1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Code for handling Access Control Lists (ACLs) */
13 /* Default callout timeout */
15 #define CALLOUT_TIMEOUT_DEFAULT 30
17 /* ACL verb codes - keep in step with the table of verbs that follows */
19 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
24 static uschar *verbs[] = {
25 [ACL_ACCEPT] = US"accept",
26 [ACL_DEFER] = US"defer",
27 [ACL_DENY] = US"deny",
28 [ACL_DISCARD] = US"discard",
29 [ACL_DROP] = US"drop",
30 [ACL_REQUIRE] = US"require",
34 /* For each verb, the conditions for which "message" or "log_message" are used
35 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
36 "accept", the FAIL case is used only after "endpass", but that is selected in
39 static int msgcond[] = {
40 [ACL_ACCEPT] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
41 [ACL_DEFER] = BIT(OK),
43 [ACL_DISCARD] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
45 [ACL_REQUIRE] = BIT(FAIL) | BIT(FAIL_DROP),
49 /* ACL condition and modifier codes - keep in step with the table that
56 #ifdef EXPERIMENTAL_BRIGHTMAIL
62 #ifdef EXPERIMENTAL_DCC
65 #ifdef WITH_CONTENT_SCAN
73 #ifdef EXPERIMENTAL_DMARC
83 ACLC_LOG_REJECT_TARGET,
85 #ifdef WITH_CONTENT_SCAN
89 #ifdef WITH_CONTENT_SCAN
95 #ifdef WITH_CONTENT_SCAN
102 #ifdef WITH_CONTENT_SCAN
112 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
113 "message", "log_message", "log_reject_target", "logwrite", "queue" and "set" are
114 modifiers that look like conditions but always return TRUE. They are used for
115 their side effects. */
117 typedef struct condition_def {
120 /* Flag to indicate the condition/modifier has a string expansion done
121 at the outer level. In the other cases, expansion already occurs in the
122 checking functions. */
123 BOOL expand_at_top:1;
127 /* Bit map vector of which conditions and modifiers are not allowed at certain
128 times. For each condition and modifier, there's a bitmap of dis-allowed times.
129 For some, it is easier to specify the negation of a small number of allowed
135 static condition_def conditions[] = {
136 [ACLC_ACL] = { US"acl", FALSE, FALSE, 0 },
138 [ACLC_ADD_HEADER] = { US"add_header", TRUE, TRUE,
140 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
141 ACL_BIT_PREDATA | ACL_BIT_DATA |
145 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
147 ACL_BIT_NOTSMTP_START),
150 [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE,
151 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
152 ACL_BIT_CONNECT | ACL_BIT_HELO,
154 #ifdef EXPERIMENTAL_BRIGHTMAIL
155 [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE,
157 ACL_BIT_CONNECT | ACL_BIT_HELO |
158 ACL_BIT_DATA | ACL_BIT_MIME |
159 # ifndef DISABLE_PRDR
162 ACL_BIT_ETRN | ACL_BIT_EXPN |
164 ACL_BIT_MAIL | ACL_BIT_STARTTLS |
165 ACL_BIT_VRFY | ACL_BIT_PREDATA |
166 ACL_BIT_NOTSMTP_START,
169 [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 },
170 [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 },
172 /* Certain types of control are always allowed, so we let it through
173 always and check in the control processing itself. */
174 [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 },
176 #ifdef EXPERIMENTAL_DCC
177 [ACLC_DCC] = { US"dcc", TRUE, FALSE,
180 # ifndef DISABLE_PRDR
186 #ifdef WITH_CONTENT_SCAN
187 [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
190 [ACLC_DELAY] = { US"delay", TRUE, TRUE, ACL_BIT_NOTQUIT },
192 [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
193 [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
195 #ifdef EXPERIMENTAL_DMARC
196 [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DATA },
199 /* Explicit key lookups can be made in non-smtp ACLs so pass
200 always and check in the verify processing itself. */
201 [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 },
203 [ACLC_DOMAINS] = { US"domains", FALSE, FALSE,
205 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
211 [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE,
212 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
216 [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 },
218 [ACLC_HOSTS] = { US"hosts", FALSE, FALSE,
219 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
221 [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE,
223 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
230 [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 },
231 [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 },
232 [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 },
234 #ifdef WITH_CONTENT_SCAN
235 [ACLC_MALWARE] = { US"malware", TRUE, FALSE,
238 # ifndef DISABLE_PRDR
245 [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 },
246 #ifdef WITH_CONTENT_SCAN
247 [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
250 [ACLC_QUEUE] = { US"queue", TRUE, TRUE,
258 [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 },
259 [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~ACL_BIT_RCPT },
261 #ifdef WITH_CONTENT_SCAN
262 [ACLC_REGEX] = { US"regex", TRUE, FALSE,
265 # ifndef DISABLE_PRDR
273 [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE,
275 ~(ACL_BIT_MAIL|ACL_BIT_RCPT |
276 ACL_BIT_PREDATA | ACL_BIT_DATA |
280 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
281 ACL_BIT_NOTSMTP_START),
283 [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE,
284 ACL_BIT_AUTH | ACL_BIT_CONNECT |
286 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
287 ACL_BIT_ETRN | ACL_BIT_EXPN |
288 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
290 [ACLC_SENDERS] = { US"senders", FALSE, FALSE,
291 ACL_BIT_AUTH | ACL_BIT_CONNECT |
293 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
294 ACL_BIT_ETRN | ACL_BIT_EXPN |
295 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
298 [ACLC_SET] = { US"set", TRUE, TRUE, 0 },
300 #ifdef WITH_CONTENT_SCAN
301 [ACLC_SPAM] = { US"spam", TRUE, FALSE,
302 (unsigned int) ~(ACL_BIT_DATA |
303 # ifndef DISABLE_PRDR
310 [ACLC_SPF] = { US"spf", TRUE, FALSE,
311 ACL_BIT_AUTH | ACL_BIT_CONNECT |
312 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
313 ACL_BIT_ETRN | ACL_BIT_EXPN |
314 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
315 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
317 [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE,
318 ACL_BIT_AUTH | ACL_BIT_CONNECT |
319 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
320 ACL_BIT_ETRN | ACL_BIT_EXPN |
321 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
322 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
325 [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 },
327 /* Certain types of verify are always allowed, so we let it through
328 always and check in the verify function itself */
329 [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 },
334 /* Return values from decode_control(); used as index so keep in step
335 with the controls_list table that follows! */
338 CONTROL_AUTH_UNADVERTISED,
339 #ifdef EXPERIMENTAL_BRIGHTMAIL
342 CONTROL_CASEFUL_LOCAL_PART,
343 CONTROL_CASELOWER_LOCAL_PART,
344 CONTROL_CUTTHROUGH_DELIVERY,
349 #ifdef EXPERIMENTAL_DMARC
350 CONTROL_DMARC_VERIFY,
351 CONTROL_DMARC_FORENSIC,
354 CONTROL_ENFORCE_SYNC,
355 CONTROL_ERROR, /* pseudo-value for decode errors */
360 CONTROL_NO_CALLOUT_FLUSH,
361 CONTROL_NO_DELAY_FLUSH,
362 CONTROL_NO_ENFORCE_SYNC,
363 #ifdef WITH_CONTENT_SCAN
364 CONTROL_NO_MBOX_UNSPOOL,
366 CONTROL_NO_MULTILINE,
367 CONTROL_NO_PIPELINING,
370 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
374 CONTROL_SUPPRESS_LOCAL_FIXUPS,
376 CONTROL_UTF8_DOWNCONVERT,
382 /* Structure listing various control arguments, with their characteristics.
383 For each control, there's a bitmap of dis-allowed times. For some, it is easier
384 to specify the negation of a small number of allowed times. */
386 typedef struct control_def {
388 BOOL has_option; /* Has /option(s) following */
389 unsigned forbids; /* bitmap of dis-allowed times */
392 static control_def controls_list[] = {
393 /* name has_option forbids */
394 [CONTROL_AUTH_UNADVERTISED] =
395 { US"allow_auth_unadvertised", FALSE,
397 ~(ACL_BIT_CONNECT | ACL_BIT_HELO)
399 #ifdef EXPERIMENTAL_BRIGHTMAIL
401 { US"bmi_run", FALSE, 0 },
403 [CONTROL_CASEFUL_LOCAL_PART] =
404 { US"caseful_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
405 [CONTROL_CASELOWER_LOCAL_PART] =
406 { US"caselower_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
407 [CONTROL_CUTTHROUGH_DELIVERY] =
408 { US"cutthrough_delivery", TRUE, 0 },
410 { US"debug", TRUE, 0 },
413 [CONTROL_DKIM_VERIFY] =
414 { US"dkim_disable_verify", FALSE,
415 ACL_BIT_DATA | ACL_BIT_NOTSMTP |
416 # ifndef DISABLE_PRDR
419 ACL_BIT_NOTSMTP_START
423 #ifdef EXPERIMENTAL_DMARC
424 [CONTROL_DMARC_VERIFY] =
425 { US"dmarc_disable_verify", FALSE,
426 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
428 [CONTROL_DMARC_FORENSIC] =
429 { US"dmarc_enable_forensic", FALSE,
430 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
436 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | ACL_BIT_NOTQUIT
438 [CONTROL_ENFORCE_SYNC] =
439 { US"enforce_sync", FALSE,
440 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
443 /* Pseudo-value for decode errors */
445 { US"error", FALSE, 0 },
447 [CONTROL_FAKEDEFER] =
448 { US"fakedefer", TRUE,
450 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
451 ACL_BIT_PREDATA | ACL_BIT_DATA |
457 [CONTROL_FAKEREJECT] =
458 { US"fakereject", TRUE,
460 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
461 ACL_BIT_PREDATA | ACL_BIT_DATA |
470 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
471 ACL_BIT_PREDATA | ACL_BIT_DATA |
472 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
473 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
476 [CONTROL_NO_CALLOUT_FLUSH] =
477 { US"no_callout_flush", FALSE,
478 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
480 [CONTROL_NO_DELAY_FLUSH] =
481 { US"no_delay_flush", FALSE,
482 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
485 [CONTROL_NO_ENFORCE_SYNC] =
486 { US"no_enforce_sync", FALSE,
487 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
489 #ifdef WITH_CONTENT_SCAN
490 [CONTROL_NO_MBOX_UNSPOOL] =
491 { US"no_mbox_unspool", FALSE,
493 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
494 ACL_BIT_PREDATA | ACL_BIT_DATA |
495 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
499 [CONTROL_NO_MULTILINE] =
500 { US"no_multiline_responses", FALSE,
501 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
503 [CONTROL_NO_PIPELINING] =
504 { US"no_pipelining", FALSE,
505 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
508 [CONTROL_QUEUE_ONLY] =
509 { US"queue_only", FALSE,
511 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
512 ACL_BIT_PREDATA | ACL_BIT_DATA |
513 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
514 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
518 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
519 [CONTROL_REQUIRETLS] =
520 { US"requiretls", FALSE,
522 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
523 ACL_BIT_DATA | ACL_BIT_MIME |
528 [CONTROL_SUBMISSION] =
529 { US"submission", TRUE,
531 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA)
533 [CONTROL_SUPPRESS_LOCAL_FIXUPS] =
534 { US"suppress_local_fixups", FALSE,
536 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
537 ACL_BIT_NOTSMTP_START)
540 [CONTROL_UTF8_DOWNCONVERT] =
541 { US"utf8_downconvert", TRUE, (unsigned) ~(ACL_BIT_RCPT | ACL_BIT_VRFY)
546 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
547 caches its result in a tree to avoid repeated DNS queries. The result is an
548 integer code which is used as an index into the following tables of
549 explanatory strings and verification return codes. */
551 static tree_node *csa_cache = NULL;
553 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
554 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
556 /* The acl_verify_csa() return code is translated into an acl_verify() return
557 code using the following table. It is OK unless the client is definitely not
558 authorized. This is because CSA is supposed to be optional for sending sites,
559 so recipients should not be too strict about checking it - especially because
560 DNS problems are quite likely to occur. It's possible to use $csa_status in
561 further ACL conditions to distinguish ok, unknown, and defer if required, but
562 the aim is to make the usual configuration simple. */
564 static int csa_return_code[] = {
567 [CSA_DEFER_SRV] = OK,
568 [CSA_DEFER_ADDR] = OK,
569 [CSA_FAIL_EXPLICIT] = FAIL,
570 [CSA_FAIL_DOMAIN] = FAIL,
571 [CSA_FAIL_NOADDR] = FAIL,
572 [CSA_FAIL_MISMATCH] = FAIL
575 static uschar *csa_status_string[] = {
576 [CSA_UNKNOWN] = US"unknown",
578 [CSA_DEFER_SRV] = US"defer",
579 [CSA_DEFER_ADDR] = US"defer",
580 [CSA_FAIL_EXPLICIT] = US"fail",
581 [CSA_FAIL_DOMAIN] = US"fail",
582 [CSA_FAIL_NOADDR] = US"fail",
583 [CSA_FAIL_MISMATCH] = US"fail"
586 static uschar *csa_reason_string[] = {
587 [CSA_UNKNOWN] = US"unknown",
589 [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)",
590 [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)",
591 [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)",
592 [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)",
593 [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)",
594 [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)"
597 /* Options for the ratelimit condition. Note that there are two variants of
598 the per_rcpt option, depending on the ACL that is used to measure the rate.
599 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
600 so the two variants must have the same internal representation as well as
601 the same configuration string. */
604 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
605 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
608 #define RATE_SET(var,new) \
609 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
611 static uschar *ratelimit_option_string[] = {
612 [RATE_PER_WHAT] = US"?",
613 [RATE_PER_CLASH] = US"!",
614 [RATE_PER_ADDR] = US"per_addr",
615 [RATE_PER_BYTE] = US"per_byte",
616 [RATE_PER_CMD] = US"per_cmd",
617 [RATE_PER_CONN] = US"per_conn",
618 [RATE_PER_MAIL] = US"per_mail",
619 [RATE_PER_RCPT] = US"per_rcpt",
620 [RATE_PER_ALLRCPTS] = US"per_rcpt"
623 /* Enable recursion between acl_check_internal() and acl_check_condition() */
625 static int acl_check_wargs(int, address_item *, const uschar *, uschar **,
629 /*************************************************
630 * Find control in list *
631 *************************************************/
633 /* The lists are always in order, so binary chop can be used.
636 name the control name to search for
637 ol the first entry in the control list
638 last one more than the offset of the last entry in the control list
640 Returns: index of a control entry, or -1 if not found
644 find_control(const uschar * name, control_def * ol, int last)
649 int middle = (first + last)/2;
650 uschar * s = ol[middle].name;
651 int c = Ustrncmp(name, s, Ustrlen(s));
652 if (c == 0) return middle;
653 else if (c > 0) first = middle + 1;
661 /*************************************************
662 * Pick out condition from list *
663 *************************************************/
665 /* Use a binary chop method
669 list list of conditions
672 Returns: offset in list, or -1 if not found
676 acl_checkcondition(uschar * name, condition_def * list, int end)
681 int mid = (start + end)/2;
682 int c = Ustrcmp(name, list[mid].name);
683 if (c == 0) return mid;
684 if (c < 0) end = mid;
685 else start = mid + 1;
691 /*************************************************
692 * Pick out name from list *
693 *************************************************/
695 /* Use a binary chop method
702 Returns: offset in list, or -1 if not found
706 acl_checkname(uschar *name, uschar **list, int end)
712 int mid = (start + end)/2;
713 int c = Ustrcmp(name, list[mid]);
714 if (c == 0) return mid;
715 if (c < 0) end = mid; else start = mid + 1;
722 /*************************************************
723 * Read and parse one ACL *
724 *************************************************/
726 /* This function is called both from readconf in order to parse the ACLs in the
727 configuration file, and also when an ACL is encountered dynamically (e.g. as
728 the result of an expansion). It is given a function to call in order to
729 retrieve the lines of the ACL. This function handles skipping comments and
730 blank lines (where relevant).
733 func function to get next line of ACL
734 error where to put an error message
736 Returns: pointer to ACL, or NULL
737 NULL can be legal (empty ACL); in this case error will be NULL
741 acl_read(uschar *(*func)(void), uschar **error)
743 acl_block *yield = NULL;
744 acl_block **lastp = &yield;
745 acl_block *this = NULL;
746 acl_condition_block *cond;
747 acl_condition_block **condp = NULL;
752 while ((s = (*func)()) != NULL)
755 BOOL negated = FALSE;
756 uschar *saveline = s;
759 /* Conditions (but not verbs) are allowed to be negated by an initial
762 while (isspace(*s)) s++;
769 /* Read the name of a verb or a condition, or the start of a new ACL, which
770 can be started by a name, or by a macro definition. */
772 s = readconf_readname(name, sizeof(name), s);
773 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
775 /* If a verb is unrecognized, it may be another condition or modifier that
776 continues the previous verb. */
778 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
782 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
794 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
797 this = store_get(sizeof(acl_block));
799 lastp = &(this->next);
802 this->condition = NULL;
803 condp = &(this->condition);
804 if (*s == 0) continue; /* No condition on this line */
810 s = readconf_readname(name, sizeof(name), s); /* Condition name */
813 /* Handle a condition or modifier. */
815 if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0)
817 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
822 /* The modifiers may not be negated */
824 if (negated && conditions[c].is_modifier)
826 *error = string_sprintf("ACL error: negation is not allowed with "
827 "\"%s\"", conditions[c].name);
831 /* ENDPASS may occur only with ACCEPT or DISCARD. */
833 if (c == ACLC_ENDPASS &&
834 this->verb != ACL_ACCEPT &&
835 this->verb != ACL_DISCARD)
837 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
838 conditions[c].name, verbs[this->verb]);
842 cond = store_get(sizeof(acl_condition_block));
845 cond->u.negated = negated;
848 condp = &(cond->next);
850 /* The "set" modifier is different in that its argument is "name=value"
851 rather than just a value, and we can check the validity of the name, which
852 gives us a variable name to insert into the data block. The original ACL
853 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
854 extended to 20 of each type, but after that people successfully argued for
855 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
856 After that, we allow alphanumerics and underscores, but the first character
857 after c or m must be a digit or an underscore. This retains backwards
862 if ( Ustrncmp(s, "dkim_verify_status", 18) == 0
863 || Ustrncmp(s, "dkim_verify_reason", 18) == 0)
865 uschar * endptr = s+18;
867 if (isalnum(*endptr))
869 *error = string_sprintf("invalid variable name after \"set\" in ACL "
870 "modifier \"set %s\" "
871 "(only \"dkim_verify_status\" or \"dkim_verify_reason\" permitted)",
875 cond->u.varname = string_copyn(s, 18);
877 while (isspace(*s)) s++;
884 if (Ustrncmp(s, "acl_c", 5) != 0 &&
885 Ustrncmp(s, "acl_m", 5) != 0)
887 *error = string_sprintf("invalid variable name after \"set\" in ACL "
888 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
893 if (!isdigit(*endptr) && *endptr != '_')
895 *error = string_sprintf("invalid variable name after \"set\" in ACL "
896 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
901 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
903 if (!isalnum(*endptr) && *endptr != '_')
905 *error = string_sprintf("invalid character \"%c\" in variable name "
906 "in ACL modifier \"set %s\"", *endptr, s);
912 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
914 while (isspace(*s)) s++;
917 /* For "set", we are now positioned for the data. For the others, only
918 "endpass" has no data */
920 if (c != ACLC_ENDPASS)
924 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
925 conditions[c].is_modifier ? US"modifier" : US"condition");
928 while (isspace(*s)) s++;
929 cond->arg = string_copy(s);
938 /*************************************************
939 * Set up added header line(s) *
940 *************************************************/
942 /* This function is called by the add_header modifier, and also from acl_warn()
943 to implement the now-deprecated way of adding header lines using "message" on a
944 "warn" verb. The argument is treated as a sequence of header lines which are
945 added to a chain, provided there isn't an identical one already there.
947 Argument: string of header lines
952 setup_header(const uschar *hstring)
955 int hlen = Ustrlen(hstring);
957 /* Ignore any leading newlines */
958 while (*hstring == '\n') hstring++, hlen--;
960 /* An empty string does nothing; ensure exactly one final newline. */
961 if (hlen <= 0) return;
962 if (hstring[--hlen] != '\n') /* no newline */
963 q = string_sprintf("%s\n", hstring);
964 else if (hstring[hlen-1] == '\n') /* double newline */
966 uschar * s = string_copy(hstring);
967 while(s[--hlen] == '\n')
974 /* Loop for multiple header lines, taking care about continuations */
976 for (p = q; *p; p = q)
980 int newtype = htype_add_bot;
981 header_line **hptr = &acl_added_headers;
983 /* Find next header line within the string */
987 q = Ustrchr(q, '\n'); /* we know there was a newline */
988 if (*++q != ' ' && *q != '\t') break;
991 /* If the line starts with a colon, interpret the instruction for where to
992 add it. This temporarily sets up a new type. */
996 if (strncmpic(p, US":after_received:", 16) == 0)
998 newtype = htype_add_rec;
1001 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
1003 newtype = htype_add_rfc;
1006 else if (strncmpic(p, US":at_start:", 10) == 0)
1008 newtype = htype_add_top;
1011 else if (strncmpic(p, US":at_end:", 8) == 0)
1013 newtype = htype_add_bot;
1016 while (*p == ' ' || *p == '\t') p++;
1019 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1020 to the front of it. */
1022 for (s = p; s < q - 1; s++)
1023 if (*s == ':' || !isgraph(*s)) break;
1025 hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p);
1026 hlen = Ustrlen(hdr);
1028 /* See if this line has already been added */
1032 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1033 hptr = &(*hptr)->next;
1036 /* Add if not previously present */
1040 header_line *h = store_get(sizeof(header_line));
1053 /*************************************************
1054 * List the added header lines *
1055 *************************************************/
1062 for (h = acl_added_headers; h; h = h->next)
1065 if (h->text[i-1] == '\n') i--;
1066 g = string_append_listele_n(g, '\n', h->text, i);
1069 return g ? g->s : NULL;
1073 /*************************************************
1074 * Set up removed header line(s) *
1075 *************************************************/
1077 /* This function is called by the remove_header modifier. The argument is
1078 treated as a sequence of header names which are added to a colon separated
1079 list, provided there isn't an identical one already there.
1081 Argument: string of header names
1086 setup_remove_header(const uschar *hnames)
1089 acl_removed_headers = acl_removed_headers
1090 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1091 : string_copy(hnames);
1096 /*************************************************
1098 *************************************************/
1100 /* This function is called when a WARN verb's conditions are true. It adds to
1101 the message's headers, and/or writes information to the log. In each case, this
1102 only happens once (per message for headers, per connection for log).
1104 ** NOTE: The header adding action using the "message" setting is historic, and
1105 its use is now deprecated. The new add_header modifier should be used instead.
1108 where ACL_WHERE_xxxx indicating which ACL this is
1109 user_message message for adding to headers
1110 log_message message for logging, if different
1116 acl_warn(int where, uschar *user_message, uschar *log_message)
1118 if (log_message != NULL && log_message != user_message)
1121 string_item *logged;
1123 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1124 string_printing(log_message));
1126 /* If a sender verification has failed, and the log message is "sender verify
1127 failed", add the failure message. */
1129 if (sender_verified_failed != NULL &&
1130 sender_verified_failed->message != NULL &&
1131 strcmpic(log_message, US"sender verify failed") == 0)
1132 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1134 /* Search previously logged warnings. They are kept in malloc
1135 store so they can be freed at the start of a new message. */
1137 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1138 if (Ustrcmp(logged->text, text) == 0) break;
1142 int length = Ustrlen(text) + 1;
1143 log_write(0, LOG_MAIN, "%s", text);
1144 logged = store_malloc(sizeof(string_item) + length);
1145 logged->text = US logged + sizeof(string_item);
1146 memcpy(logged->text, text, length);
1147 logged->next = acl_warn_logged;
1148 acl_warn_logged = logged;
1152 /* If there's no user message, we are done. */
1154 if (user_message == NULL) return;
1156 /* If this isn't a message ACL, we can't do anything with a user message.
1159 if (where > ACL_WHERE_NOTSMTP)
1161 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1162 "found in a non-message (%s) ACL: cannot specify header lines here: "
1163 "message ignored", acl_wherenames[where]);
1167 /* The code for setting up header lines is now abstracted into a separate
1168 function so that it can be used for the add_header modifier as well. */
1170 setup_header(user_message);
1175 /*************************************************
1176 * Verify and check reverse DNS *
1177 *************************************************/
1179 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1180 address if this has not yet been done. The host_name_lookup() function checks
1181 that one of these names resolves to an address list that contains the client IP
1182 address, so we don't actually have to do the check here.
1185 user_msgptr pointer for user message
1186 log_msgptr pointer for log message
1188 Returns: OK verification condition succeeded
1189 FAIL verification failed
1190 DEFER there was a problem verifying
1194 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1198 user_msgptr = user_msgptr; /* stop compiler warning */
1200 /* Previous success */
1202 if (sender_host_name != NULL) return OK;
1204 /* Previous failure */
1206 if (host_lookup_failed)
1208 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1212 /* Need to do a lookup */
1215 debug_printf_indent("looking up host name to force name/address consistency check\n");
1217 if ((rc = host_name_lookup()) != OK)
1219 *log_msgptr = (rc == DEFER)?
1220 US"host lookup deferred for reverse lookup check"
1222 string_sprintf("host lookup failed for reverse lookup check%s",
1224 return rc; /* DEFER or FAIL */
1227 host_build_sender_fullhost();
1233 /*************************************************
1234 * Check client IP address matches CSA target *
1235 *************************************************/
1237 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1238 response for address records belonging to the CSA target hostname. The section
1239 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1240 If one of the addresses matches the client's IP address, then the client is
1241 authorized by CSA. If there are target IP addresses but none of them match
1242 then the client is using an unauthorized IP address. If there are no target IP
1243 addresses then the client cannot be using an authorized IP address. (This is
1244 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1247 dnsa the DNS answer block
1248 dnss a DNS scan block for us to use
1249 reset option specifying what portion to scan, as described above
1250 target the target hostname to use for matching RR names
1252 Returns: CSA_OK successfully authorized
1253 CSA_FAIL_MISMATCH addresses found but none matched
1254 CSA_FAIL_NOADDR no target addresses found
1258 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1264 BOOL target_found = FALSE;
1266 for (rr = dns_next_rr(dnsa, dnss, reset);
1268 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1270 /* Check this is an address RR for the target hostname. */
1274 && rr->type != T_AAAA
1278 if (strcmpic(target, rr->name) != 0) continue;
1280 target_found = TRUE;
1282 /* Turn the target address RR into a list of textual IP addresses and scan
1283 the list. There may be more than one if it is an A6 RR. */
1285 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1287 /* If the client IP address matches the target IP address, it's good! */
1289 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1291 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1295 /* If we found some target addresses but none of them matched, the client is
1296 using an unauthorized IP address, otherwise the target has no authorized IP
1299 if (target_found) return CSA_FAIL_MISMATCH;
1300 else return CSA_FAIL_NOADDR;
1305 /*************************************************
1306 * Verify Client SMTP Authorization *
1307 *************************************************/
1309 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1310 to find the CSA SRV record corresponding to the domain argument, or
1311 $sender_helo_name if no argument is provided. It then checks that the
1312 client is authorized, and that its IP address corresponds to the SRV
1313 target's address by calling acl_verify_csa_address() above. The address
1314 should have been returned in the DNS response's ADDITIONAL section, but if
1315 not we perform another DNS lookup to get it.
1318 domain pointer to optional parameter following verify = csa
1320 Returns: CSA_UNKNOWN no valid CSA record found
1321 CSA_OK successfully authorized
1322 CSA_FAIL_* client is definitely not authorized
1323 CSA_DEFER_* there was a DNS problem
1327 acl_verify_csa(const uschar *domain)
1330 const uschar *found;
1331 int priority, weight, port;
1338 /* Work out the domain we are using for the CSA lookup. The default is the
1339 client's HELO domain. If the client has not said HELO, use its IP address
1340 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1342 while (isspace(*domain) && *domain != '\0') ++domain;
1343 if (*domain == '\0') domain = sender_helo_name;
1344 if (domain == NULL) domain = sender_host_address;
1345 if (sender_host_address == NULL) return CSA_UNKNOWN;
1347 /* If we have an address literal, strip off the framing ready for turning it
1348 into a domain. The framing consists of matched square brackets possibly
1349 containing a keyword and a colon before the actual IP address. */
1351 if (domain[0] == '[')
1353 const uschar *start = Ustrchr(domain, ':');
1354 if (start == NULL) start = domain;
1355 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1358 /* Turn domains that look like bare IP addresses into domains in the reverse
1359 DNS. This code also deals with address literals and $sender_host_address. It's
1360 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1361 address literals, but it's probably the most friendly thing to do. This is an
1362 extension to CSA, so we allow it to be turned off for proper conformance. */
1364 if (string_is_ip_address(domain, NULL) != 0)
1366 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1367 dns_build_reverse(domain, target);
1371 /* Find out if we've already done the CSA check for this domain. If we have,
1372 return the same result again. Otherwise build a new cached result structure
1373 for this domain. The name is filled in now, and the value is filled in when
1374 we return from this function. */
1376 t = tree_search(csa_cache, domain);
1377 if (t != NULL) return t->data.val;
1379 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1380 Ustrcpy(t->name, domain);
1381 (void)tree_insertnode(&csa_cache, t);
1383 /* Now we are ready to do the actual DNS lookup(s). */
1386 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1388 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1391 return t->data.val = CSA_DEFER_SRV;
1393 /* If we found nothing, the client's authorization is unknown. */
1397 return t->data.val = CSA_UNKNOWN;
1399 /* We got something! Go on to look at the reply in more detail. */
1405 /* Scan the reply for well-formed CSA SRV records. */
1407 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1409 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1411 const uschar * p = rr->data;
1413 /* Extract the numerical SRV fields (p is incremented) */
1415 GETSHORT(priority, p);
1416 GETSHORT(weight, p);
1420 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1422 /* Check the CSA version number */
1424 if (priority != 1) continue;
1426 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1427 found by dns_special_lookup() is a parent of the one we asked for), we check
1428 the subdomain assertions in the port field. At the moment there's only one
1429 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1430 SRV records of their own. */
1432 if (Ustrcmp(found, domain) != 0)
1433 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1435 /* This CSA SRV record refers directly to our domain, so we check the value
1436 in the weight field to work out the domain's authorization. 0 and 1 are
1437 unauthorized; 3 means the client is authorized but we can't check the IP
1438 address in order to authenticate it, so we treat it as unknown; values
1439 greater than 3 are undefined. */
1441 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1443 if (weight > 2) continue;
1445 /* Weight == 2, which means the domain is authorized. We must check that the
1446 client's IP address is listed as one of the SRV target addresses. Save the
1447 target hostname then break to scan the additional data for its addresses. */
1449 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1450 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1452 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1457 /* If we didn't break the loop then no appropriate records were found. */
1459 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1461 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1462 A target of "." indicates there are no valid addresses, so the client cannot
1463 be authorized. (This is an odd configuration because weight=2 target=. is
1464 equivalent to weight=1, but we check for it in order to keep load off the
1465 root name servers.) Note that dn_expand() turns "." into "". */
1467 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1469 /* Scan the additional section of the CSA SRV reply for addresses belonging
1470 to the target. If the name server didn't return any additional data (e.g.
1471 because it does not fully support SRV records), we need to do another lookup
1472 to obtain the target addresses; otherwise we have a definitive result. */
1474 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1475 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1477 /* The DNS lookup type corresponds to the IP version used by the client. */
1480 if (Ustrchr(sender_host_address, ':') != NULL)
1483 #endif /* HAVE_IPV6 */
1487 lookup_dnssec_authenticated = NULL;
1488 switch (dns_lookup(&dnsa, target, type, NULL))
1490 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1493 return t->data.val = CSA_DEFER_ADDR;
1495 /* If the query succeeded, scan the addresses and return the result. */
1498 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1499 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1500 /* else fall through */
1502 /* If the target has no IP addresses, the client cannot have an authorized
1503 IP address. However, if the target site uses A6 records (not AAAA records)
1504 we have to do yet another lookup in order to check them. */
1508 return t->data.val = CSA_FAIL_NOADDR;
1514 /*************************************************
1515 * Handle verification (address & other) *
1516 *************************************************/
1518 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1519 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1520 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1525 unsigned where_allowed; /* bitmap */
1526 BOOL no_options; /* Never has /option(s) following */
1527 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1529 static verify_type_t verify_type_list[] = {
1530 /* name value where no-opt opt-sep */
1531 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, FALSE, 0 },
1532 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1533 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1534 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1535 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1536 { US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1537 { US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1538 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1539 |ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1541 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1542 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1543 #ifdef EXPERIMENTAL_ARC
1544 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1549 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1550 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1551 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1552 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1558 BOOL has_option; /* Has =option(s) following */
1559 BOOL timeval; /* Has a time value */
1561 static callout_opt_t callout_opt_list[] = {
1562 /* name value flag has-opt has-time */
1563 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1564 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1565 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1566 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1567 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1568 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1569 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1570 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1571 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1572 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1573 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1574 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1575 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1580 /* This function implements the "verify" condition. It is called when
1581 encountered in any ACL, because some tests are almost always permitted. Some
1582 just don't make sense, and always fail (for example, an attempt to test a host
1583 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1586 where where called from
1587 addr the recipient address that the ACL is handling, or NULL
1588 arg the argument of "verify"
1589 user_msgptr pointer for user message
1590 log_msgptr pointer for log message
1591 basic_errno where to put verify errno
1593 Returns: OK verification condition succeeded
1594 FAIL verification failed
1595 DEFER there was a problem verifying
1600 acl_verify(int where, address_item *addr, const uschar *arg,
1601 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1605 int callout_overall = -1;
1606 int callout_connect = -1;
1607 int verify_options = 0;
1609 BOOL verify_header_sender = FALSE;
1610 BOOL defer_ok = FALSE;
1611 BOOL callout_defer_ok = FALSE;
1612 BOOL no_details = FALSE;
1613 BOOL success_on_redirect = FALSE;
1614 address_item *sender_vaddr = NULL;
1615 uschar *verify_sender_address = NULL;
1616 uschar *pm_mailfrom = NULL;
1617 uschar *se_mailfrom = NULL;
1619 /* Some of the verify items have slash-separated options; some do not. Diagnose
1620 an error if options are given for items that don't expect them.
1623 uschar *slash = Ustrchr(arg, '/');
1624 const uschar *list = arg;
1625 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1628 if (!ss) goto BAD_VERIFY;
1630 /* Handle name/address consistency verification in a separate function. */
1632 for (vp= verify_type_list;
1633 CS vp < CS verify_type_list + sizeof(verify_type_list);
1636 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1637 : strcmpic (ss, vp->name) == 0)
1639 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1642 if (vp->no_options && slash)
1644 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1645 "(this verify item has no options)", arg);
1648 if (!(vp->where_allowed & BIT(where)))
1650 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1651 vp->name, acl_wherenames[where]);
1656 case VERIFY_REV_HOST_LKUP:
1657 if (!sender_host_address) return OK;
1658 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1659 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1660 if (strcmpic(ss, US"defer_ok") == 0)
1665 /* TLS certificate verification is done at STARTTLS time; here we just
1666 test whether it was successful or not. (This is for optional verification; for
1667 mandatory verification, the connection doesn't last this long.) */
1669 if (tls_in.certificate_verified) return OK;
1670 *user_msgptr = US"no verified certificate";
1674 /* We can test the result of optional HELO verification that might have
1675 occurred earlier. If not, we can attempt the verification now. */
1677 if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo();
1678 return f.helo_verified ? OK : FAIL;
1681 /* Do Client SMTP Authorization checks in a separate function, and turn the
1682 result code into user-friendly strings. */
1684 rc = acl_verify_csa(list);
1685 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1686 csa_reason_string[rc]);
1687 csa_status = csa_status_string[rc];
1688 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1689 return csa_return_code[rc];
1691 #ifdef EXPERIMENTAL_ARC
1693 { /* Do Authenticated Received Chain checks in a separate function. */
1694 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1698 if (!(arc_state = acl_verify_arc())) return DEFER;
1699 DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state,
1700 arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":"");
1702 if (!condlist) condlist = US"none:pass";
1703 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1704 if (Ustrcmp(arc_state, cond) == 0) return OK;
1709 case VERIFY_HDR_SYNTAX:
1710 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1711 a syntax error, we return details of the error to the sender if configured to
1712 send out full details. (But a "message" setting on the ACL can override, as
1715 rc = verify_check_headers(log_msgptr);
1716 if (rc != OK && *log_msgptr)
1717 if (smtp_return_error_details)
1718 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1720 acl_verify_message = *log_msgptr;
1723 case VERIFY_HDR_NAMES_ASCII:
1724 /* Check that all header names are true 7 bit strings
1725 See RFC 5322, 2.2. and RFC 6532, 3. */
1727 rc = verify_check_header_names_ascii(log_msgptr);
1728 if (rc != OK && smtp_return_error_details && *log_msgptr)
1729 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1732 case VERIFY_NOT_BLIND:
1733 /* Check that no recipient of this message is "blind", that is, every envelope
1734 recipient must be mentioned in either To: or Cc:. */
1736 if ((rc = verify_check_notblind()) != OK)
1738 *log_msgptr = string_sprintf("bcc recipient detected");
1739 if (smtp_return_error_details)
1740 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1744 /* The remaining verification tests check recipient and sender addresses,
1745 either from the envelope or from the header. There are a number of
1746 slash-separated options that are common to all of them. */
1748 case VERIFY_HDR_SNDR:
1749 verify_header_sender = TRUE;
1753 /* In the case of a sender, this can optionally be followed by an address to use
1754 in place of the actual sender (rare special-case requirement). */
1758 verify_sender_address = sender_address;
1761 while (isspace(*s)) s++;
1762 if (*s++ != '=') goto BAD_VERIFY;
1763 while (isspace(*s)) s++;
1764 verify_sender_address = string_copy(s);
1775 /* Remaining items are optional; they apply to sender and recipient
1776 verification, including "header sender" verification. */
1778 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1781 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1782 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1783 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1785 /* These two old options are left for backwards compatibility */
1787 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1789 callout_defer_ok = TRUE;
1790 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1793 else if (strcmpic(ss, US"check_postmaster") == 0)
1796 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1799 /* The callout option has a number of sub-options, comma separated */
1801 else if (strncmpic(ss, US"callout", 7) == 0)
1803 callout = CALLOUT_TIMEOUT_DEFAULT;
1807 while (isspace(*ss)) ss++;
1810 const uschar * sublist = ss;
1814 while (isspace(*sublist)) sublist++;
1816 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1819 double period = 1.0F;
1821 for (op= callout_opt_list; op->name; op++)
1822 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1825 verify_options |= op->flag;
1828 opt += Ustrlen(op->name);
1829 while (isspace(*opt)) opt++;
1832 *log_msgptr = string_sprintf("'=' expected after "
1833 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1836 while (isspace(*opt)) opt++;
1838 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1840 *log_msgptr = string_sprintf("bad time value in ACL condition "
1841 "\"verify %s\"", arg);
1847 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1848 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1849 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1850 case CALLOUT_MAILFROM:
1851 if (!verify_header_sender)
1853 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1854 "callout option only for verify=header_sender (detected in ACL "
1855 "condition \"%s\")", arg);
1858 se_mailfrom = string_copy(opt);
1860 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1861 case CALLOUT_MAXWAIT: callout_overall = period; break;
1862 case CALLOUT_CONNECT: callout_connect = period; break;
1863 case CALLOUT_TIME: callout = period; break;
1869 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1870 "ACL condition \"%s\"", arg);
1876 /* Option not recognized */
1880 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1881 "condition \"verify %s\"", ss, arg);
1886 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1887 (vopt_callout_recipsender|vopt_callout_recippmaster))
1889 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1890 "for a recipient callout";
1894 /* Handle sender-in-header verification. Default the user message to the log
1895 message if giving out verification details. */
1897 if (verify_header_sender)
1901 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1902 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1905 *basic_errno = verrno;
1906 if (smtp_return_error_details)
1908 if (!*user_msgptr && *log_msgptr)
1909 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1910 if (rc == DEFER) f.acl_temp_details = TRUE;
1915 /* Handle a sender address. The default is to verify *the* sender address, but
1916 optionally a different address can be given, for special requirements. If the
1917 address is empty, we are dealing with a bounce message that has no sender, so
1918 we cannot do any checking. If the real sender address gets rewritten during
1919 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1920 during message reception.
1922 A list of verified "sender" addresses is kept to try to avoid doing to much
1923 work repetitively when there are multiple recipients in a message and they all
1924 require sender verification. However, when callouts are involved, it gets too
1925 complicated because different recipients may require different callout options.
1926 Therefore, we always do a full sender verify when any kind of callout is
1927 specified. Caching elsewhere, for instance in the DNS resolver and in the
1928 callout handling, should ensure that this is not terribly inefficient. */
1930 else if (verify_sender_address)
1932 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1934 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1935 "sender verify callout";
1939 sender_vaddr = verify_checked_sender(verify_sender_address);
1940 if (sender_vaddr != NULL && /* Previously checked */
1941 callout <= 0) /* No callout needed this time */
1943 /* If the "routed" flag is set, it means that routing worked before, so
1944 this check can give OK (the saved return code value, if set, belongs to a
1945 callout that was done previously). If the "routed" flag is not set, routing
1946 must have failed, so we use the saved return code. */
1948 if (testflag(sender_vaddr, af_verify_routed))
1952 rc = sender_vaddr->special_action;
1953 *basic_errno = sender_vaddr->basic_errno;
1955 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1958 /* Do a new verification, and cache the result. The cache is used to avoid
1959 verifying the sender multiple times for multiple RCPTs when callouts are not
1960 specified (see comments above).
1962 The cache is also used on failure to give details in response to the first
1963 RCPT that gets bounced for this reason. However, this can be suppressed by
1964 the no_details option, which sets the flag that says "this detail has already
1965 been sent". The cache normally contains just one address, but there may be
1966 more in esoteric circumstances. */
1971 uschar *save_address_data = deliver_address_data;
1973 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1975 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1977 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1978 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1981 if (no_details) setflag(sender_vaddr, af_sverify_told);
1982 if (verify_sender_address[0] != 0)
1984 /* If this is the real sender address, save the unrewritten version
1985 for use later in receive. Otherwise, set a flag so that rewriting the
1986 sender in verify_address() does not update sender_address. */
1988 if (verify_sender_address == sender_address)
1989 sender_address_unrewritten = sender_address;
1991 verify_options |= vopt_fake_sender;
1993 if (success_on_redirect)
1994 verify_options |= vopt_success_on_redirect;
1996 /* The recipient, qualify, and expn options are never set in
1999 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2000 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2002 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2005 *basic_errno = sender_vaddr->basic_errno;
2009 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2010 debug_printf_indent("sender %s verified ok as %s\n",
2011 verify_sender_address, sender_vaddr->address);
2013 debug_printf_indent("sender %s verified ok\n",
2014 verify_sender_address);
2018 rc = OK; /* Null sender */
2020 /* Cache the result code */
2022 if (routed) setflag(sender_vaddr, af_verify_routed);
2023 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2024 sender_vaddr->special_action = rc;
2025 sender_vaddr->next = sender_verified_list;
2026 sender_verified_list = sender_vaddr;
2028 /* Restore the recipient address data, which might have been clobbered by
2029 the sender verification. */
2031 deliver_address_data = save_address_data;
2034 /* Put the sender address_data value into $sender_address_data */
2036 sender_address_data = sender_vaddr->prop.address_data;
2039 /* A recipient address just gets a straightforward verify; again we must handle
2040 the DEFER overrides. */
2046 if (success_on_redirect)
2047 verify_options |= vopt_success_on_redirect;
2049 /* We must use a copy of the address for verification, because it might
2053 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2054 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2055 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2057 *basic_errno = addr2.basic_errno;
2058 *log_msgptr = addr2.message;
2059 *user_msgptr = (addr2.user_message != NULL)?
2060 addr2.user_message : addr2.message;
2062 /* Allow details for temporary error if the address is so flagged. */
2063 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2065 /* Make $address_data visible */
2066 deliver_address_data = addr2.prop.address_data;
2069 /* We have a result from the relevant test. Handle defer overrides first. */
2071 if (rc == DEFER && (defer_ok ||
2072 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2074 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2075 defer_ok? "defer_ok" : "callout_defer_ok");
2079 /* If we've failed a sender, set up a recipient message, and point
2080 sender_verified_failed to the address item that actually failed. */
2082 if (rc != OK && verify_sender_address != NULL)
2085 *log_msgptr = *user_msgptr = US"Sender verify failed";
2086 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2087 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2090 *log_msgptr = US"Could not complete sender verify callout";
2091 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2095 sender_verified_failed = sender_vaddr;
2098 /* Verifying an address messes up the values of $domain and $local_part,
2099 so reset them before returning if this is a RCPT ACL. */
2103 deliver_domain = addr->domain;
2104 deliver_localpart = addr->local_part;
2108 /* Syntax errors in the verify argument come here. */
2111 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2112 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2113 "or \"reverse_host_lookup\" at start of ACL condition "
2114 "\"verify %s\"", arg);
2121 /*************************************************
2122 * Check argument for control= modifier *
2123 *************************************************/
2125 /* Called from acl_check_condition() below
2128 arg the argument string for control=
2129 pptr set to point to the terminating character
2130 where which ACL we are in
2131 log_msgptr for error messages
2133 Returns: CONTROL_xxx value
2137 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2142 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2143 || ( arg[len = Ustrlen((d = controls_list+idx)->name)] != 0
2144 && (!d->has_option || arg[len] != '/')
2147 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2148 return CONTROL_ERROR;
2158 /*************************************************
2159 * Return a ratelimit error *
2160 *************************************************/
2162 /* Called from acl_ratelimit() below
2165 log_msgptr for error messages
2166 format format string
2167 ... supplementary arguments
2173 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2176 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2177 va_start(ap, format);
2178 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2179 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2180 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2182 *log_msgptr = string_sprintf(
2183 "error in arguments to \"ratelimit\" condition: %s", buffer);
2190 /*************************************************
2191 * Handle rate limiting *
2192 *************************************************/
2194 /* Called by acl_check_condition() below to calculate the result
2195 of the ACL ratelimit condition.
2197 Note that the return value might be slightly unexpected: if the
2198 sender's rate is above the limit then the result is OK. This is
2199 similar to the dnslists condition, and is so that you can write
2200 ACL clauses like: defer ratelimit = 15 / 1h
2203 arg the option string for ratelimit=
2204 where ACL_WHERE_xxxx indicating which ACL this is
2205 log_msgptr for error messages
2207 Returns: OK - Sender's rate is above limit
2208 FAIL - Sender's rate is below limit
2209 DEFER - Problem opening ratelimit database
2210 ERROR - Syntax error in options.
2214 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2216 double limit, period, count;
2219 uschar *unique = NULL;
2221 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2222 BOOL noupdate = FALSE, badacl = FALSE;
2223 int mode = RATE_PER_WHAT;
2225 tree_node **anchor, *t;
2226 open_db dbblock, *dbm;
2228 dbdata_ratelimit *dbd;
2229 dbdata_ratelimit_unique *dbdb;
2232 /* Parse the first two options and record their values in expansion
2233 variables. These variables allow the configuration to have informative
2234 error messages based on rate limits obtained from a table lookup. */
2236 /* First is the maximum number of messages per period / maximum burst
2237 size, which must be greater than or equal to zero. Zero is useful for
2238 rate measurement as opposed to rate limiting. */
2240 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2241 return ratelimit_error(log_msgptr, "sender rate limit not set");
2243 limit = Ustrtod(sender_rate_limit, &ss);
2244 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2245 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2246 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2248 if (limit < 0.0 || *ss != '\0')
2249 return ratelimit_error(log_msgptr,
2250 "\"%s\" is not a positive number", sender_rate_limit);
2252 /* Second is the rate measurement period / exponential smoothing time
2253 constant. This must be strictly greater than zero, because zero leads to
2254 run-time division errors. */
2256 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2257 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2259 return ratelimit_error(log_msgptr,
2260 "\"%s\" is not a time value", sender_rate_period);
2262 /* By default we are counting one of something, but the per_rcpt,
2263 per_byte, and count options can change this. */
2267 /* Parse the other options. */
2269 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)))
2271 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2272 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2273 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2274 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2275 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2276 else if (strcmpic(ss, US"per_conn") == 0)
2278 RATE_SET(mode, PER_CONN);
2279 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2282 else if (strcmpic(ss, US"per_mail") == 0)
2284 RATE_SET(mode, PER_MAIL);
2285 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2287 else if (strcmpic(ss, US"per_rcpt") == 0)
2289 /* If we are running in the RCPT ACL, then we'll count the recipients
2290 one by one, but if we are running when we have accumulated the whole
2291 list then we'll add them all in one batch. */
2292 if (where == ACL_WHERE_RCPT)
2293 RATE_SET(mode, PER_RCPT);
2294 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2295 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2296 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2297 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2299 else if (strcmpic(ss, US"per_byte") == 0)
2301 /* If we have not yet received the message data and there was no SIZE
2302 declaration on the MAIL command, then it's safe to just use a value of
2303 zero and let the recorded rate decay as if nothing happened. */
2304 RATE_SET(mode, PER_MAIL);
2305 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2306 else count = message_size < 0 ? 0.0 : (double)message_size;
2308 else if (strcmpic(ss, US"per_addr") == 0)
2310 RATE_SET(mode, PER_RCPT);
2311 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2312 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2314 else if (strncmpic(ss, US"count=", 6) == 0)
2317 count = Ustrtod(ss+6, &e);
2318 if (count < 0.0 || *e != '\0')
2319 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2321 else if (strncmpic(ss, US"unique=", 7) == 0)
2322 unique = string_copy(ss + 7);
2324 key = string_copy(ss);
2326 key = string_sprintf("%s/%s", key, ss);
2329 /* Sanity check. When the badacl flag is set the update mode must either
2330 be readonly (which is the default if it is omitted) or, for backwards
2331 compatibility, a combination of noupdate and strict or leaky. */
2333 if (mode == RATE_PER_CLASH)
2334 return ratelimit_error(log_msgptr, "conflicting per_* options");
2335 if (leaky + strict + readonly > 1)
2336 return ratelimit_error(log_msgptr, "conflicting update modes");
2337 if (badacl && (leaky || strict) && !noupdate)
2338 return ratelimit_error(log_msgptr,
2339 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2340 ratelimit_option_string[mode], acl_wherenames[where]);
2342 /* Set the default values of any unset options. In readonly mode we
2343 perform the rate computation without any increment so that its value
2344 decays to eventually allow over-limit senders through. */
2346 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2347 if (badacl) readonly = TRUE;
2348 if (readonly) count = 0.0;
2349 if (!strict && !readonly) leaky = TRUE;
2350 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2352 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2353 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2354 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2355 are added to the key because they alter the meaning of the stored data. */
2358 key = !sender_host_address ? US"" : sender_host_address;
2360 key = string_sprintf("%s/%s/%s%s",
2362 ratelimit_option_string[mode],
2363 unique == NULL ? "" : "unique/",
2367 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2369 /* See if we have already computed the rate by looking in the relevant tree.
2370 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2371 pool so that they survive across resets. In readonly mode we only remember the
2372 result for the rest of this command in case a later command changes it. After
2373 this bit of logic the code is independent of the per_* mode. */
2375 old_pool = store_pool;
2378 anchor = &ratelimiters_cmd;
2382 anchor = &ratelimiters_conn;
2383 store_pool = POOL_PERM;
2387 case RATE_PER_ALLRCPTS:
2388 anchor = &ratelimiters_mail;
2393 anchor = &ratelimiters_cmd;
2396 anchor = NULL; /* silence an "unused" complaint */
2397 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2398 "internal ACL error: unknown ratelimit mode %d", mode);
2402 if ((t = tree_search(*anchor, key)))
2405 /* The following few lines duplicate some of the code below. */
2406 rc = (dbd->rate < limit)? FAIL : OK;
2407 store_pool = old_pool;
2408 sender_rate = string_sprintf("%.1f", dbd->rate);
2410 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2414 /* We aren't using a pre-computed rate, so get a previously recorded rate
2415 from the database, which will be updated and written back if required. */
2417 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE)))
2419 store_pool = old_pool;
2421 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2422 *log_msgptr = US"ratelimit database not available";
2425 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2428 gettimeofday(&tv, NULL);
2432 /* Locate the basic ratelimit block inside the DB data. */
2433 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2436 /* Forget the old Bloom filter if it is too old, so that we count each
2437 repeating event once per period. We don't simply clear and re-use the old
2438 filter because we want its size to change if the limit changes. Note that
2439 we keep the dbd pointer for copying the rate into the new data block. */
2441 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2443 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2449 if(unique && dbdb_size < sizeof(*dbdb))
2451 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2456 /* Allocate a new data block if the database lookup failed
2457 or the Bloom filter passed its age limit. */
2463 /* No Bloom filter. This basic ratelimit block is initialized below. */
2464 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2465 dbdb_size = sizeof(*dbd);
2466 dbdb = store_get(dbdb_size);
2471 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2473 /* See the long comment below for an explanation of the magic number 2.
2474 The filter has a minimum size in case the rate limit is very small;
2475 this is determined by the definition of dbdata_ratelimit_unique. */
2477 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2478 if (extra < 0) extra = 0;
2479 dbdb_size = sizeof(*dbdb) + extra;
2480 dbdb = store_get(dbdb_size);
2481 dbdb->bloom_epoch = tv.tv_sec;
2482 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2483 memset(dbdb->bloom, 0, dbdb->bloom_size);
2485 /* Preserve any basic ratelimit data (which is our longer-term memory)
2486 by copying it from the discarded block. */
2496 /* If we are counting unique events, find out if this event is new or not.
2497 If the client repeats the event during the current period then it should be
2498 counted. We skip this code in readonly mode for efficiency, because any
2499 changes to the filter will be discarded and because count is already set to
2502 if (unique && !readonly)
2504 /* We identify unique events using a Bloom filter. (You can find my
2505 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2506 With the per_addr option, an "event" is a recipient address, though the
2507 user can use the unique option to define their own events. We only count
2508 an event if we have not seen it before.
2510 We size the filter according to the rate limit, which (in leaky mode)
2511 is the limit on the population of the filter. We allow 16 bits of space
2512 per entry (see the construction code above) and we set (up to) 8 of them
2513 when inserting an element (see the loop below). The probability of a false
2514 positive (an event we have not seen before but which we fail to count) is
2518 allzero = exp(-numhash * pop / size)
2519 = exp(-0.5 * pop / limit)
2520 fpr = pow(1 - allzero, numhash)
2522 For senders at the limit the fpr is 0.06% or 1 in 1700
2523 and for senders at half the limit it is 0.0006% or 1 in 170000
2525 In strict mode the Bloom filter can fill up beyond the normal limit, in
2526 which case the false positive rate will rise. This means that the
2527 measured rate for very fast senders can bogusly drop off after a while.
2529 At twice the limit, the fpr is 2.5% or 1 in 40
2530 At four times the limit, it is 31% or 1 in 3.2
2532 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2533 decay below the limit, and if this is more than one then the Bloom filter
2534 will be discarded before the decay gets that far. The false positive rate
2535 at this threshold is 9.3% or 1 in 10.7. */
2538 unsigned n, hash, hinc;
2542 /* Instead of using eight independent hash values, we combine two values
2543 using the formula h1 + n * h2. This does not harm the Bloom filter's
2544 performance, and means the amount of hash we need is independent of the
2545 number of bits we set in the filter. */
2547 md5_start(&md5info);
2548 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2549 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2550 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2552 /* Scan the bits corresponding to this event. A zero bit means we have
2553 not seen it before. Ensure all bits are set to record this event. */
2555 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2558 for (n = 0; n < 8; n++, hash += hinc)
2560 int bit = 1 << (hash % 8);
2561 int byte = (hash / 8) % dbdb->bloom_size;
2562 if ((dbdb->bloom[byte] & bit) == 0)
2564 dbdb->bloom[byte] |= bit;
2569 /* If this event has occurred before, do not count it. */
2573 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2577 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2580 /* If there was no previous ratelimit data block for this key, initialize
2581 the new one, otherwise update the block from the database. The initial rate
2582 is what would be computed by the code below for an infinite interval. */
2586 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2588 dbd->time_stamp = tv.tv_sec;
2589 dbd->time_usec = tv.tv_usec;
2594 /* The smoothed rate is computed using an exponentially weighted moving
2595 average adjusted for variable sampling intervals. The standard EWMA for
2596 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2597 where f() is the measured value and f'() is the smoothed value.
2599 Old data decays out of the smoothed value exponentially, such that data n
2600 samples old is multiplied by a^n. The exponential decay time constant p
2601 is defined such that data p samples old is multiplied by 1/e, which means
2602 that a = exp(-1/p). We can maintain the same time constant for a variable
2603 sampling interval i by using a = exp(-i/p).
2605 The rate we are measuring is messages per period, suitable for directly
2606 comparing with the limit. The average rate between now and the previous
2607 message is period / interval, which we feed into the EWMA as the sample.
2609 It turns out that the number of messages required for the smoothed rate
2610 to reach the limit when they are sent in a burst is equal to the limit.
2611 This can be seen by analysing the value of the smoothed rate after N
2612 messages sent at even intervals. Let k = (1 - a) * p/i
2614 rate_1 = (1 - a) * p/i + a * rate_0
2616 rate_2 = k + a * rate_1
2617 = k + a * k + a^2 * rate_0
2618 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2619 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2620 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2621 = rate_0 * a^N + p/i * (1 - a^N)
2623 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2625 rate_N = p/i + (rate_0 - p/i) * a^N
2626 a^N = (rate_N - p/i) / (rate_0 - p/i)
2627 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2628 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2630 Numerical analysis of the above equation, setting the computed rate to
2631 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2632 rates, p/i, the number of messages N = limit. So limit serves as both the
2633 maximum rate measured in messages per period, and the maximum number of
2634 messages that can be sent in a fast burst. */
2636 double this_time = (double)tv.tv_sec
2637 + (double)tv.tv_usec / 1000000.0;
2638 double prev_time = (double)dbd->time_stamp
2639 + (double)dbd->time_usec / 1000000.0;
2641 /* We must avoid division by zero, and deal gracefully with the clock going
2642 backwards. If we blunder ahead when time is in reverse then the computed
2643 rate will be bogus. To be safe we clamp interval to a very small number. */
2645 double interval = this_time - prev_time <= 0.0 ? 1e-9
2646 : this_time - prev_time;
2648 double i_over_p = interval / period;
2649 double a = exp(-i_over_p);
2651 /* Combine the instantaneous rate (period / interval) with the previous rate
2652 using the smoothing factor a. In order to measure sized events, multiply the
2653 instantaneous rate by the count of bytes or recipients etc. */
2655 dbd->time_stamp = tv.tv_sec;
2656 dbd->time_usec = tv.tv_usec;
2657 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2659 /* When events are very widely spaced the computed rate tends towards zero.
2660 Although this is accurate it turns out not to be useful for our purposes,
2661 especially when the first event after a long silence is the start of a spam
2662 run. A more useful model is that the rate for an isolated event should be the
2663 size of the event per the period size, ignoring the lack of events outside
2664 the current period and regardless of where the event falls in the period. So,
2665 if the interval was so long that the calculated rate is unhelpfully small, we
2666 re-initialize the rate. In the absence of higher-rate bursts, the condition
2667 below is true if the interval is greater than the period. */
2669 if (dbd->rate < count) dbd->rate = count;
2672 /* Clients sending at the limit are considered to be over the limit.
2673 This matters for edge cases such as a limit of zero, when the client
2674 should be completely blocked. */
2676 rc = dbd->rate < limit ? FAIL : OK;
2678 /* Update the state if the rate is low or if we are being strict. If we
2679 are in leaky mode and the sender's rate is too high, we do not update
2680 the recorded rate in order to avoid an over-aggressive sender's retry
2681 rate preventing them from getting any email through. If readonly is set,
2682 neither leaky nor strict are set, so we do not do any updates. */
2684 if ((rc == FAIL && leaky) || strict)
2686 dbfn_write(dbm, key, dbdb, dbdb_size);
2687 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2691 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2692 readonly? "readonly mode" : "over the limit, but leaky");
2697 /* Store the result in the tree for future reference. */
2699 t = store_get(sizeof(tree_node) + Ustrlen(key));
2701 Ustrcpy(t->name, key);
2702 (void)tree_insertnode(anchor, t);
2704 /* We create the formatted version of the sender's rate very late in
2705 order to ensure that it is done using the correct storage pool. */
2707 store_pool = old_pool;
2708 sender_rate = string_sprintf("%.1f", dbd->rate);
2711 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2718 /*************************************************
2719 * The udpsend ACL modifier *
2720 *************************************************/
2722 /* Called by acl_check_condition() below.
2725 arg the option string for udpsend=
2726 log_msgptr for error messages
2728 Returns: OK - Completed.
2729 DEFER - Problem with DNS lookup.
2730 ERROR - Syntax error in options.
2734 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2746 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2747 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2751 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2756 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2761 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2764 portnum = Ustrtol(portstr, &portend, 10);
2765 if (*portend != '\0')
2767 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2771 /* Make a single-item host list. */
2772 h = store_get(sizeof(host_item));
2773 memset(h, 0, sizeof(host_item));
2778 if (string_is_ip_address(hostname, NULL))
2779 h->address = hostname, r = HOST_FOUND;
2781 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2782 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2784 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2789 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2791 /*XXX this could better use sendto */
2792 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2793 1, NULL, &errstr, NULL);
2794 if (r < 0) goto defer;
2796 r = send(s, arg, len, 0);
2799 errstr = US strerror(errno);
2807 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2812 debug_printf_indent("udpsend %d bytes\n", r);
2817 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2823 /*************************************************
2824 * Handle conditions/modifiers on an ACL item *
2825 *************************************************/
2827 /* Called from acl_check() below.
2831 cb ACL condition block - if NULL, result is OK
2832 where where called from
2833 addr the address being checked for RCPT, or NULL
2834 level the nesting level
2835 epp pointer to pass back TRUE if "endpass" encountered
2836 (applies only to "accept" and "discard")
2837 user_msgptr user message pointer
2838 log_msgptr log message pointer
2839 basic_errno pointer to where to put verify error
2841 Returns: OK - all conditions are met
2842 DISCARD - an "acl" condition returned DISCARD - only allowed
2843 for "accept" or "discard" verbs
2844 FAIL - at least one condition fails
2845 FAIL_DROP - an "acl" condition returned FAIL_DROP
2846 DEFER - can't tell at the moment (typically, lookup defer,
2847 but can be temporary callout problem)
2848 ERROR - ERROR from nested ACL or expansion failure or other
2853 acl_check_condition(int verb, acl_condition_block *cb, int where,
2854 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2855 uschar **log_msgptr, int *basic_errno)
2857 uschar *user_message = NULL;
2858 uschar *log_message = NULL;
2860 #ifdef WITH_CONTENT_SCAN
2864 for (; cb; cb = cb->next)
2869 /* The message and log_message items set up messages to be used in
2870 case of rejection. They are expanded later. */
2872 if (cb->type == ACLC_MESSAGE)
2874 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2875 user_message = cb->arg;
2879 if (cb->type == ACLC_LOG_MESSAGE)
2881 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2882 log_message = cb->arg;
2886 /* The endpass "condition" just sets a flag to show it occurred. This is
2887 checked at compile time to be on an "accept" or "discard" item. */
2889 if (cb->type == ACLC_ENDPASS)
2895 /* For other conditions and modifiers, the argument is expanded now for some
2896 of them, but not for all, because expansion happens down in some lower level
2897 checking functions in some cases. */
2899 if (!conditions[cb->type].expand_at_top)
2901 else if (!(arg = expand_string(cb->arg)))
2903 if (f.expand_string_forcedfail) continue;
2904 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2905 cb->arg, expand_string_message);
2906 return f.search_find_defer ? DEFER : ERROR;
2909 /* Show condition, and expanded condition if it's different */
2914 debug_printf_indent("check %s%s %n",
2915 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2916 conditions[cb->type].name, &lhswidth);
2918 if (cb->type == ACLC_SET)
2920 #ifndef DISABLE_DKIM
2921 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2922 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2924 debug_printf("%s ", cb->u.varname);
2930 debug_printf("acl_%s ", cb->u.varname);
2931 lhswidth += 5 + Ustrlen(cb->u.varname);
2935 debug_printf("= %s\n", cb->arg);
2938 debug_printf("%.*s= %s\n", lhswidth,
2942 /* Check that this condition makes sense at this time */
2944 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2946 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2947 conditions[cb->type].is_modifier ? "use" : "test",
2948 conditions[cb->type].name, acl_wherenames[where]);
2952 /* Run the appropriate test for each condition, or take the appropriate
2953 action for the remaining modifiers. */
2957 case ACLC_ADD_HEADER:
2961 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2965 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2966 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2968 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2969 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2975 case ACLC_AUTHENTICATED:
2976 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
2977 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
2980 #ifdef EXPERIMENTAL_BRIGHTMAIL
2981 case ACLC_BMI_OPTIN:
2983 int old_pool = store_pool;
2984 store_pool = POOL_PERM;
2985 bmi_current_optin = string_copy(arg);
2986 store_pool = old_pool;
2991 case ACLC_CONDITION:
2992 /* The true/false parsing here should be kept in sync with that used in
2993 expand.c when dealing with ECOND_BOOL so that we don't have too many
2994 different definitions of what can be a boolean. */
2996 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
2997 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2998 rc = (Uatoi(arg) == 0)? FAIL : OK;
3000 rc = (strcmpic(arg, US"no") == 0 ||
3001 strcmpic(arg, US"false") == 0)? FAIL :
3002 (strcmpic(arg, US"yes") == 0 ||
3003 strcmpic(arg, US"true") == 0)? OK : DEFER;
3005 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3008 case ACLC_CONTINUE: /* Always succeeds */
3013 const uschar *p = NULL;
3014 control_type = decode_control(arg, &p, where, log_msgptr);
3016 /* Check if this control makes sense at this time */
3018 if (controls_list[control_type].forbids & (1 << where))
3020 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3021 controls_list[control_type].name, acl_wherenames[where]);
3025 switch(control_type)
3027 case CONTROL_AUTH_UNADVERTISED:
3028 f.allow_auth_unadvertised = TRUE;
3031 #ifdef EXPERIMENTAL_BRIGHTMAIL
3032 case CONTROL_BMI_RUN:
3037 #ifndef DISABLE_DKIM
3038 case CONTROL_DKIM_VERIFY:
3039 f.dkim_disable_verify = TRUE;
3040 #ifdef EXPERIMENTAL_DMARC
3041 /* Since DKIM was blocked, skip DMARC too */
3042 f.dmarc_disable_verify = TRUE;
3043 f.dmarc_enable_forensic = FALSE;
3048 #ifdef EXPERIMENTAL_DMARC
3049 case CONTROL_DMARC_VERIFY:
3050 f.dmarc_disable_verify = TRUE;
3053 case CONTROL_DMARC_FORENSIC:
3054 f.dmarc_enable_forensic = TRUE;
3061 int fd, af, level, optname, value;
3062 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3063 a socket; we can accept that, we'll just debug-log failures anyway. */
3064 fd = fileno(smtp_in);
3065 af = ip_get_address_family(fd);
3069 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3073 if (dscp_lookup(p+1, af, &level, &optname, &value))
3075 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3077 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3078 p+1, strerror(errno));
3082 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3087 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3093 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3101 case CONTROL_CASEFUL_LOCAL_PART:
3102 deliver_localpart = addr->cc_local_part;
3105 case CONTROL_CASELOWER_LOCAL_PART:
3106 deliver_localpart = addr->lc_local_part;
3109 case CONTROL_ENFORCE_SYNC:
3110 smtp_enforce_sync = TRUE;
3113 case CONTROL_NO_ENFORCE_SYNC:
3114 smtp_enforce_sync = FALSE;
3117 #ifdef WITH_CONTENT_SCAN
3118 case CONTROL_NO_MBOX_UNSPOOL:
3119 f.no_mbox_unspool = TRUE;
3123 case CONTROL_NO_MULTILINE:
3124 f.no_multiline_responses = TRUE;
3127 case CONTROL_NO_PIPELINING:
3128 f.pipelining_enable = FALSE;
3131 case CONTROL_NO_DELAY_FLUSH:
3132 f.disable_delay_flush = TRUE;
3135 case CONTROL_NO_CALLOUT_FLUSH:
3136 f.disable_callout_flush = TRUE;
3139 case CONTROL_FAKEREJECT:
3140 cancel_cutthrough_connection(TRUE, US"fakereject");
3141 case CONTROL_FAKEDEFER:
3142 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3145 const uschar *pp = p + 1;
3146 while (*pp != 0) pp++;
3147 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3152 /* Explicitly reset to default string */
3153 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).";
3157 case CONTROL_FREEZE:
3158 f.deliver_freeze = TRUE;
3159 deliver_frozen_at = time(NULL);
3160 freeze_tell = freeze_tell_config; /* Reset to configured value */
3161 if (Ustrncmp(p, "/no_tell", 8) == 0)
3168 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3171 cancel_cutthrough_connection(TRUE, US"item frozen");
3174 case CONTROL_QUEUE_ONLY:
3175 f.queue_only_policy = TRUE;
3176 cancel_cutthrough_connection(TRUE, US"queueing forced");
3179 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS)
3180 case CONTROL_REQUIRETLS:
3181 tls_requiretls |= REQUIRETLS_MSG;
3184 case CONTROL_SUBMISSION:
3185 originator_name = US"";
3186 f.submission_mode = TRUE;
3189 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3192 f.active_local_sender_retain = TRUE;
3193 f.active_local_from_check = FALSE;
3195 else if (Ustrncmp(p, "/domain=", 8) == 0)
3197 const uschar *pp = p + 8;
3198 while (*pp != 0 && *pp != '/') pp++;
3199 submission_domain = string_copyn(p+8, pp-p-8);
3202 /* The name= option must be last, because it swallows the rest of
3204 else if (Ustrncmp(p, "/name=", 6) == 0)
3206 const uschar *pp = p + 6;
3207 while (*pp != 0) pp++;
3208 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3209 big_buffer, big_buffer_size));
3216 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3223 uschar * debug_tag = NULL;
3224 uschar * debug_opts = NULL;
3229 const uschar * pp = p+1;
3230 if (Ustrncmp(pp, "tag=", 4) == 0)
3232 for (pp += 4; *pp && *pp != '/';) pp++;
3233 debug_tag = string_copyn(p+5, pp-p-5);
3235 else if (Ustrncmp(pp, "opts=", 5) == 0)
3237 for (pp += 5; *pp && *pp != '/';) pp++;
3238 debug_opts = string_copyn(p+6, pp-p-6);
3240 else if (Ustrncmp(pp, "kill", 4) == 0)
3242 for (pp += 4; *pp && *pp != '/';) pp++;
3246 while (*pp && *pp != '/') pp++;
3251 debug_logging_stop();
3253 debug_logging_activate(debug_tag, debug_opts);
3257 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3258 f.suppress_local_fixups = TRUE;
3261 case CONTROL_CUTTHROUGH_DELIVERY:
3263 uschar * ignored = NULL;
3264 #ifndef DISABLE_PRDR
3269 /* Too hard to think about for now. We might in future cutthrough
3270 the case where both sides handle prdr and this-node prdr acl
3272 ignored = US"PRDR active";
3275 if (f.deliver_freeze)
3276 ignored = US"frozen";
3277 else if (f.queue_only_policy)
3278 ignored = US"queue-only";
3279 else if (fake_response == FAIL)
3280 ignored = US"fakereject";
3283 if (rcpt_count == 1)
3285 cutthrough.delivery = TRUE; /* control accepted */
3288 const uschar * pp = p+1;
3289 if (Ustrncmp(pp, "defer=", 6) == 0)
3292 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3293 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3296 while (*pp && *pp != '/') pp++;
3301 ignored = US"nonfirst rcpt";
3304 DEBUG(D_acl) if (ignored)
3305 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3310 case CONTROL_UTF8_DOWNCONVERT:
3315 message_utf8_downconvert = 1;
3316 addr->prop.utf8_downcvt = TRUE;
3317 addr->prop.utf8_downcvt_maybe = FALSE;
3323 message_utf8_downconvert = 0;
3324 addr->prop.utf8_downcvt = FALSE;
3325 addr->prop.utf8_downcvt_maybe = FALSE;
3329 if (p[1] == '-' && p[2] == '1')
3331 message_utf8_downconvert = -1;
3332 addr->prop.utf8_downcvt = FALSE;
3333 addr->prop.utf8_downcvt_maybe = TRUE;
3337 *log_msgptr = US"bad option value for control=utf8_downconvert";
3341 message_utf8_downconvert = 1;
3342 addr->prop.utf8_downcvt = TRUE;
3343 addr->prop.utf8_downcvt_maybe = FALSE;
3353 #ifdef EXPERIMENTAL_DCC
3356 /* Separate the regular expression and any optional parameters. */
3357 const uschar * list = arg;
3358 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3359 /* Run the dcc backend. */
3360 rc = dcc_process(&ss);
3361 /* Modify return code based upon the existence of options. */
3362 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3363 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3364 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3369 #ifdef WITH_CONTENT_SCAN
3371 rc = mime_decode(&arg);
3377 int delay = readconf_readtime(arg, 0, FALSE);
3380 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3381 "modifier: \"%s\" is not a time value", arg);
3386 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3391 debug_printf_indent("delay skipped in -bh checking mode\n");
3394 /* NOTE 1: Remember that we may be
3395 dealing with stdin/stdout here, in addition to TCP/IP connections.
3396 Also, delays may be specified for non-SMTP input, where smtp_out and
3397 smtp_in will be NULL. Whatever is done must work in all cases.
3399 NOTE 2: The added feature of flushing the output before a delay must
3400 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3405 if (smtp_out && !f.disable_delay_flush)
3408 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3414 p.fd = fileno(smtp_out);
3415 p.events = POLLRDHUP;
3418 if (poll(&p, n, delay*1000) > 0)
3419 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3422 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3423 TCP/IP connection has gone away without reading from it. This means
3424 that we cannot shorten the delay below if the client goes away,
3425 because we cannot discover that the client has closed its end of the
3426 connection. (The connection is actually in a half-closed state,
3427 waiting for the server to close its end.) It would be nice to be able
3428 to detect this state, so that the Exim process is not held up
3429 unnecessarily. However, it seems that we can't. The poll() function
3430 does not do the right thing, and in any case it is not always
3433 while (delay > 0) delay = sleep(delay);
3440 #ifndef DISABLE_DKIM
3441 case ACLC_DKIM_SIGNER:
3442 if (dkim_cur_signer)
3443 rc = match_isinlist(dkim_cur_signer,
3444 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3449 case ACLC_DKIM_STATUS:
3450 rc = match_isinlist(dkim_verify_status,
3451 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3455 #ifdef EXPERIMENTAL_DMARC
3456 case ACLC_DMARC_STATUS:
3457 if (!f.dmarc_has_been_checked)
3459 f.dmarc_has_been_checked = TRUE;
3460 /* used long way of dmarc_exim_expand_query() in case we need more
3461 * view into the process in the future. */
3462 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3463 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3468 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3472 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3473 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3476 /* The value in tls_cipher is the full cipher name, for example,
3477 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3478 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3479 what may in practice come out of the SSL library - which at the time of
3480 writing is poorly documented. */
3482 case ACLC_ENCRYPTED:
3483 if (tls_in.cipher == NULL) rc = FAIL; else
3485 uschar *endcipher = NULL;
3486 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3487 if (cipher == NULL) cipher = tls_in.cipher; else
3489 endcipher = Ustrchr(++cipher, ':');
3490 if (endcipher != NULL) *endcipher = 0;
3492 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3493 if (endcipher != NULL) *endcipher = ':';
3497 /* Use verify_check_this_host() instead of verify_check_host() so that
3498 we can pass over &host_data to catch any looked up data. Once it has been
3499 set, it retains its value so that it's still there if another ACL verb
3500 comes through here and uses the cache. However, we must put it into
3501 permanent store in case it is also expected to be used in a subsequent
3502 message in the same SMTP connection. */
3505 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3506 (sender_host_address == NULL)? US"" : sender_host_address,
3508 if (rc == DEFER) *log_msgptr = search_error_message;
3509 if (host_data) host_data = string_copy_malloc(host_data);
3512 case ACLC_LOCAL_PARTS:
3513 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3514 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3515 CUSS &deliver_localpart_data);
3518 case ACLC_LOG_REJECT_TARGET:
3522 const uschar *s = arg;
3524 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3526 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3527 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3528 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3531 logbits |= LOG_MAIN|LOG_REJECT;
3532 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3533 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3536 log_reject_target = logbits;
3543 const uschar *s = arg;
3549 if (Ustrncmp(s, "main", 4) == 0)
3550 { logbits |= LOG_MAIN; s += 4; }
3551 else if (Ustrncmp(s, "panic", 5) == 0)
3552 { logbits |= LOG_PANIC; s += 5; }
3553 else if (Ustrncmp(s, "reject", 6) == 0)
3554 { logbits |= LOG_REJECT; s += 6; }
3557 logbits = LOG_MAIN|LOG_PANIC;
3558 s = string_sprintf(":unknown log name in \"%s\" in "
3559 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3565 while (isspace(*s)) s++;
3567 if (logbits == 0) logbits = LOG_MAIN;
3568 log_write(0, logbits, "%s", string_printing(s));
3572 #ifdef WITH_CONTENT_SCAN
3573 case ACLC_MALWARE: /* Run the malware backend. */
3575 /* Separate the regular expression and any optional parameters. */
3576 const uschar * list = arg;
3577 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3579 BOOL defer_ok = FALSE;
3582 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3583 if (strcmpic(opt, US"defer_ok") == 0)
3585 else if ( strncmpic(opt, US"tmo=", 4) == 0
3586 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3589 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3593 rc = malware(ss, timeout);
3594 if (rc == DEFER && defer_ok)
3595 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3599 case ACLC_MIME_REGEX:
3600 rc = mime_regex(&arg);
3605 if (Ustrchr(arg, '/'))
3607 *log_msgptr = string_sprintf(
3608 "Directory separator not permitted in queue name: '%s'", arg);
3611 queue_name = string_copy_malloc(arg);
3614 case ACLC_RATELIMIT:
3615 rc = acl_ratelimit(arg, where, log_msgptr);
3618 case ACLC_RECIPIENTS:
3619 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3620 CUSS &recipient_data);
3623 #ifdef WITH_CONTENT_SCAN
3629 case ACLC_REMOVE_HEADER:
3630 setup_remove_header(arg);
3633 case ACLC_SENDER_DOMAINS:
3636 sdomain = Ustrrchr(sender_address, '@');
3637 sdomain = sdomain ? sdomain + 1 : US"";
3638 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3639 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3644 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3645 sender_address_cache, -1, 0, CUSS &sender_data);
3648 /* Connection variables must persist forever */
3652 int old_pool = store_pool;
3653 if ( cb->u.varname[0] == 'c'
3654 #ifndef DISABLE_DKIM
3655 || cb->u.varname[0] == 'd'
3657 #ifndef DISABLE_EVENT
3658 || event_name /* An event is being delivered */
3661 store_pool = POOL_PERM;
3662 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3663 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3664 dkim_verify_status = string_copy(arg);
3665 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3666 dkim_verify_reason = string_copy(arg);
3669 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3670 store_pool = old_pool;
3674 #ifdef WITH_CONTENT_SCAN
3677 /* Separate the regular expression and any optional parameters. */
3678 const uschar * list = arg;
3679 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3681 rc = spam(CUSS &ss);
3682 /* Modify return code based upon the existence of options. */
3683 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3684 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3685 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3692 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3694 case ACLC_SPF_GUESS:
3695 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3700 rc = acl_udpsend(arg, log_msgptr);
3703 /* If the verb is WARN, discard any user message from verification, because
3704 such messages are SMTP responses, not header additions. The latter come
3705 only from explicit "message" modifiers. However, put the user message into
3706 $acl_verify_message so it can be used in subsequent conditions or modifiers
3707 (until something changes it). */
3710 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3712 acl_verify_message = *user_msgptr;
3713 if (verb == ACL_WARN) *user_msgptr = NULL;
3717 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3718 "condition %d", cb->type);
3722 /* If a condition was negated, invert OK/FAIL. */
3724 if (!conditions[cb->type].is_modifier && cb->u.negated)
3725 if (rc == OK) rc = FAIL;
3726 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3728 if (rc != OK) break; /* Conditions loop */
3732 /* If the result is the one for which "message" and/or "log_message" are used,
3733 handle the values of these modifiers. If there isn't a log message set, we make
3734 it the same as the user message.
3736 "message" is a user message that will be included in an SMTP response. Unless
3737 it is empty, it overrides any previously set user message.
3739 "log_message" is a non-user message, and it adds to any existing non-user
3740 message that is already set.
3742 Most verbs have but a single return for which the messages are relevant, but
3743 for "discard", it's useful to have the log message both when it succeeds and
3744 when it fails. For "accept", the message is used in the OK case if there is no
3745 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3748 if (*epp && rc == OK) user_message = NULL;
3750 if ((BIT(rc) & msgcond[verb]) != 0)
3753 uschar *old_user_msgptr = *user_msgptr;
3754 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3756 /* If the verb is "warn", messages generated by conditions (verification or
3757 nested ACLs) are always discarded. This also happens for acceptance verbs
3758 when they actually do accept. Only messages specified at this level are used.
3759 However, the value of an existing message is available in $acl_verify_message
3760 during expansions. */
3762 if (verb == ACL_WARN ||
3763 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3764 *log_msgptr = *user_msgptr = NULL;
3768 acl_verify_message = old_user_msgptr;
3769 expmessage = expand_string(user_message);
3772 if (!f.expand_string_forcedfail)
3773 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3774 user_message, expand_string_message);
3776 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3781 acl_verify_message = old_log_msgptr;
3782 expmessage = expand_string(log_message);
3785 if (!f.expand_string_forcedfail)
3786 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3787 log_message, expand_string_message);
3789 else if (expmessage[0] != 0)
3791 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3792 string_sprintf("%s: %s", expmessage, *log_msgptr);
3796 /* If no log message, default it to the user message */
3798 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3801 acl_verify_message = NULL;
3809 /*************************************************
3810 * Get line from a literal ACL *
3811 *************************************************/
3813 /* This function is passed to acl_read() in order to extract individual lines
3814 of a literal ACL, which we access via static pointers. We can destroy the
3815 contents because this is called only once (the compiled ACL is remembered).
3817 This code is intended to treat the data in the same way as lines in the main
3818 Exim configuration file. That is:
3820 . Leading spaces are ignored.
3822 . A \ at the end of a line is a continuation - trailing spaces after the \
3823 are permitted (this is because I don't believe in making invisible things
3824 significant). Leading spaces on the continued part of a line are ignored.
3826 . Physical lines starting (significantly) with # are totally ignored, and
3827 may appear within a sequence of backslash-continued lines.
3829 . Blank lines are ignored, but will end a sequence of continuations.
3832 Returns: a pointer to the next line
3836 static uschar *acl_text; /* Current pointer in the text */
3837 static uschar *acl_text_end; /* Points one past the terminating '0' */
3845 /* This loop handles leading blank lines and comments. */
3849 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3850 if (*acl_text == 0) return NULL; /* No more data */
3851 yield = acl_text; /* Potential data line */
3853 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3855 /* If we hit the end before a newline, we have the whole logical line. If
3856 it's a comment, there's no more data to be given. Otherwise, yield it. */
3858 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3860 /* After reaching a newline, end this loop if the physical line does not
3861 start with '#'. If it does, it's a comment, and the loop continues. */
3863 if (*yield != '#') break;
3866 /* This loop handles continuations. We know we have some real data, ending in
3867 newline. See if there is a continuation marker at the end (ignoring trailing
3868 white space). We know that *yield is not white space, so no need to test for
3869 cont > yield in the backwards scanning loop. */
3874 for (cont = acl_text - 1; isspace(*cont); cont--);
3876 /* If no continuation follows, we are done. Mark the end of the line and
3885 /* We have encountered a continuation. Skip over whitespace at the start of
3886 the next line, and indeed the whole of the next line or lines if they are
3891 while (*(++acl_text) == ' ' || *acl_text == '\t');
3892 if (*acl_text != '#') break;
3893 while (*(++acl_text) != 0 && *acl_text != '\n');
3896 /* We have the start of a continuation line. Move all the rest of the data
3897 to join onto the previous line, and then find its end. If the end is not a
3898 newline, we are done. Otherwise loop to look for another continuation. */
3900 memmove(cont, acl_text, acl_text_end - acl_text);
3901 acl_text_end -= acl_text - cont;
3903 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3904 if (*acl_text == 0) return yield;
3907 /* Control does not reach here */
3914 /*************************************************
3915 * Check access using an ACL *
3916 *************************************************/
3918 /* This function is called from address_check. It may recurse via
3919 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3920 passed as a string which is expanded. A forced failure implies no access check
3921 is required. If the result is a single word, it is taken as the name of an ACL
3922 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3923 text, complete with newlines, and parsed as such. In both cases, the ACL check
3924 is then run. This function uses an auxiliary function for acl_read() to call
3925 for reading individual lines of a literal ACL. This is acl_getline(), which
3926 appears immediately above.
3929 where where called from
3930 addr address item when called from RCPT; otherwise NULL
3931 s the input string; NULL is the same as an empty ACL => DENY
3932 user_msgptr where to put a user error (for SMTP response)
3933 log_msgptr where to put a logging message (not for SMTP response)
3935 Returns: OK access is granted
3936 DISCARD access is apparently granted...
3937 FAIL access is denied
3938 FAIL_DROP access is denied; drop the connection
3939 DEFER can't tell at the moment
3944 acl_check_internal(int where, address_item *addr, uschar *s,
3945 uschar **user_msgptr, uschar **log_msgptr)
3948 acl_block *acl = NULL;
3949 uschar *acl_name = US"inline ACL";
3952 /* Catch configuration loops */
3956 *log_msgptr = US"ACL nested too deep: possible loop";
3962 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3966 /* At top level, we expand the incoming string. At lower levels, it has already
3967 been expanded as part of condition processing. */
3971 if (!(ss = expand_string(s)))
3973 if (f.expand_string_forcedfail) return OK;
3974 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3975 expand_string_message);
3981 while (isspace(*ss)) ss++;
3983 /* If we can't find a named ACL, the default is to parse it as an inline one.
3984 (Unless it begins with a slash; non-existent files give rise to an error.) */
3988 /* Handle the case of a string that does not contain any spaces. Look for a
3989 named ACL among those read from the configuration, or a previously read file.
3990 It is possible that the pointer to the ACL is NULL if the configuration
3991 contains a name with no data. If not found, and the text begins with '/',
3992 read an ACL from a file, and save it so it can be re-used. */
3994 if (Ustrchr(ss, ' ') == NULL)
3996 tree_node *t = tree_search(acl_anchor, ss);
3999 acl = (acl_block *)(t->data.ptr);
4002 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
4005 acl_name = string_sprintf("ACL \"%s\"", ss);
4006 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4009 else if (*ss == '/')
4011 struct stat statbuf;
4012 fd = Uopen(ss, O_RDONLY, 0);
4015 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4020 if (fstat(fd, &statbuf) != 0)
4022 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4027 acl_text = store_get(statbuf.st_size + 1);
4028 acl_text_end = acl_text + statbuf.st_size + 1;
4030 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4032 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4033 ss, strerror(errno));
4036 acl_text[statbuf.st_size] = 0;
4039 acl_name = string_sprintf("ACL \"%s\"", ss);
4040 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4044 /* Parse an ACL that is still in text form. If it came from a file, remember it
4045 in the ACL tree, having read it into the POOL_PERM store pool so that it
4046 persists between multiple messages. */
4050 int old_pool = store_pool;
4051 if (fd >= 0) store_pool = POOL_PERM;
4052 acl = acl_read(acl_getline, log_msgptr);
4053 store_pool = old_pool;
4054 if (acl == NULL && *log_msgptr != NULL) return ERROR;
4057 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
4058 Ustrcpy(t->name, ss);
4060 (void)tree_insertnode(&acl_anchor, t);
4064 /* Now we have an ACL to use. It's possible it may be NULL. */
4069 int basic_errno = 0;
4070 BOOL endpass_seen = FALSE;
4071 BOOL acl_quit_check = acl_level == 0
4072 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4074 *log_msgptr = *user_msgptr = NULL;
4075 f.acl_temp_details = FALSE;
4077 HDEBUG(D_acl) debug_printf_indent("processing \"%s\"\n", verbs[acl->verb]);
4079 /* Clear out any search error message from a previous check before testing
4082 search_error_message = NULL;
4083 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4084 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4086 /* Handle special returns: DEFER causes a return except on a WARN verb;
4087 ERROR always causes a return. */
4092 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
4093 if (basic_errno != ERRNO_CALLOUTDEFER)
4095 if (search_error_message != NULL && *search_error_message != 0)
4096 *log_msgptr = search_error_message;
4097 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4100 f.acl_temp_details = TRUE;
4101 if (acl->verb != ACL_WARN) return DEFER;
4104 default: /* Paranoia */
4106 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
4110 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4111 verbs[acl->verb], acl_name);
4115 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
4118 /* DISCARD and DROP can happen only from a nested ACL condition, and
4119 DISCARD can happen only for an "accept" or "discard" verb. */
4122 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4123 verbs[acl->verb], acl_name);
4127 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4128 verbs[acl->verb], acl_name);
4132 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4133 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4134 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4139 if (cond == OK || cond == DISCARD)
4141 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4146 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4154 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4155 if (acl_quit_check) goto badquit;
4156 f.acl_temp_details = TRUE;
4164 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4165 if (acl_quit_check) goto badquit;
4171 if (cond == OK || cond == DISCARD)
4173 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4174 if (acl_quit_check) goto badquit;
4179 HDEBUG(D_acl) debug_printf_indent("discard: endpass encountered - denying access\n");
4187 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4188 if (acl_quit_check) goto badquit;
4196 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4197 if (acl_quit_check) goto badquit;
4204 acl_warn(where, *user_msgptr, *log_msgptr);
4205 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4206 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4207 "condition test deferred%s%s", host_and_ident(TRUE),
4208 (*log_msgptr == NULL)? US"" : US": ",
4209 (*log_msgptr == NULL)? US"" : *log_msgptr);
4210 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4214 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4219 /* Pass to the next ACL item */
4224 /* We have reached the end of the ACL. This is an implicit DENY. */
4226 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4230 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4231 "('%s' verb used incorrectly)", verbs[acl->verb]);
4238 /* Same args as acl_check_internal() above, but the string s is
4239 the name of an ACL followed optionally by up to 9 space-separated arguments.
4240 The name and args are separately expanded. Args go into $acl_arg globals. */
4242 acl_check_wargs(int where, address_item *addr, const uschar *s,
4243 uschar **user_msgptr, uschar **log_msgptr)
4246 uschar * tmp_arg[9]; /* must match acl_arg[] */
4247 uschar * sav_arg[9]; /* must match acl_arg[] */
4253 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4256 for (i = 0; i < 9; i++)
4258 while (*s && isspace(*s)) s++;
4260 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4267 sav_narg = acl_narg;
4269 for (i = 0; i < acl_narg; i++)
4271 sav_arg[i] = acl_arg[i];
4272 acl_arg[i] = tmp_arg[i];
4276 sav_arg[i] = acl_arg[i];
4277 acl_arg[i++] = NULL;
4281 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4284 acl_narg = sav_narg;
4285 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4289 if (f.expand_string_forcedfail) return ERROR;
4290 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4291 tmp, expand_string_message);
4292 return f.search_find_defer ? DEFER : ERROR;
4297 /*************************************************
4298 * Check access using an ACL *
4299 *************************************************/
4301 /* Alternate interface for ACL, used by expansions */
4303 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4306 address_item *addr = NULL;
4309 *user_msgptr = *log_msgptr = NULL;
4310 sender_verified_failed = NULL;
4311 ratelimiters_cmd = NULL;
4312 log_reject_target = LOG_MAIN|LOG_REJECT;
4314 if (where == ACL_WHERE_RCPT)
4316 adb = address_defaults;
4318 addr->address = expand_string(US"$local_part@$domain");
4319 addr->domain = deliver_domain;
4320 addr->local_part = deliver_localpart;
4321 addr->cc_local_part = deliver_localpart;
4322 addr->lc_local_part = deliver_localpart;
4326 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4333 /* This is the external interface for ACL checks. It sets up an address and the
4334 expansions for $domain and $local_part when called after RCPT, then calls
4335 acl_check_internal() to do the actual work.
4338 where ACL_WHERE_xxxx indicating where called from
4339 recipient RCPT address for RCPT check, else NULL
4340 s the input string; NULL is the same as an empty ACL => DENY
4341 user_msgptr where to put a user error (for SMTP response)
4342 log_msgptr where to put a logging message (not for SMTP response)
4344 Returns: OK access is granted by an ACCEPT verb
4345 DISCARD access is granted by a DISCARD verb
4346 FAIL access is denied
4347 FAIL_DROP access is denied; drop the connection
4348 DEFER can't tell at the moment
4351 int acl_where = ACL_WHERE_UNKNOWN;
4354 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4355 uschar **log_msgptr)
4359 address_item *addr = NULL;
4361 *user_msgptr = *log_msgptr = NULL;
4362 sender_verified_failed = NULL;
4363 ratelimiters_cmd = NULL;
4364 log_reject_target = LOG_MAIN|LOG_REJECT;
4366 #ifndef DISABLE_PRDR
4367 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4369 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4372 adb = address_defaults;
4374 addr->address = recipient;
4375 if (deliver_split_address(addr) == DEFER)
4377 *log_msgptr = US"defer in percent_hack_domains check";
4381 if ((addr->prop.utf8_msg = message_smtputf8))
4383 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4384 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4387 deliver_domain = addr->domain;
4388 deliver_localpart = addr->local_part;
4393 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4395 acl_where = ACL_WHERE_UNKNOWN;
4397 /* Cutthrough - if requested,
4398 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4399 and rcpt acl returned accept,
4400 and first recipient (cancel on any subsequents)
4401 open one now and run it up to RCPT acceptance.
4402 A failed verify should cancel cutthrough request,
4403 and will pass the fail to the originator.
4404 Initial implementation: dual-write to spool.
4405 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4407 Cease cutthrough copy on rxd final dot; do not send one.
4409 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4411 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4412 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4413 If temp-reject, close the conn (and keep the spooled copy).
4414 If conn-failure, no action (and keep the spooled copy).
4418 case ACL_WHERE_RCPT:
4419 #ifndef DISABLE_PRDR
4420 case ACL_WHERE_PRDR:
4423 if (f.host_checking_callout) /* -bhc mode */
4424 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4427 && cutthrough.delivery
4428 && rcpt_count > cutthrough.nrcpt
4431 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4432 if (cutthrough.defer_pass)
4434 uschar * s = addr->message;
4435 /* Horrid kludge to recover target's SMTP message */
4437 do --s; while (!isdigit(*s));
4438 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4439 f.acl_temp_details = TRUE;
4443 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4447 else HDEBUG(D_acl) if (cutthrough.delivery)
4448 if (rcpt_count <= cutthrough.nrcpt)
4449 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4451 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4454 case ACL_WHERE_PREDATA:
4456 cutthrough_predata();
4458 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4461 case ACL_WHERE_QUIT:
4462 case ACL_WHERE_NOTQUIT:
4463 /* Drop cutthrough conns, and drop heldopen verify conns if
4464 the previous was not DATA */
4466 uschar prev = smtp_connection_had[smtp_ch_index-2];
4467 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4469 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4477 deliver_domain = deliver_localpart = deliver_address_data =
4478 deliver_domain_data = sender_address_data = NULL;
4480 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4481 ACL, which is really in the middle of an SMTP command. */
4485 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4487 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4488 "ACL", acl_wherenames[where]);
4494 /* A DROP response is not permitted from MAILAUTH */
4496 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4498 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4499 "ACL", acl_wherenames[where]);
4503 /* Before giving a response, take a look at the length of any user message, and
4504 split it up into multiple lines if possible. */
4506 *user_msgptr = string_split_message(*user_msgptr);
4507 if (fake_response != OK)
4508 fake_response_text = string_split_message(fake_response_text);
4514 /*************************************************
4515 * Create ACL variable *
4516 *************************************************/
4518 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4519 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4522 name pointer to the variable's name, starting with c or m
4524 Returns the pointer to variable's tree node
4528 acl_var_create(uschar * name)
4530 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4531 if (!(node = tree_search(*root, name)))
4533 node = store_get(sizeof(tree_node) + Ustrlen(name));
4534 Ustrcpy(node->name, name);
4535 (void)tree_insertnode(root, node);
4537 node->data.ptr = NULL;
4543 /*************************************************
4544 * Write an ACL variable in spool format *
4545 *************************************************/
4547 /* This function is used as a callback for tree_walk when writing variables to
4548 the spool file. To retain spool file compatibility, what is written is -aclc or
4549 -aclm followed by the rest of the name and the data length, space separated,
4550 then the value itself, starting on a new line, and terminated by an additional
4551 newline. When we had only numbered ACL variables, the first line might look
4552 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4556 name of the variable
4557 value of the variable
4558 ctx FILE pointer (as a void pointer)
4564 acl_var_write(uschar *name, uschar *value, void *ctx)
4566 FILE *f = (FILE *)ctx;
4567 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);