1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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] = (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP),
41 [ACL_DEFER] = (1<<OK),
43 [ACL_DISCARD] = (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP),
45 [ACL_REQUIRE] = (1<<FAIL) | (1<<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
105 #ifdef EXPERIMENTAL_SPF
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 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
141 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
145 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
147 (1<<ACL_WHERE_NOTSMTP_START)),
150 [ACLC_AUTHENTICATED] = { US"authenticated", FALSE, FALSE,
151 (1<<ACL_WHERE_NOTSMTP)|
152 (1<<ACL_WHERE_NOTSMTP_START)|
153 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
155 #ifdef EXPERIMENTAL_BRIGHTMAIL
156 [ACLC_BMI_OPTIN] = { US"bmi_optin", TRUE, TRUE,
158 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
159 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
160 # ifndef DISABLE_PRDR
163 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
164 (1<<ACL_WHERE_MAILAUTH)|
165 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
166 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
167 (1<<ACL_WHERE_NOTSMTP_START),
170 [ACLC_CONDITION] = { US"condition", TRUE, FALSE, 0 },
171 [ACLC_CONTINUE] = { US"continue", TRUE, TRUE, 0 },
173 /* Certain types of control are always allowed, so we let it through
174 always and check in the control processing itself. */
175 [ACLC_CONTROL] = { US"control", TRUE, TRUE, 0 },
177 #ifdef EXPERIMENTAL_DCC
178 [ACLC_DCC] = { US"dcc", TRUE, FALSE,
180 ~((1<<ACL_WHERE_DATA)|
181 # ifndef DISABLE_PRDR
184 (1<<ACL_WHERE_NOTSMTP)),
187 #ifdef WITH_CONTENT_SCAN
188 [ACLC_DECODE] = { US"decode", TRUE, FALSE, (unsigned int) ~(1<<ACL_WHERE_MIME) },
191 [ACLC_DELAY] = { US"delay", TRUE, TRUE, (1<<ACL_WHERE_NOTQUIT) },
193 [ACLC_DKIM_SIGNER] = { US"dkim_signers", TRUE, FALSE, (unsigned int) ~(1<<ACL_WHERE_DKIM) },
194 [ACLC_DKIM_STATUS] = { US"dkim_status", TRUE, FALSE, (unsigned int) ~(1<<ACL_WHERE_DKIM) },
196 #ifdef EXPERIMENTAL_DMARC
197 [ACLC_DMARC_STATUS] = { US"dmarc_status", TRUE, FALSE, (unsigned int) ~(1<<ACL_WHERE_DATA) },
200 /* Explicit key lookups can be made in non-smtp ACLs so pass
201 always and check in the verify processing itself. */
202 [ACLC_DNSLISTS] = { US"dnslists", TRUE, FALSE, 0 },
204 [ACLC_DOMAINS] = { US"domains", FALSE, FALSE,
206 ~((1<<ACL_WHERE_RCPT)
213 [ACLC_ENCRYPTED] = { US"encrypted", FALSE, FALSE,
214 (1<<ACL_WHERE_NOTSMTP)|
215 (1<<ACL_WHERE_CONNECT)|
216 (1<<ACL_WHERE_NOTSMTP_START)|
220 [ACLC_ENDPASS] = { US"endpass", TRUE, TRUE, 0 },
222 [ACLC_HOSTS] = { US"hosts", FALSE, FALSE,
223 (1<<ACL_WHERE_NOTSMTP)|
224 (1<<ACL_WHERE_NOTSMTP_START),
226 [ACLC_LOCAL_PARTS] = { US"local_parts", FALSE, FALSE,
228 ~((1<<ACL_WHERE_RCPT)
236 [ACLC_LOG_MESSAGE] = { US"log_message", TRUE, TRUE, 0 },
237 [ACLC_LOG_REJECT_TARGET] = { US"log_reject_target", TRUE, TRUE, 0 },
238 [ACLC_LOGWRITE] = { US"logwrite", TRUE, TRUE, 0 },
240 #ifdef WITH_CONTENT_SCAN
241 [ACLC_MALWARE] = { US"malware", TRUE, FALSE,
243 ~((1<<ACL_WHERE_DATA)|
244 # ifndef DISABLE_PRDR
247 (1<<ACL_WHERE_NOTSMTP)),
251 [ACLC_MESSAGE] = { US"message", TRUE, TRUE, 0 },
252 #ifdef WITH_CONTENT_SCAN
253 [ACLC_MIME_REGEX] = { US"mime_regex", TRUE, FALSE, (unsigned int) ~(1<<ACL_WHERE_MIME) },
256 [ACLC_QUEUE] = { US"queue", TRUE, TRUE,
257 (1<<ACL_WHERE_NOTSMTP)|
264 [ACLC_RATELIMIT] = { US"ratelimit", TRUE, FALSE, 0 },
265 [ACLC_RECIPIENTS] = { US"recipients", FALSE, FALSE, (unsigned int) ~(1<<ACL_WHERE_RCPT) },
267 #ifdef WITH_CONTENT_SCAN
268 [ACLC_REGEX] = { US"regex", TRUE, FALSE,
270 ~((1<<ACL_WHERE_DATA)|
271 # ifndef DISABLE_PRDR
274 (1<<ACL_WHERE_NOTSMTP)|
275 (1<<ACL_WHERE_MIME)),
279 [ACLC_REMOVE_HEADER] = { US"remove_header", TRUE, TRUE,
281 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
282 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
286 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
287 (1<<ACL_WHERE_NOTSMTP_START)),
289 [ACLC_SENDER_DOMAINS] = { US"sender_domains", FALSE, FALSE,
290 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|
292 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
293 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
294 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
296 [ACLC_SENDERS] = { US"senders", FALSE, FALSE,
297 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|
299 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
300 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
301 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
304 [ACLC_SET] = { US"set", TRUE, TRUE, 0 },
306 #ifdef WITH_CONTENT_SCAN
307 [ACLC_SPAM] = { US"spam", TRUE, FALSE,
308 (unsigned int) ~((1<<ACL_WHERE_DATA)|
309 # ifndef DISABLE_PRDR
312 (1<<ACL_WHERE_NOTSMTP)),
315 #ifdef EXPERIMENTAL_SPF
316 [ACLC_SPF] = { US"spf", TRUE, FALSE,
317 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|
319 (1<<ACL_WHERE_MAILAUTH)|
320 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
321 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
322 (1<<ACL_WHERE_NOTSMTP)|
323 (1<<ACL_WHERE_NOTSMTP_START),
325 [ACLC_SPF_GUESS] = { US"spf_guess", TRUE, FALSE,
326 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)|
328 (1<<ACL_WHERE_MAILAUTH)|
329 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
330 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
331 (1<<ACL_WHERE_NOTSMTP)|
332 (1<<ACL_WHERE_NOTSMTP_START),
335 [ACLC_UDPSEND] = { US"udpsend", TRUE, TRUE, 0 },
337 /* Certain types of verify are always allowed, so we let it through
338 always and check in the verify function itself */
339 [ACLC_VERIFY] = { US"verify", TRUE, FALSE, 0 },
344 /* Return values from decode_control(); used as index so keep in step
345 with the controls_list table that follows! */
348 CONTROL_AUTH_UNADVERTISED,
349 #ifdef EXPERIMENTAL_BRIGHTMAIL
352 CONTROL_CASEFUL_LOCAL_PART,
353 CONTROL_CASELOWER_LOCAL_PART,
354 CONTROL_CUTTHROUGH_DELIVERY,
359 #ifdef EXPERIMENTAL_DMARC
360 CONTROL_DMARC_VERIFY,
361 CONTROL_DMARC_FORENSIC,
364 CONTROL_ENFORCE_SYNC,
365 CONTROL_ERROR, /* pseudo-value for decode errors */
370 CONTROL_NO_CALLOUT_FLUSH,
371 CONTROL_NO_DELAY_FLUSH,
372 CONTROL_NO_ENFORCE_SYNC,
373 #ifdef WITH_CONTENT_SCAN
374 CONTROL_NO_MBOX_UNSPOOL,
376 CONTROL_NO_MULTILINE,
377 CONTROL_NO_PIPELINING,
381 CONTROL_SUPPRESS_LOCAL_FIXUPS,
383 CONTROL_UTF8_DOWNCONVERT,
389 /* Structure listing various control arguments, with their characteristics.
390 For each control, there's a bitmap of dis-allowed times. For some, it is easier
391 to specify the negation of a small number of allowed times. */
393 typedef struct control_def {
395 BOOL has_option; /* Has /option(s) following */
396 unsigned forbids; /* bitmap of dis-allowed times */
399 static control_def controls_list[] = {
400 /* name has_option forbids */
401 [CONTROL_AUTH_UNADVERTISED] =
402 { US"allow_auth_unadvertised", FALSE,
404 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO))
406 #ifdef EXPERIMENTAL_BRIGHTMAIL
408 { US"bmi_run", FALSE, 0 },
410 [CONTROL_CASEFUL_LOCAL_PART] =
411 { US"caseful_local_part", FALSE, (unsigned) ~(1<<ACL_WHERE_RCPT) },
412 [CONTROL_CASELOWER_LOCAL_PART] =
413 { US"caselower_local_part", FALSE, (unsigned) ~(1<<ACL_WHERE_RCPT) },
414 [CONTROL_CUTTHROUGH_DELIVERY] =
415 { US"cutthrough_delivery", TRUE, 0 },
417 { US"debug", TRUE, 0 },
420 [CONTROL_DKIM_VERIFY] =
421 { US"dkim_disable_verify", FALSE,
422 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|
423 # ifndef DISABLE_PRDR
426 (1<<ACL_WHERE_NOTSMTP_START)
430 #ifdef EXPERIMENTAL_DMARC
431 [CONTROL_DMARC_VERIFY] =
432 { US"dmarc_disable_verify", FALSE,
433 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
435 [CONTROL_DMARC_FORENSIC] =
436 { US"dmarc_enable_forensic", FALSE,
437 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
443 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)|(1<<ACL_WHERE_NOTQUIT)
445 [CONTROL_ENFORCE_SYNC] =
446 { US"enforce_sync", FALSE,
447 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
450 /* Pseudo-value for decode errors */
452 { US"error", FALSE, 0 },
454 [CONTROL_FAKEDEFER] =
455 { US"fakedefer", TRUE,
457 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
458 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
464 [CONTROL_FAKEREJECT] =
465 { US"fakereject", TRUE,
467 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
468 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
477 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
478 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
479 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
480 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME))
483 [CONTROL_NO_CALLOUT_FLUSH] =
484 { US"no_callout_flush", FALSE,
485 (1<<ACL_WHERE_NOTSMTP)| (1<<ACL_WHERE_NOTSMTP_START)
487 [CONTROL_NO_DELAY_FLUSH] =
488 { US"no_delay_flush", FALSE,
489 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
492 [CONTROL_NO_ENFORCE_SYNC] =
493 { US"no_enforce_sync", FALSE,
494 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
496 #ifdef WITH_CONTENT_SCAN
497 [CONTROL_NO_MBOX_UNSPOOL] =
498 { US"no_mbox_unspool", FALSE,
500 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
501 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
502 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
506 [CONTROL_NO_MULTILINE] =
507 { US"no_multiline_responses", FALSE,
508 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
510 [CONTROL_NO_PIPELINING] =
511 { US"no_pipelining", FALSE,
512 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_NOTSMTP_START)
515 [CONTROL_QUEUE_ONLY] =
516 { US"queue_only", FALSE,
518 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|
519 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
520 // (1<<ACL_WHERE_PRDR)| /* Not allow one user to freeze for all */
521 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME))
523 [CONTROL_SUBMISSION] =
524 { US"submission", TRUE,
526 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA))
528 [CONTROL_SUPPRESS_LOCAL_FIXUPS] =
529 { US"suppress_local_fixups", FALSE,
531 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)|(1<<ACL_WHERE_PREDATA)|
532 (1<<ACL_WHERE_NOTSMTP_START))
535 [CONTROL_UTF8_DOWNCONVERT] =
536 { US"utf8_downconvert", TRUE, 0 }
540 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
541 caches its result in a tree to avoid repeated DNS queries. The result is an
542 integer code which is used as an index into the following tables of
543 explanatory strings and verification return codes. */
545 static tree_node *csa_cache = NULL;
547 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
548 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
550 /* The acl_verify_csa() return code is translated into an acl_verify() return
551 code using the following table. It is OK unless the client is definitely not
552 authorized. This is because CSA is supposed to be optional for sending sites,
553 so recipients should not be too strict about checking it - especially because
554 DNS problems are quite likely to occur. It's possible to use $csa_status in
555 further ACL conditions to distinguish ok, unknown, and defer if required, but
556 the aim is to make the usual configuration simple. */
558 static int csa_return_code[] = {
561 [CSA_DEFER_SRV] = OK,
562 [CSA_DEFER_ADDR] = OK,
563 [CSA_FAIL_EXPLICIT] = FAIL,
564 [CSA_FAIL_DOMAIN] = FAIL,
565 [CSA_FAIL_NOADDR] = FAIL,
566 [CSA_FAIL_MISMATCH] = FAIL
569 static uschar *csa_status_string[] = {
570 [CSA_UNKNOWN] = US"unknown",
572 [CSA_DEFER_SRV] = US"defer",
573 [CSA_DEFER_ADDR] = US"defer",
574 [CSA_FAIL_EXPLICIT] = US"fail",
575 [CSA_FAIL_DOMAIN] = US"fail",
576 [CSA_FAIL_NOADDR] = US"fail",
577 [CSA_FAIL_MISMATCH] = US"fail"
580 static uschar *csa_reason_string[] = {
581 [CSA_UNKNOWN] = US"unknown",
583 [CSA_DEFER_SRV] = US"deferred (SRV lookup failed)",
584 [CSA_DEFER_ADDR] = US"deferred (target address lookup failed)",
585 [CSA_FAIL_EXPLICIT] = US"failed (explicit authorization required)",
586 [CSA_FAIL_DOMAIN] = US"failed (host name not authorized)",
587 [CSA_FAIL_NOADDR] = US"failed (no authorized addresses)",
588 [CSA_FAIL_MISMATCH] = US"failed (client address mismatch)"
591 /* Options for the ratelimit condition. Note that there are two variants of
592 the per_rcpt option, depending on the ACL that is used to measure the rate.
593 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
594 so the two variants must have the same internal representation as well as
595 the same configuration string. */
598 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
599 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
602 #define RATE_SET(var,new) \
603 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
605 static uschar *ratelimit_option_string[] = {
606 [RATE_PER_WHAT] = US"?",
607 [RATE_PER_CLASH] = US"!",
608 [RATE_PER_ADDR] = US"per_addr",
609 [RATE_PER_BYTE] = US"per_byte",
610 [RATE_PER_CMD] = US"per_cmd",
611 [RATE_PER_CONN] = US"per_conn",
612 [RATE_PER_MAIL] = US"per_mail",
613 [RATE_PER_RCPT] = US"per_rcpt",
614 [RATE_PER_ALLRCPTS] = US"per_rcpt"
617 /* Enable recursion between acl_check_internal() and acl_check_condition() */
619 static int acl_check_wargs(int, address_item *, const uschar *, uschar **,
623 /*************************************************
624 * Find control in list *
625 *************************************************/
627 /* The lists are always in order, so binary chop can be used.
630 name the control name to search for
631 ol the first entry in the control list
632 last one more than the offset of the last entry in the control list
634 Returns: index of a control entry, or -1 if not found
638 find_control(const uschar * name, control_def * ol, int last)
643 int middle = (first + last)/2;
644 uschar * s = ol[middle].name;
645 int c = Ustrncmp(name, s, Ustrlen(s));
646 if (c == 0) return middle;
647 else if (c > 0) first = middle + 1;
655 /*************************************************
656 * Pick out condition from list *
657 *************************************************/
659 /* Use a binary chop method
663 list list of conditions
666 Returns: offset in list, or -1 if not found
670 acl_checkcondition(uschar * name, condition_def * list, int end)
675 int mid = (start + end)/2;
676 int c = Ustrcmp(name, list[mid].name);
677 if (c == 0) return mid;
678 if (c < 0) end = mid;
679 else start = mid + 1;
685 /*************************************************
686 * Pick out name from list *
687 *************************************************/
689 /* Use a binary chop method
696 Returns: offset in list, or -1 if not found
700 acl_checkname(uschar *name, uschar **list, int end)
706 int mid = (start + end)/2;
707 int c = Ustrcmp(name, list[mid]);
708 if (c == 0) return mid;
709 if (c < 0) end = mid; else start = mid + 1;
716 /*************************************************
717 * Read and parse one ACL *
718 *************************************************/
720 /* This function is called both from readconf in order to parse the ACLs in the
721 configuration file, and also when an ACL is encountered dynamically (e.g. as
722 the result of an expansion). It is given a function to call in order to
723 retrieve the lines of the ACL. This function handles skipping comments and
724 blank lines (where relevant).
727 func function to get next line of ACL
728 error where to put an error message
730 Returns: pointer to ACL, or NULL
731 NULL can be legal (empty ACL); in this case error will be NULL
735 acl_read(uschar *(*func)(void), uschar **error)
737 acl_block *yield = NULL;
738 acl_block **lastp = &yield;
739 acl_block *this = NULL;
740 acl_condition_block *cond;
741 acl_condition_block **condp = NULL;
746 while ((s = (*func)()) != NULL)
749 BOOL negated = FALSE;
750 uschar *saveline = s;
753 /* Conditions (but not verbs) are allowed to be negated by an initial
756 while (isspace(*s)) s++;
763 /* Read the name of a verb or a condition, or the start of a new ACL, which
764 can be started by a name, or by a macro definition. */
766 s = readconf_readname(name, sizeof(name), s);
767 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
769 /* If a verb is unrecognized, it may be another condition or modifier that
770 continues the previous verb. */
772 if ((v = acl_checkname(name, verbs, nelem(verbs))) < 0)
776 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
788 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
791 this = store_get(sizeof(acl_block));
793 lastp = &(this->next);
796 this->condition = NULL;
797 condp = &(this->condition);
798 if (*s == 0) continue; /* No condition on this line */
804 s = readconf_readname(name, sizeof(name), s); /* Condition name */
807 /* Handle a condition or modifier. */
809 if ((c = acl_checkcondition(name, conditions, nelem(conditions))) < 0)
811 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
816 /* The modifiers may not be negated */
818 if (negated && conditions[c].is_modifier)
820 *error = string_sprintf("ACL error: negation is not allowed with "
821 "\"%s\"", conditions[c].name);
825 /* ENDPASS may occur only with ACCEPT or DISCARD. */
827 if (c == ACLC_ENDPASS &&
828 this->verb != ACL_ACCEPT &&
829 this->verb != ACL_DISCARD)
831 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
832 conditions[c].name, verbs[this->verb]);
836 cond = store_get(sizeof(acl_condition_block));
839 cond->u.negated = negated;
842 condp = &(cond->next);
844 /* The "set" modifier is different in that its argument is "name=value"
845 rather than just a value, and we can check the validity of the name, which
846 gives us a variable name to insert into the data block. The original ACL
847 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
848 extended to 20 of each type, but after that people successfully argued for
849 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
850 After that, we allow alphanumerics and underscores, but the first character
851 after c or m must be a digit or an underscore. This retains backwards
858 if (Ustrncmp(s, "acl_c", 5) != 0 &&
859 Ustrncmp(s, "acl_m", 5) != 0)
861 *error = string_sprintf("invalid variable name after \"set\" in ACL "
862 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
867 if (!isdigit(*endptr) && *endptr != '_')
869 *error = string_sprintf("invalid variable name after \"set\" in ACL "
870 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
875 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
877 if (!isalnum(*endptr) && *endptr != '_')
879 *error = string_sprintf("invalid character \"%c\" in variable name "
880 "in ACL modifier \"set %s\"", *endptr, s);
886 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
888 while (isspace(*s)) s++;
891 /* For "set", we are now positioned for the data. For the others, only
892 "endpass" has no data */
894 if (c != ACLC_ENDPASS)
898 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
899 conditions[c].is_modifier ? US"modifier" : US"condition");
902 while (isspace(*s)) s++;
903 cond->arg = string_copy(s);
912 /*************************************************
913 * Set up added header line(s) *
914 *************************************************/
916 /* This function is called by the add_header modifier, and also from acl_warn()
917 to implement the now-deprecated way of adding header lines using "message" on a
918 "warn" verb. The argument is treated as a sequence of header lines which are
919 added to a chain, provided there isn't an identical one already there.
921 Argument: string of header lines
926 setup_header(const uschar *hstring)
929 int hlen = Ustrlen(hstring);
931 /* Ignore any leading newlines */
932 while (*hstring == '\n') hstring++, hlen--;
934 /* An empty string does nothing; ensure exactly one final newline. */
935 if (hlen <= 0) return;
936 if (hstring[--hlen] != '\n') /* no newline */
937 q = string_sprintf("%s\n", hstring);
938 else if (hstring[hlen-1] == '\n') /* double newline */
940 uschar * s = string_copy(hstring);
941 while(s[--hlen] == '\n')
948 /* Loop for multiple header lines, taking care about continuations */
950 for (p = q; *p != 0; )
954 int newtype = htype_add_bot;
955 header_line **hptr = &acl_added_headers;
957 /* Find next header line within the string */
961 q = Ustrchr(q, '\n'); /* we know there was a newline */
962 if (*(++q) != ' ' && *q != '\t') break;
965 /* If the line starts with a colon, interpret the instruction for where to
966 add it. This temporarily sets up a new type. */
970 if (strncmpic(p, US":after_received:", 16) == 0)
972 newtype = htype_add_rec;
975 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
977 newtype = htype_add_rfc;
980 else if (strncmpic(p, US":at_start:", 10) == 0)
982 newtype = htype_add_top;
985 else if (strncmpic(p, US":at_end:", 8) == 0)
987 newtype = htype_add_bot;
990 while (*p == ' ' || *p == '\t') p++;
993 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
994 to the front of it. */
996 for (s = p; s < q - 1; s++)
998 if (*s == ':' || !isgraph(*s)) break;
1001 hdr = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
1002 hlen = Ustrlen(hdr);
1004 /* See if this line has already been added */
1006 while (*hptr != NULL)
1008 if (Ustrncmp((*hptr)->text, hdr, hlen) == 0) break;
1009 hptr = &((*hptr)->next);
1012 /* Add if not previously present */
1016 header_line *h = store_get(sizeof(header_line));
1025 /* Advance for next header line within the string */
1033 /*************************************************
1034 * List the added header lines *
1035 *************************************************/
1039 uschar * ret = NULL;
1042 header_line * h = acl_added_headers;
1046 if (!h) return NULL;
1051 while ((cp = Ustrchr(s, '\n')) != NULL)
1053 if (cp[1] == '\0') break;
1055 /* contains embedded newline; needs doubling */
1056 ret = string_catn(ret, &size, &ptr, s, cp-s+1);
1057 ret = string_catn(ret, &size, &ptr, US"\n", 1);
1060 /* last bit of header */
1062 ret = string_catn(ret, &size, &ptr, s, cp-s+1); /* newline-sep list */
1064 while((h = h->next));
1066 ret[ptr-1] = '\0'; /* overwrite last newline */
1071 /*************************************************
1072 * Set up removed header line(s) *
1073 *************************************************/
1075 /* This function is called by the remove_header modifier. The argument is
1076 treated as a sequence of header names which are added to a colon separated
1077 list, provided there isn't an identical one already there.
1079 Argument: string of header names
1084 setup_remove_header(const uschar *hnames)
1087 acl_removed_headers = acl_removed_headers
1088 ? string_sprintf("%s : %s", acl_removed_headers, hnames)
1089 : string_copy(hnames);
1094 /*************************************************
1096 *************************************************/
1098 /* This function is called when a WARN verb's conditions are true. It adds to
1099 the message's headers, and/or writes information to the log. In each case, this
1100 only happens once (per message for headers, per connection for log).
1102 ** NOTE: The header adding action using the "message" setting is historic, and
1103 its use is now deprecated. The new add_header modifier should be used instead.
1106 where ACL_WHERE_xxxx indicating which ACL this is
1107 user_message message for adding to headers
1108 log_message message for logging, if different
1114 acl_warn(int where, uschar *user_message, uschar *log_message)
1116 if (log_message != NULL && log_message != user_message)
1119 string_item *logged;
1121 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1122 string_printing(log_message));
1124 /* If a sender verification has failed, and the log message is "sender verify
1125 failed", add the failure message. */
1127 if (sender_verified_failed != NULL &&
1128 sender_verified_failed->message != NULL &&
1129 strcmpic(log_message, US"sender verify failed") == 0)
1130 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1132 /* Search previously logged warnings. They are kept in malloc
1133 store so they can be freed at the start of a new message. */
1135 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1136 if (Ustrcmp(logged->text, text) == 0) break;
1140 int length = Ustrlen(text) + 1;
1141 log_write(0, LOG_MAIN, "%s", text);
1142 logged = store_malloc(sizeof(string_item) + length);
1143 logged->text = US logged + sizeof(string_item);
1144 memcpy(logged->text, text, length);
1145 logged->next = acl_warn_logged;
1146 acl_warn_logged = logged;
1150 /* If there's no user message, we are done. */
1152 if (user_message == NULL) return;
1154 /* If this isn't a message ACL, we can't do anything with a user message.
1157 if (where > ACL_WHERE_NOTSMTP)
1159 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1160 "found in a non-message (%s) ACL: cannot specify header lines here: "
1161 "message ignored", acl_wherenames[where]);
1165 /* The code for setting up header lines is now abstracted into a separate
1166 function so that it can be used for the add_header modifier as well. */
1168 setup_header(user_message);
1173 /*************************************************
1174 * Verify and check reverse DNS *
1175 *************************************************/
1177 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1178 address if this has not yet been done. The host_name_lookup() function checks
1179 that one of these names resolves to an address list that contains the client IP
1180 address, so we don't actually have to do the check here.
1183 user_msgptr pointer for user message
1184 log_msgptr pointer for log message
1186 Returns: OK verification condition succeeded
1187 FAIL verification failed
1188 DEFER there was a problem verifying
1192 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1196 user_msgptr = user_msgptr; /* stop compiler warning */
1198 /* Previous success */
1200 if (sender_host_name != NULL) return OK;
1202 /* Previous failure */
1204 if (host_lookup_failed)
1206 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1210 /* Need to do a lookup */
1213 debug_printf_indent("looking up host name to force name/address consistency check\n");
1215 if ((rc = host_name_lookup()) != OK)
1217 *log_msgptr = (rc == DEFER)?
1218 US"host lookup deferred for reverse lookup check"
1220 string_sprintf("host lookup failed for reverse lookup check%s",
1222 return rc; /* DEFER or FAIL */
1225 host_build_sender_fullhost();
1231 /*************************************************
1232 * Check client IP address matches CSA target *
1233 *************************************************/
1235 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1236 response for address records belonging to the CSA target hostname. The section
1237 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1238 If one of the addresses matches the client's IP address, then the client is
1239 authorized by CSA. If there are target IP addresses but none of them match
1240 then the client is using an unauthorized IP address. If there are no target IP
1241 addresses then the client cannot be using an authorized IP address. (This is
1242 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1245 dnsa the DNS answer block
1246 dnss a DNS scan block for us to use
1247 reset option specifying what portion to scan, as described above
1248 target the target hostname to use for matching RR names
1250 Returns: CSA_OK successfully authorized
1251 CSA_FAIL_MISMATCH addresses found but none matched
1252 CSA_FAIL_NOADDR no target addresses found
1256 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1262 BOOL target_found = FALSE;
1264 for (rr = dns_next_rr(dnsa, dnss, reset);
1266 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1268 /* Check this is an address RR for the target hostname. */
1272 && rr->type != T_AAAA
1276 if (strcmpic(target, rr->name) != 0) continue;
1278 target_found = TRUE;
1280 /* Turn the target address RR into a list of textual IP addresses and scan
1281 the list. There may be more than one if it is an A6 RR. */
1283 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1285 /* If the client IP address matches the target IP address, it's good! */
1287 DEBUG(D_acl) debug_printf_indent("CSA target address is %s\n", da->address);
1289 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1293 /* If we found some target addresses but none of them matched, the client is
1294 using an unauthorized IP address, otherwise the target has no authorized IP
1297 if (target_found) return CSA_FAIL_MISMATCH;
1298 else return CSA_FAIL_NOADDR;
1303 /*************************************************
1304 * Verify Client SMTP Authorization *
1305 *************************************************/
1307 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1308 to find the CSA SRV record corresponding to the domain argument, or
1309 $sender_helo_name if no argument is provided. It then checks that the
1310 client is authorized, and that its IP address corresponds to the SRV
1311 target's address by calling acl_verify_csa_address() above. The address
1312 should have been returned in the DNS response's ADDITIONAL section, but if
1313 not we perform another DNS lookup to get it.
1316 domain pointer to optional parameter following verify = csa
1318 Returns: CSA_UNKNOWN no valid CSA record found
1319 CSA_OK successfully authorized
1320 CSA_FAIL_* client is definitely not authorized
1321 CSA_DEFER_* there was a DNS problem
1325 acl_verify_csa(const uschar *domain)
1328 const uschar *found;
1329 int priority, weight, port;
1336 /* Work out the domain we are using for the CSA lookup. The default is the
1337 client's HELO domain. If the client has not said HELO, use its IP address
1338 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1340 while (isspace(*domain) && *domain != '\0') ++domain;
1341 if (*domain == '\0') domain = sender_helo_name;
1342 if (domain == NULL) domain = sender_host_address;
1343 if (sender_host_address == NULL) return CSA_UNKNOWN;
1345 /* If we have an address literal, strip off the framing ready for turning it
1346 into a domain. The framing consists of matched square brackets possibly
1347 containing a keyword and a colon before the actual IP address. */
1349 if (domain[0] == '[')
1351 const uschar *start = Ustrchr(domain, ':');
1352 if (start == NULL) start = domain;
1353 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1356 /* Turn domains that look like bare IP addresses into domains in the reverse
1357 DNS. This code also deals with address literals and $sender_host_address. It's
1358 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1359 address literals, but it's probably the most friendly thing to do. This is an
1360 extension to CSA, so we allow it to be turned off for proper conformance. */
1362 if (string_is_ip_address(domain, NULL) != 0)
1364 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1365 dns_build_reverse(domain, target);
1369 /* Find out if we've already done the CSA check for this domain. If we have,
1370 return the same result again. Otherwise build a new cached result structure
1371 for this domain. The name is filled in now, and the value is filled in when
1372 we return from this function. */
1374 t = tree_search(csa_cache, domain);
1375 if (t != NULL) return t->data.val;
1377 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1378 Ustrcpy(t->name, domain);
1379 (void)tree_insertnode(&csa_cache, t);
1381 /* Now we are ready to do the actual DNS lookup(s). */
1384 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1386 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1389 return t->data.val = CSA_DEFER_SRV;
1391 /* If we found nothing, the client's authorization is unknown. */
1395 return t->data.val = CSA_UNKNOWN;
1397 /* We got something! Go on to look at the reply in more detail. */
1403 /* Scan the reply for well-formed CSA SRV records. */
1405 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1407 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT)) if (rr->type == T_SRV)
1409 const uschar * p = rr->data;
1411 /* Extract the numerical SRV fields (p is incremented) */
1413 GETSHORT(priority, p);
1414 GETSHORT(weight, p);
1418 debug_printf_indent("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1420 /* Check the CSA version number */
1422 if (priority != 1) continue;
1424 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1425 found by dns_special_lookup() is a parent of the one we asked for), we check
1426 the subdomain assertions in the port field. At the moment there's only one
1427 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1428 SRV records of their own. */
1430 if (Ustrcmp(found, domain) != 0)
1431 return t->data.val = port & 1 ? CSA_FAIL_EXPLICIT : CSA_UNKNOWN;
1433 /* This CSA SRV record refers directly to our domain, so we check the value
1434 in the weight field to work out the domain's authorization. 0 and 1 are
1435 unauthorized; 3 means the client is authorized but we can't check the IP
1436 address in order to authenticate it, so we treat it as unknown; values
1437 greater than 3 are undefined. */
1439 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1441 if (weight > 2) continue;
1443 /* Weight == 2, which means the domain is authorized. We must check that the
1444 client's IP address is listed as one of the SRV target addresses. Save the
1445 target hostname then break to scan the additional data for its addresses. */
1447 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1448 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1450 DEBUG(D_acl) debug_printf_indent("CSA target is %s\n", target);
1455 /* If we didn't break the loop then no appropriate records were found. */
1457 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1459 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1460 A target of "." indicates there are no valid addresses, so the client cannot
1461 be authorized. (This is an odd configuration because weight=2 target=. is
1462 equivalent to weight=1, but we check for it in order to keep load off the
1463 root name servers.) Note that dn_expand() turns "." into "". */
1465 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1467 /* Scan the additional section of the CSA SRV reply for addresses belonging
1468 to the target. If the name server didn't return any additional data (e.g.
1469 because it does not fully support SRV records), we need to do another lookup
1470 to obtain the target addresses; otherwise we have a definitive result. */
1472 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1473 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1475 /* The DNS lookup type corresponds to the IP version used by the client. */
1478 if (Ustrchr(sender_host_address, ':') != NULL)
1481 #endif /* HAVE_IPV6 */
1485 lookup_dnssec_authenticated = NULL;
1486 switch (dns_lookup(&dnsa, target, type, NULL))
1488 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1491 return t->data.val = CSA_DEFER_ADDR;
1493 /* If the query succeeded, scan the addresses and return the result. */
1496 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1497 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1498 /* else fall through */
1500 /* If the target has no IP addresses, the client cannot have an authorized
1501 IP address. However, if the target site uses A6 records (not AAAA records)
1502 we have to do yet another lookup in order to check them. */
1506 return t->data.val = CSA_FAIL_NOADDR;
1512 /*************************************************
1513 * Handle verification (address & other) *
1514 *************************************************/
1516 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1517 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT,
1518 VERIFY_HDR_NAMES_ASCII
1523 unsigned where_allowed; /* bitmap */
1524 BOOL no_options; /* Never has /option(s) following */
1525 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1527 static verify_type_t verify_type_list[] = {
1528 /* name value where no-opt opt-sep */
1529 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, FALSE, 0 },
1530 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1531 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1532 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1533 { US"header_syntax", VERIFY_HDR_SYNTAX, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1534 { US"not_blind", VERIFY_NOT_BLIND, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1535 { US"header_sender", VERIFY_HDR_SNDR, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), FALSE, 0 },
1536 { US"sender", VERIFY_SNDR, (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)
1537 |(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP),
1539 { US"recipient", VERIFY_RCPT, (1<<ACL_WHERE_RCPT), FALSE, 0 },
1540 { US"header_names_ascii", VERIFY_HDR_NAMES_ASCII, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 }
1544 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1545 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1546 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1547 CALLOUT_HOLD, CALLOUT_TIME /* TIME must be last */
1553 BOOL has_option; /* Has =option(s) following */
1554 BOOL timeval; /* Has a time value */
1556 static callout_opt_t callout_opt_list[] = {
1557 /* name value flag has-opt has-time */
1558 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1559 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1560 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1561 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1562 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1563 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1564 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1565 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1566 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1567 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1568 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1569 { US"hold", CALLOUT_HOLD, vopt_callout_hold, FALSE, FALSE },
1570 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1575 /* This function implements the "verify" condition. It is called when
1576 encountered in any ACL, because some tests are almost always permitted. Some
1577 just don't make sense, and always fail (for example, an attempt to test a host
1578 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1581 where where called from
1582 addr the recipient address that the ACL is handling, or NULL
1583 arg the argument of "verify"
1584 user_msgptr pointer for user message
1585 log_msgptr pointer for log message
1586 basic_errno where to put verify errno
1588 Returns: OK verification condition succeeded
1589 FAIL verification failed
1590 DEFER there was a problem verifying
1595 acl_verify(int where, address_item *addr, const uschar *arg,
1596 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1600 int callout_overall = -1;
1601 int callout_connect = -1;
1602 int verify_options = 0;
1604 BOOL verify_header_sender = FALSE;
1605 BOOL defer_ok = FALSE;
1606 BOOL callout_defer_ok = FALSE;
1607 BOOL no_details = FALSE;
1608 BOOL success_on_redirect = FALSE;
1609 address_item *sender_vaddr = NULL;
1610 uschar *verify_sender_address = NULL;
1611 uschar *pm_mailfrom = NULL;
1612 uschar *se_mailfrom = NULL;
1614 /* Some of the verify items have slash-separated options; some do not. Diagnose
1615 an error if options are given for items that don't expect them.
1618 uschar *slash = Ustrchr(arg, '/');
1619 const uschar *list = arg;
1620 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1623 if (ss == NULL) goto BAD_VERIFY;
1625 /* Handle name/address consistency verification in a separate function. */
1627 for (vp= verify_type_list;
1628 CS vp < CS verify_type_list + sizeof(verify_type_list);
1631 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1632 : strcmpic (ss, vp->name) == 0)
1634 if (CS vp >= CS verify_type_list + sizeof(verify_type_list))
1637 if (vp->no_options && slash != NULL)
1639 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1640 "(this verify item has no options)", arg);
1643 if (!(vp->where_allowed & (1<<where)))
1645 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", vp->name, acl_wherenames[where]);
1650 case VERIFY_REV_HOST_LKUP:
1651 if (sender_host_address == NULL) return OK;
1652 if ((rc = acl_verify_reverse(user_msgptr, log_msgptr)) == DEFER)
1653 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
1654 if (strcmpic(ss, US"defer_ok") == 0)
1659 /* TLS certificate verification is done at STARTTLS time; here we just
1660 test whether it was successful or not. (This is for optional verification; for
1661 mandatory verification, the connection doesn't last this long.) */
1663 if (tls_in.certificate_verified) return OK;
1664 *user_msgptr = US"no verified certificate";
1668 /* We can test the result of optional HELO verification that might have
1669 occurred earlier. If not, we can attempt the verification now. */
1671 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1672 return helo_verified? OK : FAIL;
1675 /* Do Client SMTP Authorization checks in a separate function, and turn the
1676 result code into user-friendly strings. */
1678 rc = acl_verify_csa(list);
1679 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1680 csa_reason_string[rc]);
1681 csa_status = csa_status_string[rc];
1682 DEBUG(D_acl) debug_printf_indent("CSA result %s\n", csa_status);
1683 return csa_return_code[rc];
1685 case VERIFY_HDR_SYNTAX:
1686 /* Check that all relevant header lines have the correct syntax. If there is
1687 a syntax error, we return details of the error to the sender if configured to
1688 send out full details. (But a "message" setting on the ACL can override, as
1691 rc = verify_check_headers(log_msgptr);
1692 if (rc != OK && *log_msgptr)
1693 if (smtp_return_error_details)
1694 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1696 acl_verify_message = *log_msgptr;
1699 case VERIFY_HDR_NAMES_ASCII:
1700 /* Check that all header names are true 7 bit strings
1701 See RFC 5322, 2.2. and RFC 6532, 3. */
1703 rc = verify_check_header_names_ascii(log_msgptr);
1704 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1705 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1708 case VERIFY_NOT_BLIND:
1709 /* Check that no recipient of this message is "blind", that is, every envelope
1710 recipient must be mentioned in either To: or Cc:. */
1712 rc = verify_check_notblind();
1715 *log_msgptr = string_sprintf("bcc recipient detected");
1716 if (smtp_return_error_details)
1717 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1721 /* The remaining verification tests check recipient and sender addresses,
1722 either from the envelope or from the header. There are a number of
1723 slash-separated options that are common to all of them. */
1725 case VERIFY_HDR_SNDR:
1726 verify_header_sender = TRUE;
1730 /* In the case of a sender, this can optionally be followed by an address to use
1731 in place of the actual sender (rare special-case requirement). */
1735 verify_sender_address = sender_address;
1738 while (isspace(*s)) s++;
1739 if (*s++ != '=') goto BAD_VERIFY;
1740 while (isspace(*s)) s++;
1741 verify_sender_address = string_copy(s);
1752 /* Remaining items are optional; they apply to sender and recipient
1753 verification, including "header sender" verification. */
1755 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1758 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1759 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1760 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1762 /* These two old options are left for backwards compatibility */
1764 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1766 callout_defer_ok = TRUE;
1767 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1770 else if (strcmpic(ss, US"check_postmaster") == 0)
1773 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1776 /* The callout option has a number of sub-options, comma separated */
1778 else if (strncmpic(ss, US"callout", 7) == 0)
1780 callout = CALLOUT_TIMEOUT_DEFAULT;
1784 while (isspace(*ss)) ss++;
1787 const uschar * sublist = ss;
1791 while (isspace(*sublist)) sublist++;
1793 while ((opt = string_nextinlist(&sublist, &optsep, buffer, sizeof(buffer))))
1796 double period = 1.0F;
1798 for (op= callout_opt_list; op->name; op++)
1799 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1802 verify_options |= op->flag;
1805 opt += Ustrlen(op->name);
1806 while (isspace(*opt)) opt++;
1809 *log_msgptr = string_sprintf("'=' expected after "
1810 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1813 while (isspace(*opt)) opt++;
1815 if (op->timeval && (period = readconf_readtime(opt, 0, FALSE)) < 0)
1817 *log_msgptr = string_sprintf("bad time value in ACL condition "
1818 "\"verify %s\"", arg);
1824 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1825 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1826 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1827 case CALLOUT_MAILFROM:
1828 if (!verify_header_sender)
1830 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1831 "callout option only for verify=header_sender (detected in ACL "
1832 "condition \"%s\")", arg);
1835 se_mailfrom = string_copy(opt);
1837 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1838 case CALLOUT_MAXWAIT: callout_overall = period; break;
1839 case CALLOUT_CONNECT: callout_connect = period; break;
1840 case CALLOUT_TIME: callout = period; break;
1846 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1847 "ACL condition \"%s\"", arg);
1853 /* Option not recognized */
1857 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1858 "condition \"verify %s\"", ss, arg);
1863 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1864 (vopt_callout_recipsender|vopt_callout_recippmaster))
1866 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1867 "for a recipient callout";
1871 /* Handle sender-in-header verification. Default the user message to the log
1872 message if giving out verification details. */
1874 if (verify_header_sender)
1878 if ((rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1879 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1882 *basic_errno = verrno;
1883 if (smtp_return_error_details)
1885 if (!*user_msgptr && *log_msgptr)
1886 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1887 if (rc == DEFER) acl_temp_details = TRUE;
1892 /* Handle a sender address. The default is to verify *the* sender address, but
1893 optionally a different address can be given, for special requirements. If the
1894 address is empty, we are dealing with a bounce message that has no sender, so
1895 we cannot do any checking. If the real sender address gets rewritten during
1896 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1897 during message reception.
1899 A list of verified "sender" addresses is kept to try to avoid doing to much
1900 work repetitively when there are multiple recipients in a message and they all
1901 require sender verification. However, when callouts are involved, it gets too
1902 complicated because different recipients may require different callout options.
1903 Therefore, we always do a full sender verify when any kind of callout is
1904 specified. Caching elsewhere, for instance in the DNS resolver and in the
1905 callout handling, should ensure that this is not terribly inefficient. */
1907 else if (verify_sender_address)
1909 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)))
1911 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1912 "sender verify callout";
1916 sender_vaddr = verify_checked_sender(verify_sender_address);
1917 if (sender_vaddr != NULL && /* Previously checked */
1918 callout <= 0) /* No callout needed this time */
1920 /* If the "routed" flag is set, it means that routing worked before, so
1921 this check can give OK (the saved return code value, if set, belongs to a
1922 callout that was done previously). If the "routed" flag is not set, routing
1923 must have failed, so we use the saved return code. */
1925 if (testflag(sender_vaddr, af_verify_routed))
1929 rc = sender_vaddr->special_action;
1930 *basic_errno = sender_vaddr->basic_errno;
1932 HDEBUG(D_acl) debug_printf_indent("using cached sender verify result\n");
1935 /* Do a new verification, and cache the result. The cache is used to avoid
1936 verifying the sender multiple times for multiple RCPTs when callouts are not
1937 specified (see comments above).
1939 The cache is also used on failure to give details in response to the first
1940 RCPT that gets bounced for this reason. However, this can be suppressed by
1941 the no_details option, which sets the flag that says "this detail has already
1942 been sent". The cache normally contains just one address, but there may be
1943 more in esoteric circumstances. */
1948 uschar *save_address_data = deliver_address_data;
1950 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1952 if ((sender_vaddr->prop.utf8_msg = message_smtputf8))
1954 sender_vaddr->prop.utf8_downcvt = message_utf8_downconvert == 1;
1955 sender_vaddr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
1958 if (no_details) setflag(sender_vaddr, af_sverify_told);
1959 if (verify_sender_address[0] != 0)
1961 /* If this is the real sender address, save the unrewritten version
1962 for use later in receive. Otherwise, set a flag so that rewriting the
1963 sender in verify_address() does not update sender_address. */
1965 if (verify_sender_address == sender_address)
1966 sender_address_unrewritten = sender_address;
1968 verify_options |= vopt_fake_sender;
1970 if (success_on_redirect)
1971 verify_options |= vopt_success_on_redirect;
1973 /* The recipient, qualify, and expn options are never set in
1976 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1977 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1979 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
1982 *basic_errno = sender_vaddr->basic_errno;
1986 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1987 debug_printf_indent("sender %s verified ok as %s\n",
1988 verify_sender_address, sender_vaddr->address);
1990 debug_printf_indent("sender %s verified ok\n",
1991 verify_sender_address);
1995 rc = OK; /* Null sender */
1997 /* Cache the result code */
1999 if (routed) setflag(sender_vaddr, af_verify_routed);
2000 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
2001 sender_vaddr->special_action = rc;
2002 sender_vaddr->next = sender_verified_list;
2003 sender_verified_list = sender_vaddr;
2005 /* Restore the recipient address data, which might have been clobbered by
2006 the sender verification. */
2008 deliver_address_data = save_address_data;
2011 /* Put the sender address_data value into $sender_address_data */
2013 sender_address_data = sender_vaddr->prop.address_data;
2016 /* A recipient address just gets a straightforward verify; again we must handle
2017 the DEFER overrides. */
2023 if (success_on_redirect)
2024 verify_options |= vopt_success_on_redirect;
2026 /* We must use a copy of the address for verification, because it might
2030 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
2031 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
2032 HDEBUG(D_acl) debug_printf_indent("----------- end verify ------------\n");
2034 *basic_errno = addr2.basic_errno;
2035 *log_msgptr = addr2.message;
2036 *user_msgptr = (addr2.user_message != NULL)?
2037 addr2.user_message : addr2.message;
2039 /* Allow details for temporary error if the address is so flagged. */
2040 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
2042 /* Make $address_data visible */
2043 deliver_address_data = addr2.prop.address_data;
2046 /* We have a result from the relevant test. Handle defer overrides first. */
2048 if (rc == DEFER && (defer_ok ||
2049 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
2051 HDEBUG(D_acl) debug_printf_indent("verify defer overridden by %s\n",
2052 defer_ok? "defer_ok" : "callout_defer_ok");
2056 /* If we've failed a sender, set up a recipient message, and point
2057 sender_verified_failed to the address item that actually failed. */
2059 if (rc != OK && verify_sender_address != NULL)
2062 *log_msgptr = *user_msgptr = US"Sender verify failed";
2063 else if (*basic_errno != ERRNO_CALLOUTDEFER)
2064 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
2067 *log_msgptr = US"Could not complete sender verify callout";
2068 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2072 sender_verified_failed = sender_vaddr;
2075 /* Verifying an address messes up the values of $domain and $local_part,
2076 so reset them before returning if this is a RCPT ACL. */
2080 deliver_domain = addr->domain;
2081 deliver_localpart = addr->local_part;
2085 /* Syntax errors in the verify argument come here. */
2088 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2089 "\"helo\", \"header_syntax\", \"header_sender\", \"header_names_ascii\" "
2090 "or \"reverse_host_lookup\" at start of ACL condition "
2091 "\"verify %s\"", arg);
2098 /*************************************************
2099 * Check argument for control= modifier *
2100 *************************************************/
2102 /* Called from acl_check_condition() below
2105 arg the argument string for control=
2106 pptr set to point to the terminating character
2107 where which ACL we are in
2108 log_msgptr for error messages
2110 Returns: CONTROL_xxx value
2114 decode_control(const uschar *arg, const uschar **pptr, int where, uschar **log_msgptr)
2119 if ( (idx = find_control(arg, controls_list, nelem(controls_list))) < 0
2120 || ( arg[len = Ustrlen((d = controls_list+idx)->name)] != 0
2121 && (!d->has_option || arg[len] != '/')
2124 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2125 return CONTROL_ERROR;
2135 /*************************************************
2136 * Return a ratelimit error *
2137 *************************************************/
2139 /* Called from acl_ratelimit() below
2142 log_msgptr for error messages
2143 format format string
2144 ... supplementary arguments
2145 ss ratelimit option name
2146 where ACL_WHERE_xxxx indicating which ACL this is
2152 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2155 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2156 va_start(ap, format);
2157 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2158 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2159 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2161 *log_msgptr = string_sprintf(
2162 "error in arguments to \"ratelimit\" condition: %s", buffer);
2169 /*************************************************
2170 * Handle rate limiting *
2171 *************************************************/
2173 /* Called by acl_check_condition() below to calculate the result
2174 of the ACL ratelimit condition.
2176 Note that the return value might be slightly unexpected: if the
2177 sender's rate is above the limit then the result is OK. This is
2178 similar to the dnslists condition, and is so that you can write
2179 ACL clauses like: defer ratelimit = 15 / 1h
2182 arg the option string for ratelimit=
2183 where ACL_WHERE_xxxx indicating which ACL this is
2184 log_msgptr for error messages
2186 Returns: OK - Sender's rate is above limit
2187 FAIL - Sender's rate is below limit
2188 DEFER - Problem opening ratelimit database
2189 ERROR - Syntax error in options.
2193 acl_ratelimit(const uschar *arg, int where, uschar **log_msgptr)
2195 double limit, period, count;
2198 uschar *unique = NULL;
2200 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2201 BOOL noupdate = FALSE, badacl = FALSE;
2202 int mode = RATE_PER_WHAT;
2204 tree_node **anchor, *t;
2205 open_db dbblock, *dbm;
2207 dbdata_ratelimit *dbd;
2208 dbdata_ratelimit_unique *dbdb;
2211 /* Parse the first two options and record their values in expansion
2212 variables. These variables allow the configuration to have informative
2213 error messages based on rate limits obtained from a table lookup. */
2215 /* First is the maximum number of messages per period / maximum burst
2216 size, which must be greater than or equal to zero. Zero is useful for
2217 rate measurement as opposed to rate limiting. */
2219 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2220 if (sender_rate_limit == NULL)
2221 return ratelimit_error(log_msgptr, "sender rate limit not set");
2223 limit = Ustrtod(sender_rate_limit, &ss);
2224 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2225 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2226 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2228 if (limit < 0.0 || *ss != '\0')
2229 return ratelimit_error(log_msgptr,
2230 "\"%s\" is not a positive number", sender_rate_limit);
2232 /* Second is the rate measurement period / exponential smoothing time
2233 constant. This must be strictly greater than zero, because zero leads to
2234 run-time division errors. */
2236 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2237 if (sender_rate_period == NULL) period = -1.0;
2238 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2240 return ratelimit_error(log_msgptr,
2241 "\"%s\" is not a time value", sender_rate_period);
2243 /* By default we are counting one of something, but the per_rcpt,
2244 per_byte, and count options can change this. */
2248 /* Parse the other options. */
2250 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2253 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2254 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2255 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2256 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2257 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2258 else if (strcmpic(ss, US"per_conn") == 0)
2260 RATE_SET(mode, PER_CONN);
2261 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2264 else if (strcmpic(ss, US"per_mail") == 0)
2266 RATE_SET(mode, PER_MAIL);
2267 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2269 else if (strcmpic(ss, US"per_rcpt") == 0)
2271 /* If we are running in the RCPT ACL, then we'll count the recipients
2272 one by one, but if we are running when we have accumulated the whole
2273 list then we'll add them all in one batch. */
2274 if (where == ACL_WHERE_RCPT)
2275 RATE_SET(mode, PER_RCPT);
2276 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2277 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2278 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2279 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2281 else if (strcmpic(ss, US"per_byte") == 0)
2283 /* If we have not yet received the message data and there was no SIZE
2284 declaration on the MAIL command, then it's safe to just use a value of
2285 zero and let the recorded rate decay as if nothing happened. */
2286 RATE_SET(mode, PER_MAIL);
2287 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2288 else count = message_size < 0 ? 0.0 : (double)message_size;
2290 else if (strcmpic(ss, US"per_addr") == 0)
2292 RATE_SET(mode, PER_RCPT);
2293 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2294 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2296 else if (strncmpic(ss, US"count=", 6) == 0)
2299 count = Ustrtod(ss+6, &e);
2300 if (count < 0.0 || *e != '\0')
2301 return ratelimit_error(log_msgptr,
2302 "\"%s\" is not a positive number", ss);
2304 else if (strncmpic(ss, US"unique=", 7) == 0)
2305 unique = string_copy(ss + 7);
2306 else if (key == NULL)
2307 key = string_copy(ss);
2309 key = string_sprintf("%s/%s", key, ss);
2312 /* Sanity check. When the badacl flag is set the update mode must either
2313 be readonly (which is the default if it is omitted) or, for backwards
2314 compatibility, a combination of noupdate and strict or leaky. */
2316 if (mode == RATE_PER_CLASH)
2317 return ratelimit_error(log_msgptr, "conflicting per_* options");
2318 if (leaky + strict + readonly > 1)
2319 return ratelimit_error(log_msgptr, "conflicting update modes");
2320 if (badacl && (leaky || strict) && !noupdate)
2321 return ratelimit_error(log_msgptr,
2322 "\"%s\" must not have /leaky or /strict option in %s ACL",
2323 ratelimit_option_string[mode], acl_wherenames[where]);
2325 /* Set the default values of any unset options. In readonly mode we
2326 perform the rate computation without any increment so that its value
2327 decays to eventually allow over-limit senders through. */
2329 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2330 if (badacl) readonly = TRUE;
2331 if (readonly) count = 0.0;
2332 if (!strict && !readonly) leaky = TRUE;
2333 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2335 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2336 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2337 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2338 are added to the key because they alter the meaning of the stored data. */
2341 key = (sender_host_address == NULL)? US"" : sender_host_address;
2343 key = string_sprintf("%s/%s/%s%s",
2345 ratelimit_option_string[mode],
2346 unique == NULL ? "" : "unique/",
2350 debug_printf_indent("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2352 /* See if we have already computed the rate by looking in the relevant tree.
2353 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2354 pool so that they survive across resets. In readonly mode we only remember the
2355 result for the rest of this command in case a later command changes it. After
2356 this bit of logic the code is independent of the per_* mode. */
2358 old_pool = store_pool;
2361 anchor = &ratelimiters_cmd;
2364 anchor = &ratelimiters_conn;
2365 store_pool = POOL_PERM;
2369 case RATE_PER_ALLRCPTS:
2370 anchor = &ratelimiters_mail;
2375 anchor = &ratelimiters_cmd;
2378 anchor = NULL; /* silence an "unused" complaint */
2379 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2380 "internal ACL error: unknown ratelimit mode %d", mode);
2384 t = tree_search(*anchor, key);
2388 /* The following few lines duplicate some of the code below. */
2389 rc = (dbd->rate < limit)? FAIL : OK;
2390 store_pool = old_pool;
2391 sender_rate = string_sprintf("%.1f", dbd->rate);
2393 debug_printf_indent("ratelimit found pre-computed rate %s\n", sender_rate);
2397 /* We aren't using a pre-computed rate, so get a previously recorded rate
2398 from the database, which will be updated and written back if required. */
2400 if (!(dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE)))
2402 store_pool = old_pool;
2404 HDEBUG(D_acl) debug_printf_indent("ratelimit database not available\n");
2405 *log_msgptr = US"ratelimit database not available";
2408 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2411 gettimeofday(&tv, NULL);
2415 /* Locate the basic ratelimit block inside the DB data. */
2416 HDEBUG(D_acl) debug_printf_indent("ratelimit found key in database\n");
2419 /* Forget the old Bloom filter if it is too old, so that we count each
2420 repeating event once per period. We don't simply clear and re-use the old
2421 filter because we want its size to change if the limit changes. Note that
2422 we keep the dbd pointer for copying the rate into the new data block. */
2424 if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period)
2426 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding old Bloom filter\n");
2432 if(unique != NULL && dbdb_size < sizeof(*dbdb))
2434 HDEBUG(D_acl) debug_printf_indent("ratelimit discarding undersize Bloom filter\n");
2439 /* Allocate a new data block if the database lookup failed
2440 or the Bloom filter passed its age limit. */
2446 /* No Bloom filter. This basic ratelimit block is initialized below. */
2447 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new rate data block\n");
2448 dbdb_size = sizeof(*dbd);
2449 dbdb = store_get(dbdb_size);
2454 HDEBUG(D_acl) debug_printf_indent("ratelimit creating new Bloom filter\n");
2456 /* See the long comment below for an explanation of the magic number 2.
2457 The filter has a minimum size in case the rate limit is very small;
2458 this is determined by the definition of dbdata_ratelimit_unique. */
2460 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2461 if (extra < 0) extra = 0;
2462 dbdb_size = sizeof(*dbdb) + extra;
2463 dbdb = store_get(dbdb_size);
2464 dbdb->bloom_epoch = tv.tv_sec;
2465 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2466 memset(dbdb->bloom, 0, dbdb->bloom_size);
2468 /* Preserve any basic ratelimit data (which is our longer-term memory)
2469 by copying it from the discarded block. */
2479 /* If we are counting unique events, find out if this event is new or not.
2480 If the client repeats the event during the current period then it should be
2481 counted. We skip this code in readonly mode for efficiency, because any
2482 changes to the filter will be discarded and because count is already set to
2485 if (unique != NULL && !readonly)
2487 /* We identify unique events using a Bloom filter. (You can find my
2488 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2489 With the per_addr option, an "event" is a recipient address, though the
2490 user can use the unique option to define their own events. We only count
2491 an event if we have not seen it before.
2493 We size the filter according to the rate limit, which (in leaky mode)
2494 is the limit on the population of the filter. We allow 16 bits of space
2495 per entry (see the construction code above) and we set (up to) 8 of them
2496 when inserting an element (see the loop below). The probability of a false
2497 positive (an event we have not seen before but which we fail to count) is
2501 allzero = exp(-numhash * pop / size)
2502 = exp(-0.5 * pop / limit)
2503 fpr = pow(1 - allzero, numhash)
2505 For senders at the limit the fpr is 0.06% or 1 in 1700
2506 and for senders at half the limit it is 0.0006% or 1 in 170000
2508 In strict mode the Bloom filter can fill up beyond the normal limit, in
2509 which case the false positive rate will rise. This means that the
2510 measured rate for very fast senders can bogusly drop off after a while.
2512 At twice the limit, the fpr is 2.5% or 1 in 40
2513 At four times the limit, it is 31% or 1 in 3.2
2515 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2516 decay below the limit, and if this is more than one then the Bloom filter
2517 will be discarded before the decay gets that far. The false positive rate
2518 at this threshold is 9.3% or 1 in 10.7. */
2521 unsigned n, hash, hinc;
2525 /* Instead of using eight independent hash values, we combine two values
2526 using the formula h1 + n * h2. This does not harm the Bloom filter's
2527 performance, and means the amount of hash we need is independent of the
2528 number of bits we set in the filter. */
2530 md5_start(&md5info);
2531 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2532 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2533 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2535 /* Scan the bits corresponding to this event. A zero bit means we have
2536 not seen it before. Ensure all bits are set to record this event. */
2538 HDEBUG(D_acl) debug_printf_indent("ratelimit checking uniqueness of %s\n", unique);
2541 for (n = 0; n < 8; n++, hash += hinc)
2543 int bit = 1 << (hash % 8);
2544 int byte = (hash / 8) % dbdb->bloom_size;
2545 if ((dbdb->bloom[byte] & bit) == 0)
2547 dbdb->bloom[byte] |= bit;
2552 /* If this event has occurred before, do not count it. */
2556 HDEBUG(D_acl) debug_printf_indent("ratelimit event found in Bloom filter\n");
2560 HDEBUG(D_acl) debug_printf_indent("ratelimit event added to Bloom filter\n");
2563 /* If there was no previous ratelimit data block for this key, initialize
2564 the new one, otherwise update the block from the database. The initial rate
2565 is what would be computed by the code below for an infinite interval. */
2569 HDEBUG(D_acl) debug_printf_indent("ratelimit initializing new key's rate data\n");
2571 dbd->time_stamp = tv.tv_sec;
2572 dbd->time_usec = tv.tv_usec;
2577 /* The smoothed rate is computed using an exponentially weighted moving
2578 average adjusted for variable sampling intervals. The standard EWMA for
2579 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2580 where f() is the measured value and f'() is the smoothed value.
2582 Old data decays out of the smoothed value exponentially, such that data n
2583 samples old is multiplied by a^n. The exponential decay time constant p
2584 is defined such that data p samples old is multiplied by 1/e, which means
2585 that a = exp(-1/p). We can maintain the same time constant for a variable
2586 sampling interval i by using a = exp(-i/p).
2588 The rate we are measuring is messages per period, suitable for directly
2589 comparing with the limit. The average rate between now and the previous
2590 message is period / interval, which we feed into the EWMA as the sample.
2592 It turns out that the number of messages required for the smoothed rate
2593 to reach the limit when they are sent in a burst is equal to the limit.
2594 This can be seen by analysing the value of the smoothed rate after N
2595 messages sent at even intervals. Let k = (1 - a) * p/i
2597 rate_1 = (1 - a) * p/i + a * rate_0
2599 rate_2 = k + a * rate_1
2600 = k + a * k + a^2 * rate_0
2601 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2602 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2603 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2604 = rate_0 * a^N + p/i * (1 - a^N)
2606 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2608 rate_N = p/i + (rate_0 - p/i) * a^N
2609 a^N = (rate_N - p/i) / (rate_0 - p/i)
2610 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2611 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2613 Numerical analysis of the above equation, setting the computed rate to
2614 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2615 rates, p/i, the number of messages N = limit. So limit serves as both the
2616 maximum rate measured in messages per period, and the maximum number of
2617 messages that can be sent in a fast burst. */
2619 double this_time = (double)tv.tv_sec
2620 + (double)tv.tv_usec / 1000000.0;
2621 double prev_time = (double)dbd->time_stamp
2622 + (double)dbd->time_usec / 1000000.0;
2624 /* We must avoid division by zero, and deal gracefully with the clock going
2625 backwards. If we blunder ahead when time is in reverse then the computed
2626 rate will be bogus. To be safe we clamp interval to a very small number. */
2628 double interval = this_time - prev_time <= 0.0 ? 1e-9
2629 : this_time - prev_time;
2631 double i_over_p = interval / period;
2632 double a = exp(-i_over_p);
2634 /* Combine the instantaneous rate (period / interval) with the previous rate
2635 using the smoothing factor a. In order to measure sized events, multiply the
2636 instantaneous rate by the count of bytes or recipients etc. */
2638 dbd->time_stamp = tv.tv_sec;
2639 dbd->time_usec = tv.tv_usec;
2640 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2642 /* When events are very widely spaced the computed rate tends towards zero.
2643 Although this is accurate it turns out not to be useful for our purposes,
2644 especially when the first event after a long silence is the start of a spam
2645 run. A more useful model is that the rate for an isolated event should be the
2646 size of the event per the period size, ignoring the lack of events outside
2647 the current period and regardless of where the event falls in the period. So,
2648 if the interval was so long that the calculated rate is unhelpfully small, we
2649 re-initialize the rate. In the absence of higher-rate bursts, the condition
2650 below is true if the interval is greater than the period. */
2652 if (dbd->rate < count) dbd->rate = count;
2655 /* Clients sending at the limit are considered to be over the limit.
2656 This matters for edge cases such as a limit of zero, when the client
2657 should be completely blocked. */
2659 rc = (dbd->rate < limit)? FAIL : OK;
2661 /* Update the state if the rate is low or if we are being strict. If we
2662 are in leaky mode and the sender's rate is too high, we do not update
2663 the recorded rate in order to avoid an over-aggressive sender's retry
2664 rate preventing them from getting any email through. If readonly is set,
2665 neither leaky nor strict are set, so we do not do any updates. */
2667 if ((rc == FAIL && leaky) || strict)
2669 dbfn_write(dbm, key, dbdb, dbdb_size);
2670 HDEBUG(D_acl) debug_printf_indent("ratelimit db updated\n");
2674 HDEBUG(D_acl) debug_printf_indent("ratelimit db not updated: %s\n",
2675 readonly? "readonly mode" : "over the limit, but leaky");
2680 /* Store the result in the tree for future reference. */
2682 t = store_get(sizeof(tree_node) + Ustrlen(key));
2684 Ustrcpy(t->name, key);
2685 (void)tree_insertnode(anchor, t);
2687 /* We create the formatted version of the sender's rate very late in
2688 order to ensure that it is done using the correct storage pool. */
2690 store_pool = old_pool;
2691 sender_rate = string_sprintf("%.1f", dbd->rate);
2694 debug_printf_indent("ratelimit computed rate %s\n", sender_rate);
2701 /*************************************************
2702 * The udpsend ACL modifier *
2703 *************************************************/
2705 /* Called by acl_check_condition() below.
2708 arg the option string for udpsend=
2709 log_msgptr for error messages
2711 Returns: OK - Completed.
2712 DEFER - Problem with DNS lookup.
2713 ERROR - Syntax error in options.
2717 acl_udpsend(const uschar *arg, uschar **log_msgptr)
2729 hostname = string_nextinlist(&arg, &sep, NULL, 0);
2730 portstr = string_nextinlist(&arg, &sep, NULL, 0);
2734 *log_msgptr = US"missing destination host in \"udpsend\" modifier";
2739 *log_msgptr = US"missing destination port in \"udpsend\" modifier";
2744 *log_msgptr = US"missing datagram payload in \"udpsend\" modifier";
2747 portnum = Ustrtol(portstr, &portend, 10);
2748 if (*portend != '\0')
2750 *log_msgptr = US"bad destination port in \"udpsend\" modifier";
2754 /* Make a single-item host list. */
2755 h = store_get(sizeof(host_item));
2756 memset(h, 0, sizeof(host_item));
2761 if (string_is_ip_address(hostname, NULL))
2762 h->address = hostname, r = HOST_FOUND;
2764 r = host_find_byname(h, NULL, 0, NULL, FALSE);
2765 if (r == HOST_FIND_FAILED || r == HOST_FIND_AGAIN)
2767 *log_msgptr = US"DNS lookup failed in \"udpsend\" modifier";
2772 debug_printf_indent("udpsend [%s]:%d %s\n", h->address, portnum, arg);
2774 /*XXX this could better use sendto */
2775 r = s = ip_connectedsocket(SOCK_DGRAM, h->address, portnum, portnum,
2776 1, NULL, &errstr, NULL);
2777 if (r < 0) goto defer;
2779 r = send(s, arg, len, 0);
2782 errstr = US strerror(errno);
2790 string_sprintf("\"udpsend\" truncated from %d to %d octets", len, r);
2795 debug_printf_indent("udpsend %d bytes\n", r);
2800 *log_msgptr = string_sprintf("\"udpsend\" failed: %s", errstr);
2806 /*************************************************
2807 * Handle conditions/modifiers on an ACL item *
2808 *************************************************/
2810 /* Called from acl_check() below.
2814 cb ACL condition block - if NULL, result is OK
2815 where where called from
2816 addr the address being checked for RCPT, or NULL
2817 level the nesting level
2818 epp pointer to pass back TRUE if "endpass" encountered
2819 (applies only to "accept" and "discard")
2820 user_msgptr user message pointer
2821 log_msgptr log message pointer
2822 basic_errno pointer to where to put verify error
2824 Returns: OK - all conditions are met
2825 DISCARD - an "acl" condition returned DISCARD - only allowed
2826 for "accept" or "discard" verbs
2827 FAIL - at least one condition fails
2828 FAIL_DROP - an "acl" condition returned FAIL_DROP
2829 DEFER - can't tell at the moment (typically, lookup defer,
2830 but can be temporary callout problem)
2831 ERROR - ERROR from nested ACL or expansion failure or other
2836 acl_check_condition(int verb, acl_condition_block *cb, int where,
2837 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2838 uschar **log_msgptr, int *basic_errno)
2840 uschar *user_message = NULL;
2841 uschar *log_message = NULL;
2843 #ifdef WITH_CONTENT_SCAN
2847 for (; cb != NULL; cb = cb->next)
2852 /* The message and log_message items set up messages to be used in
2853 case of rejection. They are expanded later. */
2855 if (cb->type == ACLC_MESSAGE)
2857 HDEBUG(D_acl) debug_printf_indent(" message: %s\n", cb->arg);
2858 user_message = cb->arg;
2862 if (cb->type == ACLC_LOG_MESSAGE)
2864 HDEBUG(D_acl) debug_printf_indent("l_message: %s\n", cb->arg);
2865 log_message = cb->arg;
2869 /* The endpass "condition" just sets a flag to show it occurred. This is
2870 checked at compile time to be on an "accept" or "discard" item. */
2872 if (cb->type == ACLC_ENDPASS)
2878 /* For other conditions and modifiers, the argument is expanded now for some
2879 of them, but not for all, because expansion happens down in some lower level
2880 checking functions in some cases. */
2882 if (!conditions[cb->type].expand_at_top)
2884 else if (!(arg = expand_string(cb->arg)))
2886 if (expand_string_forcedfail) continue;
2887 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2888 cb->arg, expand_string_message);
2889 return search_find_defer ? DEFER : ERROR;
2892 /* Show condition, and expanded condition if it's different */
2897 debug_printf_indent("check %s%s %n",
2898 (!conditions[cb->type].is_modifier && cb->u.negated)? "!":"",
2899 conditions[cb->type].name, &lhswidth);
2901 if (cb->type == ACLC_SET)
2903 debug_printf("acl_%s ", cb->u.varname);
2904 lhswidth += 5 + Ustrlen(cb->u.varname);
2907 debug_printf("= %s\n", cb->arg);
2910 debug_printf("%.*s= %s\n", lhswidth,
2914 /* Check that this condition makes sense at this time */
2916 if ((conditions[cb->type].forbids & (1 << where)) != 0)
2918 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2919 conditions[cb->type].is_modifier ? "use" : "test",
2920 conditions[cb->type].name, acl_wherenames[where]);
2924 /* Run the appropriate test for each condition, or take the appropriate
2925 action for the remaining modifiers. */
2929 case ACLC_ADD_HEADER:
2933 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2937 rc = acl_check_wargs(where, addr, arg, user_msgptr, log_msgptr);
2938 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2940 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2941 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2947 case ACLC_AUTHENTICATED:
2948 rc = (sender_host_authenticated == NULL)? FAIL :
2949 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2953 #ifdef EXPERIMENTAL_BRIGHTMAIL
2954 case ACLC_BMI_OPTIN:
2956 int old_pool = store_pool;
2957 store_pool = POOL_PERM;
2958 bmi_current_optin = string_copy(arg);
2959 store_pool = old_pool;
2964 case ACLC_CONDITION:
2965 /* The true/false parsing here should be kept in sync with that used in
2966 expand.c when dealing with ECOND_BOOL so that we don't have too many
2967 different definitions of what can be a boolean. */
2969 ? Ustrspn(arg+1, "0123456789") == Ustrlen(arg+1) /* Negative number */
2970 : Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2971 rc = (Uatoi(arg) == 0)? FAIL : OK;
2973 rc = (strcmpic(arg, US"no") == 0 ||
2974 strcmpic(arg, US"false") == 0)? FAIL :
2975 (strcmpic(arg, US"yes") == 0 ||
2976 strcmpic(arg, US"true") == 0)? OK : DEFER;
2978 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2981 case ACLC_CONTINUE: /* Always succeeds */
2986 const uschar *p = NULL;
2987 control_type = decode_control(arg, &p, where, log_msgptr);
2989 /* Check if this control makes sense at this time */
2991 if (controls_list[control_type].forbids & (1 << where))
2993 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2994 controls_list[control_type].name, acl_wherenames[where]);
2998 switch(control_type)
3000 case CONTROL_AUTH_UNADVERTISED:
3001 allow_auth_unadvertised = TRUE;
3004 #ifdef EXPERIMENTAL_BRIGHTMAIL
3005 case CONTROL_BMI_RUN:
3010 #ifndef DISABLE_DKIM
3011 case CONTROL_DKIM_VERIFY:
3012 dkim_disable_verify = TRUE;
3013 #ifdef EXPERIMENTAL_DMARC
3014 /* Since DKIM was blocked, skip DMARC too */
3015 dmarc_disable_verify = TRUE;
3016 dmarc_enable_forensic = FALSE;
3021 #ifdef EXPERIMENTAL_DMARC
3022 case CONTROL_DMARC_VERIFY:
3023 dmarc_disable_verify = TRUE;
3026 case CONTROL_DMARC_FORENSIC:
3027 dmarc_enable_forensic = TRUE;
3034 int fd, af, level, optname, value;
3035 /* If we are acting on stdin, the setsockopt may fail if stdin is not
3036 a socket; we can accept that, we'll just debug-log failures anyway. */
3037 fd = fileno(smtp_in);
3038 af = ip_get_address_family(fd);
3042 debug_printf_indent("smtp input is probably not a socket [%s], not setting DSCP\n",
3046 if (dscp_lookup(p+1, af, &level, &optname, &value))
3048 if (setsockopt(fd, level, optname, &value, sizeof(value)) < 0)
3050 HDEBUG(D_acl) debug_printf_indent("failed to set input DSCP[%s]: %s\n",
3051 p+1, strerror(errno));
3055 HDEBUG(D_acl) debug_printf_indent("set input DSCP to \"%s\"\n", p+1);
3060 *log_msgptr = string_sprintf("unrecognised DSCP value in \"control=%s\"", arg);
3066 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3074 case CONTROL_CASEFUL_LOCAL_PART:
3075 deliver_localpart = addr->cc_local_part;
3078 case CONTROL_CASELOWER_LOCAL_PART:
3079 deliver_localpart = addr->lc_local_part;
3082 case CONTROL_ENFORCE_SYNC:
3083 smtp_enforce_sync = TRUE;
3086 case CONTROL_NO_ENFORCE_SYNC:
3087 smtp_enforce_sync = FALSE;
3090 #ifdef WITH_CONTENT_SCAN
3091 case CONTROL_NO_MBOX_UNSPOOL:
3092 no_mbox_unspool = TRUE;
3096 case CONTROL_NO_MULTILINE:
3097 no_multiline_responses = TRUE;
3100 case CONTROL_NO_PIPELINING:
3101 pipelining_enable = FALSE;
3104 case CONTROL_NO_DELAY_FLUSH:
3105 disable_delay_flush = TRUE;
3108 case CONTROL_NO_CALLOUT_FLUSH:
3109 disable_callout_flush = TRUE;
3112 case CONTROL_FAKEREJECT:
3113 cancel_cutthrough_connection(TRUE, US"fakereject");
3114 case CONTROL_FAKEDEFER:
3115 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
3118 const uschar *pp = p + 1;
3119 while (*pp != 0) pp++;
3120 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
3125 /* Explicitly reset to default string */
3126 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).";
3130 case CONTROL_FREEZE:
3131 deliver_freeze = TRUE;
3132 deliver_frozen_at = time(NULL);
3133 freeze_tell = freeze_tell_config; /* Reset to configured value */
3134 if (Ustrncmp(p, "/no_tell", 8) == 0)
3141 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3144 cancel_cutthrough_connection(TRUE, US"item frozen");
3147 case CONTROL_QUEUE_ONLY:
3148 queue_only_policy = TRUE;
3149 cancel_cutthrough_connection(TRUE, US"queueing forced");
3152 case CONTROL_SUBMISSION:
3153 originator_name = US"";
3154 submission_mode = TRUE;
3157 if (Ustrncmp(p, "/sender_retain", 14) == 0)
3160 active_local_sender_retain = TRUE;
3161 active_local_from_check = FALSE;
3163 else if (Ustrncmp(p, "/domain=", 8) == 0)
3165 const uschar *pp = p + 8;
3166 while (*pp != 0 && *pp != '/') pp++;
3167 submission_domain = string_copyn(p+8, pp-p-8);
3170 /* The name= option must be last, because it swallows the rest of
3172 else if (Ustrncmp(p, "/name=", 6) == 0)
3174 const uschar *pp = p + 6;
3175 while (*pp != 0) pp++;
3176 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
3177 big_buffer, big_buffer_size));
3184 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
3191 uschar * debug_tag = NULL;
3192 uschar * debug_opts = NULL;
3197 const uschar * pp = p+1;
3198 if (Ustrncmp(pp, "tag=", 4) == 0)
3200 for (pp += 4; *pp && *pp != '/';) pp++;
3201 debug_tag = string_copyn(p+5, pp-p-5);
3203 else if (Ustrncmp(pp, "opts=", 5) == 0)
3205 for (pp += 5; *pp && *pp != '/';) pp++;
3206 debug_opts = string_copyn(p+6, pp-p-6);
3208 else if (Ustrncmp(pp, "kill", 4) == 0)
3210 for (pp += 4; *pp && *pp != '/';) pp++;
3214 while (*pp && *pp != '/') pp++;
3219 debug_logging_stop();
3221 debug_logging_activate(debug_tag, debug_opts);
3225 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
3226 suppress_local_fixups = TRUE;
3229 case CONTROL_CUTTHROUGH_DELIVERY:
3230 #ifndef DISABLE_PRDR
3235 /* Too hard to think about for now. We might in future cutthrough
3236 the case where both sides handle prdr and this-node prdr acl
3238 *log_msgptr = string_sprintf("PRDR on %s reception\n", arg);
3242 *log_msgptr = US"frozen";
3243 else if (queue_only_policy)
3244 *log_msgptr = US"queue-only";
3245 else if (fake_response == FAIL)
3246 *log_msgptr = US"fakereject";
3249 if (rcpt_count == 1)
3251 cutthrough.delivery = TRUE;
3254 const uschar * pp = p+1;
3255 if (Ustrncmp(pp, "defer=", 6) == 0)
3258 if (Ustrncmp(pp, "pass", 4) == 0) cutthrough.defer_pass = TRUE;
3259 /* else if (Ustrncmp(pp, "spool") == 0) ; default */
3262 while (*pp && *pp != '/') pp++;
3268 *log_msgptr = string_sprintf("\"control=%s\" on %s item",
3274 case CONTROL_UTF8_DOWNCONVERT:
3279 message_utf8_downconvert = 1;
3280 addr->prop.utf8_downcvt = TRUE;
3281 addr->prop.utf8_downcvt_maybe = FALSE;
3287 message_utf8_downconvert = 0;
3288 addr->prop.utf8_downcvt = FALSE;
3289 addr->prop.utf8_downcvt_maybe = FALSE;
3293 if (p[1] == '-' && p[2] == '1')
3295 message_utf8_downconvert = -1;
3296 addr->prop.utf8_downcvt = FALSE;
3297 addr->prop.utf8_downcvt_maybe = TRUE;
3301 *log_msgptr = US"bad option value for control=utf8_downconvert";
3305 message_utf8_downconvert = 1;
3306 addr->prop.utf8_downcvt = TRUE;
3307 addr->prop.utf8_downcvt_maybe = FALSE;
3317 #ifdef EXPERIMENTAL_DCC
3320 /* Separate the regular expression and any optional parameters. */
3321 const uschar * list = arg;
3322 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3323 /* Run the dcc backend. */
3324 rc = dcc_process(&ss);
3325 /* Modify return code based upon the existence of options. */
3326 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)))
3327 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3328 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3333 #ifdef WITH_CONTENT_SCAN
3335 rc = mime_decode(&arg);
3341 int delay = readconf_readtime(arg, 0, FALSE);
3344 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3345 "modifier: \"%s\" is not a time value", arg);
3350 HDEBUG(D_acl) debug_printf_indent("delay modifier requests %d-second delay\n",
3355 debug_printf_indent("delay skipped in -bh checking mode\n");
3358 /* NOTE 1: Remember that we may be
3359 dealing with stdin/stdout here, in addition to TCP/IP connections.
3360 Also, delays may be specified for non-SMTP input, where smtp_out and
3361 smtp_in will be NULL. Whatever is done must work in all cases.
3363 NOTE 2: The added feature of flushing the output before a delay must
3364 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3369 if (smtp_out != NULL && !disable_delay_flush)
3372 #if !defined(NO_POLL_H) && defined (POLLRDHUP)
3378 p.fd = fileno(smtp_out);
3379 p.events = POLLRDHUP;
3382 if (poll(&p, n, delay*1000) > 0)
3383 HDEBUG(D_acl) debug_printf_indent("delay cancelled by peer close\n");
3386 /* It appears to be impossible to detect that a TCP/IP connection has
3387 gone away without reading from it. This means that we cannot shorten
3388 the delay below if the client goes away, because we cannot discover
3389 that the client has closed its end of the connection. (The connection
3390 is actually in a half-closed state, waiting for the server to close its
3391 end.) It would be nice to be able to detect this state, so that the
3392 Exim process is not held up unnecessarily. However, it seems that we
3393 can't. The poll() function does not do the right thing, and in any case
3394 it is not always available.
3397 while (delay > 0) delay = sleep(delay);
3404 #ifndef DISABLE_DKIM
3405 case ACLC_DKIM_SIGNER:
3406 if (dkim_cur_signer != NULL)
3407 rc = match_isinlist(dkim_cur_signer,
3408 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3413 case ACLC_DKIM_STATUS:
3414 rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS),
3415 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3419 #ifdef EXPERIMENTAL_DMARC
3420 case ACLC_DMARC_STATUS:
3421 if (!dmarc_has_been_checked)
3423 dmarc_has_been_checked = TRUE;
3424 /* used long way of dmarc_exim_expand_query() in case we need more
3425 * view into the process in the future. */
3426 rc = match_isinlist(dmarc_exim_expand_query(DMARC_VERIFY_STATUS),
3427 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3432 rc = verify_check_dnsbl(where, &arg, log_msgptr);
3436 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3437 addr->domain_cache, MCL_DOMAIN, TRUE, CUSS &deliver_domain_data);
3440 /* The value in tls_cipher is the full cipher name, for example,
3441 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3442 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3443 what may in practice come out of the SSL library - which at the time of
3444 writing is poorly documented. */
3446 case ACLC_ENCRYPTED:
3447 if (tls_in.cipher == NULL) rc = FAIL; else
3449 uschar *endcipher = NULL;
3450 uschar *cipher = Ustrchr(tls_in.cipher, ':');
3451 if (cipher == NULL) cipher = tls_in.cipher; else
3453 endcipher = Ustrchr(++cipher, ':');
3454 if (endcipher != NULL) *endcipher = 0;
3456 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3457 if (endcipher != NULL) *endcipher = ':';
3461 /* Use verify_check_this_host() instead of verify_check_host() so that
3462 we can pass over &host_data to catch any looked up data. Once it has been
3463 set, it retains its value so that it's still there if another ACL verb
3464 comes through here and uses the cache. However, we must put it into
3465 permanent store in case it is also expected to be used in a subsequent
3466 message in the same SMTP connection. */
3469 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3470 (sender_host_address == NULL)? US"" : sender_host_address,
3472 if (rc == DEFER) *log_msgptr = search_error_message;
3473 if (host_data) host_data = string_copy_malloc(host_data);
3476 case ACLC_LOCAL_PARTS:
3477 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3478 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3479 CUSS &deliver_localpart_data);
3482 case ACLC_LOG_REJECT_TARGET:
3486 const uschar *s = arg;
3488 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size)))
3490 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3491 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3492 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3495 logbits |= LOG_MAIN|LOG_REJECT;
3496 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3497 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3500 log_reject_target = logbits;
3507 const uschar *s = arg;
3513 if (Ustrncmp(s, "main", 4) == 0)
3514 { logbits |= LOG_MAIN; s += 4; }
3515 else if (Ustrncmp(s, "panic", 5) == 0)
3516 { logbits |= LOG_PANIC; s += 5; }
3517 else if (Ustrncmp(s, "reject", 6) == 0)
3518 { logbits |= LOG_REJECT; s += 6; }
3521 logbits = LOG_MAIN|LOG_PANIC;
3522 s = string_sprintf(":unknown log name in \"%s\" in "
3523 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3529 while (isspace(*s)) s++;
3532 if (logbits == 0) logbits = LOG_MAIN;
3533 log_write(0, logbits, "%s", string_printing(s));
3537 #ifdef WITH_CONTENT_SCAN
3538 case ACLC_MALWARE: /* Run the malware backend. */
3540 /* Separate the regular expression and any optional parameters. */
3541 const uschar * list = arg;
3542 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3544 BOOL defer_ok = FALSE;
3547 while ((opt = string_nextinlist(&list, &sep, NULL, 0)))
3548 if (strcmpic(opt, US"defer_ok") == 0)
3550 else if ( strncmpic(opt, US"tmo=", 4) == 0
3551 && (timeout = readconf_readtime(opt+4, '\0', FALSE)) < 0
3554 *log_msgptr = string_sprintf("bad timeout value in '%s'", opt);
3558 rc = malware(ss, timeout);
3559 if (rc == DEFER && defer_ok)
3560 rc = FAIL; /* FAIL so that the message is passed to the next ACL */
3564 case ACLC_MIME_REGEX:
3565 rc = mime_regex(&arg);
3570 queue_name = string_copy_malloc(arg);
3573 case ACLC_RATELIMIT:
3574 rc = acl_ratelimit(arg, where, log_msgptr);
3577 case ACLC_RECIPIENTS:
3578 rc = match_address_list(CUS addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3579 CUSS &recipient_data);
3582 #ifdef WITH_CONTENT_SCAN
3588 case ACLC_REMOVE_HEADER:
3589 setup_remove_header(arg);
3592 case ACLC_SENDER_DOMAINS:
3595 sdomain = Ustrrchr(sender_address, '@');
3596 sdomain = sdomain ? sdomain + 1 : US"";
3597 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3598 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3603 rc = match_address_list(CUS sender_address, TRUE, TRUE, &arg,
3604 sender_address_cache, -1, 0, CUSS &sender_data);
3607 /* Connection variables must persist forever */
3611 int old_pool = store_pool;
3612 if ( cb->u.varname[0] == 'c'
3613 #ifndef DISABLE_EVENT
3614 || event_name /* An event is being delivered */
3617 store_pool = POOL_PERM;
3618 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3619 store_pool = old_pool;
3623 #ifdef WITH_CONTENT_SCAN
3626 /* Separate the regular expression and any optional parameters. */
3627 const uschar * list = arg;
3628 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
3629 /* Run the spam backend. */
3630 rc = spam(CUSS &ss);
3631 /* Modify return code based upon the existence of options. */
3632 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
3634 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3636 /* FAIL so that the message is passed to the next ACL */
3644 #ifdef EXPERIMENTAL_SPF
3646 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3648 case ACLC_SPF_GUESS:
3649 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3654 rc = acl_udpsend(arg, log_msgptr);
3657 /* If the verb is WARN, discard any user message from verification, because
3658 such messages are SMTP responses, not header additions. The latter come
3659 only from explicit "message" modifiers. However, put the user message into
3660 $acl_verify_message so it can be used in subsequent conditions or modifiers
3661 (until something changes it). */
3664 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3666 acl_verify_message = *user_msgptr;
3667 if (verb == ACL_WARN) *user_msgptr = NULL;
3671 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3672 "condition %d", cb->type);
3676 /* If a condition was negated, invert OK/FAIL. */
3678 if (!conditions[cb->type].is_modifier && cb->u.negated)
3679 if (rc == OK) rc = FAIL;
3680 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3682 if (rc != OK) break; /* Conditions loop */
3686 /* If the result is the one for which "message" and/or "log_message" are used,
3687 handle the values of these modifiers. If there isn't a log message set, we make
3688 it the same as the user message.
3690 "message" is a user message that will be included in an SMTP response. Unless
3691 it is empty, it overrides any previously set user message.
3693 "log_message" is a non-user message, and it adds to any existing non-user
3694 message that is already set.
3696 Most verbs have but a single return for which the messages are relevant, but
3697 for "discard", it's useful to have the log message both when it succeeds and
3698 when it fails. For "accept", the message is used in the OK case if there is no
3699 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3702 if (*epp && rc == OK) user_message = NULL;
3704 if (((1<<rc) & msgcond[verb]) != 0)
3707 uschar *old_user_msgptr = *user_msgptr;
3708 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3710 /* If the verb is "warn", messages generated by conditions (verification or
3711 nested ACLs) are always discarded. This also happens for acceptance verbs
3712 when they actually do accept. Only messages specified at this level are used.
3713 However, the value of an existing message is available in $acl_verify_message
3714 during expansions. */
3716 if (verb == ACL_WARN ||
3717 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3718 *log_msgptr = *user_msgptr = NULL;
3720 if (user_message != NULL)
3722 acl_verify_message = old_user_msgptr;
3723 expmessage = expand_string(user_message);
3724 if (expmessage == NULL)
3726 if (!expand_string_forcedfail)
3727 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3728 user_message, expand_string_message);
3730 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3733 if (log_message != NULL)
3735 acl_verify_message = old_log_msgptr;
3736 expmessage = expand_string(log_message);
3737 if (expmessage == NULL)
3739 if (!expand_string_forcedfail)
3740 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3741 log_message, expand_string_message);
3743 else if (expmessage[0] != 0)
3745 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3746 string_sprintf("%s: %s", expmessage, *log_msgptr);
3750 /* If no log message, default it to the user message */
3752 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3755 acl_verify_message = NULL;
3763 /*************************************************
3764 * Get line from a literal ACL *
3765 *************************************************/
3767 /* This function is passed to acl_read() in order to extract individual lines
3768 of a literal ACL, which we access via static pointers. We can destroy the
3769 contents because this is called only once (the compiled ACL is remembered).
3771 This code is intended to treat the data in the same way as lines in the main
3772 Exim configuration file. That is:
3774 . Leading spaces are ignored.
3776 . A \ at the end of a line is a continuation - trailing spaces after the \
3777 are permitted (this is because I don't believe in making invisible things
3778 significant). Leading spaces on the continued part of a line are ignored.
3780 . Physical lines starting (significantly) with # are totally ignored, and
3781 may appear within a sequence of backslash-continued lines.
3783 . Blank lines are ignored, but will end a sequence of continuations.
3786 Returns: a pointer to the next line
3790 static uschar *acl_text; /* Current pointer in the text */
3791 static uschar *acl_text_end; /* Points one past the terminating '0' */
3799 /* This loop handles leading blank lines and comments. */
3803 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3804 if (*acl_text == 0) return NULL; /* No more data */
3805 yield = acl_text; /* Potential data line */
3807 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3809 /* If we hit the end before a newline, we have the whole logical line. If
3810 it's a comment, there's no more data to be given. Otherwise, yield it. */
3812 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3814 /* After reaching a newline, end this loop if the physical line does not
3815 start with '#'. If it does, it's a comment, and the loop continues. */
3817 if (*yield != '#') break;
3820 /* This loop handles continuations. We know we have some real data, ending in
3821 newline. See if there is a continuation marker at the end (ignoring trailing
3822 white space). We know that *yield is not white space, so no need to test for
3823 cont > yield in the backwards scanning loop. */
3828 for (cont = acl_text - 1; isspace(*cont); cont--);
3830 /* If no continuation follows, we are done. Mark the end of the line and
3839 /* We have encountered a continuation. Skip over whitespace at the start of
3840 the next line, and indeed the whole of the next line or lines if they are
3845 while (*(++acl_text) == ' ' || *acl_text == '\t');
3846 if (*acl_text != '#') break;
3847 while (*(++acl_text) != 0 && *acl_text != '\n');
3850 /* We have the start of a continuation line. Move all the rest of the data
3851 to join onto the previous line, and then find its end. If the end is not a
3852 newline, we are done. Otherwise loop to look for another continuation. */
3854 memmove(cont, acl_text, acl_text_end - acl_text);
3855 acl_text_end -= acl_text - cont;
3857 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3858 if (*acl_text == 0) return yield;
3861 /* Control does not reach here */
3868 /*************************************************
3869 * Check access using an ACL *
3870 *************************************************/
3872 /* This function is called from address_check. It may recurse via
3873 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3874 passed as a string which is expanded. A forced failure implies no access check
3875 is required. If the result is a single word, it is taken as the name of an ACL
3876 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3877 text, complete with newlines, and parsed as such. In both cases, the ACL check
3878 is then run. This function uses an auxiliary function for acl_read() to call
3879 for reading individual lines of a literal ACL. This is acl_getline(), which
3880 appears immediately above.
3883 where where called from
3884 addr address item when called from RCPT; otherwise NULL
3885 s the input string; NULL is the same as an empty ACL => DENY
3886 user_msgptr where to put a user error (for SMTP response)
3887 log_msgptr where to put a logging message (not for SMTP response)
3889 Returns: OK access is granted
3890 DISCARD access is apparently granted...
3891 FAIL access is denied
3892 FAIL_DROP access is denied; drop the connection
3893 DEFER can't tell at the moment
3898 acl_check_internal(int where, address_item *addr, uschar *s,
3899 uschar **user_msgptr, uschar **log_msgptr)
3902 acl_block *acl = NULL;
3903 uschar *acl_name = US"inline ACL";
3906 /* Catch configuration loops */
3910 *log_msgptr = US"ACL nested too deep: possible loop";
3916 HDEBUG(D_acl) debug_printf_indent("ACL is NULL: implicit DENY\n");
3920 /* At top level, we expand the incoming string. At lower levels, it has already
3921 been expanded as part of condition processing. */
3925 if (!(ss = expand_string(s)))
3927 if (expand_string_forcedfail) return OK;
3928 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3929 expand_string_message);
3935 while (isspace(*ss))ss++;
3937 /* If we can't find a named ACL, the default is to parse it as an inline one.
3938 (Unless it begins with a slash; non-existent files give rise to an error.) */
3942 /* Handle the case of a string that does not contain any spaces. Look for a
3943 named ACL among those read from the configuration, or a previously read file.
3944 It is possible that the pointer to the ACL is NULL if the configuration
3945 contains a name with no data. If not found, and the text begins with '/',
3946 read an ACL from a file, and save it so it can be re-used. */
3948 if (Ustrchr(ss, ' ') == NULL)
3950 tree_node *t = tree_search(acl_anchor, ss);
3953 acl = (acl_block *)(t->data.ptr);
3956 HDEBUG(D_acl) debug_printf_indent("ACL \"%s\" is empty: implicit DENY\n", ss);
3959 acl_name = string_sprintf("ACL \"%s\"", ss);
3960 HDEBUG(D_acl) debug_printf_indent("using ACL \"%s\"\n", ss);
3963 else if (*ss == '/')
3965 struct stat statbuf;
3966 fd = Uopen(ss, O_RDONLY, 0);
3969 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3974 if (fstat(fd, &statbuf) != 0)
3976 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3981 acl_text = store_get(statbuf.st_size + 1);
3982 acl_text_end = acl_text + statbuf.st_size + 1;
3984 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3986 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3987 ss, strerror(errno));
3990 acl_text[statbuf.st_size] = 0;
3993 acl_name = string_sprintf("ACL \"%s\"", ss);
3994 HDEBUG(D_acl) debug_printf_indent("read ACL from file %s\n", ss);
3998 /* Parse an ACL that is still in text form. If it came from a file, remember it
3999 in the ACL tree, having read it into the POOL_PERM store pool so that it
4000 persists between multiple messages. */
4004 int old_pool = store_pool;
4005 if (fd >= 0) store_pool = POOL_PERM;
4006 acl = acl_read(acl_getline, log_msgptr);
4007 store_pool = old_pool;
4008 if (acl == NULL && *log_msgptr != NULL) return ERROR;
4011 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
4012 Ustrcpy(t->name, ss);
4014 (void)tree_insertnode(&acl_anchor, t);
4018 /* Now we have an ACL to use. It's possible it may be NULL. */
4023 int basic_errno = 0;
4024 BOOL endpass_seen = FALSE;
4025 BOOL acl_quit_check = acl_level == 0
4026 && (where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT);
4028 *log_msgptr = *user_msgptr = NULL;
4029 acl_temp_details = FALSE;
4031 HDEBUG(D_acl) debug_printf_indent("processing \"%s\"\n", verbs[acl->verb]);
4033 /* Clear out any search error message from a previous check before testing
4036 search_error_message = NULL;
4037 cond = acl_check_condition(acl->verb, acl->condition, where, addr, acl_level,
4038 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
4040 /* Handle special returns: DEFER causes a return except on a WARN verb;
4041 ERROR always causes a return. */
4046 HDEBUG(D_acl) debug_printf_indent("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
4047 if (basic_errno != ERRNO_CALLOUTDEFER)
4049 if (search_error_message != NULL && *search_error_message != 0)
4050 *log_msgptr = search_error_message;
4051 if (smtp_return_error_details) acl_temp_details = TRUE;
4055 acl_temp_details = TRUE;
4057 if (acl->verb != ACL_WARN) return DEFER;
4060 default: /* Paranoia */
4062 HDEBUG(D_acl) debug_printf_indent("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
4066 HDEBUG(D_acl) debug_printf_indent("%s: condition test succeeded in %s\n",
4067 verbs[acl->verb], acl_name);
4071 HDEBUG(D_acl) debug_printf_indent("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
4074 /* DISCARD and DROP can happen only from a nested ACL condition, and
4075 DISCARD can happen only for an "accept" or "discard" verb. */
4078 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"discard\" in %s\n",
4079 verbs[acl->verb], acl_name);
4083 HDEBUG(D_acl) debug_printf_indent("%s: condition test yielded \"drop\" in %s\n",
4084 verbs[acl->verb], acl_name);
4088 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
4089 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
4090 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
4095 if (cond == OK || cond == DISCARD)
4097 HDEBUG(D_acl) debug_printf_indent("end of %s: ACCEPT\n", acl_name);
4102 HDEBUG(D_acl) debug_printf_indent("accept: endpass encountered - denying access\n");
4110 HDEBUG(D_acl) debug_printf_indent("end of %s: DEFER\n", acl_name);
4111 if (acl_quit_check) goto badquit;
4112 acl_temp_details = TRUE;
4120 HDEBUG(D_acl) debug_printf_indent("end of %s: DENY\n", acl_name);
4121 if (acl_quit_check) goto badquit;
4127 if (cond == OK || cond == DISCARD)
4129 HDEBUG(D_acl) debug_printf_indent("end of %s: DISCARD\n", acl_name);
4130 if (acl_quit_check) goto badquit;
4135 HDEBUG(D_acl) debug_printf_indent("discard: endpass encountered - denying access\n");
4143 HDEBUG(D_acl) debug_printf_indent("end of %s: DROP\n", acl_name);
4144 if (acl_quit_check) goto badquit;
4152 HDEBUG(D_acl) debug_printf_indent("end of %s: not OK\n", acl_name);
4153 if (acl_quit_check) goto badquit;
4160 acl_warn(where, *user_msgptr, *log_msgptr);
4161 else if (cond == DEFER && LOGGING(acl_warn_skipped))
4162 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
4163 "condition test deferred%s%s", host_and_ident(TRUE),
4164 (*log_msgptr == NULL)? US"" : US": ",
4165 (*log_msgptr == NULL)? US"" : *log_msgptr);
4166 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
4170 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
4175 /* Pass to the next ACL item */
4180 /* We have reached the end of the ACL. This is an implicit DENY. */
4182 HDEBUG(D_acl) debug_printf_indent("end of %s: implicit DENY\n", acl_name);
4186 *log_msgptr = string_sprintf("QUIT or not-QUIT toplevel ACL may not fail "
4187 "('%s' verb used incorrectly)", verbs[acl->verb]);
4194 /* Same args as acl_check_internal() above, but the string s is
4195 the name of an ACL followed optionally by up to 9 space-separated arguments.
4196 The name and args are separately expanded. Args go into $acl_arg globals. */
4198 acl_check_wargs(int where, address_item *addr, const uschar *s,
4199 uschar **user_msgptr, uschar **log_msgptr)
4202 uschar * tmp_arg[9]; /* must match acl_arg[] */
4203 uschar * sav_arg[9]; /* must match acl_arg[] */
4209 if (!(tmp = string_dequote(&s)) || !(name = expand_string(tmp)))
4212 for (i = 0; i < 9; i++)
4214 while (*s && isspace(*s)) s++;
4216 if (!(tmp = string_dequote(&s)) || !(tmp_arg[i] = expand_string(tmp)))
4223 sav_narg = acl_narg;
4225 for (i = 0; i < acl_narg; i++)
4227 sav_arg[i] = acl_arg[i];
4228 acl_arg[i] = tmp_arg[i];
4232 sav_arg[i] = acl_arg[i];
4233 acl_arg[i++] = NULL;
4237 ret = acl_check_internal(where, addr, name, user_msgptr, log_msgptr);
4240 acl_narg = sav_narg;
4241 for (i = 0; i < 9; i++) acl_arg[i] = sav_arg[i];
4245 if (expand_string_forcedfail) return ERROR;
4246 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
4247 tmp, expand_string_message);
4248 return search_find_defer?DEFER:ERROR;
4253 /*************************************************
4254 * Check access using an ACL *
4255 *************************************************/
4257 /* Alternate interface for ACL, used by expansions */
4259 acl_eval(int where, uschar *s, uschar **user_msgptr, uschar **log_msgptr)
4262 address_item *addr = NULL;
4265 *user_msgptr = *log_msgptr = NULL;
4266 sender_verified_failed = NULL;
4267 ratelimiters_cmd = NULL;
4268 log_reject_target = LOG_MAIN|LOG_REJECT;
4270 if (where == ACL_WHERE_RCPT)
4272 adb = address_defaults;
4274 addr->address = expand_string(US"$local_part@$domain");
4275 addr->domain = deliver_domain;
4276 addr->local_part = deliver_localpart;
4277 addr->cc_local_part = deliver_localpart;
4278 addr->lc_local_part = deliver_localpart;
4282 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4289 /* This is the external interface for ACL checks. It sets up an address and the
4290 expansions for $domain and $local_part when called after RCPT, then calls
4291 acl_check_internal() to do the actual work.
4294 where ACL_WHERE_xxxx indicating where called from
4295 recipient RCPT address for RCPT check, else NULL
4296 s the input string; NULL is the same as an empty ACL => DENY
4297 user_msgptr where to put a user error (for SMTP response)
4298 log_msgptr where to put a logging message (not for SMTP response)
4300 Returns: OK access is granted by an ACCEPT verb
4301 DISCARD access is granted by a DISCARD verb
4302 FAIL access is denied
4303 FAIL_DROP access is denied; drop the connection
4304 DEFER can't tell at the moment
4307 int acl_where = ACL_WHERE_UNKNOWN;
4310 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
4311 uschar **log_msgptr)
4315 address_item *addr = NULL;
4317 *user_msgptr = *log_msgptr = NULL;
4318 sender_verified_failed = NULL;
4319 ratelimiters_cmd = NULL;
4320 log_reject_target = LOG_MAIN|LOG_REJECT;
4322 #ifndef DISABLE_PRDR
4323 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY || where==ACL_WHERE_PRDR)
4325 if (where==ACL_WHERE_RCPT || where==ACL_WHERE_VRFY)
4328 adb = address_defaults;
4330 addr->address = recipient;
4331 if (deliver_split_address(addr) == DEFER)
4333 *log_msgptr = US"defer in percent_hack_domains check";
4337 if ((addr->prop.utf8_msg = message_smtputf8))
4339 addr->prop.utf8_downcvt = message_utf8_downconvert == 1;
4340 addr->prop.utf8_downcvt_maybe = message_utf8_downconvert == -1;
4343 deliver_domain = addr->domain;
4344 deliver_localpart = addr->local_part;
4349 rc = acl_check_internal(where, addr, s, user_msgptr, log_msgptr);
4351 acl_where = ACL_WHERE_UNKNOWN;
4353 /* Cutthrough - if requested,
4354 and WHERE_RCPT and not yet opened conn as result of recipient-verify,
4355 and rcpt acl returned accept,
4356 and first recipient (cancel on any subsequents)
4357 open one now and run it up to RCPT acceptance.
4358 A failed verify should cancel cutthrough request,
4359 and will pass the fail to the originator.
4360 Initial implementation: dual-write to spool.
4361 Assume the rxd datastream is now being copied byte-for-byte to an open cutthrough connection.
4363 Cease cutthrough copy on rxd final dot; do not send one.
4365 On a data acl, if not accept and a cutthrough conn is open, hard-close it (no SMTP niceness).
4367 On data acl accept, terminate the dataphase on an open cutthrough conn. If accepted or
4368 perm-rejected, reflect that to the original sender - and dump the spooled copy.
4369 If temp-reject, close the conn (and keep the spooled copy).
4370 If conn-failure, no action (and keep the spooled copy).
4374 case ACL_WHERE_RCPT:
4375 #ifndef DISABLE_PRDR
4376 case ACL_WHERE_PRDR:
4379 if (host_checking_callout) /* -bhc mode */
4380 cancel_cutthrough_connection(TRUE, US"host-checking mode");
4383 && cutthrough.delivery
4384 && rcpt_count > cutthrough.nrcpt
4385 && (rc = open_cutthrough_connection(addr)) == DEFER
4387 if (cutthrough.defer_pass)
4389 uschar * s = addr->message;
4390 /* Horrid kludge to recover target's SMTP message */
4392 do --s; while (!isdigit(*s));
4393 if (*--s && isdigit(*s) && *--s && isdigit(*s)) *user_msgptr = s;
4394 acl_temp_details = TRUE;
4398 HDEBUG(D_acl) debug_printf_indent("cutthrough defer; will spool\n");
4403 case ACL_WHERE_PREDATA:
4405 cutthrough_predata();
4407 cancel_cutthrough_connection(TRUE, US"predata acl not ok");
4410 case ACL_WHERE_QUIT:
4411 case ACL_WHERE_NOTQUIT:
4412 /* Drop cutthrough conns, and drop heldopen verify conns if
4413 the previous was not DATA */
4415 uschar prev = smtp_connection_had[smtp_ch_index-2];
4416 BOOL dropverify = !(prev == SCH_DATA || prev == SCH_BDAT);
4418 cancel_cutthrough_connection(dropverify, US"quit or conndrop");
4426 deliver_domain = deliver_localpart = deliver_address_data =
4427 sender_address_data = NULL;
4429 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
4430 ACL, which is really in the middle of an SMTP command. */
4434 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
4436 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
4437 "ACL", acl_wherenames[where]);
4443 /* A DROP response is not permitted from MAILAUTH */
4445 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
4447 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
4448 "ACL", acl_wherenames[where]);
4452 /* Before giving a response, take a look at the length of any user message, and
4453 split it up into multiple lines if possible. */
4455 *user_msgptr = string_split_message(*user_msgptr);
4456 if (fake_response != OK)
4457 fake_response_text = string_split_message(fake_response_text);
4463 /*************************************************
4464 * Create ACL variable *
4465 *************************************************/
4467 /* Create an ACL variable or reuse an existing one. ACL variables are in a
4468 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
4471 name pointer to the variable's name, starting with c or m
4473 Returns the pointer to variable's tree node
4477 acl_var_create(uschar * name)
4479 tree_node * node, ** root = name[0] == 'c' ? &acl_var_c : &acl_var_m;
4480 if (!(node = tree_search(*root, name)))
4482 node = store_get(sizeof(tree_node) + Ustrlen(name));
4483 Ustrcpy(node->name, name);
4484 (void)tree_insertnode(root, node);
4486 node->data.ptr = NULL;
4492 /*************************************************
4493 * Write an ACL variable in spool format *
4494 *************************************************/
4496 /* This function is used as a callback for tree_walk when writing variables to
4497 the spool file. To retain spool file compatibility, what is written is -aclc or
4498 -aclm followed by the rest of the name and the data length, space separated,
4499 then the value itself, starting on a new line, and terminated by an additional
4500 newline. When we had only numbered ACL variables, the first line might look
4501 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
4505 name of the variable
4506 value of the variable
4507 ctx FILE pointer (as a void pointer)
4513 acl_var_write(uschar *name, uschar *value, void *ctx)
4515 FILE *f = (FILE *)ctx;
4516 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);