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
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. Do not invent new modifier names that result in one name
116 being the prefix of another; the binary-search in the list will go wrong. */
118 typedef struct condition_def {
121 /* Flag to indicate the condition/modifier has a string expansion done
122 at the outer level. In the other cases, expansion already occurs in the
123 checking functions. */
124 BOOL expand_at_top:1;
128 /* Bit map vector of which conditions and modifiers are not allowed at certain
129 times. For each condition and modifier, there's a bitmap of dis-allowed times.
130 For some, it is easier to specify the negation of a small number of allowed
136 static condition_def conditions[] = {
137 [ACLC_ACL] = { US"acl", FALSE, FALSE, 0 },
139 [ACLC_ADD_HEADER] = { US"add_header", TRUE, TRUE,
141 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
142 ACL_BIT_PREDATA | ACL_BIT_DATA |
146 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
148 ACL_BIT_NOTSMTP_START),
151 [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE,
152 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
153 ACL_BIT_CONNECT | ACL_BIT_HELO,
155 #ifdef EXPERIMENTAL_BRIGHTMAIL
156 [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE,
158 ACL_BIT_CONNECT | ACL_BIT_HELO |
159 ACL_BIT_DATA | ACL_BIT_MIME |
160 # ifndef DISABLE_PRDR
163 ACL_BIT_ETRN | ACL_BIT_EXPN |
165 ACL_BIT_MAIL | ACL_BIT_STARTTLS |
166 ACL_BIT_VRFY | ACL_BIT_PREDATA |
167 ACL_BIT_NOTSMTP_START,
170 [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 },
171 [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 },
173 /* Certain types of control are always allowed, so we let it through
174 always and check in the control processing itself. */
175 [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 },
177 #ifdef EXPERIMENTAL_DCC
178 [ACLC_DCC] = { US"dcc", TRUE, FALSE,
181 # ifndef DISABLE_PRDR
187 #ifdef WITH_CONTENT_SCAN
188 [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
191 [ACLC_DELAY] = { US"delay", TRUE, TRUE, ACL_BIT_NOTQUIT },
193 [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
194 [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
197 [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DATA },
200 /* Explicit key lookups can be made in non-smtp ACLs so pass
201 always and check in the verify processing itself. */
202 [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 },
204 [ACLC_DOMAINS] = { US"domains", FALSE, FALSE,
206 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
212 [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE,
213 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
217 [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 },
219 [ACLC_HOSTS] = { US"hosts", FALSE, FALSE,
220 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
222 [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE,
224 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
231 [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 },
232 [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 },
233 [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 },
235 #ifdef WITH_CONTENT_SCAN
236 [ACLC_MALWARE] = { US"malware", TRUE, FALSE,
239 # ifndef DISABLE_PRDR
246 [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 },
247 #ifdef WITH_CONTENT_SCAN
248 [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
251 [ACLC_QUEUE] = { US"queue", TRUE, TRUE,
259 [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 },
260 [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~ACL_BIT_RCPT },
262 #ifdef WITH_CONTENT_SCAN
263 [ACLC_REGEX] = { US"regex", TRUE, FALSE,
266 # ifndef DISABLE_PRDR
274 [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE,
276 ~(ACL_BIT_MAIL|ACL_BIT_RCPT |
277 ACL_BIT_PREDATA | ACL_BIT_DATA |
281 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
282 ACL_BIT_NOTSMTP_START),
284 [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE,
285 ACL_BIT_AUTH | ACL_BIT_CONNECT |
287 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
288 ACL_BIT_ETRN | ACL_BIT_EXPN |
289 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
291 [ACLC_SENDERS] = { US"senders", FALSE, FALSE,
292 ACL_BIT_AUTH | ACL_BIT_CONNECT |
294 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
295 ACL_BIT_ETRN | ACL_BIT_EXPN |
296 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
299 [ACLC_SET] = { US"set", TRUE, TRUE, 0 },
301 #ifdef WITH_CONTENT_SCAN
302 [ACLC_SPAM] = { US"spam", TRUE, FALSE,
303 (unsigned int) ~(ACL_BIT_DATA |
304 # ifndef DISABLE_PRDR
311 [ACLC_SPF] = { US"spf", TRUE, FALSE,
312 ACL_BIT_AUTH | ACL_BIT_CONNECT |
313 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
314 ACL_BIT_ETRN | ACL_BIT_EXPN |
315 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
316 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
318 [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE,
319 ACL_BIT_AUTH | ACL_BIT_CONNECT |
320 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
321 ACL_BIT_ETRN | ACL_BIT_EXPN |
322 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
323 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
326 [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 },
328 /* Certain types of verify are always allowed, so we let it through
329 always and check in the verify function itself */
330 [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 },
335 /* Return values from decode_control(); used as index so keep in step
336 with the controls_list table that follows! */
339 CONTROL_AUTH_UNADVERTISED,
340 #ifdef EXPERIMENTAL_BRIGHTMAIL
343 CONTROL_CASEFUL_LOCAL_PART,
344 CONTROL_CASELOWER_LOCAL_PART,
345 CONTROL_CUTTHROUGH_DELIVERY,
351 CONTROL_DMARC_VERIFY,
352 CONTROL_DMARC_FORENSIC,
355 CONTROL_ENFORCE_SYNC,
356 CONTROL_ERROR, /* pseudo-value for decode errors */
361 CONTROL_NO_CALLOUT_FLUSH,
362 CONTROL_NO_DELAY_FLUSH,
363 CONTROL_NO_ENFORCE_SYNC,
364 #ifdef WITH_CONTENT_SCAN
365 CONTROL_NO_MBOX_UNSPOOL,
367 CONTROL_NO_MULTILINE,
368 CONTROL_NO_PIPELINING,
372 CONTROL_SUPPRESS_LOCAL_FIXUPS,
374 CONTROL_UTF8_DOWNCONVERT,
380 /* Structure listing various control arguments, with their characteristics.
381 For each control, there's a bitmap of dis-allowed times. For some, it is easier
382 to specify the negation of a small number of allowed times. */
384 typedef struct control_def {
386 BOOL has_option; /* Has /option(s) following */
387 unsigned forbids; /* bitmap of dis-allowed times */
390 static control_def controls_list[] = {
391 /* name has_option forbids */
392 [CONTROL_AUTH_UNADVERTISED] =
393 { US"allow_auth_unadvertised", FALSE,
395 ~(ACL_BIT_CONNECT | ACL_BIT_HELO)
397 #ifdef EXPERIMENTAL_BRIGHTMAIL
399 { US"bmi_run", FALSE, 0 },
401 [CONTROL_CASEFUL_LOCAL_PART] =
402 { US"caseful_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
403 [CONTROL_CASELOWER_LOCAL_PART] =
404 { US"caselower_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
405 [CONTROL_CUTTHROUGH_DELIVERY] =
406 { US"cutthrough_delivery", TRUE, 0 },
408 { US"debug", TRUE, 0 },
411 [CONTROL_DKIM_VERIFY] =
412 { US"dkim_disable_verify", FALSE,
413 ACL_BIT_DATA | ACL_BIT_NOTSMTP |
414 # ifndef DISABLE_PRDR
417 ACL_BIT_NOTSMTP_START
422 [CONTROL_DMARC_VERIFY] =
423 { US"dmarc_disable_verify", FALSE,
424 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
426 [CONTROL_DMARC_FORENSIC] =
427 { US"dmarc_enable_forensic", FALSE,
428 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
434 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | ACL_BIT_NOTQUIT
436 [CONTROL_ENFORCE_SYNC] =
437 { US"enforce_sync", FALSE,
438 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
441 /* Pseudo-value for decode errors */
443 { US"error", FALSE, 0 },
445 [CONTROL_FAKEDEFER] =
446 { US"fakedefer", TRUE,
448 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
449 ACL_BIT_PREDATA | ACL_BIT_DATA |
455 [CONTROL_FAKEREJECT] =
456 { US"fakereject", TRUE,
458 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
459 ACL_BIT_PREDATA | ACL_BIT_DATA |
468 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
469 ACL_BIT_PREDATA | ACL_BIT_DATA |
470 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
471 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
474 [CONTROL_NO_CALLOUT_FLUSH] =
475 { US"no_callout_flush", FALSE,
476 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
478 [CONTROL_NO_DELAY_FLUSH] =
479 { US"no_delay_flush", FALSE,
480 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
483 [CONTROL_NO_ENFORCE_SYNC] =
484 { US"no_enforce_sync", FALSE,
485 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
487 #ifdef WITH_CONTENT_SCAN
488 [CONTROL_NO_MBOX_UNSPOOL] =
489 { US"no_mbox_unspool", FALSE,
491 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
492 ACL_BIT_PREDATA | ACL_BIT_DATA |
493 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
497 [CONTROL_NO_MULTILINE] =
498 { US"no_multiline_responses", FALSE,
499 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
501 [CONTROL_NO_PIPELINING] =
502 { US"no_pipelining", FALSE,
503 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
509 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
510 ACL_BIT_PREDATA | ACL_BIT_DATA |
511 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
512 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
515 [CONTROL_SUBMISSION] =
516 { US"submission", TRUE,
518 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA)
520 [CONTROL_SUPPRESS_LOCAL_FIXUPS] =
521 { US"suppress_local_fixups", FALSE,
523 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
524 ACL_BIT_NOTSMTP_START)
527 [CONTROL_UTF8_DOWNCONVERT] =
528 { US"utf8_downconvert", TRUE, (unsigned) ~(ACL_BIT_RCPT | ACL_BIT_VRFY)
533 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
534 caches its result in a tree to avoid repeated DNS queries. The result is an
535 integer code which is used as an index into the following tables of
536 explanatory strings and verification return codes. */
538 static tree_node *csa_cache = NULL;
540 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
541 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
543 /* The acl_verify_csa() return code is translated into an acl_verify() return
544 code using the following table. It is OK unless the client is definitely not
545 authorized. This is because CSA is supposed to be optional for sending sites,
546 so recipients should not be too strict about checking it - especially because
547 DNS problems are quite likely to occur. It's possible to use $csa_status in
548 further ACL conditions to distinguish ok, unknown, and defer if required, but
549 the aim is to make the usual configuration simple. */
551 static int csa_return_code[] = {
554 [CSA_DEFER_SRV] = OK,
555 [CSA_DEFER_ADDR] = OK,
556 [CSA_FAIL_EXPLICIT] = FAIL,
557 [CSA_FAIL_DOMAIN] = FAIL,
558 [CSA_FAIL_NOADDR] = FAIL,
559 [CSA_FAIL_MISMATCH] = FAIL
562 static uschar *csa_status_string[] = {
563 [CSA_UNKNOWN] = US"unknown",
565 [CSA_DEFER_SRV] = US"defer",
566 [CSA_DEFER_ADDR] = US"defer",
567 [CSA_FAIL_EXPLICIT] = US"fail",
568 [CSA_FAIL_DOMAIN] = US"fail",
569 [CSA_FAIL_NOADDR] = US"fail",
570 [CSA_FAIL_MISMATCH] = US"fail"
573 static uschar *csa_reason_string[] = {
574 [CSA_UNKNOWN] = US"unknown",
576 [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)",
577 [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)",
578 [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)",
579 [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)",
580 [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)",
581 [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)"
584 /* Options for the ratelimit condition. Note that there are two variants of
585 the per_rcpt option, depending on the ACL that is used to measure the rate.
586 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
587 so the two variants must have the same internal representation as well as
588 the same configuration string. */
591 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
592 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
595 #define RATE_SET(var,new) \
596 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
598 static uschar *ratelimit_option_string[] = {
599 [RATE_PER_WHAT] = US"?",
600 [RATE_PER_CLASH] = US"!",
601 [RATE_PER_ADDR] = US"per_addr",
602 [RATE_PER_BYTE] = US"per_byte",
603 [RATE_PER_CMD] = US"per_cmd",
604 [RATE_PER_CONN] = US"per_conn",
605 [RATE_PER_MAIL] = US"per_mail",
606 [RATE_PER_RCPT] = US"per_rcpt",
607 [RATE_PER_ALLRCPTS] = US"per_rcpt"
610 /* Enable recursion between acl_check_internal() and acl_check_condition() */
612 static int acl_check_wargs(int, address_item *, const uschar *, uschar **,
616 /*************************************************
617 * Find control in list *
618 *************************************************/
620 /* The lists are always in order, so binary chop can be used.
623 name the control name to search for
624 ol the first entry in the control list
625 last one more than the offset of the last entry in the control list
627 Returns: index of a control entry, or -1 if not found
631 find_control(const uschar * name, control_def * ol, int last)
633 for (int first = 0; last > first; )
635 int middle = (first + last)/2;
636 uschar * s = ol[middle].name;
637 int c = Ustrncmp(name, s, Ustrlen(s));
638 if (c == 0) return middle;
639 else if (c > 0) first = middle + 1;
647 /*************************************************
648 * Pick out condition from list *
649 *************************************************/
651 /* Use a binary chop method
655 list list of conditions
658 Returns: offset in list, or -1 if not found
662 acl_checkcondition(uschar * name, condition_def * list, int end)
664 for (int start = 0; start < end; )
666 int mid = (start + end)/2;
667 int c = Ustrcmp(name, list[mid].name);
668 if (c == 0) return mid;
669 if (c < 0) end = mid;
670 else start = mid + 1;
676 /*************************************************
677 * Pick out name from list *
678 *************************************************/
680 /* Use a binary chop method
687 Returns: offset in list, or -1 if not found
691 acl_checkname(uschar *name, uschar **list, int end)
693 for (int start = 0; start < end; )
695 int mid = (start + end)/2;
696 int c = Ustrcmp(name, list[mid]);
697 if (c == 0) return mid;
698 if (c < 0) end = mid; else start = mid + 1;
705 /*************************************************
706 * Read and parse one ACL *
707 *************************************************/
709 /* This function is called both from readconf in order to parse the ACLs in the
710 configuration file, and also when an ACL is encountered dynamically (e.g. as
711 the result of an expansion). It is given a function to call in order to
712 retrieve the lines of the ACL. This function handles skipping comments and
713 blank lines (where relevant).
716 func function to get next line of ACL
717 error where to put an error message
719 Returns: pointer to ACL, or NULL
720 NULL can be legal (empty ACL); in this case error will be NULL
724 acl_read(uschar *(*func)(void), uschar **error)
726 acl_block *yield = NULL;
727 acl_block **lastp = &yield;
728 acl_block *this = NULL;
729 acl_condition_block *cond;
730 acl_condition_block **condp = NULL;
735 while ((s = (*func)()))
738 BOOL negated = FALSE;
739 uschar *saveline = s;
742 /* Conditions (but not verbs) are allowed to be negated by an initial
745 if (Uskip_whitespace(&s) == '!')
751 /* Read the name of a verb or a condition, or the start of a new ACL, which
752 can be started by a name, or by a macro definition. */
754 s = readconf_readname(name, sizeof(name), s);
755 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
757 /* If a verb is unrecognized, it may be another condition or modifier that
758 continues the previous verb. */
760 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
764 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
776 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
779 this = store_get(sizeof(acl_block), FALSE);
781 lastp = &(this->next);
783 this->condition = NULL;
785 this->srcline = config_lineno; /* for debug output */
786 this->srcfile = config_filename; /**/
787 condp = &(this->condition);
788 if (*s == 0) continue; /* No condition on this line */
794 s = readconf_readname(name, sizeof(name), s); /* Condition name */
797 /* Handle a condition or modifier. */
799 if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0)
801 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
806 /* The modifiers may not be negated */
808 if (negated && conditions[c].is_modifier)
810 *error = string_sprintf("ACL error: negation is not allowed with "
811 "\"%s\"", conditions[c].name);
815 /* ENDPASS may occur only with ACCEPT or DISCARD. */
817 if (c == ACLC_ENDPASS &&
818 this->verb != ACL_ACCEPT &&
819 this->verb != ACL_DISCARD)
821 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
822 conditions[c].name, verbs[this->verb]);
826 cond = store_get(sizeof(acl_condition_block), FALSE);
829 cond->u.negated = negated;
832 condp = &(cond->next);
834 /* The "set" modifier is different in that its argument is "name=value"
835 rather than just a value, and we can check the validity of the name, which
836 gives us a variable name to insert into the data block. The original ACL
837 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
838 extended to 20 of each type, but after that people successfully argued for
839 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
840 After that, we allow alphanumerics and underscores, but the first character
841 after c or m must be a digit or an underscore. This retains backwards
846 if ( Ustrncmp(s, "dkim_verify_status", 18) == 0
847 || Ustrncmp(s, "dkim_verify_reason", 18) == 0)
849 uschar * endptr = s+18;
851 if (isalnum(*endptr))
853 *error = string_sprintf("invalid variable name after \"set\" in ACL "
854 "modifier \"set %s\" "
855 "(only \"dkim_verify_status\" or \"dkim_verify_reason\" permitted)",
859 cond->u.varname = string_copyn(s, 18);
861 Uskip_whitespace(&s);
868 if (Ustrncmp(s, "acl_c", 5) != 0 && Ustrncmp(s, "acl_m", 5) != 0)
870 *error = string_sprintf("invalid variable name after \"set\" in ACL "
871 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
876 if (!isdigit(*endptr) && *endptr != '_')
878 *error = string_sprintf("invalid variable name after \"set\" in ACL "
879 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
884 while (*endptr && *endptr != '=' && !isspace(*endptr))
886 if (!isalnum(*endptr) && *endptr != '_')
888 *error = string_sprintf("invalid character \"%c\" in variable name "
889 "in ACL modifier \"set %s\"", *endptr, s);
895 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
897 Uskip_whitespace(&s);
900 /* For "set", we are now positioned for the data. For the others, only
901 "endpass" has no data */
903 if (c != ACLC_ENDPASS)
907 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
908 conditions[c].is_modifier ? US"modifier" : US"condition");
911 Uskip_whitespace(&s);
912 cond->arg = string_copy(s);
921 /*************************************************
922 * Set up added header line(s) *
923 *************************************************/
925 /* This function is called by the add_header modifier, and also from acl_warn()
926 to implement the now-deprecated way of adding header lines using "message" on a
927 "warn" verb. The argument is treated as a sequence of header lines which are
928 added to a chain, provided there isn't an identical one already there.
930 Argument: string of header lines
935 setup_header(const uschar *hstring)
938 int hlen = Ustrlen(hstring);
940 /* Ignore any leading newlines */
941 while (*hstring == '\n') hstring++, hlen--;
943 /* An empty string does nothing; ensure exactly one final newline. */
944 if (hlen <= 0) return;
945 if (hstring[--hlen] != '\n') /* no newline */
946 q = string_sprintf("%s\n", hstring);
947 else if (hstring[hlen-1] == '\n') /* double newline */
949 uschar * s = string_copy(hstring);
950 while(s[--hlen] == '\n')
957 /* Loop for multiple header lines, taking care about continuations */
959 for (p = q; *p; p = q)
963 int newtype = htype_add_bot;
964 header_line **hptr = &acl_added_headers;
966 /* Find next header line within the string */
970 q = Ustrchr(q, '\n'); /* we know there was a newline */
971 if (*++q != ' ' && *q != '\t') break;
974 /* If the line starts with a colon, interpret the instruction for where to
975 add it. This temporarily sets up a new type. */
979 if (strncmpic(p, US":after_received:", 16) == 0)
981 newtype = htype_add_rec;
984 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
986 newtype = htype_add_rfc;
989 else if (strncmpic(p, US":at_start:", 10) == 0)
991 newtype = htype_add_top;
994 else if (strncmpic(p, US":at_end:", 8) == 0)
996 newtype = htype_add_bot;
999 while (*p == ' ' || *p == '\t') p++;
1002 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1003 to the front of it. */
1005 for (s = p; s < q - 1; s++)
1006 if (*s == ':' || !isgraph(*s)) break;
1008 hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p);
1009 hlen = Ustrlen(hdr);
1011 /* See if this line has already been added */
1015 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1016 hptr = &(*hptr)->next;
1019 /* Add if not previously present */
1023 /* The header_line struct itself is not tainted, though it points to
1024 possibly tainted data. */
1025 header_line * h = store_get(sizeof(header_line), FALSE);
1038 /*************************************************
1039 * List the added header lines *
1040 *************************************************/
1046 for (header_line * h = acl_added_headers; h; h = h->next)
1049 if (h->text[i-1] == '\n') i--;
1050 g = string_append_listele_n(g, '\n', h->text, i);
1053 return g ? g->s : NULL;
1057 /*************************************************
1058 * Set up removed header line(s) *
1059 *************************************************/
1061 /* This function is called by the remove_header modifier. The argument is
1062 treated as a sequence of header names which are added to a colon separated
1063 list, provided there isn't an identical one already there.
1065 Argument: string of header names
1070 setup_remove_header(const uschar *hnames)
1073 acl_removed_headers = acl_removed_headers
1074 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1075 : string_copy(hnames);
1080 /*************************************************
1082 *************************************************/
1084 /* This function is called when a WARN verb's conditions are true. It adds to
1085 the message's headers, and/or writes information to the log. In each case, this
1086 only happens once (per message for headers, per connection for log).
1088 ** NOTE: The header adding action using the "message" setting is historic, and
1089 its use is now deprecated. The new add_header modifier should be used instead.
1092 where ACL_WHERE_xxxx indicating which ACL this is
1093 user_message message for adding to headers
1094 log_message message for logging, if different
1100 acl_warn(int where, uschar *user_message, uschar *log_message)
1102 if (log_message != NULL && log_message != user_message)
1105 string_item *logged;
1107 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1108 string_printing(log_message));
1110 /* If a sender verification has failed, and the log message is "sender verify
1111 failed", add the failure message. */
1113 if (sender_verified_failed != NULL &&
1114 sender_verified_failed->message != NULL &&
1115 strcmpic(log_message, US"sender verify failed") == 0)
1116 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1118 /* Search previously logged warnings. They are kept in malloc
1119 store so they can be freed at the start of a new message. */
1121 for (logged = acl_warn_logged; logged; logged = logged->next)
1122 if (Ustrcmp(logged->text, text) == 0) break;
1126 int length = Ustrlen(text) + 1;
1127 log_write(0, LOG_MAIN, "%s", text);
1128 logged = store_malloc(sizeof(string_item) + length);
1129 logged->text = US logged + sizeof(string_item);
1130 memcpy(logged->text, text, length);
1131 logged->next = acl_warn_logged;
1132 acl_warn_logged = logged;
1136 /* If there's no user message, we are done. */
1138 if (!user_message) return;
1140 /* If this isn't a message ACL, we can't do anything with a user message.
1143 if (where > ACL_WHERE_NOTSMTP)
1145 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1146 "found in a non-message (%s) ACL: cannot specify header lines here: "
1147 "message ignored", acl_wherenames[where]);
1151 /* The code for setting up header lines is now abstracted into a separate
1152 function so that it can be used for the add_header modifier as well. */
1154 setup_header(user_message);
1159 /*************************************************
1160 * Verify and check reverse DNS *
1161 *************************************************/
1163 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1164 address if this has not yet been done. The host_name_lookup() function checks
1165 that one of these names resolves to an address list that contains the client IP
1166 address, so we don't actually have to do the check here.
1169 user_msgptr pointer for user message
1170 log_msgptr pointer for log message
1172 Returns: OK verification condition succeeded
1173 FAIL verification failed
1174 DEFER there was a problem verifying
1178 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1182 user_msgptr = user_msgptr; /* stop compiler warning */
1184 /* Previous success */
1186 if (sender_host_name != NULL) return OK;
1188 /* Previous failure */
1190 if (host_lookup_failed)
1192 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1196 /* Need to do a lookup */
1199 debug_printf_indent("looking up host name to force name/address consistency check\n");
1201 if ((rc = host_name_lookup()) != OK)
1203 *log_msgptr = rc == DEFER
1204 ? US"host lookup deferred for reverse lookup check"
1205 : string_sprintf("host lookup failed for reverse lookup check%s",
1207 return rc; /* DEFER or FAIL */
1210 host_build_sender_fullhost();
1216 /*************************************************
1217 * Check client IP address matches CSA target *
1218 *************************************************/
1220 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1221 response for address records belonging to the CSA target hostname. The section
1222 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1223 If one of the addresses matches the client's IP address, then the client is
1224 authorized by CSA. If there are target IP addresses but none of them match
1225 then the client is using an unauthorized IP address. If there are no target IP
1226 addresses then the client cannot be using an authorized IP address. (This is
1227 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1230 dnsa the DNS answer block
1231 dnss a DNS scan block for us to use
1232 reset option specifying what portion to scan, as described above
1233 target the target hostname to use for matching RR names
1235 Returns: CSA_OK successfully authorized
1236 CSA_FAIL_MISMATCH addresses found but none matched
1237 CSA_FAIL_NOADDR no target addresses found
1241 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1244 int rc = CSA_FAIL_NOADDR;
1246 for (dns_record * rr = dns_next_rr(dnsa, dnss, reset);
1248 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1250 /* Check this is an address RR for the target hostname. */
1254 && rr->type != T_AAAA
1258 if (strcmpic(target, rr->name) != 0) continue;
1260 rc = CSA_FAIL_MISMATCH;
1262 /* Turn the target address RR into a list of textual IP addresses and scan
1263 the list. There may be more than one if it is an A6 RR. */
1265 for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next)
1267 /* If the client IP address matches the target IP address, it's good! */
1269 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1271 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1275 /* If we found some target addresses but none of them matched, the client is
1276 using an unauthorized IP address, otherwise the target has no authorized IP
1284 /*************************************************
1285 * Verify Client SMTP Authorization *
1286 *************************************************/
1288 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1289 to find the CSA SRV record corresponding to the domain argument, or
1290 $sender_helo_name if no argument is provided. It then checks that the
1291 client is authorized, and that its IP address corresponds to the SRV
1292 target's address by calling acl_verify_csa_address() above. The address
1293 should have been returned in the DNS response's ADDITIONAL section, but if
1294 not we perform another DNS lookup to get it.
1297 domain pointer to optional parameter following verify = csa
1299 Returns: CSA_UNKNOWN no valid CSA record found
1300 CSA_OK successfully authorized
1301 CSA_FAIL_* client is definitely not authorized
1302 CSA_DEFER_* there was a DNS problem
1306 acl_verify_csa(const uschar *domain)
1309 const uschar *found;
1310 int priority, weight, port;
1311 dns_answer * dnsa = store_get_dns_answer();
1317 /* Work out the domain we are using for the CSA lookup. The default is the
1318 client's HELO domain. If the client has not said HELO, use its IP address
1319 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1321 while (isspace(*domain) && *domain != '\0') ++domain;
1322 if (*domain == '\0') domain = sender_helo_name;
1323 if (domain == NULL) domain = sender_host_address;
1324 if (sender_host_address == NULL) return CSA_UNKNOWN;
1326 /* If we have an address literal, strip off the framing ready for turning it
1327 into a domain. The framing consists of matched square brackets possibly
1328 containing a keyword and a colon before the actual IP address. */
1330 if (domain[0] == '[')
1332 const uschar *start = Ustrchr(domain, ':');
1333 if (start == NULL) start = domain;
1334 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1337 /* Turn domains that look like bare IP addresses into domains in the reverse
1338 DNS. This code also deals with address literals and $sender_host_address. It's
1339 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1340 address literals, but it's probably the most friendly thing to do. This is an
1341 extension to CSA, so we allow it to be turned off for proper conformance. */
1343 if (string_is_ip_address(domain, NULL) != 0)
1345 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1346 domain = dns_build_reverse(domain);
1349 /* Find out if we've already done the CSA check for this domain. If we have,
1350 return the same result again. Otherwise build a new cached result structure
1351 for this domain. The name is filled in now, and the value is filled in when
1352 we return from this function. */
1354 t = tree_search(csa_cache, domain);
1355 if (t != NULL) return t->data.val;
1357 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain), is_tainted(domain));
1358 Ustrcpy(t->name, domain);
1359 (void)tree_insertnode(&csa_cache, t);
1361 /* Now we are ready to do the actual DNS lookup(s). */
1364 switch (dns_special_lookup(dnsa, domain, T_CSA, &found))
1366 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1369 return t->data.val = CSA_DEFER_SRV;
1371 /* If we found nothing, the client's authorization is unknown. */
1375 return t->data.val = CSA_UNKNOWN;
1377 /* We got something! Go on to look at the reply in more detail. */
1383 /* Scan the reply for well-formed CSA SRV records. */
1385 for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1387 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1389 const uschar * p = rr->data;
1391 /* Extract the numerical SRV fields (p is incremented) */
1393 GETSHORT(priority, p);
1394 GETSHORT(weight, p);
1398 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1400 /* Check the CSA version number */
1402 if (priority != 1) continue;
1404 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1405 found by dns_special_lookup() is a parent of the one we asked for), we check
1406 the subdomain assertions in the port field. At the moment there's only one
1407 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1408 SRV records of their own. */
1410 if (Ustrcmp(found, domain) != 0)
1411 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1413 /* This CSA SRV record refers directly to our domain, so we check the value
1414 in the weight field to work out the domain's authorization. 0 and 1 are
1415 unauthorized; 3 means the client is authorized but we can't check the IP
1416 address in order to authenticate it, so we treat it as unknown; values
1417 greater than 3 are undefined. */
1419 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1421 if (weight > 2) continue;
1423 /* Weight == 2, which means the domain is authorized. We must check that the
1424 client's IP address is listed as one of the SRV target addresses. Save the
1425 target hostname then break to scan the additional data for its addresses. */
1427 (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, p,
1428 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1430 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1435 /* If we didn't break the loop then no appropriate records were found. */
1437 if (!rr) return t->data.val = CSA_UNKNOWN;
1439 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1440 A target of "." indicates there are no valid addresses, so the client cannot
1441 be authorized. (This is an odd configuration because weight=2 target=. is
1442 equivalent to weight=1, but we check for it in order to keep load off the
1443 root name servers.) Note that dn_expand() turns "." into "". */
1445 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1447 /* Scan the additional section of the CSA SRV reply for addresses belonging
1448 to the target. If the name server didn't return any additional data (e.g.
1449 because it does not fully support SRV records), we need to do another lookup
1450 to obtain the target addresses; otherwise we have a definitive result. */
1452 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ADDITIONAL, target);
1453 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1455 /* The DNS lookup type corresponds to the IP version used by the client. */
1458 if (Ustrchr(sender_host_address, ':') != NULL)
1461 #endif /* HAVE_IPV6 */
1465 lookup_dnssec_authenticated = NULL;
1466 switch (dns_lookup(dnsa, target, type, NULL))
1468 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1471 return t->data.val = CSA_DEFER_ADDR;
1473 /* If the query succeeded, scan the addresses and return the result. */
1476 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ANSWERS, target);
1477 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1478 /* else fall through */
1480 /* If the target has no IP addresses, the client cannot have an authorized
1481 IP address. However, if the target site uses A6 records (not AAAA records)
1482 we have to do yet another lookup in order to check them. */
1486 return t->data.val = CSA_FAIL_NOADDR;
1492 /*************************************************
1493 * Handle verification (address & other) *
1494 *************************************************/
1496 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1497 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1498 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1503 unsigned where_allowed; /* bitmap */
1504 BOOL no_options; /* Never has /option(s) following */
1505 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1507 static verify_type_t verify_type_list[] = {
1508 /* name value where no-opt opt-sep */
1509 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, (unsigned)~0, FALSE, 0 },
1510 { US"certificate", VERIFY_CERT, (unsigned)~0, TRUE, 0 },
1511 { US"helo", VERIFY_HELO, (unsigned)~0, TRUE, 0 },
1512 { US"csa", VERIFY_CSA, (unsigned)~0, FALSE, 0 },
1513 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1514 { US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1515 { US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1516 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1517 |ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1519 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1520 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1521 #ifdef EXPERIMENTAL_ARC
1522 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1527 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1528 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1529 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1530 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1536 BOOL has_option; /* Has =option(s) following */
1537 BOOL timeval; /* Has a time value */
1539 static callout_opt_t callout_opt_list[] = {
1540 /* name value flag has-opt has-time */
1541 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1542 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1543 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1544 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1545 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1546 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1547 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1548 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1549 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1550 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1551 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1552 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1553 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1558 /* This function implements the "verify" condition. It is called when
1559 encountered in any ACL, because some tests are almost always permitted. Some
1560 just don't make sense, and always fail (for example, an attempt to test a host
1561 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1564 where where called from
1565 addr the recipient address that the ACL is handling, or NULL
1566 arg the argument of "verify"
1567 user_msgptr pointer for user message
1568 log_msgptr pointer for log message
1569 basic_errno where to put verify errno
1571 Returns: OK verification condition succeeded
1572 FAIL verification failed
1573 DEFER there was a problem verifying
1578 acl_verify(int where, address_item *addr, const uschar *arg,
1579 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1583 int callout_overall = -1;
1584 int callout_connect = -1;
1585 int verify_options = 0;
1587 BOOL verify_header_sender = FALSE;
1588 BOOL defer_ok = FALSE;
1589 BOOL callout_defer_ok = FALSE;
1590 BOOL no_details = FALSE;
1591 BOOL success_on_redirect = FALSE;
1592 address_item *sender_vaddr = NULL;
1593 uschar *verify_sender_address = NULL;
1594 uschar *pm_mailfrom = NULL;
1595 uschar *se_mailfrom = NULL;
1597 /* Some of the verify items have slash-separated options; some do not. Diagnose
1598 an error if options are given for items that don't expect them.
1601 uschar *slash = Ustrchr(arg, '/');
1602 const uschar *list = arg;
1603 uschar *ss = string_nextinlist(&list, &sep, NULL, 0);
1606 if (!ss) goto BAD_VERIFY;
1608 /* Handle name/address consistency verification in a separate function. */
1610 for (vp = verify_type_list;
1611 CS vp < CS verify_type_list + sizeof(verify_type_list);
1614 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1615 : strcmpic (ss, vp->name) == 0)
1617 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1620 if (vp->no_options && slash)
1622 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1623 "(this verify item has no options)", arg);
1626 if (!(vp->where_allowed & BIT(where)))
1628 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1629 vp->name, acl_wherenames[where]);
1634 case VERIFY_REV_HOST_LKUP:
1635 if (!sender_host_address) return OK;
1636 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1637 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1638 if (strcmpic(ss, US"defer_ok") == 0)
1643 /* TLS certificate verification is done at STARTTLS time; here we just
1644 test whether it was successful or not. (This is for optional verification; for
1645 mandatory verification, the connection doesn't last this long.) */
1647 if (tls_in.certificate_verified) return OK;
1648 *user_msgptr = US"no verified certificate";
1652 /* We can test the result of optional HELO verification that might have
1653 occurred earlier. If not, we can attempt the verification now. */
1655 if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo();
1656 return f.helo_verified ? OK : FAIL;
1659 /* Do Client SMTP Authorization checks in a separate function, and turn the
1660 result code into user-friendly strings. */
1662 rc = acl_verify_csa(list);
1663 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1664 csa_reason_string[rc]);
1665 csa_status = csa_status_string[rc];
1666 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1667 return csa_return_code[rc];
1669 #ifdef EXPERIMENTAL_ARC
1671 { /* Do Authenticated Received Chain checks in a separate function. */
1672 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1676 if (!(arc_state = acl_verify_arc())) return DEFER;
1677 DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state,
1678 arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":"");
1680 if (!condlist) condlist = US"none:pass";
1681 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1682 if (Ustrcmp(arc_state, cond) == 0) return OK;
1687 case VERIFY_HDR_SYNTAX:
1688 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1689 a syntax error, we return details of the error to the sender if configured to
1690 send out full details. (But a "message" setting on the ACL can override, as
1693 rc = verify_check_headers(log_msgptr);
1694 if (rc != OK && *log_msgptr)
1695 if (smtp_return_error_details)
1696 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1698 acl_verify_message = *log_msgptr;
1701 case VERIFY_HDR_NAMES_ASCII:
1702 /* Check that all header names are true 7 bit strings
1703 See RFC 5322, 2.2. and RFC 6532, 3. */
1705 rc = verify_check_header_names_ascii(log_msgptr);
1706 if (rc != OK && smtp_return_error_details && *log_msgptr)
1707 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1710 case VERIFY_NOT_BLIND:
1711 /* Check that no recipient of this message is "blind", that is, every envelope
1712 recipient must be mentioned in either To: or Cc:. */
1714 BOOL case_sensitive = TRUE;
1716 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1717 if (strcmpic(ss, US"case_insensitive") == 0)
1718 case_sensitive = FALSE;
1721 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1722 "condition \"verify %s\"", ss, arg);
1726 if ((rc = verify_check_notblind(case_sensitive)) != OK)
1728 *log_msgptr = US"bcc recipient detected";
1729 if (smtp_return_error_details)
1730 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1735 /* The remaining verification tests check recipient and sender addresses,
1736 either from the envelope or from the header. There are a number of
1737 slash-separated options that are common to all of them. */
1739 case VERIFY_HDR_SNDR:
1740 verify_header_sender = TRUE;
1744 /* In the case of a sender, this can optionally be followed by an address to use
1745 in place of the actual sender (rare special-case requirement). */
1749 verify_sender_address = sender_address;
1752 while (isspace(*s)) s++;
1753 if (*s++ != '=') goto BAD_VERIFY;
1754 while (isspace(*s)) s++;
1755 verify_sender_address = string_copy(s);
1766 /* Remaining items are optional; they apply to sender and recipient
1767 verification, including "header sender" verification. */
1769 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1771 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1772 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1773 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1775 /* These two old options are left for backwards compatibility */
1777 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1779 callout_defer_ok = TRUE;
1780 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1783 else if (strcmpic(ss, US"check_postmaster") == 0)
1786 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1789 /* The callout option has a number of sub-options, comma separated */
1791 else if (strncmpic(ss, US"callout", 7) == 0)
1793 callout = CALLOUT_TIMEOUT_DEFAULT;
1797 while (isspace(*ss)) ss++;
1800 const uschar * sublist = ss;
1805 while (isspace(*sublist)) sublist++;
1806 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1809 double period = 1.0F;
1811 for (op= callout_opt_list; op->name; op++)
1812 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1815 verify_options |= op->flag;
1818 opt += Ustrlen(op->name);
1819 while (isspace(*opt)) opt++;
1822 *log_msgptr = string_sprintf("'=' expected after "
1823 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1826 while (isspace(*opt)) opt++;
1828 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1830 *log_msgptr = string_sprintf("bad time value in ACL condition "
1831 "\"verify %s\"", arg);
1837 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1838 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1839 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1840 case CALLOUT_MAILFROM:
1841 if (!verify_header_sender)
1843 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1844 "callout option only for verify=header_sender (detected in ACL "
1845 "condition \"%s\")", arg);
1848 se_mailfrom = string_copy(opt);
1850 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1851 case CALLOUT_MAXWAIT: callout_overall = period; break;
1852 case CALLOUT_CONNECT: callout_connect = period; break;
1853 case CALLOUT_TIME: callout = period; break;
1859 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1860 "ACL condition \"%s\"", arg);
1866 /* Option not recognized */
1870 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1871 "condition \"verify %s\"", ss, arg);
1876 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1877 (vopt_callout_recipsender|vopt_callout_recippmaster))
1879 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1880 "for a recipient callout";
1884 /* Handle sender-in-header verification. Default the user message to the log
1885 message if giving out verification details. */
1887 if (verify_header_sender)
1891 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1892 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1895 *basic_errno = verrno;
1896 if (smtp_return_error_details)
1898 if (!*user_msgptr && *log_msgptr)
1899 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1900 if (rc == DEFER) f.acl_temp_details = TRUE;
1905 /* Handle a sender address. The default is to verify *the* sender address, but
1906 optionally a different address can be given, for special requirements. If the
1907 address is empty, we are dealing with a bounce message that has no sender, so
1908 we cannot do any checking. If the real sender address gets rewritten during
1909 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1910 during message reception.
1912 A list of verified "sender" addresses is kept to try to avoid doing to much
1913 work repetitively when there are multiple recipients in a message and they all
1914 require sender verification. However, when callouts are involved, it gets too
1915 complicated because different recipients may require different callout options.
1916 Therefore, we always do a full sender verify when any kind of callout is
1917 specified. Caching elsewhere, for instance in the DNS resolver and in the
1918 callout handling, should ensure that this is not terribly inefficient. */
1920 else if (verify_sender_address)
1922 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1924 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1925 "sender verify callout";
1929 sender_vaddr = verify_checked_sender(verify_sender_address);
1930 if (sender_vaddr != NULL && /* Previously checked */
1931 callout <= 0) /* No callout needed this time */
1933 /* If the "routed" flag is set, it means that routing worked before, so
1934 this check can give OK (the saved return code value, if set, belongs to a
1935 callout that was done previously). If the "routed" flag is not set, routing
1936 must have failed, so we use the saved return code. */
1938 if (testflag(sender_vaddr, af_verify_routed))
1942 rc = sender_vaddr->special_action;
1943 *basic_errno = sender_vaddr->basic_errno;
1945 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1948 /* Do a new verification, and cache the result. The cache is used to avoid
1949 verifying the sender multiple times for multiple RCPTs when callouts are not
1950 specified (see comments above).
1952 The cache is also used on failure to give details in response to the first
1953 RCPT that gets bounced for this reason. However, this can be suppressed by
1954 the no_details option, which sets the flag that says "this detail has already
1955 been sent". The cache normally contains just one address, but there may be
1956 more in esoteric circumstances. */
1961 uschar *save_address_data = deliver_address_data;
1963 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1965 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1967 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1968 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1971 if (no_details) setflag(sender_vaddr, af_sverify_told);
1972 if (verify_sender_address[0] != 0)
1974 /* If this is the real sender address, save the unrewritten version
1975 for use later in receive. Otherwise, set a flag so that rewriting the
1976 sender in verify_address() does not update sender_address. */
1978 if (verify_sender_address == sender_address)
1979 sender_address_unrewritten = sender_address;
1981 verify_options |= vopt_fake_sender;
1983 if (success_on_redirect)
1984 verify_options |= vopt_success_on_redirect;
1986 /* The recipient, qualify, and expn options are never set in
1989 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1990 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1992 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
1995 *basic_errno = sender_vaddr->basic_errno;
1999 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2000 debug_printf_indent("sender %s verified ok as %s\n",
2001 verify_sender_address, sender_vaddr->address);
2003 debug_printf_indent("sender %s verified ok\n",
2004 verify_sender_address);
2008 rc = OK; /* Null sender */
2010 /* Cache the result code */
2012 if (routed) setflag(sender_vaddr, af_verify_routed);
2013 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2014 sender_vaddr->special_action = rc;
2015 sender_vaddr->next = sender_verified_list;
2016 sender_verified_list = sender_vaddr;
2018 /* Restore the recipient address data, which might have been clobbered by
2019 the sender verification. */
2021 deliver_address_data = save_address_data;
2024 /* Put the sender address_data value into $sender_address_data */
2026 sender_address_data = sender_vaddr->prop.address_data;
2029 /* A recipient address just gets a straightforward verify; again we must handle
2030 the DEFER overrides. */
2036 if (success_on_redirect)
2037 verify_options |= vopt_success_on_redirect;
2039 /* We must use a copy of the address for verification, because it might
2043 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2044 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2045 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2047 *basic_errno = addr2.basic_errno;
2048 *log_msgptr = addr2.message;
2049 *user_msgptr = (addr2.user_message != NULL)?
2050 addr2.user_message : addr2.message;
2052 /* Allow details for temporary error if the address is so flagged. */
2053 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2055 /* Make $address_data visible */
2056 deliver_address_data = addr2.prop.address_data;
2059 /* We have a result from the relevant test. Handle defer overrides first. */
2061 if (rc == DEFER && (defer_ok ||
2062 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2064 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2065 defer_ok? "defer_ok" : "callout_defer_ok");
2069 /* If we've failed a sender, set up a recipient message, and point
2070 sender_verified_failed to the address item that actually failed. */
2072 if (rc != OK && verify_sender_address != NULL)
2075 *log_msgptr = *user_msgptr = US"Sender verify failed";
2076 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2077 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2080 *log_msgptr = US"Could not complete sender verify callout";
2081 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2085 sender_verified_failed = sender_vaddr;
2088 /* Verifying an address messes up the values of $domain and $local_part,
2089 so reset them before returning if this is a RCPT ACL. */
2093 deliver_domain = addr->domain;
2094 deliver_localpart = addr->local_part;
2098 /* Syntax errors in the verify argument come here. */
2101 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2102 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2103 "or \"reverse_host_lookup\" at start of ACL condition "
2104 "\"verify %s\"", arg);
2111 /*************************************************
2112 * Check argument for control= modifier *
2113 *************************************************/
2115 /* Called from acl_check_condition() below.
2116 To handle the case "queue_only" we accept an _ in the
2117 initial / option-switch position.
2120 arg the argument string for control=
2121 pptr set to point to the terminating character
2122 where which ACL we are in
2123 log_msgptr for error messages
2125 Returns: CONTROL_xxx value
2129 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2135 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2136 || ( (c = arg[len = Ustrlen((d = controls_list+idx)->name)]) != 0
2137 && (!d->has_option || c != '/' && c != '_')
2140 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2141 return CONTROL_ERROR;
2151 /*************************************************
2152 * Return a ratelimit error *
2153 *************************************************/
2155 /* Called from acl_ratelimit() below
2158 log_msgptr for error messages
2159 format format string
2160 ... supplementary arguments
2166 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2170 string_cat(NULL, US"error in arguments to \"ratelimit\" condition: ");
2172 va_start(ap, format);
2173 g = string_vformat(g, SVFMT_EXTEND|SVFMT_REBUFFER, format, ap);
2176 gstring_release_unused(g);
2177 *log_msgptr = string_from_gstring(g);
2184 /*************************************************
2185 * Handle rate limiting *
2186 *************************************************/
2188 /* Called by acl_check_condition() below to calculate the result
2189 of the ACL ratelimit condition.
2191 Note that the return value might be slightly unexpected: if the
2192 sender's rate is above the limit then the result is OK. This is
2193 similar to the dnslists condition, and is so that you can write
2194 ACL clauses like: defer ratelimit = 15 / 1h
2197 arg the option string for ratelimit=
2198 where ACL_WHERE_xxxx indicating which ACL this is
2199 log_msgptr for error messages
2201 Returns: OK - Sender's rate is above limit
2202 FAIL - Sender's rate is below limit
2203 DEFER - Problem opening ratelimit database
2204 ERROR - Syntax error in options.
2208 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2210 double limit, period, count;
2213 uschar *unique = NULL;
2215 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2216 BOOL noupdate = FALSE, badacl = FALSE;
2217 int mode = RATE_PER_WHAT;
2219 tree_node **anchor, *t;
2220 open_db dbblock, *dbm;
2222 dbdata_ratelimit *dbd;
2223 dbdata_ratelimit_unique *dbdb;
2226 /* Parse the first two options and record their values in expansion
2227 variables. These variables allow the configuration to have informative
2228 error messages based on rate limits obtained from a table lookup. */
2230 /* First is the maximum number of messages per period / maximum burst
2231 size, which must be greater than or equal to zero. Zero is useful for
2232 rate measurement as opposed to rate limiting. */
2234 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2235 return ratelimit_error(log_msgptr, "sender rate limit not set");
2237 limit = Ustrtod(sender_rate_limit, &ss);
2238 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2239 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2240 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2242 if (limit < 0.0 || *ss != '\0')
2243 return ratelimit_error(log_msgptr,
2244 "\"%s\" is not a positive number", sender_rate_limit);
2246 /* Second is the rate measurement period / exponential smoothing time
2247 constant. This must be strictly greater than zero, because zero leads to
2248 run-time division errors. */
2250 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2251 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2253 return ratelimit_error(log_msgptr,
2254 "\"%s\" is not a time value", sender_rate_period);
2256 /* By default we are counting one of something, but the per_rcpt,
2257 per_byte, and count options can change this. */
2261 /* Parse the other options. */
2263 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)))
2265 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2266 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2267 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2268 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2269 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2270 else if (strcmpic(ss, US"per_conn") == 0)
2272 RATE_SET(mode, PER_CONN);
2273 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2276 else if (strcmpic(ss, US"per_mail") == 0)
2278 RATE_SET(mode, PER_MAIL);
2279 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2281 else if (strcmpic(ss, US"per_rcpt") == 0)
2283 /* If we are running in the RCPT ACL, then we'll count the recipients
2284 one by one, but if we are running when we have accumulated the whole
2285 list then we'll add them all in one batch. */
2286 if (where == ACL_WHERE_RCPT)
2287 RATE_SET(mode, PER_RCPT);
2288 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2289 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2290 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2291 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2293 else if (strcmpic(ss, US"per_byte") == 0)
2295 /* If we have not yet received the message data and there was no SIZE
2296 declaration on the MAIL command, then it's safe to just use a value of
2297 zero and let the recorded rate decay as if nothing happened. */
2298 RATE_SET(mode, PER_MAIL);
2299 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2300 else count = message_size < 0 ? 0.0 : (double)message_size;
2302 else if (strcmpic(ss, US"per_addr") == 0)
2304 RATE_SET(mode, PER_RCPT);
2305 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2306 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2308 else if (strncmpic(ss, US"count=", 6) == 0)
2311 count = Ustrtod(ss+6, &e);
2312 if (count < 0.0 || *e != '\0')
2313 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2315 else if (strncmpic(ss, US"unique=", 7) == 0)
2316 unique = string_copy(ss + 7);
2318 key = string_copy(ss);
2320 key = string_sprintf("%s/%s", key, ss);
2323 /* Sanity check. When the badacl flag is set the update mode must either
2324 be readonly (which is the default if it is omitted) or, for backwards
2325 compatibility, a combination of noupdate and strict or leaky. */
2327 if (mode == RATE_PER_CLASH)
2328 return ratelimit_error(log_msgptr, "conflicting per_* options");
2329 if (leaky + strict + readonly > 1)
2330 return ratelimit_error(log_msgptr, "conflicting update modes");
2331 if (badacl && (leaky || strict) && !noupdate)
2332 return ratelimit_error(log_msgptr,
2333 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2334 ratelimit_option_string[mode], acl_wherenames[where]);
2336 /* Set the default values of any unset options. In readonly mode we
2337 perform the rate computation without any increment so that its value
2338 decays to eventually allow over-limit senders through. */
2340 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2341 if (badacl) readonly = TRUE;
2342 if (readonly) count = 0.0;
2343 if (!strict && !readonly) leaky = TRUE;
2344 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2346 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2347 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2348 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2349 are added to the key because they alter the meaning of the stored data. */
2352 key = !sender_host_address ? US"" : sender_host_address;
2354 key = string_sprintf("%s/%s/%s%s",
2356 ratelimit_option_string[mode],
2357 unique == NULL ? "" : "unique/",
2361 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2363 /* See if we have already computed the rate by looking in the relevant tree.
2364 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2365 pool so that they survive across resets. In readonly mode we only remember the
2366 result for the rest of this command in case a later command changes it. After
2367 this bit of logic the code is independent of the per_* mode. */
2369 old_pool = store_pool;
2372 anchor = &ratelimiters_cmd;
2376 anchor = &ratelimiters_conn;
2377 store_pool = POOL_PERM;
2381 case RATE_PER_ALLRCPTS:
2382 anchor = &ratelimiters_mail;
2387 anchor = &ratelimiters_cmd;
2390 anchor = NULL; /* silence an "unused" complaint */
2391 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2392 "internal ACL error: unknown ratelimit mode %d", mode);
2396 if ((t = tree_search(*anchor, key)))
2399 /* The following few lines duplicate some of the code below. */
2400 rc = (dbd->rate < limit)? FAIL : OK;
2401 store_pool = old_pool;
2402 sender_rate = string_sprintf("%.1f", dbd->rate);
2404 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2408 /* We aren't using a pre-computed rate, so get a previously recorded rate
2409 from the database, which will be updated and written back if required. */
2411 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE, TRUE)))
2413 store_pool = old_pool;
2415 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2416 *log_msgptr = US"ratelimit database not available";
2419 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2422 gettimeofday(&tv, NULL);
2426 /* Locate the basic ratelimit block inside the DB data. */
2427 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2430 /* Forget the old Bloom filter if it is too old, so that we count each
2431 repeating event once per period. We don't simply clear and re-use the old
2432 filter because we want its size to change if the limit changes. Note that
2433 we keep the dbd pointer for copying the rate into the new data block. */
2435 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2437 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2443 if(unique && dbdb_size < sizeof(*dbdb))
2445 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2450 /* Allocate a new data block if the database lookup failed
2451 or the Bloom filter passed its age limit. */
2457 /* No Bloom filter. This basic ratelimit block is initialized below. */
2458 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2459 dbdb_size = sizeof(*dbd);
2460 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2465 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2467 /* See the long comment below for an explanation of the magic number 2.
2468 The filter has a minimum size in case the rate limit is very small;
2469 this is determined by the definition of dbdata_ratelimit_unique. */
2471 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2472 if (extra < 0) extra = 0;
2473 dbdb_size = sizeof(*dbdb) + extra;
2474 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2475 dbdb->bloom_epoch = tv.tv_sec;
2476 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2477 memset(dbdb->bloom, 0, dbdb->bloom_size);
2479 /* Preserve any basic ratelimit data (which is our longer-term memory)
2480 by copying it from the discarded block. */
2490 /* If we are counting unique events, find out if this event is new or not.
2491 If the client repeats the event during the current period then it should be
2492 counted. We skip this code in readonly mode for efficiency, because any
2493 changes to the filter will be discarded and because count is already set to
2496 if (unique && !readonly)
2498 /* We identify unique events using a Bloom filter. (You can find my
2499 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2500 With the per_addr option, an "event" is a recipient address, though the
2501 user can use the unique option to define their own events. We only count
2502 an event if we have not seen it before.
2504 We size the filter according to the rate limit, which (in leaky mode)
2505 is the limit on the population of the filter. We allow 16 bits of space
2506 per entry (see the construction code above) and we set (up to) 8 of them
2507 when inserting an element (see the loop below). The probability of a false
2508 positive (an event we have not seen before but which we fail to count) is
2512 allzero = exp(-numhash * pop / size)
2513 = exp(-0.5 * pop / limit)
2514 fpr = pow(1 - allzero, numhash)
2516 For senders at the limit the fpr is 0.06% or 1 in 1700
2517 and for senders at half the limit it is 0.0006% or 1 in 170000
2519 In strict mode the Bloom filter can fill up beyond the normal limit, in
2520 which case the false positive rate will rise. This means that the
2521 measured rate for very fast senders can bogusly drop off after a while.
2523 At twice the limit, the fpr is 2.5% or 1 in 40
2524 At four times the limit, it is 31% or 1 in 3.2
2526 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2527 decay below the limit, and if this is more than one then the Bloom filter
2528 will be discarded before the decay gets that far. The false positive rate
2529 at this threshold is 9.3% or 1 in 10.7. */
2532 unsigned n, hash, hinc;
2536 /* Instead of using eight independent hash values, we combine two values
2537 using the formula h1 + n * h2. This does not harm the Bloom filter's
2538 performance, and means the amount of hash we need is independent of the
2539 number of bits we set in the filter. */
2541 md5_start(&md5info);
2542 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2543 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2544 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2546 /* Scan the bits corresponding to this event. A zero bit means we have
2547 not seen it before. Ensure all bits are set to record this event. */
2549 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2552 for (n = 0; n < 8; n++, hash += hinc)
2554 int bit = 1 << (hash % 8);
2555 int byte = (hash / 8) % dbdb->bloom_size;
2556 if ((dbdb->bloom[byte] & bit) == 0)
2558 dbdb->bloom[byte] |= bit;
2563 /* If this event has occurred before, do not count it. */
2567 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2571 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2574 /* If there was no previous ratelimit data block for this key, initialize
2575 the new one, otherwise update the block from the database. The initial rate
2576 is what would be computed by the code below for an infinite interval. */
2580 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2582 dbd->time_stamp = tv.tv_sec;
2583 dbd->time_usec = tv.tv_usec;
2588 /* The smoothed rate is computed using an exponentially weighted moving
2589 average adjusted for variable sampling intervals. The standard EWMA for
2590 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2591 where f() is the measured value and f'() is the smoothed value.
2593 Old data decays out of the smoothed value exponentially, such that data n
2594 samples old is multiplied by a^n. The exponential decay time constant p
2595 is defined such that data p samples old is multiplied by 1/e, which means
2596 that a = exp(-1/p). We can maintain the same time constant for a variable
2597 sampling interval i by using a = exp(-i/p).
2599 The rate we are measuring is messages per period, suitable for directly
2600 comparing with the limit. The average rate between now and the previous
2601 message is period / interval, which we feed into the EWMA as the sample.
2603 It turns out that the number of messages required for the smoothed rate
2604 to reach the limit when they are sent in a burst is equal to the limit.
2605 This can be seen by analysing the value of the smoothed rate after N
2606 messages sent at even intervals. Let k = (1 - a) * p/i
2608 rate_1 = (1 - a) * p/i + a * rate_0
2610 rate_2 = k + a * rate_1
2611 = k + a * k + a^2 * rate_0
2612 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2613 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2614 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2615 = rate_0 * a^N + p/i * (1 - a^N)
2617 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2619 rate_N = p/i + (rate_0 - p/i) * a^N
2620 a^N = (rate_N - p/i) / (rate_0 - p/i)
2621 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2622 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2624 Numerical analysis of the above equation, setting the computed rate to
2625 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2626 rates, p/i, the number of messages N = limit. So limit serves as both the
2627 maximum rate measured in messages per period, and the maximum number of
2628 messages that can be sent in a fast burst. */
2630 double this_time = (double)tv.tv_sec
2631 + (double)tv.tv_usec / 1000000.0;
2632 double prev_time = (double)dbd->time_stamp
2633 + (double)dbd->time_usec / 1000000.0;
2635 /* We must avoid division by zero, and deal gracefully with the clock going
2636 backwards. If we blunder ahead when time is in reverse then the computed
2637 rate will be bogus. To be safe we clamp interval to a very small number. */
2639 double interval = this_time - prev_time <= 0.0 ? 1e-9
2640 : this_time - prev_time;
2642 double i_over_p = interval / period;
2643 double a = exp(-i_over_p);
2645 /* Combine the instantaneous rate (period / interval) with the previous rate
2646 using the smoothing factor a. In order to measure sized events, multiply the
2647 instantaneous rate by the count of bytes or recipients etc. */
2649 dbd->time_stamp = tv.tv_sec;
2650 dbd->time_usec = tv.tv_usec;
2651 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2653 /* When events are very widely spaced the computed rate tends towards zero.
2654 Although this is accurate it turns out not to be useful for our purposes,
2655 especially when the first event after a long silence is the start of a spam
2656 run. A more useful model is that the rate for an isolated event should be the
2657 size of the event per the period size, ignoring the lack of events outside
2658 the current period and regardless of where the event falls in the period. So,
2659 if the interval was so long that the calculated rate is unhelpfully small, we
2660 re-initialize the rate. In the absence of higher-rate bursts, the condition
2661 below is true if the interval is greater than the period. */
2663 if (dbd->rate < count) dbd->rate = count;
2666 /* Clients sending at the limit are considered to be over the limit.
2667 This matters for edge cases such as a limit of zero, when the client
2668 should be completely blocked. */
2670 rc = dbd->rate < limit ? FAIL : OK;
2672 /* Update the state if the rate is low or if we are being strict. If we
2673 are in leaky mode and the sender's rate is too high, we do not update
2674 the recorded rate in order to avoid an over-aggressive sender's retry
2675 rate preventing them from getting any email through. If readonly is set,
2676 neither leaky nor strict are set, so we do not do any updates. */
2678 if ((rc == FAIL && leaky) || strict)
2680 dbfn_write(dbm, key, dbdb, dbdb_size);
2681 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2685 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2686 readonly? "readonly mode" : "over the limit, but leaky");
2691 /* Store the result in the tree for future reference. Take the taint status
2692 from the key for consistency even though it's unlikely we'll ever expand this. */
2694 t = store_get(sizeof(tree_node) + Ustrlen(key), is_tainted(key));
2696 Ustrcpy(t->name, key);
2697 (void)tree_insertnode(anchor, t);
2699 /* We create the formatted version of the sender's rate very late in
2700 order to ensure that it is done using the correct storage pool. */
2702 store_pool = old_pool;
2703 sender_rate = string_sprintf("%.1f", dbd->rate);
2706 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2713 /*************************************************
2714 * The udpsend ACL modifier *
2715 *************************************************/
2717 /* Called by acl_check_condition() below.
2720 arg the option string for udpsend=
2721 log_msgptr for error messages
2723 Returns: OK - Completed.
2724 DEFER - Problem with DNS lookup.
2725 ERROR - Syntax error in options.
2729 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2741 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2742 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2746 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2751 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2756 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2759 portnum = Ustrtol(portstr, &portend, 10);
2760 if (*portend != '\0')
2762 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2766 /* Make a single-item host list. */
2767 h = store_get(sizeof(host_item), FALSE);
2768 memset(h, 0, sizeof(host_item));
2773 if (string_is_ip_address(hostname, NULL))
2774 h->address = hostname, r = HOST_FOUND;
2776 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2777 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2779 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2784 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2786 /*XXX this could better use sendto */
2787 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2788 1, NULL, &errstr, NULL);
2789 if (r < 0) goto defer;
2791 r = send(s, arg, len, 0);
2794 errstr = US strerror(errno);
2802 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2807 debug_printf_indent("udpsend %d bytes\n", r);
2812 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2818 /*************************************************
2819 * Handle conditions/modifiers on an ACL item *
2820 *************************************************/
2822 /* Called from acl_check() below.
2826 cb ACL condition block - if NULL, result is OK
2827 where where called from
2828 addr the address being checked for RCPT, or NULL
2829 level the nesting level
2830 epp pointer to pass back TRUE if "endpass" encountered
2831 (applies only to "accept" and "discard")
2832 user_msgptr user message pointer
2833 log_msgptr log message pointer
2834 basic_errno pointer to where to put verify error
2836 Returns: OK - all conditions are met
2837 DISCARD - an "acl" condition returned DISCARD - only allowed
2838 for "accept" or "discard" verbs
2839 FAIL - at least one condition fails
2840 FAIL_DROP - an "acl" condition returned FAIL_DROP
2841 DEFER - can't tell at the moment (typically, lookup defer,
2842 but can be temporary callout problem)
2843 ERROR - ERROR from nested ACL or expansion failure or other
2848 acl_check_condition(int verb, acl_condition_block *cb, int where,
2849 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2850 uschar **log_msgptr, int *basic_errno)
2852 uschar *user_message = NULL;
2853 uschar *log_message = NULL;
2855 #ifdef WITH_CONTENT_SCAN
2859 for (; cb; cb = cb->next)
2864 /* The message and log_message items set up messages to be used in
2865 case of rejection. They are expanded later. */
2867 if (cb->type == ACLC_MESSAGE)
2869 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2870 user_message = cb->arg;
2874 if (cb->type == ACLC_LOG_MESSAGE)
2876 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2877 log_message = cb->arg;
2881 /* The endpass "condition" just sets a flag to show it occurred. This is
2882 checked at compile time to be on an "accept" or "discard" item. */
2884 if (cb->type == ACLC_ENDPASS)
2890 /* For other conditions and modifiers, the argument is expanded now for some
2891 of them, but not for all, because expansion happens down in some lower level
2892 checking functions in some cases. */
2894 if (!conditions[cb->type].expand_at_top)
2896 else if (!(arg = expand_string(cb->arg)))
2898 if (f.expand_string_forcedfail) continue;
2899 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2900 cb->arg, expand_string_message);
2901 return f.search_find_defer ? DEFER : ERROR;
2904 /* Show condition, and expanded condition if it's different */
2909 debug_printf_indent("check %s%s %n",
2910 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2911 conditions[cb->type].name, &lhswidth);
2913 if (cb->type == ACLC_SET)
2915 #ifndef DISABLE_DKIM
2916 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2917 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2919 debug_printf("%s ", cb->u.varname);
2925 debug_printf("acl_%s ", cb->u.varname);
2926 lhswidth += 5 + Ustrlen(cb->u.varname);
2930 debug_printf("= %s\n", cb->arg);
2933 debug_printf("%.*s= %s\n", lhswidth,
2937 /* Check that this condition makes sense at this time */
2939 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2941 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2942 conditions[cb->type].is_modifier ? "use" : "test",
2943 conditions[cb->type].name, acl_wherenames[where]);
2947 /* Run the appropriate test for each condition, or take the appropriate
2948 action for the remaining modifiers. */
2952 case ACLC_ADD_HEADER:
2956 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2960 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2961 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2963 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2964 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2970 case ACLC_AUTHENTICATED:
2971 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
2972 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
2975 #ifdef EXPERIMENTAL_BRIGHTMAIL
2976 case ACLC_BMI_OPTIN:
2978 int old_pool = store_pool;
2979 store_pool = POOL_PERM;
2980 bmi_current_optin = string_copy(arg);
2981 store_pool = old_pool;
2986 case ACLC_CONDITION:
2987 /* The true/false parsing here should be kept in sync with that used in
2988 expand.c when dealing with ECOND_BOOL so that we don't have too many
2989 different definitions of what can be a boolean. */
2991 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
2992 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2993 rc = (Uatoi(arg) == 0)? FAIL : OK;
2995 rc = (strcmpic(arg, US"no") == 0 ||
2996 strcmpic(arg, US"false") == 0)? FAIL :
2997 (strcmpic(arg, US"yes") == 0 ||
2998 strcmpic(arg, US"true") == 0)? OK : DEFER;
3000 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3003 case ACLC_CONTINUE: /* Always succeeds */
3008 const uschar *p = NULL;
3009 control_type = decode_control(arg, &p, where, log_msgptr);
3011 /* Check if this control makes sense at this time */
3013 if (controls_list[control_type].forbids & (1 << where))
3015 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3016 controls_list[control_type].name, acl_wherenames[where]);
3020 switch(control_type)
3022 case CONTROL_AUTH_UNADVERTISED:
3023 f.allow_auth_unadvertised = TRUE;
3026 #ifdef EXPERIMENTAL_BRIGHTMAIL
3027 case CONTROL_BMI_RUN:
3032 #ifndef DISABLE_DKIM
3033 case CONTROL_DKIM_VERIFY:
3034 f.dkim_disable_verify = TRUE;
3035 # ifdef SUPPORT_DMARC
3036 /* Since DKIM was blocked, skip DMARC too */
3037 f.dmarc_disable_verify = TRUE;
3038 f.dmarc_enable_forensic = FALSE;
3043 #ifdef SUPPORT_DMARC
3044 case CONTROL_DMARC_VERIFY:
3045 f.dmarc_disable_verify = TRUE;
3048 case CONTROL_DMARC_FORENSIC:
3049 f.dmarc_enable_forensic = TRUE;
3056 int fd, af, level, optname, value;
3057 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3058 a socket; we can accept that, we'll just debug-log failures anyway. */
3059 fd = fileno(smtp_in);
3060 if ((af = ip_get_address_family(fd)) < 0)
3063 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3067 if (dscp_lookup(p+1, af, &level, &optname, &value))
3068 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3070 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3071 p+1, strerror(errno));
3075 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3079 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3085 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3093 case CONTROL_CASEFUL_LOCAL_PART:
3094 deliver_localpart = addr->cc_local_part;
3097 case CONTROL_CASELOWER_LOCAL_PART:
3098 deliver_localpart = addr->lc_local_part;
3101 case CONTROL_ENFORCE_SYNC:
3102 smtp_enforce_sync = TRUE;
3105 case CONTROL_NO_ENFORCE_SYNC:
3106 smtp_enforce_sync = FALSE;
3109 #ifdef WITH_CONTENT_SCAN
3110 case CONTROL_NO_MBOX_UNSPOOL:
3111 f.no_mbox_unspool = TRUE;
3115 case CONTROL_NO_MULTILINE:
3116 f.no_multiline_responses = TRUE;
3119 case CONTROL_NO_PIPELINING:
3120 f.pipelining_enable = FALSE;
3123 case CONTROL_NO_DELAY_FLUSH:
3124 f.disable_delay_flush = TRUE;
3127 case CONTROL_NO_CALLOUT_FLUSH:
3128 f.disable_callout_flush = TRUE;
3131 case CONTROL_FAKEREJECT:
3132 cancel_cutthrough_connection(TRUE, US"fakereject");
3133 case CONTROL_FAKEDEFER:
3134 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3137 const uschar *pp = p + 1;
3139 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3142 else /* Explicitly reset to default string */
3143 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).";
3146 case CONTROL_FREEZE:
3147 f.deliver_freeze = TRUE;
3148 deliver_frozen_at = time(NULL);
3149 freeze_tell = freeze_tell_config; /* Reset to configured value */
3150 if (Ustrncmp(p, "/no_tell", 8) == 0)
3157 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3160 cancel_cutthrough_connection(TRUE, US"item frozen");
3164 f.queue_only_policy = TRUE;
3165 if (Ustrcmp(p, "_only") == 0)
3167 else while (*p == '/')
3168 if (Ustrncmp(p, "/only", 5) == 0)
3169 { p += 5; f.queue_smtp = FALSE; }
3170 else if (Ustrncmp(p, "/first_pass_route", 17) == 0)
3171 { p += 17; f.queue_smtp = TRUE; }
3174 cancel_cutthrough_connection(TRUE, US"queueing forced");
3177 case CONTROL_SUBMISSION:
3178 originator_name = US"";
3179 f.submission_mode = TRUE;
3182 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3185 f.active_local_sender_retain = TRUE;
3186 f.active_local_from_check = FALSE;
3188 else if (Ustrncmp(p, "/domain=", 8) == 0)
3190 const uschar *pp = p + 8;
3191 while (*pp && *pp != '/') pp++;
3192 submission_domain = string_copyn(p+8, pp-p-8);
3195 /* The name= option must be last, because it swallows the rest of
3197 else if (Ustrncmp(p, "/name=", 6) == 0)
3199 const uschar *pp = p + 6;
3201 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3202 big_buffer, big_buffer_size));
3209 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3216 uschar * debug_tag = NULL;
3217 uschar * debug_opts = NULL;
3222 const uschar * pp = p+1;
3223 if (Ustrncmp(pp, "tag=", 4) == 0)
3225 for (pp += 4; *pp && *pp != '/';) pp++;
3226 debug_tag = string_copyn(p+5, pp-p-5);
3228 else if (Ustrncmp(pp, "opts=", 5) == 0)
3230 for (pp += 5; *pp && *pp != '/';) pp++;
3231 debug_opts = string_copyn(p+6, pp-p-6);
3233 else if (Ustrncmp(pp, "kill", 4) == 0)
3235 for (pp += 4; *pp && *pp != '/';) pp++;
3239 while (*pp && *pp != '/') pp++;
3244 debug_logging_stop();
3246 debug_logging_activate(debug_tag, debug_opts);
3250 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3251 f.suppress_local_fixups = TRUE;
3254 case CONTROL_CUTTHROUGH_DELIVERY:
3256 uschar * ignored = NULL;
3257 #ifndef DISABLE_PRDR
3262 /* Too hard to think about for now. We might in future cutthrough
3263 the case where both sides handle prdr and this-node prdr acl
3265 ignored = US"PRDR active";
3268 if (f.deliver_freeze)
3269 ignored = US"frozen";
3270 else if (f.queue_only_policy)
3271 ignored = US"queue-only";
3272 else if (fake_response == FAIL)
3273 ignored = US"fakereject";
3276 if (rcpt_count == 1)
3278 cutthrough.delivery = TRUE; /* control accepted */
3281 const uschar * pp = p+1;
3282 if (Ustrncmp(pp, "defer=", 6) == 0)
3285 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3286 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3289 while (*pp && *pp != '/') pp++;
3294 ignored = US"nonfirst rcpt";
3297 DEBUG(D_acl) if (ignored)
3298 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3303 case CONTROL_UTF8_DOWNCONVERT:
3308 message_utf8_downconvert = 1;
3309 addr->prop.utf8_downcvt = TRUE;
3310 addr->prop.utf8_downcvt_maybe = FALSE;
3316 message_utf8_downconvert = 0;
3317 addr->prop.utf8_downcvt = FALSE;
3318 addr->prop.utf8_downcvt_maybe = FALSE;
3322 if (p[1] == '-' && p[2] == '1')
3324 message_utf8_downconvert = -1;
3325 addr->prop.utf8_downcvt = FALSE;
3326 addr->prop.utf8_downcvt_maybe = TRUE;
3330 *log_msgptr = US"bad option value for control=utf8_downconvert";
3334 message_utf8_downconvert = 1;
3335 addr->prop.utf8_downcvt = TRUE;
3336 addr->prop.utf8_downcvt_maybe = FALSE;
3346 #ifdef EXPERIMENTAL_DCC
3349 /* Separate the regular expression and any optional parameters. */
3350 const uschar * list = arg;
3351 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3352 /* Run the dcc backend. */
3353 rc = dcc_process(&ss);
3354 /* Modify return code based upon the existence of options. */
3355 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3356 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3357 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3362 #ifdef WITH_CONTENT_SCAN
3364 rc = mime_decode(&arg);
3370 int delay = readconf_readtime(arg, 0, FALSE);
3373 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3374 "modifier: \"%s\" is not a time value", arg);
3379 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3384 debug_printf_indent("delay skipped in -bh checking mode\n");
3387 /* NOTE 1: Remember that we may be
3388 dealing with stdin/stdout here, in addition to TCP/IP connections.
3389 Also, delays may be specified for non-SMTP input, where smtp_out and
3390 smtp_in will be NULL. Whatever is done must work in all cases.
3392 NOTE 2: The added feature of flushing the output before a delay must
3393 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3398 if (smtp_out && !f.disable_delay_flush)
3401 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3407 p.fd = fileno(smtp_out);
3408 p.events = POLLRDHUP;
3411 if (poll(&p, n, delay*1000) > 0)
3412 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3415 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3416 TCP/IP connection has gone away without reading from it. This means
3417 that we cannot shorten the delay below if the client goes away,
3418 because we cannot discover that the client has closed its end of the
3419 connection. (The connection is actually in a half-closed state,
3420 waiting for the server to close its end.) It would be nice to be able
3421 to detect this state, so that the Exim process is not held up
3422 unnecessarily. However, it seems that we can't. The poll() function
3423 does not do the right thing, and in any case it is not always
3426 while (delay > 0) delay = sleep(delay);
3433 #ifndef DISABLE_DKIM
3434 case ACLC_DKIM_SIGNER:
3435 if (dkim_cur_signer)
3436 rc = match_isinlist(dkim_cur_signer,
3437 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3442 case ACLC_DKIM_STATUS:
3443 rc = match_isinlist(dkim_verify_status,
3444 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3448 #ifdef SUPPORT_DMARC
3449 case ACLC_DMARC_STATUS:
3450 if (!f.dmarc_has_been_checked)
3452 f.dmarc_has_been_checked = TRUE;
3453 /* used long way of dmarc_exim_expand_query() in case we need more
3454 * view into the process in the future. */
3455 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3456 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3461 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3465 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3466 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3469 /* The value in tls_cipher is the full cipher name, for example,
3470 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3471 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3472 what may in practice come out of the SSL library - which at the time of
3473 writing is poorly documented. */
3475 case ACLC_ENCRYPTED:
3476 if (tls_in.cipher == NULL) rc = FAIL; else
3478 uschar *endcipher = NULL;
3479 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3480 if (!cipher) cipher = tls_in.cipher; else
3482 endcipher = Ustrchr(++cipher, ':');
3483 if (endcipher) *endcipher = 0;
3485 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3486 if (endcipher) *endcipher = ':';
3490 /* Use verify_check_this_host() instead of verify_check_host() so that
3491 we can pass over &host_data to catch any looked up data. Once it has been
3492 set, it retains its value so that it's still there if another ACL verb
3493 comes through here and uses the cache. However, we must put it into
3494 permanent store in case it is also expected to be used in a subsequent
3495 message in the same SMTP connection. */
3498 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3499 sender_host_address ? sender_host_address : US"", CUSS &host_data);
3500 if (rc == DEFER) *log_msgptr = search_error_message;
3501 if (host_data) host_data = string_copy_perm(host_data, TRUE);
3504 case ACLC_LOCAL_PARTS:
3505 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3506 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3507 CUSS &deliver_localpart_data);
3510 case ACLC_LOG_REJECT_TARGET:
3514 const uschar *s = arg;
3516 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3518 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3519 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3520 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3523 logbits |= LOG_MAIN|LOG_REJECT;
3524 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3525 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3528 log_reject_target = logbits;
3535 const uschar *s = arg;
3541 if (Ustrncmp(s, "main", 4) == 0)
3542 { logbits |= LOG_MAIN; s += 4; }
3543 else if (Ustrncmp(s, "panic", 5) == 0)
3544 { logbits |= LOG_PANIC; s += 5; }
3545 else if (Ustrncmp(s, "reject", 6) == 0)
3546 { logbits |= LOG_REJECT; s += 6; }
3549 logbits = LOG_MAIN|LOG_PANIC;
3550 s = string_sprintf(":unknown log name in \"%s\" in "
3551 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3557 while (isspace(*s)) s++;
3559 if (logbits == 0) logbits = LOG_MAIN;
3560 log_write(0, logbits, "%s", string_printing(s));
3564 #ifdef WITH_CONTENT_SCAN
3565 case ACLC_MALWARE: /* Run the malware backend. */
3567 /* Separate the regular expression and any optional parameters. */
3568 const uschar * list = arg;
3569 uschar * ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3571 BOOL defer_ok = FALSE;
3574 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3575 if (strcmpic(opt, US"defer_ok") == 0)
3577 else if ( strncmpic(opt, US"tmo=", 4) == 0
3578 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3581 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3585 rc = malware(ss, timeout);
3586 if (rc == DEFER && defer_ok)
3587 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3591 case ACLC_MIME_REGEX:
3592 rc = mime_regex(&arg);
3597 if (is_tainted(arg))
3599 *log_msgptr = string_sprintf("Tainted name '%s' for queue not permitted",
3603 if (Ustrchr(arg, '/'))
3605 *log_msgptr = string_sprintf(
3606 "Directory separator not permitted in queue name: '%s'", arg);
3609 queue_name = string_copy_perm(arg, FALSE);
3612 case ACLC_RATELIMIT:
3613 rc = acl_ratelimit(arg, where, log_msgptr);
3616 case ACLC_RECIPIENTS:
3617 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3618 CUSS &recipient_data);
3621 #ifdef WITH_CONTENT_SCAN
3627 case ACLC_REMOVE_HEADER:
3628 setup_remove_header(arg);
3631 case ACLC_SENDER_DOMAINS:
3634 sdomain = Ustrrchr(sender_address, '@');
3635 sdomain = sdomain ? sdomain + 1 : US"";
3636 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3637 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3642 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3643 sender_address_cache, -1, 0, CUSS &sender_data);
3646 /* Connection variables must persist forever; message variables not */
3650 int old_pool = store_pool;
3651 if ( cb->u.varname[0] != 'm'
3652 #ifndef DISABLE_EVENT
3653 || event_name /* An event is being delivered */
3656 store_pool = POOL_PERM;
3657 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3658 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3659 dkim_verify_status = string_copy(arg);
3660 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3661 dkim_verify_reason = string_copy(arg);
3664 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3665 store_pool = old_pool;
3669 #ifdef WITH_CONTENT_SCAN
3672 /* Separate the regular expression and any optional parameters. */
3673 const uschar * list = arg;
3674 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3676 rc = spam(CUSS &ss);
3677 /* Modify return code based upon the existence of options. */
3678 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3679 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3680 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3687 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3689 case ACLC_SPF_GUESS:
3690 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3695 rc = acl_udpsend(arg, log_msgptr);
3698 /* If the verb is WARN, discard any user message from verification, because
3699 such messages are SMTP responses, not header additions. The latter come
3700 only from explicit "message" modifiers. However, put the user message into
3701 $acl_verify_message so it can be used in subsequent conditions or modifiers
3702 (until something changes it). */
3705 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3707 acl_verify_message = *user_msgptr;
3708 if (verb == ACL_WARN) *user_msgptr = NULL;
3712 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3713 "condition %d", cb->type);
3717 /* If a condition was negated, invert OK/FAIL. */
3719 if (!conditions[cb->type].is_modifier && cb->u.negated)
3720 if (rc == OK) rc = FAIL;
3721 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3723 if (rc != OK) break; /* Conditions loop */
3727 /* If the result is the one for which "message" and/or "log_message" are used,
3728 handle the values of these modifiers. If there isn't a log message set, we make
3729 it the same as the user message.
3731 "message" is a user message that will be included in an SMTP response. Unless
3732 it is empty, it overrides any previously set user message.
3734 "log_message" is a non-user message, and it adds to any existing non-user
3735 message that is already set.
3737 Most verbs have but a single return for which the messages are relevant, but
3738 for "discard", it's useful to have the log message both when it succeeds and
3739 when it fails. For "accept", the message is used in the OK case if there is no
3740 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3743 if (*epp && rc == OK) user_message = NULL;
3745 if ((BIT(rc) & msgcond[verb]) != 0)
3748 uschar *old_user_msgptr = *user_msgptr;
3749 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3751 /* If the verb is "warn", messages generated by conditions (verification or
3752 nested ACLs) are always discarded. This also happens for acceptance verbs
3753 when they actually do accept. Only messages specified at this level are used.
3754 However, the value of an existing message is available in $acl_verify_message
3755 during expansions. */
3757 if (verb == ACL_WARN ||
3758 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3759 *log_msgptr = *user_msgptr = NULL;
3763 acl_verify_message = old_user_msgptr;
3764 expmessage = expand_string(user_message);
3767 if (!f.expand_string_forcedfail)
3768 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3769 user_message, expand_string_message);
3771 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3776 acl_verify_message = old_log_msgptr;
3777 expmessage = expand_string(log_message);
3780 if (!f.expand_string_forcedfail)
3781 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3782 log_message, expand_string_message);
3784 else if (expmessage[0] != 0)
3786 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3787 string_sprintf("%s: %s", expmessage, *log_msgptr);
3791 /* If no log message, default it to the user message */
3793 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3796 acl_verify_message = NULL;
3804 /*************************************************
3805 * Get line from a literal ACL *
3806 *************************************************/
3808 /* This function is passed to acl_read() in order to extract individual lines
3809 of a literal ACL, which we access via static pointers. We can destroy the
3810 contents because this is called only once (the compiled ACL is remembered).
3812 This code is intended to treat the data in the same way as lines in the main
3813 Exim configuration file. That is:
3815 . Leading spaces are ignored.
3817 . A \ at the end of a line is a continuation - trailing spaces after the \
3818 are permitted (this is because I don't believe in making invisible things
3819 significant). Leading spaces on the continued part of a line are ignored.
3821 . Physical lines starting (significantly) with # are totally ignored, and
3822 may appear within a sequence of backslash-continued lines.
3824 . Blank lines are ignored, but will end a sequence of continuations.
3827 Returns: a pointer to the next line
3831 static uschar *acl_text; /* Current pointer in the text */
3832 static uschar *acl_text_end; /* Points one past the terminating '0' */
3840 /* This loop handles leading blank lines and comments. */
3844 Uskip_whitespace(&acl_text); /* Leading spaces/empty lines */
3845 if (!*acl_text) return NULL; /* No more data */
3846 yield = acl_text; /* Potential data line */
3848 while (*acl_text && *acl_text != '\n') acl_text++;
3850 /* If we hit the end before a newline, we have the whole logical line. If
3851 it's a comment, there's no more data to be given. Otherwise, yield it. */
3853 if (!*acl_text) return *yield == '#' ? NULL : yield;
3855 /* After reaching a newline, end this loop if the physical line does not
3856 start with '#'. If it does, it's a comment, and the loop continues. */
3858 if (*yield != '#') break;
3861 /* This loop handles continuations. We know we have some real data, ending in
3862 newline. See if there is a continuation marker at the end (ignoring trailing
3863 white space). We know that *yield is not white space, so no need to test for
3864 cont > yield in the backwards scanning loop. */
3869 for (cont = acl_text - 1; isspace(*cont); cont--);
3871 /* If no continuation follows, we are done. Mark the end of the line and
3880 /* We have encountered a continuation. Skip over whitespace at the start of
3881 the next line, and indeed the whole of the next line or lines if they are
3886 while (*(++acl_text) == ' ' || *acl_text == '\t');
3887 if (*acl_text != '#') break;
3888 while (*(++acl_text) != 0 && *acl_text != '\n');
3891 /* We have the start of a continuation line. Move all the rest of the data
3892 to join onto the previous line, and then find its end. If the end is not a
3893 newline, we are done. Otherwise loop to look for another continuation. */
3895 memmove(cont, acl_text, acl_text_end - acl_text);
3896 acl_text_end -= acl_text - cont;
3898 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3899 if (*acl_text == 0) return yield;
3902 /* Control does not reach here */
3909 /*************************************************
3910 * Check access using an ACL *
3911 *************************************************/
3913 /* This function is called from address_check. It may recurse via
3914 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3915 passed as a string which is expanded. A forced failure implies no access check
3916 is required. If the result is a single word, it is taken as the name of an ACL
3917 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3918 text, complete with newlines, and parsed as such. In both cases, the ACL check
3919 is then run. This function uses an auxiliary function for acl_read() to call
3920 for reading individual lines of a literal ACL. This is acl_getline(), which
3921 appears immediately above.
3924 where where called from
3925 addr address item when called from RCPT; otherwise NULL
3926 s the input string; NULL is the same as an empty ACL => DENY
3927 user_msgptr where to put a user error (for SMTP response)
3928 log_msgptr where to put a logging message (not for SMTP response)
3930 Returns: OK access is granted
3931 DISCARD access is apparently granted...
3932 FAIL access is denied
3933 FAIL_DROP access is denied; drop the connection
3934 DEFER can't tell at the moment
3939 acl_check_internal(int where, address_item *addr, uschar *s,
3940 uschar **user_msgptr, uschar **log_msgptr)
3943 acl_block *acl = NULL;
3944 uschar *acl_name = US"inline ACL";
3947 /* Catch configuration loops */
3951 *log_msgptr = US"ACL nested too deep: possible loop";
3957 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3961 /* At top level, we expand the incoming string. At lower levels, it has already
3962 been expanded as part of condition processing. */
3966 if (!(ss = expand_string(s)))
3968 if (f.expand_string_forcedfail) return OK;
3969 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3970 expand_string_message);
3976 while (isspace(*ss)) ss++;
3978 /* If we can't find a named ACL, the default is to parse it as an inline one.
3979 (Unless it begins with a slash; non-existent files give rise to an error.) */
3983 /* Handle the case of a string that does not contain any spaces. Look for a
3984 named ACL among those read from the configuration, or a previously read file.
3985 It is possible that the pointer to the ACL is NULL if the configuration
3986 contains a name with no data. If not found, and the text begins with '/',
3987 read an ACL from a file, and save it so it can be re-used. */
3989 if (Ustrchr(ss, ' ') == NULL)
3991 tree_node * t = tree_search(acl_anchor, ss);
3994 if (!(acl = (acl_block *)(t->data.ptr)))
3996 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
3999 acl_name = string_sprintf("ACL \"%s\"", ss);
4000 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4003 else if (*ss == '/')
4005 struct stat statbuf;
4008 log_write(0, LOG_MAIN|LOG_PANIC,
4009 "attempt to open tainted ACL file name \"%s\"", ss);
4010 /* Avoid leaking info to an attacker */
4011 *log_msgptr = US"internal configuration error";
4014 if ((fd = Uopen(ss, O_RDONLY, 0)) < 0)
4016 *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 /* If the string being used as a filename is tainted, so is the file content */
4028 acl_text = store_get(statbuf.st_size + 1, is_tainted(ss));
4029 acl_text_end = acl_text + statbuf.st_size + 1;
4031 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4033 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4034 ss, strerror(errno));
4037 acl_text[statbuf.st_size] = 0;
4040 acl_name = string_sprintf("ACL \"%s\"", ss);
4041 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4045 /* Parse an ACL that is still in text form. If it came from a file, remember it
4046 in the ACL tree, having read it into the POOL_PERM store pool so that it
4047 persists between multiple messages. */
4051 int old_pool = store_pool;
4052 if (fd >= 0) store_pool = POOL_PERM;
4053 acl = acl_read(acl_getline, log_msgptr);
4054 store_pool = old_pool;
4055 if (!acl && *log_msgptr) return ERROR;
4058 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss), is_tainted(ss));
4059 Ustrcpy(t->name, ss);
4061 (void)tree_insertnode(&acl_anchor, t);
4065 /* Now we have an ACL to use. It's possible it may be NULL. */
4070 int basic_errno = 0;
4071 BOOL endpass_seen = FALSE;
4072 BOOL acl_quit_check = acl_level == 0
4073 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4075 *log_msgptr = *user_msgptr = NULL;
4076 f.acl_temp_details = FALSE;
4078 HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n",
4079 verbs[acl->verb], acl->srcfile, acl->srcline);
4081 /* Clear out any search error message from a previous check before testing
4084 search_error_message = NULL;
4085 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4086 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4088 /* Handle special returns: DEFER causes a return except on a WARN verb;
4089 ERROR always causes a return. */
4094 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n",
4095 verbs[acl->verb], acl_name);
4096 if (basic_errno != ERRNO_CALLOUTDEFER)
4098 if (search_error_message != NULL && *search_error_message != 0)
4099 *log_msgptr = search_error_message;
4100 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4103 f.acl_temp_details = TRUE;
4104 if (acl->verb != ACL_WARN) return DEFER;
4107 default: /* Paranoia */
4109 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n",
4110 verbs[acl->verb], acl_name);
4114 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4115 verbs[acl->verb], acl_name);
4119 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n",
4120 verbs[acl->verb], acl_name);
4123 /* DISCARD and DROP can happen only from a nested ACL condition, and
4124 DISCARD can happen only for an "accept" or "discard" verb. */
4127 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4128 verbs[acl->verb], acl_name);
4132 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4133 verbs[acl->verb], acl_name);
4137 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4138 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4139 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4144 if (cond == OK || cond == DISCARD)
4146 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4151 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4159 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4160 if (acl_quit_check) goto badquit;
4161 f.acl_temp_details = TRUE;
4169 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4170 if (acl_quit_check) goto badquit;
4176 if (cond == OK || cond == DISCARD)
4178 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4179 if (acl_quit_check) goto badquit;
4185 debug_printf_indent("discard: endpass encountered - denying access\n");
4193 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4194 if (acl_quit_check) goto badquit;
4202 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4203 if (acl_quit_check) goto badquit;
4210 acl_warn(where, *user_msgptr, *log_msgptr);
4211 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4212 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4213 "condition test deferred%s%s", host_and_ident(TRUE),
4214 (*log_msgptr == NULL)? US"" : US": ",
4215 (*log_msgptr == NULL)? US"" : *log_msgptr);
4216 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4220 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4225 /* Pass to the next ACL item */
4230 /* We have reached the end of the ACL. This is an implicit DENY. */
4232 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4236 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4237 "('%s' verb used incorrectly)", verbs[acl->verb]);
4244 /* Same args as acl_check_internal() above, but the string s is
4245 the name of an ACL followed optionally by up to 9 space-separated arguments.
4246 The name and args are separately expanded. Args go into $acl_arg globals. */
4248 acl_check_wargs(int where, address_item *addr, const uschar *s,
4249 uschar **user_msgptr, uschar **log_msgptr)
4252 uschar * tmp_arg[9]; /* must match acl_arg[] */
4253 uschar * sav_arg[9]; /* must match acl_arg[] */
4259 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4262 for (i = 0; i < 9; i++)
4264 while (*s && isspace(*s)) s++;
4266 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4273 sav_narg = acl_narg;
4275 for (i = 0; i < acl_narg; i++)
4277 sav_arg[i] = acl_arg[i];
4278 acl_arg[i] = tmp_arg[i];
4282 sav_arg[i] = acl_arg[i];
4283 acl_arg[i++] = NULL;
4287 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4290 acl_narg = sav_narg;
4291 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4295 if (f.expand_string_forcedfail) return ERROR;
4296 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4297 tmp, expand_string_message);
4298 return f.search_find_defer ? DEFER : ERROR;
4303 /*************************************************
4304 * Check access using an ACL *
4305 *************************************************/
4307 /* Alternate interface for ACL, used by expansions */
4309 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4312 address_item *addr = NULL;
4315 *user_msgptr = *log_msgptr = NULL;
4316 sender_verified_failed = NULL;
4317 ratelimiters_cmd = NULL;
4318 log_reject_target = LOG_MAIN|LOG_REJECT;
4320 if (where == ACL_WHERE_RCPT)
4322 adb = address_defaults;
4324 addr->address = expand_string(US"$local_part@$domain");
4325 addr->domain = deliver_domain;
4326 addr->local_part = deliver_localpart;
4327 addr->cc_local_part = deliver_localpart;
4328 addr->lc_local_part = deliver_localpart;
4332 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4339 /* This is the external interface for ACL checks. It sets up an address and the
4340 expansions for $domain and $local_part when called after RCPT, then calls
4341 acl_check_internal() to do the actual work.
4344 where ACL_WHERE_xxxx indicating where called from
4345 recipient RCPT address for RCPT check, else NULL
4346 s the input string; NULL is the same as an empty ACL => DENY
4347 user_msgptr where to put a user error (for SMTP response)
4348 log_msgptr where to put a logging message (not for SMTP response)
4350 Returns: OK access is granted by an ACCEPT verb
4351 DISCARD access is granted by a DISCARD verb
4352 FAIL access is denied
4353 FAIL_DROP access is denied; drop the connection
4354 DEFER can't tell at the moment
4357 int acl_where = ACL_WHERE_UNKNOWN;
4360 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4361 uschar **log_msgptr)
4365 address_item *addr = NULL;
4367 *user_msgptr = *log_msgptr = NULL;
4368 sender_verified_failed = NULL;
4369 ratelimiters_cmd = NULL;
4370 log_reject_target = LOG_MAIN|LOG_REJECT;
4372 #ifndef DISABLE_PRDR
4373 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4375 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4378 adb = address_defaults;
4380 addr->address = recipient;
4381 if (deliver_split_address(addr) == DEFER)
4383 *log_msgptr = US"defer in percent_hack_domains check";
4387 if ((addr->prop.utf8_msg = message_smtputf8))
4389 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4390 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4393 deliver_domain = addr->domain;
4394 deliver_localpart = addr->local_part;
4399 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4401 acl_where = ACL_WHERE_UNKNOWN;
4403 /* Cutthrough - if requested,
4404 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4405 and rcpt acl returned accept,
4406 and first recipient (cancel on any subsequents)
4407 open one now and run it up to RCPT acceptance.
4408 A failed verify should cancel cutthrough request,
4409 and will pass the fail to the originator.
4410 Initial implementation: dual-write to spool.
4411 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4413 Cease cutthrough copy on rxd final dot; do not send one.
4415 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4417 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4418 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4419 If temp-reject, close the conn (and keep the spooled copy).
4420 If conn-failure, no action (and keep the spooled copy).
4424 case ACL_WHERE_RCPT:
4425 #ifndef DISABLE_PRDR
4426 case ACL_WHERE_PRDR:
4429 if (f.host_checking_callout) /* -bhc mode */
4430 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4433 && cutthrough.delivery
4434 && rcpt_count > cutthrough.nrcpt
4437 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4438 if (cutthrough.defer_pass)
4440 uschar * s = addr->message;
4441 /* Horrid kludge to recover target's SMTP message */
4443 do --s; while (!isdigit(*s));
4444 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4445 f.acl_temp_details = TRUE;
4449 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4453 else HDEBUG(D_acl) if (cutthrough.delivery)
4454 if (rcpt_count <= cutthrough.nrcpt)
4455 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4457 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4460 case ACL_WHERE_PREDATA:
4462 cutthrough_predata();
4464 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4467 case ACL_WHERE_QUIT:
4468 case ACL_WHERE_NOTQUIT:
4469 /* Drop cutthrough conns, and drop heldopen verify conns if
4470 the previous was not DATA */
4472 uschar prev = smtp_connection_had[smtp_ch_index-2];
4473 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4475 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4483 deliver_domain = deliver_localpart = deliver_address_data =
4484 deliver_domain_data = sender_address_data = NULL;
4486 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4487 ACL, which is really in the middle of an SMTP command. */
4491 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4493 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4494 "ACL", acl_wherenames[where]);
4500 /* A DROP response is not permitted from MAILAUTH */
4502 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4504 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4505 "ACL", acl_wherenames[where]);
4509 /* Before giving a response, take a look at the length of any user message, and
4510 split it up into multiple lines if possible. */
4512 *user_msgptr = string_split_message(*user_msgptr);
4513 if (fake_response != OK)
4514 fake_response_text = string_split_message(fake_response_text);
4520 /*************************************************
4521 * Create ACL variable *
4522 *************************************************/
4524 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4525 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4528 name pointer to the variable's name, starting with c or m
4530 Returns the pointer to variable's tree node
4534 acl_var_create(uschar * name)
4536 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4537 if (!(node = tree_search(*root, name)))
4539 node = store_get(sizeof(tree_node) + Ustrlen(name), is_tainted(name));
4540 Ustrcpy(node->name, name);
4541 (void)tree_insertnode(root, node);
4543 node->data.ptr = NULL;
4549 /*************************************************
4550 * Write an ACL variable in spool format *
4551 *************************************************/
4553 /* This function is used as a callback for tree_walk when writing variables to
4554 the spool file. To retain spool file compatibility, what is written is -aclc or
4555 -aclm followed by the rest of the name and the data length, space separated,
4556 then the value itself, starting on a new line, and terminated by an additional
4557 newline. When we had only numbered ACL variables, the first line might look
4558 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4562 name of the variable
4563 value of the variable
4564 ctx FILE pointer (as a void pointer)
4570 acl_var_write(uschar *name, uschar *value, void *ctx)
4572 FILE *f = (FILE *)ctx;
4573 if (is_tainted(value)) putc('-', f);
4574 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);