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;
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 user_msgptr = user_msgptr; /* stop compiler warning */
1191 /* Previous success */
1193 if (sender_host_name != NULL) return OK;
1195 /* Previous failure */
1197 if (host_lookup_failed)
1199 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1203 /* Need to do a lookup */
1206 debug_printf_indent("looking up host name to force name/address consistency check\n");
1208 if ((rc = host_name_lookup()) != OK)
1210 *log_msgptr = rc == DEFER
1211 ? US"host lookup deferred for reverse lookup check"
1212 : string_sprintf("host lookup failed for reverse lookup check%s",
1214 return rc; /* DEFER or FAIL */
1217 host_build_sender_fullhost();
1223 /*************************************************
1224 * Check client IP address matches CSA target *
1225 *************************************************/
1227 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1228 response for address records belonging to the CSA target hostname. The section
1229 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1230 If one of the addresses matches the client's IP address, then the client is
1231 authorized by CSA. If there are target IP addresses but none of them match
1232 then the client is using an unauthorized IP address. If there are no target IP
1233 addresses then the client cannot be using an authorized IP address. (This is
1234 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1237 dnsa the DNS answer block
1238 dnss a DNS scan block for us to use
1239 reset option specifying what portion to scan, as described above
1240 target the target hostname to use for matching RR names
1242 Returns: CSA_OK successfully authorized
1243 CSA_FAIL_MISMATCH addresses found but none matched
1244 CSA_FAIL_NOADDR no target addresses found
1248 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1251 int rc = CSA_FAIL_NOADDR;
1253 for (dns_record * rr = dns_next_rr(dnsa, dnss, reset);
1255 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1257 /* Check this is an address RR for the target hostname. */
1261 && rr->type != T_AAAA
1265 if (strcmpic(target, rr->name) != 0) continue;
1267 rc = CSA_FAIL_MISMATCH;
1269 /* Turn the target address RR into a list of textual IP addresses and scan
1270 the list. There may be more than one if it is an A6 RR. */
1272 for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next)
1274 /* If the client IP address matches the target IP address, it's good! */
1276 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1278 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1282 /* If we found some target addresses but none of them matched, the client is
1283 using an unauthorized IP address, otherwise the target has no authorized IP
1291 /*************************************************
1292 * Verify Client SMTP Authorization *
1293 *************************************************/
1295 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1296 to find the CSA SRV record corresponding to the domain argument, or
1297 $sender_helo_name if no argument is provided. It then checks that the
1298 client is authorized, and that its IP address corresponds to the SRV
1299 target's address by calling acl_verify_csa_address() above. The address
1300 should have been returned in the DNS response's ADDITIONAL section, but if
1301 not we perform another DNS lookup to get it.
1304 domain pointer to optional parameter following verify = csa
1306 Returns: CSA_UNKNOWN no valid CSA record found
1307 CSA_OK successfully authorized
1308 CSA_FAIL_* client is definitely not authorized
1309 CSA_DEFER_* there was a DNS problem
1313 acl_verify_csa(const uschar *domain)
1316 const uschar *found;
1317 int priority, weight, port;
1318 dns_answer * dnsa = store_get_dns_answer();
1324 /* Work out the domain we are using for the CSA lookup. The default is the
1325 client's HELO domain. If the client has not said HELO, use its IP address
1326 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1328 while (isspace(*domain) && *domain != '\0') ++domain;
1329 if (*domain == '\0') domain = sender_helo_name;
1330 if (domain == NULL) domain = sender_host_address;
1331 if (sender_host_address == NULL) return CSA_UNKNOWN;
1333 /* If we have an address literal, strip off the framing ready for turning it
1334 into a domain. The framing consists of matched square brackets possibly
1335 containing a keyword and a colon before the actual IP address. */
1337 if (domain[0] == '[')
1339 const uschar *start = Ustrchr(domain, ':');
1340 if (start == NULL) start = domain;
1341 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1344 /* Turn domains that look like bare IP addresses into domains in the reverse
1345 DNS. This code also deals with address literals and $sender_host_address. It's
1346 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1347 address literals, but it's probably the most friendly thing to do. This is an
1348 extension to CSA, so we allow it to be turned off for proper conformance. */
1350 if (string_is_ip_address(domain, NULL) != 0)
1352 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1353 domain = dns_build_reverse(domain);
1356 /* Find out if we've already done the CSA check for this domain. If we have,
1357 return the same result again. Otherwise build a new cached result structure
1358 for this domain. The name is filled in now, and the value is filled in when
1359 we return from this function. */
1361 t = tree_search(csa_cache, domain);
1362 if (t != NULL) return t->data.val;
1364 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain), is_tainted(domain));
1365 Ustrcpy(t->name, domain);
1366 (void)tree_insertnode(&csa_cache, t);
1368 /* Now we are ready to do the actual DNS lookup(s). */
1371 switch (dns_special_lookup(dnsa, domain, T_CSA, &found))
1373 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1376 return t->data.val = CSA_DEFER_SRV;
1378 /* If we found nothing, the client's authorization is unknown. */
1382 return t->data.val = CSA_UNKNOWN;
1384 /* We got something! Go on to look at the reply in more detail. */
1390 /* Scan the reply for well-formed CSA SRV records. */
1392 for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1394 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1396 const uschar * p = rr->data;
1398 /* Extract the numerical SRV fields (p is incremented) */
1400 GETSHORT(priority, p);
1401 GETSHORT(weight, p);
1405 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1407 /* Check the CSA version number */
1409 if (priority != 1) continue;
1411 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1412 found by dns_special_lookup() is a parent of the one we asked for), we check
1413 the subdomain assertions in the port field. At the moment there's only one
1414 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1415 SRV records of their own. */
1417 if (Ustrcmp(found, domain) != 0)
1418 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1420 /* This CSA SRV record refers directly to our domain, so we check the value
1421 in the weight field to work out the domain's authorization. 0 and 1 are
1422 unauthorized; 3 means the client is authorized but we can't check the IP
1423 address in order to authenticate it, so we treat it as unknown; values
1424 greater than 3 are undefined. */
1426 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1428 if (weight > 2) continue;
1430 /* Weight == 2, which means the domain is authorized. We must check that the
1431 client's IP address is listed as one of the SRV target addresses. Save the
1432 target hostname then break to scan the additional data for its addresses. */
1434 (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, p,
1435 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1437 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1442 /* If we didn't break the loop then no appropriate records were found. */
1444 if (!rr) return t->data.val = CSA_UNKNOWN;
1446 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1447 A target of "." indicates there are no valid addresses, so the client cannot
1448 be authorized. (This is an odd configuration because weight=2 target=. is
1449 equivalent to weight=1, but we check for it in order to keep load off the
1450 root name servers.) Note that dn_expand() turns "." into "". */
1452 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1454 /* Scan the additional section of the CSA SRV reply for addresses belonging
1455 to the target. If the name server didn't return any additional data (e.g.
1456 because it does not fully support SRV records), we need to do another lookup
1457 to obtain the target addresses; otherwise we have a definitive result. */
1459 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ADDITIONAL, target);
1460 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1462 /* The DNS lookup type corresponds to the IP version used by the client. */
1465 if (Ustrchr(sender_host_address, ':') != NULL)
1468 #endif /* HAVE_IPV6 */
1472 lookup_dnssec_authenticated = NULL;
1473 switch (dns_lookup(dnsa, target, type, NULL))
1475 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1478 return t->data.val = CSA_DEFER_ADDR;
1480 /* If the query succeeded, scan the addresses and return the result. */
1483 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ANSWERS, target);
1484 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1485 /* else fall through */
1487 /* If the target has no IP addresses, the client cannot have an authorized
1488 IP address. However, if the target site uses A6 records (not AAAA records)
1489 we have to do yet another lookup in order to check them. */
1493 return t->data.val = CSA_FAIL_NOADDR;
1499 /*************************************************
1500 * Handle verification (address & other) *
1501 *************************************************/
1503 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1504 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1505 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1510 unsigned where_allowed; /* bitmap */
1511 BOOL no_options; /* Never has /option(s) following */
1512 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1514 static verify_type_t verify_type_list[] = {
1515 /* name value where no-opt opt-sep */
1516 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, (unsigned)~0, FALSE, 0 },
1517 { US"certificate", VERIFY_CERT, (unsigned)~0, TRUE, 0 },
1518 { US"helo", VERIFY_HELO, (unsigned)~0, TRUE, 0 },
1519 { US"csa", VERIFY_CSA, (unsigned)~0, FALSE, 0 },
1520 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1521 { US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1522 { US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1523 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1524 | ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1526 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1527 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1528 #ifdef EXPERIMENTAL_ARC
1529 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1534 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1535 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1536 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1537 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1543 BOOL has_option; /* Has =option(s) following */
1544 BOOL timeval; /* Has a time value */
1546 static callout_opt_t callout_opt_list[] = {
1547 /* name value flag has-opt has-time */
1548 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1549 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1550 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1551 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1552 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1553 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1554 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1555 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1556 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1557 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1558 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1559 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1560 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1566 v_period(const uschar * s, const uschar * arg, uschar ** log_msgptr)
1569 if ((period = readconf_readtime(s, 0, FALSE)) < 0)
1571 *log_msgptr = string_sprintf("bad time value in ACL condition "
1572 "\"verify %s\"", arg);
1579 /* This function implements the "verify" condition. It is called when
1580 encountered in any ACL, because some tests are almost always permitted. Some
1581 just don't make sense, and always fail (for example, an attempt to test a host
1582 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1585 where where called from
1586 addr the recipient address that the ACL is handling, or NULL
1587 arg the argument of "verify"
1588 user_msgptr pointer for user message
1589 log_msgptr pointer for log message
1590 basic_errno where to put verify errno
1592 Returns: OK verification condition succeeded
1593 FAIL verification failed
1594 DEFER there was a problem verifying
1599 acl_verify(int where, address_item *addr, const uschar *arg,
1600 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1604 int callout_overall = -1;
1605 int callout_connect = -1;
1606 int verify_options = 0;
1608 BOOL verify_header_sender = FALSE;
1609 BOOL defer_ok = FALSE;
1610 BOOL callout_defer_ok = FALSE;
1611 BOOL no_details = FALSE;
1612 BOOL success_on_redirect = FALSE;
1614 int quota_pos_cache = QUOTA_POS_DEFAULT, quota_neg_cache = QUOTA_NEG_DEFAULT;
1615 address_item *sender_vaddr = NULL;
1616 uschar *verify_sender_address = NULL;
1617 uschar *pm_mailfrom = NULL;
1618 uschar *se_mailfrom = NULL;
1620 /* Some of the verify items have slash-separated options; some do not. Diagnose
1621 an error if options are given for items that don't expect them.
1624 uschar *slash = Ustrchr(arg, '/');
1625 const uschar *list = arg;
1626 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
1629 if (!ss) goto BAD_VERIFY;
1631 /* Handle name/address consistency verification in a separate function. */
1633 for (vp = verify_type_list;
1634 CS vp < CS verify_type_list + sizeof(verify_type_list);
1637 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1638 : strcmpic (ss, vp->name) == 0)
1640 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1643 if (vp->no_options && slash)
1645 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1646 "(this verify item has no options)", arg);
1649 if (!(vp->where_allowed & BIT(where)))
1651 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1652 vp->name, acl_wherenames[where]);
1657 case VERIFY_REV_HOST_LKUP:
1658 if (!sender_host_address) return OK;
1659 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1660 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1661 if (strcmpic(ss, US"defer_ok") == 0)
1666 /* TLS certificate verification is done at STARTTLS time; here we just
1667 test whether it was successful or not. (This is for optional verification; for
1668 mandatory verification, the connection doesn't last this long.) */
1670 if (tls_in.certificate_verified) return OK;
1671 *user_msgptr = US"no verified certificate";
1675 /* We can test the result of optional HELO verification that might have
1676 occurred earlier. If not, we can attempt the verification now. */
1678 if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo();
1679 return f.helo_verified ? OK : FAIL;
1682 /* Do Client SMTP Authorization checks in a separate function, and turn the
1683 result code into user-friendly strings. */
1685 rc = acl_verify_csa(list);
1686 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1687 csa_reason_string[rc]);
1688 csa_status = csa_status_string[rc];
1689 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1690 return csa_return_code[rc];
1692 #ifdef EXPERIMENTAL_ARC
1694 { /* Do Authenticated Received Chain checks in a separate function. */
1695 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1699 if (!(arc_state = acl_verify_arc())) return DEFER;
1700 DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state,
1701 arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":"");
1703 if (!condlist) condlist = US"none:pass";
1704 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1705 if (Ustrcmp(arc_state, cond) == 0) return OK;
1710 case VERIFY_HDR_SYNTAX:
1711 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1712 a syntax error, we return details of the error to the sender if configured to
1713 send out full details. (But a "message" setting on the ACL can override, as
1716 rc = verify_check_headers(log_msgptr);
1717 if (rc != OK && *log_msgptr)
1718 if (smtp_return_error_details)
1719 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1721 acl_verify_message = *log_msgptr;
1724 case VERIFY_HDR_NAMES_ASCII:
1725 /* Check that all header names are true 7 bit strings
1726 See RFC 5322, 2.2. and RFC 6532, 3. */
1728 rc = verify_check_header_names_ascii(log_msgptr);
1729 if (rc != OK && smtp_return_error_details && *log_msgptr)
1730 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1733 case VERIFY_NOT_BLIND:
1734 /* Check that no recipient of this message is "blind", that is, every envelope
1735 recipient must be mentioned in either To: or Cc:. */
1737 BOOL case_sensitive = TRUE;
1739 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1740 if (strcmpic(ss, US"case_insensitive") == 0)
1741 case_sensitive = FALSE;
1744 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1745 "condition \"verify %s\"", ss, arg);
1749 if ((rc = verify_check_notblind(case_sensitive)) != OK)
1751 *log_msgptr = US"bcc recipient detected";
1752 if (smtp_return_error_details)
1753 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1758 /* The remaining verification tests check recipient and sender addresses,
1759 either from the envelope or from the header. There are a number of
1760 slash-separated options that are common to all of them. */
1762 case VERIFY_HDR_SNDR:
1763 verify_header_sender = TRUE;
1767 /* In the case of a sender, this can optionally be followed by an address to use
1768 in place of the actual sender (rare special-case requirement). */
1772 verify_sender_address = sender_address;
1775 while (isspace(*s)) s++;
1776 if (*s++ != '=') goto BAD_VERIFY;
1777 while (isspace(*s)) s++;
1778 verify_sender_address = string_copy(s);
1789 /* Remaining items are optional; they apply to sender and recipient
1790 verification, including "header sender" verification. */
1792 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1794 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1795 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1796 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1798 /* These two old options are left for backwards compatibility */
1800 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1802 callout_defer_ok = TRUE;
1803 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1806 else if (strcmpic(ss, US"check_postmaster") == 0)
1809 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1812 /* The callout option has a number of sub-options, comma separated */
1814 else if (strncmpic(ss, US"callout", 7) == 0)
1816 callout = CALLOUT_TIMEOUT_DEFAULT;
1819 while (isspace(*ss)) ss++;
1822 const uschar * sublist = ss;
1825 while (isspace(*sublist)) sublist++;
1826 for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); )
1829 double period = 1.0F;
1831 for (op= callout_opt_list; op->name; op++)
1832 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1835 verify_options |= op->flag;
1838 opt += Ustrlen(op->name);
1839 while (isspace(*opt)) opt++;
1842 *log_msgptr = string_sprintf("'=' expected after "
1843 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1846 while (isspace(*opt)) opt++;
1848 if (op->timeval && (period = v_period(opt, arg, log_msgptr)) < 0)
1853 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1854 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1855 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1856 case CALLOUT_MAILFROM:
1857 if (!verify_header_sender)
1859 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1860 "callout option only for verify=header_sender (detected in ACL "
1861 "condition \"%s\")", arg);
1864 se_mailfrom = string_copy(opt);
1866 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1867 case CALLOUT_MAXWAIT: callout_overall = period; break;
1868 case CALLOUT_CONNECT: callout_connect = period; break;
1869 case CALLOUT_TIME: callout = period; break;
1875 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1876 "ACL condition \"%s\"", arg);
1882 /* The quota option has sub-options, comma-separated */
1884 else if (strncmpic(ss, US"quota", 5) == 0)
1889 while (isspace(*ss)) ss++;
1892 const uschar * sublist = ss;
1896 while (isspace(*sublist)) sublist++;
1897 for (uschar * opt; opt = string_nextinlist(&sublist, &optsep, NULL, 0); )
1898 if (Ustrncmp(opt, "cachepos=", 9) == 0)
1899 if ((period = v_period(opt += 9, arg, log_msgptr)) < 0)
1902 quota_pos_cache = period;
1903 else if (Ustrncmp(opt, "cacheneg=", 9) == 0)
1904 if ((period = v_period(opt += 9, arg, log_msgptr)) < 0)
1907 quota_neg_cache = period;
1908 else if (Ustrcmp(opt, "no_cache") == 0)
1909 quota_pos_cache = quota_neg_cache = 0;
1914 /* Option not recognized */
1918 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1919 "condition \"verify %s\"", ss, arg);
1924 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1925 (vopt_callout_recipsender|vopt_callout_recippmaster))
1927 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1928 "for a recipient callout";
1932 /* Handle quota verification */
1935 if (vp->value != VERIFY_RCPT)
1937 *log_msgptr = US"can only verify quota of recipient";
1941 if ((rc = verify_quota_call(addr->address,
1942 quota_pos_cache, quota_neg_cache, log_msgptr)) != OK)
1944 *basic_errno = errno;
1945 if (smtp_return_error_details)
1947 if (!*user_msgptr && *log_msgptr)
1948 *user_msgptr = string_sprintf("Rejected after %s: %s",
1949 smtp_names[smtp_connection_had[smtp_ch_index-1]], *log_msgptr);
1950 if (rc == DEFER) f.acl_temp_details = TRUE;
1957 /* Handle sender-in-header verification. Default the user message to the log
1958 message if giving out verification details. */
1960 if (verify_header_sender)
1964 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1965 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1968 *basic_errno = verrno;
1969 if (smtp_return_error_details)
1971 if (!*user_msgptr && *log_msgptr)
1972 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1973 if (rc == DEFER) f.acl_temp_details = TRUE;
1978 /* Handle a sender address. The default is to verify *the* sender address, but
1979 optionally a different address can be given, for special requirements. If the
1980 address is empty, we are dealing with a bounce message that has no sender, so
1981 we cannot do any checking. If the real sender address gets rewritten during
1982 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1983 during message reception.
1985 A list of verified "sender" addresses is kept to try to avoid doing to much
1986 work repetitively when there are multiple recipients in a message and they all
1987 require sender verification. However, when callouts are involved, it gets too
1988 complicated because different recipients may require different callout options.
1989 Therefore, we always do a full sender verify when any kind of callout is
1990 specified. Caching elsewhere, for instance in the DNS resolver and in the
1991 callout handling, should ensure that this is not terribly inefficient. */
1993 else if (verify_sender_address)
1995 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1997 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1998 "sender verify callout";
2002 sender_vaddr = verify_checked_sender(verify_sender_address);
2003 if ( sender_vaddr /* Previously checked */
2004 && callout <= 0) /* No callout needed this time */
2006 /* If the "routed" flag is set, it means that routing worked before, so
2007 this check can give OK (the saved return code value, if set, belongs to a
2008 callout that was done previously). If the "routed" flag is not set, routing
2009 must have failed, so we use the saved return code. */
2011 if (testflag(sender_vaddr, af_verify_routed))
2015 rc = sender_vaddr->special_action;
2016 *basic_errno = sender_vaddr->basic_errno;
2018 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
2021 /* Do a new verification, and cache the result. The cache is used to avoid
2022 verifying the sender multiple times for multiple RCPTs when callouts are not
2023 specified (see comments above).
2025 The cache is also used on failure to give details in response to the first
2026 RCPT that gets bounced for this reason. However, this can be suppressed by
2027 the no_details option, which sets the flag that says "this detail has already
2028 been sent". The cache normally contains just one address, but there may be
2029 more in esoteric circumstances. */
2034 uschar *save_address_data = deliver_address_data;
2036 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
2038 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
2040 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
2041 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
2044 if (no_details) setflag(sender_vaddr, af_sverify_told);
2045 if (verify_sender_address[0] != 0)
2047 /* If this is the real sender address, save the unrewritten version
2048 for use later in receive. Otherwise, set a flag so that rewriting the
2049 sender in verify_address() does not update sender_address. */
2051 if (verify_sender_address == sender_address)
2052 sender_address_unrewritten = sender_address;
2054 verify_options |= vopt_fake_sender;
2056 if (success_on_redirect)
2057 verify_options |= vopt_success_on_redirect;
2059 /* The recipient, qualify, and expn options are never set in
2062 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2063 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2065 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2068 *basic_errno = sender_vaddr->basic_errno;
2071 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2072 debug_printf_indent("sender %s verified ok as %s\n",
2073 verify_sender_address, sender_vaddr->address);
2075 debug_printf_indent("sender %s verified ok\n",
2076 verify_sender_address);
2079 rc = OK; /* Null sender */
2081 /* Cache the result code */
2083 if (routed) setflag(sender_vaddr, af_verify_routed);
2084 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2085 sender_vaddr->special_action = rc;
2086 sender_vaddr->next = sender_verified_list;
2087 sender_verified_list = sender_vaddr;
2089 /* Restore the recipient address data, which might have been clobbered by
2090 the sender verification. */
2092 deliver_address_data = save_address_data;
2095 /* Put the sender address_data value into $sender_address_data */
2097 sender_address_data = sender_vaddr->prop.address_data;
2100 /* A recipient address just gets a straightforward verify; again we must handle
2101 the DEFER overrides. */
2107 if (success_on_redirect)
2108 verify_options |= vopt_success_on_redirect;
2110 /* We must use a copy of the address for verification, because it might
2114 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2115 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2116 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2118 *basic_errno = addr2.basic_errno;
2119 *log_msgptr = addr2.message;
2120 *user_msgptr = addr2.user_message ? addr2.user_message : addr2.message;
2122 /* Allow details for temporary error if the address is so flagged. */
2123 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2125 /* Make $address_data visible */
2126 deliver_address_data = addr2.prop.address_data;
2129 /* We have a result from the relevant test. Handle defer overrides first. */
2133 || callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER
2136 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2137 defer_ok? "defer_ok" : "callout_defer_ok");
2141 /* If we've failed a sender, set up a recipient message, and point
2142 sender_verified_failed to the address item that actually failed. */
2144 if (rc != OK && verify_sender_address)
2147 *log_msgptr = *user_msgptr = US"Sender verify failed";
2148 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2149 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2152 *log_msgptr = US"Could not complete sender verify callout";
2153 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2157 sender_verified_failed = sender_vaddr;
2160 /* Verifying an address messes up the values of $domain and $local_part,
2161 so reset them before returning if this is a RCPT ACL. */
2165 deliver_domain = addr->domain;
2166 deliver_localpart = addr->local_part;
2170 /* Syntax errors in the verify argument come here. */
2173 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2174 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2175 "or \"reverse_host_lookup\" at start of ACL condition "
2176 "\"verify %s\"", arg);
2183 /*************************************************
2184 * Check argument for control= modifier *
2185 *************************************************/
2187 /* Called from acl_check_condition() below.
2188 To handle the case "queue_only" we accept an _ in the
2189 initial / option-switch position.
2192 arg the argument string for control=
2193 pptr set to point to the terminating character
2194 where which ACL we are in
2195 log_msgptr for error messages
2197 Returns: CONTROL_xxx value
2201 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2207 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2208 || ( (c = arg[len = Ustrlen((d = controls_list+idx)->name)]) != 0
2209 && (!d->has_option || c != '/' && c != '_')
2212 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2213 return CONTROL_ERROR;
2223 /*************************************************
2224 * Return a ratelimit error *
2225 *************************************************/
2227 /* Called from acl_ratelimit() below
2230 log_msgptr for error messages
2231 format format string
2232 ... supplementary arguments
2238 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2242 string_cat(NULL, US"error in arguments to \"ratelimit\" condition: ");
2244 va_start(ap, format);
2245 g = string_vformat(g, SVFMT_EXTEND|SVFMT_REBUFFER, format, ap);
2248 gstring_release_unused(g);
2249 *log_msgptr = string_from_gstring(g);
2256 /*************************************************
2257 * Handle rate limiting *
2258 *************************************************/
2260 /* Called by acl_check_condition() below to calculate the result
2261 of the ACL ratelimit condition.
2263 Note that the return value might be slightly unexpected: if the
2264 sender's rate is above the limit then the result is OK. This is
2265 similar to the dnslists condition, and is so that you can write
2266 ACL clauses like: defer ratelimit = 15 / 1h
2269 arg the option string for ratelimit=
2270 where ACL_WHERE_xxxx indicating which ACL this is
2271 log_msgptr for error messages
2273 Returns: OK - Sender's rate is above limit
2274 FAIL - Sender's rate is below limit
2275 DEFER - Problem opening ratelimit database
2276 ERROR - Syntax error in options.
2280 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2282 double limit, period, count;
2285 uschar *unique = NULL;
2287 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2288 BOOL noupdate = FALSE, badacl = FALSE;
2289 int mode = RATE_PER_WHAT;
2291 tree_node **anchor, *t;
2292 open_db dbblock, *dbm;
2294 dbdata_ratelimit *dbd;
2295 dbdata_ratelimit_unique *dbdb;
2298 /* Parse the first two options and record their values in expansion
2299 variables. These variables allow the configuration to have informative
2300 error messages based on rate limits obtained from a table lookup. */
2302 /* First is the maximum number of messages per period / maximum burst
2303 size, which must be greater than or equal to zero. Zero is useful for
2304 rate measurement as opposed to rate limiting. */
2306 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2307 return ratelimit_error(log_msgptr, "sender rate limit not set");
2309 limit = Ustrtod(sender_rate_limit, &ss);
2310 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2311 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2312 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2314 if (limit < 0.0 || *ss != '\0')
2315 return ratelimit_error(log_msgptr,
2316 "\"%s\" is not a positive number", sender_rate_limit);
2318 /* Second is the rate measurement period / exponential smoothing time
2319 constant. This must be strictly greater than zero, because zero leads to
2320 run-time division errors. */
2322 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2323 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2325 return ratelimit_error(log_msgptr,
2326 "\"%s\" is not a time value", sender_rate_period);
2328 /* By default we are counting one of something, but the per_rcpt,
2329 per_byte, and count options can change this. */
2333 /* Parse the other options. */
2335 while ((ss = string_nextinlist(&arg, &sep, NULL, 0)))
2337 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2338 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2339 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2340 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2341 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2342 else if (strcmpic(ss, US"per_conn") == 0)
2344 RATE_SET(mode, PER_CONN);
2345 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2348 else if (strcmpic(ss, US"per_mail") == 0)
2350 RATE_SET(mode, PER_MAIL);
2351 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2353 else if (strcmpic(ss, US"per_rcpt") == 0)
2355 /* If we are running in the RCPT ACL, then we'll count the recipients
2356 one by one, but if we are running when we have accumulated the whole
2357 list then we'll add them all in one batch. */
2358 if (where == ACL_WHERE_RCPT)
2359 RATE_SET(mode, PER_RCPT);
2360 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2361 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2362 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2363 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2365 else if (strcmpic(ss, US"per_byte") == 0)
2367 /* If we have not yet received the message data and there was no SIZE
2368 declaration on the MAIL command, then it's safe to just use a value of
2369 zero and let the recorded rate decay as if nothing happened. */
2370 RATE_SET(mode, PER_MAIL);
2371 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2372 else count = message_size < 0 ? 0.0 : (double)message_size;
2374 else if (strcmpic(ss, US"per_addr") == 0)
2376 RATE_SET(mode, PER_RCPT);
2377 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2378 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2380 else if (strncmpic(ss, US"count=", 6) == 0)
2383 count = Ustrtod(ss+6, &e);
2384 if (count < 0.0 || *e != '\0')
2385 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2387 else if (strncmpic(ss, US"unique=", 7) == 0)
2388 unique = string_copy(ss + 7);
2390 key = string_copy(ss);
2392 key = string_sprintf("%s/%s", key, ss);
2395 /* Sanity check. When the badacl flag is set the update mode must either
2396 be readonly (which is the default if it is omitted) or, for backwards
2397 compatibility, a combination of noupdate and strict or leaky. */
2399 if (mode == RATE_PER_CLASH)
2400 return ratelimit_error(log_msgptr, "conflicting per_* options");
2401 if (leaky + strict + readonly > 1)
2402 return ratelimit_error(log_msgptr, "conflicting update modes");
2403 if (badacl && (leaky || strict) && !noupdate)
2404 return ratelimit_error(log_msgptr,
2405 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2406 ratelimit_option_string[mode], acl_wherenames[where]);
2408 /* Set the default values of any unset options. In readonly mode we
2409 perform the rate computation without any increment so that its value
2410 decays to eventually allow over-limit senders through. */
2412 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2413 if (badacl) readonly = TRUE;
2414 if (readonly) count = 0.0;
2415 if (!strict && !readonly) leaky = TRUE;
2416 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2418 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2419 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2420 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2421 are added to the key because they alter the meaning of the stored data. */
2424 key = !sender_host_address ? US"" : sender_host_address;
2426 key = string_sprintf("%s/%s/%s%s",
2428 ratelimit_option_string[mode],
2429 unique == NULL ? "" : "unique/",
2433 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2435 /* See if we have already computed the rate by looking in the relevant tree.
2436 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2437 pool so that they survive across resets. In readonly mode we only remember the
2438 result for the rest of this command in case a later command changes it. After
2439 this bit of logic the code is independent of the per_* mode. */
2441 old_pool = store_pool;
2444 anchor = &ratelimiters_cmd;
2448 anchor = &ratelimiters_conn;
2449 store_pool = POOL_PERM;
2453 case RATE_PER_ALLRCPTS:
2454 anchor = &ratelimiters_mail;
2459 anchor = &ratelimiters_cmd;
2462 anchor = NULL; /* silence an "unused" complaint */
2463 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2464 "internal ACL error: unknown ratelimit mode %d", mode);
2468 if ((t = tree_search(*anchor, key)))
2471 /* The following few lines duplicate some of the code below. */
2472 rc = (dbd->rate < limit)? FAIL : OK;
2473 store_pool = old_pool;
2474 sender_rate = string_sprintf("%.1f", dbd->rate);
2476 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2480 /* We aren't using a pre-computed rate, so get a previously recorded rate
2481 from the database, which will be updated and written back if required. */
2483 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE, TRUE)))
2485 store_pool = old_pool;
2487 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2488 *log_msgptr = US"ratelimit database not available";
2491 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2494 gettimeofday(&tv, NULL);
2498 /* Locate the basic ratelimit block inside the DB data. */
2499 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2502 /* Forget the old Bloom filter if it is too old, so that we count each
2503 repeating event once per period. We don't simply clear and re-use the old
2504 filter because we want its size to change if the limit changes. Note that
2505 we keep the dbd pointer for copying the rate into the new data block. */
2507 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2509 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2515 if(unique && dbdb_size < sizeof(*dbdb))
2517 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2522 /* Allocate a new data block if the database lookup failed
2523 or the Bloom filter passed its age limit. */
2529 /* No Bloom filter. This basic ratelimit block is initialized below. */
2530 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2531 dbdb_size = sizeof(*dbd);
2532 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2537 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2539 /* See the long comment below for an explanation of the magic number 2.
2540 The filter has a minimum size in case the rate limit is very small;
2541 this is determined by the definition of dbdata_ratelimit_unique. */
2543 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2544 if (extra < 0) extra = 0;
2545 dbdb_size = sizeof(*dbdb) + extra;
2546 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2547 dbdb->bloom_epoch = tv.tv_sec;
2548 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2549 memset(dbdb->bloom, 0, dbdb->bloom_size);
2551 /* Preserve any basic ratelimit data (which is our longer-term memory)
2552 by copying it from the discarded block. */
2562 /* If we are counting unique events, find out if this event is new or not.
2563 If the client repeats the event during the current period then it should be
2564 counted. We skip this code in readonly mode for efficiency, because any
2565 changes to the filter will be discarded and because count is already set to
2568 if (unique && !readonly)
2570 /* We identify unique events using a Bloom filter. (You can find my
2571 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2572 With the per_addr option, an "event" is a recipient address, though the
2573 user can use the unique option to define their own events. We only count
2574 an event if we have not seen it before.
2576 We size the filter according to the rate limit, which (in leaky mode)
2577 is the limit on the population of the filter. We allow 16 bits of space
2578 per entry (see the construction code above) and we set (up to) 8 of them
2579 when inserting an element (see the loop below). The probability of a false
2580 positive (an event we have not seen before but which we fail to count) is
2584 allzero = exp(-numhash * pop / size)
2585 = exp(-0.5 * pop / limit)
2586 fpr = pow(1 - allzero, numhash)
2588 For senders at the limit the fpr is 0.06% or 1 in 1700
2589 and for senders at half the limit it is 0.0006% or 1 in 170000
2591 In strict mode the Bloom filter can fill up beyond the normal limit, in
2592 which case the false positive rate will rise. This means that the
2593 measured rate for very fast senders can bogusly drop off after a while.
2595 At twice the limit, the fpr is 2.5% or 1 in 40
2596 At four times the limit, it is 31% or 1 in 3.2
2598 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2599 decay below the limit, and if this is more than one then the Bloom filter
2600 will be discarded before the decay gets that far. The false positive rate
2601 at this threshold is 9.3% or 1 in 10.7. */
2604 unsigned n, hash, hinc;
2608 /* Instead of using eight independent hash values, we combine two values
2609 using the formula h1 + n * h2. This does not harm the Bloom filter's
2610 performance, and means the amount of hash we need is independent of the
2611 number of bits we set in the filter. */
2613 md5_start(&md5info);
2614 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2615 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2616 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2618 /* Scan the bits corresponding to this event. A zero bit means we have
2619 not seen it before. Ensure all bits are set to record this event. */
2621 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2624 for (n = 0; n < 8; n++, hash += hinc)
2626 int bit = 1 << (hash % 8);
2627 int byte = (hash / 8) % dbdb->bloom_size;
2628 if ((dbdb->bloom[byte] & bit) == 0)
2630 dbdb->bloom[byte] |= bit;
2635 /* If this event has occurred before, do not count it. */
2639 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2643 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2646 /* If there was no previous ratelimit data block for this key, initialize
2647 the new one, otherwise update the block from the database. The initial rate
2648 is what would be computed by the code below for an infinite interval. */
2652 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2654 dbd->time_stamp = tv.tv_sec;
2655 dbd->time_usec = tv.tv_usec;
2660 /* The smoothed rate is computed using an exponentially weighted moving
2661 average adjusted for variable sampling intervals. The standard EWMA for
2662 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2663 where f() is the measured value and f'() is the smoothed value.
2665 Old data decays out of the smoothed value exponentially, such that data n
2666 samples old is multiplied by a^n. The exponential decay time constant p
2667 is defined such that data p samples old is multiplied by 1/e, which means
2668 that a = exp(-1/p). We can maintain the same time constant for a variable
2669 sampling interval i by using a = exp(-i/p).
2671 The rate we are measuring is messages per period, suitable for directly
2672 comparing with the limit. The average rate between now and the previous
2673 message is period / interval, which we feed into the EWMA as the sample.
2675 It turns out that the number of messages required for the smoothed rate
2676 to reach the limit when they are sent in a burst is equal to the limit.
2677 This can be seen by analysing the value of the smoothed rate after N
2678 messages sent at even intervals. Let k = (1 - a) * p/i
2680 rate_1 = (1 - a) * p/i + a * rate_0
2682 rate_2 = k + a * rate_1
2683 = k + a * k + a^2 * rate_0
2684 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2685 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2686 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2687 = rate_0 * a^N + p/i * (1 - a^N)
2689 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2691 rate_N = p/i + (rate_0 - p/i) * a^N
2692 a^N = (rate_N - p/i) / (rate_0 - p/i)
2693 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2694 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2696 Numerical analysis of the above equation, setting the computed rate to
2697 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2698 rates, p/i, the number of messages N = limit. So limit serves as both the
2699 maximum rate measured in messages per period, and the maximum number of
2700 messages that can be sent in a fast burst. */
2702 double this_time = (double)tv.tv_sec
2703 + (double)tv.tv_usec / 1000000.0;
2704 double prev_time = (double)dbd->time_stamp
2705 + (double)dbd->time_usec / 1000000.0;
2707 /* We must avoid division by zero, and deal gracefully with the clock going
2708 backwards. If we blunder ahead when time is in reverse then the computed
2709 rate will be bogus. To be safe we clamp interval to a very small number. */
2711 double interval = this_time - prev_time <= 0.0 ? 1e-9
2712 : this_time - prev_time;
2714 double i_over_p = interval / period;
2715 double a = exp(-i_over_p);
2717 /* Combine the instantaneous rate (period / interval) with the previous rate
2718 using the smoothing factor a. In order to measure sized events, multiply the
2719 instantaneous rate by the count of bytes or recipients etc. */
2721 dbd->time_stamp = tv.tv_sec;
2722 dbd->time_usec = tv.tv_usec;
2723 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2725 /* When events are very widely spaced the computed rate tends towards zero.
2726 Although this is accurate it turns out not to be useful for our purposes,
2727 especially when the first event after a long silence is the start of a spam
2728 run. A more useful model is that the rate for an isolated event should be the
2729 size of the event per the period size, ignoring the lack of events outside
2730 the current period and regardless of where the event falls in the period. So,
2731 if the interval was so long that the calculated rate is unhelpfully small, we
2732 re-initialize the rate. In the absence of higher-rate bursts, the condition
2733 below is true if the interval is greater than the period. */
2735 if (dbd->rate < count) dbd->rate = count;
2738 /* Clients sending at the limit are considered to be over the limit.
2739 This matters for edge cases such as a limit of zero, when the client
2740 should be completely blocked. */
2742 rc = dbd->rate < limit ? FAIL : OK;
2744 /* Update the state if the rate is low or if we are being strict. If we
2745 are in leaky mode and the sender's rate is too high, we do not update
2746 the recorded rate in order to avoid an over-aggressive sender's retry
2747 rate preventing them from getting any email through. If readonly is set,
2748 neither leaky nor strict are set, so we do not do any updates. */
2750 if ((rc == FAIL && leaky) || strict)
2752 dbfn_write(dbm, key, dbdb, dbdb_size);
2753 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2757 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2758 readonly? "readonly mode" : "over the limit, but leaky");
2763 /* Store the result in the tree for future reference. Take the taint status
2764 from the key for consistency even though it's unlikely we'll ever expand this. */
2766 t = store_get(sizeof(tree_node) + Ustrlen(key), is_tainted(key));
2768 Ustrcpy(t->name, key);
2769 (void)tree_insertnode(anchor, t);
2771 /* We create the formatted version of the sender's rate very late in
2772 order to ensure that it is done using the correct storage pool. */
2774 store_pool = old_pool;
2775 sender_rate = string_sprintf("%.1f", dbd->rate);
2778 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2785 /*************************************************
2786 * The udpsend ACL modifier *
2787 *************************************************/
2789 /* Called by acl_check_condition() below.
2792 arg the option string for udpsend=
2793 log_msgptr for error messages
2795 Returns: OK - Completed.
2796 DEFER - Problem with DNS lookup.
2797 ERROR - Syntax error in options.
2801 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2813 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2814 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2818 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2823 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2828 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2831 portnum = Ustrtol(portstr, &portend, 10);
2832 if (*portend != '\0')
2834 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2838 /* Make a single-item host list. */
2839 h = store_get(sizeof(host_item), FALSE);
2840 memset(h, 0, sizeof(host_item));
2845 if (string_is_ip_address(hostname, NULL))
2846 h->address = hostname, r = HOST_FOUND;
2848 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2849 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2851 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2856 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2858 /*XXX this could better use sendto */
2859 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2860 1, NULL, &errstr, NULL);
2861 if (r < 0) goto defer;
2863 r = send(s, arg, len, 0);
2866 errstr = US strerror(errno);
2874 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2879 debug_printf_indent("udpsend %d bytes\n", r);
2884 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2890 /*************************************************
2891 * Handle conditions/modifiers on an ACL item *
2892 *************************************************/
2894 /* Called from acl_check() below.
2898 cb ACL condition block - if NULL, result is OK
2899 where where called from
2900 addr the address being checked for RCPT, or NULL
2901 level the nesting level
2902 epp pointer to pass back TRUE if "endpass" encountered
2903 (applies only to "accept" and "discard")
2904 user_msgptr user message pointer
2905 log_msgptr log message pointer
2906 basic_errno pointer to where to put verify error
2908 Returns: OK - all conditions are met
2909 DISCARD - an "acl" condition returned DISCARD - only allowed
2910 for "accept" or "discard" verbs
2911 FAIL - at least one condition fails
2912 FAIL_DROP - an "acl" condition returned FAIL_DROP
2913 DEFER - can't tell at the moment (typically, lookup defer,
2914 but can be temporary callout problem)
2915 ERROR - ERROR from nested ACL or expansion failure or other
2920 acl_check_condition(int verb, acl_condition_block *cb, int where,
2921 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2922 uschar **log_msgptr, int *basic_errno)
2924 uschar *user_message = NULL;
2925 uschar *log_message = NULL;
2927 #ifdef WITH_CONTENT_SCAN
2931 for (; cb; cb = cb->next)
2936 /* The message and log_message items set up messages to be used in
2937 case of rejection. They are expanded later. */
2939 if (cb->type == ACLC_MESSAGE)
2941 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2942 user_message = cb->arg;
2946 if (cb->type == ACLC_LOG_MESSAGE)
2948 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2949 log_message = cb->arg;
2953 /* The endpass "condition" just sets a flag to show it occurred. This is
2954 checked at compile time to be on an "accept" or "discard" item. */
2956 if (cb->type == ACLC_ENDPASS)
2962 /* For other conditions and modifiers, the argument is expanded now for some
2963 of them, but not for all, because expansion happens down in some lower level
2964 checking functions in some cases. */
2966 if (!conditions[cb->type].expand_at_top)
2968 else if (!(arg = expand_string(cb->arg)))
2970 if (f.expand_string_forcedfail) continue;
2971 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2972 cb->arg, expand_string_message);
2973 return f.search_find_defer ? DEFER : ERROR;
2976 /* Show condition, and expanded condition if it's different */
2981 debug_printf_indent("check %s%s %n",
2982 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2983 conditions[cb->type].name, &lhswidth);
2985 if (cb->type == ACLC_SET)
2987 #ifndef DISABLE_DKIM
2988 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2989 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2991 debug_printf("%s ", cb->u.varname);
2997 debug_printf("acl_%s ", cb->u.varname);
2998 lhswidth += 5 + Ustrlen(cb->u.varname);
3002 debug_printf("= %s\n", cb->arg);
3005 debug_printf("%.*s= %s\n", lhswidth,
3009 /* Check that this condition makes sense at this time */
3011 if ((conditions[cb->type].forbids & (1 << where)) != 0)
3013 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
3014 conditions[cb->type].is_modifier ? "use" : "test",
3015 conditions[cb->type].name, acl_wherenames[where]);
3019 /* Run the appropriate test for each condition, or take the appropriate
3020 action for the remaining modifiers. */
3024 case ACLC_ADD_HEADER:
3028 /* A nested ACL that returns "discard" makes sense only for an "accept" or
3032 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
3033 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
3035 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
3036 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
3042 case ACLC_AUTHENTICATED:
3043 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
3044 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
3047 #ifdef EXPERIMENTAL_BRIGHTMAIL
3048 case ACLC_BMI_OPTIN:
3050 int old_pool = store_pool;
3051 store_pool = POOL_PERM;
3052 bmi_current_optin = string_copy(arg);
3053 store_pool = old_pool;
3058 case ACLC_CONDITION:
3059 /* The true/false parsing here should be kept in sync with that used in
3060 expand.c when dealing with ECOND_BOOL so that we don't have too many
3061 different definitions of what can be a boolean. */
3063 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
3064 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
3065 rc = (Uatoi(arg) == 0)? FAIL : OK;
3067 rc = (strcmpic(arg, US"no") == 0 ||
3068 strcmpic(arg, US"false") == 0)? FAIL :
3069 (strcmpic(arg, US"yes") == 0 ||
3070 strcmpic(arg, US"true") == 0)? OK : DEFER;
3072 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3075 case ACLC_CONTINUE: /* Always succeeds */
3080 const uschar *p = NULL;
3081 control_type = decode_control(arg, &p, where, log_msgptr);
3083 /* Check if this control makes sense at this time */
3085 if (controls_list[control_type].forbids & (1 << where))
3087 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3088 controls_list[control_type].name, acl_wherenames[where]);
3092 switch(control_type)
3094 case CONTROL_AUTH_UNADVERTISED:
3095 f.allow_auth_unadvertised = TRUE;
3098 #ifdef EXPERIMENTAL_BRIGHTMAIL
3099 case CONTROL_BMI_RUN:
3104 #ifndef DISABLE_DKIM
3105 case CONTROL_DKIM_VERIFY:
3106 f.dkim_disable_verify = TRUE;
3107 # ifdef SUPPORT_DMARC
3108 /* Since DKIM was blocked, skip DMARC too */
3109 f.dmarc_disable_verify = TRUE;
3110 f.dmarc_enable_forensic = FALSE;
3115 #ifdef SUPPORT_DMARC
3116 case CONTROL_DMARC_VERIFY:
3117 f.dmarc_disable_verify = TRUE;
3120 case CONTROL_DMARC_FORENSIC:
3121 f.dmarc_enable_forensic = TRUE;
3128 int fd, af, level, optname, value;
3129 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3130 a socket; we can accept that, we'll just debug-log failures anyway. */
3131 fd = fileno(smtp_in);
3132 if ((af = ip_get_address_family(fd)) < 0)
3135 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3139 if (dscp_lookup(p+1, af, &level, &optname, &value))
3140 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3142 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3143 p+1, strerror(errno));
3147 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3151 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3157 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3165 case CONTROL_CASEFUL_LOCAL_PART:
3166 deliver_localpart = addr->cc_local_part;
3169 case CONTROL_CASELOWER_LOCAL_PART:
3170 deliver_localpart = addr->lc_local_part;
3173 case CONTROL_ENFORCE_SYNC:
3174 smtp_enforce_sync = TRUE;
3177 case CONTROL_NO_ENFORCE_SYNC:
3178 smtp_enforce_sync = FALSE;
3181 #ifdef WITH_CONTENT_SCAN
3182 case CONTROL_NO_MBOX_UNSPOOL:
3183 f.no_mbox_unspool = TRUE;
3187 case CONTROL_NO_MULTILINE:
3188 f.no_multiline_responses = TRUE;
3191 case CONTROL_NO_PIPELINING:
3192 f.pipelining_enable = FALSE;
3195 case CONTROL_NO_DELAY_FLUSH:
3196 f.disable_delay_flush = TRUE;
3199 case CONTROL_NO_CALLOUT_FLUSH:
3200 f.disable_callout_flush = TRUE;
3203 case CONTROL_FAKEREJECT:
3204 cancel_cutthrough_connection(TRUE, US"fakereject");
3205 case CONTROL_FAKEDEFER:
3206 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3209 const uschar *pp = p + 1;
3211 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3214 else /* Explicitly reset to default string */
3215 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).";
3218 case CONTROL_FREEZE:
3219 f.deliver_freeze = TRUE;
3220 deliver_frozen_at = time(NULL);
3221 freeze_tell = freeze_tell_config; /* Reset to configured value */
3222 if (Ustrncmp(p, "/no_tell", 8) == 0)
3229 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3232 cancel_cutthrough_connection(TRUE, US"item frozen");
3236 f.queue_only_policy = TRUE;
3237 if (Ustrcmp(p, "_only") == 0)
3239 else while (*p == '/')
3240 if (Ustrncmp(p, "/only", 5) == 0)
3241 { p += 5; f.queue_smtp = FALSE; }
3242 else if (Ustrncmp(p, "/first_pass_route", 17) == 0)
3243 { p += 17; f.queue_smtp = TRUE; }
3246 cancel_cutthrough_connection(TRUE, US"queueing forced");
3249 case CONTROL_SUBMISSION:
3250 originator_name = US"";
3251 f.submission_mode = TRUE;
3254 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3257 f.active_local_sender_retain = TRUE;
3258 f.active_local_from_check = FALSE;
3260 else if (Ustrncmp(p, "/domain=", 8) == 0)
3262 const uschar *pp = p + 8;
3263 while (*pp && *pp != '/') pp++;
3264 submission_domain = string_copyn(p+8, pp-p-8);
3267 /* The name= option must be last, because it swallows the rest of
3269 else if (Ustrncmp(p, "/name=", 6) == 0)
3271 const uschar *pp = p + 6;
3273 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3274 big_buffer, big_buffer_size));
3281 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3288 uschar * debug_tag = NULL;
3289 uschar * debug_opts = NULL;
3294 const uschar * pp = p+1;
3295 if (Ustrncmp(pp, "tag=", 4) == 0)
3297 for (pp += 4; *pp && *pp != '/';) pp++;
3298 debug_tag = string_copyn(p+5, pp-p-5);
3300 else if (Ustrncmp(pp, "opts=", 5) == 0)
3302 for (pp += 5; *pp && *pp != '/';) pp++;
3303 debug_opts = string_copyn(p+6, pp-p-6);
3305 else if (Ustrncmp(pp, "kill", 4) == 0)
3307 for (pp += 4; *pp && *pp != '/';) pp++;
3311 while (*pp && *pp != '/') pp++;
3316 debug_logging_stop();
3318 debug_logging_activate(debug_tag, debug_opts);
3322 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3323 f.suppress_local_fixups = TRUE;
3326 case CONTROL_CUTTHROUGH_DELIVERY:
3328 uschar * ignored = NULL;
3329 #ifndef DISABLE_PRDR
3334 /* Too hard to think about for now. We might in future cutthrough
3335 the case where both sides handle prdr and this-node prdr acl
3337 ignored = US"PRDR active";
3340 if (f.deliver_freeze)
3341 ignored = US"frozen";
3342 else if (f.queue_only_policy)
3343 ignored = US"queue-only";
3344 else if (fake_response == FAIL)
3345 ignored = US"fakereject";
3348 if (rcpt_count == 1)
3350 cutthrough.delivery = TRUE; /* control accepted */
3353 const uschar * pp = p+1;
3354 if (Ustrncmp(pp, "defer=", 6) == 0)
3357 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3358 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3361 while (*pp && *pp != '/') pp++;
3366 ignored = US"nonfirst rcpt";
3369 DEBUG(D_acl) if (ignored)
3370 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3375 case CONTROL_UTF8_DOWNCONVERT:
3380 message_utf8_downconvert = 1;
3381 addr->prop.utf8_downcvt = TRUE;
3382 addr->prop.utf8_downcvt_maybe = FALSE;
3388 message_utf8_downconvert = 0;
3389 addr->prop.utf8_downcvt = FALSE;
3390 addr->prop.utf8_downcvt_maybe = FALSE;
3394 if (p[1] == '-' && p[2] == '1')
3396 message_utf8_downconvert = -1;
3397 addr->prop.utf8_downcvt = FALSE;
3398 addr->prop.utf8_downcvt_maybe = TRUE;
3402 *log_msgptr = US"bad option value for control=utf8_downconvert";
3406 message_utf8_downconvert = 1;
3407 addr->prop.utf8_downcvt = TRUE;
3408 addr->prop.utf8_downcvt_maybe = FALSE;
3418 #ifdef EXPERIMENTAL_DCC
3421 /* Separate the regular expression and any optional parameters. */
3422 const uschar * list = arg;
3423 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
3424 /* Run the dcc backend. */
3425 rc = dcc_process(&ss);
3426 /* Modify return code based upon the existence of options. */
3427 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
3428 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3429 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3434 #ifdef WITH_CONTENT_SCAN
3436 rc = mime_decode(&arg);
3442 int delay = readconf_readtime(arg, 0, FALSE);
3445 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3446 "modifier: \"%s\" is not a time value", arg);
3451 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3456 debug_printf_indent("delay skipped in -bh checking mode\n");
3459 /* NOTE 1: Remember that we may be
3460 dealing with stdin/stdout here, in addition to TCP/IP connections.
3461 Also, delays may be specified for non-SMTP input, where smtp_out and
3462 smtp_in will be NULL. Whatever is done must work in all cases.
3464 NOTE 2: The added feature of flushing the output before a delay must
3465 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3470 if (smtp_out && !f.disable_delay_flush)
3473 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3479 p.fd = fileno(smtp_out);
3480 p.events = POLLRDHUP;
3483 if (poll(&p, n, delay*1000) > 0)
3484 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3487 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3488 TCP/IP connection has gone away without reading from it. This means
3489 that we cannot shorten the delay below if the client goes away,
3490 because we cannot discover that the client has closed its end of the
3491 connection. (The connection is actually in a half-closed state,
3492 waiting for the server to close its end.) It would be nice to be able
3493 to detect this state, so that the Exim process is not held up
3494 unnecessarily. However, it seems that we can't. The poll() function
3495 does not do the right thing, and in any case it is not always
3498 while (delay > 0) delay = sleep(delay);
3505 #ifndef DISABLE_DKIM
3506 case ACLC_DKIM_SIGNER:
3507 if (dkim_cur_signer)
3508 rc = match_isinlist(dkim_cur_signer,
3509 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3514 case ACLC_DKIM_STATUS:
3515 rc = match_isinlist(dkim_verify_status,
3516 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3520 #ifdef SUPPORT_DMARC
3521 case ACLC_DMARC_STATUS:
3522 if (!f.dmarc_has_been_checked)
3524 f.dmarc_has_been_checked = TRUE;
3525 /* used long way of dmarc_exim_expand_query() in case we need more
3526 * view into the process in the future. */
3527 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3528 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3533 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3537 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3538 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3541 /* The value in tls_cipher is the full cipher name, for example,
3542 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3543 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3544 what may in practice come out of the SSL library - which at the time of
3545 writing is poorly documented. */
3547 case ACLC_ENCRYPTED:
3548 if (tls_in.cipher == NULL) rc = FAIL; else
3550 uschar *endcipher = NULL;
3551 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3552 if (!cipher) cipher = tls_in.cipher; else
3554 endcipher = Ustrchr(++cipher, ':');
3555 if (endcipher) *endcipher = 0;
3557 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3558 if (endcipher) *endcipher = ':';
3562 /* Use verify_check_this_host() instead of verify_check_host() so that
3563 we can pass over &host_data to catch any looked up data. Once it has been
3564 set, it retains its value so that it's still there if another ACL verb
3565 comes through here and uses the cache. However, we must put it into
3566 permanent store in case it is also expected to be used in a subsequent
3567 message in the same SMTP connection. */
3570 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3571 sender_host_address ? sender_host_address : US"", CUSS &host_data);
3572 if (rc == DEFER) *log_msgptr = search_error_message;
3573 if (host_data) host_data = string_copy_perm(host_data, TRUE);
3576 case ACLC_LOCAL_PARTS:
3577 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3578 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3579 CUSS &deliver_localpart_data);
3582 case ACLC_LOG_REJECT_TARGET:
3586 const uschar *s = arg;
3588 while ((ss = string_nextinlist(&s, &sep, NULL, 0)))
3590 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3591 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3592 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3595 logbits |= LOG_MAIN|LOG_REJECT;
3596 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3597 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3600 log_reject_target = logbits;
3607 const uschar *s = arg;
3613 if (Ustrncmp(s, "main", 4) == 0)
3614 { logbits |= LOG_MAIN; s += 4; }
3615 else if (Ustrncmp(s, "panic", 5) == 0)
3616 { logbits |= LOG_PANIC; s += 5; }
3617 else if (Ustrncmp(s, "reject", 6) == 0)
3618 { logbits |= LOG_REJECT; s += 6; }
3621 logbits = LOG_MAIN|LOG_PANIC;
3622 s = string_sprintf(":unknown log name in \"%s\" in "
3623 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3629 while (isspace(*s)) s++;
3631 if (logbits == 0) logbits = LOG_MAIN;
3632 log_write(0, logbits, "%s", string_printing(s));
3636 #ifdef WITH_CONTENT_SCAN
3637 case ACLC_MALWARE: /* Run the malware backend. */
3639 /* Separate the regular expression and any optional parameters. */
3640 const uschar * list = arg;
3641 uschar * ss = string_nextinlist(&list, &sep, NULL, 0);
3643 BOOL defer_ok = FALSE;
3646 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3647 if (strcmpic(opt, US"defer_ok") == 0)
3649 else if ( strncmpic(opt, US"tmo=", 4) == 0
3650 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3653 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3657 rc = malware(ss, timeout);
3658 if (rc == DEFER && defer_ok)
3659 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3663 case ACLC_MIME_REGEX:
3664 rc = mime_regex(&arg);
3669 if (is_tainted(arg))
3671 *log_msgptr = string_sprintf("Tainted name '%s' for queue not permitted",
3675 if (Ustrchr(arg, '/'))
3677 *log_msgptr = string_sprintf(
3678 "Directory separator not permitted in queue name: '%s'", arg);
3681 queue_name = string_copy_perm(arg, FALSE);
3684 case ACLC_RATELIMIT:
3685 rc = acl_ratelimit(arg, where, log_msgptr);
3688 case ACLC_RECIPIENTS:
3689 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3690 CUSS &recipient_data);
3693 #ifdef WITH_CONTENT_SCAN
3699 case ACLC_REMOVE_HEADER:
3700 setup_remove_header(arg);
3703 case ACLC_SENDER_DOMAINS:
3706 sdomain = Ustrrchr(sender_address, '@');
3707 sdomain = sdomain ? sdomain + 1 : US"";
3708 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3709 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3714 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3715 sender_address_cache, -1, 0, CUSS &sender_data);
3718 /* Connection variables must persist forever; message variables not */
3722 int old_pool = store_pool;
3723 if ( cb->u.varname[0] != 'm'
3724 #ifndef DISABLE_EVENT
3725 || event_name /* An event is being delivered */
3728 store_pool = POOL_PERM;
3729 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3730 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3731 dkim_verify_status = string_copy(arg);
3732 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3733 dkim_verify_reason = string_copy(arg);
3736 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3737 store_pool = old_pool;
3741 #ifdef WITH_CONTENT_SCAN
3744 /* Separate the regular expression and any optional parameters. */
3745 const uschar * list = arg;
3746 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
3748 rc = spam(CUSS &ss);
3749 /* Modify return code based upon the existence of options. */
3750 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
3751 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3752 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3759 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3761 case ACLC_SPF_GUESS:
3762 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3767 rc = acl_udpsend(arg, log_msgptr);
3770 /* If the verb is WARN, discard any user message from verification, because
3771 such messages are SMTP responses, not header additions. The latter come
3772 only from explicit "message" modifiers. However, put the user message into
3773 $acl_verify_message so it can be used in subsequent conditions or modifiers
3774 (until something changes it). */
3777 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3779 acl_verify_message = *user_msgptr;
3780 if (verb == ACL_WARN) *user_msgptr = NULL;
3784 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3785 "condition %d", cb->type);
3789 /* If a condition was negated, invert OK/FAIL. */
3791 if (!conditions[cb->type].is_modifier && cb->u.negated)
3792 if (rc == OK) rc = FAIL;
3793 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3795 if (rc != OK) break; /* Conditions loop */
3799 /* If the result is the one for which "message" and/or "log_message" are used,
3800 handle the values of these modifiers. If there isn't a log message set, we make
3801 it the same as the user message.
3803 "message" is a user message that will be included in an SMTP response. Unless
3804 it is empty, it overrides any previously set user message.
3806 "log_message" is a non-user message, and it adds to any existing non-user
3807 message that is already set.
3809 Most verbs have but a single return for which the messages are relevant, but
3810 for "discard", it's useful to have the log message both when it succeeds and
3811 when it fails. For "accept", the message is used in the OK case if there is no
3812 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3815 if (*epp && rc == OK) user_message = NULL;
3817 if ((BIT(rc) & msgcond[verb]) != 0)
3820 uschar *old_user_msgptr = *user_msgptr;
3821 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3823 /* If the verb is "warn", messages generated by conditions (verification or
3824 nested ACLs) are always discarded. This also happens for acceptance verbs
3825 when they actually do accept. Only messages specified at this level are used.
3826 However, the value of an existing message is available in $acl_verify_message
3827 during expansions. */
3829 if (verb == ACL_WARN ||
3830 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3831 *log_msgptr = *user_msgptr = NULL;
3835 acl_verify_message = old_user_msgptr;
3836 expmessage = expand_string(user_message);
3839 if (!f.expand_string_forcedfail)
3840 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3841 user_message, expand_string_message);
3843 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3848 acl_verify_message = old_log_msgptr;
3849 expmessage = expand_string(log_message);
3852 if (!f.expand_string_forcedfail)
3853 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3854 log_message, expand_string_message);
3856 else if (expmessage[0] != 0)
3858 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3859 string_sprintf("%s: %s", expmessage, *log_msgptr);
3863 /* If no log message, default it to the user message */
3865 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3868 acl_verify_message = NULL;
3876 /*************************************************
3877 * Get line from a literal ACL *
3878 *************************************************/
3880 /* This function is passed to acl_read() in order to extract individual lines
3881 of a literal ACL, which we access via static pointers. We can destroy the
3882 contents because this is called only once (the compiled ACL is remembered).
3884 This code is intended to treat the data in the same way as lines in the main
3885 Exim configuration file. That is:
3887 . Leading spaces are ignored.
3889 . A \ at the end of a line is a continuation - trailing spaces after the \
3890 are permitted (this is because I don't believe in making invisible things
3891 significant). Leading spaces on the continued part of a line are ignored.
3893 . Physical lines starting (significantly) with # are totally ignored, and
3894 may appear within a sequence of backslash-continued lines.
3896 . Blank lines are ignored, but will end a sequence of continuations.
3899 Returns: a pointer to the next line
3903 static uschar *acl_text; /* Current pointer in the text */
3904 static uschar *acl_text_end; /* Points one past the terminating '0' */
3912 /* This loop handles leading blank lines and comments. */
3916 Uskip_whitespace(&acl_text); /* Leading spaces/empty lines */
3917 if (!*acl_text) return NULL; /* No more data */
3918 yield = acl_text; /* Potential data line */
3920 while (*acl_text && *acl_text != '\n') acl_text++;
3922 /* If we hit the end before a newline, we have the whole logical line. If
3923 it's a comment, there's no more data to be given. Otherwise, yield it. */
3925 if (!*acl_text) return *yield == '#' ? NULL : yield;
3927 /* After reaching a newline, end this loop if the physical line does not
3928 start with '#'. If it does, it's a comment, and the loop continues. */
3930 if (*yield != '#') break;
3933 /* This loop handles continuations. We know we have some real data, ending in
3934 newline. See if there is a continuation marker at the end (ignoring trailing
3935 white space). We know that *yield is not white space, so no need to test for
3936 cont > yield in the backwards scanning loop. */
3941 for (cont = acl_text - 1; isspace(*cont); cont--);
3943 /* If no continuation follows, we are done. Mark the end of the line and
3952 /* We have encountered a continuation. Skip over whitespace at the start of
3953 the next line, and indeed the whole of the next line or lines if they are
3958 while (*(++acl_text) == ' ' || *acl_text == '\t');
3959 if (*acl_text != '#') break;
3960 while (*(++acl_text) != 0 && *acl_text != '\n');
3963 /* We have the start of a continuation line. Move all the rest of the data
3964 to join onto the previous line, and then find its end. If the end is not a
3965 newline, we are done. Otherwise loop to look for another continuation. */
3967 memmove(cont, acl_text, acl_text_end - acl_text);
3968 acl_text_end -= acl_text - cont;
3970 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3971 if (*acl_text == 0) return yield;
3974 /* Control does not reach here */
3981 /*************************************************
3982 * Check access using an ACL *
3983 *************************************************/
3985 /* This function is called from address_check. It may recurse via
3986 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3987 passed as a string which is expanded. A forced failure implies no access check
3988 is required. If the result is a single word, it is taken as the name of an ACL
3989 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3990 text, complete with newlines, and parsed as such. In both cases, the ACL check
3991 is then run. This function uses an auxiliary function for acl_read() to call
3992 for reading individual lines of a literal ACL. This is acl_getline(), which
3993 appears immediately above.
3996 where where called from
3997 addr address item when called from RCPT; otherwise NULL
3998 s the input string; NULL is the same as an empty ACL => DENY
3999 user_msgptr where to put a user error (for SMTP response)
4000 log_msgptr where to put a logging message (not for SMTP response)
4002 Returns: OK access is granted
4003 DISCARD access is apparently granted...
4004 FAIL access is denied
4005 FAIL_DROP access is denied; drop the connection
4006 DEFER can't tell at the moment
4011 acl_check_internal(int where, address_item *addr, uschar *s,
4012 uschar **user_msgptr, uschar **log_msgptr)
4015 acl_block *acl = NULL;
4016 uschar *acl_name = US"inline ACL";
4019 /* Catch configuration loops */
4023 *log_msgptr = US"ACL nested too deep: possible loop";
4029 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
4033 /* At top level, we expand the incoming string. At lower levels, it has already
4034 been expanded as part of condition processing. */
4038 if (!(ss = expand_string(s)))
4040 if (f.expand_string_forcedfail) return OK;
4041 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
4042 expand_string_message);
4048 while (isspace(*ss)) ss++;
4050 /* If we can't find a named ACL, the default is to parse it as an inline one.
4051 (Unless it begins with a slash; non-existent files give rise to an error.) */
4055 /* Handle the case of a string that does not contain any spaces. Look for a
4056 named ACL among those read from the configuration, or a previously read file.
4057 It is possible that the pointer to the ACL is NULL if the configuration
4058 contains a name with no data. If not found, and the text begins with '/',
4059 read an ACL from a file, and save it so it can be re-used. */
4061 if (Ustrchr(ss, ' ') == NULL)
4063 tree_node * t = tree_search(acl_anchor, ss);
4066 if (!(acl = (acl_block *)(t->data.ptr)))
4068 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
4071 acl_name = string_sprintf("ACL \"%s\"", ss);
4072 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4075 else if (*ss == '/')
4077 struct stat statbuf;
4080 log_write(0, LOG_MAIN|LOG_PANIC,
4081 "attempt to open tainted ACL file name \"%s\"", ss);
4082 /* Avoid leaking info to an attacker */
4083 *log_msgptr = US"internal configuration error";
4086 if ((fd = Uopen(ss, O_RDONLY, 0)) < 0)
4088 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4092 if (fstat(fd, &statbuf) != 0)
4094 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4099 /* If the string being used as a filename is tainted, so is the file content */
4100 acl_text = store_get(statbuf.st_size + 1, is_tainted(ss));
4101 acl_text_end = acl_text + statbuf.st_size + 1;
4103 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4105 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4106 ss, strerror(errno));
4109 acl_text[statbuf.st_size] = 0;
4112 acl_name = string_sprintf("ACL \"%s\"", ss);
4113 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4117 /* Parse an ACL that is still in text form. If it came from a file, remember it
4118 in the ACL tree, having read it into the POOL_PERM store pool so that it
4119 persists between multiple messages. */
4123 int old_pool = store_pool;
4124 if (fd >= 0) store_pool = POOL_PERM;
4125 acl = acl_read(acl_getline, log_msgptr);
4126 store_pool = old_pool;
4127 if (!acl && *log_msgptr) return ERROR;
4130 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss), is_tainted(ss));
4131 Ustrcpy(t->name, ss);
4133 (void)tree_insertnode(&acl_anchor, t);
4137 /* Now we have an ACL to use. It's possible it may be NULL. */
4142 int basic_errno = 0;
4143 BOOL endpass_seen = FALSE;
4144 BOOL acl_quit_check = acl_level == 0
4145 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4147 *log_msgptr = *user_msgptr = NULL;
4148 f.acl_temp_details = FALSE;
4150 HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n",
4151 verbs[acl->verb], acl->srcfile, acl->srcline);
4153 /* Clear out any search error message from a previous check before testing
4156 search_error_message = NULL;
4157 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4158 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4160 /* Handle special returns: DEFER causes a return except on a WARN verb;
4161 ERROR always causes a return. */
4166 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n",
4167 verbs[acl->verb], acl_name);
4168 if (basic_errno != ERRNO_CALLOUTDEFER)
4170 if (search_error_message != NULL && *search_error_message != 0)
4171 *log_msgptr = search_error_message;
4172 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4175 f.acl_temp_details = TRUE;
4176 if (acl->verb != ACL_WARN) return DEFER;
4179 default: /* Paranoia */
4181 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n",
4182 verbs[acl->verb], acl_name);
4186 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4187 verbs[acl->verb], acl_name);
4191 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n",
4192 verbs[acl->verb], acl_name);
4195 /* DISCARD and DROP can happen only from a nested ACL condition, and
4196 DISCARD can happen only for an "accept" or "discard" verb. */
4199 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4200 verbs[acl->verb], acl_name);
4204 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4205 verbs[acl->verb], acl_name);
4209 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4210 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4211 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4216 if (cond == OK || cond == DISCARD)
4218 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4223 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4231 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4232 if (acl_quit_check) goto badquit;
4233 f.acl_temp_details = TRUE;
4241 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4242 if (acl_quit_check) goto badquit;
4248 if (cond == OK || cond == DISCARD)
4250 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4251 if (acl_quit_check) goto badquit;
4257 debug_printf_indent("discard: endpass encountered - denying access\n");
4265 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4266 if (acl_quit_check) goto badquit;
4274 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4275 if (acl_quit_check) goto badquit;
4282 acl_warn(where, *user_msgptr, *log_msgptr);
4283 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4284 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4285 "condition test deferred%s%s", host_and_ident(TRUE),
4286 (*log_msgptr == NULL)? US"" : US": ",
4287 (*log_msgptr == NULL)? US"" : *log_msgptr);
4288 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4292 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4297 /* Pass to the next ACL item */
4302 /* We have reached the end of the ACL. This is an implicit DENY. */
4304 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4308 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4309 "('%s' verb used incorrectly)", verbs[acl->verb]);
4316 /* Same args as acl_check_internal() above, but the string s is
4317 the name of an ACL followed optionally by up to 9 space-separated arguments.
4318 The name and args are separately expanded. Args go into $acl_arg globals. */
4320 acl_check_wargs(int where, address_item *addr, const uschar *s,
4321 uschar **user_msgptr, uschar **log_msgptr)
4324 uschar * tmp_arg[9]; /* must match acl_arg[] */
4325 uschar * sav_arg[9]; /* must match acl_arg[] */
4331 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4334 for (i = 0; i < 9; i++)
4336 while (*s && isspace(*s)) s++;
4338 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4345 sav_narg = acl_narg;
4347 for (i = 0; i < acl_narg; i++)
4349 sav_arg[i] = acl_arg[i];
4350 acl_arg[i] = tmp_arg[i];
4354 sav_arg[i] = acl_arg[i];
4355 acl_arg[i++] = NULL;
4359 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4362 acl_narg = sav_narg;
4363 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4367 if (f.expand_string_forcedfail) return ERROR;
4368 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4369 tmp, expand_string_message);
4370 return f.search_find_defer ? DEFER : ERROR;
4375 /*************************************************
4376 * Check access using an ACL *
4377 *************************************************/
4379 /* Alternate interface for ACL, used by expansions */
4381 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4384 address_item *addr = NULL;
4387 *user_msgptr = *log_msgptr = NULL;
4388 sender_verified_failed = NULL;
4389 ratelimiters_cmd = NULL;
4390 log_reject_target = LOG_MAIN|LOG_REJECT;
4392 if (where == ACL_WHERE_RCPT)
4394 adb = address_defaults;
4396 addr->address = expand_string(US"$local_part@$domain");
4397 addr->domain = deliver_domain;
4398 addr->local_part = deliver_localpart;
4399 addr->cc_local_part = deliver_localpart;
4400 addr->lc_local_part = deliver_localpart;
4404 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4411 /* This is the external interface for ACL checks. It sets up an address and the
4412 expansions for $domain and $local_part when called after RCPT, then calls
4413 acl_check_internal() to do the actual work.
4416 where ACL_WHERE_xxxx indicating where called from
4417 recipient RCPT address for RCPT check, else NULL
4418 s the input string; NULL is the same as an empty ACL => DENY
4419 user_msgptr where to put a user error (for SMTP response)
4420 log_msgptr where to put a logging message (not for SMTP response)
4422 Returns: OK access is granted by an ACCEPT verb
4423 DISCARD access is granted by a DISCARD verb
4424 FAIL access is denied
4425 FAIL_DROP access is denied; drop the connection
4426 DEFER can't tell at the moment
4429 int acl_where = ACL_WHERE_UNKNOWN;
4432 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4433 uschar **log_msgptr)
4437 address_item *addr = NULL;
4439 *user_msgptr = *log_msgptr = NULL;
4440 sender_verified_failed = NULL;
4441 ratelimiters_cmd = NULL;
4442 log_reject_target = LOG_MAIN|LOG_REJECT;
4444 #ifndef DISABLE_PRDR
4445 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4447 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4450 adb = address_defaults;
4452 addr->address = recipient;
4453 if (deliver_split_address(addr) == DEFER)
4455 *log_msgptr = US"defer in percent_hack_domains check";
4459 if ((addr->prop.utf8_msg = message_smtputf8))
4461 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4462 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4465 deliver_domain = addr->domain;
4466 deliver_localpart = addr->local_part;
4471 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4473 acl_where = ACL_WHERE_UNKNOWN;
4475 /* Cutthrough - if requested,
4476 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4477 and rcpt acl returned accept,
4478 and first recipient (cancel on any subsequents)
4479 open one now and run it up to RCPT acceptance.
4480 A failed verify should cancel cutthrough request,
4481 and will pass the fail to the originator.
4482 Initial implementation: dual-write to spool.
4483 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4485 Cease cutthrough copy on rxd final dot; do not send one.
4487 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4489 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4490 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4491 If temp-reject, close the conn (and keep the spooled copy).
4492 If conn-failure, no action (and keep the spooled copy).
4496 case ACL_WHERE_RCPT:
4497 #ifndef DISABLE_PRDR
4498 case ACL_WHERE_PRDR:
4501 if (f.host_checking_callout) /* -bhc mode */
4502 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4505 && cutthrough.delivery
4506 && rcpt_count > cutthrough.nrcpt
4509 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4510 if (cutthrough.defer_pass)
4512 uschar * s = addr->message;
4513 /* Horrid kludge to recover target's SMTP message */
4515 do --s; while (!isdigit(*s));
4516 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4517 f.acl_temp_details = TRUE;
4521 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4525 else HDEBUG(D_acl) if (cutthrough.delivery)
4526 if (rcpt_count <= cutthrough.nrcpt)
4527 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4529 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4532 case ACL_WHERE_PREDATA:
4534 cutthrough_predata();
4536 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4539 case ACL_WHERE_QUIT:
4540 case ACL_WHERE_NOTQUIT:
4541 /* Drop cutthrough conns, and drop heldopen verify conns if
4542 the previous was not DATA */
4544 uschar prev = smtp_connection_had[smtp_ch_index-2];
4545 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4547 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4555 deliver_domain = deliver_localpart = deliver_address_data =
4556 deliver_domain_data = sender_address_data = NULL;
4558 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4559 ACL, which is really in the middle of an SMTP command. */
4563 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4565 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4566 "ACL", acl_wherenames[where]);
4572 /* A DROP response is not permitted from MAILAUTH */
4574 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4576 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4577 "ACL", acl_wherenames[where]);
4581 /* Before giving a response, take a look at the length of any user message, and
4582 split it up into multiple lines if possible. */
4584 *user_msgptr = string_split_message(*user_msgptr);
4585 if (fake_response != OK)
4586 fake_response_text = string_split_message(fake_response_text);
4592 /*************************************************
4593 * Create ACL variable *
4594 *************************************************/
4596 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4597 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4600 name pointer to the variable's name, starting with c or m
4602 Returns the pointer to variable's tree node
4606 acl_var_create(uschar * name)
4608 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4609 if (!(node = tree_search(*root, name)))
4611 node = store_get(sizeof(tree_node) + Ustrlen(name), is_tainted(name));
4612 Ustrcpy(node->name, name);
4613 (void)tree_insertnode(root, node);
4615 node->data.ptr = NULL;
4621 /*************************************************
4622 * Write an ACL variable in spool format *
4623 *************************************************/
4625 /* This function is used as a callback for tree_walk when writing variables to
4626 the spool file. To retain spool file compatibility, what is written is -aclc or
4627 -aclm followed by the rest of the name and the data length, space separated,
4628 then the value itself, starting on a new line, and terminated by an additional
4629 newline. When we had only numbered ACL variables, the first line might look
4630 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4634 name of the variable
4635 value of the variable
4636 ctx FILE pointer (as a void pointer)
4642 acl_var_write(uschar *name, uschar *value, void *ctx)
4644 FILE *f = (FILE *)ctx;
4645 if (is_tainted(value)) putc('-', f);
4646 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);
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