaining,
4259 it will finish the retrieval.
4260
4261 If the transfer has more than 'quick_abort_max' KB remaining,
4262 it will abort the retrieval.
4263
4264 If more than 'quick_abort_pct' of the transfer has completed,
4265 it will finish the retrieval.
4266
4267 If you do not want any retrieval to continue after the client
4268 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
4269 to '0 KB'.
4270
4271 If you want retrievals to always continue if they are being
4272 cached set 'quick_abort_min' to '-1 KB'.
4273 DOC_END
4274
4275 NAME: read_ahead_gap
4276 COMMENT: buffer-size
4277 TYPE: b_int64_t
4278 LOC: Config.readAheadGap
4279 DEFAULT: 16 KB
4280 DOC_START
4281 The amount of data the cache will buffer ahead of what has been
4282 sent to the client when retrieving an object from another server.
4283 DOC_END
4284
4285 NAME: negative_ttl
4286 IFDEF: USE_HTTP_VIOLATIONS
4287 COMMENT: time-units
4288 TYPE: time_t
4289 LOC: Config.negativeTtl
4290 DEFAULT: 0 seconds
4291 DOC_START
4292 Set the Default Time-to-Live (TTL) for failed requests.
4293 Certain types of failures (such as "connection refused" and
4294 "404 Not Found") are able to be negatively-cached for a short time.
4295 Modern web servers should provide Expires: header, however if they
4296 do not this can provide a minimum TTL.
4297 The default is not to cache errors with unknown expiry details.
4298
4299 Note that this is different from negative caching of DNS lookups.
4300
4301 WARNING: Doing this VIOLATES the HTTP standard. Enabling
4302 this feature could make you liable for problems which it
4303 causes.
4304 DOC_END
4305
4306 NAME: positive_dns_ttl
4307 COMMENT: time-units
4308 TYPE: time_t
4309 LOC: Config.positiveDnsTtl
4310 DEFAULT: 6 hours
4311 DOC_START
4312 Upper limit on how long Squid will cache positive DNS responses.
4313 Default is 6 hours (360 minutes). This directive must be set
4314 larger than negative_dns_ttl.
4315 DOC_END
4316
4317 NAME: negative_dns_ttl
4318 COMMENT: time-units
4319 TYPE: time_t
4320 LOC: Config.negativeDnsTtl
4321 DEFAULT: 1 minutes
4322 DOC_START
4323 Time-to-Live (TTL) for negative caching of failed DNS lookups.
4324 This also sets the lower cache limit on positive lookups.
4325 Minimum value is 1 second, and it is not recommendable to go
4326 much below 10 seconds.
4327 DOC_END
4328
4329 NAME: range_offset_limit
4330 COMMENT: size [acl acl...]
4331 TYPE: acl_b_size_t
4332 LOC: Config.rangeOffsetLimit
4333 DEFAULT: none
4334 DOC_START
4335 usage: (size) [units] [[!]aclname]
4336
4337 Sets an upper limit on how far (number of bytes) into the file
4338 a Range request may be to cause Squid to prefetch the whole file.
4339 If beyond this limit, Squid forwards the Range request as it is and
4340 the result is NOT cached.
4341
4342 This is to stop a far ahead range request (lets say start at 17MB)
4343 from making Squid fetch the whole object up to that point before
4344 sending anything to the client.
4345
4346 Multiple range_offset_limit lines may be specified, and they will
4347 be searched from top to bottom on each request until a match is found.
4348 The first match found will be used. If no line matches a request, the
4349 default limit of 0 bytes will be used.
4350
4351 'size' is the limit specified as a number of units.
4352
4353 'units' specifies whether to use bytes, KB, MB, etc.
4354 If no units are specified bytes are assumed.
4355
4356 A size of 0 causes Squid to never fetch more than the
4357 client requested. (default)
4358
4359 A size of 'none' causes Squid to always fetch the object from the
4360 beginning so it may cache the result. (2.0 style)
4361
4362 'aclname' is the name of a defined ACL.
4363
4364 NP: Using 'none' as the byte value here will override any quick_abort settings
4365 that may otherwise apply to the range request. The range request will
4366 be fully fetched from start to finish regardless of the client
4367 actions. This affects bandwidth usage.
4368 DOC_END
4369
4370 NAME: minimum_expiry_time
4371 COMMENT: (seconds)
4372 TYPE: time_t
4373 LOC: Config.minimum_expiry_time
4374 DEFAULT: 60 seconds
4375 DOC_START
4376 The minimum caching time according to (Expires - Date)
4377 Headers Squid honors if the object can't be revalidated
4378 defaults to 60 seconds. In reverse proxy environments it
4379 might be desirable to honor shorter object lifetimes. It
4380 is most likely better to make your server return a
4381 meaningful Last-Modified header however. In ESI environments
4382 where page fragments often have short lifetimes, this will
4383 often be best set to 0.
4384 DOC_END
4385
4386 NAME: store_avg_object_size
4387 COMMENT: (bytes)
4388 TYPE: b_int64_t
4389 DEFAULT: 13 KB
4390 LOC: Config.Store.avgObjectSize
4391 DOC_START
4392 Average object size, used to estimate number of objects your
4393 cache can hold. The default is 13 KB.
4394 DOC_END
4395
4396 NAME: store_objects_per_bucket
4397 TYPE: int
4398 DEFAULT: 20
4399 LOC: Config.Store.objectsPerBucket
4400 DOC_START
4401 Target number of objects per bucket in the store hash table.
4402 Lowering this value increases the total number of buckets and
4403 also the storage maintenance rate. The default is 20.
4404 DOC_END
4405
4406 COMMENT_START
4407 HTTP OPTIONS
4408 -----------------------------------------------------------------------------
4409 COMMENT_END
4410
4411 NAME: request_header_max_size
4412 COMMENT: (KB)
4413 TYPE: b_size_t
4414 DEFAULT: 64 KB
4415 LOC: Config.maxRequestHeaderSize
4416 DOC_START
4417 This specifies the maximum size for HTTP headers in a request.
4418 Request headers are usually relatively small (about 512 bytes).
4419 Placing a limit on the request header size will catch certain
4420 bugs (for example with persistent connections) and possibly
4421 buffer-overflow or denial-of-service attacks.
4422 DOC_END
4423
4424 NAME: reply_header_max_size
4425 COMMENT: (KB)
4426 TYPE: b_size_t
4427 DEFAULT: 64 KB
4428 LOC: Config.maxReplyHeaderSize
4429 DOC_START
4430 This specifies the maximum size for HTTP headers in a reply.
4431 Reply headers are usually relatively small (about 512 bytes).
4432 Placing a limit on the reply header size will catch certain
4433 bugs (for example with persistent connections) and possibly
4434 buffer-overflow or denial-of-service attacks.
4435 DOC_END
4436
4437 NAME: request_body_max_size
4438 COMMENT: (bytes)
4439 TYPE: b_int64_t
4440 DEFAULT: 0 KB
4441 LOC: Config.maxRequestBodySize
4442 DOC_START
4443 This specifies the maximum size for an HTTP request body.
4444 In other words, the maximum size of a PUT/POST request.
4445 A user who attempts to send a request with a body larger
4446 than this limit receives an "Invalid Request" error message.
4447 If you set this parameter to a zero (the default), there will
4448 be no limit imposed.
4449 DOC_END
4450
4451 NAME: client_request_buffer_max_size
4452 COMMENT: (bytes)
4453 TYPE: b_size_t
4454 DEFAULT: 512 KB
4455 LOC: Config.maxRequestBufferSize
4456 DOC_START
4457 This specifies the maximum buffer size of a client request.
4458 It prevents squid eating too much memory when somebody uploads
4459 a large file.
4460 DOC_END
4461
4462 NAME: chunked_request_body_max_size
4463 COMMENT: (bytes)
4464 TYPE: b_int64_t
4465 DEFAULT: 64 KB
4466 LOC: Config.maxChunkedRequestBodySize
4467 DOC_START
4468 A broken or confused HTTP/1.1 client may send a chunked HTTP
4469 request to Squid. Squid does not have full support for that
4470 feature yet. To cope with such requests, Squid buffers the
4471 entire request and then dechunks request body to create a
4472 plain HTTP/1.0 request with a known content length. The plain
4473 request is then used by the rest of Squid code as usual.
4474
4475 The option value specifies the maximum size of the buffer used
4476 to hold the request before the conversion. If the chunked
4477 request size exceeds the specified limit, the conversion
4478 fails, and the client receives an "unsupported request" error,
4479 as if dechunking was disabled.
4480
4481 Dechunking is enabled by default. To disable conversion of
4482 chunked requests, set the maximum to zero.
4483
4484 Request dechunking feature and this option in particular are a
4485 temporary hack. When chunking requests and responses are fully
4486 supported, there will be no need to buffer a chunked request.
4487 DOC_END
4488
4489 NAME: broken_posts
4490 IFDEF: USE_HTTP_VIOLATIONS
4491 TYPE: acl_access
4492 DEFAULT: none
4493 LOC: Config.accessList.brokenPosts
4494 DOC_START
4495 A list of ACL elements which, if matched, causes Squid to send
4496 an extra CRLF pair after the body of a PUT/POST request.
4497
4498 Some HTTP servers has broken implementations of PUT/POST,
4499 and rely on an extra CRLF pair sent by some WWW clients.
4500
4501 Quote from RFC2616 section 4.1 on this matter:
4502
4503 Note: certain buggy HTTP/1.0 client implementations generate an
4504 extra CRLF's after a POST request. To restate what is explicitly
4505 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
4506 a request with an extra CRLF.
4507
4508 This clause only supports fast acl types.
4509 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4510
4511 Example:
4512 acl buggy_server url_regex ^http://....
4513 broken_posts allow buggy_server
4514 DOC_END
4515
4516 NAME: adaptation_uses_indirect_client icap_uses_indirect_client
4517 COMMENT: on|off
4518 TYPE: onoff
4519 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
4520 DEFAULT: on
4521 LOC: Adaptation::Config::use_indirect_client
4522 DOC_START
4523 Controls whether the indirect client IP address (instead of the direct
4524 client IP address) is passed to adaptation services.
4525
4526 See also: follow_x_forwarded_for adaptation_send_client_ip
4527 DOC_END
4528
4529 NAME: via
4530 IFDEF: USE_HTTP_VIOLATIONS
4531 COMMENT: on|off
4532 TYPE: onoff
4533 DEFAULT: on
4534 LOC: Config.onoff.via
4535 DOC_START
4536 If set (default), Squid will include a Via header in requests and
4537 replies as required by RFC2616.
4538 DOC_END
4539
4540 NAME: ie_refresh
4541 COMMENT: on|off
4542 TYPE: onoff
4543 LOC: Config.onoff.ie_refresh
4544 DEFAULT: off
4545 DOC_START
4546 Microsoft Internet Explorer up until version 5.5 Service
4547 Pack 1 has an issue with transparent proxies, wherein it
4548 is impossible to force a refresh. Turning this on provides
4549 a partial fix to the problem, by causing all IMS-REFRESH
4550 requests from older IE versions to check the origin server
4551 for fresh content. This reduces hit ratio by some amount
4552 (~10% in my experience), but allows users to actually get
4553 fresh content when they want it. Note because Squid
4554 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
4555 of 5.5 is unchanged from old versions of Squid (i.e. a
4556 forced refresh is impossible). Newer versions of IE will,
4557 hopefully, continue to have the new behavior and will be
4558 handled based on that assumption. This option defaults to
4559 the old Squid behavior, which is better for hit ratios but
4560 worse for clients using IE, if they need to be able to
4561 force fresh content.
4562 DOC_END
4563
4564 NAME: vary_ignore_expire
4565 COMMENT: on|off
4566 TYPE: onoff
4567 LOC: Config.onoff.vary_ignore_expire
4568 DEFAULT: off
4569 DOC_START
4570 Many HTTP servers supporting Vary gives such objects
4571 immediate expiry time with no cache-control header
4572 when requested by a HTTP/1.0 client. This option
4573 enables Squid to ignore such expiry times until
4574 HTTP/1.1 is fully implemented.
4575
4576 WARNING: If turned on this may eventually cause some
4577 varying objects not intended for caching to get cached.
4578 DOC_END
4579
4580 NAME: request_entities
4581 TYPE: onoff
4582 LOC: Config.onoff.request_entities
4583 DEFAULT: off
4584 DOC_START
4585 Squid defaults to deny GET and HEAD requests with request entities,
4586 as the meaning of such requests are undefined in the HTTP standard
4587 even if not explicitly forbidden.
4588
4589 Set this directive to on if you have clients which insists
4590 on sending request entities in GET or HEAD requests. But be warned
4591 that there is server software (both proxies and web servers) which
4592 can fail to properly process this kind of request which may make you
4593 vulnerable to cache pollution attacks if enabled.
4594 DOC_END
4595
4596 NAME: request_header_access
4597 IFDEF: USE_HTTP_VIOLATIONS
4598 TYPE: http_header_access[]
4599 LOC: Config.request_header_access
4600 DEFAULT: none
4601 DOC_START
4602 Usage: request_header_access header_name allow|deny [!]aclname ...
4603
4604 WARNING: Doing this VIOLATES the HTTP standard. Enabling
4605 this feature could make you liable for problems which it
4606 causes.
4607
4608 This option replaces the old 'anonymize_headers' and the
4609 older 'http_anonymizer' option with something that is much
4610 more configurable. This new method creates a list of ACLs
4611 for each header, allowing you very fine-tuned header
4612 mangling.
4613
4614 This option only applies to request headers, i.e., from the
4615 client to the server.
4616
4617 You can only specify known headers for the header name.
4618 Other headers are reclassified as 'Other'. You can also
4619 refer to all the headers with 'All'.
4620
4621 For example, to achieve the same behavior as the old
4622 'http_anonymizer standard' option, you should use:
4623
4624 request_header_access From deny all
4625 request_header_access Referer deny all
4626 request_header_access Server deny all
4627 request_header_access User-Agent deny all
4628 request_header_access WWW-Authenticate deny all
4629 request_header_access Link deny all
4630
4631 Or, to reproduce the old 'http_anonymizer paranoid' feature
4632 you should use:
4633
4634 request_header_access Allow allow all
4635 request_header_access Authorization allow all
4636 request_header_access WWW-Authenticate allow all
4637 request_header_access Proxy-Authorization allow all
4638 request_header_access Proxy-Authenticate allow all
4639 request_header_access Cache-Control allow all
4640 request_header_access Content-Encoding allow all
4641 request_header_access Content-Length allow all
4642 request_header_access Content-Type allow all
4643 request_header_access Date allow all
4644 request_header_access Expires allow all
4645 request_header_access Host allow all
4646 request_header_access If-Modified-Since allow all
4647 request_header_access Last-Modified allow all
4648 request_header_access Location allow all
4649 request_header_access Pragma allow all
4650 request_header_access Accept allow all
4651 request_header_access Accept-Charset allow all
4652 request_header_access Accept-Encoding allow all
4653 request_header_access Accept-Language allow all
4654 request_header_access Content-Language allow all
4655 request_header_access Mime-Version allow all
4656 request_header_access Retry-After allow all
4657 request_header_access Title allow all
4658 request_header_access Connection allow all
4659 request_header_access All deny all
4660
4661 although many of those are HTTP reply headers, and so should be
4662 controlled with the reply_header_access directive.
4663
4664 By default, all headers are allowed (no anonymizing is
4665 performed).
4666 DOC_END
4667
4668 NAME: reply_header_access
4669 IFDEF: USE_HTTP_VIOLATIONS
4670 TYPE: http_header_access[]
4671 LOC: Config.reply_header_access
4672 DEFAULT: none
4673 DOC_START
4674 Usage: reply_header_access header_name allow|deny [!]aclname ...
4675
4676 WARNING: Doing this VIOLATES the HTTP standard. Enabling
4677 this feature could make you liable for problems which it
4678 causes.
4679
4680 This option only applies to reply headers, i.e., from the
4681 server to the client.
4682
4683 This is the same as request_header_access, but in the other
4684 direction.
4685
4686 This option replaces the old 'anonymize_headers' and the
4687 older 'http_anonymizer' option with something that is much
4688 more configurable. This new method creates a list of ACLs
4689 for each header, allowing you very fine-tuned header
4690 mangling.
4691
4692 You can only specify known headers for the header name.
4693 Other headers are reclassified as 'Other'. You can also
4694 refer to all the headers with 'All'.
4695
4696 For example, to achieve the same behavior as the old
4697 'http_anonymizer standard' option, you should use:
4698
4699 reply_header_access From deny all
4700 reply_header_access Referer deny all
4701 reply_header_access Server deny all
4702 reply_header_access User-Agent deny all
4703 reply_header_access WWW-Authenticate deny all
4704 reply_header_access Link deny all
4705
4706 Or, to reproduce the old 'http_anonymizer paranoid' feature
4707 you should use:
4708
4709 reply_header_access Allow allow all
4710 reply_header_access Authorization allow all
4711 reply_header_access WWW-Authenticate allow all
4712 reply_header_access Proxy-Authorization allow all
4713 reply_header_access Proxy-Authenticate allow all
4714 reply_header_access Cache-Control allow all
4715 reply_header_access Content-Encoding allow all
4716 reply_header_access Content-Length allow all
4717 reply_header_access Content-Type allow all
4718 reply_header_access Date allow all
4719 reply_header_access Expires allow all
4720 reply_header_access Host allow all
4721 reply_header_access If-Modified-Since allow all
4722 reply_header_access Last-Modified allow all
4723 reply_header_access Location allow all
4724 reply_header_access Pragma allow all
4725 reply_header_access Accept allow all
4726 reply_header_access Accept-Charset allow all
4727 reply_header_access Accept-Encoding allow all
4728 reply_header_access Accept-Language allow all
4729 reply_header_access Content-Language allow all
4730 reply_header_access Mime-Version allow all
4731 reply_header_access Retry-After allow all
4732 reply_header_access Title allow all
4733 reply_header_access Connection allow all
4734 reply_header_access All deny all
4735
4736 although the HTTP request headers won't be usefully controlled
4737 by this directive -- see request_header_access for details.
4738
4739 By default, all headers are allowed (no anonymizing is
4740 performed).
4741 DOC_END
4742
4743 NAME: request_header_replace header_replace
4744 IFDEF: USE_HTTP_VIOLATIONS
4745 TYPE: http_header_replace[]
4746 LOC: Config.request_header_access
4747 DEFAULT: none
4748 DOC_START
4749 Usage: request_header_replace header_name message
4750 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
4751
4752 This option allows you to change the contents of headers
4753 denied with request_header_access above, by replacing them
4754 with some fixed string. This replaces the old fake_user_agent
4755 option.
4756
4757 This only applies to request headers, not reply headers.
4758
4759 By default, headers are removed if denied.
4760 DOC_END
4761
4762 NAME: reply_header_replace
4763 IFDEF: USE_HTTP_VIOLATIONS
4764 TYPE: http_header_replace[]
4765 LOC: Config.reply_header_access
4766 DEFAULT: none
4767 DOC_START
4768 Usage: reply_header_replace header_name message
4769 Example: reply_header_replace Server Foo/1.0
4770
4771 This option allows you to change the contents of headers
4772 denied with reply_header_access above, by replacing them
4773 with some fixed string.
4774
4775 This only applies to reply headers, not request headers.
4776
4777 By default, headers are removed if denied.
4778 DOC_END
4779
4780 NAME: relaxed_header_parser
4781 COMMENT: on|off|warn
4782 TYPE: tristate
4783 LOC: Config.onoff.relaxed_header_parser
4784 DEFAULT: on
4785 DOC_START
4786 In the default "on" setting Squid accepts certain forms
4787 of non-compliant HTTP messages where it is unambiguous
4788 what the sending application intended even if the message
4789 is not correctly formatted. The messages is then normalized
4790 to the correct form when forwarded by Squid.
4791
4792 If set to "warn" then a warning will be emitted in cache.log
4793 each time such HTTP error is encountered.
4794
4795 If set to "off" then such HTTP errors will cause the request
4796 or response to be rejected.
4797 DOC_END
4798
4799 COMMENT_START
4800 TIMEOUTS
4801 -----------------------------------------------------------------------------
4802 COMMENT_END
4803
4804 NAME: forward_timeout
4805 COMMENT: time-units
4806 TYPE: time_t
4807 LOC: Config.Timeout.forward
4808 DEFAULT: 4 minutes
4809 DOC_START
4810 This parameter specifies how long Squid should at most attempt in
4811 finding a forwarding path for the request before giving up.
4812 DOC_END
4813
4814 NAME: connect_timeout
4815 COMMENT: time-units
4816 TYPE: time_t
4817 LOC: Config.Timeout.connect
4818 DEFAULT: 1 minute
4819 DOC_START
4820 This parameter specifies how long to wait for the TCP connect to
4821 the requested server or peer to complete before Squid should
4822 attempt to find another path where to forward the request.
4823 DOC_END
4824
4825 NAME: peer_connect_timeout
4826 COMMENT: time-units
4827 TYPE: time_t
4828 LOC: Config.Timeout.peer_connect
4829 DEFAULT: 30 seconds
4830 DOC_START
4831 This parameter specifies how long to wait for a pending TCP
4832 connection to a peer cache. The default is 30 seconds. You
4833 may also set different timeout values for individual neighbors
4834 with the 'connect-timeout' option on a 'cache_peer' line.
4835 DOC_END
4836
4837 NAME: read_timeout
4838 COMMENT: time-units
4839 TYPE: time_t
4840 LOC: Config.Timeout.read
4841 DEFAULT: 15 minutes
4842 DOC_START
4843 The read_timeout is applied on server-side connections. After
4844 each successful read(), the timeout will be extended by this
4845 amount. If no data is read again after this amount of time,
4846 the request is aborted and logged with ERR_READ_TIMEOUT. The
4847 default is 15 minutes.
4848 DOC_END
4849
4850 NAME: write_timeout
4851 COMMENT: time-units
4852 TYPE: time_t
4853 LOC: Config.Timeout.write
4854 DEFAULT: 15 minutes
4855 DOC_START
4856 This timeout is tracked for all connections that have data
4857 available for writing and are waiting for the socket to become
4858 ready. After each successful write, the timeout is extended by
4859 the configured amount. If Squid has data to write but the
4860 connection is not ready for the configured duration, the
4861 transaction associated with the connection is terminated. The
4862 default is 15 minutes.
4863 DOC_END
4864
4865 NAME: request_timeout
4866 TYPE: time_t
4867 LOC: Config.Timeout.request
4868 DEFAULT: 5 minutes
4869 DOC_START
4870 How long to wait for complete HTTP request headers after initial
4871 connection establishment.
4872 DOC_END
4873
4874 NAME: client_idle_pconn_timeout persistent_request_timeout
4875 TYPE: time_t
4876 LOC: Config.Timeout.clientIdlePconn
4877 DEFAULT: 2 minutes
4878 DOC_START
4879 How long to wait for the next HTTP request on a persistent
4880 client connection after the previous request completes.
4881 DOC_END
4882
4883 NAME: client_lifetime
4884 COMMENT: time-units
4885 TYPE: time_t
4886 LOC: Config.Timeout.lifetime
4887 DEFAULT: 1 day
4888 DOC_START
4889 The maximum amount of time a client (browser) is allowed to
4890 remain connected to the cache process. This protects the Cache
4891 from having a lot of sockets (and hence file descriptors) tied up
4892 in a CLOSE_WAIT state from remote clients that go away without
4893 properly shutting down (either because of a network failure or
4894 because of a poor client implementation). The default is one
4895 day, 1440 minutes.
4896
4897 NOTE: The default value is intended to be much larger than any
4898 client would ever need to be connected to your cache. You
4899 should probably change client_lifetime only as a last resort.
4900 If you seem to have many client connections tying up
4901 filedescriptors, we recommend first tuning the read_timeout,
4902 request_timeout, persistent_request_timeout and quick_abort values.
4903 DOC_END
4904
4905 NAME: half_closed_clients
4906 TYPE: onoff
4907 LOC: Config.onoff.half_closed_clients
4908 DEFAULT: off
4909 DOC_START
4910 Some clients may shutdown the sending side of their TCP
4911 connections, while leaving their receiving sides open. Sometimes,
4912 Squid can not tell the difference between a half-closed and a
4913 fully-closed TCP connection.
4914
4915 By default, Squid will immediately close client connections when
4916 read(2) returns "no more data to read."
4917
4918 Change this option to 'on' and Squid will keep open connections
4919 until a read(2) or write(2) on the socket returns an error.
4920 This may show some benefits for reverse proxies. But if not
4921 it is recommended to leave OFF.
4922 DOC_END
4923
4924 NAME: server_idle_pconn_timeout pconn_timeout
4925 TYPE: time_t
4926 LOC: Config.Timeout.serverIdlePconn
4927 DEFAULT: 1 minute
4928 DOC_START
4929 Timeout for idle persistent connections to servers and other
4930 proxies.
4931 DOC_END
4932
4933 NAME: ident_timeout
4934 TYPE: time_t
4935 IFDEF: USE_IDENT
4936 LOC: Ident::TheConfig.timeout
4937 DEFAULT: 10 seconds
4938 DOC_START
4939 Maximum time to wait for IDENT lookups to complete.
4940
4941 If this is too high, and you enabled IDENT lookups from untrusted
4942 users, you might be susceptible to denial-of-service by having
4943 many ident requests going at once.
4944 DOC_END
4945
4946 NAME: shutdown_lifetime
4947 COMMENT: time-units
4948 TYPE: time_t
4949 LOC: Config.shutdownLifetime
4950 DEFAULT: 30 seconds
4951 DOC_START
4952 When SIGTERM or SIGHUP is received, the cache is put into
4953 "shutdown pending" mode until all active sockets are closed.
4954 This value is the lifetime to set for all open descriptors
4955 during shutdown mode. Any active clients after this many
4956 seconds will receive a 'timeout' message.
4957 DOC_END
4958
4959 COMMENT_START
4960 ADMINISTRATIVE PARAMETERS
4961 -----------------------------------------------------------------------------
4962 COMMENT_END
4963
4964 NAME: cache_mgr
4965 TYPE: string
4966 DEFAULT: webmaster
4967 LOC: Config.adminEmail
4968 DOC_START
4969 Email-address of local cache manager who will receive
4970 mail if the cache dies. The default is "webmaster."
4971 DOC_END
4972
4973 NAME: mail_from
4974 TYPE: string
4975 DEFAULT: none
4976 LOC: Config.EmailFrom
4977 DOC_START
4978 From: email-address for mail sent when the cache dies.
4979 The default is to use 'appname@unique_hostname'.
4980 Default appname value is "squid", can be changed into
4981 src/globals.h before building squid.
4982 DOC_END
4983
4984 NAME: mail_program
4985 TYPE: eol
4986 DEFAULT: mail
4987 LOC: Config.EmailProgram
4988 DOC_START
4989 Email program used to send mail if the cache dies.
4990 The default is "mail". The specified program must comply
4991 with the standard Unix mail syntax:
4992 mail-program recipient < mailfile
4993
4994 Optional command line options can be specified.
4995 DOC_END
4996
4997 NAME: cache_effective_user
4998 TYPE: string
4999 DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
5000 LOC: Config.effectiveUser
5001 DOC_START
5002 If you start Squid as root, it will change its effective/real
5003 UID/GID to the user specified below. The default is to change
5004 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
5005 see also; cache_effective_group
5006 DOC_END
5007
5008 NAME: cache_effective_group
5009 TYPE: string
5010 DEFAULT: none
5011 LOC: Config.effectiveGroup
5012 DOC_START
5013 Squid sets the GID to the effective user's default group ID
5014 (taken from the password file) and supplementary group list
5015 from the groups membership.
5016
5017 If you want Squid to run with a specific GID regardless of
5018 the group memberships of the effective user then set this
5019 to the group (or GID) you want Squid to run as. When set
5020 all other group privileges of the effective user are ignored
5021 and only this GID is effective. If Squid is not started as
5022 root the user starting Squid MUST be member of the specified
5023 group.
5024
5025 This option is not recommended by the Squid Team.
5026 Our preference is for administrators to configure a secure
5027 user account for squid with UID/GID matching system policies.
5028 DOC_END
5029
5030 NAME: httpd_suppress_version_string
5031 COMMENT: on|off
5032 TYPE: onoff
5033 DEFAULT: off
5034 LOC: Config.onoff.httpd_suppress_version_string
5035 DOC_START
5036 Suppress Squid version string info in HTTP headers and HTML error pages.
5037 DOC_END
5038
5039 NAME: visible_hostname
5040 TYPE: string
5041 LOC: Config.visibleHostname
5042 DEFAULT: none
5043 DOC_START
5044 If you want to present a special hostname in error messages, etc,
5045 define this. Otherwise, the return value of gethostname()
5046 will be used. If you have multiple caches in a cluster and
5047 get errors about IP-forwarding you must set them to have individual
5048 names with this setting.
5049 DOC_END
5050
5051 NAME: unique_hostname
5052 TYPE: string
5053 LOC: Config.uniqueHostname
5054 DEFAULT: none
5055 DOC_START
5056 If you want to have multiple machines with the same
5057 'visible_hostname' you must give each machine a different
5058 'unique_hostname' so forwarding loops can be detected.
5059 DOC_END
5060
5061 NAME: hostname_aliases
5062 TYPE: wordlist
5063 LOC: Config.hostnameAliases
5064 DEFAULT: none
5065 DOC_START
5066 A list of other DNS names your cache has.
5067 DOC_END
5068
5069 NAME: umask
5070 TYPE: int
5071 LOC: Config.umask
5072 DEFAULT: 027
5073 DOC_START
5074 Minimum umask which should be enforced while the proxy
5075 is running, in addition to the umask set at startup.
5076
5077 For a traditional octal representation of umasks, start
5078 your value with 0.
5079 DOC_END
5080
5081 COMMENT_START
5082 OPTIONS FOR THE CACHE REGISTRATION SERVICE
5083 -----------------------------------------------------------------------------
5084
5085 This section contains parameters for the (optional) cache
5086 announcement service. This service is provided to help
5087 cache administrators locate one another in order to join or
5088 create cache hierarchies.
5089
5090 An 'announcement' message is sent (via UDP) to the registration
5091 service by Squid. By default, the announcement message is NOT
5092 SENT unless you enable it with 'announce_period' below.
5093
5094 The announcement message includes your hostname, plus the
5095 following information from this configuration file:
5096
5097 http_port
5098 icp_port
5099 cache_mgr
5100
5101 All current information is processed regularly and made
5102 available on the Web at http://www.ircache.net/Cache/Tracker/.
5103 COMMENT_END
5104
5105 NAME: announce_period
5106 TYPE: time_t
5107 LOC: Config.Announce.period
5108 DEFAULT: 0
5109 DOC_START
5110 This is how frequently to send cache announcements. The
5111 default is `0' which disables sending the announcement
5112 messages.
5113
5114 To enable announcing your cache, just set an announce period.
5115
5116 Example:
5117 announce_period 1 day
5118 DOC_END
5119
5120 NAME: announce_host
5121 TYPE: string
5122 DEFAULT: tracker.ircache.net
5123 LOC: Config.Announce.host
5124 DOC_NONE
5125
5126 NAME: announce_file
5127 TYPE: string
5128 DEFAULT: none
5129 LOC: Config.Announce.file
5130 DOC_NONE
5131
5132 NAME: announce_port
5133 TYPE: u_short
5134 DEFAULT: 3131
5135 LOC: Config.Announce.port
5136 DOC_START
5137 announce_host and announce_port set the hostname and port
5138 number where the registration message will be sent.
5139
5140 Hostname will default to 'tracker.ircache.net' and port will
5141 default default to 3131. If the 'filename' argument is given,
5142 the contents of that file will be included in the announce
5143 message.
5144 DOC_END
5145
5146 COMMENT_START
5147 HTTPD-ACCELERATOR OPTIONS
5148 -----------------------------------------------------------------------------
5149 COMMENT_END
5150
5151 NAME: httpd_accel_surrogate_id
5152 TYPE: string
5153 DEFAULT: none
5154 LOC: Config.Accel.surrogate_id
5155 DOC_START
5156 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
5157 need an identification token to allow control targeting. Because
5158 a farm of surrogates may all perform the same tasks, they may share
5159 an identification token.
5160
5161 The default ID is the visible_hostname
5162 DOC_END
5163
5164 NAME: http_accel_surrogate_remote
5165 COMMENT: on|off
5166 TYPE: onoff
5167 DEFAULT: off
5168 LOC: Config.onoff.surrogate_is_remote
5169 DOC_START
5170 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
5171 Set this to on to have squid behave as a remote surrogate.
5172 DOC_END
5173
5174 NAME: esi_parser
5175 IFDEF: USE_SQUID_ESI
5176 COMMENT: libxml2|expat|custom
5177 TYPE: string
5178 LOC: ESIParser::Type
5179 DEFAULT: custom
5180 DOC_START
5181 ESI markup is not strictly XML compatible. The custom ESI parser
5182 will give higher performance, but cannot handle non ASCII character
5183 encodings.
5184 DOC_END
5185
5186 COMMENT_START
5187 DELAY POOL PARAMETERS
5188 -----------------------------------------------------------------------------
5189 COMMENT_END
5190
5191 NAME: delay_pools
5192 TYPE: delay_pool_count
5193 DEFAULT: 0
5194 IFDEF: USE_DELAY_POOLS
5195 LOC: Config.Delay
5196 DOC_START
5197 This represents the number of delay pools to be used. For example,
5198 if you have one class 2 delay pool and one class 3 delays pool, you
5199 have a total of 2 delay pools.
5200 DOC_END
5201
5202 NAME: delay_class
5203 TYPE: delay_pool_class
5204 DEFAULT: none
5205 IFDEF: USE_DELAY_POOLS
5206 LOC: Config.Delay
5207 DOC_START
5208 This defines the class of each delay pool. There must be exactly one
5209 delay_class line for each delay pool. For example, to define two
5210 delay pools, one of class 2 and one of class 3, the settings above
5211 and here would be:
5212
5213 Example:
5214 delay_pools 4 # 4 delay pools
5215 delay_class 1 2 # pool 1 is a class 2 pool
5216 delay_class 2 3 # pool 2 is a class 3 pool
5217 delay_class 3 4 # pool 3 is a class 4 pool
5218 delay_class 4 5 # pool 4 is a class 5 pool
5219
5220 The delay pool classes are:
5221
5222 class 1 Everything is limited by a single aggregate
5223 bucket.
5224
5225 class 2 Everything is limited by a single aggregate
5226 bucket as well as an "individual" bucket chosen
5227 from bits 25 through 32 of the IPv4 address.
5228
5229 class 3 Everything is limited by a single aggregate
5230 bucket as well as a "network" bucket chosen
5231 from bits 17 through 24 of the IP address and a
5232 "individual" bucket chosen from bits 17 through
5233 32 of the IPv4 address.
5234
5235 class 4 Everything in a class 3 delay pool, with an
5236 additional limit on a per user basis. This
5237 only takes effect if the username is established
5238 in advance - by forcing authentication in your
5239 http_access rules.
5240
5241 class 5 Requests are grouped according their tag (see
5242 external_acl's tag= reply).
5243
5244
5245 Each pool also requires a delay_parameters directive to configure the pool size
5246 and speed limits used whenever the pool is applied to a request. Along with
5247 a set of delay_access directives to determine when it is used.
5248
5249 NOTE: If an IP address is a.b.c.d
5250 -> bits 25 through 32 are "d"
5251 -> bits 17 through 24 are "c"
5252 -> bits 17 through 32 are "c * 256 + d"
5253
5254 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
5255 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
5256 DOC_END
5257
5258 NAME: delay_access
5259 TYPE: delay_pool_access
5260 DEFAULT: none
5261 IFDEF: USE_DELAY_POOLS
5262 LOC: Config.Delay
5263 DOC_START
5264 This is used to determine which delay pool a request falls into.
5265
5266 delay_access is sorted per pool and the matching starts with pool 1,
5267 then pool 2, ..., and finally pool N. The first delay pool where the
5268 request is allowed is selected for the request. If it does not allow
5269 the request to any pool then the request is not delayed (default).
5270
5271 For example, if you want some_big_clients in delay
5272 pool 1 and lotsa_little_clients in delay pool 2:
5273
5274 Example:
5275 delay_access 1 allow some_big_clients
5276 delay_access 1 deny all
5277 delay_access 2 allow lotsa_little_clients
5278 delay_access 2 deny all
5279 delay_access 3 allow authenticated_clients
5280 DOC_END
5281
5282 NAME: delay_parameters
5283 TYPE: delay_pool_rates
5284 DEFAULT: none
5285 IFDEF: USE_DELAY_POOLS
5286 LOC: Config.Delay
5287 DOC_START
5288 This defines the parameters for a delay pool. Each delay pool has
5289 a number of "buckets" associated with it, as explained in the
5290 description of delay_class.
5291
5292 For a class 1 delay pool, the syntax is:
5293 delay_pools pool 1
5294 delay_parameters pool aggregate
5295
5296 For a class 2 delay pool:
5297 delay_pools pool 2
5298 delay_parameters pool aggregate individual
5299
5300 For a class 3 delay pool:
5301 delay_pools pool 3
5302 delay_parameters pool aggregate network individual
5303
5304 For a class 4 delay pool:
5305 delay_pools pool 4
5306 delay_parameters pool aggregate network individual user
5307
5308 For a class 5 delay pool:
5309 delay_pools pool 5
5310 delay_parameters pool tagrate
5311
5312 The option variables are:
5313
5314 pool a pool number - ie, a number between 1 and the
5315 number specified in delay_pools as used in
5316 delay_class lines.
5317
5318 aggregate the speed limit parameters for the aggregate bucket
5319 (class 1, 2, 3).
5320
5321 individual the speed limit parameters for the individual
5322 buckets (class 2, 3).
5323
5324 network the speed limit parameters for the network buckets
5325 (class 3).
5326
5327 user the speed limit parameters for the user buckets
5328 (class 4).
5329
5330 tagrate the speed limit parameters for the tag buckets
5331 (class 5).
5332
5333 A pair of delay parameters is written restore/maximum, where restore is
5334 the number of bytes (not bits - modem and network speeds are usually
5335 quoted in bits) per second placed into the bucket, and maximum is the
5336 maximum number of bytes which can be in the bucket at any time.
5337
5338 There must be one delay_parameters line for each delay pool.
5339
5340
5341 For example, if delay pool number 1 is a class 2 delay pool as in the
5342 above example, and is being used to strictly limit each host to 64Kbit/sec
5343 (plus overheads), with no overall limit, the line is:
5344
5345 delay_parameters 1 -1/-1 8000/8000
5346
5347 Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
5348
5349 Note that the figure -1 is used to represent "unlimited".
5350
5351
5352 And, if delay pool number 2 is a class 3 delay pool as in the above
5353 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
5354 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
5355 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
5356 to permit a decent web page to be downloaded at a decent speed
5357 (if the network is not being limited due to overuse) but slow down
5358 large downloads more significantly:
5359
5360 delay_parameters 2 32000/32000 8000/8000 600/8000
5361
5362 Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
5363 8 x 8000 KByte/sec -> 64Kbit/sec.
5364 8 x 600 Byte/sec -> 4800bit/sec.
5365
5366
5367 Finally, for a class 4 delay pool as in the example - each user will
5368 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
5369
5370 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
5371 DOC_END
5372
5373 NAME: delay_initial_bucket_level
5374 COMMENT: (percent, 0-100)
5375 TYPE: u_short
5376 DEFAULT: 50
5377 IFDEF: USE_DELAY_POOLS
5378 LOC: Config.Delay.initial
5379 DOC_START
5380 The initial bucket percentage is used to determine how much is put
5381 in each bucket when squid starts, is reconfigured, or first notices
5382 a host accessing it (in class 2 and class 3, individual hosts and
5383 networks only have buckets associated with them once they have been
5384 "seen" by squid).
5385 DOC_END
5386
5387 COMMENT_START
5388 CLIENT DELAY POOL PARAMETERS
5389 -----------------------------------------------------------------------------
5390 COMMENT_END
5391
5392 NAME: client_delay_pools
5393 TYPE: client_delay_pool_count
5394 DEFAULT: 0
5395 IFDEF: USE_DELAY_POOLS
5396 LOC: Config.ClientDelay
5397 DOC_START
5398 This option specifies the number of client delay pools used. It must
5399 preceed other client_delay_* options.
5400
5401 Example:
5402 client_delay_pools 2
5403 DOC_END
5404
5405 NAME: client_delay_initial_bucket_level
5406 COMMENT: (percent, 0-no_limit)
5407 TYPE: u_short
5408 DEFAULT: 50
5409 IFDEF: USE_DELAY_POOLS
5410 LOC: Config.ClientDelay.initial
5411 DOC_START
5412 This option determines the initial bucket size as a percentage of
5413 max_bucket_size from client_delay_parameters. Buckets are created
5414 at the time of the "first" connection from the matching IP. Idle
5415 buckets are periodically deleted up.
5416
5417 You can specify more than 100 percent but note that such "oversized"
5418 buckets are not refilled until their size goes down to max_bucket_size
5419 from client_delay_parameters.
5420
5421 Example:
5422 client_delay_initial_bucket_level 50
5423 DOC_END
5424
5425 NAME: client_delay_parameters
5426 TYPE: client_delay_pool_rates
5427 DEFAULT: none
5428 IFDEF: USE_DELAY_POOLS
5429 LOC: Config.ClientDelay
5430 DOC_START
5431
5432 This option configures client-side bandwidth limits using the
5433 following format:
5434
5435 client_delay_parameters pool speed_limit max_bucket_size
5436
5437 pool is an integer ID used for client_delay_access matching.
5438
5439 speed_limit is bytes added to the bucket per second.
5440
5441 max_bucket_size is the maximum size of a bucket, enforced after any
5442 speed_limit additions.
5443
5444 Please see the delay_parameters option for more information and
5445 examples.
5446
5447 Example:
5448 client_delay_parameters 1 1024 2048
5449 client_delay_parameters 2 51200 16384
5450 DOC_END
5451
5452 NAME: client_delay_access
5453 TYPE: client_delay_pool_access
5454 DEFAULT: none
5455 IFDEF: USE_DELAY_POOLS
5456 LOC: Config.ClientDelay
5457 DOC_START
5458
5459 This option determines the client-side delay pool for the
5460 request:
5461
5462 client_delay_access pool_ID allow|deny acl_name
5463
5464 All client_delay_access options are checked in their pool ID
5465 order, starting with pool 1. The first checked pool with allowed
5466 request is selected for the request. If no ACL matches or there
5467 are no client_delay_access options, the request bandwidth is not
5468 limited.
5469
5470 The ACL-selected pool is then used to find the
5471 client_delay_parameters for the request. Client-side pools are
5472 not used to aggregate clients. Clients are always aggregated
5473 based on their source IP addresses (one bucket per source IP).
5474
5475 Please see delay_access for more examples.
5476
5477 Example:
5478 client_delay_access 1 allow low_rate_network
5479 client_delay_access 2 allow vips_network
5480 DOC_END
5481
5482 COMMENT_START
5483 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
5484 -----------------------------------------------------------------------------
5485 COMMENT_END
5486
5487 NAME: wccp_router
5488 TYPE: address
5489 LOC: Config.Wccp.router
5490 DEFAULT: any_addr
5491 IFDEF: USE_WCCP
5492 DOC_START
5493 Use this option to define your WCCP ``home'' router for
5494 Squid.
5495
5496 wccp_router supports a single WCCP(v1) router
5497
5498 wccp2_router supports multiple WCCPv2 routers
5499
5500 only one of the two may be used at the same time and defines
5501 which version of WCCP to use.
5502 DOC_END
5503
5504 NAME: wccp2_router
5505 TYPE: IpAddress_list
5506 LOC: Config.Wccp2.router
5507 DEFAULT: none
5508 IFDEF: USE_WCCPv2
5509 DOC_START
5510 Use this option to define your WCCP ``home'' router for
5511 Squid.
5512
5513 wccp_router supports a single WCCP(v1) router
5514
5515 wccp2_router supports multiple WCCPv2 routers
5516
5517 only one of the two may be used at the same time and defines
5518 which version of WCCP to use.
5519 DOC_END
5520
5521 NAME: wccp_version
5522 TYPE: int
5523 LOC: Config.Wccp.version
5524 DEFAULT: 4
5525 IFDEF: USE_WCCP
5526 DOC_START
5527 This directive is only relevant if you need to set up WCCP(v1)
5528 to some very old and end-of-life Cisco routers. In all other
5529 setups it must be left unset or at the default setting.
5530 It defines an internal version in the WCCP(v1) protocol,
5531 with version 4 being the officially documented protocol.
5532
5533 According to some users, Cisco IOS 11.2 and earlier only
5534 support WCCP version 3. If you're using that or an earlier
5535 version of IOS, you may need to change this value to 3, otherwise
5536 do not specify this parameter.
5537 DOC_END
5538
5539 NAME: wccp2_rebuild_wait
5540 TYPE: onoff
5541 LOC: Config.Wccp2.rebuildwait
5542 DEFAULT: on
5543 IFDEF: USE_WCCPv2
5544 DOC_START
5545 If this is enabled Squid will wait for the cache dir rebuild to finish
5546 before sending the first wccp2 HereIAm packet
5547 DOC_END
5548
5549 NAME: wccp2_forwarding_method
5550 TYPE: wccp2_method
5551 LOC: Config.Wccp2.forwarding_method
5552 DEFAULT: gre
5553 IFDEF: USE_WCCPv2
5554 DOC_START
5555 WCCP2 allows the setting of forwarding methods between the
5556 router/switch and the cache. Valid values are as follows:
5557
5558 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5559 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5560
5561 Currently (as of IOS 12.4) cisco routers only support GRE.
5562 Cisco switches only support the L2 redirect assignment method.
5563 DOC_END
5564
5565 NAME: wccp2_return_method
5566 TYPE: wccp2_method
5567 LOC: Config.Wccp2.return_method
5568 DEFAULT: gre
5569 IFDEF: USE_WCCPv2
5570 DOC_START
5571 WCCP2 allows the setting of return methods between the
5572 router/switch and the cache for packets that the cache
5573 decides not to handle. Valid values are as follows:
5574
5575 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5576 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5577
5578 Currently (as of IOS 12.4) cisco routers only support GRE.
5579 Cisco switches only support the L2 redirect assignment.
5580
5581 If the "ip wccp redirect exclude in" command has been
5582 enabled on the cache interface, then it is still safe for
5583 the proxy server to use a l2 redirect method even if this
5584 option is set to GRE.
5585 DOC_END
5586
5587 NAME: wccp2_assignment_method
5588 TYPE: wccp2_amethod
5589 LOC: Config.Wccp2.assignment_method
5590 DEFAULT: hash
5591 IFDEF: USE_WCCPv2
5592 DOC_START
5593 WCCP2 allows the setting of methods to assign the WCCP hash
5594 Valid values are as follows:
5595
5596 hash - Hash assignment
5597 mask - Mask assignment
5598
5599 As a general rule, cisco routers support the hash assignment method
5600 and cisco switches support the mask assignment method.
5601 DOC_END
5602
5603 NAME: wccp2_service
5604 TYPE: wccp2_service
5605 LOC: Config.Wccp2.info
5606 DEFAULT_IF_NONE: standard 0
5607 IFDEF: USE_WCCPv2
5608 DOC_START
5609 WCCP2 allows for multiple traffic services. There are two
5610 types: "standard" and "dynamic". The standard type defines
5611 one service id - http (id 0). The dynamic service ids can be from
5612 51 to 255 inclusive. In order to use a dynamic service id
5613 one must define the type of traffic to be redirected; this is done
5614 using the wccp2_service_info option.
5615
5616 The "standard" type does not require a wccp2_service_info option,
5617 just specifying the service id will suffice.
5618
5619 MD5 service authentication can be enabled by adding
5620 "password=<password>" to the end of this service declaration.
5621
5622 Examples:
5623
5624 wccp2_service standard 0 # for the 'web-cache' standard service
5625 wccp2_service dynamic 80 # a dynamic service type which will be
5626 # fleshed out with subsequent options.
5627 wccp2_service standard 0 password=foo
5628 DOC_END
5629
5630 NAME: wccp2_service_info
5631 TYPE: wccp2_service_info
5632 LOC: Config.Wccp2.info
5633 DEFAULT: none
5634 IFDEF: USE_WCCPv2
5635 DOC_START
5636 Dynamic WCCPv2 services require further information to define the
5637 traffic you wish to have diverted.
5638
5639 The format is:
5640
5641 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
5642 priority=<priority> ports=<port>,<port>..
5643
5644 The relevant WCCPv2 flags:
5645 + src_ip_hash, dst_ip_hash
5646 + source_port_hash, dst_port_hash
5647 + src_ip_alt_hash, dst_ip_alt_hash
5648 + src_port_alt_hash, dst_port_alt_hash
5649 + ports_source
5650
5651 The port list can be one to eight entries.
5652
5653 Example:
5654
5655 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
5656 priority=240 ports=80
5657
5658 Note: the service id must have been defined by a previous
5659 'wccp2_service dynamic <id>' entry.
5660 DOC_END
5661
5662 NAME: wccp2_weight
5663 TYPE: int
5664 LOC: Config.Wccp2.weight
5665 DEFAULT: 10000
5666 IFDEF: USE_WCCPv2
5667 DOC_START
5668 Each cache server gets assigned a set of the destination
5669 hash proportional to their weight.
5670 DOC_END
5671
5672 NAME: wccp_address
5673 TYPE: address
5674 LOC: Config.Wccp.address
5675 DEFAULT: 0.0.0.0
5676 IFDEF: USE_WCCP
5677 DOC_NONE
5678
5679 NAME: wccp2_address
5680 TYPE: address
5681 LOC: Config.Wccp2.address
5682 DEFAULT: 0.0.0.0
5683 IFDEF: USE_WCCPv2
5684 DOC_START
5685 Use this option if you require WCCP to use a specific
5686 interface address.
5687
5688 The default behavior is to not bind to any specific address.
5689 DOC_END
5690
5691 COMMENT_START
5692 PERSISTENT CONNECTION HANDLING
5693 -----------------------------------------------------------------------------
5694
5695 Also see "pconn_timeout" in the TIMEOUTS section
5696 COMMENT_END
5697
5698 NAME: client_persistent_connections
5699 TYPE: onoff
5700 LOC: Config.onoff.client_pconns
5701 DEFAULT: on
5702 DOC_NONE
5703
5704 NAME: server_persistent_connections
5705 TYPE: onoff
5706 LOC: Config.onoff.server_pconns
5707 DEFAULT: on
5708 DOC_START
5709 Persistent connection support for clients and servers. By
5710 default, Squid uses persistent connections (when allowed)
5711 with its clients and servers. You can use these options to
5712 disable persistent connections with clients and/or servers.
5713 DOC_END
5714
5715 NAME: persistent_connection_after_error
5716 TYPE: onoff
5717 LOC: Config.onoff.error_pconns
5718 DEFAULT: on
5719 DOC_START
5720 With this directive the use of persistent connections after
5721 HTTP errors can be disabled. Useful if you have clients
5722 who fail to handle errors on persistent connections proper.
5723 DOC_END
5724
5725 NAME: detect_broken_pconn
5726 TYPE: onoff
5727 LOC: Config.onoff.detect_broken_server_pconns
5728 DEFAULT: off
5729 DOC_START
5730 Some servers have been found to incorrectly signal the use
5731 of HTTP/1.0 persistent connections even on replies not
5732 compatible, causing significant delays. This server problem
5733 has mostly been seen on redirects.
5734
5735 By enabling this directive Squid attempts to detect such
5736 broken replies and automatically assume the reply is finished
5737 after 10 seconds timeout.
5738 DOC_END
5739
5740 COMMENT_START
5741 CACHE DIGEST OPTIONS
5742 -----------------------------------------------------------------------------
5743 COMMENT_END
5744
5745 NAME: digest_generation
5746 IFDEF: USE_CACHE_DIGESTS
5747 TYPE: onoff
5748 LOC: Config.onoff.digest_generation
5749 DEFAULT: on
5750 DOC_START
5751 This controls whether the server will generate a Cache Digest
5752 of its contents. By default, Cache Digest generation is
5753 enabled if Squid is compiled with --enable-cache-digests defined.
5754 DOC_END
5755
5756 NAME: digest_bits_per_entry
5757 IFDEF: USE_CACHE_DIGESTS
5758 TYPE: int
5759 LOC: Config.digest.bits_per_entry
5760 DEFAULT: 5
5761 DOC_START
5762 This is the number of bits of the server's Cache Digest which
5763 will be associated with the Digest entry for a given HTTP
5764 Method and URL (public key) combination. The default is 5.
5765 DOC_END
5766
5767 NAME: digest_rebuild_period
5768 IFDEF: USE_CACHE_DIGESTS
5769 COMMENT: (seconds)
5770 TYPE: time_t
5771 LOC: Config.digest.rebuild_period
5772 DEFAULT: 1 hour
5773 DOC_START
5774 This is the wait time between Cache Digest rebuilds.
5775 DOC_END
5776
5777 NAME: digest_rewrite_period
5778 COMMENT: (seconds)
5779 IFDEF: USE_CACHE_DIGESTS
5780 TYPE: time_t
5781 LOC: Config.digest.rewrite_period
5782 DEFAULT: 1 hour
5783 DOC_START
5784 This is the wait time between Cache Digest writes to
5785 disk.
5786 DOC_END
5787
5788 NAME: digest_swapout_chunk_size
5789 COMMENT: (bytes)
5790 TYPE: b_size_t
5791 IFDEF: USE_CACHE_DIGESTS
5792 LOC: Config.digest.swapout_chunk_size
5793 DEFAULT: 4096 bytes
5794 DOC_START
5795 This is the number of bytes of the Cache Digest to write to
5796 disk at a time. It defaults to 4096 bytes (4KB), the Squid
5797 default swap page.
5798 DOC_END
5799
5800 NAME: digest_rebuild_chunk_percentage
5801 COMMENT: (percent, 0-100)
5802 IFDEF: USE_CACHE_DIGESTS
5803 TYPE: int
5804 LOC: Config.digest.rebuild_chunk_percentage
5805 DEFAULT: 10
5806 DOC_START
5807 This is the percentage of the Cache Digest to be scanned at a
5808 time. By default it is set to 10% of the Cache Digest.
5809 DOC_END
5810
5811 COMMENT_START
5812 SNMP OPTIONS
5813 -----------------------------------------------------------------------------
5814 COMMENT_END
5815
5816 NAME: snmp_port
5817 TYPE: u_short
5818 LOC: Config.Port.snmp
5819 DEFAULT: 0
5820 IFDEF: SQUID_SNMP
5821 DOC_START
5822 The port number where Squid listens for SNMP requests. To enable
5823 SNMP support set this to a suitable port number. Port number
5824 3401 is often used for the Squid SNMP agent. By default it's
5825 set to "0" (disabled)
5826
5827 Example:
5828 snmp_port 3401
5829 DOC_END
5830
5831 NAME: snmp_access
5832 TYPE: acl_access
5833 LOC: Config.accessList.snmp
5834 DEFAULT_IF_NONE: deny all
5835 IFDEF: SQUID_SNMP
5836 DOC_START
5837 Allowing or denying access to the SNMP port.
5838
5839 All access to the agent is denied by default.
5840 usage:
5841
5842 snmp_access allow|deny [!]aclname ...
5843
5844 This clause only supports fast acl types.
5845 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5846 Example:
5847 snmp_access allow snmppublic localhost
5848 snmp_access deny all
5849 DOC_END
5850
5851 NAME: snmp_incoming_address
5852 TYPE: address
5853 LOC: Config.Addrs.snmp_incoming
5854 DEFAULT: any_addr
5855 IFDEF: SQUID_SNMP
5856 DOC_NONE
5857
5858 NAME: snmp_outgoing_address
5859 TYPE: address
5860 LOC: Config.Addrs.snmp_outgoing
5861 DEFAULT: no_addr
5862 IFDEF: SQUID_SNMP
5863 DOC_START
5864 Just like 'udp_incoming_address', but for the SNMP port.
5865
5866 snmp_incoming_address is used for the SNMP socket receiving
5867 messages from SNMP agents.
5868 snmp_outgoing_address is used for SNMP packets returned to SNMP
5869 agents.
5870
5871 The default snmp_incoming_address is to listen on all
5872 available network interfaces.
5873
5874 If snmp_outgoing_address is not set it will use the same socket
5875 as snmp_incoming_address. Only change this if you want to have
5876 SNMP replies sent using another address than where this Squid
5877 listens for SNMP queries.
5878
5879 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
5880 the same value since they both use port 3401.
5881 DOC_END
5882
5883 COMMENT_START
5884 ICP OPTIONS
5885 -----------------------------------------------------------------------------
5886 COMMENT_END
5887
5888 NAME: icp_port udp_port
5889 TYPE: u_short
5890 DEFAULT: 0
5891 LOC: Config.Port.icp
5892 DOC_START
5893 The port number where Squid sends and receives ICP queries to
5894 and from neighbor caches. The standard UDP port for ICP is 3130.
5895 Default is disabled (0).
5896
5897 Example:
5898 icp_port @DEFAULT_ICP_PORT@
5899 DOC_END
5900
5901 NAME: htcp_port
5902 IFDEF: USE_HTCP
5903 TYPE: u_short
5904 DEFAULT: 0
5905 LOC: Config.Port.htcp
5906 DOC_START
5907 The port number where Squid sends and receives HTCP queries to
5908 and from neighbor caches. To turn it on you want to set it to
5909 4827. By default it is set to "0" (disabled).
5910
5911 Example:
5912 htcp_port 4827
5913 DOC_END
5914
5915 NAME: log_icp_queries
5916 COMMENT: on|off
5917 TYPE: onoff
5918 DEFAULT: on
5919 LOC: Config.onoff.log_udp
5920 DOC_START
5921 If set, ICP queries are logged to access.log. You may wish
5922 do disable this if your ICP load is VERY high to speed things
5923 up or to simplify log analysis.
5924 DOC_END
5925
5926 NAME: udp_incoming_address
5927 TYPE: address
5928 LOC:Config.Addrs.udp_incoming
5929 DEFAULT: any_addr
5930 DOC_START
5931 udp_incoming_address is used for UDP packets received from other
5932 caches.
5933
5934 The default behavior is to not bind to any specific address.
5935
5936 Only change this if you want to have all UDP queries received on
5937 a specific interface/address.
5938
5939 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
5940 modules. Altering it will affect all of them in the same manner.
5941
5942 see also; udp_outgoing_address
5943
5944 NOTE, udp_incoming_address and udp_outgoing_address can not
5945 have the same value since they both use the same port.
5946 DOC_END
5947
5948 NAME: udp_outgoing_address
5949 TYPE: address
5950 LOC: Config.Addrs.udp_outgoing
5951 DEFAULT: no_addr
5952 DOC_START
5953 udp_outgoing_address is used for UDP packets sent out to other
5954 caches.
5955
5956 The default behavior is to not bind to any specific address.
5957
5958 Instead it will use the same socket as udp_incoming_address.
5959 Only change this if you want to have UDP queries sent using another
5960 address than where this Squid listens for UDP queries from other
5961 caches.
5962
5963 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
5964 modules. Altering it will affect all of them in the same manner.
5965
5966 see also; udp_incoming_address
5967
5968 NOTE, udp_incoming_address and udp_outgoing_address can not
5969 have the same value since they both use the same port.
5970 DOC_END
5971
5972 NAME: icp_hit_stale
5973 COMMENT: on|off
5974 TYPE: onoff
5975 DEFAULT: off
5976 LOC: Config.onoff.icp_hit_stale
5977 DOC_START
5978 If you want to return ICP_HIT for stale cache objects, set this
5979 option to 'on'. If you have sibling relationships with caches
5980 in other administrative domains, this should be 'off'. If you only
5981 have sibling relationships with caches under your control,
5982 it is probably okay to set this to 'on'.
5983 If set to 'on', your siblings should use the option "allow-miss"
5984 on their cache_peer lines for connecting to you.
5985 DOC_END
5986
5987 NAME: minimum_direct_hops
5988 TYPE: int
5989 DEFAULT: 4
5990 LOC: Config.minDirectHops
5991 DOC_START
5992 If using the ICMP pinging stuff, do direct fetches for sites
5993 which are no more than this many hops away.
5994 DOC_END
5995
5996 NAME: minimum_direct_rtt
5997 TYPE: int
5998 DEFAULT: 400
5999 LOC: Config.minDirectRtt
6000 DOC_START
6001 If using the ICMP pinging stuff, do direct fetches for sites
6002 which are no more than this many rtt milliseconds away.
6003 DOC_END
6004
6005 NAME: netdb_low
6006 TYPE: int
6007 DEFAULT: 900
6008 LOC: Config.Netdb.low
6009 DOC_NONE
6010
6011 NAME: netdb_high
6012 TYPE: int
6013 DEFAULT: 1000
6014 LOC: Config.Netdb.high
6015 DOC_START
6016 The low and high water marks for the ICMP measurement
6017 database. These are counts, not percents. The defaults are
6018 900 and 1000. When the high water mark is reached, database
6019 entries will be deleted until the low mark is reached.
6020 DOC_END
6021
6022 NAME: netdb_ping_period
6023 TYPE: time_t
6024 LOC: Config.Netdb.period
6025 DEFAULT: 5 minutes
6026 DOC_START
6027 The minimum period for measuring a site. There will be at
6028 least this much delay between successive pings to the same
6029 network. The default is five minutes.
6030 DOC_END
6031
6032 NAME: query_icmp
6033 COMMENT: on|off
6034 TYPE: onoff
6035 DEFAULT: off
6036 LOC: Config.onoff.query_icmp
6037 DOC_START
6038 If you want to ask your peers to include ICMP data in their ICP
6039 replies, enable this option.
6040
6041 If your peer has configured Squid (during compilation) with
6042 '--enable-icmp' that peer will send ICMP pings to origin server
6043 sites of the URLs it receives. If you enable this option the
6044 ICP replies from that peer will include the ICMP data (if available).
6045 Then, when choosing a parent cache, Squid will choose the parent with
6046 the minimal RTT to the origin server. When this happens, the
6047 hierarchy field of the access.log will be
6048 "CLOSEST_PARENT_MISS". This option is off by default.
6049 DOC_END
6050
6051 NAME: test_reachability
6052 COMMENT: on|off
6053 TYPE: onoff
6054 DEFAULT: off
6055 LOC: Config.onoff.test_reachability
6056 DOC_START
6057 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
6058 instead of ICP_MISS if the target host is NOT in the ICMP
6059 database, or has a zero RTT.
6060 DOC_END
6061
6062 NAME: icp_query_timeout
6063 COMMENT: (msec)
6064 DEFAULT: 0
6065 TYPE: int
6066 LOC: Config.Timeout.icp_query
6067 DOC_START
6068 Normally Squid will automatically determine an optimal ICP
6069 query timeout value based on the round-trip-time of recent ICP
6070 queries. If you want to override the value determined by
6071 Squid, set this 'icp_query_timeout' to a non-zero value. This
6072 value is specified in MILLISECONDS, so, to use a 2-second
6073 timeout (the old default), you would write:
6074
6075 icp_query_timeout 2000
6076 DOC_END
6077
6078 NAME: maximum_icp_query_timeout
6079 COMMENT: (msec)
6080 DEFAULT: 2000
6081 TYPE: int
6082 LOC: Config.Timeout.icp_query_max
6083 DOC_START
6084 Normally the ICP query timeout is determined dynamically. But
6085 sometimes it can lead to very large values (say 5 seconds).
6086 Use this option to put an upper limit on the dynamic timeout
6087 value. Do NOT use this option to always use a fixed (instead
6088 of a dynamic) timeout value. To set a fixed timeout see the
6089 'icp_query_timeout' directive.
6090 DOC_END
6091
6092 NAME: minimum_icp_query_timeout
6093 COMMENT: (msec)
6094 DEFAULT: 5
6095 TYPE: int
6096 LOC: Config.Timeout.icp_query_min
6097 DOC_START
6098 Normally the ICP query timeout is determined dynamically. But
6099 sometimes it can lead to very small timeouts, even lower than
6100 the normal latency variance on your link due to traffic.
6101 Use this option to put an lower limit on the dynamic timeout
6102 value. Do NOT use this option to always use a fixed (instead
6103 of a dynamic) timeout value. To set a fixed timeout see the
6104 'icp_query_timeout' directive.
6105 DOC_END
6106
6107 NAME: background_ping_rate
6108 COMMENT: time-units
6109 TYPE: time_t
6110 DEFAULT: 10 seconds
6111 LOC: Config.backgroundPingRate
6112 DOC_START
6113 Controls how often the ICP pings are sent to siblings that
6114 have background-ping set.
6115 DOC_END
6116
6117 COMMENT_START
6118 MULTICAST ICP OPTIONS
6119 -----------------------------------------------------------------------------
6120 COMMENT_END
6121
6122 NAME: mcast_groups
6123 TYPE: wordlist
6124 LOC: Config.mcast_group_list
6125 DEFAULT: none
6126 DOC_START
6127 This tag specifies a list of multicast groups which your server
6128 should join to receive multicasted ICP queries.
6129
6130 NOTE! Be very careful what you put here! Be sure you
6131 understand the difference between an ICP _query_ and an ICP
6132 _reply_. This option is to be set only if you want to RECEIVE
6133 multicast queries. Do NOT set this option to SEND multicast
6134 ICP (use cache_peer for that). ICP replies are always sent via
6135 unicast, so this option does not affect whether or not you will
6136 receive replies from multicast group members.
6137
6138 You must be very careful to NOT use a multicast address which
6139 is already in use by another group of caches.
6140
6141 If you are unsure about multicast, please read the Multicast
6142 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
6143
6144 Usage: mcast_groups 239.128.16.128 224.0.1.20
6145
6146 By default, Squid doesn't listen on any multicast groups.
6147 DOC_END
6148
6149 NAME: mcast_miss_addr
6150 IFDEF: MULTICAST_MISS_STREAM
6151 TYPE: address
6152 LOC: Config.mcast_miss.addr
6153 DEFAULT: no_addr
6154 DOC_START
6155 If you enable this option, every "cache miss" URL will
6156 be sent out on the specified multicast address.
6157
6158 Do not enable this option unless you are are absolutely
6159 certain you understand what you are doing.
6160 DOC_END
6161
6162 NAME: mcast_miss_ttl
6163 IFDEF: MULTICAST_MISS_STREAM
6164 TYPE: u_short
6165 LOC: Config.mcast_miss.ttl
6166 DEFAULT: 16
6167 DOC_START
6168 This is the time-to-live value for packets multicasted
6169 when multicasting off cache miss URLs is enabled. By
6170 default this is set to 'site scope', i.e. 16.
6171 DOC_END
6172
6173 NAME: mcast_miss_port
6174 IFDEF: MULTICAST_MISS_STREAM
6175 TYPE: u_short
6176 LOC: Config.mcast_miss.port
6177 DEFAULT: 3135
6178 DOC_START
6179 This is the port number to be used in conjunction with
6180 'mcast_miss_addr'.
6181 DOC_END
6182
6183 NAME: mcast_miss_encode_key
6184 IFDEF: MULTICAST_MISS_STREAM
6185 TYPE: string
6186 LOC: Config.mcast_miss.encode_key
6187 DEFAULT: XXXXXXXXXXXXXXXX
6188 DOC_START
6189 The URLs that are sent in the multicast miss stream are
6190 encrypted. This is the encryption key.
6191 DOC_END
6192
6193 NAME: mcast_icp_query_timeout
6194 COMMENT: (msec)
6195 DEFAULT: 2000
6196 TYPE: int
6197 LOC: Config.Timeout.mcast_icp_query
6198 DOC_START
6199 For multicast peers, Squid regularly sends out ICP "probes" to
6200 count how many other peers are listening on the given multicast
6201 address. This value specifies how long Squid should wait to
6202 count all the replies. The default is 2000 msec, or 2
6203 seconds.
6204 DOC_END
6205
6206 COMMENT_START
6207 INTERNAL ICON OPTIONS
6208 -----------------------------------------------------------------------------
6209 COMMENT_END
6210
6211 NAME: icon_directory
6212 TYPE: string
6213 LOC: Config.icons.directory
6214 DEFAULT: @DEFAULT_ICON_DIR@
6215 DOC_START
6216 Where the icons are stored. These are normally kept in
6217 @DEFAULT_ICON_DIR@
6218 DOC_END
6219
6220 NAME: global_internal_static
6221 TYPE: onoff
6222 LOC: Config.onoff.global_internal_static
6223 DEFAULT: on
6224 DOC_START
6225 This directive controls is Squid should intercept all requests for
6226 /squid-internal-static/ no matter which host the URL is requesting
6227 (default on setting), or if nothing special should be done for
6228 such URLs (off setting). The purpose of this directive is to make
6229 icons etc work better in complex cache hierarchies where it may
6230 not always be possible for all corners in the cache mesh to reach
6231 the server generating a directory listing.
6232 DOC_END
6233
6234 NAME: short_icon_urls
6235 TYPE: onoff
6236 LOC: Config.icons.use_short_names
6237 DEFAULT: on
6238 DOC_START
6239 If this is enabled Squid will use short URLs for icons.
6240 If disabled it will revert to the old behavior of including
6241 it's own name and port in the URL.
6242
6243 If you run a complex cache hierarchy with a mix of Squid and
6244 other proxies you may need to disable this directive.
6245 DOC_END
6246
6247 COMMENT_START
6248 ERROR PAGE OPTIONS
6249 -----------------------------------------------------------------------------
6250 COMMENT_END
6251
6252 NAME: error_directory
6253 TYPE: string
6254 LOC: Config.errorDirectory
6255 DEFAULT: none
6256 DOC_START
6257 If you wish to create your own versions of the default
6258 error files to customize them to suit your company copy
6259 the error/template files to another directory and point
6260 this tag at them.
6261
6262 WARNING: This option will disable multi-language support
6263 on error pages if used.
6264
6265 The squid developers are interested in making squid available in
6266 a wide variety of languages. If you are making translations for a
6267 language that Squid does not currently provide please consider
6268 contributing your translation back to the project.
6269 http://wiki.squid-cache.org/Translations
6270
6271 The squid developers working on translations are happy to supply drop-in
6272 translated error files in exchange for any new language contributions.
6273 DOC_END
6274
6275 NAME: error_default_language
6276 IFDEF: USE_ERR_LOCALES
6277 TYPE: string
6278 LOC: Config.errorDefaultLanguage
6279 DEFAULT: none
6280 DOC_START
6281 Set the default language which squid will send error pages in
6282 if no existing translation matches the clients language
6283 preferences.
6284
6285 If unset (default) generic English will be used.
6286
6287 The squid developers are interested in making squid available in
6288 a wide variety of languages. If you are interested in making
6289 translations for any language see the squid wiki for details.
6290 http://wiki.squid-cache.org/Translations
6291 DOC_END
6292
6293 NAME: error_log_languages
6294 IFDEF: USE_ERR_LOCALES
6295 TYPE: onoff
6296 LOC: Config.errorLogMissingLanguages
6297 DEFAULT: on
6298 DOC_START
6299 Log to cache.log what languages users are attempting to
6300 auto-negotiate for translations.
6301
6302 Successful negotiations are not logged. Only failures
6303 have meaning to indicate that Squid may need an upgrade
6304 of its error page translations.
6305 DOC_END
6306
6307 NAME: err_page_stylesheet
6308 TYPE: string
6309 LOC: Config.errorStylesheet
6310 DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
6311 DOC_START
6312 CSS Stylesheet to pattern the display of Squid default error pages.
6313
6314 For information on CSS see http://www.w3.org/Style/CSS/
6315 DOC_END
6316
6317 NAME: err_html_text
6318 TYPE: eol
6319 LOC: Config.errHtmlText
6320 DEFAULT: none
6321 DOC_START
6322 HTML text to include in error messages. Make this a "mailto"
6323 URL to your admin address, or maybe just a link to your
6324 organizations Web page.
6325
6326 To include this in your error messages, you must rewrite
6327 the error template files (found in the "errors" directory).
6328 Wherever you want the 'err_html_text' line to appear,
6329 insert a %L tag in the error template file.
6330 DOC_END
6331
6332 NAME: email_err_data
6333 COMMENT: on|off
6334 TYPE: onoff
6335 LOC: Config.onoff.emailErrData
6336 DEFAULT: on
6337 DOC_START
6338 If enabled, information about the occurred error will be
6339 included in the mailto links of the ERR pages (if %W is set)
6340 so that the email body contains the data.
6341 Syntax is <A HREF="mailto:%w%W">%w</A>
6342 DOC_END
6343
6344 NAME: deny_info
6345 TYPE: denyinfo
6346 LOC: Config.denyInfoList
6347 DEFAULT: none
6348 DOC_START
6349 Usage: deny_info err_page_name acl
6350 or deny_info http://... acl
6351 or deny_info TCP_RESET acl
6352
6353 This can be used to return a ERR_ page for requests which
6354 do not pass the 'http_access' rules. Squid remembers the last
6355 acl it evaluated in http_access, and if a 'deny_info' line exists
6356 for that ACL Squid returns a corresponding error page.
6357
6358 The acl is typically the last acl on the http_access deny line which
6359 denied access. The exceptions to this rule are:
6360 - When Squid needs to request authentication credentials. It's then
6361 the first authentication related acl encountered
6362 - When none of the http_access lines matches. It's then the last
6363 acl processed on the last http_access line.
6364 - When the decision to deny access was made by an adaptation service,
6365 the acl name is the corresponding eCAP or ICAP service_name.
6366
6367 NP: If providing your own custom error pages with error_directory
6368 you may also specify them by your custom file name:
6369 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
6370
6371 By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
6372 may be specified by prefixing the file name with the code and a colon.
6373 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
6374
6375 Alternatively you can tell Squid to reset the TCP connection
6376 by specifying TCP_RESET.
6377
6378 Or you can specify an error URL or URL pattern. The browsers will
6379 get redirected to the specified URL after formatting tags have
6380 been replaced. Redirect will be done with 302 or 307 according to
6381 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
6382 the URL. e.g. 303:http://example.com/
6383
6384 URL FORMAT TAGS:
6385 %a - username (if available. Password NOT included)
6386 %B - FTP path URL
6387 %e - Error number
6388 %E - Error description
6389 %h - Squid hostname
6390 %H - Request domain name
6391 %i - Client IP Address
6392 %M - Request Method
6393 %o - Message result from external ACL helper
6394 %p - Request Port number
6395 %P - Request Protocol name
6396 %R - Request URL path
6397 %T - Timestamp in RFC 1123 format
6398 %U - Full canonical URL from client
6399 (HTTPS URLs terminate with *)
6400 %u - Full canonical URL from client
6401 %w - Admin email from squid.conf
6402 %x - Error name
6403 %% - Literal percent (%) code
6404
6405 DOC_END
6406
6407 COMMENT_START
6408 OPTIONS INFLUENCING REQUEST FORWARDING
6409 -----------------------------------------------------------------------------
6410 COMMENT_END
6411
6412 NAME: nonhierarchical_direct
6413 TYPE: onoff
6414 LOC: Config.onoff.nonhierarchical_direct
6415 DEFAULT: on
6416 DOC_START
6417 By default, Squid will send any non-hierarchical requests
6418 (matching hierarchy_stoplist or not cacheable request type) direct
6419 to origin servers.
6420
6421 If you set this to off, Squid will prefer to send these
6422 requests to parents.
6423
6424 Note that in most configurations, by turning this off you will only
6425 add latency to these request without any improvement in global hit
6426 ratio.
6427
6428 If you are inside an firewall see never_direct instead of
6429 this directive.
6430 DOC_END
6431
6432 NAME: prefer_direct
6433 TYPE: onoff
6434 LOC: Config.onoff.prefer_direct
6435 DEFAULT: off
6436 DOC_START
6437 Normally Squid tries to use parents for most requests. If you for some
6438 reason like it to first try going direct and only use a parent if
6439 going direct fails set this to on.
6440
6441 By combining nonhierarchical_direct off and prefer_direct on you
6442 can set up Squid to use a parent as a backup path if going direct
6443 fails.
6444
6445 Note: If you want Squid to use parents for all requests see
6446 the never_direct directive. prefer_direct only modifies how Squid
6447 acts on cacheable requests.
6448 DOC_END
6449
6450 NAME: always_direct
6451 TYPE: acl_access
6452 LOC: Config.accessList.AlwaysDirect
6453 DEFAULT: none
6454 DOC_START
6455 Usage: always_direct allow|deny [!]aclname ...
6456
6457 Here you can use ACL elements to specify requests which should
6458 ALWAYS be forwarded by Squid to the origin servers without using
6459 any peers. For example, to always directly forward requests for
6460 local servers ignoring any parents or siblings you may have use
6461 something like:
6462
6463 acl local-servers dstdomain my.domain.net
6464 always_direct allow local-servers
6465
6466 To always forward FTP requests directly, use
6467
6468 acl FTP proto FTP
6469 always_direct allow FTP
6470
6471 NOTE: There is a similar, but opposite option named
6472 'never_direct'. You need to be aware that "always_direct deny
6473 foo" is NOT the same thing as "never_direct allow foo". You
6474 may need to use a deny rule to exclude a more-specific case of
6475 some other rule. Example:
6476
6477 acl local-external dstdomain external.foo.net
6478 acl local-servers dstdomain .foo.net
6479 always_direct deny local-external
6480 always_direct allow local-servers
6481
6482 NOTE: If your goal is to make the client forward the request
6483 directly to the origin server bypassing Squid then this needs
6484 to be done in the client configuration. Squid configuration
6485 can only tell Squid how Squid should fetch the object.
6486
6487 NOTE: This directive is not related to caching. The replies
6488 is cached as usual even if you use always_direct. To not cache
6489 the replies see the 'cache' directive.
6490
6491 This clause supports both fast and slow acl types.
6492 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6493 DOC_END
6494
6495 NAME: never_direct
6496 TYPE: acl_access
6497 LOC: Config.accessList.NeverDirect
6498 DEFAULT: none
6499 DOC_START
6500 Usage: never_direct allow|deny [!]aclname ...
6501
6502 never_direct is the opposite of always_direct. Please read
6503 the description for always_direct if you have not already.
6504
6505 With 'never_direct' you can use ACL elements to specify
6506 requests which should NEVER be forwarded directly to origin
6507 servers. For example, to force the use of a proxy for all
6508 requests, except those in your local domain use something like:
6509
6510 acl local-servers dstdomain .foo.net
6511 never_direct deny local-servers
6512 never_direct allow all
6513
6514 or if Squid is inside a firewall and there are local intranet
6515 servers inside the firewall use something like:
6516
6517 acl local-intranet dstdomain .foo.net
6518 acl local-external dstdomain external.foo.net
6519 always_direct deny local-external
6520 always_direct allow local-intranet
6521 never_direct allow all
6522
6523 This clause supports both fast and slow acl types.
6524 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6525 DOC_END
6526
6527 COMMENT_START
6528 ADVANCED NETWORKING OPTIONS
6529 -----------------------------------------------------------------------------
6530 COMMENT_END
6531
6532 NAME: incoming_icp_average
6533 TYPE: int
6534 DEFAULT: 6
6535 LOC: Config.comm_incoming.icp_average
6536 DOC_NONE
6537
6538 NAME: incoming_http_average
6539 TYPE: int
6540 DEFAULT: 4
6541 LOC: Config.comm_incoming.http_average
6542 DOC_NONE
6543
6544 NAME: incoming_dns_average
6545 TYPE: int
6546 DEFAULT: 4
6547 LOC: Config.comm_incoming.dns_average
6548 DOC_NONE
6549
6550 NAME: min_icp_poll_cnt
6551 TYPE: int
6552 DEFAULT: 8
6553 LOC: Config.comm_incoming.icp_min_poll
6554 DOC_NONE
6555
6556 NAME: min_dns_poll_cnt
6557 TYPE: int
6558 DEFAULT: 8
6559 LOC: Config.comm_incoming.dns_min_poll
6560 DOC_NONE
6561
6562 NAME: min_http_poll_cnt
6563 TYPE: int
6564 DEFAULT: 8
6565 LOC: Config.comm_incoming.http_min_poll
6566 DOC_START
6567 Heavy voodoo here. I can't even believe you are reading this.
6568 Are you crazy? Don't even think about adjusting these unless
6569 you understand the algorithms in comm_select.c first!
6570 DOC_END
6571
6572 NAME: accept_filter
6573 TYPE: string
6574 DEFAULT: none
6575 LOC: Config.accept_filter
6576 DOC_START
6577 FreeBSD:
6578
6579 The name of an accept(2) filter to install on Squid's
6580 listen socket(s). This feature is perhaps specific to
6581 FreeBSD and requires support in the kernel.
6582
6583 The 'httpready' filter delays delivering new connections
6584 to Squid until a full HTTP request has been received.
6585 See the accf_http(9) man page for details.
6586
6587 The 'dataready' filter delays delivering new connections
6588 to Squid until there is some data to process.
6589 See the accf_dataready(9) man page for details.
6590
6591 Linux:
6592
6593 The 'data' filter delays delivering of new connections
6594 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
6595 You may optionally specify a number of seconds to wait by
6596 'data=N' where N is the number of seconds. Defaults to 30
6597 if not specified. See the tcp(7) man page for details.
6598 EXAMPLE:
6599 # FreeBSD
6600 accept_filter httpready
6601 # Linux
6602 accept_filter data
6603 DOC_END
6604
6605 NAME: client_ip_max_connections
6606 TYPE: int
6607 LOC: Config.client_ip_max_connections
6608 DEFAULT: -1
6609 DOC_START
6610 Set an absolute limit on the number of connections a single
6611 client IP can use. Any more than this and Squid will begin to drop
6612 new connections from the client until it closes some links.
6613
6614 Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
6615 connections from the client. For finer control use the ACL access controls.
6616
6617 Requires client_db to be enabled (the default).
6618
6619 WARNING: This may noticably slow down traffic received via external proxies
6620 or NAT devices and cause them to rebound error messages back to their clients.
6621 DOC_END
6622
6623 NAME: tcp_recv_bufsize
6624 COMMENT: (bytes)
6625 TYPE: b_size_t
6626 DEFAULT: 0 bytes
6627 LOC: Config.tcpRcvBufsz
6628 DOC_START
6629 Size of receive buffer to set for TCP sockets. Probably just
6630 as easy to change your kernel's default. Set to zero to use
6631 the default buffer size.
6632 DOC_END
6633
6634 COMMENT_START
6635 ICAP OPTIONS
6636 -----------------------------------------------------------------------------
6637 COMMENT_END
6638
6639 NAME: icap_enable
6640 TYPE: onoff
6641 IFDEF: ICAP_CLIENT
6642 COMMENT: on|off
6643 LOC: Adaptation::Icap::TheConfig.onoff
6644 DEFAULT: off
6645 DOC_START
6646 If you want to enable the ICAP module support, set this to on.
6647 DOC_END
6648
6649 NAME: icap_connect_timeout
6650 TYPE: time_t
6651 DEFAULT: none
6652 LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
6653 IFDEF: ICAP_CLIENT
6654 DOC_START
6655 This parameter specifies how long to wait for the TCP connect to
6656 the requested ICAP server to complete before giving up and either
6657 terminating the HTTP transaction or bypassing the failure.
6658
6659 The default for optional services is peer_connect_timeout.
6660 The default for essential services is connect_timeout.
6661 If this option is explicitly set, its value applies to all services.
6662 DOC_END
6663
6664 NAME: icap_io_timeout
6665 COMMENT: time-units
6666 TYPE: time_t
6667 DEFAULT: none
6668 LOC: Adaptation::Icap::TheConfig.io_timeout_raw
6669 IFDEF: ICAP_CLIENT
6670 DOC_START
6671 This parameter specifies how long to wait for an I/O activity on
6672 an established, active ICAP connection before giving up and
6673 either terminating the HTTP transaction or bypassing the
6674 failure.
6675
6676 The default is read_timeout.
6677 DOC_END
6678
6679 NAME: icap_service_failure_limit
6680 COMMENT: limit [in memory-depth time-units]
6681 TYPE: icap_service_failure_limit
6682 IFDEF: ICAP_CLIENT
6683 LOC: Adaptation::Icap::TheConfig
6684 DEFAULT: 10
6685 DOC_START
6686 The limit specifies the number of failures that Squid tolerates
6687 when establishing a new TCP connection with an ICAP service. If
6688 the number of failures exceeds the limit, the ICAP service is
6689 not used for new ICAP requests until it is time to refresh its
6690 OPTIONS.
6691
6692 A negative value disables the limit. Without the limit, an ICAP
6693 service will not be considered down due to connectivity failures
6694 between ICAP OPTIONS requests.
6695
6696 Squid forgets ICAP service failures older than the specified
6697 value of memory-depth. The memory fading algorithm
6698 is approximate because Squid does not remember individual
6699 errors but groups them instead, splitting the option
6700 value into ten time slots of equal length.
6701
6702 When memory-depth is 0 and by default this option has no
6703 effect on service failure expiration.
6704
6705 Squid always forgets failures when updating service settings
6706 using an ICAP OPTIONS transaction, regardless of this option
6707 setting.
6708
6709 For example,
6710 # suspend service usage after 10 failures in 5 seconds:
6711 icap_service_failure_limit 10 in 5 seconds
6712 DOC_END
6713
6714 NAME: icap_service_revival_delay
6715 TYPE: int
6716 IFDEF: ICAP_CLIENT
6717 LOC: Adaptation::Icap::TheConfig.service_revival_delay
6718 DEFAULT: 180
6719 DOC_START
6720 The delay specifies the number of seconds to wait after an ICAP
6721 OPTIONS request failure before requesting the options again. The
6722 failed ICAP service is considered "down" until fresh OPTIONS are
6723 fetched.
6724
6725 The actual delay cannot be smaller than the hardcoded minimum
6726 delay of 30 seconds.
6727 DOC_END
6728
6729 NAME: icap_preview_enable
6730 TYPE: onoff
6731 IFDEF: ICAP_CLIENT
6732 COMMENT: on|off
6733 LOC: Adaptation::Icap::TheConfig.preview_enable
6734 DEFAULT: on
6735 DOC_START
6736 The ICAP Preview feature allows the ICAP server to handle the
6737 HTTP message by looking only at the beginning of the message body
6738 or even without receiving the body at all. In some environments,
6739 previews greatly speedup ICAP processing.
6740
6741 During an ICAP OPTIONS transaction, the server may tell Squid what
6742 HTTP messages should be previewed and how big the preview should be.
6743 Squid will not use Preview if the server did not request one.
6744
6745 To disable ICAP Preview for all ICAP services, regardless of
6746 individual ICAP server OPTIONS responses, set this option to "off".
6747 Example:
6748 icap_preview_enable off
6749 DOC_END
6750
6751 NAME: icap_preview_size
6752 TYPE: int
6753 IFDEF: ICAP_CLIENT
6754 LOC: Adaptation::Icap::TheConfig.preview_size
6755 DEFAULT: -1
6756 DOC_START
6757 The default size of preview data to be sent to the ICAP server.
6758 -1 means no preview. This value might be overwritten on a per server
6759 basis by OPTIONS requests.
6760 DOC_END
6761
6762 NAME: icap_206_enable
6763 TYPE: onoff
6764 IFDEF: ICAP_CLIENT
6765 COMMENT: on|off
6766 LOC: Adaptation::Icap::TheConfig.allow206_enable
6767 DEFAULT: on
6768 DOC_START
6769 206 (Partial Content) responses is an ICAP extension that allows the
6770 ICAP agents to optionally combine adapted and original HTTP message
6771 content. The decision to combine is postponed until the end of the
6772 ICAP response. Squid supports Partial Content extension by default.
6773
6774 Activation of the Partial Content extension is negotiated with each
6775 ICAP service during OPTIONS exchange. Most ICAP servers should handle
6776 negotation correctly even if they do not support the extension, but
6777 some might fail. To disable Partial Content support for all ICAP
6778 services and to avoid any negotiation, set this option to "off".
6779
6780 Example:
6781 icap_206_enable off
6782 DOC_END
6783
6784 NAME: icap_default_options_ttl
6785 TYPE: int
6786 IFDEF: ICAP_CLIENT
6787 LOC: Adaptation::Icap::TheConfig.default_options_ttl
6788 DEFAULT: 60
6789 DOC_START
6790 The default TTL value for ICAP OPTIONS responses that don't have
6791 an Options-TTL header.
6792 DOC_END
6793
6794 NAME: icap_persistent_connections
6795 TYPE: onoff
6796 IFDEF: ICAP_CLIENT
6797 COMMENT: on|off
6798 LOC: Adaptation::Icap::TheConfig.reuse_connections
6799 DEFAULT: on
6800 DOC_START
6801 Whether or not Squid should use persistent connections to
6802 an ICAP server.
6803 DOC_END
6804
6805 NAME: adaptation_send_client_ip icap_send_client_ip
6806 TYPE: onoff
6807 IFDEF: USE_ADAPTATION
6808 COMMENT: on|off
6809 LOC: Adaptation::Config::send_client_ip
6810 DEFAULT: off
6811 DOC_START
6812 If enabled, Squid shares HTTP client IP information with adaptation
6813 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
6814 For eCAP, Squid sets the libecap::metaClientIp transaction option.
6815
6816 See also: adaptation_uses_indirect_client
6817 DOC_END
6818
6819 NAME: adaptation_send_username icap_send_client_username
6820 TYPE: onoff
6821 IFDEF: USE_ADAPTATION
6822 COMMENT: on|off
6823 LOC: Adaptation::Config::send_username
6824 DEFAULT: off
6825 DOC_START
6826 This sends authenticated HTTP client username (if available) to
6827 the adaptation service.
6828
6829 For ICAP, the username value is encoded based on the
6830 icap_client_username_encode option and is sent using the header
6831 specified by the icap_client_username_header option.
6832 DOC_END
6833
6834 NAME: icap_client_username_header
6835 TYPE: string
6836 IFDEF: ICAP_CLIENT
6837 LOC: Adaptation::Icap::TheConfig.client_username_header
6838 DEFAULT: X-Client-Username
6839 DOC_START
6840 ICAP request header name to use for adaptation_send_username.
6841 DOC_END
6842
6843 NAME: icap_client_username_encode
6844 TYPE: onoff
6845 IFDEF: ICAP_CLIENT
6846 COMMENT: on|off
6847 LOC: Adaptation::Icap::TheConfig.client_username_encode
6848 DEFAULT: off
6849 DOC_START
6850 Whether to base64 encode the authenticated client username.
6851 DOC_END
6852
6853 NAME: icap_service
6854 TYPE: icap_service_type
6855 IFDEF: ICAP_CLIENT
6856 LOC: Adaptation::Icap::TheConfig
6857 DEFAULT: none
6858 DOC_START
6859 Defines a single ICAP service using the following format:
6860
6861 icap_service id vectoring_point uri [option ...]
6862
6863 id: ID
6864 an opaque identifier or name which is used to direct traffic to
6865 this specific service. Must be unique among all adaptation
6866 services in squid.conf.
6867
6868 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
6869 This specifies at which point of transaction processing the
6870 ICAP service should be activated. *_postcache vectoring points
6871 are not yet supported.
6872
6873 uri: icap://servername:port/servicepath
6874 ICAP server and service location.
6875
6876 ICAP does not allow a single service to handle both REQMOD and RESPMOD
6877 transactions. Squid does not enforce that requirement. You can specify
6878 services with the same service_url and different vectoring_points. You
6879 can even specify multiple identical services as long as their
6880 service_names differ.
6881
6882
6883 Service options are separated by white space. ICAP services support
6884 the following name=value options:
6885
6886 bypass=on|off|1|0
6887 If set to 'on' or '1', the ICAP service is treated as
6888 optional. If the service cannot be reached or malfunctions,
6889 Squid will try to ignore any errors and process the message as
6890 if the service was not enabled. No all ICAP errors can be
6891 bypassed. If set to 0, the ICAP service is treated as
6892 essential and all ICAP errors will result in an error page
6893 returned to the HTTP client.
6894
6895 Bypass is off by default: services are treated as essential.
6896
6897 routing=on|off|1|0
6898 If set to 'on' or '1', the ICAP service is allowed to
6899 dynamically change the current message adaptation plan by
6900 returning a chain of services to be used next. The services
6901 are specified using the X-Next-Services ICAP response header
6902 value, formatted as a comma-separated list of service names.
6903 Each named service should be configured in squid.conf. Other
6904 services are ignored. An empty X-Next-Services value results
6905 in an empty plan which ends the current adaptation.
6906
6907 Dynamic adaptation plan may cross or cover multiple supported
6908 vectoring points in their natural processing order.
6909
6910 Routing is not allowed by default: the ICAP X-Next-Services
6911 response header is ignored.
6912
6913 ipv6=on|off
6914 Only has effect on split-stack systems. The default on those systems
6915 is to use IPv4-only connections. When set to 'on' this option will
6916 make Squid use IPv6-only connections to contact this ICAP service.
6917
6918 on-overload=block|bypass|wait|force
6919 If the service Max-Connections limit has been reached, do
6920 one of the following for each new ICAP transaction:
6921 * block: send an HTTP error response to the client
6922 * bypass: ignore the "over-connected" ICAP service
6923 * wait: wait (in a FIFO queue) for an ICAP connection slot
6924 * force: proceed, ignoring the Max-Connections limit
6925
6926 In SMP mode with N workers, each worker assumes the service
6927 connection limit is Max-Connections/N, even though not all
6928 workers may use a given service.
6929
6930 The default value is "bypass" if service is bypassable,
6931 otherwise it is set to "wait".
6932
6933
6934 max-conn=number
6935 Use the given number as the Max-Connections limit, regardless
6936 of the Max-Connections value given by the service, if any.
6937
6938 Older icap_service format without optional named parameters is
6939 deprecated but supported for backward compatibility.
6940
6941 Example:
6942 icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
6943 icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
6944 DOC_END
6945
6946 NAME: icap_class
6947 TYPE: icap_class_type
6948 IFDEF: ICAP_CLIENT
6949 LOC: none
6950 DEFAULT: none
6951 DOC_START
6952 This deprecated option was documented to define an ICAP service
6953 chain, even though it actually defined a set of similar, redundant
6954 services, and the chains were not supported.
6955
6956 To define a set of redundant services, please use the
6957 adaptation_service_set directive. For service chains, use
6958 adaptation_service_chain.
6959 DOC_END
6960
6961 NAME: icap_access
6962 TYPE: icap_access_type
6963 IFDEF: ICAP_CLIENT
6964 LOC: none
6965 DEFAULT: none
6966 DOC_START
6967 This option is deprecated. Please use adaptation_access, which
6968 has the same ICAP functionality, but comes with better
6969 documentation, and eCAP support.
6970 DOC_END
6971
6972 COMMENT_START
6973 eCAP OPTIONS
6974 -----------------------------------------------------------------------------
6975 COMMENT_END
6976
6977 NAME: ecap_enable
6978 TYPE: onoff
6979 IFDEF: USE_ECAP
6980 COMMENT: on|off
6981 LOC: Adaptation::Ecap::TheConfig.onoff
6982 DEFAULT: off
6983 DOC_START
6984 Controls whether eCAP support is enabled.
6985 DOC_END
6986
6987 NAME: ecap_service
6988 TYPE: ecap_service_type
6989 IFDEF: USE_ECAP
6990 LOC: Adaptation::Ecap::TheConfig
6991 DEFAULT: none
6992 DOC_START
6993 Defines a single eCAP service
6994
6995 ecap_service id vectoring_point uri [option ...]
6996
6997 id: ID
6998 an opaque identifier or name which is used to direct traffic to
6999 this specific service. Must be unique among all adaptation
7000 services in squid.conf.
7001
7002 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7003 This specifies at which point of transaction processing the
7004 eCAP service should be activated. *_postcache vectoring points
7005 are not yet supported.
7006
7007 uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
7008 Squid uses the eCAP service URI to match this configuration
7009 line with one of the dynamically loaded services. Each loaded
7010 eCAP service must have a unique URI. Obtain the right URI from
7011 the service provider.
7012
7013
7014 Service options are separated by white space. eCAP services support
7015 the following name=value options:
7016
7017 bypass=on|off|1|0
7018 If set to 'on' or '1', the eCAP service is treated as optional.
7019 If the service cannot be reached or malfunctions, Squid will try
7020 to ignore any errors and process the message as if the service
7021 was not enabled. No all eCAP errors can be bypassed.
7022 If set to 'off' or '0', the eCAP service is treated as essential
7023 and all eCAP errors will result in an error page returned to the
7024 HTTP client.
7025
7026 Bypass is off by default: services are treated as essential.
7027
7028 routing=on|off|1|0
7029 If set to 'on' or '1', the eCAP service is allowed to
7030 dynamically change the current message adaptation plan by
7031 returning a chain of services to be used next.
7032
7033 Dynamic adaptation plan may cross or cover multiple supported
7034 vectoring points in their natural processing order.
7035
7036 Routing is not allowed by default.
7037
7038 Older ecap_service format without optional named parameters is
7039 deprecated but supported for backward compatibility.
7040
7041
7042 Example:
7043 ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
7044 ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
7045 DOC_END
7046
7047 NAME: loadable_modules
7048 TYPE: wordlist
7049 IFDEF: USE_LOADABLE_MODULES
7050 LOC: Config.loadable_module_names
7051 DEFAULT: none
7052 DOC_START
7053 Instructs Squid to load the specified dynamic module(s) or activate
7054 preloaded module(s).
7055 Example:
7056 loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
7057 DOC_END
7058
7059 COMMENT_START
7060 MESSAGE ADAPTATION OPTIONS
7061 -----------------------------------------------------------------------------
7062 COMMENT_END
7063
7064 NAME: adaptation_service_set
7065 TYPE: adaptation_service_set_type
7066 IFDEF: USE_ADAPTATION
7067 LOC: none
7068 DEFAULT: none
7069 DOC_START
7070
7071 Configures an ordered set of similar, redundant services. This is
7072 useful when hot standby or backup adaptation servers are available.
7073
7074 adaptation_service_set set_name service_name1 service_name2 ...
7075
7076 The named services are used in the set declaration order. The first
7077 applicable adaptation service from the set is used first. The next
7078 applicable service is tried if and only if the transaction with the
7079 previous service fails and the message waiting to be adapted is still
7080 intact.
7081
7082 When adaptation starts, broken services are ignored as if they were
7083 not a part of the set. A broken service is a down optional service.
7084
7085 The services in a set must be attached to the same vectoring point
7086 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7087
7088 If all services in a set are optional then adaptation failures are
7089 bypassable. If all services in the set are essential, then a
7090 transaction failure with one service may still be retried using
7091 another service from the set, but when all services fail, the master
7092 transaction fails as well.
7093
7094 A set may contain a mix of optional and essential services, but that
7095 is likely to lead to surprising results because broken services become
7096 ignored (see above), making previously bypassable failures fatal.
7097 Technically, it is the bypassability of the last failed service that
7098 matters.
7099
7100 See also: adaptation_access adaptation_service_chain
7101
7102 Example:
7103 adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
7104 adaptation service_set svcLogger loggerLocal loggerRemote
7105 DOC_END
7106
7107 NAME: adaptation_service_chain
7108 TYPE: adaptation_service_chain_type
7109 IFDEF: USE_ADAPTATION
7110 LOC: none
7111 DEFAULT: none
7112 DOC_START
7113
7114 Configures a list of complementary services that will be applied
7115 one-by-one, forming an adaptation chain or pipeline. This is useful
7116 when Squid must perform different adaptations on the same message.
7117
7118 adaptation_service_chain chain_name service_name1 svc_name2 ...
7119
7120 The named services are used in the chain declaration order. The first
7121 applicable adaptation service from the chain is used first. The next
7122 applicable service is applied to the successful adaptation results of
7123 the previous service in the chain.
7124
7125 When adaptation starts, broken services are ignored as if they were
7126 not a part of the chain. A broken service is a down optional service.
7127
7128 Request satisfaction terminates the adaptation chain because Squid
7129 does not currently allow declaration of RESPMOD services at the
7130 "reqmod_precache" vectoring point (see icap_service or ecap_service).
7131
7132 The services in a chain must be attached to the same vectoring point
7133 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7134
7135 A chain may contain a mix of optional and essential services. If an
7136 essential adaptation fails (or the failure cannot be bypassed for
7137 other reasons), the master transaction fails. Otherwise, the failure
7138 is bypassed as if the failed adaptation service was not in the chain.
7139
7140 See also: adaptation_access adaptation_service_set
7141
7142 Example:
7143 adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
7144 DOC_END
7145
7146 NAME: adaptation_access
7147 TYPE: adaptation_access_type
7148 IFDEF: USE_ADAPTATION
7149 LOC: none
7150 DEFAULT: none
7151 DOC_START
7152 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
7153
7154 adaptation_access service_name allow|deny [!]aclname...
7155 adaptation_access set_name allow|deny [!]aclname...
7156
7157 At each supported vectoring point, the adaptation_access
7158 statements are processed in the order they appear in this
7159 configuration file. Statements pointing to the following services
7160 are ignored (i.e., skipped without checking their ACL):
7161
7162 - services serving different vectoring points
7163 - "broken-but-bypassable" services
7164 - "up" services configured to ignore such transactions
7165 (e.g., based on the ICAP Transfer-Ignore header).
7166
7167 When a set_name is used, all services in the set are checked
7168 using the same rules, to find the first applicable one. See
7169 adaptation_service_set for details.
7170
7171 If an access list is checked and there is a match, the
7172 processing stops: For an "allow" rule, the corresponding
7173 adaptation service is used for the transaction. For a "deny"
7174 rule, no adaptation service is activated.
7175
7176 It is currently not possible to apply more than one adaptation
7177 service at the same vectoring point to the same HTTP transaction.
7178
7179 See also: icap_service and ecap_service
7180
7181 Example:
7182 adaptation_access service_1 allow all
7183 DOC_END
7184
7185 NAME: adaptation_service_iteration_limit
7186 TYPE: int
7187 IFDEF: USE_ADAPTATION
7188 LOC: Adaptation::Config::service_iteration_limit
7189 DEFAULT: 16
7190 DOC_START
7191 Limits the number of iterations allowed when applying adaptation
7192 services to a message. If your longest adaptation set or chain
7193 may have more than 16 services, increase the limit beyond its
7194 default value of 16. If detecting infinite iteration loops sooner
7195 is critical, make the iteration limit match the actual number
7196 of services in your longest adaptation set or chain.
7197
7198 Infinite adaptation loops are most likely with routing services.
7199
7200 See also: icap_service routing=1
7201 DOC_END
7202
7203 NAME: adaptation_masterx_shared_names
7204 TYPE: string
7205 IFDEF: USE_ADAPTATION
7206 LOC: Adaptation::Config::masterx_shared_name
7207 DEFAULT: none
7208 DOC_START
7209 For each master transaction (i.e., the HTTP request and response
7210 sequence, including all related ICAP and eCAP exchanges), Squid
7211 maintains a table of metadata. The table entries are (name, value)
7212 pairs shared among eCAP and ICAP exchanges. The table is destroyed
7213 with the master transaction.
7214
7215 This option specifies the table entry names that Squid must accept
7216 from and forward to the adaptation transactions.
7217
7218 An ICAP REQMOD or RESPMOD transaction may set an entry in the
7219 shared table by returning an ICAP header field with a name
7220 specified in adaptation_masterx_shared_names.
7221
7222 An eCAP REQMOD or RESPMOD transaction may set an entry in the
7223 shared table by implementing the libecap::visitEachOption() API
7224 to provide an option with a name specified in
7225 adaptation_masterx_shared_names.
7226
7227 Squid will store and forward the set entry to subsequent adaptation
7228 transactions within the same master transaction scope.
7229
7230 Only one shared entry name is supported at this time.
7231
7232 Example:
7233 # share authentication information among ICAP services
7234 adaptation_masterx_shared_names X-Subscriber-ID
7235 DOC_END
7236
7237 NAME: adaptation_meta
7238 TYPE: adaptation_meta_type
7239 IFDEF: USE_ADAPTATION
7240 LOC: Adaptation::Config::metaHeaders
7241 DEFAULT: none
7242 DOC_START
7243 This option allows Squid administrator to add custom ICAP request
7244 headers or eCAP options to Squid ICAP requests or eCAP transactions.
7245 Use it to pass custom authentication tokens and other
7246 transaction-state related meta information to an ICAP/eCAP service.
7247
7248 The addition of a meta header is ACL-driven:
7249 adaptation_meta name value [!]aclname ...
7250
7251 Processing for a given header name stops after the first ACL list match.
7252 Thus, it is impossible to add two headers with the same name. If no ACL
7253 lists match for a given header name, no such header is added. For
7254 example:
7255
7256 # do not debug transactions except for those that need debugging
7257 adaptation_meta X-Debug 1 needs_debugging
7258
7259 # log all transactions except for those that must remain secret
7260 adaptation_meta X-Log 1 !keep_secret
7261
7262 # mark transactions from users in the "G 1" group
7263 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
7264
7265 The "value" parameter may be a regular squid.conf token or a "double
7266 quoted string". Within the quoted string, use backslash (\) to escape
7267 any character, which is currently only useful for escaping backslashes
7268 and double quotes. For example,
7269 "this string has one backslash (\\) and two \"quotes\""
7270 DOC_END
7271
7272 NAME: icap_retry
7273 TYPE: acl_access
7274 IFDEF: ICAP_CLIENT
7275 LOC: Adaptation::Icap::TheConfig.repeat
7276 DEFAULT_IF_NONE: deny all
7277 DOC_START
7278 This ACL determines which retriable ICAP transactions are
7279 retried. Transactions that received a complete ICAP response
7280 and did not have to consume or produce HTTP bodies to receive
7281 that response are usually retriable.
7282
7283 icap_retry allow|deny [!]aclname ...
7284
7285 Squid automatically retries some ICAP I/O timeouts and errors
7286 due to persistent connection race conditions.
7287
7288 See also: icap_retry_limit
7289 DOC_END
7290
7291 NAME: icap_retry_limit
7292 TYPE: int
7293 IFDEF: ICAP_CLIENT
7294 LOC: Adaptation::Icap::TheConfig.repeat_limit
7295 DEFAULT: 0
7296 DOC_START
7297 Limits the number of retries allowed. When set to zero (default),
7298 no retries are allowed.
7299
7300 Communication errors due to persistent connection race
7301 conditions are unavoidable, automatically retried, and do not
7302 count against this limit.
7303
7304 See also: icap_retry
7305 DOC_END
7306
7307
7308 COMMENT_START
7309 DNS OPTIONS
7310 -----------------------------------------------------------------------------
7311 COMMENT_END
7312
7313 NAME: check_hostnames
7314 TYPE: onoff
7315 DEFAULT: off
7316 LOC: Config.onoff.check_hostnames
7317 DOC_START
7318 For security and stability reasons Squid can check
7319 hostnames for Internet standard RFC compliance. If you want
7320 Squid to perform these checks turn this directive on.
7321 DOC_END
7322
7323 NAME: allow_underscore
7324 TYPE: onoff
7325 DEFAULT: on
7326 LOC: Config.onoff.allow_underscore
7327 DOC_START
7328 Underscore characters is not strictly allowed in Internet hostnames
7329 but nevertheless used by many sites. Set this to off if you want
7330 Squid to be strict about the standard.
7331 This check is performed only when check_hostnames is set to on.
7332 DOC_END
7333
7334 NAME: cache_dns_program
7335 TYPE: string
7336 IFDEF: USE_DNSHELPER
7337 DEFAULT: @DEFAULT_DNSSERVER@
7338 LOC: Config.Program.dnsserver
7339 DOC_START
7340 Specify the location of the executable for dnslookup process.
7341 DOC_END
7342
7343 NAME: dns_children
7344 TYPE: HelperChildConfig
7345 IFDEF: USE_DNSHELPER
7346 DEFAULT: 32 startup=1 idle=1
7347 LOC: Config.dnsChildren
7348 DOC_START
7349 The maximum number of processes spawn to service DNS name lookups.
7350 If you limit it too few Squid will have to wait for them to process
7351 a backlog of requests, slowing it down. If you allow too many they
7352 will use RAM and other system resources noticably.
7353 The maximum this may be safely set to is 32.
7354
7355 The startup= and idle= options allow some measure of skew in your
7356 tuning.
7357
7358 startup=
7359
7360 Sets a minimum of how many processes are to be spawned when Squid
7361 starts or reconfigures. When set to zero the first request will
7362 cause spawning of the first child process to handle it.
7363
7364 Starting too few will cause an initial slowdown in traffic as Squid
7365 attempts to simultaneously spawn enough processes to cope.
7366
7367 idle=
7368
7369 Sets a minimum of how many processes Squid is to try and keep available
7370 at all times. When traffic begins to rise above what the existing
7371 processes can handle this many more will be spawned up to the maximum
7372 configured. A minimum setting of 1 is required.
7373 DOC_END
7374
7375 NAME: dns_retransmit_interval
7376 TYPE: time_msec
7377 DEFAULT: 5 seconds
7378 LOC: Config.Timeout.idns_retransmit
7379 IFDEF: !USE_DNSHELPER
7380 DOC_START
7381 Initial retransmit interval for DNS queries. The interval is
7382 doubled each time all configured DNS servers have been tried.
7383 DOC_END
7384
7385 NAME: dns_timeout
7386 TYPE: time_msec
7387 DEFAULT: 30 seconds
7388 LOC: Config.Timeout.idns_query
7389 IFDEF: !USE_DNSHELPER
7390 DOC_START
7391 DNS Query timeout. If no response is received to a DNS query
7392 within this time all DNS servers for the queried domain
7393 are assumed to be unavailable.
7394 DOC_END
7395
7396 NAME: dns_packet_max
7397 TYPE: b_ssize_t
7398 DEFAULT: none
7399 LOC: Config.dns.packet_max
7400 IFDEF: !USE_DNSHELPER
7401 DOC_START
7402 Maximum number of bytes packet size to advertise via EDNS.
7403 Set to "none" to disable EDNS large packet support.
7404
7405 For legacy reasons DNS UDP replies will default to 512 bytes which
7406 is too small for many responses. EDNS provides a means for Squid to
7407 negotiate receiving larger responses back immediately without having
7408 to failover with repeat requests. Responses larger than this limit
7409 will retain the old behaviour of failover to TCP DNS.
7410
7411 Squid has no real fixed limit internally, but allowing packet sizes
7412 over 1500 bytes requires network jumbogram support and is usually not
7413 necessary.
7414
7415 WARNING: The RFC also indicates that some older resolvers will reply
7416 with failure of the whole request if the extension is added. Some
7417 resolvers have already been identified which will reply with mangled
7418 EDNS response on occasion. Usually in response to many-KB jumbogram
7419 sizes being advertised by Squid.
7420 Squid will currently treat these both as an unable-to-resolve domain
7421 even if it would be resolvable without EDNS.
7422 DOC_END
7423
7424 NAME: dns_defnames
7425 COMMENT: on|off
7426 TYPE: onoff
7427 DEFAULT: off
7428 LOC: Config.onoff.res_defnames
7429 DOC_START
7430 Normally the RES_DEFNAMES resolver option is disabled
7431 (see res_init(3)). This prevents caches in a hierarchy
7432 from interpreting single-component hostnames locally. To allow
7433 Squid to handle single-component names, enable this option.
7434 DOC_END
7435
7436 NAME: dns_nameservers
7437 TYPE: wordlist
7438 DEFAULT: none
7439 LOC: Config.dns_nameservers
7440 DOC_START
7441 Use this if you want to specify a list of DNS name servers
7442 (IP addresses) to use instead of those given in your
7443 /etc/resolv.conf file.
7444 On Windows platforms, if no value is specified here or in
7445 the /etc/resolv.conf file, the list of DNS name servers are
7446 taken from the Windows registry, both static and dynamic DHCP
7447 configurations are supported.
7448
7449 Example: dns_nameservers 10.0.0.1 192.172.0.4
7450 DOC_END
7451
7452 NAME: hosts_file
7453 TYPE: string
7454 DEFAULT: @DEFAULT_HOSTS@
7455 LOC: Config.etcHostsPath
7456 DOC_START
7457 Location of the host-local IP name-address associations
7458 database. Most Operating Systems have such a file on different
7459 default locations:
7460 - Un*X & Linux: /etc/hosts
7461 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
7462 (%SystemRoot% value install default is c:\winnt)
7463 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
7464 (%SystemRoot% value install default is c:\windows)
7465 - Windows 9x/Me: %windir%\hosts
7466 (%windir% value is usually c:\windows)
7467 - Cygwin: /etc/hosts
7468
7469 The file contains newline-separated definitions, in the
7470 form ip_address_in_dotted_form name [name ...] names are
7471 whitespace-separated. Lines beginning with an hash (#)
7472 character are comments.
7473
7474 The file is checked at startup and upon configuration.
7475 If set to 'none', it won't be checked.
7476 If append_domain is used, that domain will be added to
7477 domain-local (i.e. not containing any dot character) host
7478 definitions.
7479 DOC_END
7480
7481 NAME: append_domain
7482 TYPE: string
7483 LOC: Config.appendDomain
7484 DEFAULT: none
7485 DOC_START
7486 Appends local domain name to hostnames without any dots in
7487 them. append_domain must begin with a period.
7488
7489 Be warned there are now Internet names with no dots in
7490 them using only top-domain names, so setting this may
7491 cause some Internet sites to become unavailable.
7492
7493 Example:
7494 append_domain .yourdomain.com
7495 DOC_END
7496
7497 NAME: ignore_unknown_nameservers
7498 TYPE: onoff
7499 LOC: Config.onoff.ignore_unknown_nameservers
7500 DEFAULT: on
7501 IFDEF: !USE_DNSHELPER
7502 DOC_START
7503 By default Squid checks that DNS responses are received
7504 from the same IP addresses they are sent to. If they
7505 don't match, Squid ignores the response and writes a warning
7506 message to cache.log. You can allow responses from unknown
7507 nameservers by setting this option to 'off'.
7508 DOC_END
7509
7510 NAME: dns_v4_first
7511 TYPE: onoff
7512 DEFAULT: off
7513 LOC: Config.dns.v4_first
7514 IFDEF: !USE_DNSHELPER
7515 DOC_START
7516 With the IPv6 Internet being as fast or faster than IPv4 Internet
7517 for most networks Squid prefers to contact websites over IPv6.
7518
7519 This option reverses the order of preference to make Squid contact
7520 dual-stack websites over IPv4 first. Squid will still perform both
7521 IPv6 and IPv4 DNS lookups before connecting.
7522
7523 WARNING:
7524 This option will restrict the situations under which IPv6
7525 connectivity is used (and tested). Hiding network problems
7526 which would otherwise be detected and warned about.
7527 DOC_END
7528
7529 NAME: ipcache_size
7530 COMMENT: (number of entries)
7531 TYPE: int
7532 DEFAULT: 1024
7533 LOC: Config.ipcache.size
7534 DOC_NONE
7535
7536 NAME: ipcache_low
7537 COMMENT: (percent)
7538 TYPE: int
7539 DEFAULT: 90
7540 LOC: Config.ipcache.low
7541 DOC_NONE
7542
7543 NAME: ipcache_high
7544 COMMENT: (percent)
7545 TYPE: int
7546 DEFAULT: 95
7547 LOC: Config.ipcache.high
7548 DOC_START
7549 The size, low-, and high-water marks for the IP cache.
7550 DOC_END
7551
7552 NAME: fqdncache_size
7553 COMMENT: (number of entries)
7554 TYPE: int
7555 DEFAULT: 1024
7556 LOC: Config.fqdncache.size
7557 DOC_START
7558 Maximum number of FQDN cache entries.
7559 DOC_END
7560
7561 COMMENT_START
7562 MISCELLANEOUS
7563 -----------------------------------------------------------------------------
7564 COMMENT_END
7565
7566 NAME: memory_pools
7567 COMMENT: on|off
7568 TYPE: onoff
7569 DEFAULT: on
7570 LOC: Config.onoff.mem_pools
7571 DOC_START
7572 If set, Squid will keep pools of allocated (but unused) memory
7573 available for future use. If memory is a premium on your
7574 system and you believe your malloc library outperforms Squid
7575 routines, disable this.
7576 DOC_END
7577
7578 NAME: memory_pools_limit
7579 COMMENT: (bytes)
7580 TYPE: b_int64_t
7581 DEFAULT: 5 MB
7582 LOC: Config.MemPools.limit
7583 DOC_START
7584 Used only with memory_pools on:
7585 memory_pools_limit 50 MB
7586
7587 If set to a non-zero value, Squid will keep at most the specified
7588 limit of allocated (but unused) memory in memory pools. All free()
7589 requests that exceed this limit will be handled by your malloc
7590 library. Squid does not pre-allocate any memory, just safe-keeps
7591 objects that otherwise would be free()d. Thus, it is safe to set
7592 memory_pools_limit to a reasonably high value even if your
7593 configuration will use less memory.
7594
7595 If set to none, Squid will keep all memory it can. That is, there
7596 will be no limit on the total amount of memory used for safe-keeping.
7597
7598 To disable memory allocation optimization, do not set
7599 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
7600
7601 An overhead for maintaining memory pools is not taken into account
7602 when the limit is checked. This overhead is close to four bytes per
7603 object kept. However, pools may actually _save_ memory because of
7604 reduced memory thrashing in your malloc library.
7605 DOC_END
7606
7607 NAME: forwarded_for
7608 COMMENT: on|off|transparent|truncate|delete
7609 TYPE: string
7610 DEFAULT: on
7611 LOC: opt_forwarded_for
7612 DOC_START
7613 If set to "on", Squid will append your client's IP address
7614 in the HTTP requests it forwards. By default it looks like:
7615
7616 X-Forwarded-For: 192.1.2.3
7617
7618 If set to "off", it will appear as
7619
7620 X-Forwarded-For: unknown
7621
7622 If set to "transparent", Squid will not alter the
7623 X-Forwarded-For header in any way.
7624
7625 If set to "delete", Squid will delete the entire
7626 X-Forwarded-For header.
7627
7628 If set to "truncate", Squid will remove all existing
7629 X-Forwarded-For entries, and place the client IP as the sole entry.
7630 DOC_END
7631
7632 NAME: cachemgr_passwd
7633 TYPE: cachemgrpasswd
7634 DEFAULT: none
7635 LOC: Config.passwd_list
7636 DOC_START
7637 Specify passwords for cachemgr operations.
7638
7639 Usage: cachemgr_passwd password action action ...
7640
7641 Some valid actions are (see cache manager menu for a full list):
7642 5min
7643 60min
7644 asndb
7645 authenticator
7646 cbdata
7647 client_list
7648 comm_incoming
7649 config *
7650 counters
7651 delay
7652 digest_stats
7653 dns
7654 events
7655 filedescriptors
7656 fqdncache
7657 histograms
7658 http_headers
7659 info
7660 io
7661 ipcache
7662 mem
7663 menu
7664 netdb
7665 non_peers
7666 objects
7667 offline_toggle *
7668 pconn
7669 peer_select
7670 reconfigure *
7671 redirector
7672 refresh
7673 server_list
7674 shutdown *
7675 store_digest
7676 storedir
7677 utilization
7678 via_headers
7679 vm_objects
7680
7681 * Indicates actions which will not be performed without a
7682 valid password, others can be performed if not listed here.
7683
7684 To disable an action, set the password to "disable".
7685 To allow performing an action without a password, set the
7686 password to "none".
7687
7688 Use the keyword "all" to set the same password for all actions.
7689
7690 Example:
7691 cachemgr_passwd secret shutdown
7692 cachemgr_passwd lesssssssecret info stats/objects
7693 cachemgr_passwd disable all
7694 DOC_END
7695
7696 NAME: client_db
7697 COMMENT: on|off
7698 TYPE: onoff
7699 DEFAULT: on
7700 LOC: Config.onoff.client_db
7701 DOC_START
7702 If you want to disable collecting per-client statistics,
7703 turn off client_db here.
7704 DOC_END
7705
7706 NAME: refresh_all_ims
7707 COMMENT: on|off
7708 TYPE: onoff
7709 DEFAULT: off
7710 LOC: Config.onoff.refresh_all_ims
7711 DOC_START
7712 When you enable this option, squid will always check
7713 the origin server for an update when a client sends an
7714 If-Modified-Since request. Many browsers use IMS
7715 requests when the user requests a reload, and this
7716 ensures those clients receive the latest version.
7717
7718 By default (off), squid may return a Not Modified response
7719 based on the age of the cached version.
7720 DOC_END
7721
7722 NAME: reload_into_ims
7723 IFDEF: USE_HTTP_VIOLATIONS
7724 COMMENT: on|off
7725 TYPE: onoff
7726 DEFAULT: off
7727 LOC: Config.onoff.reload_into_ims
7728 DOC_START
7729 When you enable this option, client no-cache or ``reload''
7730 requests will be changed to If-Modified-Since requests.
7731 Doing this VIOLATES the HTTP standard. Enabling this
7732 feature could make you liable for problems which it
7733 causes.
7734
7735 see also refresh_pattern for a more selective approach.
7736 DOC_END
7737
7738 NAME: connect_retries
7739 TYPE: int
7740 LOC: Config.connect_retries
7741 DEFAULT: 0
7742 DOC_START
7743 This sets the maximum number of connection attempts made for each
7744 TCP connection. The connect_retries attempts must all still
7745 complete within the connection timeout period.
7746
7747 The default is not to re-try if the first connection attempt fails.
7748 The (not recommended) maximum is 10 tries.
7749
7750 A warning message will be generated if it is set to a too-high
7751 value and the configured value will be over-ridden.
7752
7753 Note: These re-tries are in addition to forward_max_tries
7754 which limit how many different addresses may be tried to find
7755 a useful server.
7756 DOC_END
7757
7758 NAME: retry_on_error
7759 TYPE: onoff
7760 LOC: Config.retry.onerror
7761 DEFAULT: off
7762 DOC_START
7763 If set to ON Squid will automatically retry requests when
7764 receiving an error response with status 403 (Forbidden),
7765 500 (Internal Error), 501 or 503 (Service not available).
7766 Status 502 and 504 (Gateway errors) are always retried.
7767
7768 This is mainly useful if you are in a complex cache hierarchy to
7769 work around access control errors.
7770
7771 NOTE: This retry will attempt to find another working destination.
7772 Which is different from the server which just failed.
7773 DOC_END
7774
7775 NAME: as_whois_server
7776 TYPE: string
7777 LOC: Config.as_whois_server
7778 DEFAULT: whois.ra.net
7779 DOC_START
7780 WHOIS server to query for AS numbers. NOTE: AS numbers are
7781 queried only when Squid starts up, not for every request.
7782 DOC_END
7783
7784 NAME: offline_mode
7785 TYPE: onoff
7786 LOC: Config.onoff.offline
7787 DEFAULT: off
7788 DOC_START
7789 Enable this option and Squid will never try to validate cached
7790 objects.
7791 DOC_END
7792
7793 NAME: uri_whitespace
7794 TYPE: uri_whitespace
7795 LOC: Config.uri_whitespace
7796 DEFAULT: strip
7797 DOC_START
7798 What to do with requests that have whitespace characters in the
7799 URI. Options:
7800
7801 strip: The whitespace characters are stripped out of the URL.
7802 This is the behavior recommended by RFC2396.
7803 deny: The request is denied. The user receives an "Invalid
7804 Request" message.
7805 allow: The request is allowed and the URI is not changed. The
7806 whitespace characters remain in the URI. Note the
7807 whitespace is passed to redirector processes if they
7808 are in use.
7809 encode: The request is allowed and the whitespace characters are
7810 encoded according to RFC1738. This could be considered
7811 a violation of the HTTP/1.1
7812 RFC because proxies are not allowed to rewrite URI's.
7813 chop: The request is allowed and the URI is chopped at the
7814 first whitespace. This might also be considered a
7815 violation.
7816 DOC_END
7817
7818 NAME: chroot
7819 TYPE: string
7820 LOC: Config.chroot_dir
7821 DEFAULT: none
7822 DOC_START
7823 Specifies a directory where Squid should do a chroot() while
7824 initializing. This also causes Squid to fully drop root
7825 privileges after initializing. This means, for example, if you
7826 use a HTTP port less than 1024 and try to reconfigure, you may
7827 get an error saying that Squid can not open the port.
7828 DOC_END
7829
7830 NAME: balance_on_multiple_ip
7831 TYPE: onoff
7832 LOC: Config.onoff.balance_on_multiple_ip
7833 DEFAULT: off
7834 DOC_START
7835 Modern IP resolvers in squid sort lookup results by preferred access.
7836 By default squid will use these IP in order and only rotates to
7837 the next listed when the most preffered fails.
7838
7839 Some load balancing servers based on round robin DNS have been
7840 found not to preserve user session state across requests
7841 to different IP addresses.
7842
7843 Enabling this directive Squid rotates IP's per request.
7844 DOC_END
7845
7846 NAME: pipeline_prefetch
7847 TYPE: onoff
7848 LOC: Config.onoff.pipeline_prefetch
7849 DEFAULT: off
7850 DOC_START
7851 To boost the performance of pipelined requests to closer
7852 match that of a non-proxied environment Squid can try to fetch
7853 up to two requests in parallel from a pipeline.
7854
7855 Defaults to off for bandwidth management and access logging
7856 reasons.
7857
7858 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
7859 DOC_END
7860
7861 NAME: high_response_time_warning
7862 TYPE: int
7863 COMMENT: (msec)
7864 LOC: Config.warnings.high_rptm
7865 DEFAULT: 0
7866 DOC_START
7867 If the one-minute median response time exceeds this value,
7868 Squid prints a WARNING with debug level 0 to get the
7869 administrators attention. The value is in milliseconds.
7870 DOC_END
7871
7872 NAME: high_page_fault_warning
7873 TYPE: int
7874 LOC: Config.warnings.high_pf
7875 DEFAULT: 0
7876 DOC_START
7877 If the one-minute average page fault rate exceeds this
7878 value, Squid prints a WARNING with debug level 0 to get
7879 the administrators attention. The value is in page faults
7880 per second.
7881 DOC_END
7882
7883 NAME: high_memory_warning
7884 TYPE: b_size_t
7885 LOC: Config.warnings.high_memory
7886 DEFAULT: 0 KB
7887 DOC_START
7888 If the memory usage (as determined by mallinfo) exceeds
7889 this amount, Squid prints a WARNING with debug level 0 to get
7890 the administrators attention.
7891 DOC_END
7892
7893 NAME: sleep_after_fork
7894 COMMENT: (microseconds)
7895 TYPE: int
7896 LOC: Config.sleep_after_fork
7897 DEFAULT: 0
7898 DOC_START
7899 When this is set to a non-zero value, the main Squid process
7900 sleeps the specified number of microseconds after a fork()
7901 system call. This sleep may help the situation where your
7902 system reports fork() failures due to lack of (virtual)
7903 memory. Note, however, if you have a lot of child
7904 processes, these sleep delays will add up and your
7905 Squid will not service requests for some amount of time
7906 until all the child processes have been started.
7907 On Windows value less then 1000 (1 milliseconds) are
7908 rounded to 1000.
7909 DOC_END
7910
7911 NAME: windows_ipaddrchangemonitor
7912 IFDEF: _SQUID_MSWIN_
7913 COMMENT: on|off
7914 TYPE: onoff
7915 DEFAULT: on
7916 LOC: Config.onoff.WIN32_IpAddrChangeMonitor
7917 DOC_START
7918 On Windows Squid by default will monitor IP address changes and will
7919 reconfigure itself after any detected event. This is very useful for
7920 proxies connected to internet with dial-up interfaces.
7921 In some cases (a Proxy server acting as VPN gateway is one) it could be
7922 desiderable to disable this behaviour setting this to 'off'.
7923 Note: after changing this, Squid service must be restarted.
7924 DOC_END
7925
7926 NAME: eui_lookup
7927 TYPE: onoff
7928 IFDEF: USE_SQUID_EUI
7929 DEFAULT: on
7930 LOC: Eui::TheConfig.euiLookup
7931 DOC_START
7932 Whether to lookup the EUI or MAC address of a connected client.
7933 DOC_END
7934
7935 NAME: max_filedescriptors max_filedesc
7936 TYPE: int
7937 DEFAULT: 0
7938 LOC: Config.max_filedescriptors
7939 DOC_START
7940 The maximum number of filedescriptors supported.
7941
7942 The default "0" means Squid inherits the current ulimit setting.
7943
7944 Note: Changing this requires a restart of Squid. Also
7945 not all comm loops supports large values.
7946 DOC_END
7947
7948 NAME: workers
7949 TYPE: int
7950 LOC: Config.workers
7951 DEFAULT: 1
7952 DOC_START
7953 Number of main Squid processes or "workers" to fork and maintain.
7954 0: "no daemon" mode, like running "squid -N ..."
7955 1: "no SMP" mode, start one main Squid process daemon (default)
7956 N: start N main Squid process daemons (i.e., SMP mode)
7957
7958 In SMP mode, each worker does nearly all what a single Squid daemon
7959 does (e.g., listen on http_port and forward HTTP requests).
7960 DOC_END
7961
7962 NAME: cpu_affinity_map
7963 TYPE: CpuAffinityMap
7964 LOC: Config.cpuAffinityMap
7965 DEFAULT: none
7966 DOC_START
7967 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
7968
7969 Sets 1:1 mapping between Squid processes and CPU cores. For example,
7970
7971 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
7972
7973 affects processes 1 through 4 only and places them on the first
7974 four even cores, starting with core #1.
7975
7976 CPU cores are numbered starting from 1. Requires support for
7977 sched_getaffinity(2) and sched_setaffinity(2) system calls.
7978
7979 Multiple cpu_affinity_map options are merged.
7980
7981 See also: workers
7982 DOC_END
7983
7984 EOF