1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Code for handling Access Control Lists (ACLs) */
13 /* Default callout timeout */
15 #define CALLOUT_TIMEOUT_DEFAULT 30
17 /* ACL verb codes - keep in step with the table of verbs that follows */
19 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
24 static uschar *verbs[] = {
33 /* For each verb, the conditions for which "message" or "log_message" are used
34 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
35 "accept", the FAIL case is used only after "endpass", but that is selected in
38 static int msgcond[] = {
39 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
42 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
44 (1<<FAIL) | (1<<FAIL_DROP), /* require */
48 /* ACL condition and modifier codes - keep in step with the table that
49 follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
55 #ifdef EXPERIMENTAL_BRIGHTMAIL
61 #ifdef EXPERIMENTAL_DCC
64 #ifdef WITH_CONTENT_SCAN
68 #ifdef WITH_OLD_DEMIME
75 #ifdef EXPERIMENTAL_DMARC
85 ACLC_LOG_REJECT_TARGET,
87 #ifdef WITH_CONTENT_SCAN
91 #ifdef WITH_CONTENT_SCAN
96 #ifdef WITH_CONTENT_SCAN
103 #ifdef WITH_CONTENT_SCAN
106 #ifdef EXPERIMENTAL_SPF
113 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
114 "message", "log_message", "log_reject_target", "logwrite", and "set" are
115 modifiers that look like conditions but always return TRUE. They are used for
116 their side effects. */
118 static uschar *conditions[] = {
122 #ifdef EXPERIMENTAL_BRIGHTMAIL
128 #ifdef EXPERIMENTAL_DCC
131 #ifdef WITH_CONTENT_SCAN
135 #ifdef WITH_OLD_DEMIME
142 #ifdef EXPERIMENTAL_DMARC
152 US"log_reject_target",
154 #ifdef WITH_CONTENT_SCAN
158 #ifdef WITH_CONTENT_SCAN
163 #ifdef WITH_CONTENT_SCAN
167 US"sender_domains", US"senders", US"set",
168 #ifdef WITH_CONTENT_SCAN
171 #ifdef EXPERIMENTAL_SPF
179 /* Return values from decode_control(); keep in step with the table of names
183 CONTROL_AUTH_UNADVERTISED,
184 #ifdef EXPERIMENTAL_BRIGHTMAIL
191 #ifdef EXPERIMENTAL_DMARC
192 CONTROL_DMARC_VERIFY,
193 CONTROL_DMARC_FORENSIC,
197 CONTROL_CASEFUL_LOCAL_PART,
198 CONTROL_CASELOWER_LOCAL_PART,
199 CONTROL_CUTTHROUGH_DELIVERY,
200 CONTROL_ENFORCE_SYNC,
201 CONTROL_NO_ENFORCE_SYNC,
205 CONTROL_SUPPRESS_LOCAL_FIXUPS,
206 #ifdef WITH_CONTENT_SCAN
207 CONTROL_NO_MBOX_UNSPOOL,
211 CONTROL_NO_MULTILINE,
212 CONTROL_NO_PIPELINING,
213 CONTROL_NO_DELAY_FLUSH,
214 CONTROL_NO_CALLOUT_FLUSH
217 /* ACL control names; keep in step with the table above! This list is used for
218 turning ids into names. The actual list of recognized names is in the variable
219 control_def controls_list[] below. The fact that there are two lists is a mess
220 and should be tidied up. */
222 static uschar *controls[] = {
223 US"allow_auth_unadvertised",
224 #ifdef EXPERIMENTAL_BRIGHTMAIL
229 US"dkim_disable_verify",
231 #ifdef EXPERIMENTAL_DMARC
232 US"dmarc_disable_verify",
233 US"dmarc_enable_forensic",
237 US"caseful_local_part",
238 US"caselower_local_part",
239 US"cutthrough_delivery",
245 US"suppress_local_fixups",
246 #ifdef WITH_CONTENT_SCAN
251 US"no_multiline_responses",
257 /* Flags to indicate for which conditions/modifiers a string expansion is done
258 at the outer level. In the other cases, expansion already occurs in the
259 checking functions. */
261 static uschar cond_expand_at_top[] = {
263 TRUE, /* add_header */
264 FALSE, /* authenticated */
265 #ifdef EXPERIMENTAL_BRIGHTMAIL
266 TRUE, /* bmi_optin */
268 TRUE, /* condition */
271 #ifdef EXPERIMENTAL_DCC
274 #ifdef WITH_CONTENT_SCAN
278 #ifdef WITH_OLD_DEMIME
282 TRUE, /* dkim_signers */
283 TRUE, /* dkim_status */
285 #ifdef EXPERIMENTAL_DMARC
286 TRUE, /* dmarc_status */
290 FALSE, /* encrypted */
293 FALSE, /* local_parts */
294 TRUE, /* log_message */
295 TRUE, /* log_reject_target */
297 #ifdef WITH_CONTENT_SCAN
301 #ifdef WITH_CONTENT_SCAN
302 TRUE, /* mime_regex */
304 TRUE, /* ratelimit */
305 FALSE, /* recipients */
306 #ifdef WITH_CONTENT_SCAN
309 TRUE, /* remove_header */
310 FALSE, /* sender_domains */
313 #ifdef WITH_CONTENT_SCAN
316 #ifdef EXPERIMENTAL_SPF
318 TRUE, /* spf_guess */
324 /* Flags to identify the modifiers */
326 static uschar cond_modifiers[] = {
328 TRUE, /* add_header */
329 FALSE, /* authenticated */
330 #ifdef EXPERIMENTAL_BRIGHTMAIL
331 TRUE, /* bmi_optin */
333 FALSE, /* condition */
336 #ifdef EXPERIMENTAL_DCC
339 #ifdef WITH_CONTENT_SCAN
343 #ifdef WITH_OLD_DEMIME
347 FALSE, /* dkim_signers */
348 FALSE, /* dkim_status */
350 #ifdef EXPERIMENTAL_DMARC
351 FALSE, /* dmarc_status */
353 FALSE, /* dnslists */
355 FALSE, /* encrypted */
358 FALSE, /* local_parts */
359 TRUE, /* log_message */
360 TRUE, /* log_reject_target */
362 #ifdef WITH_CONTENT_SCAN
366 #ifdef WITH_CONTENT_SCAN
367 FALSE, /* mime_regex */
369 FALSE, /* ratelimit */
370 FALSE, /* recipients */
371 #ifdef WITH_CONTENT_SCAN
374 TRUE, /* remove_header */
375 FALSE, /* sender_domains */
378 #ifdef WITH_CONTENT_SCAN
381 #ifdef EXPERIMENTAL_SPF
383 FALSE, /* spf_guess */
389 /* Bit map vector of which conditions and modifiers are not allowed at certain
390 times. For each condition and modifier, there's a bitmap of dis-allowed times.
391 For some, it is easier to specify the negation of a small number of allowed
394 static unsigned int cond_forbids[] = {
398 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
399 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
403 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
405 (1<<ACL_WHERE_NOTSMTP_START)),
407 (1<<ACL_WHERE_NOTSMTP)| /* authenticated */
408 (1<<ACL_WHERE_NOTSMTP_START)|
409 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
411 #ifdef EXPERIMENTAL_BRIGHTMAIL
412 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
413 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
414 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
418 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
419 (1<<ACL_WHERE_MAILAUTH)|
420 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
421 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
422 (1<<ACL_WHERE_NOTSMTP_START),
429 /* Certain types of control are always allowed, so we let it through
430 always and check in the control processing itself. */
434 #ifdef EXPERIMENTAL_DCC
436 ~((1<<ACL_WHERE_DATA)| /* dcc */
440 (1<<ACL_WHERE_NOTSMTP)),
443 #ifdef WITH_CONTENT_SCAN
445 ~(1<<ACL_WHERE_MIME), /* decode */
448 (1<<ACL_WHERE_NOTQUIT), /* delay */
450 #ifdef WITH_OLD_DEMIME
452 ~((1<<ACL_WHERE_DATA)| /* demime */
456 (1<<ACL_WHERE_NOTSMTP)),
461 ~(1<<ACL_WHERE_DKIM), /* dkim_signers */
464 ~(1<<ACL_WHERE_DKIM), /* dkim_status */
467 #ifdef EXPERIMENTAL_DMARC
469 ~(1<<ACL_WHERE_DATA), /* dmarc_status */
472 (1<<ACL_WHERE_NOTSMTP)| /* dnslists */
473 (1<<ACL_WHERE_NOTSMTP_START),
476 ~((1<<ACL_WHERE_RCPT) /* domains */
482 (1<<ACL_WHERE_NOTSMTP)| /* encrypted */
483 (1<<ACL_WHERE_CONNECT)|
484 (1<<ACL_WHERE_NOTSMTP_START)|
489 (1<<ACL_WHERE_NOTSMTP)| /* hosts */
490 (1<<ACL_WHERE_NOTSMTP_START),
493 ~((1<<ACL_WHERE_RCPT) /* local_parts */
501 0, /* log_reject_target */
505 #ifdef WITH_CONTENT_SCAN
507 ~((1<<ACL_WHERE_DATA)| /* malware */
511 (1<<ACL_WHERE_NOTSMTP)),
516 #ifdef WITH_CONTENT_SCAN
518 ~(1<<ACL_WHERE_MIME), /* mime_regex */
524 ~(1<<ACL_WHERE_RCPT), /* recipients */
526 #ifdef WITH_CONTENT_SCAN
528 ~((1<<ACL_WHERE_DATA)| /* regex */
532 (1<<ACL_WHERE_NOTSMTP)|
533 (1<<ACL_WHERE_MIME)),
537 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* remove_header */
538 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
542 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
543 (1<<ACL_WHERE_NOTSMTP_START)),
545 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
547 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
548 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
549 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
551 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
553 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
554 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
555 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
559 #ifdef WITH_CONTENT_SCAN
561 ~((1<<ACL_WHERE_DATA)| /* spam */
565 (1<<ACL_WHERE_NOTSMTP)),
568 #ifdef EXPERIMENTAL_SPF
569 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
571 (1<<ACL_WHERE_MAILAUTH)|
572 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
573 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
574 (1<<ACL_WHERE_NOTSMTP)|
575 (1<<ACL_WHERE_NOTSMTP_START),
577 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf_guess */
579 (1<<ACL_WHERE_MAILAUTH)|
580 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
581 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
582 (1<<ACL_WHERE_NOTSMTP)|
583 (1<<ACL_WHERE_NOTSMTP_START),
588 /* Certain types of verify are always allowed, so we let it through
589 always and check in the verify function itself */
595 /* Bit map vector of which controls are not allowed at certain times. For
596 each control, there's a bitmap of dis-allowed times. For some, it is easier to
597 specify the negation of a small number of allowed times. */
599 static unsigned int control_forbids[] = {
601 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
603 #ifdef EXPERIMENTAL_BRIGHTMAIL
610 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_disable_verify */
614 (1<<ACL_WHERE_NOTSMTP_START),
617 #ifdef EXPERIMENTAL_DMARC
618 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dmarc_disable_verify */
619 (1<<ACL_WHERE_NOTSMTP_START),
620 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dmarc_enable_forensic */
621 (1<<ACL_WHERE_NOTSMTP_START),
624 (1<<ACL_WHERE_NOTSMTP)|
625 (1<<ACL_WHERE_NOTSMTP_START)|
626 (1<<ACL_WHERE_NOTQUIT), /* dscp */
631 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
634 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
637 0, /* cutthrough_delivery */
639 (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
640 (1<<ACL_WHERE_NOTSMTP_START),
642 (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
643 (1<<ACL_WHERE_NOTSMTP_START),
646 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
647 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
648 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
649 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
652 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
653 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
654 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
655 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
658 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
659 (1<<ACL_WHERE_PREDATA)),
662 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
663 (1<<ACL_WHERE_PREDATA)|
664 (1<<ACL_WHERE_NOTSMTP_START)),
666 #ifdef WITH_CONTENT_SCAN
668 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
669 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
670 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
671 (1<<ACL_WHERE_MIME)),
675 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
676 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
680 (1<<ACL_WHERE_MIME)),
683 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
684 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
688 (1<<ACL_WHERE_MIME)),
690 (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
691 (1<<ACL_WHERE_NOTSMTP_START),
693 (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
694 (1<<ACL_WHERE_NOTSMTP_START),
696 (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
697 (1<<ACL_WHERE_NOTSMTP_START),
699 (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
700 (1<<ACL_WHERE_NOTSMTP_START)
703 /* Structure listing various control arguments, with their characteristics. */
705 typedef struct control_def {
707 int value; /* CONTROL_xxx value */
708 BOOL has_option; /* Has /option(s) following */
711 static control_def controls_list[] = {
712 { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
713 #ifdef EXPERIMENTAL_BRIGHTMAIL
714 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
716 { US"debug", CONTROL_DEBUG, TRUE },
718 { US"dkim_disable_verify", CONTROL_DKIM_VERIFY, FALSE },
720 #ifdef EXPERIMENTAL_DMARC
721 { US"dmarc_disable_verify", CONTROL_DMARC_VERIFY, FALSE },
722 { US"dmarc_enable_forensic", CONTROL_DMARC_FORENSIC, FALSE },
724 { US"dscp", CONTROL_DSCP, TRUE },
725 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
726 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
727 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
728 { US"freeze", CONTROL_FREEZE, TRUE },
729 { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
730 { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
731 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
732 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
733 { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
734 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
735 #ifdef WITH_CONTENT_SCAN
736 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
738 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
739 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
740 { US"submission", CONTROL_SUBMISSION, TRUE },
741 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE },
742 { US"cutthrough_delivery", CONTROL_CUTTHROUGH_DELIVERY, FALSE }
745 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
746 caches its result in a tree to avoid repeated DNS queries. The result is an
747 integer code which is used as an index into the following tables of
748 explanatory strings and verification return codes. */
750 static tree_node *csa_cache = NULL;
752 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
753 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
755 /* The acl_verify_csa() return code is translated into an acl_verify() return
756 code using the following table. It is OK unless the client is definitely not
757 authorized. This is because CSA is supposed to be optional for sending sites,
758 so recipients should not be too strict about checking it - especially because
759 DNS problems are quite likely to occur. It's possible to use $csa_status in
760 further ACL conditions to distinguish ok, unknown, and defer if required, but
761 the aim is to make the usual configuration simple. */
763 static int csa_return_code[] = {
765 FAIL, FAIL, FAIL, FAIL
768 static uschar *csa_status_string[] = {
769 US"unknown", US"ok", US"defer", US"defer",
770 US"fail", US"fail", US"fail", US"fail"
773 static uschar *csa_reason_string[] = {
776 US"deferred (SRV lookup failed)",
777 US"deferred (target address lookup failed)",
778 US"failed (explicit authorization required)",
779 US"failed (host name not authorized)",
780 US"failed (no authorized addresses)",
781 US"failed (client address mismatch)"
784 /* Options for the ratelimit condition. Note that there are two variants of
785 the per_rcpt option, depending on the ACL that is used to measure the rate.
786 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
787 so the two variants must have the same internal representation as well as
788 the same configuration string. */
791 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
792 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
795 #define RATE_SET(var,new) \
796 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
798 static uschar *ratelimit_option_string[] = {
799 US"?", US"!", US"per_addr", US"per_byte", US"per_cmd",
800 US"per_conn", US"per_mail", US"per_rcpt", US"per_rcpt"
803 /* Enable recursion between acl_check_internal() and acl_check_condition() */
805 static int acl_check_wargs(int, address_item *, const uschar *, int, uschar **,
809 /*************************************************
810 * Pick out name from list *
811 *************************************************/
813 /* Use a binary chop method
820 Returns: offset in list, or -1 if not found
824 acl_checkname(uschar *name, uschar **list, int end)
830 int mid = (start + end)/2;
831 int c = Ustrcmp(name, list[mid]);
832 if (c == 0) return mid;
833 if (c < 0) end = mid; else start = mid + 1;
840 /*************************************************
841 * Read and parse one ACL *
842 *************************************************/
844 /* This function is called both from readconf in order to parse the ACLs in the
845 configuration file, and also when an ACL is encountered dynamically (e.g. as
846 the result of an expansion). It is given a function to call in order to
847 retrieve the lines of the ACL. This function handles skipping comments and
848 blank lines (where relevant).
851 func function to get next line of ACL
852 error where to put an error message
854 Returns: pointer to ACL, or NULL
855 NULL can be legal (empty ACL); in this case error will be NULL
859 acl_read(uschar *(*func)(void), uschar **error)
861 acl_block *yield = NULL;
862 acl_block **lastp = &yield;
863 acl_block *this = NULL;
864 acl_condition_block *cond;
865 acl_condition_block **condp = NULL;
870 while ((s = (*func)()) != NULL)
873 BOOL negated = FALSE;
874 uschar *saveline = s;
877 /* Conditions (but not verbs) are allowed to be negated by an initial
880 while (isspace(*s)) s++;
887 /* Read the name of a verb or a condition, or the start of a new ACL, which
888 can be started by a name, or by a macro definition. */
890 s = readconf_readname(name, sizeof(name), s);
891 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
893 /* If a verb is unrecognized, it may be another condition or modifier that
894 continues the previous verb. */
896 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
901 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
913 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
916 this = store_get(sizeof(acl_block));
918 lastp = &(this->next);
921 this->condition = NULL;
922 condp = &(this->condition);
923 if (*s == 0) continue; /* No condition on this line */
929 s = readconf_readname(name, sizeof(name), s); /* Condition name */
932 /* Handle a condition or modifier. */
934 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
937 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
942 /* The modifiers may not be negated */
944 if (negated && cond_modifiers[c])
946 *error = string_sprintf("ACL error: negation is not allowed with "
947 "\"%s\"", conditions[c]);
951 /* ENDPASS may occur only with ACCEPT or DISCARD. */
953 if (c == ACLC_ENDPASS &&
954 this->verb != ACL_ACCEPT &&
955 this->verb != ACL_DISCARD)
957 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
958 conditions[c], verbs[this->verb]);
962 cond = store_get(sizeof(acl_condition_block));
965 cond->u.negated = negated;
968 condp = &(cond->next);
970 /* The "set" modifier is different in that its argument is "name=value"
971 rather than just a value, and we can check the validity of the name, which
972 gives us a variable name to insert into the data block. The original ACL
973 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
974 extended to 20 of each type, but after that people successfully argued for
975 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
976 After that, we allow alphanumerics and underscores, but the first character
977 after c or m must be a digit or an underscore. This retains backwards
984 if (Ustrncmp(s, "acl_c", 5) != 0 &&
985 Ustrncmp(s, "acl_m", 5) != 0)
987 *error = string_sprintf("invalid variable name after \"set\" in ACL "
988 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
993 if (!isdigit(*endptr) && *endptr != '_')
995 *error = string_sprintf("invalid variable name after \"set\" in ACL "
996 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
1001 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
1003 if (!isalnum(*endptr) && *endptr != '_')
1005 *error = string_sprintf("invalid character \"%c\" in variable name "
1006 "in ACL modifier \"set %s\"", *endptr, s);
1012 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
1014 while (isspace(*s)) s++;
1017 /* For "set", we are now positioned for the data. For the others, only
1018 "endpass" has no data */
1020 if (c != ACLC_ENDPASS)
1024 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
1025 cond_modifiers[c]? US"modifier" : US"condition");
1028 while (isspace(*s)) s++;
1029 cond->arg = string_copy(s);
1038 /*************************************************
1039 * Set up added header line(s) *
1040 *************************************************/
1042 /* This function is called by the add_header modifier, and also from acl_warn()
1043 to implement the now-deprecated way of adding header lines using "message" on a
1044 "warn" verb. The argument is treated as a sequence of header lines which are
1045 added to a chain, provided there isn't an identical one already there.
1047 Argument: string of header lines
1052 setup_header(const uschar *hstring)
1054 const uschar *p, *q;
1055 int hlen = Ustrlen(hstring);
1057 /* Ignore any leading newlines */
1058 while (*hstring == '\n') hstring++, hlen--;
1060 /* An empty string does nothing; ensure exactly one final newline. */
1061 if (hlen <= 0) return;
1062 if (hstring[--hlen] != '\n')
1063 q = string_sprintf("%s\n", hstring);
1064 else if (hstring[hlen-1] == '\n')
1066 uschar * s = string_copy(hstring);
1067 while(s[--hlen] == '\n')
1074 /* Loop for multiple header lines, taking care about continuations */
1076 for (p = q; *p != 0; )
1080 int newtype = htype_add_bot;
1081 header_line **hptr = &acl_added_headers;
1083 /* Find next header line within the string */
1087 q = Ustrchr(q, '\n');
1088 if (*(++q) != ' ' && *q != '\t') break;
1091 /* If the line starts with a colon, interpret the instruction for where to
1092 add it. This temporarily sets up a new type. */
1096 if (strncmpic(p, US":after_received:", 16) == 0)
1098 newtype = htype_add_rec;
1101 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
1103 newtype = htype_add_rfc;
1106 else if (strncmpic(p, US":at_start:", 10) == 0)
1108 newtype = htype_add_top;
1111 else if (strncmpic(p, US":at_end:", 8) == 0)
1113 newtype = htype_add_bot;
1116 while (*p == ' ' || *p == '\t') p++;
1119 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1120 to the front of it. */
1122 for (s = p; s < q - 1; s++)
1124 if (*s == ':' || !isgraph(*s)) break;
1127 hdr = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
1128 hlen = Ustrlen(hdr);
1130 /* See if this line has already been added */
1132 while (*hptr != NULL)
1134 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1135 hptr = &((*hptr)->next);
1138 /* Add if not previously present */
1142 header_line *h = store_get(sizeof(header_line));
1151 /* Advance for next header line within the string */
1159 /*************************************************
1160 * List the added header lines *
1161 *************************************************/
1165 uschar * ret = NULL;
1166 header_line * h = acl_added_headers;
1172 if (!h) return NULL;
1177 while ((cp = Ustrchr(s, '\n')) != NULL)
1179 if (cp[1] == '\0') break;
1181 /* contains embedded newline; needs doubling */
1182 ret = string_cat(ret, &size, &ptr, s, cp-s+1);
1183 ret = string_cat(ret, &size, &ptr, US"\n", 1);
1186 /* last bit of header */
1188 ret = string_cat(ret, &size, &ptr, s, cp-s+1); /* newline-sep list */
1190 while((h = h->next));
1192 ret[ptr-1] = '\0'; /* overwrite last newline */
1197 /*************************************************
1198 * Set up removed header line(s) *
1199 *************************************************/
1201 /* This function is called by the remove_header modifier. The argument is
1202 treated as a sequence of header names which are added to a colon separated
1203 list, provided there isn't an identical one already there.
1205 Argument: string of header names
1210 setup_remove_header(const uschar *hnames)
1213 acl_removed_headers = acl_removed_headers
1214 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1215 : string_copy(hnames);
1220 /*************************************************
1222 *************************************************/
1224 /* This function is called when a WARN verb's conditions are true. It adds to
1225 the message's headers, and/or writes information to the log. In each case, this
1226 only happens once (per message for headers, per connection for log).
1228 ** NOTE: The header adding action using the "message" setting is historic, and
1229 its use is now deprecated. The new add_header modifier should be used instead.
1232 where ACL_WHERE_xxxx indicating which ACL this is
1233 user_message message for adding to headers
1234 log_message message for logging, if different
1240 acl_warn(int where, uschar *user_message, uschar *log_message)
1242 if (log_message != NULL && log_message != user_message)
1245 string_item *logged;
1247 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1248 string_printing(log_message));
1250 /* If a sender verification has failed, and the log message is "sender verify
1251 failed", add the failure message. */
1253 if (sender_verified_failed != NULL &&
1254 sender_verified_failed->message != NULL &&
1255 strcmpic(log_message, US"sender verify failed") == 0)
1256 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1258 /* Search previously logged warnings. They are kept in malloc
1259 store so they can be freed at the start of a new message. */
1261 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1262 if (Ustrcmp(logged->text, text) == 0) break;
1266 int length = Ustrlen(text) + 1;
1267 log_write(0, LOG_MAIN, "%s", text);
1268 logged = store_malloc(sizeof(string_item) + length);
1269 logged->text = (uschar *)logged + sizeof(string_item);
1270 memcpy(logged->text, text, length);
1271 logged->next = acl_warn_logged;
1272 acl_warn_logged = logged;
1276 /* If there's no user message, we are done. */
1278 if (user_message == NULL) return;
1280 /* If this isn't a message ACL, we can't do anything with a user message.
1283 if (where > ACL_WHERE_NOTSMTP)
1285 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1286 "found in a non-message (%s) ACL: cannot specify header lines here: "
1287 "message ignored", acl_wherenames[where]);
1291 /* The code for setting up header lines is now abstracted into a separate
1292 function so that it can be used for the add_header modifier as well. */
1294 setup_header(user_message);
1299 /*************************************************
1300 * Verify and check reverse DNS *
1301 *************************************************/
1303 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1304 address if this has not yet been done. The host_name_lookup() function checks
1305 that one of these names resolves to an address list that contains the client IP
1306 address, so we don't actually have to do the check here.
1309 user_msgptr pointer for user message
1310 log_msgptr pointer for log message
1312 Returns: OK verification condition succeeded
1313 FAIL verification failed
1314 DEFER there was a problem verifying
1318 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1322 user_msgptr = user_msgptr; /* stop compiler warning */
1324 /* Previous success */
1326 if (sender_host_name != NULL) return OK;
1328 /* Previous failure */
1330 if (host_lookup_failed)
1332 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1336 /* Need to do a lookup */
1339 debug_printf("looking up host name to force name/address consistency check\n");
1341 if ((rc = host_name_lookup()) != OK)
1343 *log_msgptr = (rc == DEFER)?
1344 US"host lookup deferred for reverse lookup check"
1346 string_sprintf("host lookup failed for reverse lookup check%s",
1348 return rc; /* DEFER or FAIL */
1351 host_build_sender_fullhost();
1357 /*************************************************
1358 * Check client IP address matches CSA target *
1359 *************************************************/
1361 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1362 response for address records belonging to the CSA target hostname. The section
1363 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1364 If one of the addresses matches the client's IP address, then the client is
1365 authorized by CSA. If there are target IP addresses but none of them match
1366 then the client is using an unauthorized IP address. If there are no target IP
1367 addresses then the client cannot be using an authorized IP address. (This is
1368 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1371 dnsa the DNS answer block
1372 dnss a DNS scan block for us to use
1373 reset option specifing what portion to scan, as described above
1374 target the target hostname to use for matching RR names
1376 Returns: CSA_OK successfully authorized
1377 CSA_FAIL_MISMATCH addresses found but none matched
1378 CSA_FAIL_NOADDR no target addresses found
1382 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1388 BOOL target_found = FALSE;
1390 for (rr = dns_next_rr(dnsa, dnss, reset);
1392 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1394 /* Check this is an address RR for the target hostname. */
1398 && rr->type != T_AAAA
1402 if (strcmpic(target, rr->name) != 0) continue;
1404 target_found = TRUE;
1406 /* Turn the target address RR into a list of textual IP addresses and scan
1407 the list. There may be more than one if it is an A6 RR. */
1409 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1411 /* If the client IP address matches the target IP address, it's good! */
1413 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1415 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1419 /* If we found some target addresses but none of them matched, the client is
1420 using an unauthorized IP address, otherwise the target has no authorized IP
1423 if (target_found) return CSA_FAIL_MISMATCH;
1424 else return CSA_FAIL_NOADDR;
1429 /*************************************************
1430 * Verify Client SMTP Authorization *
1431 *************************************************/
1433 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1434 to find the CSA SRV record corresponding to the domain argument, or
1435 $sender_helo_name if no argument is provided. It then checks that the
1436 client is authorized, and that its IP address corresponds to the SRV
1437 target's address by calling acl_verify_csa_address() above. The address
1438 should have been returned in the DNS response's ADDITIONAL section, but if
1439 not we perform another DNS lookup to get it.
1442 domain pointer to optional parameter following verify = csa
1444 Returns: CSA_UNKNOWN no valid CSA record found
1445 CSA_OK successfully authorized
1446 CSA_FAIL_* client is definitely not authorized
1447 CSA_DEFER_* there was a DNS problem
1451 acl_verify_csa(const uschar *domain)
1454 const uschar *found;
1456 int priority, weight, port;
1463 /* Work out the domain we are using for the CSA lookup. The default is the
1464 client's HELO domain. If the client has not said HELO, use its IP address
1465 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1467 while (isspace(*domain) && *domain != '\0') ++domain;
1468 if (*domain == '\0') domain = sender_helo_name;
1469 if (domain == NULL) domain = sender_host_address;
1470 if (sender_host_address == NULL) return CSA_UNKNOWN;
1472 /* If we have an address literal, strip off the framing ready for turning it
1473 into a domain. The framing consists of matched square brackets possibly
1474 containing a keyword and a colon before the actual IP address. */
1476 if (domain[0] == '[')
1478 const uschar *start = Ustrchr(domain, ':');
1479 if (start == NULL) start = domain;
1480 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1483 /* Turn domains that look like bare IP addresses into domains in the reverse
1484 DNS. This code also deals with address literals and $sender_host_address. It's
1485 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1486 address literals, but it's probably the most friendly thing to do. This is an
1487 extension to CSA, so we allow it to be turned off for proper conformance. */
1489 if (string_is_ip_address(domain, NULL) != 0)
1491 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1492 dns_build_reverse(domain, target);
1496 /* Find out if we've already done the CSA check for this domain. If we have,
1497 return the same result again. Otherwise build a new cached result structure
1498 for this domain. The name is filled in now, and the value is filled in when
1499 we return from this function. */
1501 t = tree_search(csa_cache, domain);
1502 if (t != NULL) return t->data.val;
1504 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1505 Ustrcpy(t->name, domain);
1506 (void)tree_insertnode(&csa_cache, t);
1508 /* Now we are ready to do the actual DNS lookup(s). */
1511 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1513 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1516 return t->data.val = CSA_DEFER_SRV;
1518 /* If we found nothing, the client's authorization is unknown. */
1522 return t->data.val = CSA_UNKNOWN;
1524 /* We got something! Go on to look at the reply in more detail. */
1530 /* Scan the reply for well-formed CSA SRV records. */
1532 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1534 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1536 if (rr->type != T_SRV) continue;
1538 /* Extract the numerical SRV fields (p is incremented) */
1541 GETSHORT(priority, p);
1542 GETSHORT(weight, p);
1546 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1548 /* Check the CSA version number */
1550 if (priority != 1) continue;
1552 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1553 found by dns_special_lookup() is a parent of the one we asked for), we check
1554 the subdomain assertions in the port field. At the moment there's only one
1555 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1556 SRV records of their own. */
1558 if (Ustrcmp(found, domain) != 0)
1561 return t->data.val = CSA_FAIL_EXPLICIT;
1563 return t->data.val = CSA_UNKNOWN;
1566 /* This CSA SRV record refers directly to our domain, so we check the value
1567 in the weight field to work out the domain's authorization. 0 and 1 are
1568 unauthorized; 3 means the client is authorized but we can't check the IP
1569 address in order to authenticate it, so we treat it as unknown; values
1570 greater than 3 are undefined. */
1572 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1574 if (weight > 2) continue;
1576 /* Weight == 2, which means the domain is authorized. We must check that the
1577 client's IP address is listed as one of the SRV target addresses. Save the
1578 target hostname then break to scan the additional data for its addresses. */
1580 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1581 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1583 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1588 /* If we didn't break the loop then no appropriate records were found. */
1590 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1592 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1593 A target of "." indicates there are no valid addresses, so the client cannot
1594 be authorized. (This is an odd configuration because weight=2 target=. is
1595 equivalent to weight=1, but we check for it in order to keep load off the
1596 root name servers.) Note that dn_expand() turns "." into "". */
1598 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1600 /* Scan the additional section of the CSA SRV reply for addresses belonging
1601 to the target. If the name server didn't return any additional data (e.g.
1602 because it does not fully support SRV records), we need to do another lookup
1603 to obtain the target addresses; otherwise we have a definitive result. */
1605 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1606 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1608 /* The DNS lookup type corresponds to the IP version used by the client. */
1611 if (Ustrchr(sender_host_address, ':') != NULL)
1614 #endif /* HAVE_IPV6 */
1618 lookup_dnssec_authenticated = NULL;
1619 switch (dns_lookup(&dnsa, target, type, NULL))
1621 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1624 return t->data.val = CSA_DEFER_ADDR;
1626 /* If the query succeeded, scan the addresses and return the result. */
1629 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1630 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1631 /* else fall through */
1633 /* If the target has no IP addresses, the client cannot have an authorized
1634 IP address. However, if the target site uses A6 records (not AAAA records)
1635 we have to do yet another lookup in order to check them. */
1639 return t->data.val = CSA_FAIL_NOADDR;
1645 /*************************************************
1646 * Handle verification (address & other) *
1647 *************************************************/
1649 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1650 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1651 VERIFY_HDR_NAMES_ASCII
1656 unsigned where_allowed; /* bitmap */
1657 BOOL no_options; /* Never has /option(s) following */
1658 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1660 static verify_type_t verify_type_list[] = {
1661 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, FALSE, 0 },
1662 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1663 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1664 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1665 { US"header_syntax", VERIFY_HDR_SYNTAX, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1666 { US"not_blind", VERIFY_NOT_BLIND, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1667 { US"header_sender", VERIFY_HDR_SNDR, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), FALSE, 0 },
1668 { US"sender", VERIFY_SNDR, (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)
1669 |(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP),
1671 { US"recipient", VERIFY_RCPT, (1<<ACL_WHERE_RCPT), FALSE, 0 },
1672 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 }
1676 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1677 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1678 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1685 BOOL has_option; /* Has =option(s) following */
1686 BOOL timeval; /* Has a time value */
1688 static callout_opt_t callout_opt_list[] = {
1689 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1690 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1691 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1692 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1693 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1694 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1695 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1696 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1697 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1698 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1699 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1700 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1705 /* This function implements the "verify" condition. It is called when
1706 encountered in any ACL, because some tests are almost always permitted. Some
1707 just don't make sense, and always fail (for example, an attempt to test a host
1708 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1711 where where called from
1712 addr the recipient address that the ACL is handling, or NULL
1713 arg the argument of "verify"
1714 user_msgptr pointer for user message
1715 log_msgptr pointer for log message
1716 basic_errno where to put verify errno
1718 Returns: OK verification condition succeeded
1719 FAIL verification failed
1720 DEFER there was a problem verifying
1725 acl_verify(int where, address_item *addr, const uschar *arg,
1726 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1730 int callout_overall = -1;
1731 int callout_connect = -1;
1732 int verify_options = 0;
1734 BOOL verify_header_sender = FALSE;
1735 BOOL defer_ok = FALSE;
1736 BOOL callout_defer_ok = FALSE;
1737 BOOL no_details = FALSE;
1738 BOOL success_on_redirect = FALSE;
1739 address_item *sender_vaddr = NULL;
1740 uschar *verify_sender_address = NULL;
1741 uschar *pm_mailfrom = NULL;
1742 uschar *se_mailfrom = NULL;
1744 /* Some of the verify items have slash-separated options; some do not. Diagnose
1745 an error if options are given for items that don't expect them.
1748 uschar *slash = Ustrchr(arg, '/');
1749 const uschar *list = arg;
1750 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1753 if (ss == NULL) goto BAD_VERIFY;
1755 /* Handle name/address consistency verification in a separate function. */
1757 for (vp= verify_type_list;
1758 (char *)vp < (char *)verify_type_list + sizeof(verify_type_list);
1761 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1762 : strcmpic (ss, vp->name) == 0)
1764 if ((char *)vp >= (char *)verify_type_list + sizeof(verify_type_list))
1767 if (vp->no_options && slash != NULL)
1769 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1770 "(this verify item has no options)", arg);
1773 if (!(vp->where_allowed & (1<<where)))
1775 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", vp->name, acl_wherenames[where]);
1780 case VERIFY_REV_HOST_LKUP:
1781 if (sender_host_address == NULL) return OK;
1782 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1783 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1784 if (strcmpic(ss, US"defer_ok") == 0)
1789 /* TLS certificate verification is done at STARTTLS time; here we just
1790 test whether it was successful or not. (This is for optional verification; for
1791 mandatory verification, the connection doesn't last this long.) */
1793 if (tls_in.certificate_verified) return OK;
1794 *user_msgptr = US"no verified certificate";
1798 /* We can test the result of optional HELO verification that might have
1799 occurred earlier. If not, we can attempt the verification now. */
1801 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1802 return helo_verified? OK : FAIL;
1805 /* Do Client SMTP Authorization checks in a separate function, and turn the
1806 result code into user-friendly strings. */
1808 rc = acl_verify_csa(list);
1809 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1810 csa_reason_string[rc]);
1811 csa_status = csa_status_string[rc];
1812 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1813 return csa_return_code[rc];
1815 case VERIFY_HDR_SYNTAX:
1816 /* Check that all relevant header lines have the correct syntax. If there is
1817 a syntax error, we return details of the error to the sender if configured to
1818 send out full details. (But a "message" setting on the ACL can override, as
1821 rc = verify_check_headers(log_msgptr);
1822 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1823 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1826 case VERIFY_HDR_NAMES_ASCII:
1827 /* Check that all header names are true 7 bit strings
1828 See RFC 5322, 2.2. and RFC 6532, 3. */
1830 rc = verify_check_header_names_ascii(log_msgptr);
1831 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1832 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1835 case VERIFY_NOT_BLIND:
1836 /* Check that no recipient of this message is "blind", that is, every envelope
1837 recipient must be mentioned in either To: or Cc:. */
1839 rc = verify_check_notblind();
1842 *log_msgptr = string_sprintf("bcc recipient detected");
1843 if (smtp_return_error_details)
1844 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1848 /* The remaining verification tests check recipient and sender addresses,
1849 either from the envelope or from the header. There are a number of
1850 slash-separated options that are common to all of them. */
1852 case VERIFY_HDR_SNDR:
1853 verify_header_sender = TRUE;
1857 /* In the case of a sender, this can optionally be followed by an address to use
1858 in place of the actual sender (rare special-case requirement). */
1862 verify_sender_address = sender_address;
1865 while (isspace(*s)) s++;
1866 if (*s++ != '=') goto BAD_VERIFY;
1867 while (isspace(*s)) s++;
1868 verify_sender_address = string_copy(s);
1879 /* Remaining items are optional; they apply to sender and recipient
1880 verification, including "header sender" verification. */
1882 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1885 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1886 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1887 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1889 /* These two old options are left for backwards compatibility */
1891 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1893 callout_defer_ok = TRUE;
1894 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1897 else if (strcmpic(ss, US"check_postmaster") == 0)
1900 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1903 /* The callout option has a number of sub-options, comma separated */
1905 else if (strncmpic(ss, US"callout", 7) == 0)
1907 callout = CALLOUT_TIMEOUT_DEFAULT;
1911 while (isspace(*ss)) ss++;
1914 const uschar * sublist = ss;
1918 while (isspace(*sublist)) sublist++;
1920 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer)))
1924 double period = 1.0F;
1926 for (op= callout_opt_list; op->name; op++)
1927 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1930 verify_options |= op->flag;
1933 opt += Ustrlen(op->name);
1934 while (isspace(*opt)) opt++;
1937 *log_msgptr = string_sprintf("'=' expected after "
1938 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1941 while (isspace(*opt)) opt++;
1945 period = readconf_readtime(opt, 0, FALSE);
1948 *log_msgptr = string_sprintf("bad time value in ACL condition "
1949 "\"verify %s\"", arg);
1956 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1957 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1958 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1959 case CALLOUT_MAILFROM:
1960 if (!verify_header_sender)
1962 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1963 "callout option only for verify=header_sender (detected in ACL "
1964 "condition \"%s\")", arg);
1967 se_mailfrom = string_copy(opt);
1969 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1970 case CALLOUT_MAXWAIT: callout_overall = period; break;
1971 case CALLOUT_CONNECT: callout_connect = period; break;
1972 case CALLOUT_TIME: callout = period; break;
1978 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1979 "ACL condition \"%s\"", arg);
1985 /* Option not recognized */
1989 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1990 "condition \"verify %s\"", ss, arg);
1995 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1996 (vopt_callout_recipsender|vopt_callout_recippmaster))
1998 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1999 "for a recipient callout";
2003 /* Handle sender-in-header verification. Default the user message to the log
2004 message if giving out verification details. */
2006 if (verify_header_sender)
2009 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
2010 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
2014 *basic_errno = verrno;
2015 if (smtp_return_error_details)
2017 if (*user_msgptr == NULL && *log_msgptr != NULL)
2018 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
2019 if (rc == DEFER) acl_temp_details = TRUE;
2024 /* Handle a sender address. The default is to verify *the* sender address, but
2025 optionally a different address can be given, for special requirements. If the
2026 address is empty, we are dealing with a bounce message that has no sender, so
2027 we cannot do any checking. If the real sender address gets rewritten during
2028 verification (e.g. DNS widening), set the flag to stop it being rewritten again
2029 during message reception.
2031 A list of verified "sender" addresses is kept to try to avoid doing to much
2032 work repetitively when there are multiple recipients in a message and they all
2033 require sender verification. However, when callouts are involved, it gets too
2034 complicated because different recipients may require different callout options.
2035 Therefore, we always do a full sender verify when any kind of callout is
2036 specified. Caching elsewhere, for instance in the DNS resolver and in the
2037 callout handling, should ensure that this is not terribly inefficient. */
2039 else if (verify_sender_address != NULL)
2041 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
2044 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
2045 "sender verify callout";
2049 sender_vaddr = verify_checked_sender(verify_sender_address);
2050 if (sender_vaddr != NULL && /* Previously checked */
2051 callout <= 0) /* No callout needed this time */
2053 /* If the "routed" flag is set, it means that routing worked before, so
2054 this check can give OK (the saved return code value, if set, belongs to a
2055 callout that was done previously). If the "routed" flag is not set, routing
2056 must have failed, so we use the saved return code. */
2058 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
2060 rc = sender_vaddr->special_action;
2061 *basic_errno = sender_vaddr->basic_errno;
2063 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
2066 /* Do a new verification, and cache the result. The cache is used to avoid
2067 verifying the sender multiple times for multiple RCPTs when callouts are not
2068 specified (see comments above).
2070 The cache is also used on failure to give details in response to the first
2071 RCPT that gets bounced for this reason. However, this can be suppressed by
2072 the no_details option, which sets the flag that says "this detail has already
2073 been sent". The cache normally contains just one address, but there may be
2074 more in esoteric circumstances. */
2079 uschar *save_address_data = deliver_address_data;
2081 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
2082 #ifdef EXPERIMENTAL_INTERNATIONAL
2083 sender_vaddr->p.utf8 = message_smtputf8;
2085 if (no_details) setflag(sender_vaddr, af_sverify_told);
2086 if (verify_sender_address[0] != 0)
2088 /* If this is the real sender address, save the unrewritten version
2089 for use later in receive. Otherwise, set a flag so that rewriting the
2090 sender in verify_address() does not update sender_address. */
2092 if (verify_sender_address == sender_address)
2093 sender_address_unrewritten = sender_address;
2095 verify_options |= vopt_fake_sender;
2097 if (success_on_redirect)
2098 verify_options |= vopt_success_on_redirect;
2100 /* The recipient, qualify, and expn options are never set in
2103 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2104 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2106 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
2110 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2112 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
2113 verify_sender_address, sender_vaddr->address);
2117 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
2118 verify_sender_address);
2121 else *basic_errno = sender_vaddr->basic_errno;
2123 else rc = OK; /* Null sender */
2125 /* Cache the result code */
2127 if (routed) setflag(sender_vaddr, af_verify_routed);
2128 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2129 sender_vaddr->special_action = rc;
2130 sender_vaddr->next = sender_verified_list;
2131 sender_verified_list = sender_vaddr;
2133 /* Restore the recipient address data, which might have been clobbered by
2134 the sender verification. */
2136 deliver_address_data = save_address_data;
2139 /* Put the sender address_data value into $sender_address_data */
2141 sender_address_data = sender_vaddr->p.address_data;
2144 /* A recipient address just gets a straightforward verify; again we must handle
2145 the DEFER overrides. */
2151 if (success_on_redirect)
2152 verify_options |= vopt_success_on_redirect;
2154 /* We must use a copy of the address for verification, because it might
2158 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2159 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2160 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
2162 *basic_errno = addr2.basic_errno;
2163 *log_msgptr = addr2.message;
2164 *user_msgptr = (addr2.user_message != NULL)?
2165 addr2.user_message : addr2.message;
2167 /* Allow details for temporary error if the address is so flagged. */
2168 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
2170 /* Make $address_data visible */
2171 deliver_address_data = addr2.p.address_data;
2174 /* We have a result from the relevant test. Handle defer overrides first. */
2176 if (rc == DEFER && (defer_ok ||
2177 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2179 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
2180 defer_ok? "defer_ok" : "callout_defer_ok");
2184 /* If we've failed a sender, set up a recipient message, and point
2185 sender_verified_failed to the address item that actually failed. */
2187 if (rc != OK && verify_sender_address != NULL)
2191 *log_msgptr = *user_msgptr = US"Sender verify failed";
2193 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2195 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2199 *log_msgptr = US"Could not complete sender verify callout";
2200 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2204 sender_verified_failed = sender_vaddr;
2207 /* Verifying an address messes up the values of $domain and $local_part,
2208 so reset them before returning if this is a RCPT ACL. */
2212 deliver_domain = addr->domain;
2213 deliver_localpart = addr->local_part;
2217 /* Syntax errors in the verify argument come here. */
2220 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2221 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2222 "or \"reverse_host_lookup\" at start of ACL condition "
2223 "\"verify %s\"", arg);
2230 /*************************************************
2231 * Check argument for control= modifier *
2232 *************************************************/
2234 /* Called from acl_check_condition() below
2237 arg the argument string for control=
2238 pptr set to point to the terminating character
2239 where which ACL we are in
2240 log_msgptr for error messages
2242 Returns: CONTROL_xxx value
2246 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2251 for (d = controls_list;
2252 d < controls_list + sizeof(controls_list)/sizeof(control_def);
2255 len = Ustrlen(d->name);
2256 if (Ustrncmp(d->name, arg, len) == 0) break;
2259 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
2260 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
2262 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2263 return CONTROL_ERROR;
2273 /*************************************************
2274 * Return a ratelimit error *
2275 *************************************************/
2277 /* Called from acl_ratelimit() below
2280 log_msgptr for error messages
2281 format format string
2282 ... supplementary arguments
2283 ss ratelimit option name
2284 where ACL_WHERE_xxxx indicating which ACL this is
2290 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2293 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2294 va_start(ap, format);
2295 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2296 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2297 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2299 *log_msgptr = string_sprintf(
2300 "error in arguments to \"ratelimit\" condition: %s", buffer);
2307 /*************************************************
2308 * Handle rate limiting *
2309 *************************************************/
2311 /* Called by acl_check_condition() below to calculate the result
2312 of the ACL ratelimit condition.
2314 Note that the return value might be slightly unexpected: if the
2315 sender's rate is above the limit then the result is OK. This is
2316 similar to the dnslists condition, and is so that you can write
2317 ACL clauses like: defer ratelimit = 15 / 1h
2320 arg the option string for ratelimit=
2321 where ACL_WHERE_xxxx indicating which ACL this is
2322 log_msgptr for error messages
2324 Returns: OK - Sender's rate is above limit
2325 FAIL - Sender's rate is below limit
2326 DEFER - Problem opening ratelimit database
2327 ERROR - Syntax error in options.
2331 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2333 double limit, period, count;
2336 uschar *unique = NULL;
2338 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2339 BOOL noupdate = FALSE, badacl = FALSE;
2340 int mode = RATE_PER_WHAT;
2342 tree_node **anchor, *t;
2343 open_db dbblock, *dbm;
2345 dbdata_ratelimit *dbd;
2346 dbdata_ratelimit_unique *dbdb;
2349 /* Parse the first two options and record their values in expansion
2350 variables. These variables allow the configuration to have informative
2351 error messages based on rate limits obtained from a table lookup. */
2353 /* First is the maximum number of messages per period / maximum burst
2354 size, which must be greater than or equal to zero. Zero is useful for
2355 rate measurement as opposed to rate limiting. */
2357 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2358 if (sender_rate_limit == NULL)
2361 ss = NULL; /* compiler quietening */
2365 limit = Ustrtod(sender_rate_limit, &ss);
2366 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2367 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2368 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2370 if (limit < 0.0 || *ss != '\0')
2371 return ratelimit_error(log_msgptr,
2372 "\"%s\" is not a positive number", sender_rate_limit);
2374 /* Second is the rate measurement period / exponential smoothing time
2375 constant. This must be strictly greater than zero, because zero leads to
2376 run-time division errors. */
2378 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2379 if (sender_rate_period == NULL) period = -1.0;
2380 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2382 return ratelimit_error(log_msgptr,
2383 "\"%s\" is not a time value", sender_rate_period);
2385 /* By default we are counting one of something, but the per_rcpt,
2386 per_byte, and count options can change this. */
2390 /* Parse the other options. */
2392 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2395 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2396 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2397 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2398 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2399 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2400 else if (strcmpic(ss, US"per_conn") == 0)
2402 RATE_SET(mode, PER_CONN);
2403 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2406 else if (strcmpic(ss, US"per_mail") == 0)
2408 RATE_SET(mode, PER_MAIL);
2409 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2411 else if (strcmpic(ss, US"per_rcpt") == 0)
2413 /* If we are running in the RCPT ACL, then we'll count the recipients
2414 one by one, but if we are running when we have accumulated the whole
2415 list then we'll add them all in one batch. */
2416 if (where == ACL_WHERE_RCPT)
2417 RATE_SET(mode, PER_RCPT);
2418 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2419 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2420 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2421 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2423 else if (strcmpic(ss, US"per_byte") == 0)
2425 /* If we have not yet received the message data and there was no SIZE
2426 declaration on the MAIL comand, then it's safe to just use a value of
2427 zero and let the recorded rate decay as if nothing happened. */
2428 RATE_SET(mode, PER_MAIL);
2429 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2430 else count = message_size < 0 ? 0.0 : (double)message_size;
2432 else if (strcmpic(ss, US"per_addr") == 0)
2434 RATE_SET(mode, PER_RCPT);
2435 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2436 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2438 else if (strncmpic(ss, US"count=", 6) == 0)
2441 count = Ustrtod(ss+6, &e);
2442 if (count < 0.0 || *e != '\0')
2443 return ratelimit_error(log_msgptr,
2444 "\"%s\" is not a positive number", ss);
2446 else if (strncmpic(ss, US"unique=", 7) == 0)
2447 unique = string_copy(ss + 7);
2448 else if (key == NULL)
2449 key = string_copy(ss);
2451 key = string_sprintf("%s/%s", key, ss);
2454 /* Sanity check. When the badacl flag is set the update mode must either
2455 be readonly (which is the default if it is omitted) or, for backwards
2456 compatibility, a combination of noupdate and strict or leaky. */
2458 if (mode == RATE_PER_CLASH)
2459 return ratelimit_error(log_msgptr, "conflicting per_* options");
2460 if (leaky + strict + readonly > 1)
2461 return ratelimit_error(log_msgptr, "conflicting update modes");
2462 if (badacl && (leaky || strict) && !noupdate)
2463 return ratelimit_error(log_msgptr,
2464 "\"%s\" must not have /leaky or /strict option in %s ACL",
2465 ratelimit_option_string[mode], acl_wherenames[where]);
2467 /* Set the default values of any unset options. In readonly mode we
2468 perform the rate computation without any increment so that its value
2469 decays to eventually allow over-limit senders through. */
2471 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2472 if (badacl) readonly = TRUE;
2473 if (readonly) count = 0.0;
2474 if (!strict && !readonly) leaky = TRUE;
2475 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2477 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2478 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2479 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2480 are added to the key because they alter the meaning of the stored data. */
2483 key = (sender_host_address == NULL)? US"" : sender_host_address;
2485 key = string_sprintf("%s/%s/%s%s",
2487 ratelimit_option_string[mode],
2488 unique == NULL ? "" : "unique/",
2492 debug_printf("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2494 /* See if we have already computed the rate by looking in the relevant tree.
2495 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2496 pool so that they survive across resets. In readonly mode we only remember the
2497 result for the rest of this command in case a later command changes it. After
2498 this bit of logic the code is independent of the per_* mode. */
2500 old_pool = store_pool;
2503 anchor = &ratelimiters_cmd;
2506 anchor = &ratelimiters_conn;
2507 store_pool = POOL_PERM;
2511 case RATE_PER_ALLRCPTS:
2512 anchor = &ratelimiters_mail;
2517 anchor = &ratelimiters_cmd;
2520 anchor = NULL; /* silence an "unused" complaint */
2521 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2522 "internal ACL error: unknown ratelimit mode %d", mode);
2526 t = tree_search(*anchor, key);
2530 /* The following few lines duplicate some of the code below. */
2531 rc = (dbd->rate < limit)? FAIL : OK;
2532 store_pool = old_pool;
2533 sender_rate = string_sprintf("%.1f", dbd->rate);
2535 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2539 /* We aren't using a pre-computed rate, so get a previously recorded rate
2540 from the database, which will be updated and written back if required. */
2542 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2545 store_pool = old_pool;
2547 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2548 *log_msgptr = US"ratelimit database not available";
2551 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2554 gettimeofday(&tv, NULL);
2558 /* Locate the basic ratelimit block inside the DB data. */
2559 HDEBUG(D_acl) debug_printf("ratelimit found key in database\n");
2562 /* Forget the old Bloom filter if it is too old, so that we count each
2563 repeating event once per period. We don't simply clear and re-use the old
2564 filter because we want its size to change if the limit changes. Note that
2565 we keep the dbd pointer for copying the rate into the new data block. */
2567 if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period)
2569 HDEBUG(D_acl) debug_printf("ratelimit discarding old Bloom filter\n");
2575 if(unique != NULL && dbdb_size < sizeof(*dbdb))
2577 HDEBUG(D_acl) debug_printf("ratelimit discarding undersize Bloom filter\n");
2582 /* Allocate a new data block if the database lookup failed
2583 or the Bloom filter passed its age limit. */
2589 /* No Bloom filter. This basic ratelimit block is initialized below. */
2590 HDEBUG(D_acl) debug_printf("ratelimit creating new rate data block\n");
2591 dbdb_size = sizeof(*dbd);
2592 dbdb = store_get(dbdb_size);
2597 HDEBUG(D_acl) debug_printf("ratelimit creating new Bloom filter\n");
2599 /* See the long comment below for an explanation of the magic number 2.
2600 The filter has a minimum size in case the rate limit is very small;
2601 this is determined by the definition of dbdata_ratelimit_unique. */
2603 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2604 if (extra < 0) extra = 0;
2605 dbdb_size = sizeof(*dbdb) + extra;
2606 dbdb = store_get(dbdb_size);
2607 dbdb->bloom_epoch = tv.tv_sec;
2608 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2609 memset(dbdb->bloom, 0, dbdb->bloom_size);
2611 /* Preserve any basic ratelimit data (which is our longer-term memory)
2612 by copying it from the discarded block. */
2622 /* If we are counting unique events, find out if this event is new or not.
2623 If the client repeats the event during the current period then it should be
2624 counted. We skip this code in readonly mode for efficiency, because any
2625 changes to the filter will be discarded and because count is already set to
2628 if (unique != NULL && !readonly)
2630 /* We identify unique events using a Bloom filter. (You can find my
2631 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2632 With the per_addr option, an "event" is a recipient address, though the
2633 user can use the unique option to define their own events. We only count
2634 an event if we have not seen it before.
2636 We size the filter according to the rate limit, which (in leaky mode)
2637 is the limit on the population of the filter. We allow 16 bits of space
2638 per entry (see the construction code above) and we set (up to) 8 of them
2639 when inserting an element (see the loop below). The probability of a false
2640 positive (an event we have not seen before but which we fail to count) is
2644 allzero = exp(-numhash * pop / size)
2645 = exp(-0.5 * pop / limit)
2646 fpr = pow(1 - allzero, numhash)
2648 For senders at the limit the fpr is 0.06% or 1 in 1700
2649 and for senders at half the limit it is 0.0006% or 1 in 170000
2651 In strict mode the Bloom filter can fill up beyond the normal limit, in
2652 which case the false positive rate will rise. This means that the
2653 measured rate for very fast senders can bogusly drop off after a while.
2655 At twice the limit, the fpr is 2.5% or 1 in 40
2656 At four times the limit, it is 31% or 1 in 3.2
2658 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2659 decay below the limit, and if this is more than one then the Bloom filter
2660 will be discarded before the decay gets that far. The false positive rate
2661 at this threshold is 9.3% or 1 in 10.7. */
2664 unsigned n, hash, hinc;
2668 /* Instead of using eight independent hash values, we combine two values
2669 using the formula h1 + n * h2. This does not harm the Bloom filter's
2670 performance, and means the amount of hash we need is independent of the
2671 number of bits we set in the filter. */
2673 md5_start(&md5info);
2674 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2675 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2676 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2678 /* Scan the bits corresponding to this event. A zero bit means we have
2679 not seen it before. Ensure all bits are set to record this event. */
2681 HDEBUG(D_acl) debug_printf("ratelimit checking uniqueness of %s\n", unique);
2684 for (n = 0; n < 8; n++, hash += hinc)
2686 int bit = 1 << (hash % 8);
2687 int byte = (hash / 8) % dbdb->bloom_size;
2688 if ((dbdb->bloom[byte] & bit) == 0)
2690 dbdb->bloom[byte] |= bit;
2695 /* If this event has occurred before, do not count it. */
2699 HDEBUG(D_acl) debug_printf("ratelimit event found in Bloom filter\n");
2703 HDEBUG(D_acl) debug_printf("ratelimit event added to Bloom filter\n");
2706 /* If there was no previous ratelimit data block for this key, initialize
2707 the new one, otherwise update the block from the database. The initial rate
2708 is what would be computed by the code below for an infinite interval. */
2712 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's rate data\n");
2714 dbd->time_stamp = tv.tv_sec;
2715 dbd->time_usec = tv.tv_usec;
2720 /* The smoothed rate is computed using an exponentially weighted moving
2721 average adjusted for variable sampling intervals. The standard EWMA for
2722 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2723 where f() is the measured value and f'() is the smoothed value.
2725 Old data decays out of the smoothed value exponentially, such that data n
2726 samples old is multiplied by a^n. The exponential decay time constant p
2727 is defined such that data p samples old is multiplied by 1/e, which means
2728 that a = exp(-1/p). We can maintain the same time constant for a variable
2729 sampling interval i by using a = exp(-i/p).
2731 The rate we are measuring is messages per period, suitable for directly
2732 comparing with the limit. The average rate between now and the previous
2733 message is period / interval, which we feed into the EWMA as the sample.
2735 It turns out that the number of messages required for the smoothed rate
2736 to reach the limit when they are sent in a burst is equal to the limit.
2737 This can be seen by analysing the value of the smoothed rate after N
2738 messages sent at even intervals. Let k = (1 - a) * p/i
2740 rate_1 = (1 - a) * p/i + a * rate_0
2742 rate_2 = k + a * rate_1
2743 = k + a * k + a^2 * rate_0
2744 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2745 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2746 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2747 = rate_0 * a^N + p/i * (1 - a^N)
2749 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2751 rate_N = p/i + (rate_0 - p/i) * a^N
2752 a^N = (rate_N - p/i) / (rate_0 - p/i)
2753 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2754 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2756 Numerical analysis of the above equation, setting the computed rate to
2757 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2758 rates, p/i, the number of messages N = limit. So limit serves as both the
2759 maximum rate measured in messages per period, and the maximum number of
2760 messages that can be sent in a fast burst. */
2762 double this_time = (double)tv.tv_sec
2763 + (double)tv.tv_usec / 1000000.0;
2764 double prev_time = (double)dbd->time_stamp
2765 + (double)dbd->time_usec / 1000000.0;
2767 /* We must avoid division by zero, and deal gracefully with the clock going
2768 backwards. If we blunder ahead when time is in reverse then the computed
2769 rate will be bogus. To be safe we clamp interval to a very small number. */
2771 double interval = this_time - prev_time <= 0.0 ? 1e-9
2772 : this_time - prev_time;
2774 double i_over_p = interval / period;
2775 double a = exp(-i_over_p);
2777 /* Combine the instantaneous rate (period / interval) with the previous rate
2778 using the smoothing factor a. In order to measure sized events, multiply the
2779 instantaneous rate by the count of bytes or recipients etc. */
2781 dbd->time_stamp = tv.tv_sec;
2782 dbd->time_usec = tv.tv_usec;
2783 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2785 /* When events are very widely spaced the computed rate tends towards zero.
2786 Although this is accurate it turns out not to be useful for our purposes,
2787 especially when the first event after a long silence is the start of a spam
2788 run. A more useful model is that the rate for an isolated event should be the
2789 size of the event per the period size, ignoring the lack of events outside
2790 the current period and regardless of where the event falls in the period. So,
2791 if the interval was so long that the calculated rate is unhelpfully small, we
2792 re-intialize the rate. In the absence of higher-rate bursts, the condition
2793 below is true if the interval is greater than the period. */
2795 if (dbd->rate < count) dbd->rate = count;
2798 /* Clients sending at the limit are considered to be over the limit.
2799 This matters for edge cases such as a limit of zero, when the client
2800 should be completely blocked. */
2802 rc = (dbd->rate < limit)? FAIL : OK;
2804 /* Update the state if the rate is low or if we are being strict. If we
2805 are in leaky mode and the sender's rate is too high, we do not update
2806 the recorded rate in order to avoid an over-aggressive sender's retry
2807 rate preventing them from getting any email through. If readonly is set,
2808 neither leaky nor strict are set, so we do not do any updates. */
2810 if ((rc == FAIL && leaky) || strict)
2812 dbfn_write(dbm, key, dbdb, dbdb_size);
2813 HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
2817 HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
2818 readonly? "readonly mode" : "over the limit, but leaky");
2823 /* Store the result in the tree for future reference. */
2825 t = store_get(sizeof(tree_node) + Ustrlen(key));
2827 Ustrcpy(t->name, key);
2828 (void)tree_insertnode(anchor, t);
2830 /* We create the formatted version of the sender's rate very late in
2831 order to ensure that it is done using the correct storage pool. */
2833 store_pool = old_pool;
2834 sender_rate = string_sprintf("%.1f", dbd->rate);
2837 debug_printf("ratelimit computed rate %s\n", sender_rate);
2844 /*************************************************
2845 * The udpsend ACL modifier *
2846 *************************************************/
2848 /* Called by acl_check_condition() below.
2851 arg the option string for udpsend=
2852 log_msgptr for error messages
2854 Returns: OK - Completed.
2855 DEFER - Problem with DNS lookup.
2856 ERROR - Syntax error in options.
2860 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2872 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2873 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2875 if (hostname == NULL)
2877 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2880 if (portstr == NULL)
2882 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2887 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2890 portnum = Ustrtol(portstr, &portend, 10);
2891 if (*portend != '\0')
2893 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2897 /* Make a single-item host list. */
2898 h = store_get(sizeof(host_item));
2899 memset(h, 0, sizeof(host_item));
2904 if (string_is_ip_address(hostname, NULL))
2905 h->address = hostname, r = HOST_FOUND;
2907 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2908 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2910 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2915 debug_printf("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2917 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2919 if (r < 0) goto defer;
2921 r = send(s, arg, len, 0);
2924 errstr = US strerror(errno);
2932 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2937 debug_printf("udpsend %d bytes\n", r);
2942 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2948 /*************************************************
2949 * Handle conditions/modifiers on an ACL item *
2950 *************************************************/
2952 /* Called from acl_check() below.
2956 cb ACL condition block - if NULL, result is OK
2957 where where called from
2958 addr the address being checked for RCPT, or NULL
2959 level the nesting level
2960 epp pointer to pass back TRUE if "endpass" encountered
2961 (applies only to "accept" and "discard")
2962 user_msgptr user message pointer
2963 log_msgptr log message pointer
2964 basic_errno pointer to where to put verify error
2966 Returns: OK - all conditions are met
2967 DISCARD - an "acl" condition returned DISCARD - only allowed
2968 for "accept" or "discard" verbs
2969 FAIL - at least one condition fails
2970 FAIL_DROP - an "acl" condition returned FAIL_DROP
2971 DEFER - can't tell at the moment (typically, lookup defer,
2972 but can be temporary callout problem)
2973 ERROR - ERROR from nested ACL or expansion failure or other
2978 acl_check_condition(int verb, acl_condition_block *cb, int where,
2979 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2980 uschar **log_msgptr, int *basic_errno)
2982 uschar *user_message = NULL;
2983 uschar *log_message = NULL;
2984 uschar *debug_tag = NULL;
2985 uschar *debug_opts = NULL;
2987 #ifdef WITH_CONTENT_SCAN
2991 for (; cb != NULL; cb = cb->next)
2996 /* The message and log_message items set up messages to be used in
2997 case of rejection. They are expanded later. */
2999 if (cb->type == ACLC_MESSAGE)
3001 HDEBUG(D_acl) debug_printf(" message: %s\n", cb->arg);
3002 user_message = cb->arg;
3006 if (cb->type == ACLC_LOG_MESSAGE)
3008 HDEBUG(D_acl) debug_printf("l_message: %s\n", cb->arg);
3009 log_message = cb->arg;
3013 /* The endpass "condition" just sets a flag to show it occurred. This is
3014 checked at compile time to be on an "accept" or "discard" item. */
3016 if (cb->type == ACLC_ENDPASS)
3022 /* For other conditions and modifiers, the argument is expanded now for some
3023 of them, but not for all, because expansion happens down in some lower level
3024 checking functions in some cases. */
3026 if (cond_expand_at_top[cb->type])
3028 arg = expand_string(cb->arg);
3031 if (expand_string_forcedfail) continue;
3032 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
3033 cb->arg, expand_string_message);
3034 return search_find_defer? DEFER : ERROR;
3039 /* Show condition, and expanded condition if it's different */
3044 debug_printf("check %s%s %n",
3045 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
3046 conditions[cb->type], &lhswidth);
3048 if (cb->type == ACLC_SET)
3050 debug_printf("acl_%s ", cb->u.varname);
3051 lhswidth += 5 + Ustrlen(cb->u.varname);
3054 debug_printf("= %s\n", cb->arg);
3057 debug_printf("%.*s= %s\n", lhswidth,
3061 /* Check that this condition makes sense at this time */
3063 if ((cond_forbids[cb->type] & (1 << where)) != 0)
3065 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
3066 cond_modifiers[cb->type]? "use" : "test",
3067 conditions[cb->type], acl_wherenames[where]);
3071 /* Run the appropriate test for each condition, or take the appropriate
3072 action for the remaining modifiers. */
3076 case ACLC_ADD_HEADER:
3080 /* A nested ACL that returns "discard" makes sense only for an "accept" or
3084 rc = acl_check_wargs(where, addr, arg, level+1, user_msgptr, log_msgptr);
3085 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
3087 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
3088 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
3094 case ACLC_AUTHENTICATED:
3095 rc = (sender_host_authenticated == NULL)? FAIL :
3096 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
3100 #ifdef EXPERIMENTAL_BRIGHTMAIL
3101 case ACLC_BMI_OPTIN:
3103 int old_pool = store_pool;
3104 store_pool = POOL_PERM;
3105 bmi_current_optin = string_copy(arg);
3106 store_pool = old_pool;
3111 case ACLC_CONDITION:
3112 /* The true/false parsing here should be kept in sync with that used in
3113 expand.c when dealing with ECOND_BOOL so that we don't have too many
3114 different definitions of what can be a boolean. */
3116 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
3117 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
3118 rc = (Uatoi(arg) == 0)? FAIL : OK;
3120 rc = (strcmpic(arg, US"no") == 0 ||
3121 strcmpic(arg, US"false") == 0)? FAIL :
3122 (strcmpic(arg, US"yes") == 0 ||
3123 strcmpic(arg, US"true") == 0)? OK : DEFER;
3125 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3128 case ACLC_CONTINUE: /* Always succeeds */
3133 const uschar *p = NULL;
3134 control_type = decode_control(arg, &p, where, log_msgptr);
3136 /* Check if this control makes sense at this time */
3138 if ((control_forbids[control_type] & (1 << where)) != 0)
3140 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3141 controls[control_type], acl_wherenames[where]);
3145 switch(control_type)
3147 case CONTROL_AUTH_UNADVERTISED:
3148 allow_auth_unadvertised = TRUE;
3151 #ifdef EXPERIMENTAL_BRIGHTMAIL
3152 case CONTROL_BMI_RUN:
3157 #ifndef DISABLE_DKIM
3158 case CONTROL_DKIM_VERIFY:
3159 dkim_disable_verify = TRUE;
3160 #ifdef EXPERIMENTAL_DMARC
3161 /* Since DKIM was blocked, skip DMARC too */
3162 dmarc_disable_verify = TRUE;
3163 dmarc_enable_forensic = FALSE;
3168 #ifdef EXPERIMENTAL_DMARC
3169 case CONTROL_DMARC_VERIFY:
3170 dmarc_disable_verify = TRUE;
3173 case CONTROL_DMARC_FORENSIC:
3174 dmarc_enable_forensic = TRUE;
3181 int fd, af, level, optname, value;
3182 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3183 a socket; we can accept that, we'll just debug-log failures anyway. */
3184 fd = fileno(smtp_in);
3185 af = ip_get_address_family(fd);
3189 debug_printf("smtp input is probably not a socket [%s], not setting DSCP\n",
3193 if (dscp_lookup(p+1, af, &level, &optname, &value))
3195 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3197 HDEBUG(D_acl) debug_printf("failed to set input DSCP[%s]: %s\n",
3198 p+1, strerror(errno));
3202 HDEBUG(D_acl) debug_printf("set input DSCP to \"%s\"\n", p+1);
3207 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3213 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3221 case CONTROL_CASEFUL_LOCAL_PART:
3222 deliver_localpart = addr->cc_local_part;
3225 case CONTROL_CASELOWER_LOCAL_PART:
3226 deliver_localpart = addr->lc_local_part;
3229 case CONTROL_ENFORCE_SYNC:
3230 smtp_enforce_sync = TRUE;
3233 case CONTROL_NO_ENFORCE_SYNC:
3234 smtp_enforce_sync = FALSE;
3237 #ifdef WITH_CONTENT_SCAN
3238 case CONTROL_NO_MBOX_UNSPOOL:
3239 no_mbox_unspool = TRUE;
3243 case CONTROL_NO_MULTILINE:
3244 no_multiline_responses = TRUE;
3247 case CONTROL_NO_PIPELINING:
3248 pipelining_enable = FALSE;
3251 case CONTROL_NO_DELAY_FLUSH:
3252 disable_delay_flush = TRUE;
3255 case CONTROL_NO_CALLOUT_FLUSH:
3256 disable_callout_flush = TRUE;
3259 case CONTROL_FAKEREJECT:
3260 cancel_cutthrough_connection("fakereject");
3261 case CONTROL_FAKEDEFER:
3262 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3265 const uschar *pp = p + 1;
3266 while (*pp != 0) pp++;
3267 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3272 /* Explicitly reset to default string */
3273 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).";
3277 case CONTROL_FREEZE:
3278 deliver_freeze = TRUE;
3279 deliver_frozen_at = time(NULL);
3280 freeze_tell = freeze_tell_config; /* Reset to configured value */
3281 if (Ustrncmp(p, "/no_tell", 8) == 0)
3288 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3291 cancel_cutthrough_connection("item frozen");
3294 case CONTROL_QUEUE_ONLY:
3295 queue_only_policy = TRUE;
3296 cancel_cutthrough_connection("queueing forced");
3299 case CONTROL_SUBMISSION:
3300 originator_name = US"";
3301 submission_mode = TRUE;
3304 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3307 active_local_sender_retain = TRUE;
3308 active_local_from_check = FALSE;
3310 else if (Ustrncmp(p, "/domain=", 8) == 0)
3312 const uschar *pp = p + 8;
3313 while (*pp != 0 && *pp != '/') pp++;
3314 submission_domain = string_copyn(p+8, pp-p-8);
3317 /* The name= option must be last, because it swallows the rest of
3319 else if (Ustrncmp(p, "/name=", 6) == 0)
3321 const uschar *pp = p + 6;
3322 while (*pp != 0) pp++;
3323 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3324 big_buffer, big_buffer_size));
3331 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3339 if (Ustrncmp(p, "/tag=", 5) == 0)
3341 const uschar *pp = p + 5;
3342 while (*pp != '\0' && *pp != '/') pp++;
3343 debug_tag = string_copyn(p+5, pp-p-5);
3346 else if (Ustrncmp(p, "/opts=", 6) == 0)
3348 const uschar *pp = p + 6;
3349 while (*pp != '\0' && *pp != '/') pp++;
3350 debug_opts = string_copyn(p+6, pp-p-6);
3354 debug_logging_activate(debug_tag, debug_opts);
3357 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3358 suppress_local_fixups = TRUE;
3361 case CONTROL_CUTTHROUGH_DELIVERY:
3363 /* Too hard to think about for now. We might in future cutthrough
3364 the case where both sides handle prdr and this-node prdr acl
3366 *log_msgptr = string_sprintf("PRDR on %s reception\n", arg);
3370 *log_msgptr = US"frozen";
3371 else if (queue_only_policy)
3372 *log_msgptr = US"queue-only";
3373 else if (fake_response == FAIL)
3374 *log_msgptr = US"fakereject";
3377 if (rcpt_count == 1) cutthrough.delivery = TRUE;
3380 *log_msgptr = string_sprintf("\"control=%s\" on %s item",
3388 #ifdef EXPERIMENTAL_DCC
3391 /* Seperate the regular expression and any optional parameters. */
3392 const uschar * list = arg;
3393 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3394 /* Run the dcc backend. */
3395 rc = dcc_process(&ss);
3396 /* Modify return code based upon the existance of options. */
3397 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
3399 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3401 /* FAIL so that the message is passed to the next ACL */
3409 #ifdef WITH_CONTENT_SCAN
3411 rc = mime_decode(&arg);
3417 int delay = readconf_readtime(arg, 0, FALSE);
3420 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3421 "modifier: \"%s\" is not a time value", arg);
3426 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
3431 debug_printf("delay skipped in -bh checking mode\n");
3434 /* It appears to be impossible to detect that a TCP/IP connection has
3435 gone away without reading from it. This means that we cannot shorten
3436 the delay below if the client goes away, because we cannot discover
3437 that the client has closed its end of the connection. (The connection
3438 is actually in a half-closed state, waiting for the server to close its
3439 end.) It would be nice to be able to detect this state, so that the
3440 Exim process is not held up unnecessarily. However, it seems that we
3441 can't. The poll() function does not do the right thing, and in any case
3442 it is not always available.
3444 NOTE 1: If ever this state of affairs changes, remember that we may be
3445 dealing with stdin/stdout here, in addition to TCP/IP connections.
3446 Also, delays may be specified for non-SMTP input, where smtp_out and
3447 smtp_in will be NULL. Whatever is done must work in all cases.
3449 NOTE 2: The added feature of flushing the output before a delay must
3450 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3455 if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush();
3456 while (delay > 0) delay = sleep(delay);
3462 #ifdef WITH_OLD_DEMIME
3468 #ifndef DISABLE_DKIM
3469 case ACLC_DKIM_SIGNER:
3470 if (dkim_cur_signer != NULL)
3471 rc = match_isinlist(dkim_cur_signer,
3472 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3477 case ACLC_DKIM_STATUS:
3478 rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS),
3479 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3483 #ifdef EXPERIMENTAL_DMARC
3484 case ACLC_DMARC_STATUS:
3485 if (!dmarc_has_been_checked)
3487 dmarc_has_been_checked = TRUE;
3488 /* used long way of dmarc_exim_expand_query() in case we need more
3489 * view into the process in the future. */
3490 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3491 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3496 rc = verify_check_dnsbl(&arg);
3500 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3501 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3504 /* The value in tls_cipher is the full cipher name, for example,
3505 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3506 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3507 what may in practice come out of the SSL library - which at the time of
3508 writing is poorly documented. */
3510 case ACLC_ENCRYPTED:
3511 if (tls_in.cipher == NULL) rc = FAIL; else
3513 uschar *endcipher = NULL;
3514 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3515 if (cipher == NULL) cipher = tls_in.cipher; else
3517 endcipher = Ustrchr(++cipher, ':');
3518 if (endcipher != NULL) *endcipher = 0;
3520 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3521 if (endcipher != NULL) *endcipher = ':';
3525 /* Use verify_check_this_host() instead of verify_check_host() so that
3526 we can pass over &host_data to catch any looked up data. Once it has been
3527 set, it retains its value so that it's still there if another ACL verb
3528 comes through here and uses the cache. However, we must put it into
3529 permanent store in case it is also expected to be used in a subsequent
3530 message in the same SMTP connection. */
3533 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3534 (sender_host_address == NULL)? US"" : sender_host_address,
3536 if (host_data != NULL) host_data = string_copy_malloc(host_data);
3539 case ACLC_LOCAL_PARTS:
3540 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3541 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3542 CUSS &deliver_localpart_data);
3545 case ACLC_LOG_REJECT_TARGET:
3549 const uschar *s = arg;
3551 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
3554 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3555 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3556 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3559 logbits |= LOG_MAIN|LOG_REJECT;
3560 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3561 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3564 log_reject_target = logbits;
3571 const uschar *s = arg;
3577 if (Ustrncmp(s, "main", 4) == 0)
3578 { logbits |= LOG_MAIN; s += 4; }
3579 else if (Ustrncmp(s, "panic", 5) == 0)
3580 { logbits |= LOG_PANIC; s += 5; }
3581 else if (Ustrncmp(s, "reject", 6) == 0)
3582 { logbits |= LOG_REJECT; s += 6; }
3585 logbits = LOG_MAIN|LOG_PANIC;
3586 s = string_sprintf(":unknown log name in \"%s\" in "
3587 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3593 while (isspace(*s)) s++;
3596 if (logbits == 0) logbits = LOG_MAIN;
3597 log_write(0, logbits, "%s", string_printing(s));
3601 #ifdef WITH_CONTENT_SCAN
3602 case ACLC_MALWARE: /* Run the malware backend. */
3604 /* Separate the regular expression and any optional parameters. */
3605 const uschar * list = arg;
3606 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3608 BOOL defer_ok = FALSE;
3611 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3612 if (strcmpic(opt, US"defer_ok") == 0)
3614 else if ( strncmpic(opt, US"tmo=", 4) == 0
3615 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3618 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3622 rc = malware(ss, timeout);
3623 if (rc == DEFER && defer_ok)
3624 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3628 case ACLC_MIME_REGEX:
3629 rc = mime_regex(&arg);
3633 case ACLC_RATELIMIT:
3634 rc = acl_ratelimit(arg, where, log_msgptr);
3637 case ACLC_RECIPIENTS:
3638 rc = match_address_list((const uschar *)addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3639 CUSS &recipient_data);
3642 #ifdef WITH_CONTENT_SCAN
3648 case ACLC_REMOVE_HEADER:
3649 setup_remove_header(arg);
3652 case ACLC_SENDER_DOMAINS:
3655 sdomain = Ustrrchr(sender_address, '@');
3656 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
3657 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3658 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3663 rc = match_address_list((const uschar *)sender_address, TRUE, TRUE, &arg,
3664 sender_address_cache, -1, 0, CUSS &sender_data);
3667 /* Connection variables must persist forever */
3671 int old_pool = store_pool;
3672 if (cb->u.varname[0] == 'c') store_pool = POOL_PERM;
3673 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3674 store_pool = old_pool;
3678 #ifdef WITH_CONTENT_SCAN
3681 /* Seperate the regular expression and any optional parameters. */
3682 const uschar * list = arg;
3683 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3684 /* Run the spam backend. */
3685 rc = spam(CUSS &ss);
3686 /* Modify return code based upon the existance of options. */
3687 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
3689 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3691 /* FAIL so that the message is passed to the next ACL */
3699 #ifdef EXPERIMENTAL_SPF
3701 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3703 case ACLC_SPF_GUESS:
3704 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3709 rc = acl_udpsend(arg, log_msgptr);
3712 /* If the verb is WARN, discard any user message from verification, because
3713 such messages are SMTP responses, not header additions. The latter come
3714 only from explicit "message" modifiers. However, put the user message into
3715 $acl_verify_message so it can be used in subsequent conditions or modifiers
3716 (until something changes it). */
3719 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3720 acl_verify_message = *user_msgptr;
3721 if (verb == ACL_WARN) *user_msgptr = NULL;
3725 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3726 "condition %d", cb->type);
3730 /* If a condition was negated, invert OK/FAIL. */
3732 if (!cond_modifiers[cb->type] && cb->u.negated)
3734 if (rc == OK) rc = FAIL;
3735 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3738 if (rc != OK) break; /* Conditions loop */
3742 /* If the result is the one for which "message" and/or "log_message" are used,
3743 handle the values of these modifiers. If there isn't a log message set, we make
3744 it the same as the user message.
3746 "message" is a user message that will be included in an SMTP response. Unless
3747 it is empty, it overrides any previously set user message.
3749 "log_message" is a non-user message, and it adds to any existing non-user
3750 message that is already set.
3752 Most verbs have but a single return for which the messages are relevant, but
3753 for "discard", it's useful to have the log message both when it succeeds and
3754 when it fails. For "accept", the message is used in the OK case if there is no
3755 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3758 if (*epp && rc == OK) user_message = NULL;
3760 if (((1<<rc) & msgcond[verb]) != 0)
3763 uschar *old_user_msgptr = *user_msgptr;
3764 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3766 /* If the verb is "warn", messages generated by conditions (verification or
3767 nested ACLs) are always discarded. This also happens for acceptance verbs
3768 when they actually do accept. Only messages specified at this level are used.
3769 However, the value of an existing message is available in $acl_verify_message
3770 during expansions. */
3772 if (verb == ACL_WARN ||
3773 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3774 *log_msgptr = *user_msgptr = NULL;
3776 if (user_message != NULL)
3778 acl_verify_message = old_user_msgptr;
3779 expmessage = expand_string(user_message);
3780 if (expmessage == NULL)
3782 if (!expand_string_forcedfail)
3783 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3784 user_message, expand_string_message);
3786 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3789 if (log_message != NULL)
3791 acl_verify_message = old_log_msgptr;
3792 expmessage = expand_string(log_message);
3793 if (expmessage == NULL)
3795 if (!expand_string_forcedfail)
3796 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3797 log_message, expand_string_message);
3799 else if (expmessage[0] != 0)
3801 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3802 string_sprintf("%s: %s", expmessage, *log_msgptr);
3806 /* If no log message, default it to the user message */
3808 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3811 acl_verify_message = NULL;
3819 /*************************************************
3820 * Get line from a literal ACL *
3821 *************************************************/
3823 /* This function is passed to acl_read() in order to extract individual lines
3824 of a literal ACL, which we access via static pointers. We can destroy the
3825 contents because this is called only once (the compiled ACL is remembered).
3827 This code is intended to treat the data in the same way as lines in the main
3828 Exim configuration file. That is:
3830 . Leading spaces are ignored.
3832 . A \ at the end of a line is a continuation - trailing spaces after the \
3833 are permitted (this is because I don't believe in making invisible things
3834 significant). Leading spaces on the continued part of a line are ignored.
3836 . Physical lines starting (significantly) with # are totally ignored, and
3837 may appear within a sequence of backslash-continued lines.
3839 . Blank lines are ignored, but will end a sequence of continuations.
3842 Returns: a pointer to the next line
3846 static uschar *acl_text; /* Current pointer in the text */
3847 static uschar *acl_text_end; /* Points one past the terminating '0' */
3855 /* This loop handles leading blank lines and comments. */
3859 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3860 if (*acl_text == 0) return NULL; /* No more data */
3861 yield = acl_text; /* Potential data line */
3863 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3865 /* If we hit the end before a newline, we have the whole logical line. If
3866 it's a comment, there's no more data to be given. Otherwise, yield it. */
3868 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3870 /* After reaching a newline, end this loop if the physical line does not
3871 start with '#'. If it does, it's a comment, and the loop continues. */
3873 if (*yield != '#') break;
3876 /* This loop handles continuations. We know we have some real data, ending in
3877 newline. See if there is a continuation marker at the end (ignoring trailing
3878 white space). We know that *yield is not white space, so no need to test for
3879 cont > yield in the backwards scanning loop. */
3884 for (cont = acl_text - 1; isspace(*cont); cont--);
3886 /* If no continuation follows, we are done. Mark the end of the line and
3895 /* We have encountered a continuation. Skip over whitespace at the start of
3896 the next line, and indeed the whole of the next line or lines if they are
3901 while (*(++acl_text) == ' ' || *acl_text == '\t');
3902 if (*acl_text != '#') break;
3903 while (*(++acl_text) != 0 && *acl_text != '\n');
3906 /* We have the start of a continuation line. Move all the rest of the data
3907 to join onto the previous line, and then find its end. If the end is not a
3908 newline, we are done. Otherwise loop to look for another continuation. */
3910 memmove(cont, acl_text, acl_text_end - acl_text);
3911 acl_text_end -= acl_text - cont;
3913 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3914 if (*acl_text == 0) return yield;
3917 /* Control does not reach here */
3924 /*************************************************
3925 * Check access using an ACL *
3926 *************************************************/
3928 /* This function is called from address_check. It may recurse via
3929 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3930 passed as a string which is expanded. A forced failure implies no access check
3931 is required. If the result is a single word, it is taken as the name of an ACL
3932 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3933 text, complete with newlines, and parsed as such. In both cases, the ACL check
3934 is then run. This function uses an auxiliary function for acl_read() to call
3935 for reading individual lines of a literal ACL. This is acl_getline(), which
3936 appears immediately above.
3939 where where called from
3940 addr address item when called from RCPT; otherwise NULL
3941 s the input string; NULL is the same as an empty ACL => DENY
3942 level the nesting level
3943 user_msgptr where to put a user error (for SMTP response)
3944 log_msgptr where to put a logging message (not for SMTP response)
3946 Returns: OK access is granted
3947 DISCARD access is apparently granted...
3948 FAIL access is denied
3949 FAIL_DROP access is denied; drop the connection
3950 DEFER can't tell at the moment
3955 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3956 uschar **user_msgptr, uschar **log_msgptr)
3959 acl_block *acl = NULL;
3960 uschar *acl_name = US"inline ACL";
3963 /* Catch configuration loops */
3967 *log_msgptr = US"ACL nested too deep: possible loop";
3973 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3977 /* At top level, we expand the incoming string. At lower levels, it has already
3978 been expanded as part of condition processing. */
3982 ss = expand_string(s);
3985 if (expand_string_forcedfail) return OK;
3986 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3987 expand_string_message);
3993 while (isspace(*ss))ss++;
3995 /* If we can't find a named ACL, the default is to parse it as an inline one.
3996 (Unless it begins with a slash; non-existent files give rise to an error.) */
4000 /* Handle the case of a string that does not contain any spaces. Look for a
4001 named ACL among those read from the configuration, or a previously read file.
4002 It is possible that the pointer to the ACL is NULL if the configuration
4003 contains a name with no data. If not found, and the text begins with '/',
4004 read an ACL from a file, and save it so it can be re-used. */
4006 if (Ustrchr(ss, ' ') == NULL)
4008 tree_node *t = tree_search(acl_anchor, ss);
4011 acl = (acl_block *)(t->data.ptr);
4014 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
4017 acl_name = string_sprintf("ACL \"%s\"", ss);
4018 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
4021 else if (*ss == '/')
4023 struct stat statbuf;
4024 fd = Uopen(ss, O_RDONLY, 0);
4027 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4032 if (fstat(fd, &statbuf) != 0)
4034 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4039 acl_text = store_get(statbuf.st_size + 1);
4040 acl_text_end = acl_text + statbuf.st_size + 1;
4042 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4044 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4045 ss, strerror(errno));
4048 acl_text[statbuf.st_size] = 0;
4051 acl_name = string_sprintf("ACL \"%s\"", ss);
4052 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
4056 /* Parse an ACL that is still in text form. If it came from a file, remember it
4057 in the ACL tree, having read it into the POOL_PERM store pool so that it
4058 persists between multiple messages. */
4062 int old_pool = store_pool;
4063 if (fd >= 0) store_pool = POOL_PERM;
4064 acl = acl_read(acl_getline, log_msgptr);
4065 store_pool = old_pool;
4066 if (acl == NULL && *log_msgptr != NULL) return ERROR;
4069 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
4070 Ustrcpy(t->name, ss);
4072 (void)tree_insertnode(&acl_anchor, t);
4076 /* Now we have an ACL to use. It's possible it may be NULL. */
4081 int basic_errno = 0;
4082 BOOL endpass_seen = FALSE;
4083 BOOL acl_quit_check = level == 0
4084 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4086 *log_msgptr = *user_msgptr = NULL;
4087 acl_temp_details = FALSE;
4089 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
4091 /* Clear out any search error message from a previous check before testing
4094 search_error_message = NULL;
4095 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
4096 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4098 /* Handle special returns: DEFER causes a return except on a WARN verb;
4099 ERROR always causes a return. */
4104 HDEBUG(D_acl) debug_printf("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
4105 if (basic_errno != ERRNO_CALLOUTDEFER)
4107 if (search_error_message != NULL && *search_error_message != 0)
4108 *log_msgptr = search_error_message;
4109 if (smtp_return_error_details) acl_temp_details = TRUE;
4113 acl_temp_details = TRUE;
4115 if (acl->verb != ACL_WARN) return DEFER;
4118 default: /* Paranoia */
4120 HDEBUG(D_acl) debug_printf("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
4124 HDEBUG(D_acl) debug_printf("%s: condition test succeeded in %s\n",
4125 verbs[acl->verb], acl_name);
4129 HDEBUG(D_acl) debug_printf("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
4132 /* DISCARD and DROP can happen only from a nested ACL condition, and
4133 DISCARD can happen only for an "accept" or "discard" verb. */
4136 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\" in %s\n",
4137 verbs[acl->verb], acl_name);
4141 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\" in %s\n",
4142 verbs[acl->verb], acl_name);
4146 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4147 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4148 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4153 if (cond == OK || cond == DISCARD)
4155 HDEBUG(D_acl) debug_printf("end of %s: ACCEPT\n", acl_name);
4160 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
4168 HDEBUG(D_acl) debug_printf("end of %s: DEFER\n", acl_name);
4169 if (acl_quit_check) goto badquit;
4170 acl_temp_details = TRUE;
4178 HDEBUG(D_acl) debug_printf("end of %s: DENY\n", acl_name);
4179 if (acl_quit_check) goto badquit;
4185 if (cond == OK || cond == DISCARD)
4187 HDEBUG(D_acl) debug_printf("end of %s: DISCARD\n", acl_name);
4188 if (acl_quit_check) goto badquit;
4193 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
4201 HDEBUG(D_acl) debug_printf("end of %s: DROP\n", acl_name);
4202 if (acl_quit_check) goto badquit;
4210 HDEBUG(D_acl) debug_printf("end of %s: not OK\n", acl_name);
4211 if (acl_quit_check) goto badquit;
4218 acl_warn(where, *user_msgptr, *log_msgptr);
4219 else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
4220 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4221 "condition test deferred%s%s", host_and_ident(TRUE),
4222 (*log_msgptr == NULL)? US"" : US": ",
4223 (*log_msgptr == NULL)? US"" : *log_msgptr);
4224 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4228 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4233 /* Pass to the next ACL item */
4238 /* We have reached the end of the ACL. This is an implicit DENY. */
4240 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
4244 *log_msgptr = string_sprintf("QUIT or not-QUIT teplevel ACL may not fail "
4245 "('%s' verb used incorrectly)", verbs[acl->verb]);
4252 /* Same args as acl_check_internal() above, but the string s is
4253 the name of an ACL followed optionally by up to 9 space-separated arguments.
4254 The name and args are separately expanded. Args go into $acl_arg globals. */
4256 acl_check_wargs(int where, address_item *addr, const uschar *s, int level,
4257 uschar **user_msgptr, uschar **log_msgptr)
4260 uschar * tmp_arg[9]; /* must match acl_arg[] */
4261 uschar * sav_arg[9]; /* must match acl_arg[] */
4267 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4270 for (i = 0; i < 9; i++)
4272 while (*s && isspace(*s)) s++;
4274 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4281 sav_narg = acl_narg;
4283 for (i = 0; i < acl_narg; i++)
4285 sav_arg[i] = acl_arg[i];
4286 acl_arg[i] = tmp_arg[i];
4290 sav_arg[i] = acl_arg[i];
4291 acl_arg[i++] = NULL;
4294 ret = acl_check_internal(where, addr, name, level, user_msgptr, log_msgptr);
4296 acl_narg = sav_narg;
4297 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4301 if (expand_string_forcedfail) return ERROR;
4302 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4303 tmp, expand_string_message);
4304 return search_find_defer?DEFER:ERROR;
4309 /*************************************************
4310 * Check access using an ACL *
4311 *************************************************/
4313 /* Alternate interface for ACL, used by expansions */
4315 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4318 address_item *addr = NULL;
4320 *user_msgptr = *log_msgptr = NULL;
4321 sender_verified_failed = NULL;
4322 ratelimiters_cmd = NULL;
4323 log_reject_target = LOG_MAIN|LOG_REJECT;
4325 if (where == ACL_WHERE_RCPT)
4327 adb = address_defaults;
4329 addr->address = expand_string(US"$local_part@$domain");
4330 addr->domain = deliver_domain;
4331 addr->local_part = deliver_localpart;
4332 addr->cc_local_part = deliver_localpart;
4333 addr->lc_local_part = deliver_localpart;
4336 return acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
4341 /* This is the external interface for ACL checks. It sets up an address and the
4342 expansions for $domain and $local_part when called after RCPT, then calls
4343 acl_check_internal() to do the actual work.
4346 where ACL_WHERE_xxxx indicating where called from
4347 recipient RCPT address for RCPT check, else NULL
4348 s the input string; NULL is the same as an empty ACL => DENY
4349 user_msgptr where to put a user error (for SMTP response)
4350 log_msgptr where to put a logging message (not for SMTP response)
4352 Returns: OK access is granted by an ACCEPT verb
4353 DISCARD access is granted by a DISCARD verb
4354 FAIL access is denied
4355 FAIL_DROP access is denied; drop the connection
4356 DEFER can't tell at the moment
4359 int acl_where = ACL_WHERE_UNKNOWN;
4362 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4363 uschar **log_msgptr)
4367 address_item *addr = NULL;
4369 *user_msgptr = *log_msgptr = NULL;
4370 sender_verified_failed = NULL;
4371 ratelimiters_cmd = NULL;
4372 log_reject_target = LOG_MAIN|LOG_REJECT;
4374 #ifndef DISABLE_PRDR
4375 if (where == ACL_WHERE_RCPT || where == ACL_WHERE_PRDR)
4377 if (where == ACL_WHERE_RCPT)
4380 adb = address_defaults;
4382 addr->address = recipient;
4383 if (deliver_split_address(addr) == DEFER)
4385 *log_msgptr = US"defer in percent_hack_domains check";
4388 #ifdef EXPERIMENTAL_INTERNATIONAL
4389 addr->p.utf8 = message_smtputf8;
4391 deliver_domain = addr->domain;
4392 deliver_localpart = addr->local_part;
4396 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
4397 acl_where = ACL_WHERE_UNKNOWN;
4399 /* Cutthrough - if requested,
4400 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4401 and rcpt acl returned accept,
4402 and first recipient (cancel on any subsequents)
4403 open one now and run it up to RCPT acceptance.
4404 A failed verify should cancel cutthrough request.
4406 Initial implementation: dual-write to spool.
4407 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4409 Cease cutthrough copy on rxd final dot; do not send one.
4411 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4413 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4414 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4415 If temp-reject, close the conn (and keep the spooled copy).
4416 If conn-failure, no action (and keep the spooled copy).
4420 case ACL_WHERE_RCPT:
4421 #ifndef DISABLE_PRDR
4422 case ACL_WHERE_PRDR:
4424 if (rc == OK && cutthrough.delivery && rcpt_count > cutthrough.nrcpt)
4425 open_cutthrough_connection(addr);
4428 case ACL_WHERE_PREDATA:
4430 cutthrough_predata();
4432 cancel_cutthrough_connection("predata acl not ok");
4435 case ACL_WHERE_QUIT:
4436 case ACL_WHERE_NOTQUIT:
4437 cancel_cutthrough_connection("quit or notquit");
4444 deliver_domain = deliver_localpart = deliver_address_data =
4445 sender_address_data = NULL;
4447 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4448 ACL, which is really in the middle of an SMTP command. */
4452 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4454 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4455 "ACL", acl_wherenames[where]);
4461 /* A DROP response is not permitted from MAILAUTH */
4463 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4465 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4466 "ACL", acl_wherenames[where]);
4470 /* Before giving a response, take a look at the length of any user message, and
4471 split it up into multiple lines if possible. */
4473 *user_msgptr = string_split_message(*user_msgptr);
4474 if (fake_response != OK)
4475 fake_response_text = string_split_message(fake_response_text);
4481 /*************************************************
4482 * Create ACL variable *
4483 *************************************************/
4485 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4486 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4489 name pointer to the variable's name, starting with c or m
4491 Returns the pointer to variable's tree node
4495 acl_var_create(uschar *name)
4497 tree_node *node, **root;
4498 root = (name[0] == 'c')? &acl_var_c : &acl_var_m;
4499 node = tree_search(*root, name);
4502 node = store_get(sizeof(tree_node) + Ustrlen(name));
4503 Ustrcpy(node->name, name);
4504 (void)tree_insertnode(root, node);
4506 node->data.ptr = NULL;
4512 /*************************************************
4513 * Write an ACL variable in spool format *
4514 *************************************************/
4516 /* This function is used as a callback for tree_walk when writing variables to
4517 the spool file. To retain spool file compatibility, what is written is -aclc or
4518 -aclm followed by the rest of the name and the data length, space separated,
4519 then the value itself, starting on a new line, and terminated by an additional
4520 newline. When we had only numbered ACL variables, the first line might look
4521 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4525 name of the variable
4526 value of the variable
4527 ctx FILE pointer (as a void pointer)
4533 acl_var_write(uschar *name, uschar *value, void *ctx)
4535 FILE *f = (FILE *)ctx;
4536 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);