1 /* $Cambridge: exim/src/src/acl.c,v 1.77 2007/06/20 14:13:39 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2007 */
8 /* See the file NOTICE for conditions of use and distribution. */
10 /* Code for handling Access Control Lists (ACLs) */
15 /* Default callout timeout */
17 #define CALLOUT_TIMEOUT_DEFAULT 30
19 /* ACL verb codes - keep in step with the table of verbs that follows */
21 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
26 static uschar *verbs[] =
27 { US"accept", US"defer", US"deny", US"discard", US"drop", US"require",
30 /* For each verb, the conditions for which "message" or "log_message" are used
31 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
32 "accept", the FAIL case is used only after "endpass", but that is selected in
35 static int msgcond[] = {
36 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
39 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
41 (1<<FAIL) | (1<<FAIL_DROP), /* require */
45 /* ACL condition and modifier codes - keep in step with the table that
46 follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
52 #ifdef EXPERIMENTAL_BRIGHTMAIL
58 #ifdef WITH_CONTENT_SCAN
62 #ifdef WITH_OLD_DEMIME
65 #ifdef EXPERIMENTAL_DOMAINKEYS
66 ACLC_DK_DOMAIN_SOURCE,
68 ACLC_DK_SENDER_DOMAINS,
69 ACLC_DK_SENDER_LOCAL_PARTS,
80 ACLC_LOG_REJECT_TARGET,
82 #ifdef WITH_CONTENT_SCAN
86 #ifdef WITH_CONTENT_SCAN
91 #ifdef WITH_CONTENT_SCAN
97 #ifdef WITH_CONTENT_SCAN
100 #ifdef EXPERIMENTAL_SPF
105 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
106 "message", "log_message", "log_reject_target", "logwrite", and "set" are
107 modifiers that look like conditions but always return TRUE. They are used for
108 their side effects. */
110 static uschar *conditions[] = {
114 #ifdef EXPERIMENTAL_BRIGHTMAIL
120 #ifdef WITH_CONTENT_SCAN
124 #ifdef WITH_OLD_DEMIME
127 #ifdef EXPERIMENTAL_DOMAINKEYS
128 US"dk_domain_source",
130 US"dk_sender_domains",
131 US"dk_sender_local_parts",
142 US"log_reject_target",
144 #ifdef WITH_CONTENT_SCAN
148 #ifdef WITH_CONTENT_SCAN
153 #ifdef WITH_CONTENT_SCAN
156 US"sender_domains", US"senders", US"set",
157 #ifdef WITH_CONTENT_SCAN
160 #ifdef EXPERIMENTAL_SPF
166 /* Return values from decode_control(); keep in step with the table of names
170 CONTROL_AUTH_UNADVERTISED,
171 #ifdef EXPERIMENTAL_BRIGHTMAIL
174 #ifdef EXPERIMENTAL_DOMAINKEYS
178 CONTROL_CASEFUL_LOCAL_PART,
179 CONTROL_CASELOWER_LOCAL_PART,
180 CONTROL_ENFORCE_SYNC,
181 CONTROL_NO_ENFORCE_SYNC,
185 CONTROL_SUPPRESS_LOCAL_FIXUPS,
186 #ifdef WITH_CONTENT_SCAN
187 CONTROL_NO_MBOX_UNSPOOL,
191 CONTROL_NO_MULTILINE,
192 CONTROL_NO_PIPELINING,
193 CONTROL_NO_DELAY_FLUSH,
194 CONTROL_NO_CALLOUT_FLUSH
197 /* ACL control names; keep in step with the table above! This list is used for
198 turning ids into names. The actual list of recognized names is in the variable
199 control_def controls_list[] below. The fact that there are two lists is a mess
200 and should be tidied up. */
202 static uschar *controls[] = {
203 US"allow_auth_unadvertised",
204 #ifdef EXPERIMENTAL_BRIGHTMAIL
207 #ifdef EXPERIMENTAL_DOMAINKEYS
211 US"caseful_local_part",
212 US"caselower_local_part",
218 US"suppress_local_fixups",
219 #ifdef WITH_CONTENT_SCAN
224 US"no_multiline_responses",
230 /* Flags to indicate for which conditions/modifiers a string expansion is done
231 at the outer level. In the other cases, expansion already occurs in the
232 checking functions. */
234 static uschar cond_expand_at_top[] = {
236 TRUE, /* add_header */
237 FALSE, /* authenticated */
238 #ifdef EXPERIMENTAL_BRIGHTMAIL
239 TRUE, /* bmi_optin */
241 TRUE, /* condition */
244 #ifdef WITH_CONTENT_SCAN
248 #ifdef WITH_OLD_DEMIME
251 #ifdef EXPERIMENTAL_DOMAINKEYS
252 TRUE, /* dk_domain_source */
253 TRUE, /* dk_policy */
254 TRUE, /* dk_sender_domains */
255 TRUE, /* dk_sender_local_parts */
256 TRUE, /* dk_senders */
257 TRUE, /* dk_status */
261 FALSE, /* encrypted */
264 FALSE, /* local_parts */
265 TRUE, /* log_message */
266 TRUE, /* log_reject_target */
268 #ifdef WITH_CONTENT_SCAN
272 #ifdef WITH_CONTENT_SCAN
273 TRUE, /* mime_regex */
275 TRUE, /* ratelimit */
276 FALSE, /* recipients */
277 #ifdef WITH_CONTENT_SCAN
280 FALSE, /* sender_domains */
283 #ifdef WITH_CONTENT_SCAN
286 #ifdef EXPERIMENTAL_SPF
292 /* Flags to identify the modifiers */
294 static uschar cond_modifiers[] = {
296 TRUE, /* add_header */
297 FALSE, /* authenticated */
298 #ifdef EXPERIMENTAL_BRIGHTMAIL
299 TRUE, /* bmi_optin */
301 FALSE, /* condition */
304 #ifdef WITH_CONTENT_SCAN
308 #ifdef WITH_OLD_DEMIME
311 #ifdef EXPERIMENTAL_DOMAINKEYS
312 FALSE, /* dk_domain_source */
313 FALSE, /* dk_policy */
314 FALSE, /* dk_sender_domains */
315 FALSE, /* dk_sender_local_parts */
316 FALSE, /* dk_senders */
317 FALSE, /* dk_status */
319 FALSE, /* dnslists */
321 FALSE, /* encrypted */
324 FALSE, /* local_parts */
325 TRUE, /* log_message */
326 TRUE, /* log_reject_target */
328 #ifdef WITH_CONTENT_SCAN
332 #ifdef WITH_CONTENT_SCAN
333 FALSE, /* mime_regex */
335 FALSE, /* ratelimit */
336 FALSE, /* recipients */
337 #ifdef WITH_CONTENT_SCAN
340 FALSE, /* sender_domains */
343 #ifdef WITH_CONTENT_SCAN
346 #ifdef EXPERIMENTAL_SPF
352 /* Bit map vector of which conditions and modifiers are not allowed at certain
353 times. For each condition, there's a bitmap of dis-allowed times. For some, it
354 is easier to specify the negation of a small number of allowed times. */
356 static unsigned int cond_forbids[] = {
360 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
361 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
362 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
363 (1<<ACL_WHERE_NOTSMTP_START)),
365 (1<<ACL_WHERE_NOTSMTP)| /* authenticated */
366 (1<<ACL_WHERE_NOTSMTP_START)|
367 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
369 #ifdef EXPERIMENTAL_BRIGHTMAIL
370 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
371 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
372 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
373 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
374 (1<<ACL_WHERE_MAILAUTH)|
375 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
376 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
377 (1<<ACL_WHERE_NOTSMTP_START),
384 /* Certain types of control are always allowed, so we let it through
385 always and check in the control processing itself. */
389 #ifdef WITH_CONTENT_SCAN
391 ~(1<<ACL_WHERE_MIME), /* decode */
396 #ifdef WITH_OLD_DEMIME
398 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
401 #ifdef EXPERIMENTAL_DOMAINKEYS
402 (1<<ACL_WHERE_AUTH)| /* dk_domain_source */
403 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
404 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
405 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
406 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
407 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
408 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
410 (1<<ACL_WHERE_AUTH)| /* dk_policy */
411 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
412 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
413 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
414 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
415 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
416 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
418 (1<<ACL_WHERE_AUTH)| /* dk_sender_domains */
419 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
420 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
421 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
422 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
423 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
424 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
426 (1<<ACL_WHERE_AUTH)| /* dk_sender_local_parts */
427 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
428 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
429 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
430 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
431 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
432 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
434 (1<<ACL_WHERE_AUTH)| /* dk_senders */
435 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
436 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
437 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
438 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
439 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
440 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
442 (1<<ACL_WHERE_AUTH)| /* dk_status */
443 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
444 (1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
445 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
446 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
447 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
448 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_NOTSMTP_START),
451 (1<<ACL_WHERE_NOTSMTP)| /* dnslists */
452 (1<<ACL_WHERE_NOTSMTP_START),
455 ~(1<<ACL_WHERE_RCPT), /* domains */
457 (1<<ACL_WHERE_NOTSMTP)| /* encrypted */
458 (1<<ACL_WHERE_CONNECT)|
459 (1<<ACL_WHERE_NOTSMTP_START)|
464 (1<<ACL_WHERE_NOTSMTP)| /* hosts */
465 (1<<ACL_WHERE_NOTSMTP_START),
468 ~(1<<ACL_WHERE_RCPT), /* local_parts */
472 0, /* log_reject_target */
476 #ifdef WITH_CONTENT_SCAN
478 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
483 #ifdef WITH_CONTENT_SCAN
485 ~(1<<ACL_WHERE_MIME), /* mime_regex */
491 ~(1<<ACL_WHERE_RCPT), /* recipients */
493 #ifdef WITH_CONTENT_SCAN
495 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
496 (1<<ACL_WHERE_MIME)),
499 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
501 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
502 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
503 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
505 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
507 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
508 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
509 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
513 #ifdef WITH_CONTENT_SCAN
515 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
518 #ifdef EXPERIMENTAL_SPF
519 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
521 (1<<ACL_WHERE_MAILAUTH)|
522 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
523 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
524 (1<<ACL_WHERE_NOTSMTP)|
525 (1<<ACL_WHERE_NOTSMTP_START),
528 /* Certain types of verify are always allowed, so we let it through
529 always and check in the verify function itself */
535 /* Bit map vector of which controls are not allowed at certain times. For
536 each control, there's a bitmap of dis-allowed times. For some, it is easier to
537 specify the negation of a small number of allowed times. */
539 static unsigned int control_forbids[] = {
541 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
543 #ifdef EXPERIMENTAL_BRIGHTMAIL
547 #ifdef EXPERIMENTAL_DOMAINKEYS
548 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dk_verify */
549 (1<<ACL_WHERE_NOTSMTP_START),
555 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
558 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
560 (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
561 (1<<ACL_WHERE_NOTSMTP_START),
563 (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
564 (1<<ACL_WHERE_NOTSMTP_START),
567 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
568 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
569 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
572 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
573 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
574 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
577 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
578 (1<<ACL_WHERE_PREDATA)),
581 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
582 (1<<ACL_WHERE_PREDATA)|
583 (1<<ACL_WHERE_NOTSMTP_START)),
585 #ifdef WITH_CONTENT_SCAN
587 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
588 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
589 (1<<ACL_WHERE_MIME)),
593 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
594 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
595 (1<<ACL_WHERE_MIME)),
598 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
599 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
600 (1<<ACL_WHERE_MIME)),
602 (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
603 (1<<ACL_WHERE_NOTSMTP_START),
605 (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
606 (1<<ACL_WHERE_NOTSMTP_START),
608 (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
609 (1<<ACL_WHERE_NOTSMTP_START),
611 (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
612 (1<<ACL_WHERE_NOTSMTP_START)
615 /* Structure listing various control arguments, with their characteristics. */
617 typedef struct control_def {
619 int value; /* CONTROL_xxx value */
620 BOOL has_option; /* Has /option(s) following */
623 static control_def controls_list[] = {
624 { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
625 #ifdef EXPERIMENTAL_BRIGHTMAIL
626 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
628 #ifdef EXPERIMENTAL_DOMAINKEYS
629 { US"dk_verify", CONTROL_DK_VERIFY, FALSE },
631 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
632 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
633 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
634 { US"freeze", CONTROL_FREEZE, TRUE },
635 { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
636 { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
637 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
638 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
639 { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
640 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
641 #ifdef WITH_CONTENT_SCAN
642 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
644 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
645 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
646 { US"submission", CONTROL_SUBMISSION, TRUE },
647 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE }
650 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
651 caches its result in a tree to avoid repeated DNS queries. The result is an
652 integer code which is used as an index into the following tables of
653 explanatory strings and verification return codes. */
655 static tree_node *csa_cache = NULL;
657 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
658 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
660 /* The acl_verify_csa() return code is translated into an acl_verify() return
661 code using the following table. It is OK unless the client is definitely not
662 authorized. This is because CSA is supposed to be optional for sending sites,
663 so recipients should not be too strict about checking it - especially because
664 DNS problems are quite likely to occur. It's possible to use $csa_status in
665 further ACL conditions to distinguish ok, unknown, and defer if required, but
666 the aim is to make the usual configuration simple. */
668 static int csa_return_code[] = {
670 FAIL, FAIL, FAIL, FAIL
673 static uschar *csa_status_string[] = {
674 US"unknown", US"ok", US"defer", US"defer",
675 US"fail", US"fail", US"fail", US"fail"
678 static uschar *csa_reason_string[] = {
681 US"deferred (SRV lookup failed)",
682 US"deferred (target address lookup failed)",
683 US"failed (explicit authorization required)",
684 US"failed (host name not authorized)",
685 US"failed (no authorized addresses)",
686 US"failed (client address mismatch)"
689 /* Enable recursion between acl_check_internal() and acl_check_condition() */
691 static int acl_check_internal(int, address_item *, uschar *, int, uschar **,
695 /*************************************************
696 * Pick out name from list *
697 *************************************************/
699 /* Use a binary chop method
706 Returns: offset in list, or -1 if not found
710 acl_checkname(uschar *name, uschar **list, int end)
716 int mid = (start + end)/2;
717 int c = Ustrcmp(name, list[mid]);
718 if (c == 0) return mid;
719 if (c < 0) end = mid; else start = mid + 1;
726 /*************************************************
727 * Read and parse one ACL *
728 *************************************************/
730 /* This function is called both from readconf in order to parse the ACLs in the
731 configuration file, and also when an ACL is encountered dynamically (e.g. as
732 the result of an expansion). It is given a function to call in order to
733 retrieve the lines of the ACL. This function handles skipping comments and
734 blank lines (where relevant).
737 func function to get next line of ACL
738 error where to put an error message
740 Returns: pointer to ACL, or NULL
741 NULL can be legal (empty ACL); in this case error will be NULL
745 acl_read(uschar *(*func)(void), uschar **error)
747 acl_block *yield = NULL;
748 acl_block **lastp = &yield;
749 acl_block *this = NULL;
750 acl_condition_block *cond;
751 acl_condition_block **condp = NULL;
756 while ((s = (*func)()) != NULL)
759 BOOL negated = FALSE;
760 uschar *saveline = s;
763 /* Conditions (but not verbs) are allowed to be negated by an initial
766 while (isspace(*s)) s++;
773 /* Read the name of a verb or a condition, or the start of a new ACL, which
774 can be started by a name, or by a macro definition. */
776 s = readconf_readname(name, sizeof(name), s);
777 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
779 /* If a verb is unrecognized, it may be another condition or modifier that
780 continues the previous verb. */
782 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
787 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
799 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
802 this = store_get(sizeof(acl_block));
804 lastp = &(this->next);
807 this->condition = NULL;
808 condp = &(this->condition);
809 if (*s == 0) continue; /* No condition on this line */
815 s = readconf_readname(name, sizeof(name), s); /* Condition name */
818 /* Handle a condition or modifier. */
820 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
823 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
828 /* The modifiers may not be negated */
830 if (negated && cond_modifiers[c])
832 *error = string_sprintf("ACL error: negation is not allowed with "
833 "\"%s\"", conditions[c]);
837 /* ENDPASS may occur only with ACCEPT or DISCARD. */
839 if (c == ACLC_ENDPASS &&
840 this->verb != ACL_ACCEPT &&
841 this->verb != ACL_DISCARD)
843 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
844 conditions[c], verbs[this->verb]);
848 cond = store_get(sizeof(acl_condition_block));
851 cond->u.negated = negated;
854 condp = &(cond->next);
856 /* The "set" modifier is different in that its argument is "name=value"
857 rather than just a value, and we can check the validity of the name, which
858 gives us a variable name to insert into the data block. The original ACL
859 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
860 extended to 20 of each type, but after that people successfully argued for
861 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
862 After that, we allow alphanumerics and underscores, but the first character
863 after c or m must be a digit or an underscore. This retains backwards
870 if (Ustrncmp(s, "acl_c", 5) != 0 &&
871 Ustrncmp(s, "acl_m", 5) != 0)
873 *error = string_sprintf("invalid variable name after \"set\" in ACL "
874 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
879 if (!isdigit(*endptr) && *endptr != '_')
881 *error = string_sprintf("invalid variable name after \"set\" in ACL "
882 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
887 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
889 if (!isalnum(*endptr) && *endptr != '_')
891 *error = string_sprintf("invalid character \"%c\" in variable name "
892 "in ACL modifier \"set %s\"", *endptr, s);
898 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
900 while (isspace(*s)) s++;
903 /* For "set", we are now positioned for the data. For the others, only
904 "endpass" has no data */
906 if (c != ACLC_ENDPASS)
910 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
911 cond_modifiers[c]? US"modifier" : US"condition");
914 while (isspace(*s)) s++;
915 cond->arg = string_copy(s);
924 /*************************************************
925 * Set up added header line(s) *
926 *************************************************/
928 /* This function is called by the add_header modifier, and also from acl_warn()
929 to implement the now-deprecated way of adding header lines using "message" on a
930 "warn" verb. The argument is treated as a sequence of header lines which are
931 added to a chain, provided there isn't an identical one already there.
933 Argument: string of header lines
938 setup_header(uschar *hstring)
941 int hlen = Ustrlen(hstring);
943 /* An empty string does nothing; otherwise add a final newline if necessary. */
945 if (hlen <= 0) return;
946 if (hstring[hlen-1] != '\n') hstring = string_sprintf("%s\n", hstring);
948 /* Loop for multiple header lines, taking care about continuations */
950 for (p = q = hstring; *p != 0; )
953 int newtype = htype_add_bot;
954 header_line **hptr = &acl_added_headers;
956 /* Find next header line within the string */
960 q = Ustrchr(q, '\n');
961 if (*(++q) != ' ' && *q != '\t') break;
964 /* If the line starts with a colon, interpret the instruction for where to
965 add it. This temporarily sets up a new type. */
969 if (strncmpic(p, US":after_received:", 16) == 0)
971 newtype = htype_add_rec;
974 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
976 newtype = htype_add_rfc;
979 else if (strncmpic(p, US":at_start:", 10) == 0)
981 newtype = htype_add_top;
984 else if (strncmpic(p, US":at_end:", 8) == 0)
986 newtype = htype_add_bot;
989 while (*p == ' ' || *p == '\t') p++;
992 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
993 to the front of it. */
995 for (s = p; s < q - 1; s++)
997 if (*s == ':' || !isgraph(*s)) break;
1000 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", q - p, p);
1003 /* See if this line has already been added */
1005 while (*hptr != NULL)
1007 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
1008 hptr = &((*hptr)->next);
1011 /* Add if not previously present */
1015 header_line *h = store_get(sizeof(header_line));
1024 /* Advance for next header line within the string */
1033 /*************************************************
1035 *************************************************/
1037 /* This function is called when a WARN verb's conditions are true. It adds to
1038 the message's headers, and/or writes information to the log. In each case, this
1039 only happens once (per message for headers, per connection for log).
1041 ** NOTE: The header adding action using the "message" setting is historic, and
1042 its use is now deprecated. The new add_header modifier should be used instead.
1045 where ACL_WHERE_xxxx indicating which ACL this is
1046 user_message message for adding to headers
1047 log_message message for logging, if different
1053 acl_warn(int where, uschar *user_message, uschar *log_message)
1055 if (log_message != NULL && log_message != user_message)
1058 string_item *logged;
1060 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1061 string_printing(log_message));
1063 /* If a sender verification has failed, and the log message is "sender verify
1064 failed", add the failure message. */
1066 if (sender_verified_failed != NULL &&
1067 sender_verified_failed->message != NULL &&
1068 strcmpic(log_message, US"sender verify failed") == 0)
1069 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1071 /* Search previously logged warnings. They are kept in malloc
1072 store so they can be freed at the start of a new message. */
1074 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1075 if (Ustrcmp(logged->text, text) == 0) break;
1079 int length = Ustrlen(text) + 1;
1080 log_write(0, LOG_MAIN, "%s", text);
1081 logged = store_malloc(sizeof(string_item) + length);
1082 logged->text = (uschar *)logged + sizeof(string_item);
1083 memcpy(logged->text, text, length);
1084 logged->next = acl_warn_logged;
1085 acl_warn_logged = logged;
1089 /* If there's no user message, we are done. */
1091 if (user_message == NULL) return;
1093 /* If this isn't a message ACL, we can't do anything with a user message.
1096 if (where > ACL_WHERE_NOTSMTP)
1098 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1099 "found in a non-message (%s) ACL: cannot specify header lines here: "
1100 "message ignored", acl_wherenames[where]);
1104 /* The code for setting up header lines is now abstracted into a separate
1105 function so that it can be used for the add_header modifier as well. */
1107 setup_header(user_message);
1112 /*************************************************
1113 * Verify and check reverse DNS *
1114 *************************************************/
1116 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1117 address if this has not yet been done. The host_name_lookup() function checks
1118 that one of these names resolves to an address list that contains the client IP
1119 address, so we don't actually have to do the check here.
1122 user_msgptr pointer for user message
1123 log_msgptr pointer for log message
1125 Returns: OK verification condition succeeded
1126 FAIL verification failed
1127 DEFER there was a problem verifying
1131 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1135 user_msgptr = user_msgptr; /* stop compiler warning */
1137 /* Previous success */
1139 if (sender_host_name != NULL) return OK;
1141 /* Previous failure */
1143 if (host_lookup_failed)
1145 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1149 /* Need to do a lookup */
1152 debug_printf("looking up host name to force name/address consistency check\n");
1154 if ((rc = host_name_lookup()) != OK)
1156 *log_msgptr = (rc == DEFER)?
1157 US"host lookup deferred for reverse lookup check"
1159 string_sprintf("host lookup failed for reverse lookup check%s",
1161 return rc; /* DEFER or FAIL */
1164 host_build_sender_fullhost();
1170 /*************************************************
1171 * Check client IP address matches CSA target *
1172 *************************************************/
1174 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1175 response for address records belonging to the CSA target hostname. The section
1176 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1177 If one of the addresses matches the client's IP address, then the client is
1178 authorized by CSA. If there are target IP addresses but none of them match
1179 then the client is using an unauthorized IP address. If there are no target IP
1180 addresses then the client cannot be using an authorized IP address. (This is
1181 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1184 dnsa the DNS answer block
1185 dnss a DNS scan block for us to use
1186 reset option specifing what portion to scan, as described above
1187 target the target hostname to use for matching RR names
1189 Returns: CSA_OK successfully authorized
1190 CSA_FAIL_MISMATCH addresses found but none matched
1191 CSA_FAIL_NOADDR no target addresses found
1195 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1201 BOOL target_found = FALSE;
1203 for (rr = dns_next_rr(dnsa, dnss, reset);
1205 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1207 /* Check this is an address RR for the target hostname. */
1211 && rr->type != T_AAAA
1218 if (strcmpic(target, rr->name) != 0) continue;
1220 target_found = TRUE;
1222 /* Turn the target address RR into a list of textual IP addresses and scan
1223 the list. There may be more than one if it is an A6 RR. */
1225 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1227 /* If the client IP address matches the target IP address, it's good! */
1229 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1231 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1235 /* If we found some target addresses but none of them matched, the client is
1236 using an unauthorized IP address, otherwise the target has no authorized IP
1239 if (target_found) return CSA_FAIL_MISMATCH;
1240 else return CSA_FAIL_NOADDR;
1245 /*************************************************
1246 * Verify Client SMTP Authorization *
1247 *************************************************/
1249 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1250 to find the CSA SRV record corresponding to the domain argument, or
1251 $sender_helo_name if no argument is provided. It then checks that the
1252 client is authorized, and that its IP address corresponds to the SRV
1253 target's address by calling acl_verify_csa_address() above. The address
1254 should have been returned in the DNS response's ADDITIONAL section, but if
1255 not we perform another DNS lookup to get it.
1258 domain pointer to optional parameter following verify = csa
1260 Returns: CSA_UNKNOWN no valid CSA record found
1261 CSA_OK successfully authorized
1262 CSA_FAIL_* client is definitely not authorized
1263 CSA_DEFER_* there was a DNS problem
1267 acl_verify_csa(uschar *domain)
1271 int priority, weight, port;
1278 /* Work out the domain we are using for the CSA lookup. The default is the
1279 client's HELO domain. If the client has not said HELO, use its IP address
1280 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1282 while (isspace(*domain) && *domain != '\0') ++domain;
1283 if (*domain == '\0') domain = sender_helo_name;
1284 if (domain == NULL) domain = sender_host_address;
1285 if (sender_host_address == NULL) return CSA_UNKNOWN;
1287 /* If we have an address literal, strip off the framing ready for turning it
1288 into a domain. The framing consists of matched square brackets possibly
1289 containing a keyword and a colon before the actual IP address. */
1291 if (domain[0] == '[')
1293 uschar *start = Ustrchr(domain, ':');
1294 if (start == NULL) start = domain;
1295 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1298 /* Turn domains that look like bare IP addresses into domains in the reverse
1299 DNS. This code also deals with address literals and $sender_host_address. It's
1300 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1301 address literals, but it's probably the most friendly thing to do. This is an
1302 extension to CSA, so we allow it to be turned off for proper conformance. */
1304 if (string_is_ip_address(domain, NULL) != 0)
1306 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1307 dns_build_reverse(domain, target);
1311 /* Find out if we've already done the CSA check for this domain. If we have,
1312 return the same result again. Otherwise build a new cached result structure
1313 for this domain. The name is filled in now, and the value is filled in when
1314 we return from this function. */
1316 t = tree_search(csa_cache, domain);
1317 if (t != NULL) return t->data.val;
1319 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1320 Ustrcpy(t->name, domain);
1321 (void)tree_insertnode(&csa_cache, t);
1323 /* Now we are ready to do the actual DNS lookup(s). */
1326 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1328 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1331 return t->data.val = CSA_DEFER_SRV;
1333 /* If we found nothing, the client's authorization is unknown. */
1337 return t->data.val = CSA_UNKNOWN;
1339 /* We got something! Go on to look at the reply in more detail. */
1345 /* Scan the reply for well-formed CSA SRV records. */
1347 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1349 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1351 if (rr->type != T_SRV) continue;
1353 /* Extract the numerical SRV fields (p is incremented) */
1356 GETSHORT(priority, p);
1357 GETSHORT(weight, p);
1361 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1363 /* Check the CSA version number */
1365 if (priority != 1) continue;
1367 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1368 found by dns_special_lookup() is a parent of the one we asked for), we check
1369 the subdomain assertions in the port field. At the moment there's only one
1370 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1371 SRV records of their own. */
1373 if (found != domain)
1376 return t->data.val = CSA_FAIL_EXPLICIT;
1378 return t->data.val = CSA_UNKNOWN;
1381 /* This CSA SRV record refers directly to our domain, so we check the value
1382 in the weight field to work out the domain's authorization. 0 and 1 are
1383 unauthorized; 3 means the client is authorized but we can't check the IP
1384 address in order to authenticate it, so we treat it as unknown; values
1385 greater than 3 are undefined. */
1387 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1389 if (weight > 2) continue;
1391 /* Weight == 2, which means the domain is authorized. We must check that the
1392 client's IP address is listed as one of the SRV target addresses. Save the
1393 target hostname then break to scan the additional data for its addresses. */
1395 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1396 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1398 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1403 /* If we didn't break the loop then no appropriate records were found. */
1405 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1407 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1408 A target of "." indicates there are no valid addresses, so the client cannot
1409 be authorized. (This is an odd configuration because weight=2 target=. is
1410 equivalent to weight=1, but we check for it in order to keep load off the
1411 root name servers.) Note that dn_expand() turns "." into "". */
1413 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1415 /* Scan the additional section of the CSA SRV reply for addresses belonging
1416 to the target. If the name server didn't return any additional data (e.g.
1417 because it does not fully support SRV records), we need to do another lookup
1418 to obtain the target addresses; otherwise we have a definitive result. */
1420 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1421 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1423 /* The DNS lookup type corresponds to the IP version used by the client. */
1426 if (Ustrchr(sender_host_address, ':') != NULL)
1429 #endif /* HAVE_IPV6 */
1433 #if HAVE_IPV6 && defined(SUPPORT_A6)
1437 switch (dns_lookup(&dnsa, target, type, NULL))
1439 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1442 return t->data.val = CSA_DEFER_ADDR;
1444 /* If the query succeeded, scan the addresses and return the result. */
1447 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1448 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1449 /* else fall through */
1451 /* If the target has no IP addresses, the client cannot have an authorized
1452 IP address. However, if the target site uses A6 records (not AAAA records)
1453 we have to do yet another lookup in order to check them. */
1458 #if HAVE_IPV6 && defined(SUPPORT_A6)
1459 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1462 return t->data.val = CSA_FAIL_NOADDR;
1468 /*************************************************
1469 * Handle verification (address & other) *
1470 *************************************************/
1472 /* This function implements the "verify" condition. It is called when
1473 encountered in any ACL, because some tests are almost always permitted. Some
1474 just don't make sense, and always fail (for example, an attempt to test a host
1475 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1478 where where called from
1479 addr the recipient address that the ACL is handling, or NULL
1480 arg the argument of "verify"
1481 user_msgptr pointer for user message
1482 log_msgptr pointer for log message
1483 basic_errno where to put verify errno
1485 Returns: OK verification condition succeeded
1486 FAIL verification failed
1487 DEFER there was a problem verifying
1492 acl_verify(int where, address_item *addr, uschar *arg,
1493 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1497 int callout_overall = -1;
1498 int callout_connect = -1;
1499 int verify_options = 0;
1501 BOOL verify_header_sender = FALSE;
1502 BOOL defer_ok = FALSE;
1503 BOOL callout_defer_ok = FALSE;
1504 BOOL no_details = FALSE;
1505 BOOL success_on_redirect = FALSE;
1506 address_item *sender_vaddr = NULL;
1507 uschar *verify_sender_address = NULL;
1508 uschar *pm_mailfrom = NULL;
1509 uschar *se_mailfrom = NULL;
1511 /* Some of the verify items have slash-separated options; some do not. Diagnose
1512 an error if options are given for items that don't expect them. This code has
1513 now got very message. Refactoring to use a table would be a good idea one day.
1516 uschar *slash = Ustrchr(arg, '/');
1518 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1520 if (ss == NULL) goto BAD_VERIFY;
1522 /* Handle name/address consistency verification in a separate function. */
1524 if (strcmpic(ss, US"reverse_host_lookup") == 0)
1526 if (slash != NULL) goto NO_OPTIONS;
1527 if (sender_host_address == NULL) return OK;
1528 return acl_verify_reverse(user_msgptr, log_msgptr);
1531 /* TLS certificate verification is done at STARTTLS time; here we just
1532 test whether it was successful or not. (This is for optional verification; for
1533 mandatory verification, the connection doesn't last this long.) */
1535 if (strcmpic(ss, US"certificate") == 0)
1537 if (slash != NULL) goto NO_OPTIONS;
1538 if (tls_certificate_verified) return OK;
1539 *user_msgptr = US"no verified certificate";
1543 /* We can test the result of optional HELO verification that might have
1544 occurred earlier. If not, we can attempt the verification now. */
1546 if (strcmpic(ss, US"helo") == 0)
1548 if (slash != NULL) goto NO_OPTIONS;
1549 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1550 return helo_verified? OK : FAIL;
1553 /* Do Client SMTP Authorization checks in a separate function, and turn the
1554 result code into user-friendly strings. */
1556 if (strcmpic(ss, US"csa") == 0)
1558 rc = acl_verify_csa(list);
1559 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1560 csa_reason_string[rc]);
1561 csa_status = csa_status_string[rc];
1562 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1563 return csa_return_code[rc];
1566 /* Check that all relevant header lines have the correct syntax. If there is
1567 a syntax error, we return details of the error to the sender if configured to
1568 send out full details. (But a "message" setting on the ACL can override, as
1571 if (strcmpic(ss, US"header_syntax") == 0)
1573 if (slash != NULL) goto NO_OPTIONS;
1574 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1575 rc = verify_check_headers(log_msgptr);
1576 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1577 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1581 /* Check that no recipient of this message is "blind", that is, every envelope
1582 recipient must be mentioned in either To: or Cc:. */
1584 if (strcmpic(ss, US"not_blind") == 0)
1586 if (slash != NULL) goto NO_OPTIONS;
1587 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1588 rc = verify_check_notblind();
1591 *log_msgptr = string_sprintf("bcc recipient detected");
1592 if (smtp_return_error_details)
1593 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1598 /* The remaining verification tests check recipient and sender addresses,
1599 either from the envelope or from the header. There are a number of
1600 slash-separated options that are common to all of them. */
1603 /* Check that there is at least one verifiable sender address in the relevant
1604 header lines. This can be followed by callout and defer options, just like
1605 sender and recipient. */
1607 if (strcmpic(ss, US"header_sender") == 0)
1609 if (where != ACL_WHERE_DATA && where != ACL_WHERE_NOTSMTP) goto WRONG_ACL;
1610 verify_header_sender = TRUE;
1613 /* Otherwise, first item in verify argument must be "sender" or "recipient".
1614 In the case of a sender, this can optionally be followed by an address to use
1615 in place of the actual sender (rare special-case requirement). */
1617 else if (strncmpic(ss, US"sender", 6) == 0)
1620 if (where > ACL_WHERE_NOTSMTP)
1622 *log_msgptr = string_sprintf("cannot verify sender in ACL for %s "
1623 "(only possible for MAIL, RCPT, PREDATA, or DATA)",
1624 acl_wherenames[where]);
1628 verify_sender_address = sender_address;
1631 while (isspace(*s)) s++;
1632 if (*s++ != '=') goto BAD_VERIFY;
1633 while (isspace(*s)) s++;
1634 verify_sender_address = string_copy(s);
1639 if (strcmpic(ss, US"recipient") != 0) goto BAD_VERIFY;
1642 *log_msgptr = string_sprintf("cannot verify recipient in ACL for %s "
1643 "(only possible for RCPT)", acl_wherenames[where]);
1648 /* Remaining items are optional; they apply to sender and recipient
1649 verification, including "header sender" verification. */
1651 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1654 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1655 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1656 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1658 /* These two old options are left for backwards compatibility */
1660 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1662 callout_defer_ok = TRUE;
1663 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1666 else if (strcmpic(ss, US"check_postmaster") == 0)
1669 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1672 /* The callout option has a number of sub-options, comma separated */
1674 else if (strncmpic(ss, US"callout", 7) == 0)
1676 callout = CALLOUT_TIMEOUT_DEFAULT;
1680 while (isspace(*ss)) ss++;
1686 while (isspace(*ss)) ss++;
1688 /* This callout option handling code has become a mess as new options
1689 have been added in an ad hoc manner. It should be tidied up into some
1690 kind of table-driven thing. */
1692 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1695 if (strcmpic(opt, US"defer_ok") == 0) callout_defer_ok = TRUE;
1696 else if (strcmpic(opt, US"no_cache") == 0)
1697 verify_options |= vopt_callout_no_cache;
1698 else if (strcmpic(opt, US"random") == 0)
1699 verify_options |= vopt_callout_random;
1700 else if (strcmpic(opt, US"use_sender") == 0)
1701 verify_options |= vopt_callout_recipsender;
1702 else if (strcmpic(opt, US"use_postmaster") == 0)
1703 verify_options |= vopt_callout_recippmaster;
1704 else if (strcmpic(opt, US"postmaster") == 0) pm_mailfrom = US"";
1705 else if (strcmpic(opt, US"fullpostmaster") == 0)
1708 verify_options |= vopt_callout_fullpm;
1711 else if (strncmpic(opt, US"mailfrom", 8) == 0)
1713 if (!verify_header_sender)
1715 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1716 "callout option only for verify=header_sender (detected in ACL "
1717 "condition \"%s\")", arg);
1721 while (isspace(*opt)) opt++;
1724 *log_msgptr = string_sprintf("'=' expected after "
1725 "\"mailfrom\" in ACL condition \"%s\"", arg);
1728 while (isspace(*opt)) opt++;
1729 se_mailfrom = string_copy(opt);
1732 else if (strncmpic(opt, US"postmaster_mailfrom", 19) == 0)
1735 while (isspace(*opt)) opt++;
1738 *log_msgptr = string_sprintf("'=' expected after "
1739 "\"postmaster_mailfrom\" in ACL condition \"%s\"", arg);
1742 while (isspace(*opt)) opt++;
1743 pm_mailfrom = string_copy(opt);
1746 else if (strncmpic(opt, US"maxwait", 7) == 0)
1749 while (isspace(*opt)) opt++;
1752 *log_msgptr = string_sprintf("'=' expected after \"maxwait\" in "
1753 "ACL condition \"%s\"", arg);
1756 while (isspace(*opt)) opt++;
1757 callout_overall = readconf_readtime(opt, 0, FALSE);
1758 if (callout_overall < 0)
1760 *log_msgptr = string_sprintf("bad time value in ACL condition "
1761 "\"verify %s\"", arg);
1765 else if (strncmpic(opt, US"connect", 7) == 0)
1768 while (isspace(*opt)) opt++;
1771 *log_msgptr = string_sprintf("'=' expected after "
1772 "\"callout_overaall\" in ACL condition \"%s\"", arg);
1775 while (isspace(*opt)) opt++;
1776 callout_connect = readconf_readtime(opt, 0, FALSE);
1777 if (callout_connect < 0)
1779 *log_msgptr = string_sprintf("bad time value in ACL condition "
1780 "\"verify %s\"", arg);
1784 else /* Plain time is callout connect/command timeout */
1786 callout = readconf_readtime(opt, 0, FALSE);
1789 *log_msgptr = string_sprintf("bad time value in ACL condition "
1790 "\"verify %s\"", arg);
1798 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1799 "ACL condition \"%s\"", arg);
1805 /* Option not recognized */
1809 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1810 "condition \"verify %s\"", ss, arg);
1815 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1816 (vopt_callout_recipsender|vopt_callout_recippmaster))
1818 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1819 "for a recipient callout";
1823 /* Handle sender-in-header verification. Default the user message to the log
1824 message if giving out verification details. */
1826 if (verify_header_sender)
1829 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1830 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1834 *basic_errno = verrno;
1835 if (smtp_return_error_details)
1837 if (*user_msgptr == NULL && *log_msgptr != NULL)
1838 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1839 if (rc == DEFER) acl_temp_details = TRUE;
1844 /* Handle a sender address. The default is to verify *the* sender address, but
1845 optionally a different address can be given, for special requirements. If the
1846 address is empty, we are dealing with a bounce message that has no sender, so
1847 we cannot do any checking. If the real sender address gets rewritten during
1848 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1849 during message reception.
1851 A list of verified "sender" addresses is kept to try to avoid doing to much
1852 work repetitively when there are multiple recipients in a message and they all
1853 require sender verification. However, when callouts are involved, it gets too
1854 complicated because different recipients may require different callout options.
1855 Therefore, we always do a full sender verify when any kind of callout is
1856 specified. Caching elsewhere, for instance in the DNS resolver and in the
1857 callout handling, should ensure that this is not terribly inefficient. */
1859 else if (verify_sender_address != NULL)
1861 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1864 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1865 "sender verify callout";
1869 sender_vaddr = verify_checked_sender(verify_sender_address);
1870 if (sender_vaddr != NULL && /* Previously checked */
1871 callout <= 0) /* No callout needed this time */
1873 /* If the "routed" flag is set, it means that routing worked before, so
1874 this check can give OK (the saved return code value, if set, belongs to a
1875 callout that was done previously). If the "routed" flag is not set, routing
1876 must have failed, so we use the saved return code. */
1878 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1880 rc = sender_vaddr->special_action;
1881 *basic_errno = sender_vaddr->basic_errno;
1883 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1886 /* Do a new verification, and cache the result. The cache is used to avoid
1887 verifying the sender multiple times for multiple RCPTs when callouts are not
1888 specified (see comments above).
1890 The cache is also used on failure to give details in response to the first
1891 RCPT that gets bounced for this reason. However, this can be suppressed by
1892 the no_details option, which sets the flag that says "this detail has already
1893 been sent". The cache normally contains just one address, but there may be
1894 more in esoteric circumstances. */
1899 uschar *save_address_data = deliver_address_data;
1901 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1902 if (no_details) setflag(sender_vaddr, af_sverify_told);
1903 if (verify_sender_address[0] != 0)
1905 /* If this is the real sender address, save the unrewritten version
1906 for use later in receive. Otherwise, set a flag so that rewriting the
1907 sender in verify_address() does not update sender_address. */
1909 if (verify_sender_address == sender_address)
1910 sender_address_unrewritten = sender_address;
1912 verify_options |= vopt_fake_sender;
1914 if (success_on_redirect)
1915 verify_options |= vopt_success_on_redirect;
1917 /* The recipient, qualify, and expn options are never set in
1920 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1921 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1923 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1927 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1929 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1930 verify_sender_address, sender_vaddr->address);
1934 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1935 verify_sender_address);
1938 else *basic_errno = sender_vaddr->basic_errno;
1940 else rc = OK; /* Null sender */
1942 /* Cache the result code */
1944 if (routed) setflag(sender_vaddr, af_verify_routed);
1945 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1946 sender_vaddr->special_action = rc;
1947 sender_vaddr->next = sender_verified_list;
1948 sender_verified_list = sender_vaddr;
1950 /* Restore the recipient address data, which might have been clobbered by
1951 the sender verification. */
1953 deliver_address_data = save_address_data;
1956 /* Put the sender address_data value into $sender_address_data */
1958 sender_address_data = sender_vaddr->p.address_data;
1961 /* A recipient address just gets a straightforward verify; again we must handle
1962 the DEFER overrides. */
1968 if (success_on_redirect)
1969 verify_options |= vopt_success_on_redirect;
1971 /* We must use a copy of the address for verification, because it might
1975 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1976 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1977 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1979 *basic_errno = addr2.basic_errno;
1980 *log_msgptr = addr2.message;
1981 *user_msgptr = (addr2.user_message != NULL)?
1982 addr2.user_message : addr2.message;
1984 /* Allow details for temporary error if the address is so flagged. */
1985 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
1987 /* Make $address_data visible */
1988 deliver_address_data = addr2.p.address_data;
1991 /* We have a result from the relevant test. Handle defer overrides first. */
1993 if (rc == DEFER && (defer_ok ||
1994 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1996 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1997 defer_ok? "defer_ok" : "callout_defer_ok");
2001 /* If we've failed a sender, set up a recipient message, and point
2002 sender_verified_failed to the address item that actually failed. */
2004 if (rc != OK && verify_sender_address != NULL)
2008 *log_msgptr = *user_msgptr = US"Sender verify failed";
2010 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2012 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2016 *log_msgptr = US"Could not complete sender verify callout";
2017 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2021 sender_verified_failed = sender_vaddr;
2024 /* Verifying an address messes up the values of $domain and $local_part,
2025 so reset them before returning if this is a RCPT ACL. */
2029 deliver_domain = addr->domain;
2030 deliver_localpart = addr->local_part;
2034 /* Syntax errors in the verify argument come here. */
2037 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2038 "\"helo\", \"header_syntax\", \"header_sender\" or "
2039 "\"reverse_host_lookup\" at start of ACL condition "
2040 "\"verify %s\"", arg);
2043 /* Options supplied when not allowed come here */
2046 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
2047 "(this verify item has no options)", arg);
2050 /* Calls in the wrong ACL come here */
2053 *log_msgptr = string_sprintf("cannot check header contents in ACL for %s "
2054 "(only possible in ACL for DATA)", acl_wherenames[where]);
2061 /*************************************************
2062 * Check argument for control= modifier *
2063 *************************************************/
2065 /* Called from acl_check_condition() below
2068 arg the argument string for control=
2069 pptr set to point to the terminating character
2070 where which ACL we are in
2071 log_msgptr for error messages
2073 Returns: CONTROL_xxx value
2077 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
2082 for (d = controls_list;
2083 d < controls_list + sizeof(controls_list)/sizeof(control_def);
2086 len = Ustrlen(d->name);
2087 if (Ustrncmp(d->name, arg, len) == 0) break;
2090 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
2091 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
2093 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2094 return CONTROL_ERROR;
2103 /*************************************************
2104 * Handle rate limiting *
2105 *************************************************/
2107 /* Called by acl_check_condition() below to calculate the result
2108 of the ACL ratelimit condition.
2110 Note that the return value might be slightly unexpected: if the
2111 sender's rate is above the limit then the result is OK. This is
2112 similar to the dnslists condition, and is so that you can write
2113 ACL clauses like: defer ratelimit = 15 / 1h
2116 arg the option string for ratelimit=
2117 where ACL_WHERE_xxxx indicating which ACL this is
2118 log_msgptr for error messages
2120 Returns: OK - Sender's rate is above limit
2121 FAIL - Sender's rate is below limit
2122 DEFER - Problem opening ratelimit database
2123 ERROR - Syntax error in options.
2127 acl_ratelimit(uschar *arg, int where, uschar **log_msgptr)
2129 double limit, period;
2133 BOOL leaky = FALSE, strict = FALSE, noupdate = FALSE;
2134 BOOL per_byte = FALSE, per_cmd = FALSE, per_conn = FALSE, per_mail = FALSE;
2136 tree_node **anchor, *t;
2137 open_db dbblock, *dbm;
2138 dbdata_ratelimit *dbd;
2141 /* Parse the first two options and record their values in expansion
2142 variables. These variables allow the configuration to have informative
2143 error messages based on rate limits obtained from a table lookup. */
2145 /* First is the maximum number of messages per period and maximum burst
2146 size, which must be greater than or equal to zero. Zero is useful for
2147 rate measurement as opposed to rate limiting. */
2149 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2150 if (sender_rate_limit == NULL)
2154 limit = Ustrtod(sender_rate_limit, &ss);
2155 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2156 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2157 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2159 if (limit < 0.0 || *ss != 0)
2161 *log_msgptr = string_sprintf("syntax error in argument for "
2162 "\"ratelimit\" condition: \"%s\" is not a positive number",
2167 /* Second is the rate measurement period and exponential smoothing time
2168 constant. This must be strictly greater than zero, because zero leads to
2169 run-time division errors. */
2171 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2172 if (sender_rate_period == NULL) period = -1.0;
2173 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2176 *log_msgptr = string_sprintf("syntax error in argument for "
2177 "\"ratelimit\" condition: \"%s\" is not a time value",
2178 sender_rate_period);
2182 /* Parse the other options. Should we check if the per_* options are being
2183 used in ACLs where they don't make sense, e.g. per_mail in the connect ACL? */
2185 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2188 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2189 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2190 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2191 else if (strcmpic(ss, US"per_byte") == 0) per_byte = TRUE;
2192 else if (strcmpic(ss, US"per_cmd") == 0) per_cmd = TRUE;
2193 else if (strcmpic(ss, US"per_rcpt") == 0) per_cmd = TRUE; /* alias */
2194 else if (strcmpic(ss, US"per_conn") == 0) per_conn = TRUE;
2195 else if (strcmpic(ss, US"per_mail") == 0) per_mail = TRUE;
2196 else key = string_sprintf("%s", ss);
2199 if (leaky + strict > 1 || per_byte + per_cmd + per_conn + per_mail > 1)
2201 *log_msgptr = US"conflicting options for \"ratelimit\" condition";
2205 /* Default option values */
2207 if (!strict) leaky = TRUE;
2208 if (!per_byte && !per_cmd && !per_conn) per_mail = TRUE;
2210 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2211 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2212 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2213 are added to the key because they alter the meaning of the stored data. */
2216 key = (sender_host_address == NULL)? US"" : sender_host_address;
2218 key = string_sprintf("%s/%s/%s/%s",
2220 per_byte? US"per_byte" :
2221 per_cmd? US"per_cmd" :
2222 per_mail? US"per_mail" : US"per_conn",
2223 strict? US"strict" : US"leaky",
2226 HDEBUG(D_acl) debug_printf("ratelimit condition limit=%.0f period=%.0f key=%s\n",
2227 limit, period, key);
2229 /* See if we have already computed the rate by looking in the relevant tree.
2230 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2231 pool so that they survive across resets. */
2234 old_pool = store_pool;
2238 anchor = &ratelimiters_conn;
2239 store_pool = POOL_PERM;
2241 else if (per_mail || per_byte)
2242 anchor = &ratelimiters_mail;
2244 anchor = &ratelimiters_cmd;
2246 if (anchor != NULL && (t = tree_search(*anchor, key)) != NULL)
2249 /* The following few lines duplicate some of the code below. */
2250 rc = (dbd->rate < limit)? FAIL : OK;
2251 store_pool = old_pool;
2252 sender_rate = string_sprintf("%.1f", dbd->rate);
2254 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2258 /* We aren't using a pre-computed rate, so get a previously recorded
2259 rate from the database, update it, and write it back when required. If there's
2260 no previous rate for this key, create one. */
2262 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2265 store_pool = old_pool;
2267 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2268 *log_msgptr = US"ratelimit database not available";
2271 dbd = dbfn_read(dbm, key);
2273 gettimeofday(&tv, NULL);
2277 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's data\n");
2278 dbd = store_get(sizeof(dbdata_ratelimit));
2279 dbd->time_stamp = tv.tv_sec;
2280 dbd->time_usec = tv.tv_usec;
2285 /* The smoothed rate is computed using an exponentially weighted moving
2286 average adjusted for variable sampling intervals. The standard EWMA for
2287 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2288 where f() is the measured value and f'() is the smoothed value.
2290 Old data decays out of the smoothed value exponentially, such that data n
2291 samples old is multiplied by a^n. The exponential decay time constant p
2292 is defined such that data p samples old is multiplied by 1/e, which means
2293 that a = exp(-1/p). We can maintain the same time constant for a variable
2294 sampling interval i by using a = exp(-i/p).
2296 The rate we are measuring is messages per period, suitable for directly
2297 comparing with the limit. The average rate between now and the previous
2298 message is period / interval, which we feed into the EWMA as the sample.
2300 It turns out that the number of messages required for the smoothed rate
2301 to reach the limit when they are sent in a burst is equal to the limit.
2302 This can be seen by analysing the value of the smoothed rate after N
2303 messages sent at even intervals. Let k = (1 - a) * p/i
2305 rate_1 = (1 - a) * p/i + a * rate_0
2307 rate_2 = k + a * rate_1
2308 = k + a * k + a^2 * rate_0
2309 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2310 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2311 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2312 = rate_0 * a^N + p/i * (1 - a^N)
2314 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2316 rate_N = p/i + (rate_0 - p/i) * a^N
2317 a^N = (rate_N - p/i) / (rate_0 - p/i)
2318 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2319 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2321 Numerical analysis of the above equation, setting the computed rate to
2322 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2323 rates, p/i, the number of messages N = limit. So limit serves as both the
2324 maximum rate measured in messages per period, and the maximum number of
2325 messages that can be sent in a fast burst. */
2327 double this_time = (double)tv.tv_sec
2328 + (double)tv.tv_usec / 1000000.0;
2329 double prev_time = (double)dbd->time_stamp
2330 + (double)dbd->time_usec / 1000000.0;
2332 /* We must avoid division by zero, and deal gracefully with the clock going
2333 backwards. If we blunder ahead when time is in reverse then the computed
2334 rate will be bogus. To be safe we clamp interval to a very small number. */
2336 double interval = this_time - prev_time <= 0.0 ? 1e-9
2337 : this_time - prev_time;
2339 double i_over_p = interval / period;
2340 double a = exp(-i_over_p);
2342 dbd->time_stamp = tv.tv_sec;
2343 dbd->time_usec = tv.tv_usec;
2345 /* If we are measuring the rate in bytes per period, multiply the
2346 measured rate by the message size. If we don't know the message size
2347 then it's safe to just use a value of zero and let the recorded rate
2348 decay as if nothing happened. */
2351 dbd->rate = (message_size < 0 ? 0.0 : (double)message_size)
2352 * (1 - a) / i_over_p + a * dbd->rate;
2353 else if (per_cmd && where == ACL_WHERE_NOTSMTP)
2354 dbd->rate = (double)recipients_count
2355 * (1 - a) / i_over_p + a * dbd->rate;
2357 dbd->rate = (1 - a) / i_over_p + a * dbd->rate;
2360 /* Clients sending at the limit are considered to be over the limit. This
2361 matters for edge cases such the first message sent by a client (which gets
2362 the initial rate of 0.0) when the rate limit is zero (i.e. the client should
2363 be completely blocked). */
2365 rc = (dbd->rate < limit)? FAIL : OK;
2367 /* Update the state if the rate is low or if we are being strict. If we
2368 are in leaky mode and the sender's rate is too high, we do not update
2369 the recorded rate in order to avoid an over-aggressive sender's retry
2370 rate preventing them from getting any email through. If noupdate is set,
2371 do not do any updates. */
2373 if ((rc == FAIL || !leaky) && !noupdate)
2375 dbfn_write(dbm, key, dbd, sizeof(dbdata_ratelimit));
2376 HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
2380 HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
2381 noupdate? "noupdate set" : "over the limit, but leaky");
2386 /* Store the result in the tree for future reference, if necessary. */
2388 if (anchor != NULL && !noupdate)
2390 t = store_get(sizeof(tree_node) + Ustrlen(key));
2392 Ustrcpy(t->name, key);
2393 (void)tree_insertnode(anchor, t);
2396 /* We create the formatted version of the sender's rate very late in
2397 order to ensure that it is done using the correct storage pool. */
2399 store_pool = old_pool;
2400 sender_rate = string_sprintf("%.1f", dbd->rate);
2403 debug_printf("ratelimit computed rate %s\n", sender_rate);
2410 /*************************************************
2411 * Handle conditions/modifiers on an ACL item *
2412 *************************************************/
2414 /* Called from acl_check() below.
2418 cb ACL condition block - if NULL, result is OK
2419 where where called from
2420 addr the address being checked for RCPT, or NULL
2421 level the nesting level
2422 epp pointer to pass back TRUE if "endpass" encountered
2423 (applies only to "accept" and "discard")
2424 user_msgptr user message pointer
2425 log_msgptr log message pointer
2426 basic_errno pointer to where to put verify error
2428 Returns: OK - all conditions are met
2429 DISCARD - an "acl" condition returned DISCARD - only allowed
2430 for "accept" or "discard" verbs
2431 FAIL - at least one condition fails
2432 FAIL_DROP - an "acl" condition returned FAIL_DROP
2433 DEFER - can't tell at the moment (typically, lookup defer,
2434 but can be temporary callout problem)
2435 ERROR - ERROR from nested ACL or expansion failure or other
2440 acl_check_condition(int verb, acl_condition_block *cb, int where,
2441 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2442 uschar **log_msgptr, int *basic_errno)
2444 uschar *user_message = NULL;
2445 uschar *log_message = NULL;
2448 #ifdef WITH_CONTENT_SCAN
2452 for (; cb != NULL; cb = cb->next)
2457 /* The message and log_message items set up messages to be used in
2458 case of rejection. They are expanded later. */
2460 if (cb->type == ACLC_MESSAGE)
2462 user_message = cb->arg;
2466 if (cb->type == ACLC_LOG_MESSAGE)
2468 log_message = cb->arg;
2472 /* The endpass "condition" just sets a flag to show it occurred. This is
2473 checked at compile time to be on an "accept" or "discard" item. */
2475 if (cb->type == ACLC_ENDPASS)
2481 /* For other conditions and modifiers, the argument is expanded now for some
2482 of them, but not for all, because expansion happens down in some lower level
2483 checking functions in some cases. */
2485 if (cond_expand_at_top[cb->type])
2487 arg = expand_string(cb->arg);
2490 if (expand_string_forcedfail) continue;
2491 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2492 cb->arg, expand_string_message);
2493 return search_find_defer? DEFER : ERROR;
2498 /* Show condition, and expanded condition if it's different */
2503 debug_printf("check %s%s %n",
2504 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2505 conditions[cb->type], &lhswidth);
2507 if (cb->type == ACLC_SET)
2509 debug_printf("acl_%s ", cb->u.varname);
2510 lhswidth += 5 + Ustrlen(cb->u.varname);
2513 debug_printf("= %s\n", cb->arg);
2516 debug_printf("%.*s= %s\n", lhswidth,
2520 /* Check that this condition makes sense at this time */
2522 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2524 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2525 cond_modifiers[cb->type]? "use" : "test",
2526 conditions[cb->type], acl_wherenames[where]);
2530 /* Run the appropriate test for each condition, or take the appropriate
2531 action for the remaining modifiers. */
2535 case ACLC_ADD_HEADER:
2539 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2543 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2544 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2546 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2547 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2553 case ACLC_AUTHENTICATED:
2554 rc = (sender_host_authenticated == NULL)? FAIL :
2555 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2559 #ifdef EXPERIMENTAL_BRIGHTMAIL
2560 case ACLC_BMI_OPTIN:
2562 int old_pool = store_pool;
2563 store_pool = POOL_PERM;
2564 bmi_current_optin = string_copy(arg);
2565 store_pool = old_pool;
2570 case ACLC_CONDITION:
2571 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2572 rc = (Uatoi(arg) == 0)? FAIL : OK;
2574 rc = (strcmpic(arg, US"no") == 0 ||
2575 strcmpic(arg, US"false") == 0)? FAIL :
2576 (strcmpic(arg, US"yes") == 0 ||
2577 strcmpic(arg, US"true") == 0)? OK : DEFER;
2579 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2582 case ACLC_CONTINUE: /* Always succeeds */
2586 control_type = decode_control(arg, &p, where, log_msgptr);
2588 /* Check if this control makes sense at this time */
2590 if ((control_forbids[control_type] & (1 << where)) != 0)
2592 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2593 controls[control_type], acl_wherenames[where]);
2597 switch(control_type)
2599 case CONTROL_AUTH_UNADVERTISED:
2600 allow_auth_unadvertised = TRUE;
2603 #ifdef EXPERIMENTAL_BRIGHTMAIL
2604 case CONTROL_BMI_RUN:
2609 #ifdef EXPERIMENTAL_DOMAINKEYS
2610 case CONTROL_DK_VERIFY:
2618 case CONTROL_CASEFUL_LOCAL_PART:
2619 deliver_localpart = addr->cc_local_part;
2622 case CONTROL_CASELOWER_LOCAL_PART:
2623 deliver_localpart = addr->lc_local_part;
2626 case CONTROL_ENFORCE_SYNC:
2627 smtp_enforce_sync = TRUE;
2630 case CONTROL_NO_ENFORCE_SYNC:
2631 smtp_enforce_sync = FALSE;
2634 #ifdef WITH_CONTENT_SCAN
2635 case CONTROL_NO_MBOX_UNSPOOL:
2636 no_mbox_unspool = TRUE;
2640 case CONTROL_NO_MULTILINE:
2641 no_multiline_responses = TRUE;
2644 case CONTROL_NO_PIPELINING:
2645 pipelining_enable = FALSE;
2648 case CONTROL_NO_DELAY_FLUSH:
2649 disable_delay_flush = TRUE;
2652 case CONTROL_NO_CALLOUT_FLUSH:
2653 disable_callout_flush = TRUE;
2656 case CONTROL_FAKEDEFER:
2657 case CONTROL_FAKEREJECT:
2658 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2662 while (*pp != 0) pp++;
2663 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2668 /* Explicitly reset to default string */
2669 fake_response_text = US"Your message has been rejected but is being kept for evaluation.\nIf it was a legitimate message, it may still be delivered to the target recipient(s).";
2673 case CONTROL_FREEZE:
2674 deliver_freeze = TRUE;
2675 deliver_frozen_at = time(NULL);
2676 freeze_tell = freeze_tell_config; /* Reset to configured value */
2677 if (Ustrncmp(p, "/no_tell", 8) == 0)
2684 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2689 case CONTROL_QUEUE_ONLY:
2690 queue_only_policy = TRUE;
2693 case CONTROL_SUBMISSION:
2694 originator_name = US"";
2695 submission_mode = TRUE;
2698 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2701 active_local_sender_retain = TRUE;
2702 active_local_from_check = FALSE;
2704 else if (Ustrncmp(p, "/domain=", 8) == 0)
2707 while (*pp != 0 && *pp != '/') pp++;
2708 submission_domain = string_copyn(p+8, pp-p-8);
2711 /* The name= option must be last, because it swallows the rest of
2713 else if (Ustrncmp(p, "/name=", 6) == 0)
2716 while (*pp != 0) pp++;
2717 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2718 big_buffer, big_buffer_size));
2725 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2730 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
2731 suppress_local_fixups = TRUE;
2736 #ifdef WITH_CONTENT_SCAN
2738 rc = mime_decode(&arg);
2744 int delay = readconf_readtime(arg, 0, FALSE);
2747 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
2748 "modifier: \"%s\" is not a time value", arg);
2753 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
2758 debug_printf("delay skipped in -bh checking mode\n");
2761 /* It appears to be impossible to detect that a TCP/IP connection has
2762 gone away without reading from it. This means that we cannot shorten
2763 the delay below if the client goes away, because we cannot discover
2764 that the client has closed its end of the connection. (The connection
2765 is actually in a half-closed state, waiting for the server to close its
2766 end.) It would be nice to be able to detect this state, so that the
2767 Exim process is not held up unnecessarily. However, it seems that we
2768 can't. The poll() function does not do the right thing, and in any case
2769 it is not always available.
2771 NOTE 1: If ever this state of affairs changes, remember that we may be
2772 dealing with stdin/stdout here, in addition to TCP/IP connections.
2773 Also, delays may be specified for non-SMTP input, where smtp_out and
2774 smtp_in will be NULL. Whatever is done must work in all cases.
2776 NOTE 2: The added feature of flushing the output before a delay must
2777 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
2782 if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush();
2783 while (delay > 0) delay = sleep(delay);
2789 #ifdef WITH_OLD_DEMIME
2795 #ifdef EXPERIMENTAL_DOMAINKEYS
2796 case ACLC_DK_DOMAIN_SOURCE:
2797 if (dk_verify_block == NULL) { rc = FAIL; break; };
2798 /* check header source of domain against given string */
2799 switch (dk_verify_block->address_source) {
2800 case DK_EXIM_ADDRESS_FROM_FROM:
2801 rc = match_isinlist(US"from", &arg, 0, NULL,
2802 NULL, MCL_STRING, TRUE, NULL);
2804 case DK_EXIM_ADDRESS_FROM_SENDER:
2805 rc = match_isinlist(US"sender", &arg, 0, NULL,
2806 NULL, MCL_STRING, TRUE, NULL);
2808 case DK_EXIM_ADDRESS_NONE:
2809 rc = match_isinlist(US"none", &arg, 0, NULL,
2810 NULL, MCL_STRING, TRUE, NULL);
2815 case ACLC_DK_POLICY:
2816 if (dk_verify_block == NULL) { rc = FAIL; break; };
2817 /* check policy against given string, default FAIL */
2819 if (dk_verify_block->signsall)
2820 rc = match_isinlist(US"signsall", &arg, 0, NULL,
2821 NULL, MCL_STRING, TRUE, NULL);
2822 if (dk_verify_block->testing)
2823 rc = match_isinlist(US"testing", &arg, 0, NULL,
2824 NULL, MCL_STRING, TRUE, NULL);
2827 case ACLC_DK_SENDER_DOMAINS:
2828 if (dk_verify_block == NULL) { rc = FAIL; break; };
2829 if (dk_verify_block->domain != NULL)
2830 rc = match_isinlist(dk_verify_block->domain, &arg, 0, &domainlist_anchor,
2831 NULL, MCL_DOMAIN, TRUE, NULL);
2835 case ACLC_DK_SENDER_LOCAL_PARTS:
2836 if (dk_verify_block == NULL) { rc = FAIL; break; };
2837 if (dk_verify_block->local_part != NULL)
2838 rc = match_isinlist(dk_verify_block->local_part, &arg, 0, &localpartlist_anchor,
2839 NULL, MCL_LOCALPART, TRUE, NULL);
2843 case ACLC_DK_SENDERS:
2844 if (dk_verify_block == NULL) { rc = FAIL; break; };
2845 if (dk_verify_block->address != NULL)
2846 rc = match_address_list(dk_verify_block->address, TRUE, TRUE, &arg, NULL, -1, 0, NULL);
2850 case ACLC_DK_STATUS:
2851 if (dk_verify_block == NULL) { rc = FAIL; break; };
2852 if (dk_verify_block->result > 0) {
2853 switch(dk_verify_block->result) {
2854 case DK_EXIM_RESULT_BAD_FORMAT:
2855 rc = match_isinlist(US"bad format", &arg, 0, NULL,
2856 NULL, MCL_STRING, TRUE, NULL);
2858 case DK_EXIM_RESULT_NO_KEY:
2859 rc = match_isinlist(US"no key", &arg, 0, NULL,
2860 NULL, MCL_STRING, TRUE, NULL);
2862 case DK_EXIM_RESULT_NO_SIGNATURE:
2863 rc = match_isinlist(US"no signature", &arg, 0, NULL,
2864 NULL, MCL_STRING, TRUE, NULL);
2866 case DK_EXIM_RESULT_REVOKED:
2867 rc = match_isinlist(US"revoked", &arg, 0, NULL,
2868 NULL, MCL_STRING, TRUE, NULL);
2870 case DK_EXIM_RESULT_NON_PARTICIPANT:
2871 rc = match_isinlist(US"non-participant", &arg, 0, NULL,
2872 NULL, MCL_STRING, TRUE, NULL);
2874 case DK_EXIM_RESULT_GOOD:
2875 rc = match_isinlist(US"good", &arg, 0, NULL,
2876 NULL, MCL_STRING, TRUE, NULL);
2878 case DK_EXIM_RESULT_BAD:
2879 rc = match_isinlist(US"bad", &arg, 0, NULL,
2880 NULL, MCL_STRING, TRUE, NULL);
2888 rc = verify_check_dnsbl(&arg);
2892 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
2893 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
2896 /* The value in tls_cipher is the full cipher name, for example,
2897 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
2898 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
2899 what may in practice come out of the SSL library - which at the time of
2900 writing is poorly documented. */
2902 case ACLC_ENCRYPTED:
2903 if (tls_cipher == NULL) rc = FAIL; else
2905 uschar *endcipher = NULL;
2906 uschar *cipher = Ustrchr(tls_cipher, ':');
2907 if (cipher == NULL) cipher = tls_cipher; else
2909 endcipher = Ustrchr(++cipher, ':');
2910 if (endcipher != NULL) *endcipher = 0;
2912 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
2913 if (endcipher != NULL) *endcipher = ':';
2917 /* Use verify_check_this_host() instead of verify_check_host() so that
2918 we can pass over &host_data to catch any looked up data. Once it has been
2919 set, it retains its value so that it's still there if another ACL verb
2920 comes through here and uses the cache. However, we must put it into
2921 permanent store in case it is also expected to be used in a subsequent
2922 message in the same SMTP connection. */
2925 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
2926 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
2927 if (host_data != NULL) host_data = string_copy_malloc(host_data);
2930 case ACLC_LOCAL_PARTS:
2931 rc = match_isinlist(addr->cc_local_part, &arg, 0,
2932 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
2933 &deliver_localpart_data);
2936 case ACLC_LOG_REJECT_TARGET:
2942 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
2945 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
2946 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
2947 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
2950 logbits |= LOG_MAIN|LOG_REJECT;
2951 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
2952 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
2955 log_reject_target = logbits;
2968 if (Ustrncmp(s, "main", 4) == 0)
2969 { logbits |= LOG_MAIN; s += 4; }
2970 else if (Ustrncmp(s, "panic", 5) == 0)
2971 { logbits |= LOG_PANIC; s += 5; }
2972 else if (Ustrncmp(s, "reject", 6) == 0)
2973 { logbits |= LOG_REJECT; s += 6; }
2976 logbits = LOG_MAIN|LOG_PANIC;
2977 s = string_sprintf(":unknown log name in \"%s\" in "
2978 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
2984 while (isspace(*s)) s++;
2987 if (logbits == 0) logbits = LOG_MAIN;
2988 log_write(0, logbits, "%s", string_printing(s));
2992 #ifdef WITH_CONTENT_SCAN
2995 /* Separate the regular expression and any optional parameters. */
2996 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2997 /* Run the malware backend. */
2999 /* Modify return code based upon the existance of options. */
3000 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3002 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3004 /* FAIL so that the message is passed to the next ACL */
3011 case ACLC_MIME_REGEX:
3012 rc = mime_regex(&arg);
3016 case ACLC_RATELIMIT:
3017 rc = acl_ratelimit(arg, where, log_msgptr);
3020 case ACLC_RECIPIENTS:
3021 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3025 #ifdef WITH_CONTENT_SCAN
3031 case ACLC_SENDER_DOMAINS:
3034 sdomain = Ustrrchr(sender_address, '@');
3035 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
3036 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3037 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3042 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
3043 sender_address_cache, -1, 0, &sender_data);
3046 /* Connection variables must persist forever */
3050 int old_pool = store_pool;
3051 if (cb->u.varname[0] == 'c') store_pool = POOL_PERM;
3052 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3053 store_pool = old_pool;
3057 #ifdef WITH_CONTENT_SCAN
3060 /* Seperate the regular expression and any optional parameters. */
3061 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3062 /* Run the spam backend. */
3064 /* Modify return code based upon the existance of options. */
3065 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3067 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3069 /* FAIL so that the message is passed to the next ACL */
3077 #ifdef EXPERIMENTAL_SPF
3079 rc = spf_process(&arg, sender_address);
3083 /* If the verb is WARN, discard any user message from verification, because
3084 such messages are SMTP responses, not header additions. The latter come
3085 only from explicit "message" modifiers. However, put the user message into
3086 $acl_verify_message so it can be used in subsequent conditions or modifiers
3087 (until something changes it). */
3090 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3091 acl_verify_message = *user_msgptr;
3092 if (verb == ACL_WARN) *user_msgptr = NULL;
3096 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3097 "condition %d", cb->type);
3101 /* If a condition was negated, invert OK/FAIL. */
3103 if (!cond_modifiers[cb->type] && cb->u.negated)
3105 if (rc == OK) rc = FAIL;
3106 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3109 if (rc != OK) break; /* Conditions loop */
3113 /* If the result is the one for which "message" and/or "log_message" are used,
3114 handle the values of these modifiers. If there isn't a log message set, we make
3115 it the same as the user message.
3117 "message" is a user message that will be included in an SMTP response. Unless
3118 it is empty, it overrides any previously set user message.
3120 "log_message" is a non-user message, and it adds to any existing non-user
3121 message that is already set.
3123 Most verbs have but a single return for which the messages are relevant, but
3124 for "discard", it's useful to have the log message both when it succeeds and
3125 when it fails. For "accept", the message is used in the OK case if there is no
3126 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3129 if (*epp && rc == OK) user_message = NULL;
3131 if (((1<<rc) & msgcond[verb]) != 0)
3134 uschar *old_user_msgptr = *user_msgptr;
3135 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3137 /* If the verb is "warn", messages generated by conditions (verification or
3138 nested ACLs) are always discarded. This also happens for acceptance verbs
3139 when they actually do accept. Only messages specified at this level are used.
3140 However, the value of an existing message is available in $acl_verify_message
3141 during expansions. */
3143 if (verb == ACL_WARN ||
3144 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3145 *log_msgptr = *user_msgptr = NULL;
3147 if (user_message != NULL)
3149 acl_verify_message = old_user_msgptr;
3150 expmessage = expand_string(user_message);
3151 if (expmessage == NULL)
3153 if (!expand_string_forcedfail)
3154 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3155 user_message, expand_string_message);
3157 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3160 if (log_message != NULL)
3162 acl_verify_message = old_log_msgptr;
3163 expmessage = expand_string(log_message);
3164 if (expmessage == NULL)
3166 if (!expand_string_forcedfail)
3167 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3168 log_message, expand_string_message);
3170 else if (expmessage[0] != 0)
3172 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3173 string_sprintf("%s: %s", expmessage, *log_msgptr);
3177 /* If no log message, default it to the user message */
3179 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3182 acl_verify_message = NULL;
3190 /*************************************************
3191 * Get line from a literal ACL *
3192 *************************************************/
3194 /* This function is passed to acl_read() in order to extract individual lines
3195 of a literal ACL, which we access via static pointers. We can destroy the
3196 contents because this is called only once (the compiled ACL is remembered).
3198 This code is intended to treat the data in the same way as lines in the main
3199 Exim configuration file. That is:
3201 . Leading spaces are ignored.
3203 . A \ at the end of a line is a continuation - trailing spaces after the \
3204 are permitted (this is because I don't believe in making invisible things
3205 significant). Leading spaces on the continued part of a line are ignored.
3207 . Physical lines starting (significantly) with # are totally ignored, and
3208 may appear within a sequence of backslash-continued lines.
3210 . Blank lines are ignored, but will end a sequence of continuations.
3213 Returns: a pointer to the next line
3217 static uschar *acl_text; /* Current pointer in the text */
3218 static uschar *acl_text_end; /* Points one past the terminating '0' */
3226 /* This loop handles leading blank lines and comments. */
3230 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3231 if (*acl_text == 0) return NULL; /* No more data */
3232 yield = acl_text; /* Potential data line */
3234 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3236 /* If we hit the end before a newline, we have the whole logical line. If
3237 it's a comment, there's no more data to be given. Otherwise, yield it. */
3239 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3241 /* After reaching a newline, end this loop if the physical line does not
3242 start with '#'. If it does, it's a comment, and the loop continues. */
3244 if (*yield != '#') break;
3247 /* This loop handles continuations. We know we have some real data, ending in
3248 newline. See if there is a continuation marker at the end (ignoring trailing
3249 white space). We know that *yield is not white space, so no need to test for
3250 cont > yield in the backwards scanning loop. */
3255 for (cont = acl_text - 1; isspace(*cont); cont--);
3257 /* If no continuation follows, we are done. Mark the end of the line and
3266 /* We have encountered a continuation. Skip over whitespace at the start of
3267 the next line, and indeed the whole of the next line or lines if they are
3272 while (*(++acl_text) == ' ' || *acl_text == '\t');
3273 if (*acl_text != '#') break;
3274 while (*(++acl_text) != 0 && *acl_text != '\n');
3277 /* We have the start of a continuation line. Move all the rest of the data
3278 to join onto the previous line, and then find its end. If the end is not a
3279 newline, we are done. Otherwise loop to look for another continuation. */
3281 memmove(cont, acl_text, acl_text_end - acl_text);
3282 acl_text_end -= acl_text - cont;
3284 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3285 if (*acl_text == 0) return yield;
3288 /* Control does not reach here */
3295 /*************************************************
3296 * Check access using an ACL *
3297 *************************************************/
3299 /* This function is called from address_check. It may recurse via
3300 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3301 passed as a string which is expanded. A forced failure implies no access check
3302 is required. If the result is a single word, it is taken as the name of an ACL
3303 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3304 text, complete with newlines, and parsed as such. In both cases, the ACL check
3305 is then run. This function uses an auxiliary function for acl_read() to call
3306 for reading individual lines of a literal ACL. This is acl_getline(), which
3307 appears immediately above.
3310 where where called from
3311 addr address item when called from RCPT; otherwise NULL
3312 s the input string; NULL is the same as an empty ACL => DENY
3313 level the nesting level
3314 user_msgptr where to put a user error (for SMTP response)
3315 log_msgptr where to put a logging message (not for SMTP response)
3317 Returns: OK access is granted
3318 DISCARD access is apparently granted...
3319 FAIL access is denied
3320 FAIL_DROP access is denied; drop the connection
3321 DEFER can't tell at the moment
3326 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3327 uschar **user_msgptr, uschar **log_msgptr)
3330 acl_block *acl = NULL;
3331 uschar *acl_name = US"inline ACL";
3334 /* Catch configuration loops */
3338 *log_msgptr = US"ACL nested too deep: possible loop";
3344 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3348 /* At top level, we expand the incoming string. At lower levels, it has already
3349 been expanded as part of condition processing. */
3353 ss = expand_string(s);
3356 if (expand_string_forcedfail) return OK;
3357 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3358 expand_string_message);
3364 while (isspace(*ss))ss++;
3366 /* If we can't find a named ACL, the default is to parse it as an inline one.
3367 (Unless it begins with a slash; non-existent files give rise to an error.) */
3371 /* Handle the case of a string that does not contain any spaces. Look for a
3372 named ACL among those read from the configuration, or a previously read file.
3373 It is possible that the pointer to the ACL is NULL if the configuration
3374 contains a name with no data. If not found, and the text begins with '/',
3375 read an ACL from a file, and save it so it can be re-used. */
3377 if (Ustrchr(ss, ' ') == NULL)
3379 tree_node *t = tree_search(acl_anchor, ss);
3382 acl = (acl_block *)(t->data.ptr);
3385 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3388 acl_name = string_sprintf("ACL \"%s\"", ss);
3389 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3392 else if (*ss == '/')
3394 struct stat statbuf;
3395 fd = Uopen(ss, O_RDONLY, 0);
3398 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3403 if (fstat(fd, &statbuf) != 0)
3405 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3410 acl_text = store_get(statbuf.st_size + 1);
3411 acl_text_end = acl_text + statbuf.st_size + 1;
3413 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3415 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3416 ss, strerror(errno));
3419 acl_text[statbuf.st_size] = 0;
3422 acl_name = string_sprintf("ACL \"%s\"", ss);
3423 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3427 /* Parse an ACL that is still in text form. If it came from a file, remember it
3428 in the ACL tree, having read it into the POOL_PERM store pool so that it
3429 persists between multiple messages. */
3433 int old_pool = store_pool;
3434 if (fd >= 0) store_pool = POOL_PERM;
3435 acl = acl_read(acl_getline, log_msgptr);
3436 store_pool = old_pool;
3437 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3440 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3441 Ustrcpy(t->name, ss);
3443 (void)tree_insertnode(&acl_anchor, t);
3447 /* Now we have an ACL to use. It's possible it may be NULL. */
3452 int basic_errno = 0;
3453 BOOL endpass_seen = FALSE;
3455 *log_msgptr = *user_msgptr = NULL;
3456 acl_temp_details = FALSE;
3458 if (where == ACL_WHERE_QUIT &&
3459 acl->verb != ACL_ACCEPT &&
3460 acl->verb != ACL_WARN)
3462 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT ACL",
3467 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3469 /* Clear out any search error message from a previous check before testing
3472 search_error_message = NULL;
3473 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3474 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3476 /* Handle special returns: DEFER causes a return except on a WARN verb;
3477 ERROR always causes a return. */
3482 HDEBUG(D_acl) debug_printf("%s: condition test deferred\n", verbs[acl->verb]);
3483 if (basic_errno != ERRNO_CALLOUTDEFER)
3485 if (search_error_message != NULL && *search_error_message != 0)
3486 *log_msgptr = search_error_message;
3487 if (smtp_return_error_details) acl_temp_details = TRUE;
3491 acl_temp_details = TRUE;
3493 if (acl->verb != ACL_WARN) return DEFER;
3496 default: /* Paranoia */
3498 HDEBUG(D_acl) debug_printf("%s: condition test error\n", verbs[acl->verb]);
3502 HDEBUG(D_acl) debug_printf("%s: condition test succeeded\n",
3507 HDEBUG(D_acl) debug_printf("%s: condition test failed\n", verbs[acl->verb]);
3510 /* DISCARD and DROP can happen only from a nested ACL condition, and
3511 DISCARD can happen only for an "accept" or "discard" verb. */
3514 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\"\n",
3519 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\"\n",
3524 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3525 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3526 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3531 if (cond == OK || cond == DISCARD) return cond;
3534 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3542 acl_temp_details = TRUE;
3548 if (cond == OK) return FAIL;
3552 if (cond == OK || cond == DISCARD) return DISCARD;
3555 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3561 if (cond == OK) return FAIL_DROP;
3565 if (cond != OK) return cond;
3570 acl_warn(where, *user_msgptr, *log_msgptr);
3571 else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
3572 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3573 "condition test deferred%s%s", host_and_ident(TRUE),
3574 (*log_msgptr == NULL)? US"" : US": ",
3575 (*log_msgptr == NULL)? US"" : *log_msgptr);
3576 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3580 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3585 /* Pass to the next ACL item */
3590 /* We have reached the end of the ACL. This is an implicit DENY. */
3592 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3597 /*************************************************
3598 * Check access using an ACL *
3599 *************************************************/
3601 /* This is the external interface for ACL checks. It sets up an address and the
3602 expansions for $domain and $local_part when called after RCPT, then calls
3603 acl_check_internal() to do the actual work.
3606 where ACL_WHERE_xxxx indicating where called from
3607 recipient RCPT address for RCPT check, else NULL
3608 s the input string; NULL is the same as an empty ACL => DENY
3609 user_msgptr where to put a user error (for SMTP response)
3610 log_msgptr where to put a logging message (not for SMTP response)
3612 Returns: OK access is granted by an ACCEPT verb
3613 DISCARD access is granted by a DISCARD verb
3614 FAIL access is denied
3615 FAIL_DROP access is denied; drop the connection
3616 DEFER can't tell at the moment
3621 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
3622 uschar **log_msgptr)
3626 address_item *addr = NULL;
3628 *user_msgptr = *log_msgptr = NULL;
3629 sender_verified_failed = NULL;
3630 ratelimiters_cmd = NULL;
3631 log_reject_target = LOG_MAIN|LOG_REJECT;
3633 if (where == ACL_WHERE_RCPT)
3635 adb = address_defaults;
3637 addr->address = recipient;
3638 if (deliver_split_address(addr) == DEFER)
3640 *log_msgptr = US"defer in percent_hack_domains check";
3643 deliver_domain = addr->domain;
3644 deliver_localpart = addr->local_part;
3647 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3649 deliver_domain = deliver_localpart = deliver_address_data =
3650 sender_address_data = NULL;
3652 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3653 ACL, which is really in the middle of an SMTP command. */
3657 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3659 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3660 "ACL", acl_wherenames[where]);
3666 /* A DROP response is not permitted from MAILAUTH */
3668 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3670 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3671 "ACL", acl_wherenames[where]);
3675 /* Before giving a response, take a look at the length of any user message, and
3676 split it up into multiple lines if possible. */
3678 *user_msgptr = string_split_message(*user_msgptr);
3679 if (fake_response != OK)
3680 fake_response_text = string_split_message(fake_response_text);
3687 /*************************************************
3688 * Create ACL variable *
3689 *************************************************/
3691 /* Create an ACL variable or reuse an existing one. ACL variables are in a
3692 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
3695 name pointer to the variable's name, starting with c or m
3697 Returns the pointer to variable's tree node
3701 acl_var_create(uschar *name)
3703 tree_node *node, **root;
3704 root = (name[0] == 'c')? &acl_var_c : &acl_var_m;
3705 node = tree_search(*root, name);
3708 node = store_get(sizeof(tree_node) + Ustrlen(name));
3709 Ustrcpy(node->name, name);
3710 (void)tree_insertnode(root, node);
3712 node->data.ptr = NULL;
3718 /*************************************************
3719 * Write an ACL variable in spool format *
3720 *************************************************/
3722 /* This function is used as a callback for tree_walk when writing variables to
3723 the spool file. To retain spool file compatibility, what is written is -aclc or
3724 -aclm followed by the rest of the name and the data length, space separated,
3725 then the value itself, starting on a new line, and terminated by an additional
3726 newline. When we had only numbered ACL variables, the first line might look
3727 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
3731 name of the variable
3732 value of the variable
3733 ctx FILE pointer (as a void pointer)
3739 acl_var_write(uschar *name, uschar *value, void *ctx)
3741 FILE *f = (FILE *)ctx;
3742 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);