1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Code for handling Access Control Lists (ACLs) */
13 /* Default callout timeout */
15 #define CALLOUT_TIMEOUT_DEFAULT 30
17 /* ACL verb codes - keep in step with the table of verbs that follows */
19 enum { ACL_ACCEPT, ACL_DEFER, ACL_DENY, ACL_DISCARD, ACL_DROP, ACL_REQUIRE,
24 static uschar *verbs[] = {
25 [ACL_ACCEPT] = US"accept",
26 [ACL_DEFER] = US"defer",
27 [ACL_DENY] = US"deny",
28 [ACL_DISCARD] = US"discard",
29 [ACL_DROP] = US"drop",
30 [ACL_REQUIRE] = US"require",
34 /* For each verb, the conditions for which "message" or "log_message" are used
35 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
36 "accept", the FAIL case is used only after "endpass", but that is selected in
39 static int msgcond[] = {
40 [ACL_ACCEPT] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
41 [ACL_DEFER] = BIT(OK),
43 [ACL_DISCARD] = BIT(OK) | BIT(FAIL) | BIT(FAIL_DROP),
45 [ACL_REQUIRE] = BIT(FAIL) | BIT(FAIL_DROP),
49 /* ACL condition and modifier codes - keep in step with the table that
56 #ifdef EXPERIMENTAL_BRIGHTMAIL
62 #ifdef EXPERIMENTAL_DCC
65 #ifdef WITH_CONTENT_SCAN
73 #ifdef EXPERIMENTAL_DMARC
83 ACLC_LOG_REJECT_TARGET,
85 #ifdef WITH_CONTENT_SCAN
89 #ifdef WITH_CONTENT_SCAN
95 #ifdef WITH_CONTENT_SCAN
102 #ifdef WITH_CONTENT_SCAN
112 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
113 "message", "log_message", "log_reject_target", "logwrite", "queue" and "set" are
114 modifiers that look like conditions but always return TRUE. They are used for
115 their side effects. */
117 typedef struct condition_def {
120 /* Flag to indicate the condition/modifier has a string expansion done
121 at the outer level. In the other cases, expansion already occurs in the
122 checking functions. */
123 BOOL expand_at_top:1;
127 /* Bit map vector of which conditions and modifiers are not allowed at certain
128 times. For each condition and modifier, there's a bitmap of dis-allowed times.
129 For some, it is easier to specify the negation of a small number of allowed
135 static condition_def conditions[] = {
136 [ACLC_ACL] = { US"acl", FALSE, FALSE, 0 },
138 [ACLC_ADD_HEADER] = { US"add_header", TRUE, TRUE,
140 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
141 ACL_BIT_PREDATA | ACL_BIT_DATA |
145 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
147 ACL_BIT_NOTSMTP_START),
150 [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE,
151 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
152 ACL_BIT_CONNECT | ACL_BIT_HELO,
154 #ifdef EXPERIMENTAL_BRIGHTMAIL
155 [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE,
157 ACL_BIT_CONNECT | ACL_BIT_HELO |
158 ACL_BIT_DATA | ACL_BIT_MIME |
159 # ifndef DISABLE_PRDR
162 ACL_BIT_ETRN | ACL_BIT_EXPN |
164 ACL_BIT_MAIL | ACL_BIT_STARTTLS |
165 ACL_BIT_VRFY | ACL_BIT_PREDATA |
166 ACL_BIT_NOTSMTP_START,
169 [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 },
170 [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 },
172 /* Certain types of control are always allowed, so we let it through
173 always and check in the control processing itself. */
174 [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 },
176 #ifdef EXPERIMENTAL_DCC
177 [ACLC_DCC] = { US"dcc", TRUE, FALSE,
180 # ifndef DISABLE_PRDR
186 #ifdef WITH_CONTENT_SCAN
187 [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
190 [ACLC_DELAY] = { US"delay", TRUE, TRUE, ACL_BIT_NOTQUIT },
192 [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
193 [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DKIM },
195 #ifdef EXPERIMENTAL_DMARC
196 [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~ACL_BIT_DATA },
199 /* Explicit key lookups can be made in non-smtp ACLs so pass
200 always and check in the verify processing itself. */
201 [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 },
203 [ACLC_DOMAINS] = { US"domains", FALSE, FALSE,
205 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
211 [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE,
212 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START |
216 [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 },
218 [ACLC_HOSTS] = { US"hosts", FALSE, FALSE,
219 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
221 [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE,
223 ~(ACL_BIT_RCPT | ACL_BIT_VRFY
230 [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 },
231 [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 },
232 [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 },
234 #ifdef WITH_CONTENT_SCAN
235 [ACLC_MALWARE] = { US"malware", TRUE, FALSE,
238 # ifndef DISABLE_PRDR
245 [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 },
246 #ifdef WITH_CONTENT_SCAN
247 [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~ACL_BIT_MIME },
250 [ACLC_QUEUE] = { US"queue", TRUE, TRUE,
258 [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 },
259 [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~ACL_BIT_RCPT },
261 #ifdef WITH_CONTENT_SCAN
262 [ACLC_REGEX] = { US"regex", TRUE, FALSE,
265 # ifndef DISABLE_PRDR
273 [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE,
275 ~(ACL_BIT_MAIL|ACL_BIT_RCPT |
276 ACL_BIT_PREDATA | ACL_BIT_DATA |
280 ACL_BIT_MIME | ACL_BIT_NOTSMTP |
281 ACL_BIT_NOTSMTP_START),
283 [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE,
284 ACL_BIT_AUTH | ACL_BIT_CONNECT |
286 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
287 ACL_BIT_ETRN | ACL_BIT_EXPN |
288 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
290 [ACLC_SENDERS] = { US"senders", FALSE, FALSE,
291 ACL_BIT_AUTH | ACL_BIT_CONNECT |
293 ACL_BIT_MAILAUTH | ACL_BIT_QUIT |
294 ACL_BIT_ETRN | ACL_BIT_EXPN |
295 ACL_BIT_STARTTLS | ACL_BIT_VRFY,
298 [ACLC_SET] = { US"set", TRUE, TRUE, 0 },
300 #ifdef WITH_CONTENT_SCAN
301 [ACLC_SPAM] = { US"spam", TRUE, FALSE,
302 (unsigned int) ~(ACL_BIT_DATA |
303 # ifndef DISABLE_PRDR
310 [ACLC_SPF] = { US"spf", TRUE, FALSE,
311 ACL_BIT_AUTH | ACL_BIT_CONNECT |
312 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
313 ACL_BIT_ETRN | ACL_BIT_EXPN |
314 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
315 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
317 [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE,
318 ACL_BIT_AUTH | ACL_BIT_CONNECT |
319 ACL_BIT_HELO | ACL_BIT_MAILAUTH |
320 ACL_BIT_ETRN | ACL_BIT_EXPN |
321 ACL_BIT_STARTTLS | ACL_BIT_VRFY |
322 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START,
325 [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 },
327 /* Certain types of verify are always allowed, so we let it through
328 always and check in the verify function itself */
329 [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 },
334 /* Return values from decode_control(); used as index so keep in step
335 with the controls_list table that follows! */
338 CONTROL_AUTH_UNADVERTISED,
339 #ifdef EXPERIMENTAL_BRIGHTMAIL
342 CONTROL_CASEFUL_LOCAL_PART,
343 CONTROL_CASELOWER_LOCAL_PART,
344 CONTROL_CUTTHROUGH_DELIVERY,
349 #ifdef EXPERIMENTAL_DMARC
350 CONTROL_DMARC_VERIFY,
351 CONTROL_DMARC_FORENSIC,
354 CONTROL_ENFORCE_SYNC,
355 CONTROL_ERROR, /* pseudo-value for decode errors */
360 CONTROL_NO_CALLOUT_FLUSH,
361 CONTROL_NO_DELAY_FLUSH,
362 CONTROL_NO_ENFORCE_SYNC,
363 #ifdef WITH_CONTENT_SCAN
364 CONTROL_NO_MBOX_UNSPOOL,
366 CONTROL_NO_MULTILINE,
367 CONTROL_NO_PIPELINING,
371 CONTROL_SUPPRESS_LOCAL_FIXUPS,
373 CONTROL_UTF8_DOWNCONVERT,
379 /* Structure listing various control arguments, with their characteristics.
380 For each control, there's a bitmap of dis-allowed times. For some, it is easier
381 to specify the negation of a small number of allowed times. */
383 typedef struct control_def {
385 BOOL has_option; /* Has /option(s) following */
386 unsigned forbids; /* bitmap of dis-allowed times */
389 static control_def controls_list[] = {
390 /* name has_option forbids */
391 [CONTROL_AUTH_UNADVERTISED] =
392 { US"allow_auth_unadvertised", FALSE,
394 ~(ACL_BIT_CONNECT | ACL_BIT_HELO)
396 #ifdef EXPERIMENTAL_BRIGHTMAIL
398 { US"bmi_run", FALSE, 0 },
400 [CONTROL_CASEFUL_LOCAL_PART] =
401 { US"caseful_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
402 [CONTROL_CASELOWER_LOCAL_PART] =
403 { US"caselower_local_part", FALSE, (unsigned) ~ACL_BIT_RCPT },
404 [CONTROL_CUTTHROUGH_DELIVERY] =
405 { US"cutthrough_delivery", TRUE, 0 },
407 { US"debug", TRUE, 0 },
410 [CONTROL_DKIM_VERIFY] =
411 { US"dkim_disable_verify", FALSE,
412 ACL_BIT_DATA | ACL_BIT_NOTSMTP |
413 # ifndef DISABLE_PRDR
416 ACL_BIT_NOTSMTP_START
420 #ifdef EXPERIMENTAL_DMARC
421 [CONTROL_DMARC_VERIFY] =
422 { US"dmarc_disable_verify", FALSE,
423 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
425 [CONTROL_DMARC_FORENSIC] =
426 { US"dmarc_enable_forensic", FALSE,
427 ACL_BIT_DATA | ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
433 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START | ACL_BIT_NOTQUIT
435 [CONTROL_ENFORCE_SYNC] =
436 { US"enforce_sync", FALSE,
437 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
440 /* Pseudo-value for decode errors */
442 { US"error", FALSE, 0 },
444 [CONTROL_FAKEDEFER] =
445 { US"fakedefer", TRUE,
447 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
448 ACL_BIT_PREDATA | ACL_BIT_DATA |
454 [CONTROL_FAKEREJECT] =
455 { US"fakereject", TRUE,
457 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
458 ACL_BIT_PREDATA | ACL_BIT_DATA |
467 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
468 ACL_BIT_PREDATA | ACL_BIT_DATA |
469 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
470 ACL_BIT_NOTSMTP | ACL_BIT_MIME)
473 [CONTROL_NO_CALLOUT_FLUSH] =
474 { US"no_callout_flush", FALSE,
475 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
477 [CONTROL_NO_DELAY_FLUSH] =
478 { US"no_delay_flush", FALSE,
479 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
482 [CONTROL_NO_ENFORCE_SYNC] =
483 { US"no_enforce_sync", FALSE,
484 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
486 #ifdef WITH_CONTENT_SCAN
487 [CONTROL_NO_MBOX_UNSPOOL] =
488 { US"no_mbox_unspool", FALSE,
490 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
491 ACL_BIT_PREDATA | ACL_BIT_DATA |
492 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
496 [CONTROL_NO_MULTILINE] =
497 { US"no_multiline_responses", FALSE,
498 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
500 [CONTROL_NO_PIPELINING] =
501 { US"no_pipelining", FALSE,
502 ACL_BIT_NOTSMTP | ACL_BIT_NOTSMTP_START
505 [CONTROL_QUEUE_ONLY] =
506 { US"queue_only", FALSE,
508 ~(ACL_BIT_MAIL | ACL_BIT_RCPT |
509 ACL_BIT_PREDATA | ACL_BIT_DATA |
510 // ACL_BIT_PRDR| /* Not allow one user to freeze for all */
511 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));
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));
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 &&
870 Ustrncmp(s, "acl_m", 5) != 0)
872 *error = string_sprintf("invalid variable name after \"set\" in ACL "
873 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
878 if (!isdigit(*endptr) && *endptr != '_')
880 *error = string_sprintf("invalid variable name after \"set\" in ACL "
881 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
886 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
888 if (!isalnum(*endptr) && *endptr != '_')
890 *error = string_sprintf("invalid character \"%c\" in variable name "
891 "in ACL modifier \"set %s\"", *endptr, s);
897 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
899 while (isspace(*s)) s++;
902 /* For "set", we are now positioned for the data. For the others, only
903 "endpass" has no data */
905 if (c != ACLC_ENDPASS)
909 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
910 conditions[c].is_modifier ? US"modifier" : US"condition");
913 while (isspace(*s)) s++;
914 cond->arg = string_copy(s);
923 /*************************************************
924 * Set up added header line(s) *
925 *************************************************/
927 /* This function is called by the add_header modifier, and also from acl_warn()
928 to implement the now-deprecated way of adding header lines using "message" on a
929 "warn" verb. The argument is treated as a sequence of header lines which are
930 added to a chain, provided there isn't an identical one already there.
932 Argument: string of header lines
937 setup_header(const uschar *hstring)
940 int hlen = Ustrlen(hstring);
942 /* Ignore any leading newlines */
943 while (*hstring == '\n') hstring++, hlen--;
945 /* An empty string does nothing; ensure exactly one final newline. */
946 if (hlen <= 0) return;
947 if (hstring[--hlen] != '\n') /* no newline */
948 q = string_sprintf("%s\n", hstring);
949 else if (hstring[hlen-1] == '\n') /* double newline */
951 uschar * s = string_copy(hstring);
952 while(s[--hlen] == '\n')
959 /* Loop for multiple header lines, taking care about continuations */
961 for (p = q; *p; p = q)
965 int newtype = htype_add_bot;
966 header_line **hptr = &acl_added_headers;
968 /* Find next header line within the string */
972 q = Ustrchr(q, '\n'); /* we know there was a newline */
973 if (*++q != ' ' && *q != '\t') break;
976 /* If the line starts with a colon, interpret the instruction for where to
977 add it. This temporarily sets up a new type. */
981 if (strncmpic(p, US":after_received:", 16) == 0)
983 newtype = htype_add_rec;
986 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
988 newtype = htype_add_rfc;
991 else if (strncmpic(p, US":at_start:", 10) == 0)
993 newtype = htype_add_top;
996 else if (strncmpic(p, US":at_end:", 8) == 0)
998 newtype = htype_add_bot;
1001 while (*p == ' ' || *p == '\t') p++;
1004 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
1005 to the front of it. */
1007 for (s = p; s < q - 1; s++)
1008 if (*s == ':' || !isgraph(*s)) break;
1010 hdr = string_sprintf("%s%.*s", *s == ':' ? "" : "X-ACL-Warn: ", (int) (q - p), p);
1011 hlen = Ustrlen(hdr);
1013 /* See if this line has already been added */
1017 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1018 hptr = &(*hptr)->next;
1021 /* Add if not previously present */
1025 header_line *h = store_get(sizeof(header_line));
1038 /*************************************************
1039 * List the added header lines *
1040 *************************************************/
1046 for (header_line * h = acl_added_headers; h; h = h->next)
1049 if (h->text[i-1] == '\n') i--;
1050 g = string_append_listele_n(g, '\n', h->text, i);
1053 return g ? g->s : NULL;
1057 /*************************************************
1058 * Set up removed header line(s) *
1059 *************************************************/
1061 /* This function is called by the remove_header modifier. The argument is
1062 treated as a sequence of header names which are added to a colon separated
1063 list, provided there isn't an identical one already there.
1065 Argument: string of header names
1070 setup_remove_header(const uschar *hnames)
1073 acl_removed_headers = acl_removed_headers
1074 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1075 : string_copy(hnames);
1080 /*************************************************
1082 *************************************************/
1084 /* This function is called when a WARN verb's conditions are true. It adds to
1085 the message's headers, and/or writes information to the log. In each case, this
1086 only happens once (per message for headers, per connection for log).
1088 ** NOTE: The header adding action using the "message" setting is historic, and
1089 its use is now deprecated. The new add_header modifier should be used instead.
1092 where ACL_WHERE_xxxx indicating which ACL this is
1093 user_message message for adding to headers
1094 log_message message for logging, if different
1100 acl_warn(int where, uschar *user_message, uschar *log_message)
1102 if (log_message != NULL && log_message != user_message)
1105 string_item *logged;
1107 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1108 string_printing(log_message));
1110 /* If a sender verification has failed, and the log message is "sender verify
1111 failed", add the failure message. */
1113 if (sender_verified_failed != NULL &&
1114 sender_verified_failed->message != NULL &&
1115 strcmpic(log_message, US"sender verify failed") == 0)
1116 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1118 /* Search previously logged warnings. They are kept in malloc
1119 store so they can be freed at the start of a new message. */
1121 for (logged = acl_warn_logged; logged; logged = logged->next)
1122 if (Ustrcmp(logged->text, text) == 0) break;
1126 int length = Ustrlen(text) + 1;
1127 log_write(0, LOG_MAIN, "%s", text);
1128 logged = store_malloc(sizeof(string_item) + length);
1129 logged->text = US logged + sizeof(string_item);
1130 memcpy(logged->text, text, length);
1131 logged->next = acl_warn_logged;
1132 acl_warn_logged = logged;
1136 /* If there's no user message, we are done. */
1138 if (!user_message) return;
1140 /* If this isn't a message ACL, we can't do anything with a user message.
1143 if (where > ACL_WHERE_NOTSMTP)
1145 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1146 "found in a non-message (%s) ACL: cannot specify header lines here: "
1147 "message ignored", acl_wherenames[where]);
1151 /* The code for setting up header lines is now abstracted into a separate
1152 function so that it can be used for the add_header modifier as well. */
1154 setup_header(user_message);
1159 /*************************************************
1160 * Verify and check reverse DNS *
1161 *************************************************/
1163 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1164 address if this has not yet been done. The host_name_lookup() function checks
1165 that one of these names resolves to an address list that contains the client IP
1166 address, so we don't actually have to do the check here.
1169 user_msgptr pointer for user message
1170 log_msgptr pointer for log message
1172 Returns: OK verification condition succeeded
1173 FAIL verification failed
1174 DEFER there was a problem verifying
1178 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1182 user_msgptr = user_msgptr; /* stop compiler warning */
1184 /* Previous success */
1186 if (sender_host_name != NULL) return OK;
1188 /* Previous failure */
1190 if (host_lookup_failed)
1192 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1196 /* Need to do a lookup */
1199 debug_printf_indent("looking up host name to force name/address consistency check\n");
1201 if ((rc = host_name_lookup()) != OK)
1203 *log_msgptr = rc == DEFER
1204 ? US"host lookup deferred for reverse lookup check"
1205 : string_sprintf("host lookup failed for reverse lookup check%s",
1207 return rc; /* DEFER or FAIL */
1210 host_build_sender_fullhost();
1216 /*************************************************
1217 * Check client IP address matches CSA target *
1218 *************************************************/
1220 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1221 response for address records belonging to the CSA target hostname. The section
1222 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1223 If one of the addresses matches the client's IP address, then the client is
1224 authorized by CSA. If there are target IP addresses but none of them match
1225 then the client is using an unauthorized IP address. If there are no target IP
1226 addresses then the client cannot be using an authorized IP address. (This is
1227 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1230 dnsa the DNS answer block
1231 dnss a DNS scan block for us to use
1232 reset option specifying what portion to scan, as described above
1233 target the target hostname to use for matching RR names
1235 Returns: CSA_OK successfully authorized
1236 CSA_FAIL_MISMATCH addresses found but none matched
1237 CSA_FAIL_NOADDR no target addresses found
1241 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1244 int rc = CSA_FAIL_NOADDR;
1246 for (dns_record * rr = dns_next_rr(dnsa, dnss, reset);
1248 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1250 /* Check this is an address RR for the target hostname. */
1254 && rr->type != T_AAAA
1258 if (strcmpic(target, rr->name) != 0) continue;
1260 rc = CSA_FAIL_MISMATCH;
1262 /* Turn the target address RR into a list of textual IP addresses and scan
1263 the list. There may be more than one if it is an A6 RR. */
1265 for (dns_address * da = dns_address_from_rr(dnsa, rr); da; da = da->next)
1267 /* If the client IP address matches the target IP address, it's good! */
1269 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1271 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1275 /* If we found some target addresses but none of them matched, the client is
1276 using an unauthorized IP address, otherwise the target has no authorized IP
1284 /*************************************************
1285 * Verify Client SMTP Authorization *
1286 *************************************************/
1288 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1289 to find the CSA SRV record corresponding to the domain argument, or
1290 $sender_helo_name if no argument is provided. It then checks that the
1291 client is authorized, and that its IP address corresponds to the SRV
1292 target's address by calling acl_verify_csa_address() above. The address
1293 should have been returned in the DNS response's ADDITIONAL section, but if
1294 not we perform another DNS lookup to get it.
1297 domain pointer to optional parameter following verify = csa
1299 Returns: CSA_UNKNOWN no valid CSA record found
1300 CSA_OK successfully authorized
1301 CSA_FAIL_* client is definitely not authorized
1302 CSA_DEFER_* there was a DNS problem
1306 acl_verify_csa(const uschar *domain)
1309 const uschar *found;
1310 int priority, weight, port;
1317 /* Work out the domain we are using for the CSA lookup. The default is the
1318 client's HELO domain. If the client has not said HELO, use its IP address
1319 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1321 while (isspace(*domain) && *domain != '\0') ++domain;
1322 if (*domain == '\0') domain = sender_helo_name;
1323 if (domain == NULL) domain = sender_host_address;
1324 if (sender_host_address == NULL) return CSA_UNKNOWN;
1326 /* If we have an address literal, strip off the framing ready for turning it
1327 into a domain. The framing consists of matched square brackets possibly
1328 containing a keyword and a colon before the actual IP address. */
1330 if (domain[0] == '[')
1332 const uschar *start = Ustrchr(domain, ':');
1333 if (start == NULL) start = domain;
1334 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1337 /* Turn domains that look like bare IP addresses into domains in the reverse
1338 DNS. This code also deals with address literals and $sender_host_address. It's
1339 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1340 address literals, but it's probably the most friendly thing to do. This is an
1341 extension to CSA, so we allow it to be turned off for proper conformance. */
1343 if (string_is_ip_address(domain, NULL) != 0)
1345 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1346 dns_build_reverse(domain, target);
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));
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, ~0, FALSE, 0 },
1511 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1512 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1513 { US"csa", VERIFY_CSA, ~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, TRUE, 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 if ((rc = verify_check_notblind()) != OK)
1717 *log_msgptr = string_sprintf("bcc recipient detected");
1718 if (smtp_return_error_details)
1719 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1723 /* The remaining verification tests check recipient and sender addresses,
1724 either from the envelope or from the header. There are a number of
1725 slash-separated options that are common to all of them. */
1727 case VERIFY_HDR_SNDR:
1728 verify_header_sender = TRUE;
1732 /* In the case of a sender, this can optionally be followed by an address to use
1733 in place of the actual sender (rare special-case requirement). */
1737 verify_sender_address = sender_address;
1740 while (isspace(*s)) s++;
1741 if (*s++ != '=') goto BAD_VERIFY;
1742 while (isspace(*s)) s++;
1743 verify_sender_address = string_copy(s);
1754 /* Remaining items are optional; they apply to sender and recipient
1755 verification, including "header sender" verification. */
1757 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1759 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1760 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1761 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1763 /* These two old options are left for backwards compatibility */
1765 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1767 callout_defer_ok = TRUE;
1768 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1771 else if (strcmpic(ss, US"check_postmaster") == 0)
1774 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1777 /* The callout option has a number of sub-options, comma separated */
1779 else if (strncmpic(ss, US"callout", 7) == 0)
1781 callout = CALLOUT_TIMEOUT_DEFAULT;
1785 while (isspace(*ss)) ss++;
1788 const uschar * sublist = ss;
1793 while (isspace(*sublist)) sublist++;
1794 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1797 double period = 1.0F;
1799 for (op= callout_opt_list; op->name; op++)
1800 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1803 verify_options |= op->flag;
1806 opt += Ustrlen(op->name);
1807 while (isspace(*opt)) opt++;
1810 *log_msgptr = string_sprintf("'=' expected after "
1811 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1814 while (isspace(*opt)) opt++;
1816 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1818 *log_msgptr = string_sprintf("bad time value in ACL condition "
1819 "\"verify %s\"", arg);
1825 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1826 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1827 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1828 case CALLOUT_MAILFROM:
1829 if (!verify_header_sender)
1831 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1832 "callout option only for verify=header_sender (detected in ACL "
1833 "condition \"%s\")", arg);
1836 se_mailfrom = string_copy(opt);
1838 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1839 case CALLOUT_MAXWAIT: callout_overall = period; break;
1840 case CALLOUT_CONNECT: callout_connect = period; break;
1841 case CALLOUT_TIME: callout = period; break;
1847 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1848 "ACL condition \"%s\"", arg);
1854 /* Option not recognized */
1858 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1859 "condition \"verify %s\"", ss, arg);
1864 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1865 (vopt_callout_recipsender|vopt_callout_recippmaster))
1867 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1868 "for a recipient callout";
1872 /* Handle sender-in-header verification. Default the user message to the log
1873 message if giving out verification details. */
1875 if (verify_header_sender)
1879 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1880 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1883 *basic_errno = verrno;
1884 if (smtp_return_error_details)
1886 if (!*user_msgptr && *log_msgptr)
1887 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1888 if (rc == DEFER) f.acl_temp_details = TRUE;
1893 /* Handle a sender address. The default is to verify *the* sender address, but
1894 optionally a different address can be given, for special requirements. If the
1895 address is empty, we are dealing with a bounce message that has no sender, so
1896 we cannot do any checking. If the real sender address gets rewritten during
1897 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1898 during message reception.
1900 A list of verified "sender" addresses is kept to try to avoid doing to much
1901 work repetitively when there are multiple recipients in a message and they all
1902 require sender verification. However, when callouts are involved, it gets too
1903 complicated because different recipients may require different callout options.
1904 Therefore, we always do a full sender verify when any kind of callout is
1905 specified. Caching elsewhere, for instance in the DNS resolver and in the
1906 callout handling, should ensure that this is not terribly inefficient. */
1908 else if (verify_sender_address)
1910 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1912 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1913 "sender verify callout";
1917 sender_vaddr = verify_checked_sender(verify_sender_address);
1918 if (sender_vaddr != NULL && /* Previously checked */
1919 callout <= 0) /* No callout needed this time */
1921 /* If the "routed" flag is set, it means that routing worked before, so
1922 this check can give OK (the saved return code value, if set, belongs to a
1923 callout that was done previously). If the "routed" flag is not set, routing
1924 must have failed, so we use the saved return code. */
1926 if (testflag(sender_vaddr, af_verify_routed))
1930 rc = sender_vaddr->special_action;
1931 *basic_errno = sender_vaddr->basic_errno;
1933 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1936 /* Do a new verification, and cache the result. The cache is used to avoid
1937 verifying the sender multiple times for multiple RCPTs when callouts are not
1938 specified (see comments above).
1940 The cache is also used on failure to give details in response to the first
1941 RCPT that gets bounced for this reason. However, this can be suppressed by
1942 the no_details option, which sets the flag that says "this detail has already
1943 been sent". The cache normally contains just one address, but there may be
1944 more in esoteric circumstances. */
1949 uschar *save_address_data = deliver_address_data;
1951 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1953 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1955 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1956 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1959 if (no_details) setflag(sender_vaddr, af_sverify_told);
1960 if (verify_sender_address[0] != 0)
1962 /* If this is the real sender address, save the unrewritten version
1963 for use later in receive. Otherwise, set a flag so that rewriting the
1964 sender in verify_address() does not update sender_address. */
1966 if (verify_sender_address == sender_address)
1967 sender_address_unrewritten = sender_address;
1969 verify_options |= vopt_fake_sender;
1971 if (success_on_redirect)
1972 verify_options |= vopt_success_on_redirect;
1974 /* The recipient, qualify, and expn options are never set in
1977 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1978 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1980 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
1983 *basic_errno = sender_vaddr->basic_errno;
1987 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1988 debug_printf_indent("sender %s verified ok as %s\n",
1989 verify_sender_address, sender_vaddr->address);
1991 debug_printf_indent("sender %s verified ok\n",
1992 verify_sender_address);
1996 rc = OK; /* Null sender */
1998 /* Cache the result code */
2000 if (routed) setflag(sender_vaddr, af_verify_routed);
2001 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2002 sender_vaddr->special_action = rc;
2003 sender_vaddr->next = sender_verified_list;
2004 sender_verified_list = sender_vaddr;
2006 /* Restore the recipient address data, which might have been clobbered by
2007 the sender verification. */
2009 deliver_address_data = save_address_data;
2012 /* Put the sender address_data value into $sender_address_data */
2014 sender_address_data = sender_vaddr->prop.address_data;
2017 /* A recipient address just gets a straightforward verify; again we must handle
2018 the DEFER overrides. */
2024 if (success_on_redirect)
2025 verify_options |= vopt_success_on_redirect;
2027 /* We must use a copy of the address for verification, because it might
2031 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2032 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2033 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2035 *basic_errno = addr2.basic_errno;
2036 *log_msgptr = addr2.message;
2037 *user_msgptr = (addr2.user_message != NULL)?
2038 addr2.user_message : addr2.message;
2040 /* Allow details for temporary error if the address is so flagged. */
2041 if (testflag((&addr2), af_pass_message)) f.acl_temp_details = TRUE;
2043 /* Make $address_data visible */
2044 deliver_address_data = addr2.prop.address_data;
2047 /* We have a result from the relevant test. Handle defer overrides first. */
2049 if (rc == DEFER && (defer_ok ||
2050 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2052 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2053 defer_ok? "defer_ok" : "callout_defer_ok");
2057 /* If we've failed a sender, set up a recipient message, and point
2058 sender_verified_failed to the address item that actually failed. */
2060 if (rc != OK && verify_sender_address != NULL)
2063 *log_msgptr = *user_msgptr = US"Sender verify failed";
2064 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2065 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2068 *log_msgptr = US"Could not complete sender verify callout";
2069 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2073 sender_verified_failed = sender_vaddr;
2076 /* Verifying an address messes up the values of $domain and $local_part,
2077 so reset them before returning if this is a RCPT ACL. */
2081 deliver_domain = addr->domain;
2082 deliver_localpart = addr->local_part;
2086 /* Syntax errors in the verify argument come here. */
2089 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2090 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2091 "or \"reverse_host_lookup\" at start of ACL condition "
2092 "\"verify %s\"", arg);
2099 /*************************************************
2100 * Check argument for control= modifier *
2101 *************************************************/
2103 /* Called from acl_check_condition() below
2106 arg the argument string for control=
2107 pptr set to point to the terminating character
2108 where which ACL we are in
2109 log_msgptr for error messages
2111 Returns: CONTROL_xxx value
2115 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2120 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2121 || ( arg[len = Ustrlen((d = controls_list+idx)->name)] != 0
2122 && (!d->has_option || arg[len] != '/')
2125 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2126 return CONTROL_ERROR;
2136 /*************************************************
2137 * Return a ratelimit error *
2138 *************************************************/
2140 /* Called from acl_ratelimit() below
2143 log_msgptr for error messages
2144 format format string
2145 ... supplementary arguments
2151 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2155 string_cat(NULL, US"error in arguments to \"ratelimit\" condition: ");
2157 va_start(ap, format);
2158 g = string_vformat(g, TRUE, format, ap);
2161 gstring_reset_unused(g);
2162 *log_msgptr = string_from_gstring(g);
2169 /*************************************************
2170 * Handle rate limiting *
2171 *************************************************/
2173 /* Called by acl_check_condition() below to calculate the result
2174 of the ACL ratelimit condition.
2176 Note that the return value might be slightly unexpected: if the
2177 sender's rate is above the limit then the result is OK. This is
2178 similar to the dnslists condition, and is so that you can write
2179 ACL clauses like: defer ratelimit = 15 / 1h
2182 arg the option string for ratelimit=
2183 where ACL_WHERE_xxxx indicating which ACL this is
2184 log_msgptr for error messages
2186 Returns: OK - Sender's rate is above limit
2187 FAIL - Sender's rate is below limit
2188 DEFER - Problem opening ratelimit database
2189 ERROR - Syntax error in options.
2193 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2195 double limit, period, count;
2198 uschar *unique = NULL;
2200 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2201 BOOL noupdate = FALSE, badacl = FALSE;
2202 int mode = RATE_PER_WHAT;
2204 tree_node **anchor, *t;
2205 open_db dbblock, *dbm;
2207 dbdata_ratelimit *dbd;
2208 dbdata_ratelimit_unique *dbdb;
2211 /* Parse the first two options and record their values in expansion
2212 variables. These variables allow the configuration to have informative
2213 error messages based on rate limits obtained from a table lookup. */
2215 /* First is the maximum number of messages per period / maximum burst
2216 size, which must be greater than or equal to zero. Zero is useful for
2217 rate measurement as opposed to rate limiting. */
2219 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2220 return ratelimit_error(log_msgptr, "sender rate limit not set");
2222 limit = Ustrtod(sender_rate_limit, &ss);
2223 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2224 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2225 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2227 if (limit < 0.0 || *ss != '\0')
2228 return ratelimit_error(log_msgptr,
2229 "\"%s\" is not a positive number", sender_rate_limit);
2231 /* Second is the rate measurement period / exponential smoothing time
2232 constant. This must be strictly greater than zero, because zero leads to
2233 run-time division errors. */
2235 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2236 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2238 return ratelimit_error(log_msgptr,
2239 "\"%s\" is not a time value", sender_rate_period);
2241 /* By default we are counting one of something, but the per_rcpt,
2242 per_byte, and count options can change this. */
2246 /* Parse the other options. */
2248 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)))
2250 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2251 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2252 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2253 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2254 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2255 else if (strcmpic(ss, US"per_conn") == 0)
2257 RATE_SET(mode, PER_CONN);
2258 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2261 else if (strcmpic(ss, US"per_mail") == 0)
2263 RATE_SET(mode, PER_MAIL);
2264 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2266 else if (strcmpic(ss, US"per_rcpt") == 0)
2268 /* If we are running in the RCPT ACL, then we'll count the recipients
2269 one by one, but if we are running when we have accumulated the whole
2270 list then we'll add them all in one batch. */
2271 if (where == ACL_WHERE_RCPT)
2272 RATE_SET(mode, PER_RCPT);
2273 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2274 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2275 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2276 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2278 else if (strcmpic(ss, US"per_byte") == 0)
2280 /* If we have not yet received the message data and there was no SIZE
2281 declaration on the MAIL command, then it's safe to just use a value of
2282 zero and let the recorded rate decay as if nothing happened. */
2283 RATE_SET(mode, PER_MAIL);
2284 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2285 else count = message_size < 0 ? 0.0 : (double)message_size;
2287 else if (strcmpic(ss, US"per_addr") == 0)
2289 RATE_SET(mode, PER_RCPT);
2290 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2291 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2293 else if (strncmpic(ss, US"count=", 6) == 0)
2296 count = Ustrtod(ss+6, &e);
2297 if (count < 0.0 || *e != '\0')
2298 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2300 else if (strncmpic(ss, US"unique=", 7) == 0)
2301 unique = string_copy(ss + 7);
2303 key = string_copy(ss);
2305 key = string_sprintf("%s/%s", key, ss);
2308 /* Sanity check. When the badacl flag is set the update mode must either
2309 be readonly (which is the default if it is omitted) or, for backwards
2310 compatibility, a combination of noupdate and strict or leaky. */
2312 if (mode == RATE_PER_CLASH)
2313 return ratelimit_error(log_msgptr, "conflicting per_* options");
2314 if (leaky + strict + readonly > 1)
2315 return ratelimit_error(log_msgptr, "conflicting update modes");
2316 if (badacl && (leaky || strict) && !noupdate)
2317 return ratelimit_error(log_msgptr,
2318 "\"%s\" must not have /leaky or /strict option, or cannot be used in %s ACL",
2319 ratelimit_option_string[mode], acl_wherenames[where]);
2321 /* Set the default values of any unset options. In readonly mode we
2322 perform the rate computation without any increment so that its value
2323 decays to eventually allow over-limit senders through. */
2325 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2326 if (badacl) readonly = TRUE;
2327 if (readonly) count = 0.0;
2328 if (!strict && !readonly) leaky = TRUE;
2329 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2331 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2332 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2333 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2334 are added to the key because they alter the meaning of the stored data. */
2337 key = !sender_host_address ? US"" : sender_host_address;
2339 key = string_sprintf("%s/%s/%s%s",
2341 ratelimit_option_string[mode],
2342 unique == NULL ? "" : "unique/",
2346 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2348 /* See if we have already computed the rate by looking in the relevant tree.
2349 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2350 pool so that they survive across resets. In readonly mode we only remember the
2351 result for the rest of this command in case a later command changes it. After
2352 this bit of logic the code is independent of the per_* mode. */
2354 old_pool = store_pool;
2357 anchor = &ratelimiters_cmd;
2361 anchor = &ratelimiters_conn;
2362 store_pool = POOL_PERM;
2366 case RATE_PER_ALLRCPTS:
2367 anchor = &ratelimiters_mail;
2372 anchor = &ratelimiters_cmd;
2375 anchor = NULL; /* silence an "unused" complaint */
2376 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2377 "internal ACL error: unknown ratelimit mode %d", mode);
2381 if ((t = tree_search(*anchor, key)))
2384 /* The following few lines duplicate some of the code below. */
2385 rc = (dbd->rate < limit)? FAIL : OK;
2386 store_pool = old_pool;
2387 sender_rate = string_sprintf("%.1f", dbd->rate);
2389 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2393 /* We aren't using a pre-computed rate, so get a previously recorded rate
2394 from the database, which will be updated and written back if required. */
2396 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE)))
2398 store_pool = old_pool;
2400 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2401 *log_msgptr = US"ratelimit database not available";
2404 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2407 gettimeofday(&tv, NULL);
2411 /* Locate the basic ratelimit block inside the DB data. */
2412 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2415 /* Forget the old Bloom filter if it is too old, so that we count each
2416 repeating event once per period. We don't simply clear and re-use the old
2417 filter because we want its size to change if the limit changes. Note that
2418 we keep the dbd pointer for copying the rate into the new data block. */
2420 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2422 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2428 if(unique && dbdb_size < sizeof(*dbdb))
2430 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2435 /* Allocate a new data block if the database lookup failed
2436 or the Bloom filter passed its age limit. */
2442 /* No Bloom filter. This basic ratelimit block is initialized below. */
2443 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2444 dbdb_size = sizeof(*dbd);
2445 dbdb = store_get(dbdb_size);
2450 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2452 /* See the long comment below for an explanation of the magic number 2.
2453 The filter has a minimum size in case the rate limit is very small;
2454 this is determined by the definition of dbdata_ratelimit_unique. */
2456 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2457 if (extra < 0) extra = 0;
2458 dbdb_size = sizeof(*dbdb) + extra;
2459 dbdb = store_get(dbdb_size);
2460 dbdb->bloom_epoch = tv.tv_sec;
2461 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2462 memset(dbdb->bloom, 0, dbdb->bloom_size);
2464 /* Preserve any basic ratelimit data (which is our longer-term memory)
2465 by copying it from the discarded block. */
2475 /* If we are counting unique events, find out if this event is new or not.
2476 If the client repeats the event during the current period then it should be
2477 counted. We skip this code in readonly mode for efficiency, because any
2478 changes to the filter will be discarded and because count is already set to
2481 if (unique && !readonly)
2483 /* We identify unique events using a Bloom filter. (You can find my
2484 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2485 With the per_addr option, an "event" is a recipient address, though the
2486 user can use the unique option to define their own events. We only count
2487 an event if we have not seen it before.
2489 We size the filter according to the rate limit, which (in leaky mode)
2490 is the limit on the population of the filter. We allow 16 bits of space
2491 per entry (see the construction code above) and we set (up to) 8 of them
2492 when inserting an element (see the loop below). The probability of a false
2493 positive (an event we have not seen before but which we fail to count) is
2497 allzero = exp(-numhash * pop / size)
2498 = exp(-0.5 * pop / limit)
2499 fpr = pow(1 - allzero, numhash)
2501 For senders at the limit the fpr is 0.06% or 1 in 1700
2502 and for senders at half the limit it is 0.0006% or 1 in 170000
2504 In strict mode the Bloom filter can fill up beyond the normal limit, in
2505 which case the false positive rate will rise. This means that the
2506 measured rate for very fast senders can bogusly drop off after a while.
2508 At twice the limit, the fpr is 2.5% or 1 in 40
2509 At four times the limit, it is 31% or 1 in 3.2
2511 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2512 decay below the limit, and if this is more than one then the Bloom filter
2513 will be discarded before the decay gets that far. The false positive rate
2514 at this threshold is 9.3% or 1 in 10.7. */
2517 unsigned n, hash, hinc;
2521 /* Instead of using eight independent hash values, we combine two values
2522 using the formula h1 + n * h2. This does not harm the Bloom filter's
2523 performance, and means the amount of hash we need is independent of the
2524 number of bits we set in the filter. */
2526 md5_start(&md5info);
2527 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2528 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2529 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2531 /* Scan the bits corresponding to this event. A zero bit means we have
2532 not seen it before. Ensure all bits are set to record this event. */
2534 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2537 for (n = 0; n < 8; n++, hash += hinc)
2539 int bit = 1 << (hash % 8);
2540 int byte = (hash / 8) % dbdb->bloom_size;
2541 if ((dbdb->bloom[byte] & bit) == 0)
2543 dbdb->bloom[byte] |= bit;
2548 /* If this event has occurred before, do not count it. */
2552 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2556 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2559 /* If there was no previous ratelimit data block for this key, initialize
2560 the new one, otherwise update the block from the database. The initial rate
2561 is what would be computed by the code below for an infinite interval. */
2565 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2567 dbd->time_stamp = tv.tv_sec;
2568 dbd->time_usec = tv.tv_usec;
2573 /* The smoothed rate is computed using an exponentially weighted moving
2574 average adjusted for variable sampling intervals. The standard EWMA for
2575 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2576 where f() is the measured value and f'() is the smoothed value.
2578 Old data decays out of the smoothed value exponentially, such that data n
2579 samples old is multiplied by a^n. The exponential decay time constant p
2580 is defined such that data p samples old is multiplied by 1/e, which means
2581 that a = exp(-1/p). We can maintain the same time constant for a variable
2582 sampling interval i by using a = exp(-i/p).
2584 The rate we are measuring is messages per period, suitable for directly
2585 comparing with the limit. The average rate between now and the previous
2586 message is period / interval, which we feed into the EWMA as the sample.
2588 It turns out that the number of messages required for the smoothed rate
2589 to reach the limit when they are sent in a burst is equal to the limit.
2590 This can be seen by analysing the value of the smoothed rate after N
2591 messages sent at even intervals. Let k = (1 - a) * p/i
2593 rate_1 = (1 - a) * p/i + a * rate_0
2595 rate_2 = k + a * rate_1
2596 = k + a * k + a^2 * rate_0
2597 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2598 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2599 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2600 = rate_0 * a^N + p/i * (1 - a^N)
2602 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2604 rate_N = p/i + (rate_0 - p/i) * a^N
2605 a^N = (rate_N - p/i) / (rate_0 - p/i)
2606 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2607 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2609 Numerical analysis of the above equation, setting the computed rate to
2610 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2611 rates, p/i, the number of messages N = limit. So limit serves as both the
2612 maximum rate measured in messages per period, and the maximum number of
2613 messages that can be sent in a fast burst. */
2615 double this_time = (double)tv.tv_sec
2616 + (double)tv.tv_usec / 1000000.0;
2617 double prev_time = (double)dbd->time_stamp
2618 + (double)dbd->time_usec / 1000000.0;
2620 /* We must avoid division by zero, and deal gracefully with the clock going
2621 backwards. If we blunder ahead when time is in reverse then the computed
2622 rate will be bogus. To be safe we clamp interval to a very small number. */
2624 double interval = this_time - prev_time <= 0.0 ? 1e-9
2625 : this_time - prev_time;
2627 double i_over_p = interval / period;
2628 double a = exp(-i_over_p);
2630 /* Combine the instantaneous rate (period / interval) with the previous rate
2631 using the smoothing factor a. In order to measure sized events, multiply the
2632 instantaneous rate by the count of bytes or recipients etc. */
2634 dbd->time_stamp = tv.tv_sec;
2635 dbd->time_usec = tv.tv_usec;
2636 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2638 /* When events are very widely spaced the computed rate tends towards zero.
2639 Although this is accurate it turns out not to be useful for our purposes,
2640 especially when the first event after a long silence is the start of a spam
2641 run. A more useful model is that the rate for an isolated event should be the
2642 size of the event per the period size, ignoring the lack of events outside
2643 the current period and regardless of where the event falls in the period. So,
2644 if the interval was so long that the calculated rate is unhelpfully small, we
2645 re-initialize the rate. In the absence of higher-rate bursts, the condition
2646 below is true if the interval is greater than the period. */
2648 if (dbd->rate < count) dbd->rate = count;
2651 /* Clients sending at the limit are considered to be over the limit.
2652 This matters for edge cases such as a limit of zero, when the client
2653 should be completely blocked. */
2655 rc = dbd->rate < limit ? FAIL : OK;
2657 /* Update the state if the rate is low or if we are being strict. If we
2658 are in leaky mode and the sender's rate is too high, we do not update
2659 the recorded rate in order to avoid an over-aggressive sender's retry
2660 rate preventing them from getting any email through. If readonly is set,
2661 neither leaky nor strict are set, so we do not do any updates. */
2663 if ((rc == FAIL && leaky) || strict)
2665 dbfn_write(dbm, key, dbdb, dbdb_size);
2666 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2670 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2671 readonly? "readonly mode" : "over the limit, but leaky");
2676 /* Store the result in the tree for future reference. */
2678 t = store_get(sizeof(tree_node) + Ustrlen(key));
2680 Ustrcpy(t->name, key);
2681 (void)tree_insertnode(anchor, t);
2683 /* We create the formatted version of the sender's rate very late in
2684 order to ensure that it is done using the correct storage pool. */
2686 store_pool = old_pool;
2687 sender_rate = string_sprintf("%.1f", dbd->rate);
2690 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2697 /*************************************************
2698 * The udpsend ACL modifier *
2699 *************************************************/
2701 /* Called by acl_check_condition() below.
2704 arg the option string for udpsend=
2705 log_msgptr for error messages
2707 Returns: OK - Completed.
2708 DEFER - Problem with DNS lookup.
2709 ERROR - Syntax error in options.
2713 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2725 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2726 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2730 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2735 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2740 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2743 portnum = Ustrtol(portstr, &portend, 10);
2744 if (*portend != '\0')
2746 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2750 /* Make a single-item host list. */
2751 h = store_get(sizeof(host_item));
2752 memset(h, 0, sizeof(host_item));
2757 if (string_is_ip_address(hostname, NULL))
2758 h->address = hostname, r = HOST_FOUND;
2760 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2761 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2763 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2768 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2770 /*XXX this could better use sendto */
2771 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2772 1, NULL, &errstr, NULL);
2773 if (r < 0) goto defer;
2775 r = send(s, arg, len, 0);
2778 errstr = US strerror(errno);
2786 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2791 debug_printf_indent("udpsend %d bytes\n", r);
2796 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2802 /*************************************************
2803 * Handle conditions/modifiers on an ACL item *
2804 *************************************************/
2806 /* Called from acl_check() below.
2810 cb ACL condition block - if NULL, result is OK
2811 where where called from
2812 addr the address being checked for RCPT, or NULL
2813 level the nesting level
2814 epp pointer to pass back TRUE if "endpass" encountered
2815 (applies only to "accept" and "discard")
2816 user_msgptr user message pointer
2817 log_msgptr log message pointer
2818 basic_errno pointer to where to put verify error
2820 Returns: OK - all conditions are met
2821 DISCARD - an "acl" condition returned DISCARD - only allowed
2822 for "accept" or "discard" verbs
2823 FAIL - at least one condition fails
2824 FAIL_DROP - an "acl" condition returned FAIL_DROP
2825 DEFER - can't tell at the moment (typically, lookup defer,
2826 but can be temporary callout problem)
2827 ERROR - ERROR from nested ACL or expansion failure or other
2832 acl_check_condition(int verb, acl_condition_block *cb, int where,
2833 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2834 uschar **log_msgptr, int *basic_errno)
2836 uschar *user_message = NULL;
2837 uschar *log_message = NULL;
2839 #ifdef WITH_CONTENT_SCAN
2843 for (; cb; cb = cb->next)
2848 /* The message and log_message items set up messages to be used in
2849 case of rejection. They are expanded later. */
2851 if (cb->type == ACLC_MESSAGE)
2853 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2854 user_message = cb->arg;
2858 if (cb->type == ACLC_LOG_MESSAGE)
2860 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2861 log_message = cb->arg;
2865 /* The endpass "condition" just sets a flag to show it occurred. This is
2866 checked at compile time to be on an "accept" or "discard" item. */
2868 if (cb->type == ACLC_ENDPASS)
2874 /* For other conditions and modifiers, the argument is expanded now for some
2875 of them, but not for all, because expansion happens down in some lower level
2876 checking functions in some cases. */
2878 if (!conditions[cb->type].expand_at_top)
2880 else if (!(arg = expand_string(cb->arg)))
2882 if (f.expand_string_forcedfail) continue;
2883 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2884 cb->arg, expand_string_message);
2885 return f.search_find_defer ? DEFER : ERROR;
2888 /* Show condition, and expanded condition if it's different */
2893 debug_printf_indent("check %s%s %n",
2894 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2895 conditions[cb->type].name, &lhswidth);
2897 if (cb->type == ACLC_SET)
2899 #ifndef DISABLE_DKIM
2900 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2901 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2903 debug_printf("%s ", cb->u.varname);
2909 debug_printf("acl_%s ", cb->u.varname);
2910 lhswidth += 5 + Ustrlen(cb->u.varname);
2914 debug_printf("= %s\n", cb->arg);
2917 debug_printf("%.*s= %s\n", lhswidth,
2921 /* Check that this condition makes sense at this time */
2923 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2925 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2926 conditions[cb->type].is_modifier ? "use" : "test",
2927 conditions[cb->type].name, acl_wherenames[where]);
2931 /* Run the appropriate test for each condition, or take the appropriate
2932 action for the remaining modifiers. */
2936 case ACLC_ADD_HEADER:
2940 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2944 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2945 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2947 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2948 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2954 case ACLC_AUTHENTICATED:
2955 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
2956 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
2959 #ifdef EXPERIMENTAL_BRIGHTMAIL
2960 case ACLC_BMI_OPTIN:
2962 int old_pool = store_pool;
2963 store_pool = POOL_PERM;
2964 bmi_current_optin = string_copy(arg);
2965 store_pool = old_pool;
2970 case ACLC_CONDITION:
2971 /* The true/false parsing here should be kept in sync with that used in
2972 expand.c when dealing with ECOND_BOOL so that we don't have too many
2973 different definitions of what can be a boolean. */
2975 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
2976 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2977 rc = (Uatoi(arg) == 0)? FAIL : OK;
2979 rc = (strcmpic(arg, US"no") == 0 ||
2980 strcmpic(arg, US"false") == 0)? FAIL :
2981 (strcmpic(arg, US"yes") == 0 ||
2982 strcmpic(arg, US"true") == 0)? OK : DEFER;
2984 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2987 case ACLC_CONTINUE: /* Always succeeds */
2992 const uschar *p = NULL;
2993 control_type = decode_control(arg, &p, where, log_msgptr);
2995 /* Check if this control makes sense at this time */
2997 if (controls_list[control_type].forbids & (1 << where))
2999 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3000 controls_list[control_type].name, acl_wherenames[where]);
3004 switch(control_type)
3006 case CONTROL_AUTH_UNADVERTISED:
3007 f.allow_auth_unadvertised = TRUE;
3010 #ifdef EXPERIMENTAL_BRIGHTMAIL
3011 case CONTROL_BMI_RUN:
3016 #ifndef DISABLE_DKIM
3017 case CONTROL_DKIM_VERIFY:
3018 f.dkim_disable_verify = TRUE;
3019 #ifdef EXPERIMENTAL_DMARC
3020 /* Since DKIM was blocked, skip DMARC too */
3021 f.dmarc_disable_verify = TRUE;
3022 f.dmarc_enable_forensic = FALSE;
3027 #ifdef EXPERIMENTAL_DMARC
3028 case CONTROL_DMARC_VERIFY:
3029 f.dmarc_disable_verify = TRUE;
3032 case CONTROL_DMARC_FORENSIC:
3033 f.dmarc_enable_forensic = TRUE;
3040 int fd, af, level, optname, value;
3041 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3042 a socket; we can accept that, we'll just debug-log failures anyway. */
3043 fd = fileno(smtp_in);
3044 af = ip_get_address_family(fd);
3048 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3052 if (dscp_lookup(p+1, af, &level, &optname, &value))
3054 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3056 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3057 p+1, strerror(errno));
3061 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3066 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3072 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3080 case CONTROL_CASEFUL_LOCAL_PART:
3081 deliver_localpart = addr->cc_local_part;
3084 case CONTROL_CASELOWER_LOCAL_PART:
3085 deliver_localpart = addr->lc_local_part;
3088 case CONTROL_ENFORCE_SYNC:
3089 smtp_enforce_sync = TRUE;
3092 case CONTROL_NO_ENFORCE_SYNC:
3093 smtp_enforce_sync = FALSE;
3096 #ifdef WITH_CONTENT_SCAN
3097 case CONTROL_NO_MBOX_UNSPOOL:
3098 f.no_mbox_unspool = TRUE;
3102 case CONTROL_NO_MULTILINE:
3103 f.no_multiline_responses = TRUE;
3106 case CONTROL_NO_PIPELINING:
3107 f.pipelining_enable = FALSE;
3110 case CONTROL_NO_DELAY_FLUSH:
3111 f.disable_delay_flush = TRUE;
3114 case CONTROL_NO_CALLOUT_FLUSH:
3115 f.disable_callout_flush = TRUE;
3118 case CONTROL_FAKEREJECT:
3119 cancel_cutthrough_connection(TRUE, US"fakereject");
3120 case CONTROL_FAKEDEFER:
3121 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3124 const uschar *pp = p + 1;
3126 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3131 /* Explicitly reset to default string */
3132 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).";
3136 case CONTROL_FREEZE:
3137 f.deliver_freeze = TRUE;
3138 deliver_frozen_at = time(NULL);
3139 freeze_tell = freeze_tell_config; /* Reset to configured value */
3140 if (Ustrncmp(p, "/no_tell", 8) == 0)
3147 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3150 cancel_cutthrough_connection(TRUE, US"item frozen");
3153 case CONTROL_QUEUE_ONLY:
3154 f.queue_only_policy = TRUE;
3155 cancel_cutthrough_connection(TRUE, US"queueing forced");
3158 case CONTROL_SUBMISSION:
3159 originator_name = US"";
3160 f.submission_mode = TRUE;
3163 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3166 f.active_local_sender_retain = TRUE;
3167 f.active_local_from_check = FALSE;
3169 else if (Ustrncmp(p, "/domain=", 8) == 0)
3171 const uschar *pp = p + 8;
3172 while (*pp && *pp != '/') pp++;
3173 submission_domain = string_copyn(p+8, pp-p-8);
3176 /* The name= option must be last, because it swallows the rest of
3178 else if (Ustrncmp(p, "/name=", 6) == 0)
3180 const uschar *pp = p + 6;
3182 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3183 big_buffer, big_buffer_size));
3190 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3197 uschar * debug_tag = NULL;
3198 uschar * debug_opts = NULL;
3203 const uschar * pp = p+1;
3204 if (Ustrncmp(pp, "tag=", 4) == 0)
3206 for (pp += 4; *pp && *pp != '/';) pp++;
3207 debug_tag = string_copyn(p+5, pp-p-5);
3209 else if (Ustrncmp(pp, "opts=", 5) == 0)
3211 for (pp += 5; *pp && *pp != '/';) pp++;
3212 debug_opts = string_copyn(p+6, pp-p-6);
3214 else if (Ustrncmp(pp, "kill", 4) == 0)
3216 for (pp += 4; *pp && *pp != '/';) pp++;
3220 while (*pp && *pp != '/') pp++;
3225 debug_logging_stop();
3227 debug_logging_activate(debug_tag, debug_opts);
3231 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3232 f.suppress_local_fixups = TRUE;
3235 case CONTROL_CUTTHROUGH_DELIVERY:
3237 uschar * ignored = NULL;
3238 #ifndef DISABLE_PRDR
3243 /* Too hard to think about for now. We might in future cutthrough
3244 the case where both sides handle prdr and this-node prdr acl
3246 ignored = US"PRDR active";
3249 if (f.deliver_freeze)
3250 ignored = US"frozen";
3251 else if (f.queue_only_policy)
3252 ignored = US"queue-only";
3253 else if (fake_response == FAIL)
3254 ignored = US"fakereject";
3257 if (rcpt_count == 1)
3259 cutthrough.delivery = TRUE; /* control accepted */
3262 const uschar * pp = p+1;
3263 if (Ustrncmp(pp, "defer=", 6) == 0)
3266 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3267 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3270 while (*pp && *pp != '/') pp++;
3275 ignored = US"nonfirst rcpt";
3278 DEBUG(D_acl) if (ignored)
3279 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3284 case CONTROL_UTF8_DOWNCONVERT:
3289 message_utf8_downconvert = 1;
3290 addr->prop.utf8_downcvt = TRUE;
3291 addr->prop.utf8_downcvt_maybe = FALSE;
3297 message_utf8_downconvert = 0;
3298 addr->prop.utf8_downcvt = FALSE;
3299 addr->prop.utf8_downcvt_maybe = FALSE;
3303 if (p[1] == '-' && p[2] == '1')
3305 message_utf8_downconvert = -1;
3306 addr->prop.utf8_downcvt = FALSE;
3307 addr->prop.utf8_downcvt_maybe = TRUE;
3311 *log_msgptr = US"bad option value for control=utf8_downconvert";
3315 message_utf8_downconvert = 1;
3316 addr->prop.utf8_downcvt = TRUE;
3317 addr->prop.utf8_downcvt_maybe = FALSE;
3327 #ifdef EXPERIMENTAL_DCC
3330 /* Separate the regular expression and any optional parameters. */
3331 const uschar * list = arg;
3332 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3333 /* Run the dcc backend. */
3334 rc = dcc_process(&ss);
3335 /* Modify return code based upon the existence of options. */
3336 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3337 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3338 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3343 #ifdef WITH_CONTENT_SCAN
3345 rc = mime_decode(&arg);
3351 int delay = readconf_readtime(arg, 0, FALSE);
3354 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3355 "modifier: \"%s\" is not a time value", arg);
3360 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3365 debug_printf_indent("delay skipped in -bh checking mode\n");
3368 /* NOTE 1: Remember that we may be
3369 dealing with stdin/stdout here, in addition to TCP/IP connections.
3370 Also, delays may be specified for non-SMTP input, where smtp_out and
3371 smtp_in will be NULL. Whatever is done must work in all cases.
3373 NOTE 2: The added feature of flushing the output before a delay must
3374 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3379 if (smtp_out && !f.disable_delay_flush)
3382 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3388 p.fd = fileno(smtp_out);
3389 p.events = POLLRDHUP;
3392 if (poll(&p, n, delay*1000) > 0)
3393 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3396 /* Lacking POLLRDHUP it appears to be impossible to detect that a
3397 TCP/IP connection has gone away without reading from it. This means
3398 that we cannot shorten the delay below if the client goes away,
3399 because we cannot discover that the client has closed its end of the
3400 connection. (The connection is actually in a half-closed state,
3401 waiting for the server to close its end.) It would be nice to be able
3402 to detect this state, so that the Exim process is not held up
3403 unnecessarily. However, it seems that we can't. The poll() function
3404 does not do the right thing, and in any case it is not always
3407 while (delay > 0) delay = sleep(delay);
3414 #ifndef DISABLE_DKIM
3415 case ACLC_DKIM_SIGNER:
3416 if (dkim_cur_signer)
3417 rc = match_isinlist(dkim_cur_signer,
3418 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3423 case ACLC_DKIM_STATUS:
3424 rc = match_isinlist(dkim_verify_status,
3425 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3429 #ifdef EXPERIMENTAL_DMARC
3430 case ACLC_DMARC_STATUS:
3431 if (!f.dmarc_has_been_checked)
3433 f.dmarc_has_been_checked = TRUE;
3434 /* used long way of dmarc_exim_expand_query() in case we need more
3435 * view into the process in the future. */
3436 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3437 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3442 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3446 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3447 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3450 /* The value in tls_cipher is the full cipher name, for example,
3451 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3452 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3453 what may in practice come out of the SSL library - which at the time of
3454 writing is poorly documented. */
3456 case ACLC_ENCRYPTED:
3457 if (tls_in.cipher == NULL) rc = FAIL; else
3459 uschar *endcipher = NULL;
3460 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3461 if (cipher == NULL) cipher = tls_in.cipher; else
3463 endcipher = Ustrchr(++cipher, ':');
3464 if (endcipher != NULL) *endcipher = 0;
3466 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3467 if (endcipher != NULL) *endcipher = ':';
3471 /* Use verify_check_this_host() instead of verify_check_host() so that
3472 we can pass over &host_data to catch any looked up data. Once it has been
3473 set, it retains its value so that it's still there if another ACL verb
3474 comes through here and uses the cache. However, we must put it into
3475 permanent store in case it is also expected to be used in a subsequent
3476 message in the same SMTP connection. */
3479 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3480 (sender_host_address == NULL)? US"" : sender_host_address,
3482 if (rc == DEFER) *log_msgptr = search_error_message;
3483 if (host_data) host_data = string_copy_malloc(host_data);
3486 case ACLC_LOCAL_PARTS:
3487 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3488 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3489 CUSS &deliver_localpart_data);
3492 case ACLC_LOG_REJECT_TARGET:
3496 const uschar *s = arg;
3498 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3500 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3501 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3502 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3505 logbits |= LOG_MAIN|LOG_REJECT;
3506 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3507 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3510 log_reject_target = logbits;
3517 const uschar *s = arg;
3523 if (Ustrncmp(s, "main", 4) == 0)
3524 { logbits |= LOG_MAIN; s += 4; }
3525 else if (Ustrncmp(s, "panic", 5) == 0)
3526 { logbits |= LOG_PANIC; s += 5; }
3527 else if (Ustrncmp(s, "reject", 6) == 0)
3528 { logbits |= LOG_REJECT; s += 6; }
3531 logbits = LOG_MAIN|LOG_PANIC;
3532 s = string_sprintf(":unknown log name in \"%s\" in "
3533 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3539 while (isspace(*s)) s++;
3541 if (logbits == 0) logbits = LOG_MAIN;
3542 log_write(0, logbits, "%s", string_printing(s));
3546 #ifdef WITH_CONTENT_SCAN
3547 case ACLC_MALWARE: /* Run the malware backend. */
3549 /* Separate the regular expression and any optional parameters. */
3550 const uschar * list = arg;
3551 uschar * ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3553 BOOL defer_ok = FALSE;
3556 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3557 if (strcmpic(opt, US"defer_ok") == 0)
3559 else if ( strncmpic(opt, US"tmo=", 4) == 0
3560 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3563 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3567 rc = malware(ss, timeout);
3568 if (rc == DEFER && defer_ok)
3569 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3573 case ACLC_MIME_REGEX:
3574 rc = mime_regex(&arg);
3579 if (Ustrchr(arg, '/'))
3581 *log_msgptr = string_sprintf(
3582 "Directory separator not permitted in queue name: '%s'", arg);
3585 queue_name = string_copy_malloc(arg);
3588 case ACLC_RATELIMIT:
3589 rc = acl_ratelimit(arg, where, log_msgptr);
3592 case ACLC_RECIPIENTS:
3593 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3594 CUSS &recipient_data);
3597 #ifdef WITH_CONTENT_SCAN
3603 case ACLC_REMOVE_HEADER:
3604 setup_remove_header(arg);
3607 case ACLC_SENDER_DOMAINS:
3610 sdomain = Ustrrchr(sender_address, '@');
3611 sdomain = sdomain ? sdomain + 1 : US"";
3612 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3613 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3618 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3619 sender_address_cache, -1, 0, CUSS &sender_data);
3622 /* Connection variables must persist forever */
3626 int old_pool = store_pool;
3627 if ( cb->u.varname[0] == 'c'
3628 #ifndef DISABLE_DKIM
3629 || cb->u.varname[0] == 'd'
3631 #ifndef DISABLE_EVENT
3632 || event_name /* An event is being delivered */
3635 store_pool = POOL_PERM;
3636 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3637 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3638 dkim_verify_status = string_copy(arg);
3639 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3640 dkim_verify_reason = string_copy(arg);
3643 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3644 store_pool = old_pool;
3648 #ifdef WITH_CONTENT_SCAN
3651 /* Separate the regular expression and any optional parameters. */
3652 const uschar * list = arg;
3653 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3655 rc = spam(CUSS &ss);
3656 /* Modify return code based upon the existence of options. */
3657 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3658 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3659 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3666 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3668 case ACLC_SPF_GUESS:
3669 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3674 rc = acl_udpsend(arg, log_msgptr);
3677 /* If the verb is WARN, discard any user message from verification, because
3678 such messages are SMTP responses, not header additions. The latter come
3679 only from explicit "message" modifiers. However, put the user message into
3680 $acl_verify_message so it can be used in subsequent conditions or modifiers
3681 (until something changes it). */
3684 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3686 acl_verify_message = *user_msgptr;
3687 if (verb == ACL_WARN) *user_msgptr = NULL;
3691 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3692 "condition %d", cb->type);
3696 /* If a condition was negated, invert OK/FAIL. */
3698 if (!conditions[cb->type].is_modifier && cb->u.negated)
3699 if (rc == OK) rc = FAIL;
3700 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3702 if (rc != OK) break; /* Conditions loop */
3706 /* If the result is the one for which "message" and/or "log_message" are used,
3707 handle the values of these modifiers. If there isn't a log message set, we make
3708 it the same as the user message.
3710 "message" is a user message that will be included in an SMTP response. Unless
3711 it is empty, it overrides any previously set user message.
3713 "log_message" is a non-user message, and it adds to any existing non-user
3714 message that is already set.
3716 Most verbs have but a single return for which the messages are relevant, but
3717 for "discard", it's useful to have the log message both when it succeeds and
3718 when it fails. For "accept", the message is used in the OK case if there is no
3719 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3722 if (*epp && rc == OK) user_message = NULL;
3724 if ((BIT(rc) & msgcond[verb]) != 0)
3727 uschar *old_user_msgptr = *user_msgptr;
3728 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3730 /* If the verb is "warn", messages generated by conditions (verification or
3731 nested ACLs) are always discarded. This also happens for acceptance verbs
3732 when they actually do accept. Only messages specified at this level are used.
3733 However, the value of an existing message is available in $acl_verify_message
3734 during expansions. */
3736 if (verb == ACL_WARN ||
3737 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3738 *log_msgptr = *user_msgptr = NULL;
3742 acl_verify_message = old_user_msgptr;
3743 expmessage = expand_string(user_message);
3746 if (!f.expand_string_forcedfail)
3747 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3748 user_message, expand_string_message);
3750 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3755 acl_verify_message = old_log_msgptr;
3756 expmessage = expand_string(log_message);
3759 if (!f.expand_string_forcedfail)
3760 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3761 log_message, expand_string_message);
3763 else if (expmessage[0] != 0)
3765 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3766 string_sprintf("%s: %s", expmessage, *log_msgptr);
3770 /* If no log message, default it to the user message */
3772 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3775 acl_verify_message = NULL;
3783 /*************************************************
3784 * Get line from a literal ACL *
3785 *************************************************/
3787 /* This function is passed to acl_read() in order to extract individual lines
3788 of a literal ACL, which we access via static pointers. We can destroy the
3789 contents because this is called only once (the compiled ACL is remembered).
3791 This code is intended to treat the data in the same way as lines in the main
3792 Exim configuration file. That is:
3794 . Leading spaces are ignored.
3796 . A \ at the end of a line is a continuation - trailing spaces after the \
3797 are permitted (this is because I don't believe in making invisible things
3798 significant). Leading spaces on the continued part of a line are ignored.
3800 . Physical lines starting (significantly) with # are totally ignored, and
3801 may appear within a sequence of backslash-continued lines.
3803 . Blank lines are ignored, but will end a sequence of continuations.
3806 Returns: a pointer to the next line
3810 static uschar *acl_text; /* Current pointer in the text */
3811 static uschar *acl_text_end; /* Points one past the terminating '0' */
3819 /* This loop handles leading blank lines and comments. */
3823 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3824 if (*acl_text == 0) return NULL; /* No more data */
3825 yield = acl_text; /* Potential data line */
3827 while (*acl_text && *acl_text != '\n') acl_text++;
3829 /* If we hit the end before a newline, we have the whole logical line. If
3830 it's a comment, there's no more data to be given. Otherwise, yield it. */
3832 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3834 /* After reaching a newline, end this loop if the physical line does not
3835 start with '#'. If it does, it's a comment, and the loop continues. */
3837 if (*yield != '#') break;
3840 /* This loop handles continuations. We know we have some real data, ending in
3841 newline. See if there is a continuation marker at the end (ignoring trailing
3842 white space). We know that *yield is not white space, so no need to test for
3843 cont > yield in the backwards scanning loop. */
3848 for (cont = acl_text - 1; isspace(*cont); cont--);
3850 /* If no continuation follows, we are done. Mark the end of the line and
3859 /* We have encountered a continuation. Skip over whitespace at the start of
3860 the next line, and indeed the whole of the next line or lines if they are
3865 while (*(++acl_text) == ' ' || *acl_text == '\t');
3866 if (*acl_text != '#') break;
3867 while (*(++acl_text) != 0 && *acl_text != '\n');
3870 /* We have the start of a continuation line. Move all the rest of the data
3871 to join onto the previous line, and then find its end. If the end is not a
3872 newline, we are done. Otherwise loop to look for another continuation. */
3874 memmove(cont, acl_text, acl_text_end - acl_text);
3875 acl_text_end -= acl_text - cont;
3877 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3878 if (*acl_text == 0) return yield;
3881 /* Control does not reach here */
3888 /*************************************************
3889 * Check access using an ACL *
3890 *************************************************/
3892 /* This function is called from address_check. It may recurse via
3893 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3894 passed as a string which is expanded. A forced failure implies no access check
3895 is required. If the result is a single word, it is taken as the name of an ACL
3896 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3897 text, complete with newlines, and parsed as such. In both cases, the ACL check
3898 is then run. This function uses an auxiliary function for acl_read() to call
3899 for reading individual lines of a literal ACL. This is acl_getline(), which
3900 appears immediately above.
3903 where where called from
3904 addr address item when called from RCPT; otherwise NULL
3905 s the input string; NULL is the same as an empty ACL => DENY
3906 user_msgptr where to put a user error (for SMTP response)
3907 log_msgptr where to put a logging message (not for SMTP response)
3909 Returns: OK access is granted
3910 DISCARD access is apparently granted...
3911 FAIL access is denied
3912 FAIL_DROP access is denied; drop the connection
3913 DEFER can't tell at the moment
3918 acl_check_internal(int where, address_item *addr, uschar *s,
3919 uschar **user_msgptr, uschar **log_msgptr)
3922 acl_block *acl = NULL;
3923 uschar *acl_name = US"inline ACL";
3926 /* Catch configuration loops */
3930 *log_msgptr = US"ACL nested too deep: possible loop";
3936 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3940 /* At top level, we expand the incoming string. At lower levels, it has already
3941 been expanded as part of condition processing. */
3945 if (!(ss = expand_string(s)))
3947 if (f.expand_string_forcedfail) return OK;
3948 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3949 expand_string_message);
3955 while (isspace(*ss)) ss++;
3957 /* If we can't find a named ACL, the default is to parse it as an inline one.
3958 (Unless it begins with a slash; non-existent files give rise to an error.) */
3962 /* Handle the case of a string that does not contain any spaces. Look for a
3963 named ACL among those read from the configuration, or a previously read file.
3964 It is possible that the pointer to the ACL is NULL if the configuration
3965 contains a name with no data. If not found, and the text begins with '/',
3966 read an ACL from a file, and save it so it can be re-used. */
3968 if (Ustrchr(ss, ' ') == NULL)
3970 tree_node * t = tree_search(acl_anchor, ss);
3973 if (!(acl = (acl_block *)(t->data.ptr)))
3975 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
3978 acl_name = string_sprintf("ACL \"%s\"", ss);
3979 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
3982 else if (*ss == '/')
3984 struct stat statbuf;
3985 if ((fd = Uopen(ss, O_RDONLY, 0)) < 0)
3987 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3992 if (fstat(fd, &statbuf) != 0)
3994 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3999 acl_text = store_get(statbuf.st_size + 1);
4000 acl_text_end = acl_text + statbuf.st_size + 1;
4002 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4004 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4005 ss, strerror(errno));
4008 acl_text[statbuf.st_size] = 0;
4011 acl_name = string_sprintf("ACL \"%s\"", ss);
4012 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4016 /* Parse an ACL that is still in text form. If it came from a file, remember it
4017 in the ACL tree, having read it into the POOL_PERM store pool so that it
4018 persists between multiple messages. */
4022 int old_pool = store_pool;
4023 if (fd >= 0) store_pool = POOL_PERM;
4024 acl = acl_read(acl_getline, log_msgptr);
4025 store_pool = old_pool;
4026 if (!acl && *log_msgptr) return ERROR;
4029 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
4030 Ustrcpy(t->name, ss);
4032 (void)tree_insertnode(&acl_anchor, t);
4036 /* Now we have an ACL to use. It's possible it may be NULL. */
4041 int basic_errno = 0;
4042 BOOL endpass_seen = FALSE;
4043 BOOL acl_quit_check = acl_level == 0
4044 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4046 *log_msgptr = *user_msgptr = NULL;
4047 f.acl_temp_details = FALSE;
4049 HDEBUG(D_acl) debug_printf_indent("processing \"%s\" (%s %d)\n",
4050 verbs[acl->verb], acl->srcfile, acl->srcline);
4052 /* Clear out any search error message from a previous check before testing
4055 search_error_message = NULL;
4056 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4057 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4059 /* Handle special returns: DEFER causes a return except on a WARN verb;
4060 ERROR always causes a return. */
4065 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n",
4066 verbs[acl->verb], acl_name);
4067 if (basic_errno != ERRNO_CALLOUTDEFER)
4069 if (search_error_message != NULL && *search_error_message != 0)
4070 *log_msgptr = search_error_message;
4071 if (smtp_return_error_details) f.acl_temp_details = TRUE;
4074 f.acl_temp_details = TRUE;
4075 if (acl->verb != ACL_WARN) return DEFER;
4078 default: /* Paranoia */
4080 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n",
4081 verbs[acl->verb], acl_name);
4085 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4086 verbs[acl->verb], acl_name);
4090 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n",
4091 verbs[acl->verb], acl_name);
4094 /* DISCARD and DROP can happen only from a nested ACL condition, and
4095 DISCARD can happen only for an "accept" or "discard" verb. */
4098 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4099 verbs[acl->verb], acl_name);
4103 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4104 verbs[acl->verb], acl_name);
4108 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4109 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4110 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4115 if (cond == OK || cond == DISCARD)
4117 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4122 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4130 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4131 if (acl_quit_check) goto badquit;
4132 f.acl_temp_details = TRUE;
4140 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4141 if (acl_quit_check) goto badquit;
4147 if (cond == OK || cond == DISCARD)
4149 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4150 if (acl_quit_check) goto badquit;
4156 debug_printf_indent("discard: endpass encountered - denying access\n");
4164 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4165 if (acl_quit_check) goto badquit;
4173 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4174 if (acl_quit_check) goto badquit;
4181 acl_warn(where, *user_msgptr, *log_msgptr);
4182 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4183 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4184 "condition test deferred%s%s", host_and_ident(TRUE),
4185 (*log_msgptr == NULL)? US"" : US": ",
4186 (*log_msgptr == NULL)? US"" : *log_msgptr);
4187 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4191 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4196 /* Pass to the next ACL item */
4201 /* We have reached the end of the ACL. This is an implicit DENY. */
4203 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4207 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4208 "('%s' verb used incorrectly)", verbs[acl->verb]);
4215 /* Same args as acl_check_internal() above, but the string s is
4216 the name of an ACL followed optionally by up to 9 space-separated arguments.
4217 The name and args are separately expanded. Args go into $acl_arg globals. */
4219 acl_check_wargs(int where, address_item *addr, const uschar *s,
4220 uschar **user_msgptr, uschar **log_msgptr)
4223 uschar * tmp_arg[9]; /* must match acl_arg[] */
4224 uschar * sav_arg[9]; /* must match acl_arg[] */
4230 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4233 for (i = 0; i < 9; i++)
4235 while (*s && isspace(*s)) s++;
4237 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4244 sav_narg = acl_narg;
4246 for (i = 0; i < acl_narg; i++)
4248 sav_arg[i] = acl_arg[i];
4249 acl_arg[i] = tmp_arg[i];
4253 sav_arg[i] = acl_arg[i];
4254 acl_arg[i++] = NULL;
4258 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4261 acl_narg = sav_narg;
4262 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4266 if (f.expand_string_forcedfail) return ERROR;
4267 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4268 tmp, expand_string_message);
4269 return f.search_find_defer ? DEFER : ERROR;
4274 /*************************************************
4275 * Check access using an ACL *
4276 *************************************************/
4278 /* Alternate interface for ACL, used by expansions */
4280 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4283 address_item *addr = NULL;
4286 *user_msgptr = *log_msgptr = NULL;
4287 sender_verified_failed = NULL;
4288 ratelimiters_cmd = NULL;
4289 log_reject_target = LOG_MAIN|LOG_REJECT;
4291 if (where == ACL_WHERE_RCPT)
4293 adb = address_defaults;
4295 addr->address = expand_string(US"$local_part@$domain");
4296 addr->domain = deliver_domain;
4297 addr->local_part = deliver_localpart;
4298 addr->cc_local_part = deliver_localpart;
4299 addr->lc_local_part = deliver_localpart;
4303 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4310 /* This is the external interface for ACL checks. It sets up an address and the
4311 expansions for $domain and $local_part when called after RCPT, then calls
4312 acl_check_internal() to do the actual work.
4315 where ACL_WHERE_xxxx indicating where called from
4316 recipient RCPT address for RCPT check, else NULL
4317 s the input string; NULL is the same as an empty ACL => DENY
4318 user_msgptr where to put a user error (for SMTP response)
4319 log_msgptr where to put a logging message (not for SMTP response)
4321 Returns: OK access is granted by an ACCEPT verb
4322 DISCARD access is granted by a DISCARD verb
4323 FAIL access is denied
4324 FAIL_DROP access is denied; drop the connection
4325 DEFER can't tell at the moment
4328 int acl_where = ACL_WHERE_UNKNOWN;
4331 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4332 uschar **log_msgptr)
4336 address_item *addr = NULL;
4338 *user_msgptr = *log_msgptr = NULL;
4339 sender_verified_failed = NULL;
4340 ratelimiters_cmd = NULL;
4341 log_reject_target = LOG_MAIN|LOG_REJECT;
4343 #ifndef DISABLE_PRDR
4344 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4346 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4349 adb = address_defaults;
4351 addr->address = recipient;
4352 if (deliver_split_address(addr) == DEFER)
4354 *log_msgptr = US"defer in percent_hack_domains check";
4358 if ((addr->prop.utf8_msg = message_smtputf8))
4360 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4361 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4364 deliver_domain = addr->domain;
4365 deliver_localpart = addr->local_part;
4370 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4372 acl_where = ACL_WHERE_UNKNOWN;
4374 /* Cutthrough - if requested,
4375 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4376 and rcpt acl returned accept,
4377 and first recipient (cancel on any subsequents)
4378 open one now and run it up to RCPT acceptance.
4379 A failed verify should cancel cutthrough request,
4380 and will pass the fail to the originator.
4381 Initial implementation: dual-write to spool.
4382 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4384 Cease cutthrough copy on rxd final dot; do not send one.
4386 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4388 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4389 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4390 If temp-reject, close the conn (and keep the spooled copy).
4391 If conn-failure, no action (and keep the spooled copy).
4395 case ACL_WHERE_RCPT:
4396 #ifndef DISABLE_PRDR
4397 case ACL_WHERE_PRDR:
4400 if (f.host_checking_callout) /* -bhc mode */
4401 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4404 && cutthrough.delivery
4405 && rcpt_count > cutthrough.nrcpt
4408 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4409 if (cutthrough.defer_pass)
4411 uschar * s = addr->message;
4412 /* Horrid kludge to recover target's SMTP message */
4414 do --s; while (!isdigit(*s));
4415 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4416 f.acl_temp_details = TRUE;
4420 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4424 else HDEBUG(D_acl) if (cutthrough.delivery)
4425 if (rcpt_count <= cutthrough.nrcpt)
4426 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4428 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4431 case ACL_WHERE_PREDATA:
4433 cutthrough_predata();
4435 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4438 case ACL_WHERE_QUIT:
4439 case ACL_WHERE_NOTQUIT:
4440 /* Drop cutthrough conns, and drop heldopen verify conns if
4441 the previous was not DATA */
4443 uschar prev = smtp_connection_had[smtp_ch_index-2];
4444 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4446 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4454 deliver_domain = deliver_localpart = deliver_address_data =
4455 deliver_domain_data = sender_address_data = NULL;
4457 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4458 ACL, which is really in the middle of an SMTP command. */
4462 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4464 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4465 "ACL", acl_wherenames[where]);
4471 /* A DROP response is not permitted from MAILAUTH */
4473 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4475 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4476 "ACL", acl_wherenames[where]);
4480 /* Before giving a response, take a look at the length of any user message, and
4481 split it up into multiple lines if possible. */
4483 *user_msgptr = string_split_message(*user_msgptr);
4484 if (fake_response != OK)
4485 fake_response_text = string_split_message(fake_response_text);
4491 /*************************************************
4492 * Create ACL variable *
4493 *************************************************/
4495 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4496 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4499 name pointer to the variable's name, starting with c or m
4501 Returns the pointer to variable's tree node
4505 acl_var_create(uschar * name)
4507 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4508 if (!(node = tree_search(*root, name)))
4510 node = store_get(sizeof(tree_node) + Ustrlen(name));
4511 Ustrcpy(node->name, name);
4512 (void)tree_insertnode(root, node);
4514 node->data.ptr = NULL;
4520 /*************************************************
4521 * Write an ACL variable in spool format *
4522 *************************************************/
4524 /* This function is used as a callback for tree_walk when writing variables to
4525 the spool file. To retain spool file compatibility, what is written is -aclc or
4526 -aclm followed by the rest of the name and the data length, space separated,
4527 then the value itself, starting on a new line, and terminated by an additional
4528 newline. When we had only numbered ACL variables, the first line might look
4529 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4533 name of the variable
4534 value of the variable
4535 ctx FILE pointer (as a void pointer)
4541 acl_var_write(uschar *name, uschar *value, void *ctx)
4543 FILE *f = (FILE *)ctx;
4544 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);