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)
513 [CONTROL_SUBMISSION] =
514 { US"submission", TRUE,
516 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA)
518 [CONTROL_SUPPRESS_LOCAL_FIXUPS] =
519 { US"suppress_local_fixups", FALSE,
521 ~(ACL_BIT_MAIL | ACL_BIT_RCPT | ACL_BIT_PREDATA |
522 ACL_BIT_NOTSMTP_START)
525 [CONTROL_UTF8_DOWNCONVERT] =
526 { US"utf8_downconvert", TRUE, (unsigned) ~(ACL_BIT_RCPT | ACL_BIT_VRFY)
531 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
532 caches its result in a tree to avoid repeated DNS queries. The result is an
533 integer code which is used as an index into the following tables of
534 explanatory strings and verification return codes. */
536 static tree_node *csa_cache = NULL;
538 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
539 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
541 /* The acl_verify_csa() return code is translated into an acl_verify() return
542 code using the following table. It is OK unless the client is definitely not
543 authorized. This is because CSA is supposed to be optional for sending sites,
544 so recipients should not be too strict about checking it - especially because
545 DNS problems are quite likely to occur. It's possible to use $csa_status in
546 further ACL conditions to distinguish ok, unknown, and defer if required, but
547 the aim is to make the usual configuration simple. */
549 static int csa_return_code[] = {
552 [CSA_DEFER_SRV] = OK,
553 [CSA_DEFER_ADDR] = OK,
554 [CSA_FAIL_EXPLICIT] = FAIL,
555 [CSA_FAIL_DOMAIN] = FAIL,
556 [CSA_FAIL_NOADDR] = FAIL,
557 [CSA_FAIL_MISMATCH] = FAIL
560 static uschar *csa_status_string[] = {
561 [CSA_UNKNOWN] = US"unknown",
563 [CSA_DEFER_SRV] = US"defer",
564 [CSA_DEFER_ADDR] = US"defer",
565 [CSA_FAIL_EXPLICIT] = US"fail",
566 [CSA_FAIL_DOMAIN] = US"fail",
567 [CSA_FAIL_NOADDR] = US"fail",
568 [CSA_FAIL_MISMATCH] = US"fail"
571 static uschar *csa_reason_string[] = {
572 [CSA_UNKNOWN] = US"unknown",
574 [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)",
575 [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)",
576 [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)",
577 [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)",
578 [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)",
579 [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)"
582 /* Options for the ratelimit condition. Note that there are two variants of
583 the per_rcpt option, depending on the ACL that is used to measure the rate.
584 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
585 so the two variants must have the same internal representation as well as
586 the same configuration string. */
589 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
590 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
593 #define RATE_SET(var,new) \
594 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
596 static uschar *ratelimit_option_string[] = {
597 [RATE_PER_WHAT] = US"?",
598 [RATE_PER_CLASH] = US"!",
599 [RATE_PER_ADDR] = US"per_addr",
600 [RATE_PER_BYTE] = US"per_byte",
601 [RATE_PER_CMD] = US"per_cmd",
602 [RATE_PER_CONN] = US"per_conn",
603 [RATE_PER_MAIL] = US"per_mail",
604 [RATE_PER_RCPT] = US"per_rcpt",
605 [RATE_PER_ALLRCPTS] = US"per_rcpt"
608 /* Enable recursion between acl_check_internal() and acl_check_condition() */
610 static int acl_check_wargs(int, address_item *, const uschar *, uschar **,
614 /*************************************************
615 * Find control in list *
616 *************************************************/
618 /* The lists are always in order, so binary chop can be used.
621 name the control name to search for
622 ol the first entry in the control list
623 last one more than the offset of the last entry in the control list
625 Returns: index of a control entry, or -1 if not found
629 find_control(const uschar * name, control_def * ol, int last)
634 int middle = (first + last)/2;
635 uschar * s = ol[middle].name;
636 int c = Ustrncmp(name, s, Ustrlen(s));
637 if (c == 0) return middle;
638 else if (c > 0) first = middle + 1;
646 /*************************************************
647 * Pick out condition from list *
648 *************************************************/
650 /* Use a binary chop method
654 list list of conditions
657 Returns: offset in list, or -1 if not found
661 acl_checkcondition(uschar * name, condition_def * list, int 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)
697 int mid = (start + end)/2;
698 int c = Ustrcmp(name, list[mid]);
699 if (c == 0) return mid;
700 if (c < 0) end = mid; else start = mid + 1;
707 /*************************************************
708 * Read and parse one ACL *
709 *************************************************/
711 /* This function is called both from readconf in order to parse the ACLs in the
712 configuration file, and also when an ACL is encountered dynamically (e.g. as
713 the result of an expansion). It is given a function to call in order to
714 retrieve the lines of the ACL. This function handles skipping comments and
715 blank lines (where relevant).
718 func function to get next line of ACL
719 error where to put an error message
721 Returns: pointer to ACL, or NULL
722 NULL can be legal (empty ACL); in this case error will be NULL
726 acl_read(uschar *(*func)(void), uschar **error)
728 acl_block *yield = NULL;
729 acl_block **lastp = &yield;
730 acl_block *this = NULL;
731 acl_condition_block *cond;
732 acl_condition_block **condp = NULL;
737 while ((s = (*func)()) != NULL)
740 BOOL negated = FALSE;
741 uschar *saveline = s;
744 /* Conditions (but not verbs) are allowed to be negated by an initial
747 while (isspace(*s)) s++;
754 /* Read the name of a verb or a condition, or the start of a new ACL, which
755 can be started by a name, or by a macro definition. */
757 s = readconf_readname(name, sizeof(name), s);
758 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
760 /* If a verb is unrecognized, it may be another condition or modifier that
761 continues the previous verb. */
763 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
767 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
779 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
782 this = store_get(sizeof(acl_block));
784 lastp = &(this->next);
787 this->condition = NULL;
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 *************************************************/
1045 header_line * h = acl_added_headers;
1049 if (!h) return NULL;
1054 while ((cp = Ustrchr(s, '\n')) != NULL)
1056 if (cp[1] == '\0') break;
1058 /* contains embedded newline; needs doubling */
1059 g = string_catn(g, s, cp-s+1);
1060 g = string_catn(g, US"\n", 1);
1063 /* last bit of header */
1065 /*XXX could we use add_listele? */
1066 g = string_catn(g, s, cp-s+1); /* newline-sep list */
1068 while((h = h->next));
1070 g->s[g->ptr - 1] = '\0'; /* overwrite last newline */
1075 /*************************************************
1076 * Set up removed header line(s) *
1077 *************************************************/
1079 /* This function is called by the remove_header modifier. The argument is
1080 treated as a sequence of header names which are added to a colon separated
1081 list, provided there isn't an identical one already there.
1083 Argument: string of header names
1088 setup_remove_header(const uschar *hnames)
1091 acl_removed_headers = acl_removed_headers
1092 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1093 : string_copy(hnames);
1098 /*************************************************
1100 *************************************************/
1102 /* This function is called when a WARN verb's conditions are true. It adds to
1103 the message's headers, and/or writes information to the log. In each case, this
1104 only happens once (per message for headers, per connection for log).
1106 ** NOTE: The header adding action using the "message" setting is historic, and
1107 its use is now deprecated. The new add_header modifier should be used instead.
1110 where ACL_WHERE_xxxx indicating which ACL this is
1111 user_message message for adding to headers
1112 log_message message for logging, if different
1118 acl_warn(int where, uschar *user_message, uschar *log_message)
1120 if (log_message != NULL && log_message != user_message)
1123 string_item *logged;
1125 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1126 string_printing(log_message));
1128 /* If a sender verification has failed, and the log message is "sender verify
1129 failed", add the failure message. */
1131 if (sender_verified_failed != NULL &&
1132 sender_verified_failed->message != NULL &&
1133 strcmpic(log_message, US"sender verify failed") == 0)
1134 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1136 /* Search previously logged warnings. They are kept in malloc
1137 store so they can be freed at the start of a new message. */
1139 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1140 if (Ustrcmp(logged->text, text) == 0) break;
1144 int length = Ustrlen(text) + 1;
1145 log_write(0, LOG_MAIN, "%s", text);
1146 logged = store_malloc(sizeof(string_item) + length);
1147 logged->text = US logged + sizeof(string_item);
1148 memcpy(logged->text, text, length);
1149 logged->next = acl_warn_logged;
1150 acl_warn_logged = logged;
1154 /* If there's no user message, we are done. */
1156 if (user_message == NULL) return;
1158 /* If this isn't a message ACL, we can't do anything with a user message.
1161 if (where > ACL_WHERE_NOTSMTP)
1163 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1164 "found in a non-message (%s) ACL: cannot specify header lines here: "
1165 "message ignored", acl_wherenames[where]);
1169 /* The code for setting up header lines is now abstracted into a separate
1170 function so that it can be used for the add_header modifier as well. */
1172 setup_header(user_message);
1177 /*************************************************
1178 * Verify and check reverse DNS *
1179 *************************************************/
1181 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1182 address if this has not yet been done. The host_name_lookup() function checks
1183 that one of these names resolves to an address list that contains the client IP
1184 address, so we don't actually have to do the check here.
1187 user_msgptr pointer for user message
1188 log_msgptr pointer for log message
1190 Returns: OK verification condition succeeded
1191 FAIL verification failed
1192 DEFER there was a problem verifying
1196 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1200 user_msgptr = user_msgptr; /* stop compiler warning */
1202 /* Previous success */
1204 if (sender_host_name != NULL) return OK;
1206 /* Previous failure */
1208 if (host_lookup_failed)
1210 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1214 /* Need to do a lookup */
1217 debug_printf_indent("looking up host name to force name/address consistency check\n");
1219 if ((rc = host_name_lookup()) != OK)
1221 *log_msgptr = (rc == DEFER)?
1222 US"host lookup deferred for reverse lookup check"
1224 string_sprintf("host lookup failed for reverse lookup check%s",
1226 return rc; /* DEFER or FAIL */
1229 host_build_sender_fullhost();
1235 /*************************************************
1236 * Check client IP address matches CSA target *
1237 *************************************************/
1239 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1240 response for address records belonging to the CSA target hostname. The section
1241 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1242 If one of the addresses matches the client's IP address, then the client is
1243 authorized by CSA. If there are target IP addresses but none of them match
1244 then the client is using an unauthorized IP address. If there are no target IP
1245 addresses then the client cannot be using an authorized IP address. (This is
1246 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1249 dnsa the DNS answer block
1250 dnss a DNS scan block for us to use
1251 reset option specifying what portion to scan, as described above
1252 target the target hostname to use for matching RR names
1254 Returns: CSA_OK successfully authorized
1255 CSA_FAIL_MISMATCH addresses found but none matched
1256 CSA_FAIL_NOADDR no target addresses found
1260 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1266 BOOL target_found = FALSE;
1268 for (rr = dns_next_rr(dnsa, dnss, reset);
1270 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1272 /* Check this is an address RR for the target hostname. */
1276 && rr->type != T_AAAA
1280 if (strcmpic(target, rr->name) != 0) continue;
1282 target_found = TRUE;
1284 /* Turn the target address RR into a list of textual IP addresses and scan
1285 the list. There may be more than one if it is an A6 RR. */
1287 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1289 /* If the client IP address matches the target IP address, it's good! */
1291 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1293 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1297 /* If we found some target addresses but none of them matched, the client is
1298 using an unauthorized IP address, otherwise the target has no authorized IP
1301 if (target_found) return CSA_FAIL_MISMATCH;
1302 else return CSA_FAIL_NOADDR;
1307 /*************************************************
1308 * Verify Client SMTP Authorization *
1309 *************************************************/
1311 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1312 to find the CSA SRV record corresponding to the domain argument, or
1313 $sender_helo_name if no argument is provided. It then checks that the
1314 client is authorized, and that its IP address corresponds to the SRV
1315 target's address by calling acl_verify_csa_address() above. The address
1316 should have been returned in the DNS response's ADDITIONAL section, but if
1317 not we perform another DNS lookup to get it.
1320 domain pointer to optional parameter following verify = csa
1322 Returns: CSA_UNKNOWN no valid CSA record found
1323 CSA_OK successfully authorized
1324 CSA_FAIL_* client is definitely not authorized
1325 CSA_DEFER_* there was a DNS problem
1329 acl_verify_csa(const uschar *domain)
1332 const uschar *found;
1333 int priority, weight, port;
1340 /* Work out the domain we are using for the CSA lookup. The default is the
1341 client's HELO domain. If the client has not said HELO, use its IP address
1342 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1344 while (isspace(*domain) && *domain != '\0') ++domain;
1345 if (*domain == '\0') domain = sender_helo_name;
1346 if (domain == NULL) domain = sender_host_address;
1347 if (sender_host_address == NULL) return CSA_UNKNOWN;
1349 /* If we have an address literal, strip off the framing ready for turning it
1350 into a domain. The framing consists of matched square brackets possibly
1351 containing a keyword and a colon before the actual IP address. */
1353 if (domain[0] == '[')
1355 const uschar *start = Ustrchr(domain, ':');
1356 if (start == NULL) start = domain;
1357 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1360 /* Turn domains that look like bare IP addresses into domains in the reverse
1361 DNS. This code also deals with address literals and $sender_host_address. It's
1362 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1363 address literals, but it's probably the most friendly thing to do. This is an
1364 extension to CSA, so we allow it to be turned off for proper conformance. */
1366 if (string_is_ip_address(domain, NULL) != 0)
1368 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1369 dns_build_reverse(domain, target);
1373 /* Find out if we've already done the CSA check for this domain. If we have,
1374 return the same result again. Otherwise build a new cached result structure
1375 for this domain. The name is filled in now, and the value is filled in when
1376 we return from this function. */
1378 t = tree_search(csa_cache, domain);
1379 if (t != NULL) return t->data.val;
1381 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1382 Ustrcpy(t->name, domain);
1383 (void)tree_insertnode(&csa_cache, t);
1385 /* Now we are ready to do the actual DNS lookup(s). */
1388 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1390 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1393 return t->data.val = CSA_DEFER_SRV;
1395 /* If we found nothing, the client's authorization is unknown. */
1399 return t->data.val = CSA_UNKNOWN;
1401 /* We got something! Go on to look at the reply in more detail. */
1407 /* Scan the reply for well-formed CSA SRV records. */
1409 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1411 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1413 const uschar * p = rr->data;
1415 /* Extract the numerical SRV fields (p is incremented) */
1417 GETSHORT(priority, p);
1418 GETSHORT(weight, p);
1422 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1424 /* Check the CSA version number */
1426 if (priority != 1) continue;
1428 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1429 found by dns_special_lookup() is a parent of the one we asked for), we check
1430 the subdomain assertions in the port field. At the moment there's only one
1431 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1432 SRV records of their own. */
1434 if (Ustrcmp(found, domain) != 0)
1435 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1437 /* This CSA SRV record refers directly to our domain, so we check the value
1438 in the weight field to work out the domain's authorization. 0 and 1 are
1439 unauthorized; 3 means the client is authorized but we can't check the IP
1440 address in order to authenticate it, so we treat it as unknown; values
1441 greater than 3 are undefined. */
1443 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1445 if (weight > 2) continue;
1447 /* Weight == 2, which means the domain is authorized. We must check that the
1448 client's IP address is listed as one of the SRV target addresses. Save the
1449 target hostname then break to scan the additional data for its addresses. */
1451 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1452 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1454 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1459 /* If we didn't break the loop then no appropriate records were found. */
1461 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1463 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1464 A target of "." indicates there are no valid addresses, so the client cannot
1465 be authorized. (This is an odd configuration because weight=2 target=. is
1466 equivalent to weight=1, but we check for it in order to keep load off the
1467 root name servers.) Note that dn_expand() turns "." into "". */
1469 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1471 /* Scan the additional section of the CSA SRV reply for addresses belonging
1472 to the target. If the name server didn't return any additional data (e.g.
1473 because it does not fully support SRV records), we need to do another lookup
1474 to obtain the target addresses; otherwise we have a definitive result. */
1476 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1477 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1479 /* The DNS lookup type corresponds to the IP version used by the client. */
1482 if (Ustrchr(sender_host_address, ':') != NULL)
1485 #endif /* HAVE_IPV6 */
1489 lookup_dnssec_authenticated = NULL;
1490 switch (dns_lookup(&dnsa, target, type, NULL))
1492 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1495 return t->data.val = CSA_DEFER_ADDR;
1497 /* If the query succeeded, scan the addresses and return the result. */
1500 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1501 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1502 /* else fall through */
1504 /* If the target has no IP addresses, the client cannot have an authorized
1505 IP address. However, if the target site uses A6 records (not AAAA records)
1506 we have to do yet another lookup in order to check them. */
1510 return t->data.val = CSA_FAIL_NOADDR;
1516 /*************************************************
1517 * Handle verification (address & other) *
1518 *************************************************/
1520 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1521 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1522 VERIFY_HDR_NAMES_ASCII, VERIFY_ARC
1527 unsigned where_allowed; /* bitmap */
1528 BOOL no_options; /* Never has /option(s) following */
1529 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1531 static verify_type_t verify_type_list[] = {
1532 /* name value where no-opt opt-sep */
1533 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, FALSE, 0 },
1534 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1535 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1536 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1537 { US"header_syntax", VERIFY_HDR_SYNTAX, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1538 { US"not_blind", VERIFY_NOT_BLIND, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1539 { US"header_sender", VERIFY_HDR_SNDR, ACL_BIT_DATA | ACL_BIT_NOTSMTP, FALSE, 0 },
1540 { US"sender", VERIFY_SNDR, ACL_BIT_MAIL | ACL_BIT_RCPT
1541 |ACL_BIT_PREDATA | ACL_BIT_DATA | ACL_BIT_NOTSMTP,
1543 { US"recipient", VERIFY_RCPT, ACL_BIT_RCPT, FALSE, 0 },
1544 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, ACL_BIT_DATA | ACL_BIT_NOTSMTP, TRUE, 0 },
1545 #ifdef EXPERIMENTAL_ARC
1546 { US"arc", VERIFY_ARC, ACL_BIT_DATA, FALSE , 0 },
1551 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1552 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1553 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1554 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1560 BOOL has_option; /* Has =option(s) following */
1561 BOOL timeval; /* Has a time value */
1563 static callout_opt_t callout_opt_list[] = {
1564 /* name value flag has-opt has-time */
1565 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1566 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1567 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1568 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1569 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1570 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1571 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1572 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1573 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1574 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1575 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1576 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1577 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1582 /* This function implements the "verify" condition. It is called when
1583 encountered in any ACL, because some tests are almost always permitted. Some
1584 just don't make sense, and always fail (for example, an attempt to test a host
1585 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1588 where where called from
1589 addr the recipient address that the ACL is handling, or NULL
1590 arg the argument of "verify"
1591 user_msgptr pointer for user message
1592 log_msgptr pointer for log message
1593 basic_errno where to put verify errno
1595 Returns: OK verification condition succeeded
1596 FAIL verification failed
1597 DEFER there was a problem verifying
1602 acl_verify(int where, address_item *addr, const uschar *arg,
1603 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1607 int callout_overall = -1;
1608 int callout_connect = -1;
1609 int verify_options = 0;
1611 BOOL verify_header_sender = FALSE;
1612 BOOL defer_ok = FALSE;
1613 BOOL callout_defer_ok = FALSE;
1614 BOOL no_details = FALSE;
1615 BOOL success_on_redirect = FALSE;
1616 address_item *sender_vaddr = NULL;
1617 uschar *verify_sender_address = NULL;
1618 uschar *pm_mailfrom = NULL;
1619 uschar *se_mailfrom = NULL;
1621 /* Some of the verify items have slash-separated options; some do not. Diagnose
1622 an error if options are given for items that don't expect them.
1625 uschar *slash = Ustrchr(arg, '/');
1626 const uschar *list = arg;
1627 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1630 if (!ss) goto BAD_VERIFY;
1632 /* Handle name/address consistency verification in a separate function. */
1634 for (vp= verify_type_list;
1635 CS vp < CS verify_type_list + sizeof(verify_type_list);
1638 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1639 : strcmpic (ss, vp->name) == 0)
1641 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1644 if (vp->no_options && slash)
1646 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1647 "(this verify item has no options)", arg);
1650 if (!(vp->where_allowed & BIT(where)))
1652 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s",
1653 vp->name, acl_wherenames[where]);
1658 case VERIFY_REV_HOST_LKUP:
1659 if (!sender_host_address) return OK;
1660 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1661 while ((ss = string_nextinlist(&list, &sep, NULL, 0)))
1662 if (strcmpic(ss, US"defer_ok") == 0)
1667 /* TLS certificate verification is done at STARTTLS time; here we just
1668 test whether it was successful or not. (This is for optional verification; for
1669 mandatory verification, the connection doesn't last this long.) */
1671 if (tls_in.certificate_verified) return OK;
1672 *user_msgptr = US"no verified certificate";
1676 /* We can test the result of optional HELO verification that might have
1677 occurred earlier. If not, we can attempt the verification now. */
1679 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1680 return helo_verified ? OK : FAIL;
1683 /* Do Client SMTP Authorization checks in a separate function, and turn the
1684 result code into user-friendly strings. */
1686 rc = acl_verify_csa(list);
1687 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1688 csa_reason_string[rc]);
1689 csa_status = csa_status_string[rc];
1690 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1691 return csa_return_code[rc];
1693 #ifdef EXPERIMENTAL_ARC
1695 { /* Do Authenticated Received Chain checks in a separate function. */
1696 const uschar * condlist = CUS string_nextinlist(&list, &sep, NULL, 0);
1700 if (!(arc_state = acl_verify_arc())) return DEFER;
1701 DEBUG(D_acl) debug_printf_indent("ARC verify result %s\n", arc_state);
1703 if (!condlist) condlist = US"none:pass";
1704 while ((cond = string_nextinlist(&condlist, &csep, NULL, 0)))
1705 if (Ustrcmp(arc_state, cond) == 0) return OK;
1710 case VERIFY_HDR_SYNTAX:
1711 /* Check that all relevant header lines have the correct 5322-syntax. If there is
1712 a syntax error, we return details of the error to the sender if configured to
1713 send out full details. (But a "message" setting on the ACL can override, as
1716 rc = verify_check_headers(log_msgptr);
1717 if (rc != OK && *log_msgptr)
1718 if (smtp_return_error_details)
1719 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1721 acl_verify_message = *log_msgptr;
1724 case VERIFY_HDR_NAMES_ASCII:
1725 /* Check that all header names are true 7 bit strings
1726 See RFC 5322, 2.2. and RFC 6532, 3. */
1728 rc = verify_check_header_names_ascii(log_msgptr);
1729 if (rc != OK && smtp_return_error_details && *log_msgptr)
1730 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1733 case VERIFY_NOT_BLIND:
1734 /* Check that no recipient of this message is "blind", that is, every envelope
1735 recipient must be mentioned in either To: or Cc:. */
1737 if ((rc = verify_check_notblind()) != OK)
1739 *log_msgptr = string_sprintf("bcc recipient detected");
1740 if (smtp_return_error_details)
1741 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1745 /* The remaining verification tests check recipient and sender addresses,
1746 either from the envelope or from the header. There are a number of
1747 slash-separated options that are common to all of them. */
1749 case VERIFY_HDR_SNDR:
1750 verify_header_sender = TRUE;
1754 /* In the case of a sender, this can optionally be followed by an address to use
1755 in place of the actual sender (rare special-case requirement). */
1759 verify_sender_address = sender_address;
1762 while (isspace(*s)) s++;
1763 if (*s++ != '=') goto BAD_VERIFY;
1764 while (isspace(*s)) s++;
1765 verify_sender_address = string_copy(s);
1776 /* Remaining items are optional; they apply to sender and recipient
1777 verification, including "header sender" verification. */
1779 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1782 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1783 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1784 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1786 /* These two old options are left for backwards compatibility */
1788 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1790 callout_defer_ok = TRUE;
1791 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1794 else if (strcmpic(ss, US"check_postmaster") == 0)
1797 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1800 /* The callout option has a number of sub-options, comma separated */
1802 else if (strncmpic(ss, US"callout", 7) == 0)
1804 callout = CALLOUT_TIMEOUT_DEFAULT;
1808 while (isspace(*ss)) ss++;
1811 const uschar * sublist = ss;
1815 while (isspace(*sublist)) sublist++;
1817 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1820 double period = 1.0F;
1822 for (op= callout_opt_list; op->name; op++)
1823 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1826 verify_options |= op->flag;
1829 opt += Ustrlen(op->name);
1830 while (isspace(*opt)) opt++;
1833 *log_msgptr = string_sprintf("'=' expected after "
1834 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1837 while (isspace(*opt)) opt++;
1839 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1841 *log_msgptr = string_sprintf("bad time value in ACL condition "
1842 "\"verify %s\"", arg);
1848 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1849 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1850 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1851 case CALLOUT_MAILFROM:
1852 if (!verify_header_sender)
1854 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1855 "callout option only for verify=header_sender (detected in ACL "
1856 "condition \"%s\")", arg);
1859 se_mailfrom = string_copy(opt);
1861 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1862 case CALLOUT_MAXWAIT: callout_overall = period; break;
1863 case CALLOUT_CONNECT: callout_connect = period; break;
1864 case CALLOUT_TIME: callout = period; break;
1870 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1871 "ACL condition \"%s\"", arg);
1877 /* Option not recognized */
1881 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1882 "condition \"verify %s\"", ss, arg);
1887 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1888 (vopt_callout_recipsender|vopt_callout_recippmaster))
1890 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1891 "for a recipient callout";
1895 /* Handle sender-in-header verification. Default the user message to the log
1896 message if giving out verification details. */
1898 if (verify_header_sender)
1902 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1903 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1906 *basic_errno = verrno;
1907 if (smtp_return_error_details)
1909 if (!*user_msgptr && *log_msgptr)
1910 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1911 if (rc == DEFER) acl_temp_details = TRUE;
1916 /* Handle a sender address. The default is to verify *the* sender address, but
1917 optionally a different address can be given, for special requirements. If the
1918 address is empty, we are dealing with a bounce message that has no sender, so
1919 we cannot do any checking. If the real sender address gets rewritten during
1920 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1921 during message reception.
1923 A list of verified "sender" addresses is kept to try to avoid doing to much
1924 work repetitively when there are multiple recipients in a message and they all
1925 require sender verification. However, when callouts are involved, it gets too
1926 complicated because different recipients may require different callout options.
1927 Therefore, we always do a full sender verify when any kind of callout is
1928 specified. Caching elsewhere, for instance in the DNS resolver and in the
1929 callout handling, should ensure that this is not terribly inefficient. */
1931 else if (verify_sender_address)
1933 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1935 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1936 "sender verify callout";
1940 sender_vaddr = verify_checked_sender(verify_sender_address);
1941 if (sender_vaddr != NULL && /* Previously checked */
1942 callout <= 0) /* No callout needed this time */
1944 /* If the "routed" flag is set, it means that routing worked before, so
1945 this check can give OK (the saved return code value, if set, belongs to a
1946 callout that was done previously). If the "routed" flag is not set, routing
1947 must have failed, so we use the saved return code. */
1949 if (testflag(sender_vaddr, af_verify_routed))
1953 rc = sender_vaddr->special_action;
1954 *basic_errno = sender_vaddr->basic_errno;
1956 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1959 /* Do a new verification, and cache the result. The cache is used to avoid
1960 verifying the sender multiple times for multiple RCPTs when callouts are not
1961 specified (see comments above).
1963 The cache is also used on failure to give details in response to the first
1964 RCPT that gets bounced for this reason. However, this can be suppressed by
1965 the no_details option, which sets the flag that says "this detail has already
1966 been sent". The cache normally contains just one address, but there may be
1967 more in esoteric circumstances. */
1972 uschar *save_address_data = deliver_address_data;
1974 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1976 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1978 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1979 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1982 if (no_details) setflag(sender_vaddr, af_sverify_told);
1983 if (verify_sender_address[0] != 0)
1985 /* If this is the real sender address, save the unrewritten version
1986 for use later in receive. Otherwise, set a flag so that rewriting the
1987 sender in verify_address() does not update sender_address. */
1989 if (verify_sender_address == sender_address)
1990 sender_address_unrewritten = sender_address;
1992 verify_options |= vopt_fake_sender;
1994 if (success_on_redirect)
1995 verify_options |= vopt_success_on_redirect;
1997 /* The recipient, qualify, and expn options are never set in
2000 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
2001 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
2003 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2006 *basic_errno = sender_vaddr->basic_errno;
2010 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
2011 debug_printf_indent("sender %s verified ok as %s\n",
2012 verify_sender_address, sender_vaddr->address);
2014 debug_printf_indent("sender %s verified ok\n",
2015 verify_sender_address);
2019 rc = OK; /* Null sender */
2021 /* Cache the result code */
2023 if (routed) setflag(sender_vaddr, af_verify_routed);
2024 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2025 sender_vaddr->special_action = rc;
2026 sender_vaddr->next = sender_verified_list;
2027 sender_verified_list = sender_vaddr;
2029 /* Restore the recipient address data, which might have been clobbered by
2030 the sender verification. */
2032 deliver_address_data = save_address_data;
2035 /* Put the sender address_data value into $sender_address_data */
2037 sender_address_data = sender_vaddr->prop.address_data;
2040 /* A recipient address just gets a straightforward verify; again we must handle
2041 the DEFER overrides. */
2047 if (success_on_redirect)
2048 verify_options |= vopt_success_on_redirect;
2050 /* We must use a copy of the address for verification, because it might
2054 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2055 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2056 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2058 *basic_errno = addr2.basic_errno;
2059 *log_msgptr = addr2.message;
2060 *user_msgptr = (addr2.user_message != NULL)?
2061 addr2.user_message : addr2.message;
2063 /* Allow details for temporary error if the address is so flagged. */
2064 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
2066 /* Make $address_data visible */
2067 deliver_address_data = addr2.prop.address_data;
2070 /* We have a result from the relevant test. Handle defer overrides first. */
2072 if (rc == DEFER && (defer_ok ||
2073 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2075 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2076 defer_ok? "defer_ok" : "callout_defer_ok");
2080 /* If we've failed a sender, set up a recipient message, and point
2081 sender_verified_failed to the address item that actually failed. */
2083 if (rc != OK && verify_sender_address != NULL)
2086 *log_msgptr = *user_msgptr = US"Sender verify failed";
2087 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2088 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2091 *log_msgptr = US"Could not complete sender verify callout";
2092 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2096 sender_verified_failed = sender_vaddr;
2099 /* Verifying an address messes up the values of $domain and $local_part,
2100 so reset them before returning if this is a RCPT ACL. */
2104 deliver_domain = addr->domain;
2105 deliver_localpart = addr->local_part;
2109 /* Syntax errors in the verify argument come here. */
2112 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2113 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2114 "or \"reverse_host_lookup\" at start of ACL condition "
2115 "\"verify %s\"", arg);
2122 /*************************************************
2123 * Check argument for control= modifier *
2124 *************************************************/
2126 /* Called from acl_check_condition() below
2129 arg the argument string for control=
2130 pptr set to point to the terminating character
2131 where which ACL we are in
2132 log_msgptr for error messages
2134 Returns: CONTROL_xxx value
2138 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2143 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2144 || ( arg[len = Ustrlen((d = controls_list+idx)->name)] != 0
2145 && (!d->has_option || arg[len] != '/')
2148 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2149 return CONTROL_ERROR;
2159 /*************************************************
2160 * Return a ratelimit error *
2161 *************************************************/
2163 /* Called from acl_ratelimit() below
2166 log_msgptr for error messages
2167 format format string
2168 ... supplementary arguments
2169 ss ratelimit option name
2170 where ACL_WHERE_xxxx indicating which ACL this is
2176 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2179 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2180 va_start(ap, format);
2181 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2182 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2183 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2185 *log_msgptr = string_sprintf(
2186 "error in arguments to \"ratelimit\" condition: %s", buffer);
2193 /*************************************************
2194 * Handle rate limiting *
2195 *************************************************/
2197 /* Called by acl_check_condition() below to calculate the result
2198 of the ACL ratelimit condition.
2200 Note that the return value might be slightly unexpected: if the
2201 sender's rate is above the limit then the result is OK. This is
2202 similar to the dnslists condition, and is so that you can write
2203 ACL clauses like: defer ratelimit = 15 / 1h
2206 arg the option string for ratelimit=
2207 where ACL_WHERE_xxxx indicating which ACL this is
2208 log_msgptr for error messages
2210 Returns: OK - Sender's rate is above limit
2211 FAIL - Sender's rate is below limit
2212 DEFER - Problem opening ratelimit database
2213 ERROR - Syntax error in options.
2217 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2219 double limit, period, count;
2222 uschar *unique = NULL;
2224 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2225 BOOL noupdate = FALSE, badacl = FALSE;
2226 int mode = RATE_PER_WHAT;
2228 tree_node **anchor, *t;
2229 open_db dbblock, *dbm;
2231 dbdata_ratelimit *dbd;
2232 dbdata_ratelimit_unique *dbdb;
2235 /* Parse the first two options and record their values in expansion
2236 variables. These variables allow the configuration to have informative
2237 error messages based on rate limits obtained from a table lookup. */
2239 /* First is the maximum number of messages per period / maximum burst
2240 size, which must be greater than or equal to zero. Zero is useful for
2241 rate measurement as opposed to rate limiting. */
2243 if (!(sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0)))
2244 return ratelimit_error(log_msgptr, "sender rate limit not set");
2246 limit = Ustrtod(sender_rate_limit, &ss);
2247 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2248 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2249 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2251 if (limit < 0.0 || *ss != '\0')
2252 return ratelimit_error(log_msgptr,
2253 "\"%s\" is not a positive number", sender_rate_limit);
2255 /* Second is the rate measurement period / exponential smoothing time
2256 constant. This must be strictly greater than zero, because zero leads to
2257 run-time division errors. */
2259 period = !(sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0))
2260 ? -1.0 : readconf_readtime(sender_rate_period, 0, FALSE);
2262 return ratelimit_error(log_msgptr,
2263 "\"%s\" is not a time value", sender_rate_period);
2265 /* By default we are counting one of something, but the per_rcpt,
2266 per_byte, and count options can change this. */
2270 /* Parse the other options. */
2272 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size)))
2274 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2275 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2276 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2277 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2278 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2279 else if (strcmpic(ss, US"per_conn") == 0)
2281 RATE_SET(mode, PER_CONN);
2282 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2285 else if (strcmpic(ss, US"per_mail") == 0)
2287 RATE_SET(mode, PER_MAIL);
2288 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2290 else if (strcmpic(ss, US"per_rcpt") == 0)
2292 /* If we are running in the RCPT ACL, then we'll count the recipients
2293 one by one, but if we are running when we have accumulated the whole
2294 list then we'll add them all in one batch. */
2295 if (where == ACL_WHERE_RCPT)
2296 RATE_SET(mode, PER_RCPT);
2297 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2298 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2299 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2300 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2302 else if (strcmpic(ss, US"per_byte") == 0)
2304 /* If we have not yet received the message data and there was no SIZE
2305 declaration on the MAIL command, then it's safe to just use a value of
2306 zero and let the recorded rate decay as if nothing happened. */
2307 RATE_SET(mode, PER_MAIL);
2308 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2309 else count = message_size < 0 ? 0.0 : (double)message_size;
2311 else if (strcmpic(ss, US"per_addr") == 0)
2313 RATE_SET(mode, PER_RCPT);
2314 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2315 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2317 else if (strncmpic(ss, US"count=", 6) == 0)
2320 count = Ustrtod(ss+6, &e);
2321 if (count < 0.0 || *e != '\0')
2322 return ratelimit_error(log_msgptr, "\"%s\" is not a positive number", ss);
2324 else if (strncmpic(ss, US"unique=", 7) == 0)
2325 unique = string_copy(ss + 7);
2327 key = string_copy(ss);
2329 key = string_sprintf("%s/%s", key, ss);
2332 /* Sanity check. When the badacl flag is set the update mode must either
2333 be readonly (which is the default if it is omitted) or, for backwards
2334 compatibility, a combination of noupdate and strict or leaky. */
2336 if (mode == RATE_PER_CLASH)
2337 return ratelimit_error(log_msgptr, "conflicting per_* options");
2338 if (leaky + strict + readonly > 1)
2339 return ratelimit_error(log_msgptr, "conflicting update modes");
2340 if (badacl && (leaky || strict) && !noupdate)
2341 return ratelimit_error(log_msgptr,
2342 "\"%s\" must not have /leaky or /strict option in %s ACL",
2343 ratelimit_option_string[mode], acl_wherenames[where]);
2345 /* Set the default values of any unset options. In readonly mode we
2346 perform the rate computation without any increment so that its value
2347 decays to eventually allow over-limit senders through. */
2349 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2350 if (badacl) readonly = TRUE;
2351 if (readonly) count = 0.0;
2352 if (!strict && !readonly) leaky = TRUE;
2353 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2355 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2356 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2357 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2358 are added to the key because they alter the meaning of the stored data. */
2361 key = !sender_host_address ? US"" : sender_host_address;
2363 key = string_sprintf("%s/%s/%s%s",
2365 ratelimit_option_string[mode],
2366 unique == NULL ? "" : "unique/",
2370 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2372 /* See if we have already computed the rate by looking in the relevant tree.
2373 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2374 pool so that they survive across resets. In readonly mode we only remember the
2375 result for the rest of this command in case a later command changes it. After
2376 this bit of logic the code is independent of the per_* mode. */
2378 old_pool = store_pool;
2381 anchor = &ratelimiters_cmd;
2385 anchor = &ratelimiters_conn;
2386 store_pool = POOL_PERM;
2390 case RATE_PER_ALLRCPTS:
2391 anchor = &ratelimiters_mail;
2396 anchor = &ratelimiters_cmd;
2399 anchor = NULL; /* silence an "unused" complaint */
2400 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2401 "internal ACL error: unknown ratelimit mode %d", mode);
2405 if ((t = tree_search(*anchor, key)))
2408 /* The following few lines duplicate some of the code below. */
2409 rc = (dbd->rate < limit)? FAIL : OK;
2410 store_pool = old_pool;
2411 sender_rate = string_sprintf("%.1f", dbd->rate);
2413 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2417 /* We aren't using a pre-computed rate, so get a previously recorded rate
2418 from the database, which will be updated and written back if required. */
2420 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE)))
2422 store_pool = old_pool;
2424 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2425 *log_msgptr = US"ratelimit database not available";
2428 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2431 gettimeofday(&tv, NULL);
2435 /* Locate the basic ratelimit block inside the DB data. */
2436 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2439 /* Forget the old Bloom filter if it is too old, so that we count each
2440 repeating event once per period. We don't simply clear and re-use the old
2441 filter because we want its size to change if the limit changes. Note that
2442 we keep the dbd pointer for copying the rate into the new data block. */
2444 if(unique && tv.tv_sec > dbdb->bloom_epoch + period)
2446 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2452 if(unique && dbdb_size < sizeof(*dbdb))
2454 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2459 /* Allocate a new data block if the database lookup failed
2460 or the Bloom filter passed its age limit. */
2466 /* No Bloom filter. This basic ratelimit block is initialized below. */
2467 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2468 dbdb_size = sizeof(*dbd);
2469 dbdb = store_get(dbdb_size);
2474 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2476 /* See the long comment below for an explanation of the magic number 2.
2477 The filter has a minimum size in case the rate limit is very small;
2478 this is determined by the definition of dbdata_ratelimit_unique. */
2480 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2481 if (extra < 0) extra = 0;
2482 dbdb_size = sizeof(*dbdb) + extra;
2483 dbdb = store_get(dbdb_size);
2484 dbdb->bloom_epoch = tv.tv_sec;
2485 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2486 memset(dbdb->bloom, 0, dbdb->bloom_size);
2488 /* Preserve any basic ratelimit data (which is our longer-term memory)
2489 by copying it from the discarded block. */
2499 /* If we are counting unique events, find out if this event is new or not.
2500 If the client repeats the event during the current period then it should be
2501 counted. We skip this code in readonly mode for efficiency, because any
2502 changes to the filter will be discarded and because count is already set to
2505 if (unique && !readonly)
2507 /* We identify unique events using a Bloom filter. (You can find my
2508 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2509 With the per_addr option, an "event" is a recipient address, though the
2510 user can use the unique option to define their own events. We only count
2511 an event if we have not seen it before.
2513 We size the filter according to the rate limit, which (in leaky mode)
2514 is the limit on the population of the filter. We allow 16 bits of space
2515 per entry (see the construction code above) and we set (up to) 8 of them
2516 when inserting an element (see the loop below). The probability of a false
2517 positive (an event we have not seen before but which we fail to count) is
2521 allzero = exp(-numhash * pop / size)
2522 = exp(-0.5 * pop / limit)
2523 fpr = pow(1 - allzero, numhash)
2525 For senders at the limit the fpr is 0.06% or 1 in 1700
2526 and for senders at half the limit it is 0.0006% or 1 in 170000
2528 In strict mode the Bloom filter can fill up beyond the normal limit, in
2529 which case the false positive rate will rise. This means that the
2530 measured rate for very fast senders can bogusly drop off after a while.
2532 At twice the limit, the fpr is 2.5% or 1 in 40
2533 At four times the limit, it is 31% or 1 in 3.2
2535 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2536 decay below the limit, and if this is more than one then the Bloom filter
2537 will be discarded before the decay gets that far. The false positive rate
2538 at this threshold is 9.3% or 1 in 10.7. */
2541 unsigned n, hash, hinc;
2545 /* Instead of using eight independent hash values, we combine two values
2546 using the formula h1 + n * h2. This does not harm the Bloom filter's
2547 performance, and means the amount of hash we need is independent of the
2548 number of bits we set in the filter. */
2550 md5_start(&md5info);
2551 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2552 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2553 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2555 /* Scan the bits corresponding to this event. A zero bit means we have
2556 not seen it before. Ensure all bits are set to record this event. */
2558 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2561 for (n = 0; n < 8; n++, hash += hinc)
2563 int bit = 1 << (hash % 8);
2564 int byte = (hash / 8) % dbdb->bloom_size;
2565 if ((dbdb->bloom[byte] & bit) == 0)
2567 dbdb->bloom[byte] |= bit;
2572 /* If this event has occurred before, do not count it. */
2576 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2580 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2583 /* If there was no previous ratelimit data block for this key, initialize
2584 the new one, otherwise update the block from the database. The initial rate
2585 is what would be computed by the code below for an infinite interval. */
2589 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2591 dbd->time_stamp = tv.tv_sec;
2592 dbd->time_usec = tv.tv_usec;
2597 /* The smoothed rate is computed using an exponentially weighted moving
2598 average adjusted for variable sampling intervals. The standard EWMA for
2599 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2600 where f() is the measured value and f'() is the smoothed value.
2602 Old data decays out of the smoothed value exponentially, such that data n
2603 samples old is multiplied by a^n. The exponential decay time constant p
2604 is defined such that data p samples old is multiplied by 1/e, which means
2605 that a = exp(-1/p). We can maintain the same time constant for a variable
2606 sampling interval i by using a = exp(-i/p).
2608 The rate we are measuring is messages per period, suitable for directly
2609 comparing with the limit. The average rate between now and the previous
2610 message is period / interval, which we feed into the EWMA as the sample.
2612 It turns out that the number of messages required for the smoothed rate
2613 to reach the limit when they are sent in a burst is equal to the limit.
2614 This can be seen by analysing the value of the smoothed rate after N
2615 messages sent at even intervals. Let k = (1 - a) * p/i
2617 rate_1 = (1 - a) * p/i + a * rate_0
2619 rate_2 = k + a * rate_1
2620 = k + a * k + a^2 * rate_0
2621 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2622 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2623 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2624 = rate_0 * a^N + p/i * (1 - a^N)
2626 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2628 rate_N = p/i + (rate_0 - p/i) * a^N
2629 a^N = (rate_N - p/i) / (rate_0 - p/i)
2630 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2631 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2633 Numerical analysis of the above equation, setting the computed rate to
2634 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2635 rates, p/i, the number of messages N = limit. So limit serves as both the
2636 maximum rate measured in messages per period, and the maximum number of
2637 messages that can be sent in a fast burst. */
2639 double this_time = (double)tv.tv_sec
2640 + (double)tv.tv_usec / 1000000.0;
2641 double prev_time = (double)dbd->time_stamp
2642 + (double)dbd->time_usec / 1000000.0;
2644 /* We must avoid division by zero, and deal gracefully with the clock going
2645 backwards. If we blunder ahead when time is in reverse then the computed
2646 rate will be bogus. To be safe we clamp interval to a very small number. */
2648 double interval = this_time - prev_time <= 0.0 ? 1e-9
2649 : this_time - prev_time;
2651 double i_over_p = interval / period;
2652 double a = exp(-i_over_p);
2654 /* Combine the instantaneous rate (period / interval) with the previous rate
2655 using the smoothing factor a. In order to measure sized events, multiply the
2656 instantaneous rate by the count of bytes or recipients etc. */
2658 dbd->time_stamp = tv.tv_sec;
2659 dbd->time_usec = tv.tv_usec;
2660 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2662 /* When events are very widely spaced the computed rate tends towards zero.
2663 Although this is accurate it turns out not to be useful for our purposes,
2664 especially when the first event after a long silence is the start of a spam
2665 run. A more useful model is that the rate for an isolated event should be the
2666 size of the event per the period size, ignoring the lack of events outside
2667 the current period and regardless of where the event falls in the period. So,
2668 if the interval was so long that the calculated rate is unhelpfully small, we
2669 re-initialize the rate. In the absence of higher-rate bursts, the condition
2670 below is true if the interval is greater than the period. */
2672 if (dbd->rate < count) dbd->rate = count;
2675 /* Clients sending at the limit are considered to be over the limit.
2676 This matters for edge cases such as a limit of zero, when the client
2677 should be completely blocked. */
2679 rc = dbd->rate < limit ? FAIL : OK;
2681 /* Update the state if the rate is low or if we are being strict. If we
2682 are in leaky mode and the sender's rate is too high, we do not update
2683 the recorded rate in order to avoid an over-aggressive sender's retry
2684 rate preventing them from getting any email through. If readonly is set,
2685 neither leaky nor strict are set, so we do not do any updates. */
2687 if ((rc == FAIL && leaky) || strict)
2689 dbfn_write(dbm, key, dbdb, dbdb_size);
2690 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2694 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2695 readonly? "readonly mode" : "over the limit, but leaky");
2700 /* Store the result in the tree for future reference. */
2702 t = store_get(sizeof(tree_node) + Ustrlen(key));
2704 Ustrcpy(t->name, key);
2705 (void)tree_insertnode(anchor, t);
2707 /* We create the formatted version of the sender's rate very late in
2708 order to ensure that it is done using the correct storage pool. */
2710 store_pool = old_pool;
2711 sender_rate = string_sprintf("%.1f", dbd->rate);
2714 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2721 /*************************************************
2722 * The udpsend ACL modifier *
2723 *************************************************/
2725 /* Called by acl_check_condition() below.
2728 arg the option string for udpsend=
2729 log_msgptr for error messages
2731 Returns: OK - Completed.
2732 DEFER - Problem with DNS lookup.
2733 ERROR - Syntax error in options.
2737 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2749 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2750 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2754 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2759 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2764 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2767 portnum = Ustrtol(portstr, &portend, 10);
2768 if (*portend != '\0')
2770 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2774 /* Make a single-item host list. */
2775 h = store_get(sizeof(host_item));
2776 memset(h, 0, sizeof(host_item));
2781 if (string_is_ip_address(hostname, NULL))
2782 h->address = hostname, r = HOST_FOUND;
2784 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2785 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2787 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2792 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2794 /*XXX this could better use sendto */
2795 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2796 1, NULL, &errstr, NULL);
2797 if (r < 0) goto defer;
2799 r = send(s, arg, len, 0);
2802 errstr = US strerror(errno);
2810 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2815 debug_printf_indent("udpsend %d bytes\n", r);
2820 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2826 /*************************************************
2827 * Handle conditions/modifiers on an ACL item *
2828 *************************************************/
2830 /* Called from acl_check() below.
2834 cb ACL condition block - if NULL, result is OK
2835 where where called from
2836 addr the address being checked for RCPT, or NULL
2837 level the nesting level
2838 epp pointer to pass back TRUE if "endpass" encountered
2839 (applies only to "accept" and "discard")
2840 user_msgptr user message pointer
2841 log_msgptr log message pointer
2842 basic_errno pointer to where to put verify error
2844 Returns: OK - all conditions are met
2845 DISCARD - an "acl" condition returned DISCARD - only allowed
2846 for "accept" or "discard" verbs
2847 FAIL - at least one condition fails
2848 FAIL_DROP - an "acl" condition returned FAIL_DROP
2849 DEFER - can't tell at the moment (typically, lookup defer,
2850 but can be temporary callout problem)
2851 ERROR - ERROR from nested ACL or expansion failure or other
2856 acl_check_condition(int verb, acl_condition_block *cb, int where,
2857 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2858 uschar **log_msgptr, int *basic_errno)
2860 uschar *user_message = NULL;
2861 uschar *log_message = NULL;
2863 #ifdef WITH_CONTENT_SCAN
2867 for (; cb != NULL; cb = cb->next)
2872 /* The message and log_message items set up messages to be used in
2873 case of rejection. They are expanded later. */
2875 if (cb->type == ACLC_MESSAGE)
2877 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2878 user_message = cb->arg;
2882 if (cb->type == ACLC_LOG_MESSAGE)
2884 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2885 log_message = cb->arg;
2889 /* The endpass "condition" just sets a flag to show it occurred. This is
2890 checked at compile time to be on an "accept" or "discard" item. */
2892 if (cb->type == ACLC_ENDPASS)
2898 /* For other conditions and modifiers, the argument is expanded now for some
2899 of them, but not for all, because expansion happens down in some lower level
2900 checking functions in some cases. */
2902 if (!conditions[cb->type].expand_at_top)
2904 else if (!(arg = expand_string(cb->arg)))
2906 if (expand_string_forcedfail) continue;
2907 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2908 cb->arg, expand_string_message);
2909 return search_find_defer ? DEFER : ERROR;
2912 /* Show condition, and expanded condition if it's different */
2917 debug_printf_indent("check %s%s %n",
2918 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2919 conditions[cb->type].name, &lhswidth);
2921 if (cb->type == ACLC_SET)
2923 #ifndef DISABLE_DKIM
2924 if ( Ustrcmp(cb->u.varname, "dkim_verify_status") == 0
2925 || Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
2927 debug_printf("%s ", cb->u.varname);
2933 debug_printf("acl_%s ", cb->u.varname);
2934 lhswidth += 5 + Ustrlen(cb->u.varname);
2938 debug_printf("= %s\n", cb->arg);
2941 debug_printf("%.*s= %s\n", lhswidth,
2945 /* Check that this condition makes sense at this time */
2947 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2949 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2950 conditions[cb->type].is_modifier ? "use" : "test",
2951 conditions[cb->type].name, acl_wherenames[where]);
2955 /* Run the appropriate test for each condition, or take the appropriate
2956 action for the remaining modifiers. */
2960 case ACLC_ADD_HEADER:
2964 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2968 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2969 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2971 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2972 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2978 case ACLC_AUTHENTICATED:
2979 rc = sender_host_authenticated ? match_isinlist(sender_host_authenticated,
2980 &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL) : FAIL;
2983 #ifdef EXPERIMENTAL_BRIGHTMAIL
2984 case ACLC_BMI_OPTIN:
2986 int old_pool = store_pool;
2987 store_pool = POOL_PERM;
2988 bmi_current_optin = string_copy(arg);
2989 store_pool = old_pool;
2994 case ACLC_CONDITION:
2995 /* The true/false parsing here should be kept in sync with that used in
2996 expand.c when dealing with ECOND_BOOL so that we don't have too many
2997 different definitions of what can be a boolean. */
2999 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
3000 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
3001 rc = (Uatoi(arg) == 0)? FAIL : OK;
3003 rc = (strcmpic(arg, US"no") == 0 ||
3004 strcmpic(arg, US"false") == 0)? FAIL :
3005 (strcmpic(arg, US"yes") == 0 ||
3006 strcmpic(arg, US"true") == 0)? OK : DEFER;
3008 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
3011 case ACLC_CONTINUE: /* Always succeeds */
3016 const uschar *p = NULL;
3017 control_type = decode_control(arg, &p, where, log_msgptr);
3019 /* Check if this control makes sense at this time */
3021 if (controls_list[control_type].forbids & (1 << where))
3023 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
3024 controls_list[control_type].name, acl_wherenames[where]);
3028 switch(control_type)
3030 case CONTROL_AUTH_UNADVERTISED:
3031 allow_auth_unadvertised = TRUE;
3034 #ifdef EXPERIMENTAL_BRIGHTMAIL
3035 case CONTROL_BMI_RUN:
3040 #ifndef DISABLE_DKIM
3041 case CONTROL_DKIM_VERIFY:
3042 dkim_disable_verify = TRUE;
3043 #ifdef EXPERIMENTAL_DMARC
3044 /* Since DKIM was blocked, skip DMARC too */
3045 dmarc_disable_verify = TRUE;
3046 dmarc_enable_forensic = FALSE;
3051 #ifdef EXPERIMENTAL_DMARC
3052 case CONTROL_DMARC_VERIFY:
3053 dmarc_disable_verify = TRUE;
3056 case CONTROL_DMARC_FORENSIC:
3057 dmarc_enable_forensic = TRUE;
3064 int fd, af, level, optname, value;
3065 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3066 a socket; we can accept that, we'll just debug-log failures anyway. */
3067 fd = fileno(smtp_in);
3068 af = ip_get_address_family(fd);
3072 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3076 if (dscp_lookup(p+1, af, &level, &optname, &value))
3078 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3080 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3081 p+1, strerror(errno));
3085 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3090 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3096 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3104 case CONTROL_CASEFUL_LOCAL_PART:
3105 deliver_localpart = addr->cc_local_part;
3108 case CONTROL_CASELOWER_LOCAL_PART:
3109 deliver_localpart = addr->lc_local_part;
3112 case CONTROL_ENFORCE_SYNC:
3113 smtp_enforce_sync = TRUE;
3116 case CONTROL_NO_ENFORCE_SYNC:
3117 smtp_enforce_sync = FALSE;
3120 #ifdef WITH_CONTENT_SCAN
3121 case CONTROL_NO_MBOX_UNSPOOL:
3122 no_mbox_unspool = TRUE;
3126 case CONTROL_NO_MULTILINE:
3127 no_multiline_responses = TRUE;
3130 case CONTROL_NO_PIPELINING:
3131 pipelining_enable = FALSE;
3134 case CONTROL_NO_DELAY_FLUSH:
3135 disable_delay_flush = TRUE;
3138 case CONTROL_NO_CALLOUT_FLUSH:
3139 disable_callout_flush = TRUE;
3142 case CONTROL_FAKEREJECT:
3143 cancel_cutthrough_connection(TRUE, US"fakereject");
3144 case CONTROL_FAKEDEFER:
3145 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3148 const uschar *pp = p + 1;
3149 while (*pp != 0) pp++;
3150 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3155 /* Explicitly reset to default string */
3156 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).";
3160 case CONTROL_FREEZE:
3161 deliver_freeze = TRUE;
3162 deliver_frozen_at = time(NULL);
3163 freeze_tell = freeze_tell_config; /* Reset to configured value */
3164 if (Ustrncmp(p, "/no_tell", 8) == 0)
3171 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3174 cancel_cutthrough_connection(TRUE, US"item frozen");
3177 case CONTROL_QUEUE_ONLY:
3178 queue_only_policy = TRUE;
3179 cancel_cutthrough_connection(TRUE, US"queueing forced");
3182 case CONTROL_SUBMISSION:
3183 originator_name = US"";
3184 submission_mode = TRUE;
3187 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3190 active_local_sender_retain = TRUE;
3191 active_local_from_check = FALSE;
3193 else if (Ustrncmp(p, "/domain=", 8) == 0)
3195 const uschar *pp = p + 8;
3196 while (*pp != 0 && *pp != '/') pp++;
3197 submission_domain = string_copyn(p+8, pp-p-8);
3200 /* The name= option must be last, because it swallows the rest of
3202 else if (Ustrncmp(p, "/name=", 6) == 0)
3204 const uschar *pp = p + 6;
3205 while (*pp != 0) pp++;
3206 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3207 big_buffer, big_buffer_size));
3214 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3221 uschar * debug_tag = NULL;
3222 uschar * debug_opts = NULL;
3227 const uschar * pp = p+1;
3228 if (Ustrncmp(pp, "tag=", 4) == 0)
3230 for (pp += 4; *pp && *pp != '/';) pp++;
3231 debug_tag = string_copyn(p+5, pp-p-5);
3233 else if (Ustrncmp(pp, "opts=", 5) == 0)
3235 for (pp += 5; *pp && *pp != '/';) pp++;
3236 debug_opts = string_copyn(p+6, pp-p-6);
3238 else if (Ustrncmp(pp, "kill", 4) == 0)
3240 for (pp += 4; *pp && *pp != '/';) pp++;
3244 while (*pp && *pp != '/') pp++;
3249 debug_logging_stop();
3251 debug_logging_activate(debug_tag, debug_opts);
3255 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3256 suppress_local_fixups = TRUE;
3259 case CONTROL_CUTTHROUGH_DELIVERY:
3261 uschar * ignored = NULL;
3262 #ifndef DISABLE_PRDR
3267 /* Too hard to think about for now. We might in future cutthrough
3268 the case where both sides handle prdr and this-node prdr acl
3270 ignored = US"PRDR active";
3274 ignored = US"frozen";
3275 else if (queue_only_policy)
3276 ignored = US"queue-only";
3277 else if (fake_response == FAIL)
3278 ignored = US"fakereject";
3281 if (rcpt_count == 1)
3283 cutthrough.delivery = TRUE; /* control accepted */
3286 const uschar * pp = p+1;
3287 if (Ustrncmp(pp, "defer=", 6) == 0)
3290 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3291 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3294 while (*pp && *pp != '/') pp++;
3299 ignored = US"nonfirst rcpt";
3302 DEBUG(D_acl) if (ignored)
3303 debug_printf(" cutthrough request ignored on %s item\n", ignored);
3308 case CONTROL_UTF8_DOWNCONVERT:
3313 message_utf8_downconvert = 1;
3314 addr->prop.utf8_downcvt = TRUE;
3315 addr->prop.utf8_downcvt_maybe = FALSE;
3321 message_utf8_downconvert = 0;
3322 addr->prop.utf8_downcvt = FALSE;
3323 addr->prop.utf8_downcvt_maybe = FALSE;
3327 if (p[1] == '-' && p[2] == '1')
3329 message_utf8_downconvert = -1;
3330 addr->prop.utf8_downcvt = FALSE;
3331 addr->prop.utf8_downcvt_maybe = TRUE;
3335 *log_msgptr = US"bad option value for control=utf8_downconvert";
3339 message_utf8_downconvert = 1;
3340 addr->prop.utf8_downcvt = TRUE;
3341 addr->prop.utf8_downcvt_maybe = FALSE;
3351 #ifdef EXPERIMENTAL_DCC
3354 /* Separate the regular expression and any optional parameters. */
3355 const uschar * list = arg;
3356 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3357 /* Run the dcc backend. */
3358 rc = dcc_process(&ss);
3359 /* Modify return code based upon the existence of options. */
3360 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3361 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3362 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3367 #ifdef WITH_CONTENT_SCAN
3369 rc = mime_decode(&arg);
3375 int delay = readconf_readtime(arg, 0, FALSE);
3378 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3379 "modifier: \"%s\" is not a time value", arg);
3384 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3389 debug_printf_indent("delay skipped in -bh checking mode\n");
3392 /* NOTE 1: Remember that we may be
3393 dealing with stdin/stdout here, in addition to TCP/IP connections.
3394 Also, delays may be specified for non-SMTP input, where smtp_out and
3395 smtp_in will be NULL. Whatever is done must work in all cases.
3397 NOTE 2: The added feature of flushing the output before a delay must
3398 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3403 if (smtp_out != NULL && !disable_delay_flush)
3406 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3412 p.fd = fileno(smtp_out);
3413 p.events = POLLRDHUP;
3416 if (poll(&p, n, delay*1000) > 0)
3417 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3420 /* It appears to be impossible to detect that a TCP/IP connection has
3421 gone away without reading from it. This means that we cannot shorten
3422 the delay below if the client goes away, because we cannot discover
3423 that the client has closed its end of the connection. (The connection
3424 is actually in a half-closed state, waiting for the server to close its
3425 end.) It would be nice to be able to detect this state, so that the
3426 Exim process is not held up unnecessarily. However, it seems that we
3427 can't. The poll() function does not do the right thing, and in any case
3428 it is not always available.
3431 while (delay > 0) delay = sleep(delay);
3438 #ifndef DISABLE_DKIM
3439 case ACLC_DKIM_SIGNER:
3440 if (dkim_cur_signer)
3441 rc = match_isinlist(dkim_cur_signer,
3442 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3447 case ACLC_DKIM_STATUS:
3448 rc = match_isinlist(dkim_verify_status,
3449 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3453 #ifdef EXPERIMENTAL_DMARC
3454 case ACLC_DMARC_STATUS:
3455 if (!dmarc_has_been_checked)
3457 dmarc_has_been_checked = TRUE;
3458 /* used long way of dmarc_exim_expand_query() in case we need more
3459 * view into the process in the future. */
3460 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3461 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3466 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3470 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3471 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3474 /* The value in tls_cipher is the full cipher name, for example,
3475 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3476 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3477 what may in practice come out of the SSL library - which at the time of
3478 writing is poorly documented. */
3480 case ACLC_ENCRYPTED:
3481 if (tls_in.cipher == NULL) rc = FAIL; else
3483 uschar *endcipher = NULL;
3484 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3485 if (cipher == NULL) cipher = tls_in.cipher; else
3487 endcipher = Ustrchr(++cipher, ':');
3488 if (endcipher != NULL) *endcipher = 0;
3490 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3491 if (endcipher != NULL) *endcipher = ':';
3495 /* Use verify_check_this_host() instead of verify_check_host() so that
3496 we can pass over &host_data to catch any looked up data. Once it has been
3497 set, it retains its value so that it's still there if another ACL verb
3498 comes through here and uses the cache. However, we must put it into
3499 permanent store in case it is also expected to be used in a subsequent
3500 message in the same SMTP connection. */
3503 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3504 (sender_host_address == NULL)? US"" : sender_host_address,
3506 if (rc == DEFER) *log_msgptr = search_error_message;
3507 if (host_data) host_data = string_copy_malloc(host_data);
3510 case ACLC_LOCAL_PARTS:
3511 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3512 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3513 CUSS &deliver_localpart_data);
3516 case ACLC_LOG_REJECT_TARGET:
3520 const uschar *s = arg;
3522 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3524 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3525 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3526 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3529 logbits |= LOG_MAIN|LOG_REJECT;
3530 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3531 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3534 log_reject_target = logbits;
3541 const uschar *s = arg;
3547 if (Ustrncmp(s, "main", 4) == 0)
3548 { logbits |= LOG_MAIN; s += 4; }
3549 else if (Ustrncmp(s, "panic", 5) == 0)
3550 { logbits |= LOG_PANIC; s += 5; }
3551 else if (Ustrncmp(s, "reject", 6) == 0)
3552 { logbits |= LOG_REJECT; s += 6; }
3555 logbits = LOG_MAIN|LOG_PANIC;
3556 s = string_sprintf(":unknown log name in \"%s\" in "
3557 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3563 while (isspace(*s)) s++;
3566 if (logbits == 0) logbits = LOG_MAIN;
3567 log_write(0, logbits, "%s", string_printing(s));
3571 #ifdef WITH_CONTENT_SCAN
3572 case ACLC_MALWARE: /* Run the malware backend. */
3574 /* Separate the regular expression and any optional parameters. */
3575 const uschar * list = arg;
3576 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3578 BOOL defer_ok = FALSE;
3581 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3582 if (strcmpic(opt, US"defer_ok") == 0)
3584 else if ( strncmpic(opt, US"tmo=", 4) == 0
3585 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3588 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3592 rc = malware(ss, timeout);
3593 if (rc == DEFER && defer_ok)
3594 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3598 case ACLC_MIME_REGEX:
3599 rc = mime_regex(&arg);
3604 if (Ustrchr(arg, '/'))
3606 *log_msgptr = string_sprintf(
3607 "Directory separator not permitted in queue name: '%s'", arg);
3610 queue_name = string_copy_malloc(arg);
3613 case ACLC_RATELIMIT:
3614 rc = acl_ratelimit(arg, where, log_msgptr);
3617 case ACLC_RECIPIENTS:
3618 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3619 CUSS &recipient_data);
3622 #ifdef WITH_CONTENT_SCAN
3628 case ACLC_REMOVE_HEADER:
3629 setup_remove_header(arg);
3632 case ACLC_SENDER_DOMAINS:
3635 sdomain = Ustrrchr(sender_address, '@');
3636 sdomain = sdomain ? sdomain + 1 : US"";
3637 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3638 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3643 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3644 sender_address_cache, -1, 0, CUSS &sender_data);
3647 /* Connection variables must persist forever */
3651 int old_pool = store_pool;
3652 if ( cb->u.varname[0] == 'c'
3653 #ifndef DISABLE_DKIM
3654 || cb->u.varname[0] == 'd'
3656 #ifndef DISABLE_EVENT
3657 || event_name /* An event is being delivered */
3660 store_pool = POOL_PERM;
3661 #ifndef DISABLE_DKIM /* Overwriteable dkim result variables */
3662 if (Ustrcmp(cb->u.varname, "dkim_verify_status") == 0)
3663 dkim_verify_status = string_copy(arg);
3664 else if (Ustrcmp(cb->u.varname, "dkim_verify_reason") == 0)
3665 dkim_verify_reason = string_copy(arg);
3668 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3669 store_pool = old_pool;
3673 #ifdef WITH_CONTENT_SCAN
3676 /* Separate the regular expression and any optional parameters. */
3677 const uschar * list = arg;
3678 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3680 rc = spam(CUSS &ss);
3681 /* Modify return code based upon the existence of options. */
3682 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3683 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3684 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3691 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3693 case ACLC_SPF_GUESS:
3694 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3699 rc = acl_udpsend(arg, log_msgptr);
3702 /* If the verb is WARN, discard any user message from verification, because
3703 such messages are SMTP responses, not header additions. The latter come
3704 only from explicit "message" modifiers. However, put the user message into
3705 $acl_verify_message so it can be used in subsequent conditions or modifiers
3706 (until something changes it). */
3709 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3711 acl_verify_message = *user_msgptr;
3712 if (verb == ACL_WARN) *user_msgptr = NULL;
3716 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3717 "condition %d", cb->type);
3721 /* If a condition was negated, invert OK/FAIL. */
3723 if (!conditions[cb->type].is_modifier && cb->u.negated)
3724 if (rc == OK) rc = FAIL;
3725 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3727 if (rc != OK) break; /* Conditions loop */
3731 /* If the result is the one for which "message" and/or "log_message" are used,
3732 handle the values of these modifiers. If there isn't a log message set, we make
3733 it the same as the user message.
3735 "message" is a user message that will be included in an SMTP response. Unless
3736 it is empty, it overrides any previously set user message.
3738 "log_message" is a non-user message, and it adds to any existing non-user
3739 message that is already set.
3741 Most verbs have but a single return for which the messages are relevant, but
3742 for "discard", it's useful to have the log message both when it succeeds and
3743 when it fails. For "accept", the message is used in the OK case if there is no
3744 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3747 if (*epp && rc == OK) user_message = NULL;
3749 if ((BIT(rc) & msgcond[verb]) != 0)
3752 uschar *old_user_msgptr = *user_msgptr;
3753 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3755 /* If the verb is "warn", messages generated by conditions (verification or
3756 nested ACLs) are always discarded. This also happens for acceptance verbs
3757 when they actually do accept. Only messages specified at this level are used.
3758 However, the value of an existing message is available in $acl_verify_message
3759 during expansions. */
3761 if (verb == ACL_WARN ||
3762 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3763 *log_msgptr = *user_msgptr = NULL;
3767 acl_verify_message = old_user_msgptr;
3768 expmessage = expand_string(user_message);
3771 if (!expand_string_forcedfail)
3772 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3773 user_message, expand_string_message);
3775 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3780 acl_verify_message = old_log_msgptr;
3781 expmessage = expand_string(log_message);
3784 if (!expand_string_forcedfail)
3785 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3786 log_message, expand_string_message);
3788 else if (expmessage[0] != 0)
3790 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3791 string_sprintf("%s: %s", expmessage, *log_msgptr);
3795 /* If no log message, default it to the user message */
3797 if (!*log_msgptr) *log_msgptr = *user_msgptr;
3800 acl_verify_message = NULL;
3808 /*************************************************
3809 * Get line from a literal ACL *
3810 *************************************************/
3812 /* This function is passed to acl_read() in order to extract individual lines
3813 of a literal ACL, which we access via static pointers. We can destroy the
3814 contents because this is called only once (the compiled ACL is remembered).
3816 This code is intended to treat the data in the same way as lines in the main
3817 Exim configuration file. That is:
3819 . Leading spaces are ignored.
3821 . A \ at the end of a line is a continuation - trailing spaces after the \
3822 are permitted (this is because I don't believe in making invisible things
3823 significant). Leading spaces on the continued part of a line are ignored.
3825 . Physical lines starting (significantly) with # are totally ignored, and
3826 may appear within a sequence of backslash-continued lines.
3828 . Blank lines are ignored, but will end a sequence of continuations.
3831 Returns: a pointer to the next line
3835 static uschar *acl_text; /* Current pointer in the text */
3836 static uschar *acl_text_end; /* Points one past the terminating '0' */
3844 /* This loop handles leading blank lines and comments. */
3848 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3849 if (*acl_text == 0) return NULL; /* No more data */
3850 yield = acl_text; /* Potential data line */
3852 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3854 /* If we hit the end before a newline, we have the whole logical line. If
3855 it's a comment, there's no more data to be given. Otherwise, yield it. */
3857 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3859 /* After reaching a newline, end this loop if the physical line does not
3860 start with '#'. If it does, it's a comment, and the loop continues. */
3862 if (*yield != '#') break;
3865 /* This loop handles continuations. We know we have some real data, ending in
3866 newline. See if there is a continuation marker at the end (ignoring trailing
3867 white space). We know that *yield is not white space, so no need to test for
3868 cont > yield in the backwards scanning loop. */
3873 for (cont = acl_text - 1; isspace(*cont); cont--);
3875 /* If no continuation follows, we are done. Mark the end of the line and
3884 /* We have encountered a continuation. Skip over whitespace at the start of
3885 the next line, and indeed the whole of the next line or lines if they are
3890 while (*(++acl_text) == ' ' || *acl_text == '\t');
3891 if (*acl_text != '#') break;
3892 while (*(++acl_text) != 0 && *acl_text != '\n');
3895 /* We have the start of a continuation line. Move all the rest of the data
3896 to join onto the previous line, and then find its end. If the end is not a
3897 newline, we are done. Otherwise loop to look for another continuation. */
3899 memmove(cont, acl_text, acl_text_end - acl_text);
3900 acl_text_end -= acl_text - cont;
3902 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3903 if (*acl_text == 0) return yield;
3906 /* Control does not reach here */
3913 /*************************************************
3914 * Check access using an ACL *
3915 *************************************************/
3917 /* This function is called from address_check. It may recurse via
3918 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3919 passed as a string which is expanded. A forced failure implies no access check
3920 is required. If the result is a single word, it is taken as the name of an ACL
3921 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3922 text, complete with newlines, and parsed as such. In both cases, the ACL check
3923 is then run. This function uses an auxiliary function for acl_read() to call
3924 for reading individual lines of a literal ACL. This is acl_getline(), which
3925 appears immediately above.
3928 where where called from
3929 addr address item when called from RCPT; otherwise NULL
3930 s the input string; NULL is the same as an empty ACL => DENY
3931 user_msgptr where to put a user error (for SMTP response)
3932 log_msgptr where to put a logging message (not for SMTP response)
3934 Returns: OK access is granted
3935 DISCARD access is apparently granted...
3936 FAIL access is denied
3937 FAIL_DROP access is denied; drop the connection
3938 DEFER can't tell at the moment
3943 acl_check_internal(int where, address_item *addr, uschar *s,
3944 uschar **user_msgptr, uschar **log_msgptr)
3947 acl_block *acl = NULL;
3948 uschar *acl_name = US"inline ACL";
3951 /* Catch configuration loops */
3955 *log_msgptr = US"ACL nested too deep: possible loop";
3961 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3965 /* At top level, we expand the incoming string. At lower levels, it has already
3966 been expanded as part of condition processing. */
3970 if (!(ss = expand_string(s)))
3972 if (expand_string_forcedfail) return OK;
3973 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3974 expand_string_message);
3980 while (isspace(*ss)) ss++;
3982 /* If we can't find a named ACL, the default is to parse it as an inline one.
3983 (Unless it begins with a slash; non-existent files give rise to an error.) */
3987 /* Handle the case of a string that does not contain any spaces. Look for a
3988 named ACL among those read from the configuration, or a previously read file.
3989 It is possible that the pointer to the ACL is NULL if the configuration
3990 contains a name with no data. If not found, and the text begins with '/',
3991 read an ACL from a file, and save it so it can be re-used. */
3993 if (Ustrchr(ss, ' ') == NULL)
3995 tree_node *t = tree_search(acl_anchor, ss);
3998 acl = (acl_block *)(t->data.ptr);
4001 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
4004 acl_name = string_sprintf("ACL \"%s\"", ss);
4005 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
4008 else if (*ss == '/')
4010 struct stat statbuf;
4011 fd = Uopen(ss, O_RDONLY, 0);
4014 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
4019 if (fstat(fd, &statbuf) != 0)
4021 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
4026 acl_text = store_get(statbuf.st_size + 1);
4027 acl_text_end = acl_text + statbuf.st_size + 1;
4029 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
4031 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
4032 ss, strerror(errno));
4035 acl_text[statbuf.st_size] = 0;
4038 acl_name = string_sprintf("ACL \"%s\"", ss);
4039 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
4043 /* Parse an ACL that is still in text form. If it came from a file, remember it
4044 in the ACL tree, having read it into the POOL_PERM store pool so that it
4045 persists between multiple messages. */
4049 int old_pool = store_pool;
4050 if (fd >= 0) store_pool = POOL_PERM;
4051 acl = acl_read(acl_getline, log_msgptr);
4052 store_pool = old_pool;
4053 if (acl == NULL && *log_msgptr != NULL) return ERROR;
4056 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
4057 Ustrcpy(t->name, ss);
4059 (void)tree_insertnode(&acl_anchor, t);
4063 /* Now we have an ACL to use. It's possible it may be NULL. */
4068 int basic_errno = 0;
4069 BOOL endpass_seen = FALSE;
4070 BOOL acl_quit_check = acl_level == 0
4071 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4073 *log_msgptr = *user_msgptr = NULL;
4074 acl_temp_details = FALSE;
4076 HDEBUG(D_acl) debug_printf_indent("processing \"%s\"\n", verbs[acl->verb]);
4078 /* Clear out any search error message from a previous check before testing
4081 search_error_message = NULL;
4082 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4083 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4085 /* Handle special returns: DEFER causes a return except on a WARN verb;
4086 ERROR always causes a return. */
4091 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
4092 if (basic_errno != ERRNO_CALLOUTDEFER)
4094 if (search_error_message != NULL && *search_error_message != 0)
4095 *log_msgptr = search_error_message;
4096 if (smtp_return_error_details) acl_temp_details = TRUE;
4100 acl_temp_details = TRUE;
4102 if (acl->verb != ACL_WARN) return DEFER;
4105 default: /* Paranoia */
4107 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
4111 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4112 verbs[acl->verb], acl_name);
4116 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
4119 /* DISCARD and DROP can happen only from a nested ACL condition, and
4120 DISCARD can happen only for an "accept" or "discard" verb. */
4123 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4124 verbs[acl->verb], acl_name);
4128 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4129 verbs[acl->verb], acl_name);
4133 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4134 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4135 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4140 if (cond == OK || cond == DISCARD)
4142 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4147 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4155 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4156 if (acl_quit_check) goto badquit;
4157 acl_temp_details = TRUE;
4165 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4166 if (acl_quit_check) goto badquit;
4172 if (cond == OK || cond == DISCARD)
4174 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4175 if (acl_quit_check) goto badquit;
4180 HDEBUG(D_acl) debug_printf_indent("discard: endpass encountered - denying access\n");
4188 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4189 if (acl_quit_check) goto badquit;
4197 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4198 if (acl_quit_check) goto badquit;
4205 acl_warn(where, *user_msgptr, *log_msgptr);
4206 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4207 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4208 "condition test deferred%s%s", host_and_ident(TRUE),
4209 (*log_msgptr == NULL)? US"" : US": ",
4210 (*log_msgptr == NULL)? US"" : *log_msgptr);
4211 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4215 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4220 /* Pass to the next ACL item */
4225 /* We have reached the end of the ACL. This is an implicit DENY. */
4227 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4231 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4232 "('%s' verb used incorrectly)", verbs[acl->verb]);
4239 /* Same args as acl_check_internal() above, but the string s is
4240 the name of an ACL followed optionally by up to 9 space-separated arguments.
4241 The name and args are separately expanded. Args go into $acl_arg globals. */
4243 acl_check_wargs(int where, address_item *addr, const uschar *s,
4244 uschar **user_msgptr, uschar **log_msgptr)
4247 uschar * tmp_arg[9]; /* must match acl_arg[] */
4248 uschar * sav_arg[9]; /* must match acl_arg[] */
4254 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4257 for (i = 0; i < 9; i++)
4259 while (*s && isspace(*s)) s++;
4261 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4268 sav_narg = acl_narg;
4270 for (i = 0; i < acl_narg; i++)
4272 sav_arg[i] = acl_arg[i];
4273 acl_arg[i] = tmp_arg[i];
4277 sav_arg[i] = acl_arg[i];
4278 acl_arg[i++] = NULL;
4282 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4285 acl_narg = sav_narg;
4286 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4290 if (expand_string_forcedfail) return ERROR;
4291 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4292 tmp, expand_string_message);
4293 return search_find_defer?DEFER:ERROR;
4298 /*************************************************
4299 * Check access using an ACL *
4300 *************************************************/
4302 /* Alternate interface for ACL, used by expansions */
4304 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4307 address_item *addr = NULL;
4310 *user_msgptr = *log_msgptr = NULL;
4311 sender_verified_failed = NULL;
4312 ratelimiters_cmd = NULL;
4313 log_reject_target = LOG_MAIN|LOG_REJECT;
4315 if (where == ACL_WHERE_RCPT)
4317 adb = address_defaults;
4319 addr->address = expand_string(US"$local_part@$domain");
4320 addr->domain = deliver_domain;
4321 addr->local_part = deliver_localpart;
4322 addr->cc_local_part = deliver_localpart;
4323 addr->lc_local_part = deliver_localpart;
4327 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4334 /* This is the external interface for ACL checks. It sets up an address and the
4335 expansions for $domain and $local_part when called after RCPT, then calls
4336 acl_check_internal() to do the actual work.
4339 where ACL_WHERE_xxxx indicating where called from
4340 recipient RCPT address for RCPT check, else NULL
4341 s the input string; NULL is the same as an empty ACL => DENY
4342 user_msgptr where to put a user error (for SMTP response)
4343 log_msgptr where to put a logging message (not for SMTP response)
4345 Returns: OK access is granted by an ACCEPT verb
4346 DISCARD access is granted by a DISCARD verb
4347 FAIL access is denied
4348 FAIL_DROP access is denied; drop the connection
4349 DEFER can't tell at the moment
4352 int acl_where = ACL_WHERE_UNKNOWN;
4355 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4356 uschar **log_msgptr)
4360 address_item *addr = NULL;
4362 *user_msgptr = *log_msgptr = NULL;
4363 sender_verified_failed = NULL;
4364 ratelimiters_cmd = NULL;
4365 log_reject_target = LOG_MAIN|LOG_REJECT;
4367 #ifndef DISABLE_PRDR
4368 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4370 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4373 adb = address_defaults;
4375 addr->address = recipient;
4376 if (deliver_split_address(addr) == DEFER)
4378 *log_msgptr = US"defer in percent_hack_domains check";
4382 if ((addr->prop.utf8_msg = message_smtputf8))
4384 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4385 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4388 deliver_domain = addr->domain;
4389 deliver_localpart = addr->local_part;
4394 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4396 acl_where = ACL_WHERE_UNKNOWN;
4398 /* Cutthrough - if requested,
4399 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4400 and rcpt acl returned accept,
4401 and first recipient (cancel on any subsequents)
4402 open one now and run it up to RCPT acceptance.
4403 A failed verify should cancel cutthrough request,
4404 and will pass the fail to the originator.
4405 Initial implementation: dual-write to spool.
4406 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4408 Cease cutthrough copy on rxd final dot; do not send one.
4410 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4412 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4413 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4414 If temp-reject, close the conn (and keep the spooled copy).
4415 If conn-failure, no action (and keep the spooled copy).
4419 case ACL_WHERE_RCPT:
4420 #ifndef DISABLE_PRDR
4421 case ACL_WHERE_PRDR:
4424 if (host_checking_callout) /* -bhc mode */
4425 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4428 && cutthrough.delivery
4429 && rcpt_count > cutthrough.nrcpt
4432 if ((rc = open_cutthrough_connection(addr)) == DEFER)
4433 if (cutthrough.defer_pass)
4435 uschar * s = addr->message;
4436 /* Horrid kludge to recover target's SMTP message */
4438 do --s; while (!isdigit(*s));
4439 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4440 acl_temp_details = TRUE;
4444 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4448 else HDEBUG(D_acl) if (cutthrough.delivery)
4449 if (rcpt_count <= cutthrough.nrcpt)
4450 debug_printf_indent("ignore cutthrough request; nonfirst message\n");
4452 debug_printf_indent("ignore cutthrough request; ACL did not accept\n");
4455 case ACL_WHERE_PREDATA:
4457 cutthrough_predata();
4459 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4462 case ACL_WHERE_QUIT:
4463 case ACL_WHERE_NOTQUIT:
4464 /* Drop cutthrough conns, and drop heldopen verify conns if
4465 the previous was not DATA */
4467 uschar prev = smtp_connection_had[smtp_ch_index-2];
4468 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4470 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4478 deliver_domain = deliver_localpart = deliver_address_data =
4479 sender_address_data = NULL;
4481 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4482 ACL, which is really in the middle of an SMTP command. */
4486 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4488 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4489 "ACL", acl_wherenames[where]);
4495 /* A DROP response is not permitted from MAILAUTH */
4497 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4499 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4500 "ACL", acl_wherenames[where]);
4504 /* Before giving a response, take a look at the length of any user message, and
4505 split it up into multiple lines if possible. */
4507 *user_msgptr = string_split_message(*user_msgptr);
4508 if (fake_response != OK)
4509 fake_response_text = string_split_message(fake_response_text);
4515 /*************************************************
4516 * Create ACL variable *
4517 *************************************************/
4519 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4520 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4523 name pointer to the variable's name, starting with c or m
4525 Returns the pointer to variable's tree node
4529 acl_var_create(uschar * name)
4531 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4532 if (!(node = tree_search(*root, name)))
4534 node = store_get(sizeof(tree_node) + Ustrlen(name));
4535 Ustrcpy(node->name, name);
4536 (void)tree_insertnode(root, node);
4538 node->data.ptr = NULL;
4544 /*************************************************
4545 * Write an ACL variable in spool format *
4546 *************************************************/
4548 /* This function is used as a callback for tree_walk when writing variables to
4549 the spool file. To retain spool file compatibility, what is written is -aclc or
4550 -aclm followed by the rest of the name and the data length, space separated,
4551 then the value itself, starting on a new line, and terminated by an additional
4552 newline. When we had only numbered ACL variables, the first line might look
4553 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4557 name of the variable
4558 value of the variable
4559 ctx FILE pointer (as a void pointer)
4565 acl_var_write(uschar *name, uschar *value, void *ctx)
4567 FILE *f = (FILE *)ctx;
4568 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);