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)()) != NULL)
738 BOOL negated = FALSE;
739 uschar *saveline = s;
742 /* Conditions (but not verbs) are allowed to be negated by an initial
745 while (isspace(*s)) s++;
752 /* Read the name of a verb or a condition, or the start of a new ACL, which
753 can be started by a name, or by a macro definition. */
755 s = readconf_readname(name, sizeof(name), s);
756 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
758 /* If a verb is unrecognized, it may be another condition or modifier that
759 continues the previous verb. */
761 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
765 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
777 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
780 this = store_get(sizeof(acl_block), FALSE);
782 lastp = &(this->next);
784 this->condition = NULL;
786 this->srcline = config_lineno; /* for debug output */
787 this->srcfile = config_filename; /**/
788 condp = &(this->condition);
789 if (*s == 0) continue; /* No condition on this line */
795 s = readconf_readname(name, sizeof(name), s); /* Condition name */
798 /* Handle a condition or modifier. */
800 if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0)
802 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
807 /* The modifiers may not be negated */
809 if (negated && conditions[c].is_modifier)
811 *error = string_sprintf("ACL error: negation is not allowed with "
812 "\"%s\"", conditions[c].name);
816 /* ENDPASS may occur only with ACCEPT or DISCARD. */
818 if (c == ACLC_ENDPASS &&
819 this->verb != ACL_ACCEPT &&
820 this->verb != ACL_DISCARD)
822 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
823 conditions[c].name, verbs[this->verb]);
827 cond = store_get(sizeof(acl_condition_block), FALSE);
830 cond->u.negated = negated;
833 condp = &(cond->next);
835 /* The "set" modifier is different in that its argument is "name=value"
836 rather than just a value, and we can check the validity of the name, which
837 gives us a variable name to insert into the data block. The original ACL
838 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
839 extended to 20 of each type, but after that people successfully argued for
840 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
841 After that, we allow alphanumerics and underscores, but the first character
842 after c or m must be a digit or an underscore. This retains backwards
847 if ( Ustrncmp(s, "dkim_verify_status", 18) == 0
848 || Ustrncmp(s, "dkim_verify_reason", 18) == 0)
850 uschar * endptr = s+18;
852 if (isalnum(*endptr))
854 *error = string_sprintf("invalid variable name after \"set\" in ACL "
855 "modifier \"set %s\" "
856 "(only \"dkim_verify_status\" or \"dkim_verify_reason\" permitted)",
860 cond->u.varname = string_copyn(s, 18);
862 while (isspace(*s)) s++;
869 if (Ustrncmp(s, "acl_c", 5) != 0 && Ustrncmp(s, "acl_m", 5) != 0)
871 *error = string_sprintf("invalid variable name after \"set\" in ACL "
872 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
877 if (!isdigit(*endptr) && *endptr != '_')
879 *error = string_sprintf("invalid variable name after \"set\" in ACL "
880 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
885 while (*endptr && *endptr != '=' && !isspace(*endptr))
887 if (!isalnum(*endptr) && *endptr != '_')
889 *error = string_sprintf("invalid character \"%c\" in variable name "
890 "in ACL modifier \"set %s\"", *endptr, s);
896 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
898 while (isspace(*s)) s++;
901 /* For "set", we are now positioned for the data. For the others, only
902 "endpass" has no data */
904 if (c != ACLC_ENDPASS)
908 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
909 conditions[c].is_modifier ? US"modifier" : US"condition");
912 while (isspace(*s)) s++;
913 cond->arg = string_copy(s);
922 /*************************************************
923 * Set up added header line(s) *
924 *************************************************/
926 /* This function is called by the add_header modifier, and also from acl_warn()
927 to implement the now-deprecated way of adding header lines using "message" on a
928 "warn" verb. The argument is treated as a sequence of header lines which are
929 added to a chain, provided there isn't an identical one already there.
931 Argument: string of header lines
936 setup_header(const uschar *hstring)
939 int hlen = Ustrlen(hstring);
941 /* Ignore any leading newlines */
942 while (*hstring == '\n') hstring++, hlen--;
944 /* An empty string does nothing; ensure exactly one final newline. */
945 if (hlen <= 0) return;
946 if (hstring[--hlen] != '\n') /* no newline */
947 q = string_sprintf("%s\n", hstring);
948 else if (hstring[hlen-1] == '\n') /* double newline */
950 uschar * s = string_copy(hstring);
951 while(s[--hlen] == '\n')
958 /* Loop for multiple header lines, taking care about continuations */
960 for (p = q; *p; p = q)
964 int newtype = htype_add_bot;
965 header_line **hptr = &acl_added_headers;
967 /* Find next header line within the string */
971 q = Ustrchr(q, '\n'); /* we know there was a newline */
972 if (*++q != ' ' && *q != '\t') break;
975 /* If the line starts with a colon, interpret the instruction for where to
976 add it. This temporarily sets up a new type. */
980 if (strncmpic(p, US":after_received:", 16) == 0)
982 newtype = htype_add_rec;
985 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
987 newtype = htype_add_rfc;
990 else if (strncmpic(p, US":at_start:", 10) == 0)
992 newtype = htype_add_top;
995 else if (strncmpic(p, US":at_end:", 8) == 0)
997 newtype = htype_add_bot;
1000 while (*p == ' ' || *p == '\t') p++;
1003 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1004 to the front of it. */
1006 for (s = p; s < q - 1; s++)
1007 if (*s == ':' || !isgraph(*s)) break;
1009 hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p);
1010 hlen = Ustrlen(hdr);
1012 /* See if this line has already been added */
1016 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1017 hptr = &(*hptr)->next;
1020 /* Add if not previously present */
1024 /* The header_line struct itself is not tainted, though it points to
1025 possibly tainted data. */
1026 header_line * h = store_get(sizeof(header_line), FALSE);
1039 /*************************************************
1040 * List the added header lines *
1041 *************************************************/
1047 for (header_line * h = acl_added_headers; h; h = h->next)
1050 if (h->text[i-1] == '\n') i--;
1051 g = string_append_listele_n(g, '\n', h->text, i);
1054 return g ? g->s : NULL;
1058 /*************************************************
1059 * Set up removed header line(s) *
1060 *************************************************/
1062 /* This function is called by the remove_header modifier. The argument is
1063 treated as a sequence of header names which are added to a colon separated
1064 list, provided there isn't an identical one already there.
1066 Argument: string of header names
1071 setup_remove_header(const uschar *hnames)
1074 acl_removed_headers = acl_removed_headers
1075 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1076 : string_copy(hnames);
1081 /*************************************************
1083 *************************************************/
1085 /* This function is called when a WARN verb's conditions are true. It adds to
1086 the message's headers, and/or writes information to the log. In each case, this
1087 only happens once (per message for headers, per connection for log).
1089 ** NOTE: The header adding action using the "message" setting is historic, and
1090 its use is now deprecated. The new add_header modifier should be used instead.
1093 where ACL_WHERE_xxxx indicating which ACL this is
1094 user_message message for adding to headers
1095 log_message message for logging, if different
1101 acl_warn(int where, uschar *user_message, uschar *log_message)
1103 if (log_message != NULL && log_message != user_message)
1106 string_item *logged;
1108 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1109 string_printing(log_message));
1111 /* If a sender verification has failed, and the log message is "sender verify
1112 failed", add the failure message. */
1114 if (sender_verified_failed != NULL &&
1115 sender_verified_failed->message != NULL &&
1116 strcmpic(log_message, US"sender verify failed") == 0)
1117 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1119 /* Search previously logged warnings. They are kept in malloc
1120 store so they can be freed at the start of a new message. */
1122 for (logged = acl_warn_logged; logged; logged = logged->next)
1123 if (Ustrcmp(logged->text, text) == 0) break;
1127 int length = Ustrlen(text) + 1;
1128 log_write(0, LOG_MAIN, "%s", text);
1129 logged = store_malloc(sizeof(string_item) + length);
1130 logged->text = US logged + sizeof(string_item);
1131 memcpy(logged->text, text, length);
1132 logged->next = acl_warn_logged;
1133 acl_warn_logged = logged;
1137 /* If there's no user message, we are done. */
1139 if (!user_message) return;
1141 /* If this isn't a message ACL, we can't do anything with a user message.
1144 if (where > ACL_WHERE_NOTSMTP)
1146 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1147 "found in a non-message (%s) ACL: cannot specify header lines here: "
1148 "message ignored", acl_wherenames[where]);
1152 /* The code for setting up header lines is now abstracted into a separate
1153 function so that it can be used for the add_header modifier as well. */
1155 setup_header(user_message);
1160 /*************************************************
1161 * Verify and check reverse DNS *
1162 *************************************************/
1164 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1165 address if this has not yet been done. The host_name_lookup() function checks
1166 that one of these names resolves to an address list that contains the client IP
1167 address, so we don't actually have to do the check here.
1170 user_msgptr pointer for user message
1171 log_msgptr pointer for log message
1173 Returns: OK verification condition succeeded
1174 FAIL verification failed
1175 DEFER there was a problem verifying
1179 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1183 user_msgptr = user_msgptr; /* stop compiler warning */
1185 /* Previous success */
1187 if (sender_host_name != NULL) return OK;
1189 /* Previous failure */
1191 if (host_lookup_failed)
1193 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1197 /* Need to do a lookup */
1200 debug_printf_indent("looking up host name to force name/address consistency check\n");
1202 if ((rc = host_name_lookup()) != OK)
1204 *log_msgptr = rc == DEFER
1205 ? US"host lookup deferred for reverse lookup check"
1206 : string_sprintf("host lookup failed for reverse lookup check%s",
1208 return rc; /* DEFER or FAIL */
1211 host_build_sender_fullhost();
1217 /*************************************************
1218 * Check client IP address matches CSA target *
1219 *************************************************/
1221 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1222 response for address records belonging to the CSA target hostname. The section
1223 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1224 If one of the addresses matches the client's IP address, then the client is
1225 authorized by CSA. If there are target IP addresses but none of them match
1226 then the client is using an unauthorized IP address. If there are no target IP
1227 addresses then the client cannot be using an authorized IP address. (This is
1228 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1231 dnsa the DNS answer block
1232 dnss a DNS scan block for us to use
1233 reset option specifying what portion to scan, as described above
1234 target the target hostname to use for matching RR names
1236 Returns: CSA_OK successfully authorized
1237 CSA_FAIL_MISMATCH addresses found but none matched
1238 CSA_FAIL_NOADDR no target addresses found
1242 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1245 int rc = CSA_FAIL_NOADDR;
1247 for (dns_record * rr = dns_next_rr(dnsa, dnss, reset);
1249 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1251 /* Check this is an address RR for the target hostname. */
1255 && rr->type != T_AAAA
1259 if (strcmpic(target, rr->name) != 0) continue;
1261 rc = CSA_FAIL_MISMATCH;
1263 /* Turn the target address RR into a list of textual IP addresses and scan
1264 the list. There may be more than one if it is an A6 RR. */
1266 for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next)
1268 /* If the client IP address matches the target IP address, it's good! */
1270 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1272 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1276 /* If we found some target addresses but none of them matched, the client is
1277 using an unauthorized IP address, otherwise the target has no authorized IP
1285 /*************************************************
1286 * Verify Client SMTP Authorization *
1287 *************************************************/
1289 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1290 to find the CSA SRV record corresponding to the domain argument, or
1291 $sender_helo_name if no argument is provided. It then checks that the
1292 client is authorized, and that its IP address corresponds to the SRV
1293 target's address by calling acl_verify_csa_address() above. The address
1294 should have been returned in the DNS response's ADDITIONAL section, but if
1295 not we perform another DNS lookup to get it.
1298 domain pointer to optional parameter following verify = csa
1300 Returns: CSA_UNKNOWN no valid CSA record found
1301 CSA_OK successfully authorized
1302 CSA_FAIL_* client is definitely not authorized
1303 CSA_DEFER_* there was a DNS problem
1307 acl_verify_csa(const uschar *domain)
1310 const uschar *found;
1311 int priority, weight, port;
1312 dns_answer * dnsa = store_get_dns_answer();
1318 /* Work out the domain we are using for the CSA lookup. The default is the
1319 client's HELO domain. If the client has not said HELO, use its IP address
1320 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1322 while (isspace(*domain) && *domain != '\0') ++domain;
1323 if (*domain == '\0') domain = sender_helo_name;
1324 if (domain == NULL) domain = sender_host_address;
1325 if (sender_host_address == NULL) return CSA_UNKNOWN;
1327 /* If we have an address literal, strip off the framing ready for turning it
1328 into a domain. The framing consists of matched square brackets possibly
1329 containing a keyword and a colon before the actual IP address. */
1331 if (domain[0] == '[')
1333 const uschar *start = Ustrchr(domain, ':');
1334 if (start == NULL) start = domain;
1335 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1338 /* Turn domains that look like bare IP addresses into domains in the reverse
1339 DNS. This code also deals with address literals and $sender_host_address. It's
1340 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1341 address literals, but it's probably the most friendly thing to do. This is an
1342 extension to CSA, so we allow it to be turned off for proper conformance. */
1344 if (string_is_ip_address(domain, NULL) != 0)
1346 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1347 domain = dns_build_reverse(domain);
1350 /* Find out if we've already done the CSA check for this domain. If we have,
1351 return the same result again. Otherwise build a new cached result structure
1352 for this domain. The name is filled in now, and the value is filled in when
1353 we return from this function. */
1355 t = tree_search(csa_cache, domain);
1356 if (t != NULL) return t->data.val;
1358 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain), is_tainted(domain));
1359 Ustrcpy(t->name, domain);
1360 (void)tree_insertnode(&csa_cache, t);
1362 /* Now we are ready to do the actual DNS lookup(s). */
1365 switch (dns_special_lookup(dnsa, domain, T_CSA, &found))
1367 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1370 return t->data.val = CSA_DEFER_SRV;
1372 /* If we found nothing, the client's authorization is unknown. */
1376 return t->data.val = CSA_UNKNOWN;
1378 /* We got something! Go on to look at the reply in more detail. */
1384 /* Scan the reply for well-formed CSA SRV records. */
1386 for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1388 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1390 const uschar * p = rr->data;
1392 /* Extract the numerical SRV fields (p is incremented) */
1394 GETSHORT(priority, p);
1395 GETSHORT(weight, p);
1399 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1401 /* Check the CSA version number */
1403 if (priority != 1) continue;
1405 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1406 found by dns_special_lookup() is a parent of the one we asked for), we check
1407 the subdomain assertions in the port field. At the moment there's only one
1408 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1409 SRV records of their own. */
1411 if (Ustrcmp(found, domain) != 0)
1412 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1414 /* This CSA SRV record refers directly to our domain, so we check the value
1415 in the weight field to work out the domain's authorization. 0 and 1 are
1416 unauthorized; 3 means the client is authorized but we can't check the IP
1417 address in order to authenticate it, so we treat it as unknown; values
1418 greater than 3 are undefined. */
1420 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1422 if (weight > 2) continue;
1424 /* Weight == 2, which means the domain is authorized. We must check that the
1425 client's IP address is listed as one of the SRV target addresses. Save the
1426 target hostname then break to scan the additional data for its addresses. */
1428 (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, p,
1429 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1431 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1436 /* If we didn't break the loop then no appropriate records were found. */
1438 if (!rr) return t->data.val = CSA_UNKNOWN;
1440 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1441 A target of "." indicates there are no valid addresses, so the client cannot
1442 be authorized. (This is an odd configuration because weight=2 target=. is
1443 equivalent to weight=1, but we check for it in order to keep load off the
1444 root name servers.) Note that dn_expand() turns "." into "". */
1446 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1448 /* Scan the additional section of the CSA SRV reply for addresses belonging
1449 to the target. If the name server didn't return any additional data (e.g.
1450 because it does not fully support SRV records), we need to do another lookup
1451 to obtain the target addresses; otherwise we have a definitive result. */
1453 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ADDITIONAL, target);
1454 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1456 /* The DNS lookup type corresponds to the IP version used by the client. */
1459 if (Ustrchr(sender_host_address, ':') != NULL)
1462 #endif /* HAVE_IPV6 */
1466 lookup_dnssec_authenticated = NULL;
1467 switch (dns_lookup(dnsa, target, type, NULL))
1469 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1472 return t->data.val = CSA_DEFER_ADDR;
1474 /* If the query succeeded, scan the addresses and return the result. */
1477 rc = acl_verify_csa_address(dnsa, &dnss, RESET_ANSWERS, target);
1478 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1479 /* else fall through */
1481 /* If the target has no IP addresses, the client cannot have an authorized
1482 IP address. However, if the target site uses A6 records (not AAAA records)
1483 we have to do yet another lookup in order to check them. */
1487 return t->data.val = CSA_FAIL_NOADDR;
1493 /*************************************************
1494 * Handle verification (address & other) *
1495 *************************************************/
1497 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1498 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1499 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1504 unsigned where_allowed; /* bitmap */
1505 BOOL no_options; /* Never has /option(s) following */
1506 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1508 static verify_type_t verify_type_list[] = {
1509 /* name value where no-opt opt-sep */
1510 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, (unsigned)~0, FALSE, 0 },
1511 { US"certificate", VERIFY_CERT, (unsigned)~0, TRUE, 0 },
1512 { US"helo", VERIFY_HELO, (unsigned)~0, TRUE, 0 },
1513 { US"csa", VERIFY_CSA, (unsigned)~0, FALSE, 0 },
1514 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1515 { US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1516 { US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1517 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1518 |ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1520 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1521 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1522 #ifdef EXPERIMENTAL_ARC
1523 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1528 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1529 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1530 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1531 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1537 BOOL has_option; /* Has =option(s) following */
1538 BOOL timeval; /* Has a time value */
1540 static callout_opt_t callout_opt_list[] = {
1541 /* name value flag has-opt has-time */
1542 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1543 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1544 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1545 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1546 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1547 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1548 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1549 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1550 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1551 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1552 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1553 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1554 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1559 /* This function implements the "verify" condition. It is called when
1560 encountered in any ACL, because some tests are almost always permitted. Some
1561 just don't make sense, and always fail (for example, an attempt to test a host
1562 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1565 where where called from
1566 addr the recipient address that the ACL is handling, or NULL
1567 arg the argument of "verify"
1568 user_msgptr pointer for user message
1569 log_msgptr pointer for log message
1570 basic_errno where to put verify errno
1572 Returns: OK verification condition succeeded
1573 FAIL verification failed
1574 DEFER there was a problem verifying
1579 acl_verify(int where, address_item *addr, const uschar *arg,
1580 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1584 int callout_overall = -1;
1585 int callout_connect = -1;
1586 int verify_options = 0;
1588 BOOL verify_header_sender = FALSE;
1589 BOOL defer_ok = FALSE;
1590 BOOL callout_defer_ok = FALSE;
1591 BOOL no_details = FALSE;
1592 BOOL success_on_redirect = FALSE;
1593 address_item *sender_vaddr = NULL;
1594 uschar *verify_sender_address = NULL;
1595 uschar *pm_mailfrom = NULL;
1596 uschar *se_mailfrom = NULL;
1598 /* Some of the verify items have slash-separated options; some do not. Diagnose
1599 an error if options are given for items that don't expect them.
1602 uschar *slash = Ustrchr(arg, '/');
1603 const uschar *list = arg;
1604 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1607 if (!ss) goto BAD_VERIFY;
1609 /* Handle name/address consistency verification in a separate function. */
1611 for (vp = verify_type_list;
1612 CS vp < CS verify_type_list + sizeof(verify_type_list);
1615 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1616 : strcmpic (ss, vp->name) == 0)
1618 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1621 if (vp->no_options && slash)
1623 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1624 "(this verify item has no options)", arg);
1627 if (!(vp->where_allowed & BIT(where)))
1629 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1630 vp->name, acl_wherenames[where]);
1635 case VERIFY_REV_HOST_LKUP:
1636 if (!sender_host_address) return OK;
1637 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1638 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1639 if (strcmpic(ss, US"defer_ok") == 0)
1644 /* TLS certificate verification is done at STARTTLS time; here we just
1645 test whether it was successful or not. (This is for optional verification; for
1646 mandatory verification, the connection doesn't last this long.) */
1648 if (tls_in.certificate_verified) return OK;
1649 *user_msgptr = US"no verified certificate";
1653 /* We can test the result of optional HELO verification that might have
1654 occurred earlier. If not, we can attempt the verification now. */
1656 if (!f.helo_verified && !f.helo_verify_failed) smtp_verify_helo();
1657 return f.helo_verified ? OK : FAIL;
1660 /* Do Client SMTP Authorization checks in a separate function, and turn the
1661 result code into user-friendly strings. */
1663 rc = acl_verify_csa(list);
1664 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1665 csa_reason_string[rc]);
1666 csa_status = csa_status_string[rc];
1667 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1668 return csa_return_code[rc];
1670 #ifdef EXPERIMENTAL_ARC
1672 { /* Do Authenticated Received Chain checks in a separate function. */
1673 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1677 if (!(arc_state = acl_verify_arc())) return DEFER;
1678 DEBUG(D_acl) debug_printf_indent("ARC verify result %s %s%s%s\n", arc_state,
1679 arc_state_reason ? "(":"", arc_state_reason, arc_state_reason ? ")":"");
1681 if (!condlist) condlist = US"none:pass";
1682 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1683 if (Ustrcmp(arc_state, cond) == 0) return OK;
1688 case VERIFY_HDR_SYNTAX:
1689 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1690 a syntax error, we return details of the error to the sender if configured to
1691 send out full details. (But a "message" setting on the ACL can override, as
1694 rc = verify_check_headers(log_msgptr);
1695 if (rc != OK && *log_msgptr)
1696 if (smtp_return_error_details)
1697 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1699 acl_verify_message = *log_msgptr;
1702 case VERIFY_HDR_NAMES_ASCII:
1703 /* Check that all header names are true 7 bit strings
1704 See RFC 5322, 2.2. and RFC 6532, 3. */
1706 rc = verify_check_header_names_ascii(log_msgptr);
1707 if (rc != OK && smtp_return_error_details && *log_msgptr)
1708 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1711 case VERIFY_NOT_BLIND:
1712 /* Check that no recipient of this message is "blind", that is, every envelope
1713 recipient must be mentioned in either To: or Cc:. */
1715 BOOL case_sensitive = TRUE;
1717 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1718 if (strcmpic(ss, US"case_insensitive") == 0)
1719 case_sensitive = FALSE;
1722 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1723 "condition \"verify %s\"", ss, arg);
1727 if ((rc = verify_check_notblind(case_sensitive)) != OK)
1729 *log_msgptr = US"bcc recipient detected";
1730 if (smtp_return_error_details)
1731 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1736 /* The remaining verification tests check recipient and sender addresses,
1737 either from the envelope or from the header. There are a number of
1738 slash-separated options that are common to all of them. */
1740 case VERIFY_HDR_SNDR:
1741 verify_header_sender = TRUE;
1745 /* In the case of a sender, this can optionally be followed by an address to use
1746 in place of the actual sender (rare special-case requirement). */
1750 verify_sender_address = sender_address;
1753 while (isspace(*s)) s++;
1754 if (*s++ != '=') goto BAD_VERIFY;
1755 while (isspace(*s)) s++;
1756 verify_sender_address = string_copy(s);
1767 /* Remaining items are optional; they apply to sender and recipient
1768 verification, including "header sender" verification. */
1770 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1772 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1773 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1774 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1776 /* These two old options are left for backwards compatibility */
1778 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1780 callout_defer_ok = TRUE;
1781 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1784 else if (strcmpic(ss, US"check_postmaster") == 0)
1787 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1790 /* The callout option has a number of sub-options, comma separated */
1792 else if (strncmpic(ss, US"callout", 7) == 0)
1794 callout = CALLOUT_TIMEOUT_DEFAULT;
1798 while (isspace(*ss)) ss++;
1801 const uschar * sublist = ss;
1806 while (isspace(*sublist)) sublist++;
1807 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1810 double period = 1.0F;
1812 for (op= callout_opt_list; op->name; op++)
1813 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1816 verify_options |= op->flag;
1819 opt += Ustrlen(op->name);
1820 while (isspace(*opt)) opt++;
1823 *log_msgptr = string_sprintf("'=' expected after "
1824 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1827 while (isspace(*opt)) opt++;
1829 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1831 *log_msgptr = string_sprintf("bad time value in ACL condition "
1832 "\"verify %s\"", arg);
1838 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1839 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1840 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1841 case CALLOUT_MAILFROM:
1842 if (!verify_header_sender)
1844 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1845 "callout option only for verify=header_sender (detected in ACL "
1846 "condition \"%s\")", arg);
1849 se_mailfrom = string_copy(opt);
1851 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1852 case CALLOUT_MAXWAIT: callout_overall = period; break;
1853 case CALLOUT_CONNECT: callout_connect = period; break;
1854 case CALLOUT_TIME: callout = period; break;
1860 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1861 "ACL condition \"%s\"", arg);
1867 /* Option not recognized */
1871 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1872 "condition \"verify %s\"", ss, arg);
1877 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1878 (vopt_callout_recipsender|vopt_callout_recippmaster))
1880 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1881 "for a recipient callout";
1885 /* Handle sender-in-header verification. Default the user message to the log
1886 message if giving out verification details. */
1888 if (verify_header_sender)
1892 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1893 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1896 *basic_errno = verrno;
1897 if (smtp_return_error_details)
1899 if (!*user_msgptr && *log_msgptr)
1900 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1901 if (rc == DEFER) f.acl_temp_details = TRUE;
1906 /* Handle a sender address. The default is to verify *the* sender address, but
1907 optionally a different address can be given, for special requirements. If the
1908 address is empty, we are dealing with a bounce message that has no sender, so
1909 we cannot do any checking. If the real sender address gets rewritten during
1910 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1911 during message reception.
1913 A list of verified "sender" addresses is kept to try to avoid doing to much
1914 work repetitively when there are multiple recipients in a message and they all
1915 require sender verification. However, when callouts are involved, it gets too
1916 complicated because different recipients may require different callout options.
1917 Therefore, we always do a full sender verify when any kind of callout is
1918 specified. Caching elsewhere, for instance in the DNS resolver and in the
1919 callout handling, should ensure that this is not terribly inefficient. */
1921 else if (verify_sender_address)
1923 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1925 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1926 "sender verify callout";
1930 sender_vaddr = verify_checked_sender(verify_sender_address);
1931 if (sender_vaddr != NULL && /* Previously checked */
1932 callout <= 0) /* No callout needed this time */
1934 /* If the "routed" flag is set, it means that routing worked before, so
1935 this check can give OK (the saved return code value, if set, belongs to a
1936 callout that was done previously). If the "routed" flag is not set, routing
1937 must have failed, so we use the saved return code. */
1939 if (testflag(sender_vaddr, af_verify_routed))
1943 rc = sender_vaddr->special_action;
1944 *basic_errno = sender_vaddr->basic_errno;
1946 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1949 /* Do a new verification, and cache the result. The cache is used to avoid
1950 verifying the sender multiple times for multiple RCPTs when callouts are not
1951 specified (see comments above).
1953 The cache is also used on failure to give details in response to the first
1954 RCPT that gets bounced for this reason. However, this can be suppressed by
1955 the no_details option, which sets the flag that says "this detail has already
1956 been sent". The cache normally contains just one address, but there may be
1957 more in esoteric circumstances. */
1962 uschar *save_address_data = deliver_address_data;
1964 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1966 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1968 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1969 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1972 if (no_details) setflag(sender_vaddr, af_sverify_told);
1973 if (verify_sender_address[0] != 0)
1975 /* If this is the real sender address, save the unrewritten version
1976 for use later in receive. Otherwise, set a flag so that rewriting the
1977 sender in verify_address() does not update sender_address. */
1979 if (verify_sender_address == sender_address)
1980 sender_address_unrewritten = sender_address;
1982 verify_options |= vopt_fake_sender;
1984 if (success_on_redirect)
1985 verify_options |= vopt_success_on_redirect;
1987 /* The recipient, qualify, and expn options are never set in
1990 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1991 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1993 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
1996 *basic_errno = sender_vaddr->basic_errno;
2000 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2001 debug_printf_indent("sender %s verified ok as %s\n",
2002 verify_sender_address, sender_vaddr->address);
2004 debug_printf_indent("sender %s verified ok\n",
2005 verify_sender_address);
2009 rc = OK; /* Null sender */
2011 /* Cache the result code */
2013 if (routed) setflag(sender_vaddr, af_verify_routed);
2014 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2015 sender_vaddr->special_action = rc;
2016 sender_vaddr->next = sender_verified_list;
2017 sender_verified_list = sender_vaddr;
2019 /* Restore the recipient address data, which might have been clobbered by
2020 the sender verification. */
2022 deliver_address_data = save_address_data;
2025 /* Put the sender address_data value into $sender_address_data */
2027 sender_address_data = sender_vaddr->prop.address_data;
2030 /* A recipient address just gets a straightforward verify; again we must handle
2031 the DEFER overrides. */
2037 if (success_on_redirect)
2038 verify_options |= vopt_success_on_redirect;
2040 /* We must use a copy of the address for verification, because it might
2044 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2045 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2046 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2048 *basic_errno = addr2.basic_errno;
2049 *log_msgptr = addr2.message;
2050 *user_msgptr = (addr2.user_message != NULL)?
2051 addr2.user_message : addr2.message;
2053 /* Allow details for temporary error if the address is so flagged. */
2054 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2056 /* Make $address_data visible */
2057 deliver_address_data = addr2.prop.address_data;
2060 /* We have a result from the relevant test. Handle defer overrides first. */
2062 if (rc == DEFER && (defer_ok ||
2063 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2065 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2066 defer_ok? "defer_ok" : "callout_defer_ok");
2070 /* If we've failed a sender, set up a recipient message, and point
2071 sender_verified_failed to the address item that actually failed. */
2073 if (rc != OK && verify_sender_address != NULL)
2076 *log_msgptr = *user_msgptr = US"Sender verify failed";
2077 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2078 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2081 *log_msgptr = US"Could not complete sender verify callout";
2082 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2086 sender_verified_failed = sender_vaddr;
2089 /* Verifying an address messes up the values of $domain and $local_part,
2090 so reset them before returning if this is a RCPT ACL. */
2094 deliver_domain = addr->domain;
2095 deliver_localpart = addr->local_part;
2099 /* Syntax errors in the verify argument come here. */
2102 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2103 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2104 "or \"reverse_host_lookup\" at start of ACL condition "
2105 "\"verify %s\"", arg);
2112 /*************************************************
2113 * Check argument for control= modifier *
2114 *************************************************/
2116 /* Called from acl_check_condition() below.
2117 To handle the case "queue_only" we accept an _ in the
2118 initial / option-switch position.
2121 arg the argument string for control=
2122 pptr set to point to the terminating character
2123 where which ACL we are in
2124 log_msgptr for error messages
2126 Returns: CONTROL_xxx value
2130 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2136 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2137 || ( (c = arg[len = Ustrlen((d = controls_list+idx)->name)]) != 0
2138 && (!d->has_option || c != '/' && c != '_')
2141 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2142 return CONTROL_ERROR;
2152 /*************************************************
2153 * Return a ratelimit error *
2154 *************************************************/
2156 /* Called from acl_ratelimit() below
2159 log_msgptr for error messages
2160 format format string
2161 ... supplementary arguments
2167 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2171 string_cat(NULL, US"error in arguments to \"ratelimit\" condition: ");
2173 va_start(ap, format);
2174 g = string_vformat(g, SVFMT_EXTEND|SVFMT_REBUFFER, format, ap);
2177 gstring_release_unused(g);
2178 *log_msgptr = string_from_gstring(g);
2185 /*************************************************
2186 * Handle rate limiting *
2187 *************************************************/
2189 /* Called by acl_check_condition() below to calculate the result
2190 of the ACL ratelimit condition.
2192 Note that the return value might be slightly unexpected: if the
2193 sender's rate is above the limit then the result is OK. This is
2194 similar to the dnslists condition, and is so that you can write
2195 ACL clauses like: defer ratelimit = 15 / 1h
2198 arg the option string for ratelimit=
2199 where ACL_WHERE_xxxx indicating which ACL this is
2200 log_msgptr for error messages
2202 Returns: OK - Sender's rate is above limit
2203 FAIL - Sender's rate is below limit
2204 DEFER - Problem opening ratelimit database
2205 ERROR - Syntax error in options.
2209 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2211 double limit, period, count;
2214 uschar *unique = NULL;
2216 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2217 BOOL noupdate = FALSE, badacl = FALSE;
2218 int mode = RATE_PER_WHAT;
2220 tree_node **anchor, *t;
2221 open_db dbblock, *dbm;
2223 dbdata_ratelimit *dbd;
2224 dbdata_ratelimit_unique *dbdb;
2227 /* Parse the first two options and record their values in expansion
2228 variables. These variables allow the configuration to have informative
2229 error messages based on rate limits obtained from a table lookup. */
2231 /* First is the maximum number of messages per period / maximum burst
2232 size, which must be greater than or equal to zero. Zero is useful for
2233 rate measurement as opposed to rate limiting. */
2235 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2236 return ratelimit_error(log_msgptr, "sender rate limit not set");
2238 limit = Ustrtod(sender_rate_limit, &ss);
2239 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2240 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2241 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2243 if (limit < 0.0 || *ss != '\0')
2244 return ratelimit_error(log_msgptr,
2245 "\"%s\" is not a positive number", sender_rate_limit);
2247 /* Second is the rate measurement period / exponential smoothing time
2248 constant. This must be strictly greater than zero, because zero leads to
2249 run-time division errors. */
2251 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2252 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2254 return ratelimit_error(log_msgptr,
2255 "\"%s\" is not a time value", sender_rate_period);
2257 /* By default we are counting one of something, but the per_rcpt,
2258 per_byte, and count options can change this. */
2262 /* Parse the other options. */
2264 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)))
2266 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2267 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2268 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2269 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2270 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2271 else if (strcmpic(ss, US"per_conn") == 0)
2273 RATE_SET(mode, PER_CONN);
2274 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2277 else if (strcmpic(ss, US"per_mail") == 0)
2279 RATE_SET(mode, PER_MAIL);
2280 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2282 else if (strcmpic(ss, US"per_rcpt") == 0)
2284 /* If we are running in the RCPT ACL, then we'll count the recipients
2285 one by one, but if we are running when we have accumulated the whole
2286 list then we'll add them all in one batch. */
2287 if (where == ACL_WHERE_RCPT)
2288 RATE_SET(mode, PER_RCPT);
2289 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2290 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2291 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2292 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2294 else if (strcmpic(ss, US"per_byte") == 0)
2296 /* If we have not yet received the message data and there was no SIZE
2297 declaration on the MAIL command, then it's safe to just use a value of
2298 zero and let the recorded rate decay as if nothing happened. */
2299 RATE_SET(mode, PER_MAIL);
2300 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2301 else count = message_size < 0 ? 0.0 : (double)message_size;
2303 else if (strcmpic(ss, US"per_addr") == 0)
2305 RATE_SET(mode, PER_RCPT);
2306 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2307 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2309 else if (strncmpic(ss, US"count=", 6) == 0)
2312 count = Ustrtod(ss+6, &e);
2313 if (count < 0.0 || *e != '\0')
2314 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2316 else if (strncmpic(ss, US"unique=", 7) == 0)
2317 unique = string_copy(ss + 7);
2319 key = string_copy(ss);
2321 key = string_sprintf("%s/%s", key, ss);
2324 /* Sanity check. When the badacl flag is set the update mode must either
2325 be readonly (which is the default if it is omitted) or, for backwards
2326 compatibility, a combination of noupdate and strict or leaky. */
2328 if (mode == RATE_PER_CLASH)
2329 return ratelimit_error(log_msgptr, "conflicting per_* options");
2330 if (leaky + strict + readonly > 1)
2331 return ratelimit_error(log_msgptr, "conflicting update modes");
2332 if (badacl && (leaky || strict) && !noupdate)
2333 return ratelimit_error(log_msgptr,
2334 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2335 ratelimit_option_string[mode], acl_wherenames[where]);
2337 /* Set the default values of any unset options. In readonly mode we
2338 perform the rate computation without any increment so that its value
2339 decays to eventually allow over-limit senders through. */
2341 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2342 if (badacl) readonly = TRUE;
2343 if (readonly) count = 0.0;
2344 if (!strict && !readonly) leaky = TRUE;
2345 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2347 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2348 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2349 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2350 are added to the key because they alter the meaning of the stored data. */
2353 key = !sender_host_address ? US"" : sender_host_address;
2355 key = string_sprintf("%s/%s/%s%s",
2357 ratelimit_option_string[mode],
2358 unique == NULL ? "" : "unique/",
2362 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2364 /* See if we have already computed the rate by looking in the relevant tree.
2365 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2366 pool so that they survive across resets. In readonly mode we only remember the
2367 result for the rest of this command in case a later command changes it. After
2368 this bit of logic the code is independent of the per_* mode. */
2370 old_pool = store_pool;
2373 anchor = &ratelimiters_cmd;
2377 anchor = &ratelimiters_conn;
2378 store_pool = POOL_PERM;
2382 case RATE_PER_ALLRCPTS:
2383 anchor = &ratelimiters_mail;
2388 anchor = &ratelimiters_cmd;
2391 anchor = NULL; /* silence an "unused" complaint */
2392 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2393 "internal ACL error: unknown ratelimit mode %d", mode);
2397 if ((t = tree_search(*anchor, key)))
2400 /* The following few lines duplicate some of the code below. */
2401 rc = (dbd->rate < limit)? FAIL : OK;
2402 store_pool = old_pool;
2403 sender_rate = string_sprintf("%.1f", dbd->rate);
2405 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2409 /* We aren't using a pre-computed rate, so get a previously recorded rate
2410 from the database, which will be updated and written back if required. */
2412 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE, TRUE)))
2414 store_pool = old_pool;
2416 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2417 *log_msgptr = US"ratelimit database not available";
2420 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2423 gettimeofday(&tv, NULL);
2427 /* Locate the basic ratelimit block inside the DB data. */
2428 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2431 /* Forget the old Bloom filter if it is too old, so that we count each
2432 repeating event once per period. We don't simply clear and re-use the old
2433 filter because we want its size to change if the limit changes. Note that
2434 we keep the dbd pointer for copying the rate into the new data block. */
2436 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2438 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2444 if(unique && dbdb_size < sizeof(*dbdb))
2446 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2451 /* Allocate a new data block if the database lookup failed
2452 or the Bloom filter passed its age limit. */
2458 /* No Bloom filter. This basic ratelimit block is initialized below. */
2459 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2460 dbdb_size = sizeof(*dbd);
2461 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2466 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2468 /* See the long comment below for an explanation of the magic number 2.
2469 The filter has a minimum size in case the rate limit is very small;
2470 this is determined by the definition of dbdata_ratelimit_unique. */
2472 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2473 if (extra < 0) extra = 0;
2474 dbdb_size = sizeof(*dbdb) + extra;
2475 dbdb = store_get(dbdb_size, FALSE); /* not tainted */
2476 dbdb->bloom_epoch = tv.tv_sec;
2477 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2478 memset(dbdb->bloom, 0, dbdb->bloom_size);
2480 /* Preserve any basic ratelimit data (which is our longer-term memory)
2481 by copying it from the discarded block. */
2491 /* If we are counting unique events, find out if this event is new or not.
2492 If the client repeats the event during the current period then it should be
2493 counted. We skip this code in readonly mode for efficiency, because any
2494 changes to the filter will be discarded and because count is already set to
2497 if (unique && !readonly)
2499 /* We identify unique events using a Bloom filter. (You can find my
2500 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2501 With the per_addr option, an "event" is a recipient address, though the
2502 user can use the unique option to define their own events. We only count
2503 an event if we have not seen it before.
2505 We size the filter according to the rate limit, which (in leaky mode)
2506 is the limit on the population of the filter. We allow 16 bits of space
2507 per entry (see the construction code above) and we set (up to) 8 of them
2508 when inserting an element (see the loop below). The probability of a false
2509 positive (an event we have not seen before but which we fail to count) is
2513 allzero = exp(-numhash * pop / size)
2514 = exp(-0.5 * pop / limit)
2515 fpr = pow(1 - allzero, numhash)
2517 For senders at the limit the fpr is 0.06% or 1 in 1700
2518 and for senders at half the limit it is 0.0006% or 1 in 170000
2520 In strict mode the Bloom filter can fill up beyond the normal limit, in
2521 which case the false positive rate will rise. This means that the
2522 measured rate for very fast senders can bogusly drop off after a while.
2524 At twice the limit, the fpr is 2.5% or 1 in 40
2525 At four times the limit, it is 31% or 1 in 3.2
2527 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2528 decay below the limit, and if this is more than one then the Bloom filter
2529 will be discarded before the decay gets that far. The false positive rate
2530 at this threshold is 9.3% or 1 in 10.7. */
2533 unsigned n, hash, hinc;
2537 /* Instead of using eight independent hash values, we combine two values
2538 using the formula h1 + n * h2. This does not harm the Bloom filter's
2539 performance, and means the amount of hash we need is independent of the
2540 number of bits we set in the filter. */
2542 md5_start(&md5info);
2543 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2544 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2545 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2547 /* Scan the bits corresponding to this event. A zero bit means we have
2548 not seen it before. Ensure all bits are set to record this event. */
2550 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2553 for (n = 0; n < 8; n++, hash += hinc)
2555 int bit = 1 << (hash % 8);
2556 int byte = (hash / 8) % dbdb->bloom_size;
2557 if ((dbdb->bloom[byte] & bit) == 0)
2559 dbdb->bloom[byte] |= bit;
2564 /* If this event has occurred before, do not count it. */
2568 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2572 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2575 /* If there was no previous ratelimit data block for this key, initialize
2576 the new one, otherwise update the block from the database. The initial rate
2577 is what would be computed by the code below for an infinite interval. */
2581 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2583 dbd->time_stamp = tv.tv_sec;
2584 dbd->time_usec = tv.tv_usec;
2589 /* The smoothed rate is computed using an exponentially weighted moving
2590 average adjusted for variable sampling intervals. The standard EWMA for
2591 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2592 where f() is the measured value and f'() is the smoothed value.
2594 Old data decays out of the smoothed value exponentially, such that data n
2595 samples old is multiplied by a^n. The exponential decay time constant p
2596 is defined such that data p samples old is multiplied by 1/e, which means
2597 that a = exp(-1/p). We can maintain the same time constant for a variable
2598 sampling interval i by using a = exp(-i/p).
2600 The rate we are measuring is messages per period, suitable for directly
2601 comparing with the limit. The average rate between now and the previous
2602 message is period / interval, which we feed into the EWMA as the sample.
2604 It turns out that the number of messages required for the smoothed rate
2605 to reach the limit when they are sent in a burst is equal to the limit.
2606 This can be seen by analysing the value of the smoothed rate after N
2607 messages sent at even intervals. Let k = (1 - a) * p/i
2609 rate_1 = (1 - a) * p/i + a * rate_0
2611 rate_2 = k + a * rate_1
2612 = k + a * k + a^2 * rate_0
2613 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2614 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2615 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2616 = rate_0 * a^N + p/i * (1 - a^N)
2618 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2620 rate_N = p/i + (rate_0 - p/i) * a^N
2621 a^N = (rate_N - p/i) / (rate_0 - p/i)
2622 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2623 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2625 Numerical analysis of the above equation, setting the computed rate to
2626 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2627 rates, p/i, the number of messages N = limit. So limit serves as both the
2628 maximum rate measured in messages per period, and the maximum number of
2629 messages that can be sent in a fast burst. */
2631 double this_time = (double)tv.tv_sec
2632 + (double)tv.tv_usec / 1000000.0;
2633 double prev_time = (double)dbd->time_stamp
2634 + (double)dbd->time_usec / 1000000.0;
2636 /* We must avoid division by zero, and deal gracefully with the clock going
2637 backwards. If we blunder ahead when time is in reverse then the computed
2638 rate will be bogus. To be safe we clamp interval to a very small number. */
2640 double interval = this_time - prev_time <= 0.0 ? 1e-9
2641 : this_time - prev_time;
2643 double i_over_p = interval / period;
2644 double a = exp(-i_over_p);
2646 /* Combine the instantaneous rate (period / interval) with the previous rate
2647 using the smoothing factor a. In order to measure sized events, multiply the
2648 instantaneous rate by the count of bytes or recipients etc. */
2650 dbd->time_stamp = tv.tv_sec;
2651 dbd->time_usec = tv.tv_usec;
2652 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2654 /* When events are very widely spaced the computed rate tends towards zero.
2655 Although this is accurate it turns out not to be useful for our purposes,
2656 especially when the first event after a long silence is the start of a spam
2657 run. A more useful model is that the rate for an isolated event should be the
2658 size of the event per the period size, ignoring the lack of events outside
2659 the current period and regardless of where the event falls in the period. So,
2660 if the interval was so long that the calculated rate is unhelpfully small, we
2661 re-initialize the rate. In the absence of higher-rate bursts, the condition
2662 below is true if the interval is greater than the period. */
2664 if (dbd->rate < count) dbd->rate = count;
2667 /* Clients sending at the limit are considered to be over the limit.
2668 This matters for edge cases such as a limit of zero, when the client
2669 should be completely blocked. */
2671 rc = dbd->rate < limit ? FAIL : OK;
2673 /* Update the state if the rate is low or if we are being strict. If we
2674 are in leaky mode and the sender's rate is too high, we do not update
2675 the recorded rate in order to avoid an over-aggressive sender's retry
2676 rate preventing them from getting any email through. If readonly is set,
2677 neither leaky nor strict are set, so we do not do any updates. */
2679 if ((rc == FAIL && leaky) || strict)
2681 dbfn_write(dbm, key, dbdb, dbdb_size);
2682 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2686 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2687 readonly? "readonly mode" : "over the limit, but leaky");
2692 /* Store the result in the tree for future reference. Take the taint status
2693 from the key for consistency even though it's unlikely we'll ever expand this. */
2695 t = store_get(sizeof(tree_node) + Ustrlen(key), is_tainted(key));
2697 Ustrcpy(t->name, key);
2698 (void)tree_insertnode(anchor, t);
2700 /* We create the formatted version of the sender's rate very late in
2701 order to ensure that it is done using the correct storage pool. */
2703 store_pool = old_pool;
2704 sender_rate = string_sprintf("%.1f", dbd->rate);
2707 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2714 /*************************************************
2715 * The udpsend ACL modifier *
2716 *************************************************/
2718 /* Called by acl_check_condition() below.
2721 arg the option string for udpsend=
2722 log_msgptr for error messages
2724 Returns: OK - Completed.
2725 DEFER - Problem with DNS lookup.
2726 ERROR - Syntax error in options.
2730 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2742 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2743 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2747 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2752 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2757 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2760 portnum = Ustrtol(portstr, &portend, 10);
2761 if (*portend != '\0')
2763 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2767 /* Make a single-item host list. */
2768 h = store_get(sizeof(host_item), FALSE);
2769 memset(h, 0, sizeof(host_item));
2774 if (string_is_ip_address(hostname, NULL))
2775 h->address = hostname, r = HOST_FOUND;
2777 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2778 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2780 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2785 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2787 /*XXX this could better use sendto */
2788 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2789 1, NULL, &errstr, NULL);
2790 if (r < 0) goto defer;
2792 r = send(s, arg, len, 0);
2795 errstr = US strerror(errno);
2803 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2808 debug_printf_indent("udpsend %d bytes\n", r);
2813 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2819 /*************************************************
2820 * Handle conditions/modifiers on an ACL item *
2821 *************************************************/
2823 /* Called from acl_check() below.
2827 cb ACL condition block - if NULL, result is OK
2828 where where called from
2829 addr the address being checked for RCPT, or NULL
2830 level the nesting level
2831 epp pointer to pass back TRUE if "endpass" encountered
2832 (applies only to "accept" and "discard")
2833 user_msgptr user message pointer
2834 log_msgptr log message pointer
2835 basic_errno pointer to where to put verify error
2837 Returns: OK - all conditions are met
2838 DISCARD - an "acl" condition returned DISCARD - only allowed
2839 for "accept" or "discard" verbs
2840 FAIL - at least one condition fails
2841 FAIL_DROP - an "acl" condition returned FAIL_DROP
2842 DEFER - can't tell at the moment (typically, lookup defer,
2843 but can be temporary callout problem)
2844 ERROR - ERROR from nested ACL or expansion failure or other
2849 acl_check_condition(int verb, acl_condition_block *cb, int where,
2850 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2851 uschar **log_msgptr, int *basic_errno)
2853 uschar *user_message = NULL;
2854 uschar *log_message = NULL;
2856 #ifdef WITH_CONTENT_SCAN
2860 for (; cb; cb = cb->next)
2865 /* The message and log_message items set up messages to be used in
2866 case of rejection. They are expanded later. */
2868 if (cb->type == ACLC_MESSAGE)
2870 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2871 user_message = cb->arg;
2875 if (cb->type == ACLC_LOG_MESSAGE)
2877 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2878 log_message = cb->arg;
2882 /* The endpass "condition" just sets a flag to show it occurred. This is
2883 checked at compile time to be on an "accept" or "discard" item. */
2885 if (cb->type == ACLC_ENDPASS)
2891 /* For other conditions and modifiers, the argument is expanded now for some
2892 of them, but not for all, because expansion happens down in some lower level
2893 checking functions in some cases. */
2895 if (!conditions[cb->type].expand_at_top)
2897 else if (!(arg = expand_string(cb->arg)))
2899 if (f.expand_string_forcedfail) continue;
2900 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2901 cb->arg, expand_string_message);
2902 return f.search_find_defer ? DEFER : ERROR;
2905 /* Show condition, and expanded condition if it's different */
2910 debug_printf_indent("check %s%s %n",
2911 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2912 conditions[cb->type].name, &lhswidth);
2914 if (cb->type == ACLC_SET)
2916 #ifndef DISABLE_DKIM
2917 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2918 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2920 debug_printf("%s ", cb->u.varname);
2926 debug_printf("acl_%s ", cb->u.varname);
2927 lhswidth += 5 + Ustrlen(cb->u.varname);
2931 debug_printf("= %s\n", cb->arg);
2934 debug_printf("%.*s= %s\n", lhswidth,
2938 /* Check that this condition makes sense at this time */
2940 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2942 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2943 conditions[cb->type].is_modifier ? "use" : "test",
2944 conditions[cb->type].name, acl_wherenames[where]);
2948 /* Run the appropriate test for each condition, or take the appropriate
2949 action for the remaining modifiers. */
2953 case ACLC_ADD_HEADER:
2957 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2961 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2962 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2964 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2965 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2971 case ACLC_AUTHENTICATED:
2972 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
2973 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
2976 #ifdef EXPERIMENTAL_BRIGHTMAIL
2977 case ACLC_BMI_OPTIN:
2979 int old_pool = store_pool;
2980 store_pool = POOL_PERM;
2981 bmi_current_optin = string_copy(arg);
2982 store_pool = old_pool;
2987 case ACLC_CONDITION:
2988 /* The true/false parsing here should be kept in sync with that used in
2989 expand.c when dealing with ECOND_BOOL so that we don't have too many
2990 different definitions of what can be a boolean. */
2992 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
2993 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2994 rc = (Uatoi(arg) == 0)? FAIL : OK;
2996 rc = (strcmpic(arg, US"no") == 0 ||
2997 strcmpic(arg, US"false") == 0)? FAIL :
2998 (strcmpic(arg, US"yes") == 0 ||
2999 strcmpic(arg, US"true") == 0)? OK : DEFER;
3001 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3004 case ACLC_CONTINUE: /* Always succeeds */
3009 const uschar *p = NULL;
3010 control_type = decode_control(arg, &p, where, log_msgptr);
3012 /* Check if this control makes sense at this time */
3014 if (controls_list[control_type].forbids & (1 << where))
3016 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3017 controls_list[control_type].name, acl_wherenames[where]);
3021 switch(control_type)
3023 case CONTROL_AUTH_UNADVERTISED:
3024 f.allow_auth_unadvertised = TRUE;
3027 #ifdef EXPERIMENTAL_BRIGHTMAIL
3028 case CONTROL_BMI_RUN:
3033 #ifndef DISABLE_DKIM
3034 case CONTROL_DKIM_VERIFY:
3035 f.dkim_disable_verify = TRUE;
3036 # ifdef SUPPORT_DMARC
3037 /* Since DKIM was blocked, skip DMARC too */
3038 f.dmarc_disable_verify = TRUE;
3039 f.dmarc_enable_forensic = FALSE;
3044 #ifdef SUPPORT_DMARC
3045 case CONTROL_DMARC_VERIFY:
3046 f.dmarc_disable_verify = TRUE;
3049 case CONTROL_DMARC_FORENSIC:
3050 f.dmarc_enable_forensic = TRUE;
3057 int fd, af, level, optname, value;
3058 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3059 a socket; we can accept that, we'll just debug-log failures anyway. */
3060 fd = fileno(smtp_in);
3061 if ((af = ip_get_address_family(fd)) < 0)
3064 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3068 if (dscp_lookup(p+1, af, &level, &optname, &value))
3069 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3071 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3072 p+1, strerror(errno));
3076 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3080 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3086 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3094 case CONTROL_CASEFUL_LOCAL_PART:
3095 deliver_localpart = addr->cc_local_part;
3098 case CONTROL_CASELOWER_LOCAL_PART:
3099 deliver_localpart = addr->lc_local_part;
3102 case CONTROL_ENFORCE_SYNC:
3103 smtp_enforce_sync = TRUE;
3106 case CONTROL_NO_ENFORCE_SYNC:
3107 smtp_enforce_sync = FALSE;
3110 #ifdef WITH_CONTENT_SCAN
3111 case CONTROL_NO_MBOX_UNSPOOL:
3112 f.no_mbox_unspool = TRUE;
3116 case CONTROL_NO_MULTILINE:
3117 f.no_multiline_responses = TRUE;
3120 case CONTROL_NO_PIPELINING:
3121 f.pipelining_enable = FALSE;
3124 case CONTROL_NO_DELAY_FLUSH:
3125 f.disable_delay_flush = TRUE;
3128 case CONTROL_NO_CALLOUT_FLUSH:
3129 f.disable_callout_flush = TRUE;
3132 case CONTROL_FAKEREJECT:
3133 cancel_cutthrough_connection(TRUE, US"fakereject");
3134 case CONTROL_FAKEDEFER:
3135 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3138 const uschar *pp = p + 1;
3140 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3143 else /* Explicitly reset to default string */
3144 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).";
3147 case CONTROL_FREEZE:
3148 f.deliver_freeze = TRUE;
3149 deliver_frozen_at = time(NULL);
3150 freeze_tell = freeze_tell_config; /* Reset to configured value */
3151 if (Ustrncmp(p, "/no_tell", 8) == 0)
3158 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3161 cancel_cutthrough_connection(TRUE, US"item frozen");
3165 f.queue_only_policy = TRUE;
3166 if (Ustrcmp(p, "_only") == 0)
3168 else while (*p == '/')
3169 if (Ustrncmp(p, "/only", 5) == 0)
3170 { p += 5; f.queue_smtp = FALSE; }
3171 else if (Ustrncmp(p, "/first_pass_route", 17) == 0)
3172 { p += 17; f.queue_smtp = TRUE; }
3175 cancel_cutthrough_connection(TRUE, US"queueing forced");
3178 case CONTROL_SUBMISSION:
3179 originator_name = US"";
3180 f.submission_mode = TRUE;
3183 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3186 f.active_local_sender_retain = TRUE;
3187 f.active_local_from_check = FALSE;
3189 else if (Ustrncmp(p, "/domain=", 8) == 0)
3191 const uschar *pp = p + 8;
3192 while (*pp && *pp != '/') pp++;
3193 submission_domain = string_copyn(p+8, pp-p-8);
3196 /* The name= option must be last, because it swallows the rest of
3198 else if (Ustrncmp(p, "/name=", 6) == 0)
3200 const uschar *pp = p + 6;
3202 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3203 big_buffer, big_buffer_size));
3210 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3217 uschar * debug_tag = NULL;
3218 uschar * debug_opts = NULL;
3223 const uschar * pp = p+1;
3224 if (Ustrncmp(pp, "tag=", 4) == 0)
3226 for (pp += 4; *pp && *pp != '/';) pp++;
3227 debug_tag = string_copyn(p+5, pp-p-5);
3229 else if (Ustrncmp(pp, "opts=", 5) == 0)
3231 for (pp += 5; *pp && *pp != '/';) pp++;
3232 debug_opts = string_copyn(p+6, pp-p-6);
3234 else if (Ustrncmp(pp, "kill", 4) == 0)
3236 for (pp += 4; *pp && *pp != '/';) pp++;
3240 while (*pp && *pp != '/') pp++;
3245 debug_logging_stop();
3247 debug_logging_activate(debug_tag, debug_opts);
3251 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3252 f.suppress_local_fixups = TRUE;
3255 case CONTROL_CUTTHROUGH_DELIVERY:
3257 uschar * ignored = NULL;
3258 #ifndef DISABLE_PRDR
3263 /* Too hard to think about for now. We might in future cutthrough
3264 the case where both sides handle prdr and this-node prdr acl
3266 ignored = US"PRDR active";
3269 if (f.deliver_freeze)
3270 ignored = US"frozen";
3271 else if (f.queue_only_policy)
3272 ignored = US"queue-only";
3273 else if (fake_response == FAIL)
3274 ignored = US"fakereject";
3277 if (rcpt_count == 1)
3279 cutthrough.delivery = TRUE; /* control accepted */
3282 const uschar * pp = p+1;
3283 if (Ustrncmp(pp, "defer=", 6) == 0)
3286 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3287 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3290 while (*pp && *pp != '/') pp++;
3295 ignored = US"nonfirst rcpt";
3298 DEBUG(D_acl) if (ignored)
3299 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3304 case CONTROL_UTF8_DOWNCONVERT:
3309 message_utf8_downconvert = 1;
3310 addr->prop.utf8_downcvt = TRUE;
3311 addr->prop.utf8_downcvt_maybe = FALSE;
3317 message_utf8_downconvert = 0;
3318 addr->prop.utf8_downcvt = FALSE;
3319 addr->prop.utf8_downcvt_maybe = FALSE;
3323 if (p[1] == '-' && p[2] == '1')
3325 message_utf8_downconvert = -1;
3326 addr->prop.utf8_downcvt = FALSE;
3327 addr->prop.utf8_downcvt_maybe = TRUE;
3331 *log_msgptr = US"bad option value for control=utf8_downconvert";
3335 message_utf8_downconvert = 1;
3336 addr->prop.utf8_downcvt = TRUE;
3337 addr->prop.utf8_downcvt_maybe = FALSE;
3347 #ifdef EXPERIMENTAL_DCC
3350 /* Separate the regular expression and any optional parameters. */
3351 const uschar * list = arg;
3352 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3353 /* Run the dcc backend. */
3354 rc = dcc_process(&ss);
3355 /* Modify return code based upon the existence of options. */
3356 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3357 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3358 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3363 #ifdef WITH_CONTENT_SCAN
3365 rc = mime_decode(&arg);
3371 int delay = readconf_readtime(arg, 0, FALSE);
3374 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3375 "modifier: \"%s\" is not a time value", arg);
3380 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3385 debug_printf_indent("delay skipped in -bh checking mode\n");
3388 /* NOTE 1: Remember that we may be
3389 dealing with stdin/stdout here, in addition to TCP/IP connections.
3390 Also, delays may be specified for non-SMTP input, where smtp_out and
3391 smtp_in will be NULL. Whatever is done must work in all cases.
3393 NOTE 2: The added feature of flushing the output before a delay must
3394 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3399 if (smtp_out && !f.disable_delay_flush)
3402 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3408 p.fd = fileno(smtp_out);
3409 p.events = POLLRDHUP;
3412 if (poll(&p, n, delay*1000) > 0)
3413 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3416 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3417 TCP/IP connection has gone away without reading from it. This means
3418 that we cannot shorten the delay below if the client goes away,
3419 because we cannot discover that the client has closed its end of the
3420 connection. (The connection is actually in a half-closed state,
3421 waiting for the server to close its end.) It would be nice to be able
3422 to detect this state, so that the Exim process is not held up
3423 unnecessarily. However, it seems that we can't. The poll() function
3424 does not do the right thing, and in any case it is not always
3427 while (delay > 0) delay = sleep(delay);
3434 #ifndef DISABLE_DKIM
3435 case ACLC_DKIM_SIGNER:
3436 if (dkim_cur_signer)
3437 rc = match_isinlist(dkim_cur_signer,
3438 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3443 case ACLC_DKIM_STATUS:
3444 rc = match_isinlist(dkim_verify_status,
3445 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3449 #ifdef SUPPORT_DMARC
3450 case ACLC_DMARC_STATUS:
3451 if (!f.dmarc_has_been_checked)
3453 f.dmarc_has_been_checked = TRUE;
3454 /* used long way of dmarc_exim_expand_query() in case we need more
3455 * view into the process in the future. */
3456 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3457 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3462 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3466 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3467 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3470 /* The value in tls_cipher is the full cipher name, for example,
3471 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3472 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3473 what may in practice come out of the SSL library - which at the time of
3474 writing is poorly documented. */
3476 case ACLC_ENCRYPTED:
3477 if (tls_in.cipher == NULL) rc = FAIL; else
3479 uschar *endcipher = NULL;
3480 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3481 if (cipher == NULL) cipher = tls_in.cipher; else
3483 endcipher = Ustrchr(++cipher, ':');
3484 if (endcipher != NULL) *endcipher = 0;
3486 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3487 if (endcipher != NULL) *endcipher = ':';
3491 /* Use verify_check_this_host() instead of verify_check_host() so that
3492 we can pass over &host_data to catch any looked up data. Once it has been
3493 set, it retains its value so that it's still there if another ACL verb
3494 comes through here and uses the cache. However, we must put it into
3495 permanent store in case it is also expected to be used in a subsequent
3496 message in the same SMTP connection. */
3499 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3500 (sender_host_address == NULL)? US"" : sender_host_address,
3502 if (rc == DEFER) *log_msgptr = search_error_message;
3503 if (host_data) host_data = string_copy_perm(host_data, TRUE);
3506 case ACLC_LOCAL_PARTS:
3507 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3508 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3509 CUSS &deliver_localpart_data);
3512 case ACLC_LOG_REJECT_TARGET:
3516 const uschar *s = arg;
3518 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3520 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3521 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3522 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3525 logbits |= LOG_MAIN|LOG_REJECT;
3526 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3527 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3530 log_reject_target = logbits;
3537 const uschar *s = arg;
3543 if (Ustrncmp(s, "main", 4) == 0)
3544 { logbits |= LOG_MAIN; s += 4; }
3545 else if (Ustrncmp(s, "panic", 5) == 0)
3546 { logbits |= LOG_PANIC; s += 5; }
3547 else if (Ustrncmp(s, "reject", 6) == 0)
3548 { logbits |= LOG_REJECT; s += 6; }
3551 logbits = LOG_MAIN|LOG_PANIC;
3552 s = string_sprintf(":unknown log name in \"%s\" in "
3553 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3559 while (isspace(*s)) s++;
3561 if (logbits == 0) logbits = LOG_MAIN;
3562 log_write(0, logbits, "%s", string_printing(s));
3566 #ifdef WITH_CONTENT_SCAN
3567 case ACLC_MALWARE: /* Run the malware backend. */
3569 /* Separate the regular expression and any optional parameters. */
3570 const uschar * list = arg;
3571 uschar * ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3573 BOOL defer_ok = FALSE;
3576 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3577 if (strcmpic(opt, US"defer_ok") == 0)
3579 else if ( strncmpic(opt, US"tmo=", 4) == 0
3580 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3583 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3587 rc = malware(ss, timeout);
3588 if (rc == DEFER && defer_ok)
3589 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3593 case ACLC_MIME_REGEX:
3594 rc = mime_regex(&arg);
3599 if (is_tainted(arg))
3601 *log_msgptr = string_sprintf("Tainted name '%s' for queue not permitted",
3605 if (Ustrchr(arg, '/'))
3607 *log_msgptr = string_sprintf(
3608 "Directory separator not permitted in queue name: '%s'", arg);
3611 queue_name = string_copy_perm(arg, FALSE);
3614 case ACLC_RATELIMIT:
3615 rc = acl_ratelimit(arg, where, log_msgptr);
3618 case ACLC_RECIPIENTS:
3619 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3620 CUSS &recipient_data);
3623 #ifdef WITH_CONTENT_SCAN
3629 case ACLC_REMOVE_HEADER:
3630 setup_remove_header(arg);
3633 case ACLC_SENDER_DOMAINS:
3636 sdomain = Ustrrchr(sender_address, '@');
3637 sdomain = sdomain ? sdomain + 1 : US"";
3638 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3639 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3644 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3645 sender_address_cache, -1, 0, CUSS &sender_data);
3648 /* Connection variables must persist forever; message variables not */
3652 int old_pool = store_pool;
3653 if ( cb->u.varname[0] != 'm'
3654 #ifndef DISABLE_EVENT
3655 || event_name /* An event is being delivered */
3658 store_pool = POOL_PERM;
3659 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3660 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3661 dkim_verify_status = string_copy(arg);
3662 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3663 dkim_verify_reason = string_copy(arg);
3666 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3667 store_pool = old_pool;
3671 #ifdef WITH_CONTENT_SCAN
3674 /* Separate the regular expression and any optional parameters. */
3675 const uschar * list = arg;
3676 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3678 rc = spam(CUSS &ss);
3679 /* Modify return code based upon the existence of options. */
3680 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3681 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3682 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3689 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3691 case ACLC_SPF_GUESS:
3692 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3697 rc = acl_udpsend(arg, log_msgptr);
3700 /* If the verb is WARN, discard any user message from verification, because
3701 such messages are SMTP responses, not header additions. The latter come
3702 only from explicit "message" modifiers. However, put the user message into
3703 $acl_verify_message so it can be used in subsequent conditions or modifiers
3704 (until something changes it). */
3707 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3709 acl_verify_message = *user_msgptr;
3710 if (verb == ACL_WARN) *user_msgptr = NULL;
3714 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3715 "condition %d", cb->type);
3719 /* If a condition was negated, invert OK/FAIL. */
3721 if (!conditions[cb->type].is_modifier && cb->u.negated)
3722 if (rc == OK) rc = FAIL;
3723 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3725 if (rc != OK) break; /* Conditions loop */
3729 /* If the result is the one for which "message" and/or "log_message" are used,
3730 handle the values of these modifiers. If there isn't a log message set, we make
3731 it the same as the user message.
3733 "message" is a user message that will be included in an SMTP response. Unless
3734 it is empty, it overrides any previously set user message.
3736 "log_message" is a non-user message, and it adds to any existing non-user
3737 message that is already set.
3739 Most verbs have but a single return for which the messages are relevant, but
3740 for "discard", it's useful to have the log message both when it succeeds and
3741 when it fails. For "accept", the message is used in the OK case if there is no
3742 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3745 if (*epp && rc == OK) user_message = NULL;
3747 if ((BIT(rc) & msgcond[verb]) != 0)
3750 uschar *old_user_msgptr = *user_msgptr;
3751 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3753 /* If the verb is "warn", messages generated by conditions (verification or
3754 nested ACLs) are always discarded. This also happens for acceptance verbs
3755 when they actually do accept. Only messages specified at this level are used.
3756 However, the value of an existing message is available in $acl_verify_message
3757 during expansions. */
3759 if (verb == ACL_WARN ||
3760 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3761 *log_msgptr = *user_msgptr = NULL;
3765 acl_verify_message = old_user_msgptr;
3766 expmessage = expand_string(user_message);
3769 if (!f.expand_string_forcedfail)
3770 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3771 user_message, expand_string_message);
3773 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3778 acl_verify_message = old_log_msgptr;
3779 expmessage = expand_string(log_message);
3782 if (!f.expand_string_forcedfail)
3783 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3784 log_message, expand_string_message);
3786 else if (expmessage[0] != 0)
3788 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3789 string_sprintf("%s: %s", expmessage, *log_msgptr);
3793 /* If no log message, default it to the user message */
3795 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3798 acl_verify_message = NULL;
3806 /*************************************************
3807 * Get line from a literal ACL *
3808 *************************************************/
3810 /* This function is passed to acl_read() in order to extract individual lines
3811 of a literal ACL, which we access via static pointers. We can destroy the
3812 contents because this is called only once (the compiled ACL is remembered).
3814 This code is intended to treat the data in the same way as lines in the main
3815 Exim configuration file. That is:
3817 . Leading spaces are ignored.
3819 . A \ at the end of a line is a continuation - trailing spaces after the \
3820 are permitted (this is because I don't believe in making invisible things
3821 significant). Leading spaces on the continued part of a line are ignored.
3823 . Physical lines starting (significantly) with # are totally ignored, and
3824 may appear within a sequence of backslash-continued lines.
3826 . Blank lines are ignored, but will end a sequence of continuations.
3829 Returns: a pointer to the next line
3833 static uschar *acl_text; /* Current pointer in the text */
3834 static uschar *acl_text_end; /* Points one past the terminating '0' */
3842 /* This loop handles leading blank lines and comments. */
3846 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3847 if (*acl_text == 0) return NULL; /* No more data */
3848 yield = acl_text; /* Potential data line */
3850 while (*acl_text && *acl_text != '\n') acl_text++;
3852 /* If we hit the end before a newline, we have the whole logical line. If
3853 it's a comment, there's no more data to be given. Otherwise, yield it. */
3855 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3857 /* After reaching a newline, end this loop if the physical line does not
3858 start with '#'. If it does, it's a comment, and the loop continues. */
3860 if (*yield != '#') break;
3863 /* This loop handles continuations. We know we have some real data, ending in
3864 newline. See if there is a continuation marker at the end (ignoring trailing
3865 white space). We know that *yield is not white space, so no need to test for
3866 cont > yield in the backwards scanning loop. */
3871 for (cont = acl_text - 1; isspace(*cont); cont--);
3873 /* If no continuation follows, we are done. Mark the end of the line and
3882 /* We have encountered a continuation. Skip over whitespace at the start of
3883 the next line, and indeed the whole of the next line or lines if they are
3888 while (*(++acl_text) == ' ' || *acl_text == '\t');
3889 if (*acl_text != '#') break;
3890 while (*(++acl_text) != 0 && *acl_text != '\n');
3893 /* We have the start of a continuation line. Move all the rest of the data
3894 to join onto the previous line, and then find its end. If the end is not a
3895 newline, we are done. Otherwise loop to look for another continuation. */
3897 memmove(cont, acl_text, acl_text_end - acl_text);
3898 acl_text_end -= acl_text - cont;
3900 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3901 if (*acl_text == 0) return yield;
3904 /* Control does not reach here */
3911 /*************************************************
3912 * Check access using an ACL *
3913 *************************************************/
3915 /* This function is called from address_check. It may recurse via
3916 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3917 passed as a string which is expanded. A forced failure implies no access check
3918 is required. If the result is a single word, it is taken as the name of an ACL
3919 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3920 text, complete with newlines, and parsed as such. In both cases, the ACL check
3921 is then run. This function uses an auxiliary function for acl_read() to call
3922 for reading individual lines of a literal ACL. This is acl_getline(), which
3923 appears immediately above.
3926 where where called from
3927 addr address item when called from RCPT; otherwise NULL
3928 s the input string; NULL is the same as an empty ACL => DENY
3929 user_msgptr where to put a user error (for SMTP response)
3930 log_msgptr where to put a logging message (not for SMTP response)
3932 Returns: OK access is granted
3933 DISCARD access is apparently granted...
3934 FAIL access is denied
3935 FAIL_DROP access is denied; drop the connection
3936 DEFER can't tell at the moment
3941 acl_check_internal(int where, address_item *addr, uschar *s,
3942 uschar **user_msgptr, uschar **log_msgptr)
3945 acl_block *acl = NULL;
3946 uschar *acl_name = US"inline ACL";
3949 /* Catch configuration loops */
3953 *log_msgptr = US"ACL nested too deep: possible loop";
3959 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3963 /* At top level, we expand the incoming string. At lower levels, it has already
3964 been expanded as part of condition processing. */
3968 if (!(ss = expand_string(s)))
3970 if (f.expand_string_forcedfail) return OK;
3971 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3972 expand_string_message);
3978 while (isspace(*ss)) ss++;
3980 /* If we can't find a named ACL, the default is to parse it as an inline one.
3981 (Unless it begins with a slash; non-existent files give rise to an error.) */
3985 /* Handle the case of a string that does not contain any spaces. Look for a
3986 named ACL among those read from the configuration, or a previously read file.
3987 It is possible that the pointer to the ACL is NULL if the configuration
3988 contains a name with no data. If not found, and the text begins with '/',
3989 read an ACL from a file, and save it so it can be re-used. */
3991 if (Ustrchr(ss, ' ') == NULL)
3993 tree_node * t = tree_search(acl_anchor, ss);
3996 if (!(acl = (acl_block *)(t->data.ptr)))
3998 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
4001 acl_name = string_sprintf("ACL \"%s\"", ss);
4002 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4005 else if (*ss == '/')
4007 struct stat statbuf;
4010 log_write(0, LOG_MAIN|LOG_PANIC,
4011 "attempt to open tainted ACL file name \"%s\"", ss);
4012 /* Avoid leaking info to an attacker */
4013 *log_msgptr = US"internal configuration error";
4016 if ((fd = Uopen(ss, O_RDONLY, 0)) < 0)
4018 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4022 if (fstat(fd, &statbuf) != 0)
4024 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4029 /* If the string being used as a filename is tainted, so is the file content */
4030 acl_text = store_get(statbuf.st_size + 1, is_tainted(ss));
4031 acl_text_end = acl_text + statbuf.st_size + 1;
4033 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4035 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4036 ss, strerror(errno));
4039 acl_text[statbuf.st_size] = 0;
4042 acl_name = string_sprintf("ACL \"%s\"", ss);
4043 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4047 /* Parse an ACL that is still in text form. If it came from a file, remember it
4048 in the ACL tree, having read it into the POOL_PERM store pool so that it
4049 persists between multiple messages. */
4053 int old_pool = store_pool;
4054 if (fd >= 0) store_pool = POOL_PERM;
4055 acl = acl_read(acl_getline, log_msgptr);
4056 store_pool = old_pool;
4057 if (!acl && *log_msgptr) return ERROR;
4060 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss), is_tainted(ss));
4061 Ustrcpy(t->name, ss);
4063 (void)tree_insertnode(&acl_anchor, t);
4067 /* Now we have an ACL to use. It's possible it may be NULL. */
4072 int basic_errno = 0;
4073 BOOL endpass_seen = FALSE;
4074 BOOL acl_quit_check = acl_level == 0
4075 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4077 *log_msgptr = *user_msgptr = NULL;
4078 f.acl_temp_details = FALSE;
4080 HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n",
4081 verbs[acl->verb], acl->srcfile, acl->srcline);
4083 /* Clear out any search error message from a previous check before testing
4086 search_error_message = NULL;
4087 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4088 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4090 /* Handle special returns: DEFER causes a return except on a WARN verb;
4091 ERROR always causes a return. */
4096 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n",
4097 verbs[acl->verb], acl_name);
4098 if (basic_errno != ERRNO_CALLOUTDEFER)
4100 if (search_error_message != NULL && *search_error_message != 0)
4101 *log_msgptr = search_error_message;
4102 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4105 f.acl_temp_details = TRUE;
4106 if (acl->verb != ACL_WARN) return DEFER;
4109 default: /* Paranoia */
4111 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n",
4112 verbs[acl->verb], acl_name);
4116 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4117 verbs[acl->verb], acl_name);
4121 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n",
4122 verbs[acl->verb], acl_name);
4125 /* DISCARD and DROP can happen only from a nested ACL condition, and
4126 DISCARD can happen only for an "accept" or "discard" verb. */
4129 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4130 verbs[acl->verb], acl_name);
4134 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4135 verbs[acl->verb], acl_name);
4139 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4140 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4141 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4146 if (cond == OK || cond == DISCARD)
4148 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4153 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4161 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4162 if (acl_quit_check) goto badquit;
4163 f.acl_temp_details = TRUE;
4171 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4172 if (acl_quit_check) goto badquit;
4178 if (cond == OK || cond == DISCARD)
4180 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4181 if (acl_quit_check) goto badquit;
4187 debug_printf_indent("discard: endpass encountered - denying access\n");
4195 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4196 if (acl_quit_check) goto badquit;
4204 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4205 if (acl_quit_check) goto badquit;
4212 acl_warn(where, *user_msgptr, *log_msgptr);
4213 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4214 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4215 "condition test deferred%s%s", host_and_ident(TRUE),
4216 (*log_msgptr == NULL)? US"" : US": ",
4217 (*log_msgptr == NULL)? US"" : *log_msgptr);
4218 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4222 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4227 /* Pass to the next ACL item */
4232 /* We have reached the end of the ACL. This is an implicit DENY. */
4234 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4238 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4239 "('%s' verb used incorrectly)", verbs[acl->verb]);
4246 /* Same args as acl_check_internal() above, but the string s is
4247 the name of an ACL followed optionally by up to 9 space-separated arguments.
4248 The name and args are separately expanded. Args go into $acl_arg globals. */
4250 acl_check_wargs(int where, address_item *addr, const uschar *s,
4251 uschar **user_msgptr, uschar **log_msgptr)
4254 uschar * tmp_arg[9]; /* must match acl_arg[] */
4255 uschar * sav_arg[9]; /* must match acl_arg[] */
4261 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4264 for (i = 0; i < 9; i++)
4266 while (*s && isspace(*s)) s++;
4268 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4275 sav_narg = acl_narg;
4277 for (i = 0; i < acl_narg; i++)
4279 sav_arg[i] = acl_arg[i];
4280 acl_arg[i] = tmp_arg[i];
4284 sav_arg[i] = acl_arg[i];
4285 acl_arg[i++] = NULL;
4289 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4292 acl_narg = sav_narg;
4293 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4297 if (f.expand_string_forcedfail) return ERROR;
4298 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4299 tmp, expand_string_message);
4300 return f.search_find_defer ? DEFER : ERROR;
4305 /*************************************************
4306 * Check access using an ACL *
4307 *************************************************/
4309 /* Alternate interface for ACL, used by expansions */
4311 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4314 address_item *addr = NULL;
4317 *user_msgptr = *log_msgptr = NULL;
4318 sender_verified_failed = NULL;
4319 ratelimiters_cmd = NULL;
4320 log_reject_target = LOG_MAIN|LOG_REJECT;
4322 if (where == ACL_WHERE_RCPT)
4324 adb = address_defaults;
4326 addr->address = expand_string(US"$local_part@$domain");
4327 addr->domain = deliver_domain;
4328 addr->local_part = deliver_localpart;
4329 addr->cc_local_part = deliver_localpart;
4330 addr->lc_local_part = deliver_localpart;
4334 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4341 /* This is the external interface for ACL checks. It sets up an address and the
4342 expansions for $domain and $local_part when called after RCPT, then calls
4343 acl_check_internal() to do the actual work.
4346 where ACL_WHERE_xxxx indicating where called from
4347 recipient RCPT address for RCPT check, else NULL
4348 s the input string; NULL is the same as an empty ACL => DENY
4349 user_msgptr where to put a user error (for SMTP response)
4350 log_msgptr where to put a logging message (not for SMTP response)
4352 Returns: OK access is granted by an ACCEPT verb
4353 DISCARD access is granted by a DISCARD verb
4354 FAIL access is denied
4355 FAIL_DROP access is denied; drop the connection
4356 DEFER can't tell at the moment
4359 int acl_where = ACL_WHERE_UNKNOWN;
4362 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4363 uschar **log_msgptr)
4367 address_item *addr = NULL;
4369 *user_msgptr = *log_msgptr = NULL;
4370 sender_verified_failed = NULL;
4371 ratelimiters_cmd = NULL;
4372 log_reject_target = LOG_MAIN|LOG_REJECT;
4374 #ifndef DISABLE_PRDR
4375 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4377 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4380 adb = address_defaults;
4382 addr->address = recipient;
4383 if (deliver_split_address(addr) == DEFER)
4385 *log_msgptr = US"defer in percent_hack_domains check";
4389 if ((addr->prop.utf8_msg = message_smtputf8))
4391 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4392 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4395 deliver_domain = addr->domain;
4396 deliver_localpart = addr->local_part;
4401 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4403 acl_where = ACL_WHERE_UNKNOWN;
4405 /* Cutthrough - if requested,
4406 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4407 and rcpt acl returned accept,
4408 and first recipient (cancel on any subsequents)
4409 open one now and run it up to RCPT acceptance.
4410 A failed verify should cancel cutthrough request,
4411 and will pass the fail to the originator.
4412 Initial implementation: dual-write to spool.
4413 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4415 Cease cutthrough copy on rxd final dot; do not send one.
4417 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4419 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4420 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4421 If temp-reject, close the conn (and keep the spooled copy).
4422 If conn-failure, no action (and keep the spooled copy).
4426 case ACL_WHERE_RCPT:
4427 #ifndef DISABLE_PRDR
4428 case ACL_WHERE_PRDR:
4431 if (f.host_checking_callout) /* -bhc mode */
4432 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4435 && cutthrough.delivery
4436 && rcpt_count > cutthrough.nrcpt
4439 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4440 if (cutthrough.defer_pass)
4442 uschar * s = addr->message;
4443 /* Horrid kludge to recover target's SMTP message */
4445 do --s; while (!isdigit(*s));
4446 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4447 f.acl_temp_details = TRUE;
4451 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4455 else HDEBUG(D_acl) if (cutthrough.delivery)
4456 if (rcpt_count <= cutthrough.nrcpt)
4457 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4459 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4462 case ACL_WHERE_PREDATA:
4464 cutthrough_predata();
4466 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4469 case ACL_WHERE_QUIT:
4470 case ACL_WHERE_NOTQUIT:
4471 /* Drop cutthrough conns, and drop heldopen verify conns if
4472 the previous was not DATA */
4474 uschar prev = smtp_connection_had[smtp_ch_index-2];
4475 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4477 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4485 deliver_domain = deliver_localpart = deliver_address_data =
4486 deliver_domain_data = sender_address_data = NULL;
4488 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4489 ACL, which is really in the middle of an SMTP command. */
4493 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4495 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4496 "ACL", acl_wherenames[where]);
4502 /* A DROP response is not permitted from MAILAUTH */
4504 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4506 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4507 "ACL", acl_wherenames[where]);
4511 /* Before giving a response, take a look at the length of any user message, and
4512 split it up into multiple lines if possible. */
4514 *user_msgptr = string_split_message(*user_msgptr);
4515 if (fake_response != OK)
4516 fake_response_text = string_split_message(fake_response_text);
4522 /*************************************************
4523 * Create ACL variable *
4524 *************************************************/
4526 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4527 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4530 name pointer to the variable's name, starting with c or m
4532 Returns the pointer to variable's tree node
4536 acl_var_create(uschar * name)
4538 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4539 if (!(node = tree_search(*root, name)))
4541 node = store_get(sizeof(tree_node) + Ustrlen(name), is_tainted(name));
4542 Ustrcpy(node->name, name);
4543 (void)tree_insertnode(root, node);
4545 node->data.ptr = NULL;
4551 /*************************************************
4552 * Write an ACL variable in spool format *
4553 *************************************************/
4555 /* This function is used as a callback for tree_walk when writing variables to
4556 the spool file. To retain spool file compatibility, what is written is -aclc or
4557 -aclm followed by the rest of the name and the data length, space separated,
4558 then the value itself, starting on a new line, and terminated by an additional
4559 newline. When we had only numbered ACL variables, the first line might look
4560 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4564 name of the variable
4565 value of the variable
4566 ctx FILE pointer (as a void pointer)
4572 acl_var_write(uschar *name, uschar *value, void *ctx)
4574 FILE *f = (FILE *)ctx;
4575 if (is_tainted(value)) putc('-', f);
4576 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);