1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
9 /* Code for handling Access Control Lists (ACLs) */
14 /* Default callout timeout */
16 #define CALLOUT_TIMEOUT_DEFAULT 30
18 /* Default quota cache TTLs */
20 #define QUOTA_POS_DEFAULT (5*60)
21 #define QUOTA_NEG_DEFAULT (60*60)
24 /* ACL verb codes - keep in step with the table of verbs that follows */
26 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
31 static uschar *verbs[] = {
32 [ACL_ACCEPT] = US"accept",
33 [ACL_DEFER] = US"defer",
34 [ACL_DENY] = US"deny",
35 [ACL_DISCARD] = US"discard",
36 [ACL_DROP] = US"drop",
37 [ACL_REQUIRE] = US"require",
41 /* For each verb, the conditions for which "message" or "log_message" are used
42 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
43 "accept", the FAIL case is used only after "endpass", but that is selected in
46 static int msgcond[] = {
47 [ACL_ACCEPT] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
48 [ACL_DEFER] = BIT(OK),
50 [ACL_DISCARD] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
52 [ACL_REQUIRE] = BIT(FAIL) | BIT(FAIL_DROP),
56 /* ACL condition and modifier codes - keep in step with the table that
63 #ifdef EXPERIMENTAL_BRIGHTMAIL
69 #ifdef EXPERIMENTAL_DCC
72 #ifdef WITH_CONTENT_SCAN
90 ACLC_LOG_REJECT_TARGET,
92 #ifdef WITH_CONTENT_SCAN
96 #ifdef WITH_CONTENT_SCAN
102 #ifdef WITH_CONTENT_SCAN
109 #ifdef WITH_CONTENT_SCAN
119 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
120 "message", "log_message", "log_reject_target", "logwrite", "queue" and "set" are
121 modifiers that look like conditions but always return TRUE. They are used for
122 their side effects. Do not invent new modifier names that result in one name
123 being the prefix of another; the binary-search in the list will go wrong. */
125 typedef struct condition_def {
128 /* Flag to indicate the condition/modifier has a string expansion done
129 at the outer level. In the other cases, expansion already occurs in the
130 checking functions. */
131 BOOL expand_at_top:1;
135 /* Bit map vector of which conditions and modifiers are not allowed at certain
136 times. For each condition and modifier, there's a bitmap of dis-allowed times.
137 For some, it is easier to specify the negation of a small number of allowed
143 static condition_def conditions[] = {
144 [ACLC_ACL] = { US"acl", FALSE, FALSE, 0 },
146 [ACLC_ADD_HEADER] = { US"add_header", TRUE, TRUE,
148 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
149 ACL_BIT_PREDATA | ACL_BIT_DATA |
153 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
155 ACL_BIT_NOTSMTP_START),
158 [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE,
159 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
160 ACL_BIT_CONNECT | ACL_BIT_HELO,
162 #ifdef EXPERIMENTAL_BRIGHTMAIL
163 [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE,
165 ACL_BIT_CONNECT | ACL_BIT_HELO |
166 ACL_BIT_DATA | ACL_BIT_MIME |
167 # ifndef DISABLE_PRDR
170 ACL_BIT_ETRN | ACL_BIT_EXPN |
172 ACL_BIT_MAIL | ACL_BIT_STARTTLS |
173 ACL_BIT_VRFY | ACL_BIT_PREDATA |
174 ACL_BIT_NOTSMTP_START,
177 [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 },
178 [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 },
180 /* Certain types of control are always allowed, so we let it through
181 always and check in the control processing itself. */
182 [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 },
184 #ifdef EXPERIMENTAL_DCC
185 [ACLC_DCC] = { US"dcc", TRUE, FALSE,
188 # ifndef DISABLE_PRDR
194 #ifdef WITH_CONTENT_SCAN
195 [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
198 [ACLC_DELAY] = { US"delay", TRUE, TRUE, ACL_BIT_NOTQUIT },
200 [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
201 [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
204 [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DATA },
207 /* Explicit key lookups can be made in non-smtp ACLs so pass
208 always and check in the verify processing itself. */
209 [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 },
211 [ACLC_DOMAINS] = { US"domains", FALSE, FALSE,
213 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
219 [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE,
220 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
224 [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 },
226 [ACLC_HOSTS] = { US"hosts", FALSE, FALSE,
227 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
229 [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE,
231 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
238 [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 },
239 [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 },
240 [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 },
242 #ifdef WITH_CONTENT_SCAN
243 [ACLC_MALWARE] = { US"malware", TRUE, FALSE,
246 # ifndef DISABLE_PRDR
253 [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 },
254 #ifdef WITH_CONTENT_SCAN
255 [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
258 [ACLC_QUEUE] = { US"queue", TRUE, TRUE,
266 [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 },
267 [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~ACL_BIT_RCPT },
269 #ifdef WITH_CONTENT_SCAN
270 [ACLC_REGEX] = { US"regex", TRUE, FALSE,
273 # ifndef DISABLE_PRDR
281 [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE,
283 ~(ACL_BIT_MAIL|ACL_BIT_RCPT |
284 ACL_BIT_PREDATA | ACL_BIT_DATA |
288 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
289 ACL_BIT_NOTSMTP_START),
291 [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE,
292 ACL_BIT_AUTH | ACL_BIT_CONNECT |
294 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
295 ACL_BIT_ETRN | ACL_BIT_EXPN |
296 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
298 [ACLC_SENDERS] = { US"senders", FALSE, FALSE,
299 ACL_BIT_AUTH | ACL_BIT_CONNECT |
301 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
302 ACL_BIT_ETRN | ACL_BIT_EXPN |
303 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
306 [ACLC_SET] = { US"set", TRUE, TRUE, 0 },
308 #ifdef WITH_CONTENT_SCAN
309 [ACLC_SPAM] = { US"spam", TRUE, FALSE,
310 (unsigned int) ~(ACL_BIT_DATA |
311 # ifndef DISABLE_PRDR
318 [ACLC_SPF] = { US"spf", TRUE, FALSE,
319 ACL_BIT_AUTH | ACL_BIT_CONNECT |
320 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
321 ACL_BIT_ETRN | ACL_BIT_EXPN |
322 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
323 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
325 [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE,
326 ACL_BIT_AUTH | ACL_BIT_CONNECT |
327 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
328 ACL_BIT_ETRN | ACL_BIT_EXPN |
329 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
330 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
333 [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 },
335 /* Certain types of verify are always allowed, so we let it through
336 always and check in the verify function itself */
337 [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 },
342 /* Return values from decode_control(); used as index so keep in step
343 with the controls_list table that follows! */
346 CONTROL_AUTH_UNADVERTISED,
347 #ifdef EXPERIMENTAL_BRIGHTMAIL
350 CONTROL_CASEFUL_LOCAL_PART,
351 CONTROL_CASELOWER_LOCAL_PART,
352 CONTROL_CUTTHROUGH_DELIVERY,
358 CONTROL_DMARC_VERIFY,
359 CONTROL_DMARC_FORENSIC,
362 CONTROL_ENFORCE_SYNC,
363 CONTROL_ERROR, /* pseudo-value for decode errors */
368 CONTROL_NO_CALLOUT_FLUSH,
369 CONTROL_NO_DELAY_FLUSH,
370 CONTROL_NO_ENFORCE_SYNC,
371 #ifdef WITH_CONTENT_SCAN
372 CONTROL_NO_MBOX_UNSPOOL,
374 CONTROL_NO_MULTILINE,
375 CONTROL_NO_PIPELINING,
379 CONTROL_SUPPRESS_LOCAL_FIXUPS,
381 CONTROL_UTF8_DOWNCONVERT,
387 /* Structure listing various control arguments, with their characteristics.
388 For each control, there's a bitmap of dis-allowed times. For some, it is easier
389 to specify the negation of a small number of allowed times. */
391 typedef struct control_def {
393 BOOL has_option; /* Has /option(s) following */
394 unsigned forbids; /* bitmap of dis-allowed times */
397 static control_def controls_list[] = {
398 /* name has_option forbids */
399 [CONTROL_AUTH_UNADVERTISED] =
400 { US"allow_auth_unadvertised", FALSE,
402 ~(ACL_BIT_CONNECT | ACL_BIT_HELO)
404 #ifdef EXPERIMENTAL_BRIGHTMAIL
406 { US"bmi_run", FALSE, 0 },
408 [CONTROL_CASEFUL_LOCAL_PART] =
409 { US"caseful_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
410 [CONTROL_CASELOWER_LOCAL_PART] =
411 { US"caselower_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
412 [CONTROL_CUTTHROUGH_DELIVERY] =
413 { US"cutthrough_delivery", TRUE, 0 },
415 { US"debug", TRUE, 0 },
418 [CONTROL_DKIM_VERIFY] =
419 { US"dkim_disable_verify", FALSE,
420 ACL_BIT_DATA | ACL_BIT_NOTSMTP |
421 # ifndef DISABLE_PRDR
424 ACL_BIT_NOTSMTP_START
429 [CONTROL_DMARC_VERIFY] =
430 { US"dmarc_disable_verify", FALSE,
431 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
433 [CONTROL_DMARC_FORENSIC] =
434 { US"dmarc_enable_forensic", FALSE,
435 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
441 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | ACL_BIT_NOTQUIT
443 [CONTROL_ENFORCE_SYNC] =
444 { US"enforce_sync", FALSE,
445 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
448 /* Pseudo-value for decode errors */
450 { US"error", FALSE, 0 },
452 [CONTROL_FAKEDEFER] =
453 { US"fakedefer", TRUE,
455 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
456 ACL_BIT_PREDATA | ACL_BIT_DATA |
462 [CONTROL_FAKEREJECT] =
463 { US"fakereject", TRUE,
465 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
466 ACL_BIT_PREDATA | ACL_BIT_DATA |
475 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
476 ACL_BIT_PREDATA | ACL_BIT_DATA |
477 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
478 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
481 [CONTROL_NO_CALLOUT_FLUSH] =
482 { US"no_callout_flush", FALSE,
483 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
485 [CONTROL_NO_DELAY_FLUSH] =
486 { US"no_delay_flush", FALSE,
487 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
490 [CONTROL_NO_ENFORCE_SYNC] =
491 { US"no_enforce_sync", FALSE,
492 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
494 #ifdef WITH_CONTENT_SCAN
495 [CONTROL_NO_MBOX_UNSPOOL] =
496 { US"no_mbox_unspool", FALSE,
498 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
499 ACL_BIT_PREDATA | ACL_BIT_DATA |
500 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
504 [CONTROL_NO_MULTILINE] =
505 { US"no_multiline_responses", FALSE,
506 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
508 [CONTROL_NO_PIPELINING] =
509 { US"no_pipelining", FALSE,
510 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
516 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
517 ACL_BIT_PREDATA | ACL_BIT_DATA |
518 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
519 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
522 [CONTROL_SUBMISSION] =
523 { US"submission", TRUE,
525 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA)
527 [CONTROL_SUPPRESS_LOCAL_FIXUPS] =
528 { US"suppress_local_fixups", FALSE,
530 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
531 ACL_BIT_NOTSMTP_START)
534 [CONTROL_UTF8_DOWNCONVERT] =
535 { US"utf8_downconvert", TRUE, (unsigned) ~(ACL_BIT_RCPT | ACL_BIT_VRFY)
540 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
541 caches its result in a tree to avoid repeated DNS queries. The result is an
542 integer code which is used as an index into the following tables of
543 explanatory strings and verification return codes. */
545 static tree_node *csa_cache = NULL;
547 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
548 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
550 /* The acl_verify_csa() return code is translated into an acl_verify() return
551 code using the following table. It is OK unless the client is definitely not
552 authorized. This is because CSA is supposed to be optional for sending sites,
553 so recipients should not be too strict about checking it - especially because
554 DNS problems are quite likely to occur. It's possible to use $csa_status in
555 further ACL conditions to distinguish ok, unknown, and defer if required, but
556 the aim is to make the usual configuration simple. */
558 static int csa_return_code[] = {
561 [CSA_DEFER_SRV] = OK,
562 [CSA_DEFER_ADDR] = OK,
563 [CSA_FAIL_EXPLICIT] = FAIL,
564 [CSA_FAIL_DOMAIN] = FAIL,
565 [CSA_FAIL_NOADDR] = FAIL,
566 [CSA_FAIL_MISMATCH] = FAIL
569 static uschar *csa_status_string[] = {
570 [CSA_UNKNOWN] = US"unknown",
572 [CSA_DEFER_SRV] = US"defer",
573 [CSA_DEFER_ADDR] = US"defer",
574 [CSA_FAIL_EXPLICIT] = US"fail",
575 [CSA_FAIL_DOMAIN] = US"fail",
576 [CSA_FAIL_NOADDR] = US"fail",
577 [CSA_FAIL_MISMATCH] = US"fail"
580 static uschar *csa_reason_string[] = {
581 [CSA_UNKNOWN] = US"unknown",
583 [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)",
584 [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)",
585 [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)",
586 [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)",
587 [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)",
588 [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)"
591 /* Options for the ratelimit condition. Note that there are two variants of
592 the per_rcpt option, depending on the ACL that is used to measure the rate.
593 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
594 so the two variants must have the same internal representation as well as
595 the same configuration string. */
598 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
599 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
602 #define RATE_SET(var,new) \
603 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
605 static uschar *ratelimit_option_string[] = {
606 [RATE_PER_WHAT] = US"?",
607 [RATE_PER_CLASH] = US"!",
608 [RATE_PER_ADDR] = US"per_addr",
609 [RATE_PER_BYTE] = US"per_byte",
610 [RATE_PER_CMD] = US"per_cmd",
611 [RATE_PER_CONN] = US"per_conn",
612 [RATE_PER_MAIL] = US"per_mail",
613 [RATE_PER_RCPT] = US"per_rcpt",
614 [RATE_PER_ALLRCPTS] = US"per_rcpt"
617 /* Enable recursion between acl_check_internal() and acl_check_condition() */
619 static int acl_check_wargs(int, address_item *, const uschar *, uschar **,
623 /*************************************************
624 * Find control in list *
625 *************************************************/
627 /* The lists are always in order, so binary chop can be used.
630 name the control name to search for
631 ol the first entry in the control list
632 last one more than the offset of the last entry in the control list
634 Returns: index of a control entry, or -1 if not found
638 find_control(const uschar * name, control_def * ol, int last)
640 for (int first = 0; last > first; )
642 int middle = (first + last)/2;
643 uschar * s = ol[middle].name;
644 int c = Ustrncmp(name, s, Ustrlen(s));
645 if (c == 0) return middle;
646 else if (c > 0) first = middle + 1;
654 /*************************************************
655 * Pick out condition from list *
656 *************************************************/
658 /* Use a binary chop method
662 list list of conditions
665 Returns: offset in list, or -1 if not found
669 acl_checkcondition(uschar * name, condition_def * list, int end)
671 for (int start = 0; start < end; )
673 int mid = (start + end)/2;
674 int c = Ustrcmp(name, list[mid].name);
675 if (c == 0) return mid;
676 if (c < 0) end = mid;
677 else start = mid + 1;
683 /*************************************************
684 * Pick out name from list *
685 *************************************************/
687 /* Use a binary chop method
694 Returns: offset in list, or -1 if not found
698 acl_checkname(uschar *name, uschar **list, int end)
700 for (int start = 0; start < end; )
702 int mid = (start + end)/2;
703 int c = Ustrcmp(name, list[mid]);
704 if (c == 0) return mid;
705 if (c < 0) end = mid; else start = mid + 1;
712 /*************************************************
713 * Read and parse one ACL *
714 *************************************************/
716 /* This function is called both from readconf in order to parse the ACLs in the
717 configuration file, and also when an ACL is encountered dynamically (e.g. as
718 the result of an expansion). It is given a function to call in order to
719 retrieve the lines of the ACL. This function handles skipping comments and
720 blank lines (where relevant).
723 func function to get next line of ACL
724 error where to put an error message
726 Returns: pointer to ACL, or NULL
727 NULL can be legal (empty ACL); in this case error will be NULL
731 acl_read(uschar *(*func)(void), uschar **error)
733 acl_block *yield = NULL;
734 acl_block **lastp = &yield;
735 acl_block *this = NULL;
736 acl_condition_block *cond;
737 acl_condition_block **condp = NULL;
742 while ((s = (*func)()))
745 BOOL negated = FALSE;
746 uschar *saveline = s;
747 uschar name[EXIM_DRIVERNAME_MAX];
749 /* Conditions (but not verbs) are allowed to be negated by an initial
752 if (Uskip_whitespace(&s) == '!')
758 /* Read the name of a verb or a condition, or the start of a new ACL, which
759 can be started by a name, or by a macro definition. */
761 s = readconf_readname(name, sizeof(name), s);
762 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
764 /* If a verb is unrecognized, it may be another condition or modifier that
765 continues the previous verb. */
767 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
771 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
783 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
786 this = store_get(sizeof(acl_block), FALSE);
788 lastp = &(this->next);
790 this->condition = NULL;
792 this->srcline = config_lineno; /* for debug output */
793 this->srcfile = config_filename; /**/
794 condp = &(this->condition);
795 if (*s == 0) continue; /* No condition on this line */
801 s = readconf_readname(name, sizeof(name), s); /* Condition name */
804 /* Handle a condition or modifier. */
806 if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0)
808 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
813 /* The modifiers may not be negated */
815 if (negated && conditions[c].is_modifier)
817 *error = string_sprintf("ACL error: negation is not allowed with "
818 "\"%s\"", conditions[c].name);
822 /* ENDPASS may occur only with ACCEPT or DISCARD. */
824 if (c == ACLC_ENDPASS &&
825 this->verb != ACL_ACCEPT &&
826 this->verb != ACL_DISCARD)
828 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
829 conditions[c].name, verbs[this->verb]);
833 cond = store_get(sizeof(acl_condition_block), FALSE);
836 cond->u.negated = negated;
839 condp = &(cond->next);
841 /* The "set" modifier is different in that its argument is "name=value"
842 rather than just a value, and we can check the validity of the name, which
843 gives us a variable name to insert into the data block. The original ACL
844 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
845 extended to 20 of each type, but after that people successfully argued for
846 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
847 After that, we allow alphanumerics and underscores, but the first character
848 after c or m must be a digit or an underscore. This retains backwards
853 if ( Ustrncmp(s, "dkim_verify_status", 18) == 0
854 || Ustrncmp(s, "dkim_verify_reason", 18) == 0)
856 uschar * endptr = s+18;
858 if (isalnum(*endptr))
860 *error = string_sprintf("invalid variable name after \"set\" in ACL "
861 "modifier \"set %s\" "
862 "(only \"dkim_verify_status\" or \"dkim_verify_reason\" permitted)",
866 cond->u.varname = string_copyn(s, 18);
868 Uskip_whitespace(&s);
875 if (Ustrncmp(s, "acl_c", 5) != 0 && Ustrncmp(s, "acl_m", 5) != 0)
877 *error = string_sprintf("invalid variable name after \"set\" in ACL "
878 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
883 if (!isdigit(*endptr) && *endptr != '_')
885 *error = string_sprintf("invalid variable name after \"set\" in ACL "
886 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
891 while (*endptr && *endptr != '=' && !isspace(*endptr))
893 if (!isalnum(*endptr) && *endptr != '_')
895 *error = string_sprintf("invalid character \"%c\" in variable name "
896 "in ACL modifier \"set %s\"", *endptr, s);
902 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
904 Uskip_whitespace(&s);
907 /* For "set", we are now positioned for the data. For the others, only
908 "endpass" has no data */
910 if (c != ACLC_ENDPASS)
914 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
915 conditions[c].is_modifier ? US"modifier" : US"condition");
918 Uskip_whitespace(&s);
919 cond->arg = string_copy(s);
928 /*************************************************
929 * Set up added header line(s) *
930 *************************************************/
932 /* This function is called by the add_header modifier, and also from acl_warn()
933 to implement the now-deprecated way of adding header lines using "message" on a
934 "warn" verb. The argument is treated as a sequence of header lines which are
935 added to a chain, provided there isn't an identical one already there.
937 Argument: string of header lines
942 setup_header(const uschar *hstring)
945 int hlen = Ustrlen(hstring);
947 /* Ignore any leading newlines */
948 while (*hstring == '\n') hstring++, hlen--;
950 /* An empty string does nothing; ensure exactly one final newline. */
951 if (hlen <= 0) return;
952 if (hstring[--hlen] != '\n') /* no newline */
953 q = string_sprintf("%s\n", hstring);
954 else if (hstring[hlen-1] == '\n') /* double newline */
956 uschar * s = string_copy(hstring);
957 while(s[--hlen] == '\n')
964 /* Loop for multiple header lines, taking care about continuations */
966 for (p = q; *p; p = q)
970 int newtype = htype_add_bot;
971 header_line **hptr = &acl_added_headers;
973 /* Find next header line within the string */
977 q = Ustrchr(q, '\n'); /* we know there was a newline */
978 if (*++q != ' ' && *q != '\t') break;
981 /* If the line starts with a colon, interpret the instruction for where to
982 add it. This temporarily sets up a new type. */
986 if (strncmpic(p, US":after_received:", 16) == 0)
988 newtype = htype_add_rec;
991 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
993 newtype = htype_add_rfc;
996 else if (strncmpic(p, US":at_start:", 10) == 0)
998 newtype = htype_add_top;
1001 else if (strncmpic(p, US":at_end:", 8) == 0)
1003 newtype = htype_add_bot;
1006 while (*p == ' ' || *p == '\t') p++;
1009 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1010 to the front of it. */
1012 for (s = p; s < q - 1; s++)
1013 if (*s == ':' || !isgraph(*s)) break;
1015 hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p);
1016 hlen = Ustrlen(hdr);
1018 /* See if this line has already been added */
1022 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1023 hptr = &(*hptr)->next;
1026 /* Add if not previously present */
1030 /* The header_line struct itself is not tainted, though it points to
1031 possibly tainted data. */
1032 header_line * h = store_get(sizeof(header_line), FALSE);
1045 /*************************************************
1046 * List the added header lines *
1047 *************************************************/
1053 for (header_line * h = acl_added_headers; h; h = h->next)
1056 if (h->text[i-1] == '\n') i--;
1057 g = string_append_listele_n(g, '\n', h->text, i);
1060 return g ? g->s : NULL;
1064 /*************************************************
1065 * Set up removed header line(s) *
1066 *************************************************/
1068 /* This function is called by the remove_header modifier. The argument is
1069 treated as a sequence of header names which are added to a colon separated
1070 list, provided there isn't an identical one already there.
1072 Argument: string of header names
1077 setup_remove_header(const uschar *hnames)
1080 acl_removed_headers = acl_removed_headers
1081 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1082 : string_copy(hnames);
1087 /*************************************************
1089 *************************************************/
1091 /* This function is called when a WARN verb's conditions are true. It adds to
1092 the message's headers, and/or writes information to the log. In each case, this
1093 only happens once (per message for headers, per connection for log).
1095 ** NOTE: The header adding action using the "message" setting is historic, and
1096 its use is now deprecated. The new add_header modifier should be used instead.
1099 where ACL_WHERE_xxxx indicating which ACL this is
1100 user_message message for adding to headers
1101 log_message message for logging, if different
1107 acl_warn(int where, uschar *user_message, uschar *log_message)
1109 if (log_message != NULL && log_message != user_message)
1112 string_item *logged;
1114 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1115 string_printing(log_message));
1117 /* If a sender verification has failed, and the log message is "sender verify
1118 failed", add the failure message. */
1120 if (sender_verified_failed != NULL &&
1121 sender_verified_failed->message != NULL &&
1122 strcmpic(log_message, US"sender verify failed") == 0)
1123 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1125 /* Search previously logged warnings. They are kept in malloc
1126 store so they can be freed at the start of a new message. */
1128 for (logged = acl_warn_logged; logged; logged = logged->next)
1129 if (Ustrcmp(logged->text, text) == 0) break;
1133 int length = Ustrlen(text) + 1;
1134 log_write(0, LOG_MAIN, "%s", text);
1135 logged = store_malloc(sizeof(string_item) + length);
1136 logged->text = US logged + sizeof(string_item);
1137 memcpy(logged->text, text, length);
1138 logged->next = acl_warn_logged;
1139 acl_warn_logged = logged;
1143 /* If there's no user message, we are done. */
1145 if (!user_message) return;
1147 /* If this isn't a message ACL, we can't do anything with a user message.
1150 if (where > ACL_WHERE_NOTSMTP)
1152 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1153 "found in a non-message (%s) ACL: cannot specify header lines here: "
1154 "message ignored", acl_wherenames[where]);
1158 /* The code for setting up header lines is now abstracted into a separate
1159 function so that it can be used for the add_header modifier as well. */
1161 setup_header(user_message);
1166 /*************************************************
1167 * Verify and check reverse DNS *
1168 *************************************************/
1170 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1171 address if this has not yet been done. The host_name_lookup() function checks
1172 that one of these names resolves to an address list that contains the client IP
1173 address, so we don't actually have to do the check here.
1176 user_msgptr pointer for user message
1177 log_msgptr pointer for log message
1179 Returns: OK verification condition succeeded
1180 FAIL verification failed
1181 DEFER there was a problem verifying
1185 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1189 /* Previous success */
1191 if (sender_host_name != NULL) return OK;
1193 /* Previous failure */
1195 if (host_lookup_failed)
1197 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1201 /* Need to do a lookup */
1204 debug_printf_indent("looking up host name to force name/address consistency check\n");
1206 if ((rc = host_name_lookup()) != OK)
1208 *log_msgptr = rc == DEFER
1209 ? US"host lookup deferred for reverse lookup check"
1210 : string_sprintf("host lookup failed for reverse lookup check%s",
1212 return rc; /* DEFER or FAIL */
1215 host_build_sender_fullhost();
1221 /*************************************************
1222 * Check client IP address matches CSA target *
1223 *************************************************/
1225 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1226 response for address records belonging to the CSA target hostname. The section
1227 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1228 If one of the addresses matches the client's IP address, then the client is
1229 authorized by CSA. If there are target IP addresses but none of them match
1230 then the client is using an unauthorized IP address. If there are no target IP
1231 addresses then the client cannot be using an authorized IP address. (This is
1232 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1235 dnsa the DNS answer block
1236 dnss a DNS scan block for us to use
1237 reset option specifying what portion to scan, as described above
1238 target the target hostname to use for matching RR names
1240 Returns: CSA_OK successfully authorized
1241 CSA_FAIL_MISMATCH addresses found but none matched
1242 CSA_FAIL_NOADDR no target addresses found
1246 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1249 int rc = CSA_FAIL_NOADDR;
1251 for (dns_record * rr = dns_next_rr(dnsa, dnss, reset);
1253 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1255 /* Check this is an address RR for the target hostname. */
1259 && rr->type != T_AAAA
1263 if (strcmpic(target, rr->name) != 0) continue;
1265 rc = CSA_FAIL_MISMATCH;
1267 /* Turn the target address RR into a list of textual IP addresses and scan
1268 the list. There may be more than one if it is an A6 RR. */
1270 for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next)
1272 /* If the client IP address matches the target IP address, it's good! */
1274 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1276 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1280 /* If we found some target addresses but none of them matched, the client is
1281 using an unauthorized IP address, otherwise the target has no authorized IP
1289 /*************************************************
1290 * Verify Client SMTP Authorization *
1291 *************************************************/
1293 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1294 to find the CSA SRV record corresponding to the domain argument, or
1295 $sender_helo_name if no argument is provided. It then checks that the
1296 client is authorized, and that its IP address corresponds to the SRV
1297 target's address by calling acl_verify_csa_address() above. The address
1298 should have been returned in the DNS response's ADDITIONAL section, but if
1299 not we perform another DNS lookup to get it.
1302 domain pointer to optional parameter following verify = csa
1304 Returns: CSA_UNKNOWN no valid CSA record found
1305 CSA_OK successfully authorized
1306 CSA_FAIL_* client is definitely not authorized
1307 CSA_DEFER_* there was a DNS problem
1311 acl_verify_csa(const uschar *domain)
1314 const uschar *found;
1315 int priority, weight, port;
1319 int rc, type, yield;
1320 #define TARGET_SIZE 256
1321 uschar * target = store_get(TARGET_SIZE, TRUE);
1323 /* Work out the domain we are using for the CSA lookup. The default is the
1324 client's HELO domain. If the client has not said HELO, use its IP address
1325 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1327 while (isspace(*domain) && *domain != '\0') ++domain;
1328 if (*domain == '\0') domain = sender_helo_name;
1329 if (!domain) domain = sender_host_address;
1330 if (!sender_host_address) return CSA_UNKNOWN;
1332 /* If we have an address literal, strip off the framing ready for turning it
1333 into a domain. The framing consists of matched square brackets possibly
1334 containing a keyword and a colon before the actual IP address. */
1336 if (domain[0] == '[')
1338 const uschar *start = Ustrchr(domain, ':');
1339 if (start == NULL) start = domain;
1340 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1343 /* Turn domains that look like bare IP addresses into domains in the reverse
1344 DNS. This code also deals with address literals and $sender_host_address. It's
1345 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1346 address literals, but it's probably the most friendly thing to do. This is an
1347 extension to CSA, so we allow it to be turned off for proper conformance. */
1349 if (string_is_ip_address(domain, NULL) != 0)
1351 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1352 domain = dns_build_reverse(domain);
1355 /* Find out if we've already done the CSA check for this domain. If we have,
1356 return the same result again. Otherwise build a new cached result structure
1357 for this domain. The name is filled in now, and the value is filled in when
1358 we return from this function. */
1360 if ((t = tree_search(csa_cache, domain)))
1363 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain), is_tainted(domain));
1364 Ustrcpy(t->name, domain);
1365 (void)tree_insertnode(&csa_cache, t);
1367 /* Now we are ready to do the actual DNS lookup(s). */
1370 dnsa = store_get_dns_answer();
1371 switch (dns_special_lookup(dnsa, domain, T_CSA, &found))
1373 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1376 yield = CSA_DEFER_SRV;
1379 /* If we found nothing, the client's authorization is unknown. */
1383 yield = CSA_UNKNOWN;
1386 /* We got something! Go on to look at the reply in more detail. */
1392 /* Scan the reply for well-formed CSA SRV records. */
1394 for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1396 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1398 const uschar * p = rr->data;
1400 /* Extract the numerical SRV fields (p is incremented) */
1402 GETSHORT(priority, p);
1403 GETSHORT(weight, p);
1407 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1409 /* Check the CSA version number */
1411 if (priority != 1) continue;
1413 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1414 found by dns_special_lookup() is a parent of the one we asked for), we check
1415 the subdomain assertions in the port field. At the moment there's only one
1416 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1417 SRV records of their own. */
1419 if (Ustrcmp(found, domain) != 0)
1421 yield = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1425 /* This CSA SRV record refers directly to our domain, so we check the value
1426 in the weight field to work out the domain's authorization. 0 and 1 are
1427 unauthorized; 3 means the client is authorized but we can't check the IP
1428 address in order to authenticate it, so we treat it as unknown; values
1429 greater than 3 are undefined. */
1433 yield = CSA_FAIL_DOMAIN;
1437 if (weight > 2) continue;
1439 /* Weight == 2, which means the domain is authorized. We must check that the
1440 client's IP address is listed as one of the SRV target addresses. Save the
1441 target hostname then break to scan the additional data for its addresses. */
1443 (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, p,
1444 (DN_EXPAND_ARG4_TYPE)target, TARGET_SIZE);
1446 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1451 /* If we didn't break the loop then no appropriate records were found. */
1455 yield = CSA_UNKNOWN;
1459 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1460 A target of "." indicates there are no valid addresses, so the client cannot
1461 be authorized. (This is an odd configuration because weight=2 target=. is
1462 equivalent to weight=1, but we check for it in order to keep load off the
1463 root name servers.) Note that dn_expand() turns "." into "". */
1465 if (Ustrcmp(target, "") == 0)
1467 yield = CSA_FAIL_NOADDR;
1471 /* Scan the additional section of the CSA SRV reply for addresses belonging
1472 to the target. If the name server didn't return any additional data (e.g.
1473 because it does not fully support SRV records), we need to do another lookup
1474 to obtain the target addresses; otherwise we have a definitive result. */
1476 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ADDITIONAL, target);
1477 if (rc != CSA_FAIL_NOADDR)
1483 /* The DNS lookup type corresponds to the IP version used by the client. */
1486 if (Ustrchr(sender_host_address, ':') != NULL)
1489 #endif /* HAVE_IPV6 */
1493 lookup_dnssec_authenticated = NULL;
1494 switch (dns_lookup(dnsa, target, type, NULL))
1496 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1499 yield = CSA_DEFER_ADDR;
1502 /* If the query succeeded, scan the addresses and return the result. */
1505 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ANSWERS, target);
1506 if (rc != CSA_FAIL_NOADDR)
1511 /* else fall through */
1513 /* If the target has no IP addresses, the client cannot have an authorized
1514 IP address. However, if the target site uses A6 records (not AAAA records)
1515 we have to do yet another lookup in order to check them. */
1519 yield = CSA_FAIL_NOADDR;
1525 store_free_dns_answer(dnsa);
1526 return t->data.val = yield;
1531 /*************************************************
1532 * Handle verification (address & other) *
1533 *************************************************/
1535 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1536 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1537 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1542 unsigned where_allowed; /* bitmap */
1543 BOOL no_options; /* Never has /option(s) following */
1544 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1546 static verify_type_t verify_type_list[] = {
1547 /* name value where no-opt opt-sep */
1548 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, (unsigned)~0, FALSE, 0 },
1549 { US"certificate", VERIFY_CERT, (unsigned)~0, TRUE, 0 },
1550 { US"helo", VERIFY_HELO, (unsigned)~0, TRUE, 0 },
1551 { US"csa", VERIFY_CSA, (unsigned)~0, FALSE, 0 },
1552 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BITS_HAVEDATA, TRUE, 0 },
1553 { US"not_blind", VERIFY_NOT_BLIND, ACL_BITS_HAVEDATA, FALSE, 0 },
1554 { US"header_sender", VERIFY_HDR_SNDR, ACL_BITS_HAVEDATA, FALSE, 0 },
1555 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1556 | ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1558 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1559 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BITS_HAVEDATA, TRUE, 0 },
1560 #ifdef EXPERIMENTAL_ARC
1561 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1566 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1567 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1568 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1569 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1575 BOOL has_option; /* Has =option(s) following */
1576 BOOL timeval; /* Has a time value */
1578 static callout_opt_t callout_opt_list[] = {
1579 /* name value flag has-opt has-time */
1580 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1581 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1582 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1583 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1584 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1585 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1586 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1587 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1588 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1589 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1590 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1591 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1592 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1598 v_period(const uschar * s, const uschar * arg, uschar ** log_msgptr)
1601 if ((period = readconf_readtime(s, 0, FALSE)) < 0)
1603 *log_msgptr = string_sprintf("bad time value in ACL condition "
1604 "\"verify %s\"", arg);
1611 /* This function implements the "verify" condition. It is called when
1612 encountered in any ACL, because some tests are almost always permitted. Some
1613 just don't make sense, and always fail (for example, an attempt to test a host
1614 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1617 where where called from
1618 addr the recipient address that the ACL is handling, or NULL
1619 arg the argument of "verify"
1620 user_msgptr pointer for user message
1621 log_msgptr pointer for log message
1622 basic_errno where to put verify errno
1624 Returns: OK verification condition succeeded
1625 FAIL verification failed
1626 DEFER there was a problem verifying
1631 acl_verify(int where, address_item *addr, const uschar *arg,
1632 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1636 int callout_overall = -1;
1637 int callout_connect = -1;
1638 int verify_options = 0;
1640 BOOL verify_header_sender = FALSE;
1641 BOOL defer_ok = FALSE;
1642 BOOL callout_defer_ok = FALSE;
1643 BOOL no_details = FALSE;
1644 BOOL success_on_redirect = FALSE;
1646 int quota_pos_cache = QUOTA_POS_DEFAULT, quota_neg_cache = QUOTA_NEG_DEFAULT;
1647 address_item *sender_vaddr = NULL;
1648 uschar *verify_sender_address = NULL;
1649 uschar *pm_mailfrom = NULL;
1650 uschar *se_mailfrom = NULL;
1652 /* Some of the verify items have slash-separated options; some do not. Diagnose
1653 an error if options are given for items that don't expect them.
1656 uschar *slash = Ustrchr(arg, '/');
1657 const uschar *list = arg;
1658 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
1661 if (!ss) goto BAD_VERIFY;
1663 /* Handle name/address consistency verification in a separate function. */
1665 for (vp = verify_type_list;
1666 CS vp < CS verify_type_list + sizeof(verify_type_list);
1669 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1670 : strcmpic (ss, vp->name) == 0)
1672 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1675 if (vp->no_options && slash)
1677 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1678 "(this verify item has no options)", arg);
1681 if (!(vp->where_allowed & BIT(where)))
1683 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1684 vp->name, acl_wherenames[where]);
1689 case VERIFY_REV_HOST_LKUP:
1690 if (!sender_host_address) return OK;
1691 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1692 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1693 if (strcmpic(ss, US"defer_ok") == 0)
1698 /* TLS certificate verification is done at STARTTLS time; here we just
1699 test whether it was successful or not. (This is for optional verification; for
1700 mandatory verification, the connection doesn't last this long.) */
1702 if (tls_in.certificate_verified) return OK;
1703 *user_msgptr = US"no verified certificate";
1707 /* We can test the result of optional HELO verification that might have
1708 occurred earlier. If not, we can attempt the verification now. */
1710 if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo();
1711 return f.helo_verified ? OK : FAIL;
1714 /* Do Client SMTP Authorization checks in a separate function, and turn the
1715 result code into user-friendly strings. */
1717 rc = acl_verify_csa(list);
1718 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1719 csa_reason_string[rc]);
1720 csa_status = csa_status_string[rc];
1721 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1722 return csa_return_code[rc];
1724 #ifdef EXPERIMENTAL_ARC
1726 { /* Do Authenticated Received Chain checks in a separate function. */
1727 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1731 if (!(arc_state = acl_verify_arc())) return DEFER;
1732 DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state,
1733 arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":"");
1735 if (!condlist) condlist = US"none:pass";
1736 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1737 if (Ustrcmp(arc_state, cond) == 0) return OK;
1742 case VERIFY_HDR_SYNTAX:
1743 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1744 a syntax error, we return details of the error to the sender if configured to
1745 send out full details. (But a "message" setting on the ACL can override, as
1748 rc = verify_check_headers(log_msgptr);
1749 if (rc != OK && *log_msgptr)
1750 if (smtp_return_error_details)
1751 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1753 acl_verify_message = *log_msgptr;
1756 case VERIFY_HDR_NAMES_ASCII:
1757 /* Check that all header names are true 7 bit strings
1758 See RFC 5322, 2.2. and RFC 6532, 3. */
1760 rc = verify_check_header_names_ascii(log_msgptr);
1761 if (rc != OK && smtp_return_error_details && *log_msgptr)
1762 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1765 case VERIFY_NOT_BLIND:
1766 /* Check that no recipient of this message is "blind", that is, every envelope
1767 recipient must be mentioned in either To: or Cc:. */
1769 BOOL case_sensitive = TRUE;
1771 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1772 if (strcmpic(ss, US"case_insensitive") == 0)
1773 case_sensitive = FALSE;
1776 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1777 "condition \"verify %s\"", ss, arg);
1781 if ((rc = verify_check_notblind(case_sensitive)) != OK)
1783 *log_msgptr = US"bcc recipient detected";
1784 if (smtp_return_error_details)
1785 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1790 /* The remaining verification tests check recipient and sender addresses,
1791 either from the envelope or from the header. There are a number of
1792 slash-separated options that are common to all of them. */
1794 case VERIFY_HDR_SNDR:
1795 verify_header_sender = TRUE;
1799 /* In the case of a sender, this can optionally be followed by an address to use
1800 in place of the actual sender (rare special-case requirement). */
1804 verify_sender_address = sender_address;
1807 while (isspace(*s)) s++;
1808 if (*s++ != '=') goto BAD_VERIFY;
1809 while (isspace(*s)) s++;
1810 verify_sender_address = string_copy(s);
1821 /* Remaining items are optional; they apply to sender and recipient
1822 verification, including "header sender" verification. */
1824 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1826 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1827 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1828 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1830 /* These two old options are left for backwards compatibility */
1832 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1834 callout_defer_ok = TRUE;
1835 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1838 else if (strcmpic(ss, US"check_postmaster") == 0)
1841 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1844 /* The callout option has a number of sub-options, comma separated */
1846 else if (strncmpic(ss, US"callout", 7) == 0)
1848 callout = CALLOUT_TIMEOUT_DEFAULT;
1851 while (isspace(*ss)) ss++;
1854 const uschar * sublist = ss;
1857 while (isspace(*sublist)) sublist++;
1858 for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); )
1861 double period = 1.0F;
1863 for (op= callout_opt_list; op->name; op++)
1864 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1867 verify_options |= op->flag;
1870 opt += Ustrlen(op->name);
1871 while (isspace(*opt)) opt++;
1874 *log_msgptr = string_sprintf("'=' expected after "
1875 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1878 while (isspace(*opt)) opt++;
1880 if (op->timeval && (period = v_period(opt, arg, log_msgptr)) < 0)
1885 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1886 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1887 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1888 case CALLOUT_MAILFROM:
1889 if (!verify_header_sender)
1891 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1892 "callout option only for verify=header_sender (detected in ACL "
1893 "condition \"%s\")", arg);
1896 se_mailfrom = string_copy(opt);
1898 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1899 case CALLOUT_MAXWAIT: callout_overall = period; break;
1900 case CALLOUT_CONNECT: callout_connect = period; break;
1901 case CALLOUT_TIME: callout = period; break;
1907 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1908 "ACL condition \"%s\"", arg);
1914 /* The quota option has sub-options, comma-separated */
1916 else if (strncmpic(ss, US"quota", 5) == 0)
1921 while (isspace(*ss)) ss++;
1924 const uschar * sublist = ss;
1928 while (isspace(*sublist)) sublist++;
1929 for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); )
1930 if (Ustrncmp(opt, "cachepos=", 9) == 0)
1931 if ((period = v_period(opt += 9, arg, log_msgptr)) < 0)
1934 quota_pos_cache = period;
1935 else if (Ustrncmp(opt, "cacheneg=", 9) == 0)
1936 if ((period = v_period(opt += 9, arg, log_msgptr)) < 0)
1939 quota_neg_cache = period;
1940 else if (Ustrcmp(opt, "no_cache") == 0)
1941 quota_pos_cache = quota_neg_cache = 0;
1946 /* Option not recognized */
1950 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1951 "condition \"verify %s\"", ss, arg);
1956 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1957 (vopt_callout_recipsender|vopt_callout_recippmaster))
1959 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1960 "for a recipient callout";
1964 /* Handle quota verification */
1967 if (vp->value != VERIFY_RCPT)
1969 *log_msgptr = US"can only verify quota of recipient";
1973 if ((rc = verify_quota_call(addr->address,
1974 quota_pos_cache, quota_neg_cache, log_msgptr)) != OK)
1976 *basic_errno = errno;
1977 if (smtp_return_error_details)
1979 if (!*user_msgptr && *log_msgptr)
1980 *user_msgptr = string_sprintf("Rejected after %s: %s",
1981 smtp_names[smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)]],
1983 if (rc == DEFER) f.acl_temp_details = TRUE;
1990 /* Handle sender-in-header verification. Default the user message to the log
1991 message if giving out verification details. */
1993 if (verify_header_sender)
1997 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1998 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
2001 *basic_errno = verrno;
2002 if (smtp_return_error_details)
2004 if (!*user_msgptr && *log_msgptr)
2005 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
2006 if (rc == DEFER) f.acl_temp_details = TRUE;
2011 /* Handle a sender address. The default is to verify *the* sender address, but
2012 optionally a different address can be given, for special requirements. If the
2013 address is empty, we are dealing with a bounce message that has no sender, so
2014 we cannot do any checking. If the real sender address gets rewritten during
2015 verification (e.g. DNS widening), set the flag to stop it being rewritten again
2016 during message reception.
2018 A list of verified "sender" addresses is kept to try to avoid doing to much
2019 work repetitively when there are multiple recipients in a message and they all
2020 require sender verification. However, when callouts are involved, it gets too
2021 complicated because different recipients may require different callout options.
2022 Therefore, we always do a full sender verify when any kind of callout is
2023 specified. Caching elsewhere, for instance in the DNS resolver and in the
2024 callout handling, should ensure that this is not terribly inefficient. */
2026 else if (verify_sender_address)
2028 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
2030 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
2031 "sender verify callout";
2035 sender_vaddr = verify_checked_sender(verify_sender_address);
2036 if ( sender_vaddr /* Previously checked */
2037 && callout <= 0) /* No callout needed this time */
2039 /* If the "routed" flag is set, it means that routing worked before, so
2040 this check can give OK (the saved return code value, if set, belongs to a
2041 callout that was done previously). If the "routed" flag is not set, routing
2042 must have failed, so we use the saved return code. */
2044 if (testflag(sender_vaddr, af_verify_routed))
2048 rc = sender_vaddr->special_action;
2049 *basic_errno = sender_vaddr->basic_errno;
2051 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
2054 /* Do a new verification, and cache the result. The cache is used to avoid
2055 verifying the sender multiple times for multiple RCPTs when callouts are not
2056 specified (see comments above).
2058 The cache is also used on failure to give details in response to the first
2059 RCPT that gets bounced for this reason. However, this can be suppressed by
2060 the no_details option, which sets the flag that says "this detail has already
2061 been sent". The cache normally contains just one address, but there may be
2062 more in esoteric circumstances. */
2067 uschar *save_address_data = deliver_address_data;
2069 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
2071 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
2073 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
2074 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
2077 if (no_details) setflag(sender_vaddr, af_sverify_told);
2078 if (verify_sender_address[0] != 0)
2080 /* If this is the real sender address, save the unrewritten version
2081 for use later in receive. Otherwise, set a flag so that rewriting the
2082 sender in verify_address() does not update sender_address. */
2084 if (verify_sender_address == sender_address)
2085 sender_address_unrewritten = sender_address;
2087 verify_options |= vopt_fake_sender;
2089 if (success_on_redirect)
2090 verify_options |= vopt_success_on_redirect;
2092 /* The recipient, qualify, and expn options are never set in
2095 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2096 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2098 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2101 *basic_errno = sender_vaddr->basic_errno;
2104 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2105 debug_printf_indent("sender %s verified ok as %s\n",
2106 verify_sender_address, sender_vaddr->address);
2108 debug_printf_indent("sender %s verified ok\n",
2109 verify_sender_address);
2112 rc = OK; /* Null sender */
2114 /* Cache the result code */
2116 if (routed) setflag(sender_vaddr, af_verify_routed);
2117 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2118 sender_vaddr->special_action = rc;
2119 sender_vaddr->next = sender_verified_list;
2120 sender_verified_list = sender_vaddr;
2122 /* Restore the recipient address data, which might have been clobbered by
2123 the sender verification. */
2125 deliver_address_data = save_address_data;
2128 /* Put the sender address_data value into $sender_address_data */
2130 sender_address_data = sender_vaddr->prop.address_data;
2133 /* A recipient address just gets a straightforward verify; again we must handle
2134 the DEFER overrides. */
2140 if (success_on_redirect)
2141 verify_options |= vopt_success_on_redirect;
2143 /* We must use a copy of the address for verification, because it might
2147 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2148 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2149 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2151 *basic_errno = addr2.basic_errno;
2152 *log_msgptr = addr2.message;
2153 *user_msgptr = addr2.user_message ? addr2.user_message : addr2.message;
2155 /* Allow details for temporary error if the address is so flagged. */
2156 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2158 /* Make $address_data visible */
2159 deliver_address_data = addr2.prop.address_data;
2162 /* We have a result from the relevant test. Handle defer overrides first. */
2166 || callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER
2169 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2170 defer_ok? "defer_ok" : "callout_defer_ok");
2174 /* If we've failed a sender, set up a recipient message, and point
2175 sender_verified_failed to the address item that actually failed. */
2177 if (rc != OK && verify_sender_address)
2180 *log_msgptr = *user_msgptr = US"Sender verify failed";
2181 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2182 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2185 *log_msgptr = US"Could not complete sender verify callout";
2186 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2190 sender_verified_failed = sender_vaddr;
2193 /* Verifying an address messes up the values of $domain and $local_part,
2194 so reset them before returning if this is a RCPT ACL. */
2198 deliver_domain = addr->domain;
2199 deliver_localpart = addr->local_part;
2203 /* Syntax errors in the verify argument come here. */
2206 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2207 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2208 "or \"reverse_host_lookup\" at start of ACL condition "
2209 "\"verify %s\"", arg);
2216 /*************************************************
2217 * Check argument for control= modifier *
2218 *************************************************/
2220 /* Called from acl_check_condition() below.
2221 To handle the case "queue_only" we accept an _ in the
2222 initial / option-switch position.
2225 arg the argument string for control=
2226 pptr set to point to the terminating character
2227 where which ACL we are in
2228 log_msgptr for error messages
2230 Returns: CONTROL_xxx value
2234 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2240 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2241 || ( (c = arg[len = Ustrlen((d = controls_list+idx)->name)]) != 0
2242 && (!d->has_option || c != '/' && c != '_')
2245 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2246 return CONTROL_ERROR;
2256 /*************************************************
2257 * Return a ratelimit error *
2258 *************************************************/
2260 /* Called from acl_ratelimit() below
2263 log_msgptr for error messages
2264 format format string
2265 ... supplementary arguments
2271 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2275 string_cat(NULL, US"error in arguments to \"ratelimit\" condition: ");
2277 va_start(ap, format);
2278 g = string_vformat(g, SVFMT_EXTEND|SVFMT_REBUFFER, format, ap);
2281 gstring_release_unused(g);
2282 *log_msgptr = string_from_gstring(g);
2289 /*************************************************
2290 * Handle rate limiting *
2291 *************************************************/
2293 /* Called by acl_check_condition() below to calculate the result
2294 of the ACL ratelimit condition.
2296 Note that the return value might be slightly unexpected: if the
2297 sender's rate is above the limit then the result is OK. This is
2298 similar to the dnslists condition, and is so that you can write
2299 ACL clauses like: defer ratelimit = 15 / 1h
2302 arg the option string for ratelimit=
2303 where ACL_WHERE_xxxx indicating which ACL this is
2304 log_msgptr for error messages
2306 Returns: OK - Sender's rate is above limit
2307 FAIL - Sender's rate is below limit
2308 DEFER - Problem opening ratelimit database
2309 ERROR - Syntax error in options.
2313 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2315 double limit, period, count;
2318 uschar *unique = NULL;
2320 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2321 BOOL noupdate = FALSE, badacl = FALSE;
2322 int mode = RATE_PER_WHAT;
2324 tree_node **anchor, *t;
2325 open_db dbblock, *dbm;
2327 dbdata_ratelimit *dbd;
2328 dbdata_ratelimit_unique *dbdb;
2331 /* Parse the first two options and record their values in expansion
2332 variables. These variables allow the configuration to have informative
2333 error messages based on rate limits obtained from a table lookup. */
2335 /* First is the maximum number of messages per period / maximum burst
2336 size, which must be greater than or equal to zero. Zero is useful for
2337 rate measurement as opposed to rate limiting. */
2339 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2340 return ratelimit_error(log_msgptr, "sender rate limit not set");
2342 limit = Ustrtod(sender_rate_limit, &ss);
2343 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2344 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2345 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2347 if (limit < 0.0 || *ss != '\0')
2348 return ratelimit_error(log_msgptr,
2349 "\"%s\" is not a positive number", sender_rate_limit);
2351 /* Second is the rate measurement period / exponential smoothing time
2352 constant. This must be strictly greater than zero, because zero leads to
2353 run-time division errors. */
2355 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2356 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2358 return ratelimit_error(log_msgptr,
2359 "\"%s\" is not a time value", sender_rate_period);
2361 /* By default we are counting one of something, but the per_rcpt,
2362 per_byte, and count options can change this. */
2366 /* Parse the other options. */
2368 while ((ss = string_nextinlist(&arg, &sep, NULL, 0)))
2370 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2371 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2372 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2373 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2374 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2375 else if (strcmpic(ss, US"per_conn") == 0)
2377 RATE_SET(mode, PER_CONN);
2378 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2381 else if (strcmpic(ss, US"per_mail") == 0)
2383 RATE_SET(mode, PER_MAIL);
2384 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2386 else if (strcmpic(ss, US"per_rcpt") == 0)
2388 /* If we are running in the RCPT ACL, then we'll count the recipients
2389 one by one, but if we are running when we have accumulated the whole
2390 list then we'll add them all in one batch. */
2391 if (where == ACL_WHERE_RCPT)
2392 RATE_SET(mode, PER_RCPT);
2393 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2394 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2395 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2396 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2398 else if (strcmpic(ss, US"per_byte") == 0)
2400 /* If we have not yet received the message data and there was no SIZE
2401 declaration on the MAIL command, then it's safe to just use a value of
2402 zero and let the recorded rate decay as if nothing happened. */
2403 RATE_SET(mode, PER_MAIL);
2404 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2405 else count = message_size < 0 ? 0.0 : (double)message_size;
2407 else if (strcmpic(ss, US"per_addr") == 0)
2409 RATE_SET(mode, PER_RCPT);
2410 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2411 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2413 else if (strncmpic(ss, US"count=", 6) == 0)
2416 count = Ustrtod(ss+6, &e);
2417 if (count < 0.0 || *e != '\0')
2418 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2420 else if (strncmpic(ss, US"unique=", 7) == 0)
2421 unique = string_copy(ss + 7);
2423 key = string_copy(ss);
2425 key = string_sprintf("%s/%s", key, ss);
2428 /* Sanity check. When the badacl flag is set the update mode must either
2429 be readonly (which is the default if it is omitted) or, for backwards
2430 compatibility, a combination of noupdate and strict or leaky. */
2432 if (mode == RATE_PER_CLASH)
2433 return ratelimit_error(log_msgptr, "conflicting per_* options");
2434 if (leaky + strict + readonly > 1)
2435 return ratelimit_error(log_msgptr, "conflicting update modes");
2436 if (badacl && (leaky || strict) && !noupdate)
2437 return ratelimit_error(log_msgptr,
2438 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2439 ratelimit_option_string[mode], acl_wherenames[where]);
2441 /* Set the default values of any unset options. In readonly mode we
2442 perform the rate computation without any increment so that its value
2443 decays to eventually allow over-limit senders through. */
2445 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2446 if (badacl) readonly = TRUE;
2447 if (readonly) count = 0.0;
2448 if (!strict && !readonly) leaky = TRUE;
2449 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2451 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2452 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2453 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2454 are added to the key because they alter the meaning of the stored data. */
2457 key = !sender_host_address ? US"" : sender_host_address;
2459 key = string_sprintf("%s/%s/%s%s",
2461 ratelimit_option_string[mode],
2462 unique == NULL ? "" : "unique/",
2466 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2468 /* See if we have already computed the rate by looking in the relevant tree.
2469 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2470 pool so that they survive across resets. In readonly mode we only remember the
2471 result for the rest of this command in case a later command changes it. After
2472 this bit of logic the code is independent of the per_* mode. */
2474 old_pool = store_pool;
2477 anchor = &ratelimiters_cmd;
2481 anchor = &ratelimiters_conn;
2482 store_pool = POOL_PERM;
2486 case RATE_PER_ALLRCPTS:
2487 anchor = &ratelimiters_mail;
2492 anchor = &ratelimiters_cmd;
2495 anchor = NULL; /* silence an "unused" complaint */
2496 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2497 "internal ACL error: unknown ratelimit mode %d", mode);
2501 if ((t = tree_search(*anchor, key)))
2504 /* The following few lines duplicate some of the code below. */
2505 rc = (dbd->rate < limit)? FAIL : OK;
2506 store_pool = old_pool;
2507 sender_rate = string_sprintf("%.1f", dbd->rate);
2509 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2513 /* We aren't using a pre-computed rate, so get a previously recorded rate
2514 from the database, which will be updated and written back if required. */
2516 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE, TRUE)))
2518 store_pool = old_pool;
2520 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2521 *log_msgptr = US"ratelimit database not available";
2524 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2527 gettimeofday(&tv, NULL);
2531 /* Locate the basic ratelimit block inside the DB data. */
2532 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2535 /* Forget the old Bloom filter if it is too old, so that we count each
2536 repeating event once per period. We don't simply clear and re-use the old
2537 filter because we want its size to change if the limit changes. Note that
2538 we keep the dbd pointer for copying the rate into the new data block. */
2540 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2542 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2548 if(unique && dbdb_size < sizeof(*dbdb))
2550 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2555 /* Allocate a new data block if the database lookup failed
2556 or the Bloom filter passed its age limit. */
2562 /* No Bloom filter. This basic ratelimit block is initialized below. */
2563 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2564 dbdb_size = sizeof(*dbd);
2565 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2570 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2572 /* See the long comment below for an explanation of the magic number 2.
2573 The filter has a minimum size in case the rate limit is very small;
2574 this is determined by the definition of dbdata_ratelimit_unique. */
2576 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2577 if (extra < 0) extra = 0;
2578 dbdb_size = sizeof(*dbdb) + extra;
2579 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2580 dbdb->bloom_epoch = tv.tv_sec;
2581 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2582 memset(dbdb->bloom, 0, dbdb->bloom_size);
2584 /* Preserve any basic ratelimit data (which is our longer-term memory)
2585 by copying it from the discarded block. */
2595 /* If we are counting unique events, find out if this event is new or not.
2596 If the client repeats the event during the current period then it should be
2597 counted. We skip this code in readonly mode for efficiency, because any
2598 changes to the filter will be discarded and because count is already set to
2601 if (unique && !readonly)
2603 /* We identify unique events using a Bloom filter. (You can find my
2604 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2605 With the per_addr option, an "event" is a recipient address, though the
2606 user can use the unique option to define their own events. We only count
2607 an event if we have not seen it before.
2609 We size the filter according to the rate limit, which (in leaky mode)
2610 is the limit on the population of the filter. We allow 16 bits of space
2611 per entry (see the construction code above) and we set (up to) 8 of them
2612 when inserting an element (see the loop below). The probability of a false
2613 positive (an event we have not seen before but which we fail to count) is
2617 allzero = exp(-numhash * pop / size)
2618 = exp(-0.5 * pop / limit)
2619 fpr = pow(1 - allzero, numhash)
2621 For senders at the limit the fpr is 0.06% or 1 in 1700
2622 and for senders at half the limit it is 0.0006% or 1 in 170000
2624 In strict mode the Bloom filter can fill up beyond the normal limit, in
2625 which case the false positive rate will rise. This means that the
2626 measured rate for very fast senders can bogusly drop off after a while.
2628 At twice the limit, the fpr is 2.5% or 1 in 40
2629 At four times the limit, it is 31% or 1 in 3.2
2631 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2632 decay below the limit, and if this is more than one then the Bloom filter
2633 will be discarded before the decay gets that far. The false positive rate
2634 at this threshold is 9.3% or 1 in 10.7. */
2637 unsigned n, hash, hinc;
2641 /* Instead of using eight independent hash values, we combine two values
2642 using the formula h1 + n * h2. This does not harm the Bloom filter's
2643 performance, and means the amount of hash we need is independent of the
2644 number of bits we set in the filter. */
2646 md5_start(&md5info);
2647 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2648 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2649 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2651 /* Scan the bits corresponding to this event. A zero bit means we have
2652 not seen it before. Ensure all bits are set to record this event. */
2654 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2657 for (n = 0; n < 8; n++, hash += hinc)
2659 int bit = 1 << (hash % 8);
2660 int byte = (hash / 8) % dbdb->bloom_size;
2661 if ((dbdb->bloom[byte] & bit) == 0)
2663 dbdb->bloom[byte] |= bit;
2668 /* If this event has occurred before, do not count it. */
2672 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2676 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2679 /* If there was no previous ratelimit data block for this key, initialize
2680 the new one, otherwise update the block from the database. The initial rate
2681 is what would be computed by the code below for an infinite interval. */
2685 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2687 dbd->time_stamp = tv.tv_sec;
2688 dbd->time_usec = tv.tv_usec;
2693 /* The smoothed rate is computed using an exponentially weighted moving
2694 average adjusted for variable sampling intervals. The standard EWMA for
2695 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2696 where f() is the measured value and f'() is the smoothed value.
2698 Old data decays out of the smoothed value exponentially, such that data n
2699 samples old is multiplied by a^n. The exponential decay time constant p
2700 is defined such that data p samples old is multiplied by 1/e, which means
2701 that a = exp(-1/p). We can maintain the same time constant for a variable
2702 sampling interval i by using a = exp(-i/p).
2704 The rate we are measuring is messages per period, suitable for directly
2705 comparing with the limit. The average rate between now and the previous
2706 message is period / interval, which we feed into the EWMA as the sample.
2708 It turns out that the number of messages required for the smoothed rate
2709 to reach the limit when they are sent in a burst is equal to the limit.
2710 This can be seen by analysing the value of the smoothed rate after N
2711 messages sent at even intervals. Let k = (1 - a) * p/i
2713 rate_1 = (1 - a) * p/i + a * rate_0
2715 rate_2 = k + a * rate_1
2716 = k + a * k + a^2 * rate_0
2717 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2718 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2719 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2720 = rate_0 * a^N + p/i * (1 - a^N)
2722 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2724 rate_N = p/i + (rate_0 - p/i) * a^N
2725 a^N = (rate_N - p/i) / (rate_0 - p/i)
2726 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2727 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2729 Numerical analysis of the above equation, setting the computed rate to
2730 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2731 rates, p/i, the number of messages N = limit. So limit serves as both the
2732 maximum rate measured in messages per period, and the maximum number of
2733 messages that can be sent in a fast burst. */
2735 double this_time = (double)tv.tv_sec
2736 + (double)tv.tv_usec / 1000000.0;
2737 double prev_time = (double)dbd->time_stamp
2738 + (double)dbd->time_usec / 1000000.0;
2740 /* We must avoid division by zero, and deal gracefully with the clock going
2741 backwards. If we blunder ahead when time is in reverse then the computed
2742 rate will be bogus. To be safe we clamp interval to a very small number. */
2744 double interval = this_time - prev_time <= 0.0 ? 1e-9
2745 : this_time - prev_time;
2747 double i_over_p = interval / period;
2748 double a = exp(-i_over_p);
2750 /* Combine the instantaneous rate (period / interval) with the previous rate
2751 using the smoothing factor a. In order to measure sized events, multiply the
2752 instantaneous rate by the count of bytes or recipients etc. */
2754 dbd->time_stamp = tv.tv_sec;
2755 dbd->time_usec = tv.tv_usec;
2756 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2758 /* When events are very widely spaced the computed rate tends towards zero.
2759 Although this is accurate it turns out not to be useful for our purposes,
2760 especially when the first event after a long silence is the start of a spam
2761 run. A more useful model is that the rate for an isolated event should be the
2762 size of the event per the period size, ignoring the lack of events outside
2763 the current period and regardless of where the event falls in the period. So,
2764 if the interval was so long that the calculated rate is unhelpfully small, we
2765 re-initialize the rate. In the absence of higher-rate bursts, the condition
2766 below is true if the interval is greater than the period. */
2768 if (dbd->rate < count) dbd->rate = count;
2771 /* Clients sending at the limit are considered to be over the limit.
2772 This matters for edge cases such as a limit of zero, when the client
2773 should be completely blocked. */
2775 rc = dbd->rate < limit ? FAIL : OK;
2777 /* Update the state if the rate is low or if we are being strict. If we
2778 are in leaky mode and the sender's rate is too high, we do not update
2779 the recorded rate in order to avoid an over-aggressive sender's retry
2780 rate preventing them from getting any email through. If readonly is set,
2781 neither leaky nor strict are set, so we do not do any updates. */
2783 if ((rc == FAIL && leaky) || strict)
2785 dbfn_write(dbm, key, dbdb, dbdb_size);
2786 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2790 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2791 readonly? "readonly mode" : "over the limit, but leaky");
2796 /* Store the result in the tree for future reference. Take the taint status
2797 from the key for consistency even though it's unlikely we'll ever expand this. */
2799 t = store_get(sizeof(tree_node) + Ustrlen(key), is_tainted(key));
2801 Ustrcpy(t->name, key);
2802 (void)tree_insertnode(anchor, t);
2804 /* We create the formatted version of the sender's rate very late in
2805 order to ensure that it is done using the correct storage pool. */
2807 store_pool = old_pool;
2808 sender_rate = string_sprintf("%.1f", dbd->rate);
2811 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2818 /*************************************************
2819 * The udpsend ACL modifier *
2820 *************************************************/
2822 /* Called by acl_check_condition() below.
2825 arg the option string for udpsend=
2826 log_msgptr for error messages
2828 Returns: OK - Completed.
2829 DEFER - Problem with DNS lookup.
2830 ERROR - Syntax error in options.
2834 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2846 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2847 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2851 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2856 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2861 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2864 portnum = Ustrtol(portstr, &portend, 10);
2865 if (*portend != '\0')
2867 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2871 /* Make a single-item host list. */
2872 h = store_get(sizeof(host_item), FALSE);
2873 memset(h, 0, sizeof(host_item));
2878 if (string_is_ip_address(hostname, NULL))
2879 h->address = hostname, r = HOST_FOUND;
2881 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2882 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2884 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2889 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2891 /*XXX this could better use sendto */
2892 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2893 1, NULL, &errstr, NULL);
2894 if (r < 0) goto defer;
2896 r = send(s, arg, len, 0);
2899 errstr = US strerror(errno);
2907 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2912 debug_printf_indent("udpsend %d bytes\n", r);
2917 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2923 /*************************************************
2924 * Handle conditions/modifiers on an ACL item *
2925 *************************************************/
2927 /* Called from acl_check() below.
2931 cb ACL condition block - if NULL, result is OK
2932 where where called from
2933 addr the address being checked for RCPT, or NULL
2934 level the nesting level
2935 epp pointer to pass back TRUE if "endpass" encountered
2936 (applies only to "accept" and "discard")
2937 user_msgptr user message pointer
2938 log_msgptr log message pointer
2939 basic_errno pointer to where to put verify error
2941 Returns: OK - all conditions are met
2942 DISCARD - an "acl" condition returned DISCARD - only allowed
2943 for "accept" or "discard" verbs
2944 FAIL - at least one condition fails
2945 FAIL_DROP - an "acl" condition returned FAIL_DROP
2946 DEFER - can't tell at the moment (typically, lookup defer,
2947 but can be temporary callout problem)
2948 ERROR - ERROR from nested ACL or expansion failure or other
2953 acl_check_condition(int verb, acl_condition_block *cb, int where,
2954 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2955 uschar **log_msgptr, int *basic_errno)
2957 uschar *user_message = NULL;
2958 uschar *log_message = NULL;
2960 #ifdef WITH_CONTENT_SCAN
2964 for (; cb; cb = cb->next)
2969 /* The message and log_message items set up messages to be used in
2970 case of rejection. They are expanded later. */
2972 if (cb->type == ACLC_MESSAGE)
2974 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2975 user_message = cb->arg;
2979 if (cb->type == ACLC_LOG_MESSAGE)
2981 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2982 log_message = cb->arg;
2986 /* The endpass "condition" just sets a flag to show it occurred. This is
2987 checked at compile time to be on an "accept" or "discard" item. */
2989 if (cb->type == ACLC_ENDPASS)
2995 /* For other conditions and modifiers, the argument is expanded now for some
2996 of them, but not for all, because expansion happens down in some lower level
2997 checking functions in some cases. */
2999 if (!conditions[cb->type].expand_at_top)
3001 else if (!(arg = expand_string(cb->arg)))
3003 if (f.expand_string_forcedfail) continue;
3004 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
3005 cb->arg, expand_string_message);
3006 return f.search_find_defer ? DEFER : ERROR;
3009 /* Show condition, and expanded condition if it's different */
3014 debug_printf_indent("check %s%s %n",
3015 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
3016 conditions[cb->type].name, &lhswidth);
3018 if (cb->type == ACLC_SET)
3020 #ifndef DISABLE_DKIM
3021 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
3022 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3024 debug_printf("%s ", cb->u.varname);
3030 debug_printf("acl_%s ", cb->u.varname);
3031 lhswidth += 5 + Ustrlen(cb->u.varname);
3035 debug_printf("= %s\n", cb->arg);
3038 debug_printf("%.*s= %s\n", lhswidth,
3042 /* Check that this condition makes sense at this time */
3044 if ((conditions[cb->type].forbids & (1 << where)) != 0)
3046 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
3047 conditions[cb->type].is_modifier ? "use" : "test",
3048 conditions[cb->type].name, acl_wherenames[where]);
3052 /* Run the appropriate test for each condition, or take the appropriate
3053 action for the remaining modifiers. */
3057 case ACLC_ADD_HEADER:
3061 /* A nested ACL that returns "discard" makes sense only for an "accept" or
3065 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
3066 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
3068 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
3069 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
3075 case ACLC_AUTHENTICATED:
3076 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
3077 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
3080 #ifdef EXPERIMENTAL_BRIGHTMAIL
3081 case ACLC_BMI_OPTIN:
3083 int old_pool = store_pool;
3084 store_pool = POOL_PERM;
3085 bmi_current_optin = string_copy(arg);
3086 store_pool = old_pool;
3091 case ACLC_CONDITION:
3092 /* The true/false parsing here should be kept in sync with that used in
3093 expand.c when dealing with ECOND_BOOL so that we don't have too many
3094 different definitions of what can be a boolean. */
3096 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
3097 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
3098 rc = (Uatoi(arg) == 0)? FAIL : OK;
3100 rc = (strcmpic(arg, US"no") == 0 ||
3101 strcmpic(arg, US"false") == 0)? FAIL :
3102 (strcmpic(arg, US"yes") == 0 ||
3103 strcmpic(arg, US"true") == 0)? OK : DEFER;
3105 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3108 case ACLC_CONTINUE: /* Always succeeds */
3113 const uschar *p = NULL;
3114 control_type = decode_control(arg, &p, where, log_msgptr);
3116 /* Check if this control makes sense at this time */
3118 if (controls_list[control_type].forbids & (1 << where))
3120 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3121 controls_list[control_type].name, acl_wherenames[where]);
3125 switch(control_type)
3127 case CONTROL_AUTH_UNADVERTISED:
3128 f.allow_auth_unadvertised = TRUE;
3131 #ifdef EXPERIMENTAL_BRIGHTMAIL
3132 case CONTROL_BMI_RUN:
3137 #ifndef DISABLE_DKIM
3138 case CONTROL_DKIM_VERIFY:
3139 f.dkim_disable_verify = TRUE;
3140 # ifdef SUPPORT_DMARC
3141 /* Since DKIM was blocked, skip DMARC too */
3142 f.dmarc_disable_verify = TRUE;
3143 f.dmarc_enable_forensic = FALSE;
3148 #ifdef SUPPORT_DMARC
3149 case CONTROL_DMARC_VERIFY:
3150 f.dmarc_disable_verify = TRUE;
3153 case CONTROL_DMARC_FORENSIC:
3154 f.dmarc_enable_forensic = TRUE;
3161 int fd, af, level, optname, value;
3162 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3163 a socket; we can accept that, we'll just debug-log failures anyway. */
3164 fd = fileno(smtp_in);
3165 if ((af = ip_get_address_family(fd)) < 0)
3168 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3172 if (dscp_lookup(p+1, af, &level, &optname, &value))
3173 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3175 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3176 p+1, strerror(errno));
3180 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3184 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3190 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3198 case CONTROL_CASEFUL_LOCAL_PART:
3199 deliver_localpart = addr->cc_local_part;
3202 case CONTROL_CASELOWER_LOCAL_PART:
3203 deliver_localpart = addr->lc_local_part;
3206 case CONTROL_ENFORCE_SYNC:
3207 smtp_enforce_sync = TRUE;
3210 case CONTROL_NO_ENFORCE_SYNC:
3211 smtp_enforce_sync = FALSE;
3214 #ifdef WITH_CONTENT_SCAN
3215 case CONTROL_NO_MBOX_UNSPOOL:
3216 f.no_mbox_unspool = TRUE;
3220 case CONTROL_NO_MULTILINE:
3221 f.no_multiline_responses = TRUE;
3224 case CONTROL_NO_PIPELINING:
3225 f.pipelining_enable = FALSE;
3228 case CONTROL_NO_DELAY_FLUSH:
3229 f.disable_delay_flush = TRUE;
3232 case CONTROL_NO_CALLOUT_FLUSH:
3233 f.disable_callout_flush = TRUE;
3236 case CONTROL_FAKEREJECT:
3237 cancel_cutthrough_connection(TRUE, US"fakereject");
3238 case CONTROL_FAKEDEFER:
3239 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3242 const uschar *pp = p + 1;
3244 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3247 else /* Explicitly reset to default string */
3248 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).";
3251 case CONTROL_FREEZE:
3252 f.deliver_freeze = TRUE;
3253 deliver_frozen_at = time(NULL);
3254 freeze_tell = freeze_tell_config; /* Reset to configured value */
3255 if (Ustrncmp(p, "/no_tell", 8) == 0)
3262 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3265 cancel_cutthrough_connection(TRUE, US"item frozen");
3269 f.queue_only_policy = TRUE;
3270 if (Ustrcmp(p, "_only") == 0)
3272 else while (*p == '/')
3273 if (Ustrncmp(p, "/only", 5) == 0)
3274 { p += 5; f.queue_smtp = FALSE; }
3275 else if (Ustrncmp(p, "/first_pass_route", 17) == 0)
3276 { p += 17; f.queue_smtp = TRUE; }
3279 cancel_cutthrough_connection(TRUE, US"queueing forced");
3282 case CONTROL_SUBMISSION:
3283 originator_name = US"";
3284 f.submission_mode = TRUE;
3287 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3290 f.active_local_sender_retain = TRUE;
3291 f.active_local_from_check = FALSE;
3293 else if (Ustrncmp(p, "/domain=", 8) == 0)
3295 const uschar *pp = p + 8;
3296 while (*pp && *pp != '/') pp++;
3297 submission_domain = string_copyn(p+8, pp-p-8);
3300 /* The name= option must be last, because it swallows the rest of
3302 else if (Ustrncmp(p, "/name=", 6) == 0)
3304 const uschar *pp = p + 6;
3306 submission_name = parse_fix_phrase(p+6, pp-p-6);
3313 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3320 uschar * debug_tag = NULL;
3321 uschar * debug_opts = NULL;
3326 const uschar * pp = p+1;
3327 if (Ustrncmp(pp, "tag=", 4) == 0)
3329 for (pp += 4; *pp && *pp != '/';) pp++;
3330 debug_tag = string_copyn(p+5, pp-p-5);
3332 else if (Ustrncmp(pp, "opts=", 5) == 0)
3334 for (pp += 5; *pp && *pp != '/';) pp++;
3335 debug_opts = string_copyn(p+6, pp-p-6);
3337 else if (Ustrncmp(pp, "kill", 4) == 0)
3339 for (pp += 4; *pp && *pp != '/';) pp++;
3343 while (*pp && *pp != '/') pp++;
3348 debug_logging_stop();
3350 debug_logging_activate(debug_tag, debug_opts);
3354 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3355 f.suppress_local_fixups = TRUE;
3358 case CONTROL_CUTTHROUGH_DELIVERY:
3360 uschar * ignored = NULL;
3361 #ifndef DISABLE_PRDR
3366 /* Too hard to think about for now. We might in future cutthrough
3367 the case where both sides handle prdr and this-node prdr acl
3369 ignored = US"PRDR active";
3370 else if (f.deliver_freeze)
3371 ignored = US"frozen";
3372 else if (f.queue_only_policy)
3373 ignored = US"queue-only";
3374 else if (fake_response == FAIL)
3375 ignored = US"fakereject";
3376 else if (rcpt_count != 1)
3377 ignored = US"nonfirst rcpt";
3378 else if (cutthrough.delivery)
3379 ignored = US"repeated";
3380 else if (cutthrough.callout_hold_only)
3383 debug_printf_indent(" cutthrough request upgrades callout hold\n");
3384 cutthrough.callout_hold_only = FALSE;
3385 cutthrough.delivery = TRUE; /* control accepted */
3389 cutthrough.delivery = TRUE; /* control accepted */
3392 const uschar * pp = p+1;
3393 if (Ustrncmp(pp, "defer=", 6) == 0)
3396 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3397 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3400 while (*pp && *pp != '/') pp++;
3405 DEBUG(D_acl) if (ignored)
3406 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3411 case CONTROL_UTF8_DOWNCONVERT:
3416 message_utf8_downconvert = 1;
3417 addr->prop.utf8_downcvt = TRUE;
3418 addr->prop.utf8_downcvt_maybe = FALSE;
3424 message_utf8_downconvert = 0;
3425 addr->prop.utf8_downcvt = FALSE;
3426 addr->prop.utf8_downcvt_maybe = FALSE;
3430 if (p[1] == '-' && p[2] == '1')
3432 message_utf8_downconvert = -1;
3433 addr->prop.utf8_downcvt = FALSE;
3434 addr->prop.utf8_downcvt_maybe = TRUE;
3438 *log_msgptr = US"bad option value for control=utf8_downconvert";
3442 message_utf8_downconvert = 1;
3443 addr->prop.utf8_downcvt = TRUE;
3444 addr->prop.utf8_downcvt_maybe = FALSE;
3454 #ifdef EXPERIMENTAL_DCC
3457 /* Separate the regular expression and any optional parameters. */
3458 const uschar * list = arg;
3459 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
3460 /* Run the dcc backend. */
3461 rc = dcc_process(&ss);
3462 /* Modify return code based upon the existence of options. */
3463 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
3464 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3465 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3470 #ifdef WITH_CONTENT_SCAN
3472 rc = mime_decode(&arg);
3478 int delay = readconf_readtime(arg, 0, FALSE);
3481 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3482 "modifier: \"%s\" is not a time value", arg);
3487 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3492 debug_printf_indent("delay skipped in -bh checking mode\n");
3495 /* NOTE 1: Remember that we may be
3496 dealing with stdin/stdout here, in addition to TCP/IP connections.
3497 Also, delays may be specified for non-SMTP input, where smtp_out and
3498 smtp_in will be NULL. Whatever is done must work in all cases.
3500 NOTE 2: The added feature of flushing the output before a delay must
3501 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3506 if (smtp_out && !f.disable_delay_flush)
3509 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3515 p.fd = fileno(smtp_out);
3516 p.events = POLLRDHUP;
3519 if (poll(&p, n, delay*1000) > 0)
3520 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3523 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3524 TCP/IP connection has gone away without reading from it. This means
3525 that we cannot shorten the delay below if the client goes away,
3526 because we cannot discover that the client has closed its end of the
3527 connection. (The connection is actually in a half-closed state,
3528 waiting for the server to close its end.) It would be nice to be able
3529 to detect this state, so that the Exim process is not held up
3530 unnecessarily. However, it seems that we can't. The poll() function
3531 does not do the right thing, and in any case it is not always
3534 while (delay > 0) delay = sleep(delay);
3541 #ifndef DISABLE_DKIM
3542 case ACLC_DKIM_SIGNER:
3543 if (dkim_cur_signer)
3544 rc = match_isinlist(dkim_cur_signer,
3545 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3550 case ACLC_DKIM_STATUS:
3551 rc = match_isinlist(dkim_verify_status,
3552 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3556 #ifdef SUPPORT_DMARC
3557 case ACLC_DMARC_STATUS:
3558 if (!f.dmarc_has_been_checked)
3560 f.dmarc_has_been_checked = TRUE;
3561 /* used long way of dmarc_exim_expand_query() in case we need more
3562 * view into the process in the future. */
3563 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3564 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3569 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3573 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3574 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3577 /* The value in tls_cipher is the full cipher name, for example,
3578 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3579 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3580 what may in practice come out of the SSL library - which at the time of
3581 writing is poorly documented. */
3583 case ACLC_ENCRYPTED:
3584 if (tls_in.cipher == NULL) rc = FAIL; else
3586 uschar *endcipher = NULL;
3587 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3588 if (!cipher) cipher = tls_in.cipher; else
3590 endcipher = Ustrchr(++cipher, ':');
3591 if (endcipher) *endcipher = 0;
3593 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3594 if (endcipher) *endcipher = ':';
3598 /* Use verify_check_this_host() instead of verify_check_host() so that
3599 we can pass over &host_data to catch any looked up data. Once it has been
3600 set, it retains its value so that it's still there if another ACL verb
3601 comes through here and uses the cache. However, we must put it into
3602 permanent store in case it is also expected to be used in a subsequent
3603 message in the same SMTP connection. */
3606 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3607 sender_host_address ? sender_host_address : US"", CUSS &host_data);
3608 if (rc == DEFER) *log_msgptr = search_error_message;
3609 if (host_data) host_data = string_copy_perm(host_data, TRUE);
3612 case ACLC_LOCAL_PARTS:
3613 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3614 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3615 CUSS &deliver_localpart_data);
3618 case ACLC_LOG_REJECT_TARGET:
3622 const uschar *s = arg;
3624 while ((ss = string_nextinlist(&s, &sep, NULL, 0)))
3626 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3627 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3628 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3631 logbits |= LOG_MAIN|LOG_REJECT;
3632 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3633 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3636 log_reject_target = logbits;
3643 const uschar *s = arg;
3649 if (Ustrncmp(s, "main", 4) == 0)
3650 { logbits |= LOG_MAIN; s += 4; }
3651 else if (Ustrncmp(s, "panic", 5) == 0)
3652 { logbits |= LOG_PANIC; s += 5; }
3653 else if (Ustrncmp(s, "reject", 6) == 0)
3654 { logbits |= LOG_REJECT; s += 6; }
3657 logbits = LOG_MAIN|LOG_PANIC;
3658 s = string_sprintf(":unknown log name in \"%s\" in "
3659 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3665 while (isspace(*s)) s++;
3667 if (logbits == 0) logbits = LOG_MAIN;
3668 log_write(0, logbits, "%s", string_printing(s));
3672 #ifdef WITH_CONTENT_SCAN
3673 case ACLC_MALWARE: /* Run the malware backend. */
3675 /* Separate the regular expression and any optional parameters. */
3676 const uschar * list = arg;
3677 uschar * ss = string_nextinlist(&list, &sep, NULL, 0);
3679 BOOL defer_ok = FALSE;
3682 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3683 if (strcmpic(opt, US"defer_ok") == 0)
3685 else if ( strncmpic(opt, US"tmo=", 4) == 0
3686 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3689 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3693 rc = malware(ss, timeout);
3694 if (rc == DEFER && defer_ok)
3695 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3699 case ACLC_MIME_REGEX:
3700 rc = mime_regex(&arg);
3707 if (m = is_tainted2(arg, 0, "Tainted name '%s' for queue not permitted", arg))
3712 if (Ustrchr(arg, '/'))
3714 *log_msgptr = string_sprintf(
3715 "Directory separator not permitted in queue name: '%s'", arg);
3718 queue_name = string_copy_perm(arg, FALSE);
3722 case ACLC_RATELIMIT:
3723 rc = acl_ratelimit(arg, where, log_msgptr);
3726 case ACLC_RECIPIENTS:
3727 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3728 CUSS &recipient_data);
3731 #ifdef WITH_CONTENT_SCAN
3737 case ACLC_REMOVE_HEADER:
3738 setup_remove_header(arg);
3741 case ACLC_SENDER_DOMAINS:
3744 sdomain = Ustrrchr(sender_address, '@');
3745 sdomain = sdomain ? sdomain + 1 : US"";
3746 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3747 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3752 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3753 sender_address_cache, -1, 0, CUSS &sender_data);
3756 /* Connection variables must persist forever; message variables not */
3760 int old_pool = store_pool;
3761 if ( cb->u.varname[0] != 'm'
3762 #ifndef DISABLE_EVENT
3763 || event_name /* An event is being delivered */
3766 store_pool = POOL_PERM;
3767 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3768 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3769 dkim_verify_status = string_copy(arg);
3770 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3771 dkim_verify_reason = string_copy(arg);
3774 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3775 store_pool = old_pool;
3779 #ifdef WITH_CONTENT_SCAN
3782 /* Separate the regular expression and any optional parameters. */
3783 const uschar * list = arg;
3784 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
3786 rc = spam(CUSS &ss);
3787 /* Modify return code based upon the existence of options. */
3788 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
3789 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3790 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3797 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3799 case ACLC_SPF_GUESS:
3800 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3805 rc = acl_udpsend(arg, log_msgptr);
3808 /* If the verb is WARN, discard any user message from verification, because
3809 such messages are SMTP responses, not header additions. The latter come
3810 only from explicit "message" modifiers. However, put the user message into
3811 $acl_verify_message so it can be used in subsequent conditions or modifiers
3812 (until something changes it). */
3815 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3817 acl_verify_message = *user_msgptr;
3818 if (verb == ACL_WARN) *user_msgptr = NULL;
3822 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3823 "condition %d", cb->type);
3827 /* If a condition was negated, invert OK/FAIL. */
3829 if (!conditions[cb->type].is_modifier && cb->u.negated)
3830 if (rc == OK) rc = FAIL;
3831 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3833 if (rc != OK) break; /* Conditions loop */
3837 /* If the result is the one for which "message" and/or "log_message" are used,
3838 handle the values of these modifiers. If there isn't a log message set, we make
3839 it the same as the user message.
3841 "message" is a user message that will be included in an SMTP response. Unless
3842 it is empty, it overrides any previously set user message.
3844 "log_message" is a non-user message, and it adds to any existing non-user
3845 message that is already set.
3847 Most verbs have but a single return for which the messages are relevant, but
3848 for "discard", it's useful to have the log message both when it succeeds and
3849 when it fails. For "accept", the message is used in the OK case if there is no
3850 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3853 if (*epp && rc == OK) user_message = NULL;
3855 if ((BIT(rc) & msgcond[verb]) != 0)
3858 uschar *old_user_msgptr = *user_msgptr;
3859 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3861 /* If the verb is "warn", messages generated by conditions (verification or
3862 nested ACLs) are always discarded. This also happens for acceptance verbs
3863 when they actually do accept. Only messages specified at this level are used.
3864 However, the value of an existing message is available in $acl_verify_message
3865 during expansions. */
3867 if (verb == ACL_WARN ||
3868 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3869 *log_msgptr = *user_msgptr = NULL;
3873 acl_verify_message = old_user_msgptr;
3874 expmessage = expand_string(user_message);
3877 if (!f.expand_string_forcedfail)
3878 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3879 user_message, expand_string_message);
3881 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3886 acl_verify_message = old_log_msgptr;
3887 expmessage = expand_string(log_message);
3890 if (!f.expand_string_forcedfail)
3891 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3892 log_message, expand_string_message);
3894 else if (expmessage[0] != 0)
3896 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3897 string_sprintf("%s: %s", expmessage, *log_msgptr);
3901 /* If no log message, default it to the user message */
3903 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3906 acl_verify_message = NULL;
3914 /*************************************************
3915 * Get line from a literal ACL *
3916 *************************************************/
3918 /* This function is passed to acl_read() in order to extract individual lines
3919 of a literal ACL, which we access via static pointers. We can destroy the
3920 contents because this is called only once (the compiled ACL is remembered).
3922 This code is intended to treat the data in the same way as lines in the main
3923 Exim configuration file. That is:
3925 . Leading spaces are ignored.
3927 . A \ at the end of a line is a continuation - trailing spaces after the \
3928 are permitted (this is because I don't believe in making invisible things
3929 significant). Leading spaces on the continued part of a line are ignored.
3931 . Physical lines starting (significantly) with # are totally ignored, and
3932 may appear within a sequence of backslash-continued lines.
3934 . Blank lines are ignored, but will end a sequence of continuations.
3937 Returns: a pointer to the next line
3941 static uschar *acl_text; /* Current pointer in the text */
3942 static uschar *acl_text_end; /* Points one past the terminating '0' */
3950 /* This loop handles leading blank lines and comments. */
3954 Uskip_whitespace(&acl_text); /* Leading spaces/empty lines */
3955 if (!*acl_text) return NULL; /* No more data */
3956 yield = acl_text; /* Potential data line */
3958 while (*acl_text && *acl_text != '\n') acl_text++;
3960 /* If we hit the end before a newline, we have the whole logical line. If
3961 it's a comment, there's no more data to be given. Otherwise, yield it. */
3963 if (!*acl_text) return *yield == '#' ? NULL : yield;
3965 /* After reaching a newline, end this loop if the physical line does not
3966 start with '#'. If it does, it's a comment, and the loop continues. */
3968 if (*yield != '#') break;
3971 /* This loop handles continuations. We know we have some real data, ending in
3972 newline. See if there is a continuation marker at the end (ignoring trailing
3973 white space). We know that *yield is not white space, so no need to test for
3974 cont > yield in the backwards scanning loop. */
3979 for (cont = acl_text - 1; isspace(*cont); cont--);
3981 /* If no continuation follows, we are done. Mark the end of the line and
3990 /* We have encountered a continuation. Skip over whitespace at the start of
3991 the next line, and indeed the whole of the next line or lines if they are
3996 while (*(++acl_text) == ' ' || *acl_text == '\t');
3997 if (*acl_text != '#') break;
3998 while (*(++acl_text) != 0 && *acl_text != '\n');
4001 /* We have the start of a continuation line. Move all the rest of the data
4002 to join onto the previous line, and then find its end. If the end is not a
4003 newline, we are done. Otherwise loop to look for another continuation. */
4005 memmove(cont, acl_text, acl_text_end - acl_text);
4006 acl_text_end -= acl_text - cont;
4008 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
4009 if (*acl_text == 0) return yield;
4012 /* Control does not reach here */
4019 /*************************************************
4020 * Check access using an ACL *
4021 *************************************************/
4023 /* This function is called from address_check. It may recurse via
4024 acl_check_condition() - hence the use of a level to stop looping. The ACL is
4025 passed as a string which is expanded. A forced failure implies no access check
4026 is required. If the result is a single word, it is taken as the name of an ACL
4027 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
4028 text, complete with newlines, and parsed as such. In both cases, the ACL check
4029 is then run. This function uses an auxiliary function for acl_read() to call
4030 for reading individual lines of a literal ACL. This is acl_getline(), which
4031 appears immediately above.
4034 where where called from
4035 addr address item when called from RCPT; otherwise NULL
4036 s the input string; NULL is the same as an empty ACL => DENY
4037 user_msgptr where to put a user error (for SMTP response)
4038 log_msgptr where to put a logging message (not for SMTP response)
4040 Returns: OK access is granted
4041 DISCARD access is apparently granted...
4042 FAIL access is denied
4043 FAIL_DROP access is denied; drop the connection
4044 DEFER can't tell at the moment
4049 acl_check_internal(int where, address_item *addr, uschar *s,
4050 uschar **user_msgptr, uschar **log_msgptr)
4053 acl_block *acl = NULL;
4054 uschar *acl_name = US"inline ACL";
4057 /* Catch configuration loops */
4061 *log_msgptr = US"ACL nested too deep: possible loop";
4067 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
4071 /* At top level, we expand the incoming string. At lower levels, it has already
4072 been expanded as part of condition processing. */
4076 if (!(ss = expand_string(s)))
4078 if (f.expand_string_forcedfail) return OK;
4079 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
4080 expand_string_message);
4086 while (isspace(*ss)) ss++;
4088 /* If we can't find a named ACL, the default is to parse it as an inline one.
4089 (Unless it begins with a slash; non-existent files give rise to an error.) */
4093 if ( !f.running_in_test_harness
4094 && is_tainted2(acl_text, LOG_MAIN|LOG_PANIC,
4095 "Tainted ACL text \"%s\"", acl_text))
4097 /* Avoid leaking info to an attacker */
4098 *log_msgptr = US"internal configuration error";
4102 /* Handle the case of a string that does not contain any spaces. Look for a
4103 named ACL among those read from the configuration, or a previously read file.
4104 It is possible that the pointer to the ACL is NULL if the configuration
4105 contains a name with no data. If not found, and the text begins with '/',
4106 read an ACL from a file, and save it so it can be re-used. */
4108 if (Ustrchr(ss, ' ') == NULL)
4110 tree_node * t = tree_search(acl_anchor, ss);
4113 if (!(acl = (acl_block *)(t->data.ptr)))
4115 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
4118 acl_name = string_sprintf("ACL \"%s\"", ss);
4119 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4122 else if (*ss == '/')
4124 struct stat statbuf;
4125 if (is_tainted2(ss, LOG_MAIN|LOG_PANIC, "Tainted ACL file name '%s'", ss))
4127 /* Avoid leaking info to an attacker */
4128 *log_msgptr = US"internal configuration error";
4131 if ((fd = Uopen(ss, O_RDONLY, 0)) < 0)
4133 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4137 if (fstat(fd, &statbuf) != 0)
4139 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4144 /* If the string being used as a filename is tainted, so is the file content */
4145 acl_text = store_get(statbuf.st_size + 1, is_tainted(ss));
4146 acl_text_end = acl_text + statbuf.st_size + 1;
4148 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4150 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4151 ss, strerror(errno));
4154 acl_text[statbuf.st_size] = 0;
4157 acl_name = string_sprintf("ACL \"%s\"", ss);
4158 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4162 /* Parse an ACL that is still in text form. If it came from a file, remember it
4163 in the ACL tree, having read it into the POOL_PERM store pool so that it
4164 persists between multiple messages. */
4168 int old_pool = store_pool;
4169 if (fd >= 0) store_pool = POOL_PERM;
4170 acl = acl_read(acl_getline, log_msgptr);
4171 store_pool = old_pool;
4172 if (!acl && *log_msgptr) return ERROR;
4175 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss), is_tainted(ss));
4176 Ustrcpy(t->name, ss);
4178 (void)tree_insertnode(&acl_anchor, t);
4182 /* Now we have an ACL to use. It's possible it may be NULL. */
4187 int basic_errno = 0;
4188 BOOL endpass_seen = FALSE;
4189 BOOL acl_quit_check = acl_level == 0
4190 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4192 *log_msgptr = *user_msgptr = NULL;
4193 f.acl_temp_details = FALSE;
4195 HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n",
4196 verbs[acl->verb], acl->srcfile, acl->srcline);
4198 /* Clear out any search error message from a previous check before testing
4201 search_error_message = NULL;
4202 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4203 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4205 /* Handle special returns: DEFER causes a return except on a WARN verb;
4206 ERROR always causes a return. */
4211 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n",
4212 verbs[acl->verb], acl_name);
4213 if (basic_errno != ERRNO_CALLOUTDEFER)
4215 if (search_error_message != NULL && *search_error_message != 0)
4216 *log_msgptr = search_error_message;
4217 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4220 f.acl_temp_details = TRUE;
4221 if (acl->verb != ACL_WARN) return DEFER;
4224 default: /* Paranoia */
4226 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n",
4227 verbs[acl->verb], acl_name);
4231 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4232 verbs[acl->verb], acl_name);
4236 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n",
4237 verbs[acl->verb], acl_name);
4240 /* DISCARD and DROP can happen only from a nested ACL condition, and
4241 DISCARD can happen only for an "accept" or "discard" verb. */
4244 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4245 verbs[acl->verb], acl_name);
4249 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4250 verbs[acl->verb], acl_name);
4254 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4255 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4256 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4261 if (cond == OK || cond == DISCARD)
4263 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4268 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4276 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4277 if (acl_quit_check) goto badquit;
4278 f.acl_temp_details = TRUE;
4286 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4287 if (acl_quit_check) goto badquit;
4293 if (cond == OK || cond == DISCARD)
4295 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4296 if (acl_quit_check) goto badquit;
4302 debug_printf_indent("discard: endpass encountered - denying access\n");
4310 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4311 if (acl_quit_check) goto badquit;
4319 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4320 if (acl_quit_check) goto badquit;
4327 acl_warn(where, *user_msgptr, *log_msgptr);
4328 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4329 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4330 "condition test deferred%s%s", host_and_ident(TRUE),
4331 (*log_msgptr == NULL)? US"" : US": ",
4332 (*log_msgptr == NULL)? US"" : *log_msgptr);
4333 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4337 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4342 /* Pass to the next ACL item */
4347 /* We have reached the end of the ACL. This is an implicit DENY. */
4349 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4353 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4354 "('%s' verb used incorrectly)", verbs[acl->verb]);
4361 /* Same args as acl_check_internal() above, but the string s is
4362 the name of an ACL followed optionally by up to 9 space-separated arguments.
4363 The name and args are separately expanded. Args go into $acl_arg globals. */
4365 acl_check_wargs(int where, address_item *addr, const uschar *s,
4366 uschar **user_msgptr, uschar **log_msgptr)
4369 uschar * tmp_arg[9]; /* must match acl_arg[] */
4370 uschar * sav_arg[9]; /* must match acl_arg[] */
4376 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4379 for (i = 0; i < 9; i++)
4381 while (*s && isspace(*s)) s++;
4383 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4390 sav_narg = acl_narg;
4392 for (i = 0; i < acl_narg; i++)
4394 sav_arg[i] = acl_arg[i];
4395 acl_arg[i] = tmp_arg[i];
4399 sav_arg[i] = acl_arg[i];
4400 acl_arg[i++] = NULL;
4404 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4407 acl_narg = sav_narg;
4408 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4412 if (f.expand_string_forcedfail) return ERROR;
4413 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4414 tmp, expand_string_message);
4415 return f.search_find_defer ? DEFER : ERROR;
4420 /*************************************************
4421 * Check access using an ACL *
4422 *************************************************/
4424 /* Alternate interface for ACL, used by expansions */
4426 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4429 address_item *addr = NULL;
4432 *user_msgptr = *log_msgptr = NULL;
4433 sender_verified_failed = NULL;
4434 ratelimiters_cmd = NULL;
4435 log_reject_target = LOG_MAIN|LOG_REJECT;
4437 if (where == ACL_WHERE_RCPT)
4439 adb = address_defaults;
4441 addr->address = expand_string(US"$local_part@$domain");
4442 addr->domain = deliver_domain;
4443 addr->local_part = deliver_localpart;
4444 addr->cc_local_part = deliver_localpart;
4445 addr->lc_local_part = deliver_localpart;
4449 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4456 /* This is the external interface for ACL checks. It sets up an address and the
4457 expansions for $domain and $local_part when called after RCPT, then calls
4458 acl_check_internal() to do the actual work.
4461 where ACL_WHERE_xxxx indicating where called from
4462 recipient RCPT address for RCPT check, else NULL
4463 s the input string; NULL is the same as an empty ACL => DENY
4464 user_msgptr where to put a user error (for SMTP response)
4465 log_msgptr where to put a logging message (not for SMTP response)
4467 Returns: OK access is granted by an ACCEPT verb
4468 DISCARD access is granted by a DISCARD verb
4469 FAIL access is denied
4470 FAIL_DROP access is denied; drop the connection
4471 DEFER can't tell at the moment
4474 int acl_where = ACL_WHERE_UNKNOWN;
4477 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4478 uschar **log_msgptr)
4482 address_item *addr = NULL;
4484 *user_msgptr = *log_msgptr = NULL;
4485 sender_verified_failed = NULL;
4486 ratelimiters_cmd = NULL;
4487 log_reject_target = LOG_MAIN|LOG_REJECT;
4489 #ifndef DISABLE_PRDR
4490 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4492 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4495 adb = address_defaults;
4497 addr->address = recipient;
4498 if (deliver_split_address(addr) == DEFER)
4500 *log_msgptr = US"defer in percent_hack_domains check";
4504 if ((addr->prop.utf8_msg = message_smtputf8))
4506 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4507 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4510 deliver_domain = addr->domain;
4511 deliver_localpart = addr->local_part;
4516 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4518 acl_where = ACL_WHERE_UNKNOWN;
4520 /* Cutthrough - if requested,
4521 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4522 and rcpt acl returned accept,
4523 and first recipient (cancel on any subsequents)
4524 open one now and run it up to RCPT acceptance.
4525 A failed verify should cancel cutthrough request,
4526 and will pass the fail to the originator.
4527 Initial implementation: dual-write to spool.
4528 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4530 Cease cutthrough copy on rxd final dot; do not send one.
4532 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4534 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4535 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4536 If temp-reject, close the conn (and keep the spooled copy).
4537 If conn-failure, no action (and keep the spooled copy).
4541 case ACL_WHERE_RCPT:
4542 #ifndef DISABLE_PRDR
4543 case ACL_WHERE_PRDR:
4546 if (f.host_checking_callout) /* -bhc mode */
4547 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4550 && cutthrough.delivery
4551 && rcpt_count > cutthrough.nrcpt
4554 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4555 if (cutthrough.defer_pass)
4557 uschar * s = addr->message;
4558 /* Horrid kludge to recover target's SMTP message */
4560 do --s; while (!isdigit(*s));
4561 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4562 f.acl_temp_details = TRUE;
4566 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4570 else HDEBUG(D_acl) if (cutthrough.delivery)
4571 if (rcpt_count <= cutthrough.nrcpt)
4572 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4574 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4577 case ACL_WHERE_PREDATA:
4579 cutthrough_predata();
4581 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4584 case ACL_WHERE_QUIT:
4585 case ACL_WHERE_NOTQUIT:
4586 /* Drop cutthrough conns, and drop heldopen verify conns if
4587 the previous was not DATA */
4590 smtp_connection_had[SMTP_HBUFF_PREV(SMTP_HBUFF_PREV(smtp_ch_index))];
4591 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4593 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4601 deliver_domain = deliver_localpart = deliver_address_data =
4602 deliver_domain_data = sender_address_data = NULL;
4604 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4605 ACL, which is really in the middle of an SMTP command. */
4609 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4611 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4612 "ACL", acl_wherenames[where]);
4618 /* A DROP response is not permitted from MAILAUTH */
4620 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4622 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4623 "ACL", acl_wherenames[where]);
4627 /* Before giving a response, take a look at the length of any user message, and
4628 split it up into multiple lines if possible. */
4630 *user_msgptr = string_split_message(*user_msgptr);
4631 if (fake_response != OK)
4632 fake_response_text = string_split_message(fake_response_text);
4638 /*************************************************
4639 * Create ACL variable *
4640 *************************************************/
4642 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4643 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4646 name pointer to the variable's name, starting with c or m
4648 Returns the pointer to variable's tree node
4652 acl_var_create(uschar * name)
4654 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4655 if (!(node = tree_search(*root, name)))
4657 node = store_get(sizeof(tree_node) + Ustrlen(name), is_tainted(name));
4658 Ustrcpy(node->name, name);
4659 (void)tree_insertnode(root, node);
4661 node->data.ptr = NULL;
4667 /*************************************************
4668 * Write an ACL variable in spool format *
4669 *************************************************/
4671 /* This function is used as a callback for tree_walk when writing variables to
4672 the spool file. To retain spool file compatibility, what is written is -aclc or
4673 -aclm followed by the rest of the name and the data length, space separated,
4674 then the value itself, starting on a new line, and terminated by an additional
4675 newline. When we had only numbered ACL variables, the first line might look
4676 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4680 name of the variable
4681 value of the variable
4682 ctx FILE pointer (as a void pointer)
4688 acl_var_write(uschar *name, uschar *value, void *ctx)
4690 FILE *f = (FILE *)ctx;
4691 if (is_tainted(value)) putc('-', f);
4692 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);
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