1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2012 */
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 { US"accept", US"defer", US"deny", US"discard", US"drop", US"require",
28 /* For each verb, the conditions for which "message" or "log_message" are used
29 are held as a bitmap. This is to avoid expanding the strings unnecessarily. For
30 "accept", the FAIL case is used only after "endpass", but that is selected in
33 static int msgcond[] = {
34 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* accept */
37 (1<<OK) | (1<<FAIL) | (1<<FAIL_DROP), /* discard */
39 (1<<FAIL) | (1<<FAIL_DROP), /* require */
43 /* ACL condition and modifier codes - keep in step with the table that
44 follows, and the cond_expand_at_top and uschar cond_modifiers tables lower
50 #ifdef EXPERIMENTAL_BRIGHTMAIL
56 #ifdef EXPERIMENTAL_DCC
59 #ifdef WITH_CONTENT_SCAN
63 #ifdef WITH_OLD_DEMIME
77 ACLC_LOG_REJECT_TARGET,
79 #ifdef WITH_CONTENT_SCAN
83 #ifdef WITH_CONTENT_SCAN
88 #ifdef WITH_CONTENT_SCAN
94 #ifdef WITH_CONTENT_SCAN
97 #ifdef EXPERIMENTAL_SPF
103 /* ACL conditions/modifiers: "delay", "control", "continue", "endpass",
104 "message", "log_message", "log_reject_target", "logwrite", and "set" are
105 modifiers that look like conditions but always return TRUE. They are used for
106 their side effects. */
108 static uschar *conditions[] = {
112 #ifdef EXPERIMENTAL_BRIGHTMAIL
118 #ifdef EXPERIMENTAL_DCC
121 #ifdef WITH_CONTENT_SCAN
125 #ifdef WITH_OLD_DEMIME
139 US"log_reject_target",
141 #ifdef WITH_CONTENT_SCAN
145 #ifdef WITH_CONTENT_SCAN
150 #ifdef WITH_CONTENT_SCAN
153 US"sender_domains", US"senders", US"set",
154 #ifdef WITH_CONTENT_SCAN
157 #ifdef EXPERIMENTAL_SPF
164 /* Return values from decode_control(); keep in step with the table of names
168 CONTROL_AUTH_UNADVERTISED,
169 #ifdef EXPERIMENTAL_BRIGHTMAIL
177 CONTROL_CASEFUL_LOCAL_PART,
178 CONTROL_CASELOWER_LOCAL_PART,
179 CONTROL_ENFORCE_SYNC,
180 CONTROL_NO_ENFORCE_SYNC,
184 CONTROL_SUPPRESS_LOCAL_FIXUPS,
185 #ifdef WITH_CONTENT_SCAN
186 CONTROL_NO_MBOX_UNSPOOL,
190 CONTROL_NO_MULTILINE,
191 CONTROL_NO_PIPELINING,
192 CONTROL_NO_DELAY_FLUSH,
193 CONTROL_NO_CALLOUT_FLUSH
196 /* ACL control names; keep in step with the table above! This list is used for
197 turning ids into names. The actual list of recognized names is in the variable
198 control_def controls_list[] below. The fact that there are two lists is a mess
199 and should be tidied up. */
201 static uschar *controls[] = {
202 US"allow_auth_unadvertised",
203 #ifdef EXPERIMENTAL_BRIGHTMAIL
208 US"dkim_disable_verify",
211 US"caseful_local_part",
212 US"caselower_local_part",
218 US"suppress_local_fixups",
219 #ifdef WITH_CONTENT_SCAN
224 US"no_multiline_responses",
230 /* Flags to indicate for which conditions/modifiers a string expansion is done
231 at the outer level. In the other cases, expansion already occurs in the
232 checking functions. */
234 static uschar cond_expand_at_top[] = {
236 TRUE, /* add_header */
237 FALSE, /* authenticated */
238 #ifdef EXPERIMENTAL_BRIGHTMAIL
239 TRUE, /* bmi_optin */
241 TRUE, /* condition */
244 #ifdef EXPERIMENTAL_DCC
247 #ifdef WITH_CONTENT_SCAN
251 #ifdef WITH_OLD_DEMIME
255 TRUE, /* dkim_signers */
256 TRUE, /* dkim_status */
260 FALSE, /* encrypted */
263 FALSE, /* local_parts */
264 TRUE, /* log_message */
265 TRUE, /* log_reject_target */
267 #ifdef WITH_CONTENT_SCAN
271 #ifdef WITH_CONTENT_SCAN
272 TRUE, /* mime_regex */
274 TRUE, /* ratelimit */
275 FALSE, /* recipients */
276 #ifdef WITH_CONTENT_SCAN
279 FALSE, /* sender_domains */
282 #ifdef WITH_CONTENT_SCAN
285 #ifdef EXPERIMENTAL_SPF
287 TRUE, /* spf_guess */
292 /* Flags to identify the modifiers */
294 static uschar cond_modifiers[] = {
296 TRUE, /* add_header */
297 FALSE, /* authenticated */
298 #ifdef EXPERIMENTAL_BRIGHTMAIL
299 TRUE, /* bmi_optin */
301 FALSE, /* condition */
304 #ifdef EXPERIMENTAL_DCC
307 #ifdef WITH_CONTENT_SCAN
311 #ifdef WITH_OLD_DEMIME
315 FALSE, /* dkim_signers */
316 FALSE, /* dkim_status */
318 FALSE, /* dnslists */
320 FALSE, /* encrypted */
323 FALSE, /* local_parts */
324 TRUE, /* log_message */
325 TRUE, /* log_reject_target */
327 #ifdef WITH_CONTENT_SCAN
331 #ifdef WITH_CONTENT_SCAN
332 FALSE, /* mime_regex */
334 FALSE, /* ratelimit */
335 FALSE, /* recipients */
336 #ifdef WITH_CONTENT_SCAN
339 FALSE, /* sender_domains */
342 #ifdef WITH_CONTENT_SCAN
345 #ifdef EXPERIMENTAL_SPF
347 FALSE, /* spf_guess */
352 /* Bit map vector of which conditions and modifiers are not allowed at certain
353 times. For each condition and modifier, there's a bitmap of dis-allowed times.
354 For some, it is easier to specify the negation of a small number of allowed
357 static unsigned int cond_forbids[] = {
361 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* add_header */
362 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
363 (1<<ACL_WHERE_MIME)|(1<<ACL_WHERE_NOTSMTP)|
365 (1<<ACL_WHERE_NOTSMTP_START)),
367 (1<<ACL_WHERE_NOTSMTP)| /* authenticated */
368 (1<<ACL_WHERE_NOTSMTP_START)|
369 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO),
371 #ifdef EXPERIMENTAL_BRIGHTMAIL
372 (1<<ACL_WHERE_AUTH)| /* bmi_optin */
373 (1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)|
374 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_MIME)|
375 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
376 (1<<ACL_WHERE_MAILAUTH)|
377 (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_STARTTLS)|
378 (1<<ACL_WHERE_VRFY)|(1<<ACL_WHERE_PREDATA)|
379 (1<<ACL_WHERE_NOTSMTP_START),
386 /* Certain types of control are always allowed, so we let it through
387 always and check in the control processing itself. */
391 #ifdef EXPERIMENTAL_DCC
393 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* dcc */
396 #ifdef WITH_CONTENT_SCAN
398 ~(1<<ACL_WHERE_MIME), /* decode */
401 (1<<ACL_WHERE_NOTQUIT), /* delay */
403 #ifdef WITH_OLD_DEMIME
405 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* demime */
410 ~(1<<ACL_WHERE_DKIM), /* dkim_signers */
413 ~(1<<ACL_WHERE_DKIM), /* dkim_status */
416 (1<<ACL_WHERE_NOTSMTP)| /* dnslists */
417 (1<<ACL_WHERE_NOTSMTP_START),
420 ~(1<<ACL_WHERE_RCPT), /* domains */
422 (1<<ACL_WHERE_NOTSMTP)| /* encrypted */
423 (1<<ACL_WHERE_CONNECT)|
424 (1<<ACL_WHERE_NOTSMTP_START)|
429 (1<<ACL_WHERE_NOTSMTP)| /* hosts */
430 (1<<ACL_WHERE_NOTSMTP_START),
433 ~(1<<ACL_WHERE_RCPT), /* local_parts */
437 0, /* log_reject_target */
441 #ifdef WITH_CONTENT_SCAN
443 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* malware */
448 #ifdef WITH_CONTENT_SCAN
450 ~(1<<ACL_WHERE_MIME), /* mime_regex */
456 ~(1<<ACL_WHERE_RCPT), /* recipients */
458 #ifdef WITH_CONTENT_SCAN
460 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* regex */
461 (1<<ACL_WHERE_MIME)),
464 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* sender_domains */
466 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
467 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
468 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
470 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* senders */
472 (1<<ACL_WHERE_MAILAUTH)|(1<<ACL_WHERE_QUIT)|
473 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
474 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY),
478 #ifdef WITH_CONTENT_SCAN
480 ~((1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)), /* spam */
483 #ifdef EXPERIMENTAL_SPF
484 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf */
486 (1<<ACL_WHERE_MAILAUTH)|
487 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
488 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
489 (1<<ACL_WHERE_NOTSMTP)|
490 (1<<ACL_WHERE_NOTSMTP_START),
492 (1<<ACL_WHERE_AUTH)|(1<<ACL_WHERE_CONNECT)| /* spf_guess */
494 (1<<ACL_WHERE_MAILAUTH)|
495 (1<<ACL_WHERE_ETRN)|(1<<ACL_WHERE_EXPN)|
496 (1<<ACL_WHERE_STARTTLS)|(1<<ACL_WHERE_VRFY)|
497 (1<<ACL_WHERE_NOTSMTP)|
498 (1<<ACL_WHERE_NOTSMTP_START),
501 /* Certain types of verify are always allowed, so we let it through
502 always and check in the verify function itself */
508 /* Bit map vector of which controls are not allowed at certain times. For
509 each control, there's a bitmap of dis-allowed times. For some, it is easier to
510 specify the negation of a small number of allowed times. */
512 static unsigned int control_forbids[] = {
514 ~((1<<ACL_WHERE_CONNECT)|(1<<ACL_WHERE_HELO)), /* allow_auth_unadvertised */
516 #ifdef EXPERIMENTAL_BRIGHTMAIL
523 (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP)| /* dkim_disable_verify */
524 (1<<ACL_WHERE_NOTSMTP_START),
530 ~(1<<ACL_WHERE_RCPT), /* caseful_local_part */
533 ~(1<<ACL_WHERE_RCPT), /* caselower_local_part */
535 (1<<ACL_WHERE_NOTSMTP)| /* enforce_sync */
536 (1<<ACL_WHERE_NOTSMTP_START),
538 (1<<ACL_WHERE_NOTSMTP)| /* no_enforce_sync */
539 (1<<ACL_WHERE_NOTSMTP_START),
542 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* freeze */
543 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
544 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
547 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* queue_only */
548 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
549 (1<<ACL_WHERE_NOTSMTP)|(1<<ACL_WHERE_MIME)),
552 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* submission */
553 (1<<ACL_WHERE_PREDATA)),
556 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* suppress_local_fixups */
557 (1<<ACL_WHERE_PREDATA)|
558 (1<<ACL_WHERE_NOTSMTP_START)),
560 #ifdef WITH_CONTENT_SCAN
562 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* no_mbox_unspool */
563 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
564 (1<<ACL_WHERE_MIME)),
568 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakedefer */
569 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
570 (1<<ACL_WHERE_MIME)),
573 ~((1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)| /* fakereject */
574 (1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|
575 (1<<ACL_WHERE_MIME)),
577 (1<<ACL_WHERE_NOTSMTP)| /* no_multiline */
578 (1<<ACL_WHERE_NOTSMTP_START),
580 (1<<ACL_WHERE_NOTSMTP)| /* no_pipelining */
581 (1<<ACL_WHERE_NOTSMTP_START),
583 (1<<ACL_WHERE_NOTSMTP)| /* no_delay_flush */
584 (1<<ACL_WHERE_NOTSMTP_START),
586 (1<<ACL_WHERE_NOTSMTP)| /* no_callout_flush */
587 (1<<ACL_WHERE_NOTSMTP_START)
590 /* Structure listing various control arguments, with their characteristics. */
592 typedef struct control_def {
594 int value; /* CONTROL_xxx value */
595 BOOL has_option; /* Has /option(s) following */
598 static control_def controls_list[] = {
599 { US"allow_auth_unadvertised", CONTROL_AUTH_UNADVERTISED, FALSE },
600 #ifdef EXPERIMENTAL_BRIGHTMAIL
601 { US"bmi_run", CONTROL_BMI_RUN, FALSE },
603 { US"debug", CONTROL_DEBUG, TRUE },
605 { US"dkim_disable_verify", CONTROL_DKIM_VERIFY, FALSE },
607 { US"caseful_local_part", CONTROL_CASEFUL_LOCAL_PART, FALSE },
608 { US"caselower_local_part", CONTROL_CASELOWER_LOCAL_PART, FALSE },
609 { US"enforce_sync", CONTROL_ENFORCE_SYNC, FALSE },
610 { US"freeze", CONTROL_FREEZE, TRUE },
611 { US"no_callout_flush", CONTROL_NO_CALLOUT_FLUSH, FALSE },
612 { US"no_delay_flush", CONTROL_NO_DELAY_FLUSH, FALSE },
613 { US"no_enforce_sync", CONTROL_NO_ENFORCE_SYNC, FALSE },
614 { US"no_multiline_responses", CONTROL_NO_MULTILINE, FALSE },
615 { US"no_pipelining", CONTROL_NO_PIPELINING, FALSE },
616 { US"queue_only", CONTROL_QUEUE_ONLY, FALSE },
617 #ifdef WITH_CONTENT_SCAN
618 { US"no_mbox_unspool", CONTROL_NO_MBOX_UNSPOOL, FALSE },
620 { US"fakedefer", CONTROL_FAKEDEFER, TRUE },
621 { US"fakereject", CONTROL_FAKEREJECT, TRUE },
622 { US"submission", CONTROL_SUBMISSION, TRUE },
623 { US"suppress_local_fixups", CONTROL_SUPPRESS_LOCAL_FIXUPS, FALSE }
626 /* Support data structures for Client SMTP Authorization. acl_verify_csa()
627 caches its result in a tree to avoid repeated DNS queries. The result is an
628 integer code which is used as an index into the following tables of
629 explanatory strings and verification return codes. */
631 static tree_node *csa_cache = NULL;
633 enum { CSA_UNKNOWN, CSA_OK, CSA_DEFER_SRV, CSA_DEFER_ADDR,
634 CSA_FAIL_EXPLICIT, CSA_FAIL_DOMAIN, CSA_FAIL_NOADDR, CSA_FAIL_MISMATCH };
636 /* The acl_verify_csa() return code is translated into an acl_verify() return
637 code using the following table. It is OK unless the client is definitely not
638 authorized. This is because CSA is supposed to be optional for sending sites,
639 so recipients should not be too strict about checking it - especially because
640 DNS problems are quite likely to occur. It's possible to use $csa_status in
641 further ACL conditions to distinguish ok, unknown, and defer if required, but
642 the aim is to make the usual configuration simple. */
644 static int csa_return_code[] = {
646 FAIL, FAIL, FAIL, FAIL
649 static uschar *csa_status_string[] = {
650 US"unknown", US"ok", US"defer", US"defer",
651 US"fail", US"fail", US"fail", US"fail"
654 static uschar *csa_reason_string[] = {
657 US"deferred (SRV lookup failed)",
658 US"deferred (target address lookup failed)",
659 US"failed (explicit authorization required)",
660 US"failed (host name not authorized)",
661 US"failed (no authorized addresses)",
662 US"failed (client address mismatch)"
665 /* Options for the ratelimit condition. Note that there are two variants of
666 the per_rcpt option, depending on the ACL that is used to measure the rate.
667 However any ACL must be able to look up per_rcpt rates in /noupdate mode,
668 so the two variants must have the same internal representation as well as
669 the same configuration string. */
672 RATE_PER_WHAT, RATE_PER_CLASH, RATE_PER_ADDR, RATE_PER_BYTE, RATE_PER_CMD,
673 RATE_PER_CONN, RATE_PER_MAIL, RATE_PER_RCPT, RATE_PER_ALLRCPTS
676 #define RATE_SET(var,new) \
677 (((var) == RATE_PER_WHAT) ? ((var) = RATE_##new) : ((var) = RATE_PER_CLASH))
679 static uschar *ratelimit_option_string[] = {
680 US"?", US"!", US"per_addr", US"per_byte", US"per_cmd",
681 US"per_conn", US"per_mail", US"per_rcpt", US"per_rcpt"
684 /* Enable recursion between acl_check_internal() and acl_check_condition() */
686 static int acl_check_internal(int, address_item *, uschar *, int, uschar **,
690 /*************************************************
691 * Pick out name from list *
692 *************************************************/
694 /* Use a binary chop method
701 Returns: offset in list, or -1 if not found
705 acl_checkname(uschar *name, uschar **list, int end)
711 int mid = (start + end)/2;
712 int c = Ustrcmp(name, list[mid]);
713 if (c == 0) return mid;
714 if (c < 0) end = mid; else start = mid + 1;
721 /*************************************************
722 * Read and parse one ACL *
723 *************************************************/
725 /* This function is called both from readconf in order to parse the ACLs in the
726 configuration file, and also when an ACL is encountered dynamically (e.g. as
727 the result of an expansion). It is given a function to call in order to
728 retrieve the lines of the ACL. This function handles skipping comments and
729 blank lines (where relevant).
732 func function to get next line of ACL
733 error where to put an error message
735 Returns: pointer to ACL, or NULL
736 NULL can be legal (empty ACL); in this case error will be NULL
740 acl_read(uschar *(*func)(void), uschar **error)
742 acl_block *yield = NULL;
743 acl_block **lastp = &yield;
744 acl_block *this = NULL;
745 acl_condition_block *cond;
746 acl_condition_block **condp = NULL;
751 while ((s = (*func)()) != NULL)
754 BOOL negated = FALSE;
755 uschar *saveline = s;
758 /* Conditions (but not verbs) are allowed to be negated by an initial
761 while (isspace(*s)) s++;
768 /* Read the name of a verb or a condition, or the start of a new ACL, which
769 can be started by a name, or by a macro definition. */
771 s = readconf_readname(name, sizeof(name), s);
772 if (*s == ':' || (isupper(name[0]) && *s == '=')) return yield;
774 /* If a verb is unrecognized, it may be another condition or modifier that
775 continues the previous verb. */
777 v = acl_checkname(name, verbs, sizeof(verbs)/sizeof(char *));
782 *error = string_sprintf("unknown ACL verb \"%s\" in \"%s\"", name,
794 *error = string_sprintf("malformed ACL line \"%s\"", saveline);
797 this = store_get(sizeof(acl_block));
799 lastp = &(this->next);
802 this->condition = NULL;
803 condp = &(this->condition);
804 if (*s == 0) continue; /* No condition on this line */
810 s = readconf_readname(name, sizeof(name), s); /* Condition name */
813 /* Handle a condition or modifier. */
815 c = acl_checkname(name, conditions, sizeof(conditions)/sizeof(char *));
818 *error = string_sprintf("unknown ACL condition/modifier in \"%s\"",
823 /* The modifiers may not be negated */
825 if (negated && cond_modifiers[c])
827 *error = string_sprintf("ACL error: negation is not allowed with "
828 "\"%s\"", conditions[c]);
832 /* ENDPASS may occur only with ACCEPT or DISCARD. */
834 if (c == ACLC_ENDPASS &&
835 this->verb != ACL_ACCEPT &&
836 this->verb != ACL_DISCARD)
838 *error = string_sprintf("ACL error: \"%s\" is not allowed with \"%s\"",
839 conditions[c], verbs[this->verb]);
843 cond = store_get(sizeof(acl_condition_block));
846 cond->u.negated = negated;
849 condp = &(cond->next);
851 /* The "set" modifier is different in that its argument is "name=value"
852 rather than just a value, and we can check the validity of the name, which
853 gives us a variable name to insert into the data block. The original ACL
854 variable names were acl_c0 ... acl_c9 and acl_m0 ... acl_m9. This was
855 extended to 20 of each type, but after that people successfully argued for
856 arbitrary names. In the new scheme, the names must start with acl_c or acl_m.
857 After that, we allow alphanumerics and underscores, but the first character
858 after c or m must be a digit or an underscore. This retains backwards
865 if (Ustrncmp(s, "acl_c", 5) != 0 &&
866 Ustrncmp(s, "acl_m", 5) != 0)
868 *error = string_sprintf("invalid variable name after \"set\" in ACL "
869 "modifier \"set %s\" (must start \"acl_c\" or \"acl_m\")", s);
874 if (!isdigit(*endptr) && *endptr != '_')
876 *error = string_sprintf("invalid variable name after \"set\" in ACL "
877 "modifier \"set %s\" (digit or underscore must follow acl_c or acl_m)",
882 while (*endptr != 0 && *endptr != '=' && !isspace(*endptr))
884 if (!isalnum(*endptr) && *endptr != '_')
886 *error = string_sprintf("invalid character \"%c\" in variable name "
887 "in ACL modifier \"set %s\"", *endptr, s);
893 cond->u.varname = string_copyn(s + 4, endptr - s - 4);
895 while (isspace(*s)) s++;
898 /* For "set", we are now positioned for the data. For the others, only
899 "endpass" has no data */
901 if (c != ACLC_ENDPASS)
905 *error = string_sprintf("\"=\" missing after ACL \"%s\" %s", name,
906 cond_modifiers[c]? US"modifier" : US"condition");
909 while (isspace(*s)) s++;
910 cond->arg = string_copy(s);
919 /*************************************************
920 * Set up added header line(s) *
921 *************************************************/
923 /* This function is called by the add_header modifier, and also from acl_warn()
924 to implement the now-deprecated way of adding header lines using "message" on a
925 "warn" verb. The argument is treated as a sequence of header lines which are
926 added to a chain, provided there isn't an identical one already there.
928 Argument: string of header lines
933 setup_header(uschar *hstring)
936 int hlen = Ustrlen(hstring);
938 /* An empty string does nothing; otherwise add a final newline if necessary. */
940 if (hlen <= 0) return;
941 if (hstring[hlen-1] != '\n') hstring = string_sprintf("%s\n", hstring);
943 /* Loop for multiple header lines, taking care about continuations */
945 for (p = q = hstring; *p != 0; )
948 int newtype = htype_add_bot;
949 header_line **hptr = &acl_added_headers;
951 /* Find next header line within the string */
955 q = Ustrchr(q, '\n');
956 if (*(++q) != ' ' && *q != '\t') break;
959 /* If the line starts with a colon, interpret the instruction for where to
960 add it. This temporarily sets up a new type. */
964 if (strncmpic(p, US":after_received:", 16) == 0)
966 newtype = htype_add_rec;
969 else if (strncmpic(p, US":at_start_rfc:", 14) == 0)
971 newtype = htype_add_rfc;
974 else if (strncmpic(p, US":at_start:", 10) == 0)
976 newtype = htype_add_top;
979 else if (strncmpic(p, US":at_end:", 8) == 0)
981 newtype = htype_add_bot;
984 while (*p == ' ' || *p == '\t') p++;
987 /* See if this line starts with a header name, and if not, add X-ACL-Warn:
988 to the front of it. */
990 for (s = p; s < q - 1; s++)
992 if (*s == ':' || !isgraph(*s)) break;
995 s = string_sprintf("%s%.*s", (*s == ':')? "" : "X-ACL-Warn: ", (int) (q - p), p);
998 /* See if this line has already been added */
1000 while (*hptr != NULL)
1002 if (Ustrncmp((*hptr)->text, s, hlen) == 0) break;
1003 hptr = &((*hptr)->next);
1006 /* Add if not previously present */
1010 header_line *h = store_get(sizeof(header_line));
1019 /* Advance for next header line within the string */
1028 /*************************************************
1030 *************************************************/
1032 /* This function is called when a WARN verb's conditions are true. It adds to
1033 the message's headers, and/or writes information to the log. In each case, this
1034 only happens once (per message for headers, per connection for log).
1036 ** NOTE: The header adding action using the "message" setting is historic, and
1037 its use is now deprecated. The new add_header modifier should be used instead.
1040 where ACL_WHERE_xxxx indicating which ACL this is
1041 user_message message for adding to headers
1042 log_message message for logging, if different
1048 acl_warn(int where, uschar *user_message, uschar *log_message)
1050 if (log_message != NULL && log_message != user_message)
1053 string_item *logged;
1055 text = string_sprintf("%s Warning: %s", host_and_ident(TRUE),
1056 string_printing(log_message));
1058 /* If a sender verification has failed, and the log message is "sender verify
1059 failed", add the failure message. */
1061 if (sender_verified_failed != NULL &&
1062 sender_verified_failed->message != NULL &&
1063 strcmpic(log_message, US"sender verify failed") == 0)
1064 text = string_sprintf("%s: %s", text, sender_verified_failed->message);
1066 /* Search previously logged warnings. They are kept in malloc
1067 store so they can be freed at the start of a new message. */
1069 for (logged = acl_warn_logged; logged != NULL; logged = logged->next)
1070 if (Ustrcmp(logged->text, text) == 0) break;
1074 int length = Ustrlen(text) + 1;
1075 log_write(0, LOG_MAIN, "%s", text);
1076 logged = store_malloc(sizeof(string_item) + length);
1077 logged->text = (uschar *)logged + sizeof(string_item);
1078 memcpy(logged->text, text, length);
1079 logged->next = acl_warn_logged;
1080 acl_warn_logged = logged;
1084 /* If there's no user message, we are done. */
1086 if (user_message == NULL) return;
1088 /* If this isn't a message ACL, we can't do anything with a user message.
1091 if (where > ACL_WHERE_NOTSMTP)
1093 log_write(0, LOG_MAIN|LOG_PANIC, "ACL \"warn\" with \"message\" setting "
1094 "found in a non-message (%s) ACL: cannot specify header lines here: "
1095 "message ignored", acl_wherenames[where]);
1099 /* The code for setting up header lines is now abstracted into a separate
1100 function so that it can be used for the add_header modifier as well. */
1102 setup_header(user_message);
1107 /*************************************************
1108 * Verify and check reverse DNS *
1109 *************************************************/
1111 /* Called from acl_verify() below. We look up the host name(s) of the client IP
1112 address if this has not yet been done. The host_name_lookup() function checks
1113 that one of these names resolves to an address list that contains the client IP
1114 address, so we don't actually have to do the check here.
1117 user_msgptr pointer for user message
1118 log_msgptr pointer for log message
1120 Returns: OK verification condition succeeded
1121 FAIL verification failed
1122 DEFER there was a problem verifying
1126 acl_verify_reverse(uschar **user_msgptr, uschar **log_msgptr)
1130 user_msgptr = user_msgptr; /* stop compiler warning */
1132 /* Previous success */
1134 if (sender_host_name != NULL) return OK;
1136 /* Previous failure */
1138 if (host_lookup_failed)
1140 *log_msgptr = string_sprintf("host lookup failed%s", host_lookup_msg);
1144 /* Need to do a lookup */
1147 debug_printf("looking up host name to force name/address consistency check\n");
1149 if ((rc = host_name_lookup()) != OK)
1151 *log_msgptr = (rc == DEFER)?
1152 US"host lookup deferred for reverse lookup check"
1154 string_sprintf("host lookup failed for reverse lookup check%s",
1156 return rc; /* DEFER or FAIL */
1159 host_build_sender_fullhost();
1165 /*************************************************
1166 * Check client IP address matches CSA target *
1167 *************************************************/
1169 /* Called from acl_verify_csa() below. This routine scans a section of a DNS
1170 response for address records belonging to the CSA target hostname. The section
1171 is specified by the reset argument, either RESET_ADDITIONAL or RESET_ANSWERS.
1172 If one of the addresses matches the client's IP address, then the client is
1173 authorized by CSA. If there are target IP addresses but none of them match
1174 then the client is using an unauthorized IP address. If there are no target IP
1175 addresses then the client cannot be using an authorized IP address. (This is
1176 an odd configuration - why didn't the SRV record have a weight of 1 instead?)
1179 dnsa the DNS answer block
1180 dnss a DNS scan block for us to use
1181 reset option specifing what portion to scan, as described above
1182 target the target hostname to use for matching RR names
1184 Returns: CSA_OK successfully authorized
1185 CSA_FAIL_MISMATCH addresses found but none matched
1186 CSA_FAIL_NOADDR no target addresses found
1190 acl_verify_csa_address(dns_answer *dnsa, dns_scan *dnss, int reset,
1196 BOOL target_found = FALSE;
1198 for (rr = dns_next_rr(dnsa, dnss, reset);
1200 rr = dns_next_rr(dnsa, dnss, RESET_NEXT))
1202 /* Check this is an address RR for the target hostname. */
1206 && rr->type != T_AAAA
1213 if (strcmpic(target, rr->name) != 0) continue;
1215 target_found = TRUE;
1217 /* Turn the target address RR into a list of textual IP addresses and scan
1218 the list. There may be more than one if it is an A6 RR. */
1220 for (da = dns_address_from_rr(dnsa, rr); da != NULL; da = da->next)
1222 /* If the client IP address matches the target IP address, it's good! */
1224 DEBUG(D_acl) debug_printf("CSA target address is %s\n", da->address);
1226 if (strcmpic(sender_host_address, da->address) == 0) return CSA_OK;
1230 /* If we found some target addresses but none of them matched, the client is
1231 using an unauthorized IP address, otherwise the target has no authorized IP
1234 if (target_found) return CSA_FAIL_MISMATCH;
1235 else return CSA_FAIL_NOADDR;
1240 /*************************************************
1241 * Verify Client SMTP Authorization *
1242 *************************************************/
1244 /* Called from acl_verify() below. This routine calls dns_lookup_special()
1245 to find the CSA SRV record corresponding to the domain argument, or
1246 $sender_helo_name if no argument is provided. It then checks that the
1247 client is authorized, and that its IP address corresponds to the SRV
1248 target's address by calling acl_verify_csa_address() above. The address
1249 should have been returned in the DNS response's ADDITIONAL section, but if
1250 not we perform another DNS lookup to get it.
1253 domain pointer to optional parameter following verify = csa
1255 Returns: CSA_UNKNOWN no valid CSA record found
1256 CSA_OK successfully authorized
1257 CSA_FAIL_* client is definitely not authorized
1258 CSA_DEFER_* there was a DNS problem
1262 acl_verify_csa(uschar *domain)
1266 int priority, weight, port;
1273 /* Work out the domain we are using for the CSA lookup. The default is the
1274 client's HELO domain. If the client has not said HELO, use its IP address
1275 instead. If it's a local client (exim -bs), CSA isn't applicable. */
1277 while (isspace(*domain) && *domain != '\0') ++domain;
1278 if (*domain == '\0') domain = sender_helo_name;
1279 if (domain == NULL) domain = sender_host_address;
1280 if (sender_host_address == NULL) return CSA_UNKNOWN;
1282 /* If we have an address literal, strip off the framing ready for turning it
1283 into a domain. The framing consists of matched square brackets possibly
1284 containing a keyword and a colon before the actual IP address. */
1286 if (domain[0] == '[')
1288 uschar *start = Ustrchr(domain, ':');
1289 if (start == NULL) start = domain;
1290 domain = string_copyn(start + 1, Ustrlen(start) - 2);
1293 /* Turn domains that look like bare IP addresses into domains in the reverse
1294 DNS. This code also deals with address literals and $sender_host_address. It's
1295 not quite kosher to treat bare domains such as EHLO 192.0.2.57 the same as
1296 address literals, but it's probably the most friendly thing to do. This is an
1297 extension to CSA, so we allow it to be turned off for proper conformance. */
1299 if (string_is_ip_address(domain, NULL) != 0)
1301 if (!dns_csa_use_reverse) return CSA_UNKNOWN;
1302 dns_build_reverse(domain, target);
1306 /* Find out if we've already done the CSA check for this domain. If we have,
1307 return the same result again. Otherwise build a new cached result structure
1308 for this domain. The name is filled in now, and the value is filled in when
1309 we return from this function. */
1311 t = tree_search(csa_cache, domain);
1312 if (t != NULL) return t->data.val;
1314 t = store_get_perm(sizeof(tree_node) + Ustrlen(domain));
1315 Ustrcpy(t->name, domain);
1316 (void)tree_insertnode(&csa_cache, t);
1318 /* Now we are ready to do the actual DNS lookup(s). */
1321 switch (dns_special_lookup(&dnsa, domain, T_CSA, &found))
1323 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1326 return t->data.val = CSA_DEFER_SRV;
1328 /* If we found nothing, the client's authorization is unknown. */
1332 return t->data.val = CSA_UNKNOWN;
1334 /* We got something! Go on to look at the reply in more detail. */
1340 /* Scan the reply for well-formed CSA SRV records. */
1342 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
1344 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
1346 if (rr->type != T_SRV) continue;
1348 /* Extract the numerical SRV fields (p is incremented) */
1351 GETSHORT(priority, p);
1352 GETSHORT(weight, p);
1356 debug_printf("CSA priority=%d weight=%d port=%d\n", priority, weight, port);
1358 /* Check the CSA version number */
1360 if (priority != 1) continue;
1362 /* If the domain does not have a CSA SRV record of its own (i.e. the domain
1363 found by dns_special_lookup() is a parent of the one we asked for), we check
1364 the subdomain assertions in the port field. At the moment there's only one
1365 assertion: legitimate SMTP clients are all explicitly authorized with CSA
1366 SRV records of their own. */
1368 if (found != domain)
1371 return t->data.val = CSA_FAIL_EXPLICIT;
1373 return t->data.val = CSA_UNKNOWN;
1376 /* This CSA SRV record refers directly to our domain, so we check the value
1377 in the weight field to work out the domain's authorization. 0 and 1 are
1378 unauthorized; 3 means the client is authorized but we can't check the IP
1379 address in order to authenticate it, so we treat it as unknown; values
1380 greater than 3 are undefined. */
1382 if (weight < 2) return t->data.val = CSA_FAIL_DOMAIN;
1384 if (weight > 2) continue;
1386 /* Weight == 2, which means the domain is authorized. We must check that the
1387 client's IP address is listed as one of the SRV target addresses. Save the
1388 target hostname then break to scan the additional data for its addresses. */
1390 (void)dn_expand(dnsa.answer, dnsa.answer + dnsa.answerlen, p,
1391 (DN_EXPAND_ARG4_TYPE)target, sizeof(target));
1393 DEBUG(D_acl) debug_printf("CSA target is %s\n", target);
1398 /* If we didn't break the loop then no appropriate records were found. */
1400 if (rr == NULL) return t->data.val = CSA_UNKNOWN;
1402 /* Do not check addresses if the target is ".", in accordance with RFC 2782.
1403 A target of "." indicates there are no valid addresses, so the client cannot
1404 be authorized. (This is an odd configuration because weight=2 target=. is
1405 equivalent to weight=1, but we check for it in order to keep load off the
1406 root name servers.) Note that dn_expand() turns "." into "". */
1408 if (Ustrcmp(target, "") == 0) return t->data.val = CSA_FAIL_NOADDR;
1410 /* Scan the additional section of the CSA SRV reply for addresses belonging
1411 to the target. If the name server didn't return any additional data (e.g.
1412 because it does not fully support SRV records), we need to do another lookup
1413 to obtain the target addresses; otherwise we have a definitive result. */
1415 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ADDITIONAL, target);
1416 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1418 /* The DNS lookup type corresponds to the IP version used by the client. */
1421 if (Ustrchr(sender_host_address, ':') != NULL)
1424 #endif /* HAVE_IPV6 */
1428 #if HAVE_IPV6 && defined(SUPPORT_A6)
1432 switch (dns_lookup(&dnsa, target, type, NULL))
1434 /* If something bad happened (most commonly DNS_AGAIN), defer. */
1437 return t->data.val = CSA_DEFER_ADDR;
1439 /* If the query succeeded, scan the addresses and return the result. */
1442 rc = acl_verify_csa_address(&dnsa, &dnss, RESET_ANSWERS, target);
1443 if (rc != CSA_FAIL_NOADDR) return t->data.val = rc;
1444 /* else fall through */
1446 /* If the target has no IP addresses, the client cannot have an authorized
1447 IP address. However, if the target site uses A6 records (not AAAA records)
1448 we have to do yet another lookup in order to check them. */
1453 #if HAVE_IPV6 && defined(SUPPORT_A6)
1454 if (type == T_AAAA) { type = T_A6; goto DNS_LOOKUP_AGAIN; }
1457 return t->data.val = CSA_FAIL_NOADDR;
1463 /*************************************************
1464 * Handle verification (address & other) *
1465 *************************************************/
1467 enum { VERIFY_REV_HOST_LKUP, VERIFY_CERT, VERIFY_HELO, VERIFY_CSA, VERIFY_HDR_SYNTAX,
1468 VERIFY_NOT_BLIND, VERIFY_HDR_SNDR, VERIFY_SNDR, VERIFY_RCPT
1473 unsigned where_allowed; /* bitmap */
1474 BOOL no_options; /* Never has /option(s) following */
1475 unsigned alt_opt_sep; /* >0 Non-/ option separator (custom parser) */
1477 static verify_type_t verify_type_list[] = {
1478 { US"reverse_host_lookup", VERIFY_REV_HOST_LKUP, ~0, TRUE, 0 },
1479 { US"certificate", VERIFY_CERT, ~0, TRUE, 0 },
1480 { US"helo", VERIFY_HELO, ~0, TRUE, 0 },
1481 { US"csa", VERIFY_CSA, ~0, FALSE, 0 },
1482 { US"header_syntax", VERIFY_HDR_SYNTAX, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1483 { US"not_blind", VERIFY_NOT_BLIND, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), TRUE, 0 },
1484 { US"header_sender", VERIFY_HDR_SNDR, (1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP), FALSE, 0 },
1485 { US"sender", VERIFY_SNDR, (1<<ACL_WHERE_MAIL)|(1<<ACL_WHERE_RCPT)
1486 |(1<<ACL_WHERE_PREDATA)|(1<<ACL_WHERE_DATA)|(1<<ACL_WHERE_NOTSMTP),
1488 { US"recipient", VERIFY_RCPT, (1<<ACL_WHERE_RCPT), FALSE, 0 }
1492 enum { CALLOUT_DEFER_OK, CALLOUT_NOCACHE, CALLOUT_RANDOM, CALLOUT_USE_SENDER,
1493 CALLOUT_USE_POSTMASTER, CALLOUT_POSTMASTER, CALLOUT_FULLPOSTMASTER,
1494 CALLOUT_MAILFROM, CALLOUT_POSTMASTER_MAILFROM, CALLOUT_MAXWAIT, CALLOUT_CONNECT,
1501 BOOL has_option; /* Has =option(s) following */
1502 BOOL timeval; /* Has a time value */
1504 static callout_opt_t callout_opt_list[] = {
1505 { US"defer_ok", CALLOUT_DEFER_OK, 0, FALSE, FALSE },
1506 { US"no_cache", CALLOUT_NOCACHE, vopt_callout_no_cache, FALSE, FALSE },
1507 { US"random", CALLOUT_RANDOM, vopt_callout_random, FALSE, FALSE },
1508 { US"use_sender", CALLOUT_USE_SENDER, vopt_callout_recipsender, FALSE, FALSE },
1509 { US"use_postmaster", CALLOUT_USE_POSTMASTER,vopt_callout_recippmaster, FALSE, FALSE },
1510 { US"postmaster_mailfrom",CALLOUT_POSTMASTER_MAILFROM,0, TRUE, FALSE },
1511 { US"postmaster", CALLOUT_POSTMASTER, 0, FALSE, FALSE },
1512 { US"fullpostmaster", CALLOUT_FULLPOSTMASTER,vopt_callout_fullpm, FALSE, FALSE },
1513 { US"mailfrom", CALLOUT_MAILFROM, 0, TRUE, FALSE },
1514 { US"maxwait", CALLOUT_MAXWAIT, 0, TRUE, TRUE },
1515 { US"connect", CALLOUT_CONNECT, 0, TRUE, TRUE },
1516 { NULL, CALLOUT_TIME, 0, FALSE, TRUE }
1521 /* This function implements the "verify" condition. It is called when
1522 encountered in any ACL, because some tests are almost always permitted. Some
1523 just don't make sense, and always fail (for example, an attempt to test a host
1524 lookup for a non-TCP/IP message). Others are restricted to certain ACLs.
1527 where where called from
1528 addr the recipient address that the ACL is handling, or NULL
1529 arg the argument of "verify"
1530 user_msgptr pointer for user message
1531 log_msgptr pointer for log message
1532 basic_errno where to put verify errno
1534 Returns: OK verification condition succeeded
1535 FAIL verification failed
1536 DEFER there was a problem verifying
1541 acl_verify(int where, address_item *addr, uschar *arg,
1542 uschar **user_msgptr, uschar **log_msgptr, int *basic_errno)
1546 int callout_overall = -1;
1547 int callout_connect = -1;
1548 int verify_options = 0;
1550 BOOL verify_header_sender = FALSE;
1551 BOOL defer_ok = FALSE;
1552 BOOL callout_defer_ok = FALSE;
1553 BOOL no_details = FALSE;
1554 BOOL success_on_redirect = FALSE;
1555 address_item *sender_vaddr = NULL;
1556 uschar *verify_sender_address = NULL;
1557 uschar *pm_mailfrom = NULL;
1558 uschar *se_mailfrom = NULL;
1560 /* Some of the verify items have slash-separated options; some do not. Diagnose
1561 an error if options are given for items that don't expect them.
1564 uschar *slash = Ustrchr(arg, '/');
1566 uschar *ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size);
1569 if (ss == NULL) goto BAD_VERIFY;
1571 /* Handle name/address consistency verification in a separate function. */
1573 for (vp= verify_type_list;
1574 (char *)vp < (char *)verify_type_list + sizeof(verify_type_list);
1577 if (vp->alt_opt_sep ? strncmpic(ss, vp->name, vp->alt_opt_sep) == 0
1578 : strcmpic (ss, vp->name) == 0)
1580 if ((char *)vp >= (char *)verify_type_list + sizeof(verify_type_list))
1583 if (vp->no_options && slash != NULL)
1585 *log_msgptr = string_sprintf("unexpected '/' found in \"%s\" "
1586 "(this verify item has no options)", arg);
1589 if (!(vp->where_allowed & (1<<where)))
1591 *log_msgptr = string_sprintf("cannot verify %s in ACL for %s", vp->name, acl_wherenames[where]);
1596 case VERIFY_REV_HOST_LKUP:
1597 if (sender_host_address == NULL) return OK;
1598 return acl_verify_reverse(user_msgptr, log_msgptr);
1601 /* TLS certificate verification is done at STARTTLS time; here we just
1602 test whether it was successful or not. (This is for optional verification; for
1603 mandatory verification, the connection doesn't last this long.) */
1605 if (tls_certificate_verified) return OK;
1606 *user_msgptr = US"no verified certificate";
1610 /* We can test the result of optional HELO verification that might have
1611 occurred earlier. If not, we can attempt the verification now. */
1613 if (!helo_verified && !helo_verify_failed) smtp_verify_helo();
1614 return helo_verified? OK : FAIL;
1617 /* Do Client SMTP Authorization checks in a separate function, and turn the
1618 result code into user-friendly strings. */
1620 rc = acl_verify_csa(list);
1621 *log_msgptr = *user_msgptr = string_sprintf("client SMTP authorization %s",
1622 csa_reason_string[rc]);
1623 csa_status = csa_status_string[rc];
1624 DEBUG(D_acl) debug_printf("CSA result %s\n", csa_status);
1625 return csa_return_code[rc];
1627 case VERIFY_HDR_SYNTAX:
1628 /* Check that all relevant header lines have the correct syntax. If there is
1629 a syntax error, we return details of the error to the sender if configured to
1630 send out full details. (But a "message" setting on the ACL can override, as
1633 rc = verify_check_headers(log_msgptr);
1634 if (rc != OK && smtp_return_error_details && *log_msgptr != NULL)
1635 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1638 case VERIFY_NOT_BLIND:
1639 /* Check that no recipient of this message is "blind", that is, every envelope
1640 recipient must be mentioned in either To: or Cc:. */
1642 rc = verify_check_notblind();
1645 *log_msgptr = string_sprintf("bcc recipient detected");
1646 if (smtp_return_error_details)
1647 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1651 /* The remaining verification tests check recipient and sender addresses,
1652 either from the envelope or from the header. There are a number of
1653 slash-separated options that are common to all of them. */
1655 case VERIFY_HDR_SNDR:
1656 verify_header_sender = TRUE;
1660 /* In the case of a sender, this can optionally be followed by an address to use
1661 in place of the actual sender (rare special-case requirement). */
1665 verify_sender_address = sender_address;
1668 while (isspace(*s)) s++;
1669 if (*s++ != '=') goto BAD_VERIFY;
1670 while (isspace(*s)) s++;
1671 verify_sender_address = string_copy(s);
1682 /* Remaining items are optional; they apply to sender and recipient
1683 verification, including "header sender" verification. */
1685 while ((ss = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))
1688 if (strcmpic(ss, US"defer_ok") == 0) defer_ok = TRUE;
1689 else if (strcmpic(ss, US"no_details") == 0) no_details = TRUE;
1690 else if (strcmpic(ss, US"success_on_redirect") == 0) success_on_redirect = TRUE;
1692 /* These two old options are left for backwards compatibility */
1694 else if (strcmpic(ss, US"callout_defer_ok") == 0)
1696 callout_defer_ok = TRUE;
1697 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1700 else if (strcmpic(ss, US"check_postmaster") == 0)
1703 if (callout == -1) callout = CALLOUT_TIMEOUT_DEFAULT;
1706 /* The callout option has a number of sub-options, comma separated */
1708 else if (strncmpic(ss, US"callout", 7) == 0)
1710 callout = CALLOUT_TIMEOUT_DEFAULT;
1714 while (isspace(*ss)) ss++;
1720 while (isspace(*ss)) ss++;
1722 while ((opt = string_nextinlist(&ss, &optsep, buffer, sizeof(buffer)))
1726 double period = 1.0F;
1728 for (op= callout_opt_list; op->name; op++)
1729 if (strncmpic(opt, op->name, Ustrlen(op->name)) == 0)
1732 verify_options |= op->flag;
1735 opt += Ustrlen(op->name);
1736 while (isspace(*opt)) opt++;
1739 *log_msgptr = string_sprintf("'=' expected after "
1740 "\"%s\" in ACL verify condition \"%s\"", op->name, arg);
1743 while (isspace(*opt)) opt++;
1747 period = readconf_readtime(opt, 0, FALSE);
1750 *log_msgptr = string_sprintf("bad time value in ACL condition "
1751 "\"verify %s\"", arg);
1758 case CALLOUT_DEFER_OK: callout_defer_ok = TRUE; break;
1759 case CALLOUT_POSTMASTER: pm_mailfrom = US""; break;
1760 case CALLOUT_FULLPOSTMASTER: pm_mailfrom = US""; break;
1761 case CALLOUT_MAILFROM:
1762 if (!verify_header_sender)
1764 *log_msgptr = string_sprintf("\"mailfrom\" is allowed as a "
1765 "callout option only for verify=header_sender (detected in ACL "
1766 "condition \"%s\")", arg);
1769 se_mailfrom = string_copy(opt);
1771 case CALLOUT_POSTMASTER_MAILFROM: pm_mailfrom = string_copy(opt); break;
1772 case CALLOUT_MAXWAIT: callout_overall = period; break;
1773 case CALLOUT_CONNECT: callout_connect = period; break;
1774 case CALLOUT_TIME: callout = period; break;
1780 *log_msgptr = string_sprintf("'=' expected after \"callout\" in "
1781 "ACL condition \"%s\"", arg);
1787 /* Option not recognized */
1791 *log_msgptr = string_sprintf("unknown option \"%s\" in ACL "
1792 "condition \"verify %s\"", ss, arg);
1797 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster)) ==
1798 (vopt_callout_recipsender|vopt_callout_recippmaster))
1800 *log_msgptr = US"only one of use_sender and use_postmaster can be set "
1801 "for a recipient callout";
1805 /* Handle sender-in-header verification. Default the user message to the log
1806 message if giving out verification details. */
1808 if (verify_header_sender)
1811 rc = verify_check_header_address(user_msgptr, log_msgptr, callout,
1812 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, verify_options,
1816 *basic_errno = verrno;
1817 if (smtp_return_error_details)
1819 if (*user_msgptr == NULL && *log_msgptr != NULL)
1820 *user_msgptr = string_sprintf("Rejected after DATA: %s", *log_msgptr);
1821 if (rc == DEFER) acl_temp_details = TRUE;
1826 /* Handle a sender address. The default is to verify *the* sender address, but
1827 optionally a different address can be given, for special requirements. If the
1828 address is empty, we are dealing with a bounce message that has no sender, so
1829 we cannot do any checking. If the real sender address gets rewritten during
1830 verification (e.g. DNS widening), set the flag to stop it being rewritten again
1831 during message reception.
1833 A list of verified "sender" addresses is kept to try to avoid doing to much
1834 work repetitively when there are multiple recipients in a message and they all
1835 require sender verification. However, when callouts are involved, it gets too
1836 complicated because different recipients may require different callout options.
1837 Therefore, we always do a full sender verify when any kind of callout is
1838 specified. Caching elsewhere, for instance in the DNS resolver and in the
1839 callout handling, should ensure that this is not terribly inefficient. */
1841 else if (verify_sender_address != NULL)
1843 if ((verify_options & (vopt_callout_recipsender|vopt_callout_recippmaster))
1846 *log_msgptr = US"use_sender or use_postmaster cannot be used for a "
1847 "sender verify callout";
1851 sender_vaddr = verify_checked_sender(verify_sender_address);
1852 if (sender_vaddr != NULL && /* Previously checked */
1853 callout <= 0) /* No callout needed this time */
1855 /* If the "routed" flag is set, it means that routing worked before, so
1856 this check can give OK (the saved return code value, if set, belongs to a
1857 callout that was done previously). If the "routed" flag is not set, routing
1858 must have failed, so we use the saved return code. */
1860 if (testflag(sender_vaddr, af_verify_routed)) rc = OK; else
1862 rc = sender_vaddr->special_action;
1863 *basic_errno = sender_vaddr->basic_errno;
1865 HDEBUG(D_acl) debug_printf("using cached sender verify result\n");
1868 /* Do a new verification, and cache the result. The cache is used to avoid
1869 verifying the sender multiple times for multiple RCPTs when callouts are not
1870 specified (see comments above).
1872 The cache is also used on failure to give details in response to the first
1873 RCPT that gets bounced for this reason. However, this can be suppressed by
1874 the no_details option, which sets the flag that says "this detail has already
1875 been sent". The cache normally contains just one address, but there may be
1876 more in esoteric circumstances. */
1881 uschar *save_address_data = deliver_address_data;
1883 sender_vaddr = deliver_make_addr(verify_sender_address, TRUE);
1884 if (no_details) setflag(sender_vaddr, af_sverify_told);
1885 if (verify_sender_address[0] != 0)
1887 /* If this is the real sender address, save the unrewritten version
1888 for use later in receive. Otherwise, set a flag so that rewriting the
1889 sender in verify_address() does not update sender_address. */
1891 if (verify_sender_address == sender_address)
1892 sender_address_unrewritten = sender_address;
1894 verify_options |= vopt_fake_sender;
1896 if (success_on_redirect)
1897 verify_options |= vopt_success_on_redirect;
1899 /* The recipient, qualify, and expn options are never set in
1902 rc = verify_address(sender_vaddr, NULL, verify_options, callout,
1903 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, &routed);
1905 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1909 if (Ustrcmp(sender_vaddr->address, verify_sender_address) != 0)
1911 DEBUG(D_acl) debug_printf("sender %s verified ok as %s\n",
1912 verify_sender_address, sender_vaddr->address);
1916 DEBUG(D_acl) debug_printf("sender %s verified ok\n",
1917 verify_sender_address);
1920 else *basic_errno = sender_vaddr->basic_errno;
1922 else rc = OK; /* Null sender */
1924 /* Cache the result code */
1926 if (routed) setflag(sender_vaddr, af_verify_routed);
1927 if (callout > 0) setflag(sender_vaddr, af_verify_callout);
1928 sender_vaddr->special_action = rc;
1929 sender_vaddr->next = sender_verified_list;
1930 sender_verified_list = sender_vaddr;
1932 /* Restore the recipient address data, which might have been clobbered by
1933 the sender verification. */
1935 deliver_address_data = save_address_data;
1938 /* Put the sender address_data value into $sender_address_data */
1940 sender_address_data = sender_vaddr->p.address_data;
1943 /* A recipient address just gets a straightforward verify; again we must handle
1944 the DEFER overrides. */
1950 if (success_on_redirect)
1951 verify_options |= vopt_success_on_redirect;
1953 /* We must use a copy of the address for verification, because it might
1957 rc = verify_address(&addr2, NULL, verify_options|vopt_is_recipient, callout,
1958 callout_overall, callout_connect, se_mailfrom, pm_mailfrom, NULL);
1959 HDEBUG(D_acl) debug_printf("----------- end verify ------------\n");
1961 *basic_errno = addr2.basic_errno;
1962 *log_msgptr = addr2.message;
1963 *user_msgptr = (addr2.user_message != NULL)?
1964 addr2.user_message : addr2.message;
1966 /* Allow details for temporary error if the address is so flagged. */
1967 if (testflag((&addr2), af_pass_message)) acl_temp_details = TRUE;
1969 /* Make $address_data visible */
1970 deliver_address_data = addr2.p.address_data;
1973 /* We have a result from the relevant test. Handle defer overrides first. */
1975 if (rc == DEFER && (defer_ok ||
1976 (callout_defer_ok && *basic_errno == ERRNO_CALLOUTDEFER)))
1978 HDEBUG(D_acl) debug_printf("verify defer overridden by %s\n",
1979 defer_ok? "defer_ok" : "callout_defer_ok");
1983 /* If we've failed a sender, set up a recipient message, and point
1984 sender_verified_failed to the address item that actually failed. */
1986 if (rc != OK && verify_sender_address != NULL)
1990 *log_msgptr = *user_msgptr = US"Sender verify failed";
1992 else if (*basic_errno != ERRNO_CALLOUTDEFER)
1994 *log_msgptr = *user_msgptr = US"Could not complete sender verify";
1998 *log_msgptr = US"Could not complete sender verify callout";
1999 *user_msgptr = smtp_return_error_details? sender_vaddr->user_message :
2003 sender_verified_failed = sender_vaddr;
2006 /* Verifying an address messes up the values of $domain and $local_part,
2007 so reset them before returning if this is a RCPT ACL. */
2011 deliver_domain = addr->domain;
2012 deliver_localpart = addr->local_part;
2016 /* Syntax errors in the verify argument come here. */
2019 *log_msgptr = string_sprintf("expected \"sender[=address]\", \"recipient\", "
2020 "\"helo\", \"header_syntax\", \"header_sender\" or "
2021 "\"reverse_host_lookup\" at start of ACL condition "
2022 "\"verify %s\"", arg);
2029 /*************************************************
2030 * Check argument for control= modifier *
2031 *************************************************/
2033 /* Called from acl_check_condition() below
2036 arg the argument string for control=
2037 pptr set to point to the terminating character
2038 where which ACL we are in
2039 log_msgptr for error messages
2041 Returns: CONTROL_xxx value
2045 decode_control(uschar *arg, uschar **pptr, int where, uschar **log_msgptr)
2050 for (d = controls_list;
2051 d < controls_list + sizeof(controls_list)/sizeof(control_def);
2054 len = Ustrlen(d->name);
2055 if (Ustrncmp(d->name, arg, len) == 0) break;
2058 if (d >= controls_list + sizeof(controls_list)/sizeof(control_def) ||
2059 (arg[len] != 0 && (!d->has_option || arg[len] != '/')))
2061 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2062 return CONTROL_ERROR;
2072 /*************************************************
2073 * Return a ratelimit error *
2074 *************************************************/
2076 /* Called from acl_ratelimit() below
2079 log_msgptr for error messages
2080 format format string
2081 ... supplementary arguments
2082 ss ratelimit option name
2083 where ACL_WHERE_xxxx indicating which ACL this is
2089 ratelimit_error(uschar **log_msgptr, const char *format, ...)
2092 uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
2093 va_start(ap, format);
2094 if (!string_vformat(buffer, sizeof(buffer), format, ap))
2095 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2096 "string_sprintf expansion was longer than " SIZE_T_FMT, sizeof(buffer));
2098 *log_msgptr = string_sprintf(
2099 "error in arguments to \"ratelimit\" condition: %s", buffer);
2106 /*************************************************
2107 * Handle rate limiting *
2108 *************************************************/
2110 /* Called by acl_check_condition() below to calculate the result
2111 of the ACL ratelimit condition.
2113 Note that the return value might be slightly unexpected: if the
2114 sender's rate is above the limit then the result is OK. This is
2115 similar to the dnslists condition, and is so that you can write
2116 ACL clauses like: defer ratelimit = 15 / 1h
2119 arg the option string for ratelimit=
2120 where ACL_WHERE_xxxx indicating which ACL this is
2121 log_msgptr for error messages
2123 Returns: OK - Sender's rate is above limit
2124 FAIL - Sender's rate is below limit
2125 DEFER - Problem opening ratelimit database
2126 ERROR - Syntax error in options.
2130 acl_ratelimit(uschar *arg, int where, uschar **log_msgptr)
2132 double limit, period, count;
2135 uschar *unique = NULL;
2137 BOOL leaky = FALSE, strict = FALSE, readonly = FALSE;
2138 BOOL noupdate = FALSE, badacl = FALSE;
2139 int mode = RATE_PER_WHAT;
2141 tree_node **anchor, *t;
2142 open_db dbblock, *dbm;
2144 dbdata_ratelimit *dbd;
2145 dbdata_ratelimit_unique *dbdb;
2148 /* Parse the first two options and record their values in expansion
2149 variables. These variables allow the configuration to have informative
2150 error messages based on rate limits obtained from a table lookup. */
2152 /* First is the maximum number of messages per period / maximum burst
2153 size, which must be greater than or equal to zero. Zero is useful for
2154 rate measurement as opposed to rate limiting. */
2156 sender_rate_limit = string_nextinlist(&arg, &sep, NULL, 0);
2157 if (sender_rate_limit == NULL)
2161 limit = Ustrtod(sender_rate_limit, &ss);
2162 if (tolower(*ss) == 'k') { limit *= 1024.0; ss++; }
2163 else if (tolower(*ss) == 'm') { limit *= 1024.0*1024.0; ss++; }
2164 else if (tolower(*ss) == 'g') { limit *= 1024.0*1024.0*1024.0; ss++; }
2166 if (limit < 0.0 || *ss != '\0')
2167 return ratelimit_error(log_msgptr,
2168 "\"%s\" is not a positive number", sender_rate_limit);
2170 /* Second is the rate measurement period / exponential smoothing time
2171 constant. This must be strictly greater than zero, because zero leads to
2172 run-time division errors. */
2174 sender_rate_period = string_nextinlist(&arg, &sep, NULL, 0);
2175 if (sender_rate_period == NULL) period = -1.0;
2176 else period = readconf_readtime(sender_rate_period, 0, FALSE);
2178 return ratelimit_error(log_msgptr,
2179 "\"%s\" is not a time value", sender_rate_period);
2181 /* By default we are counting one of something, but the per_rcpt,
2182 per_byte, and count options can change this. */
2186 /* Parse the other options. */
2188 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
2191 if (strcmpic(ss, US"leaky") == 0) leaky = TRUE;
2192 else if (strcmpic(ss, US"strict") == 0) strict = TRUE;
2193 else if (strcmpic(ss, US"noupdate") == 0) noupdate = TRUE;
2194 else if (strcmpic(ss, US"readonly") == 0) readonly = TRUE;
2195 else if (strcmpic(ss, US"per_cmd") == 0) RATE_SET(mode, PER_CMD);
2196 else if (strcmpic(ss, US"per_conn") == 0)
2198 RATE_SET(mode, PER_CONN);
2199 if (where == ACL_WHERE_NOTSMTP || where == ACL_WHERE_NOTSMTP_START)
2202 else if (strcmpic(ss, US"per_mail") == 0)
2204 RATE_SET(mode, PER_MAIL);
2205 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2207 else if (strcmpic(ss, US"per_rcpt") == 0)
2209 /* If we are running in the RCPT ACL, then we'll count the recipients
2210 one by one, but if we are running when we have accumulated the whole
2211 list then we'll add them all in one batch. */
2212 if (where == ACL_WHERE_RCPT)
2213 RATE_SET(mode, PER_RCPT);
2214 else if (where >= ACL_WHERE_PREDATA && where <= ACL_WHERE_NOTSMTP)
2215 RATE_SET(mode, PER_ALLRCPTS), count = (double)recipients_count;
2216 else if (where == ACL_WHERE_MAIL || where > ACL_WHERE_NOTSMTP)
2217 RATE_SET(mode, PER_RCPT), badacl = TRUE;
2219 else if (strcmpic(ss, US"per_byte") == 0)
2221 /* If we have not yet received the message data and there was no SIZE
2222 declaration on the MAIL comand, then it's safe to just use a value of
2223 zero and let the recorded rate decay as if nothing happened. */
2224 RATE_SET(mode, PER_MAIL);
2225 if (where > ACL_WHERE_NOTSMTP) badacl = TRUE;
2226 else count = message_size < 0 ? 0.0 : (double)message_size;
2228 else if (strcmpic(ss, US"per_addr") == 0)
2230 RATE_SET(mode, PER_RCPT);
2231 if (where != ACL_WHERE_RCPT) badacl = TRUE, unique = US"*";
2232 else unique = string_sprintf("%s@%s", deliver_localpart, deliver_domain);
2234 else if (strncmpic(ss, US"count=", 6) == 0)
2237 count = Ustrtod(ss+6, &e);
2238 if (count < 0.0 || *e != '\0')
2239 return ratelimit_error(log_msgptr,
2240 "\"%s\" is not a positive number", ss);
2242 else if (strncmpic(ss, US"unique=", 7) == 0)
2243 unique = string_copy(ss + 7);
2244 else if (key == NULL)
2245 key = string_copy(ss);
2247 key = string_sprintf("%s/%s", key, ss);
2250 /* Sanity check. When the badacl flag is set the update mode must either
2251 be readonly (which is the default if it is omitted) or, for backwards
2252 compatibility, a combination of noupdate and strict or leaky. */
2254 if (mode == RATE_PER_CLASH)
2255 return ratelimit_error(log_msgptr, "conflicting per_* options");
2256 if (leaky + strict + readonly > 1)
2257 return ratelimit_error(log_msgptr, "conflicting update modes");
2258 if (badacl && (leaky || strict) && !noupdate)
2259 return ratelimit_error(log_msgptr,
2260 "\"%s\" must not have /leaky or /strict option in %s ACL",
2261 ratelimit_option_string[mode], acl_wherenames[where]);
2263 /* Set the default values of any unset options. In readonly mode we
2264 perform the rate computation without any increment so that its value
2265 decays to eventually allow over-limit senders through. */
2267 if (noupdate) readonly = TRUE, leaky = strict = FALSE;
2268 if (badacl) readonly = TRUE;
2269 if (readonly) count = 0.0;
2270 if (!strict && !readonly) leaky = TRUE;
2271 if (mode == RATE_PER_WHAT) mode = RATE_PER_MAIL;
2273 /* Create the lookup key. If there is no explicit key, use sender_host_address.
2274 If there is no sender_host_address (e.g. -bs or acl_not_smtp) then we simply
2275 omit it. The smoothing constant (sender_rate_period) and the per_xxx options
2276 are added to the key because they alter the meaning of the stored data. */
2279 key = (sender_host_address == NULL)? US"" : sender_host_address;
2281 key = string_sprintf("%s/%s/%s%s",
2283 ratelimit_option_string[mode],
2284 unique == NULL ? "" : "unique/",
2288 debug_printf("ratelimit condition count=%.0f %.1f/%s\n", count, limit, key);
2290 /* See if we have already computed the rate by looking in the relevant tree.
2291 For per-connection rate limiting, store tree nodes and dbdata in the permanent
2292 pool so that they survive across resets. In readonly mode we only remember the
2293 result for the rest of this command in case a later command changes it. After
2294 this bit of logic the code is independent of the per_* mode. */
2296 old_pool = store_pool;
2299 anchor = &ratelimiters_cmd;
2302 anchor = &ratelimiters_conn;
2303 store_pool = POOL_PERM;
2307 case RATE_PER_ALLRCPTS:
2308 anchor = &ratelimiters_mail;
2313 anchor = &ratelimiters_cmd;
2316 anchor = NULL; /* silence an "unused" complaint */
2317 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
2318 "internal ACL error: unknown ratelimit mode %d", mode);
2322 t = tree_search(*anchor, key);
2326 /* The following few lines duplicate some of the code below. */
2327 rc = (dbd->rate < limit)? FAIL : OK;
2328 store_pool = old_pool;
2329 sender_rate = string_sprintf("%.1f", dbd->rate);
2331 debug_printf("ratelimit found pre-computed rate %s\n", sender_rate);
2335 /* We aren't using a pre-computed rate, so get a previously recorded rate
2336 from the database, which will be updated and written back if required. */
2338 dbm = dbfn_open(US"ratelimit", O_RDWR, &dbblock, TRUE);
2341 store_pool = old_pool;
2343 HDEBUG(D_acl) debug_printf("ratelimit database not available\n");
2344 *log_msgptr = US"ratelimit database not available";
2347 dbdb = dbfn_read_with_length(dbm, key, &dbdb_size);
2350 gettimeofday(&tv, NULL);
2354 /* Locate the basic ratelimit block inside the DB data. */
2355 HDEBUG(D_acl) debug_printf("ratelimit found key in database\n");
2358 /* Forget the old Bloom filter if it is too old, so that we count each
2359 repeating event once per period. We don't simply clear and re-use the old
2360 filter because we want its size to change if the limit changes. Note that
2361 we keep the dbd pointer for copying the rate into the new data block. */
2363 if(unique != NULL && tv.tv_sec > dbdb->bloom_epoch + period)
2365 HDEBUG(D_acl) debug_printf("ratelimit discarding old Bloom filter\n");
2371 if(unique != NULL && dbdb_size < sizeof(*dbdb))
2373 HDEBUG(D_acl) debug_printf("ratelimit discarding undersize Bloom filter\n");
2378 /* Allocate a new data block if the database lookup failed
2379 or the Bloom filter passed its age limit. */
2385 /* No Bloom filter. This basic ratelimit block is initialized below. */
2386 HDEBUG(D_acl) debug_printf("ratelimit creating new rate data block\n");
2387 dbdb_size = sizeof(*dbd);
2388 dbdb = store_get(dbdb_size);
2393 HDEBUG(D_acl) debug_printf("ratelimit creating new Bloom filter\n");
2395 /* See the long comment below for an explanation of the magic number 2.
2396 The filter has a minimum size in case the rate limit is very small;
2397 this is determined by the definition of dbdata_ratelimit_unique. */
2399 extra = (int)limit * 2 - sizeof(dbdb->bloom);
2400 if (extra < 0) extra = 0;
2401 dbdb_size = sizeof(*dbdb) + extra;
2402 dbdb = store_get(dbdb_size);
2403 dbdb->bloom_epoch = tv.tv_sec;
2404 dbdb->bloom_size = sizeof(dbdb->bloom) + extra;
2405 memset(dbdb->bloom, 0, dbdb->bloom_size);
2407 /* Preserve any basic ratelimit data (which is our longer-term memory)
2408 by copying it from the discarded block. */
2418 /* If we are counting unique events, find out if this event is new or not.
2419 If the client repeats the event during the current period then it should be
2420 counted. We skip this code in readonly mode for efficiency, because any
2421 changes to the filter will be discarded and because count is already set to
2424 if (unique != NULL && !readonly)
2426 /* We identify unique events using a Bloom filter. (You can find my
2427 notes on Bloom filters at http://fanf.livejournal.com/81696.html)
2428 With the per_addr option, an "event" is a recipient address, though the
2429 user can use the unique option to define their own events. We only count
2430 an event if we have not seen it before.
2432 We size the filter according to the rate limit, which (in leaky mode)
2433 is the limit on the population of the filter. We allow 16 bits of space
2434 per entry (see the construction code above) and we set (up to) 8 of them
2435 when inserting an element (see the loop below). The probability of a false
2436 positive (an event we have not seen before but which we fail to count) is
2440 allzero = exp(-numhash * pop / size)
2441 = exp(-0.5 * pop / limit)
2442 fpr = pow(1 - allzero, numhash)
2444 For senders at the limit the fpr is 0.06% or 1 in 1700
2445 and for senders at half the limit it is 0.0006% or 1 in 170000
2447 In strict mode the Bloom filter can fill up beyond the normal limit, in
2448 which case the false positive rate will rise. This means that the
2449 measured rate for very fast senders can bogusly drop off after a while.
2451 At twice the limit, the fpr is 2.5% or 1 in 40
2452 At four times the limit, it is 31% or 1 in 3.2
2454 It takes ln(pop/limit) periods for an over-limit burst of pop events to
2455 decay below the limit, and if this is more than one then the Bloom filter
2456 will be discarded before the decay gets that far. The false positive rate
2457 at this threshold is 9.3% or 1 in 10.7. */
2460 unsigned n, hash, hinc;
2464 /* Instead of using eight independent hash values, we combine two values
2465 using the formula h1 + n * h2. This does not harm the Bloom filter's
2466 performance, and means the amount of hash we need is independent of the
2467 number of bits we set in the filter. */
2469 md5_start(&md5info);
2470 md5_end(&md5info, unique, Ustrlen(unique), md5sum);
2471 hash = md5sum[0] | md5sum[1] << 8 | md5sum[2] << 16 | md5sum[3] << 24;
2472 hinc = md5sum[4] | md5sum[5] << 8 | md5sum[6] << 16 | md5sum[7] << 24;
2474 /* Scan the bits corresponding to this event. A zero bit means we have
2475 not seen it before. Ensure all bits are set to record this event. */
2477 HDEBUG(D_acl) debug_printf("ratelimit checking uniqueness of %s\n", unique);
2480 for (n = 0; n < 8; n++, hash += hinc)
2482 int bit = 1 << (hash % 8);
2483 int byte = (hash / 8) % dbdb->bloom_size;
2484 if ((dbdb->bloom[byte] & bit) == 0)
2486 dbdb->bloom[byte] |= bit;
2491 /* If this event has occurred before, do not count it. */
2495 HDEBUG(D_acl) debug_printf("ratelimit event found in Bloom filter\n");
2499 HDEBUG(D_acl) debug_printf("ratelimit event added to Bloom filter\n");
2502 /* If there was no previous ratelimit data block for this key, initialize
2503 the new one, otherwise update the block from the database. The initial rate
2504 is what would be computed by the code below for an infinite interval. */
2508 HDEBUG(D_acl) debug_printf("ratelimit initializing new key's rate data\n");
2510 dbd->time_stamp = tv.tv_sec;
2511 dbd->time_usec = tv.tv_usec;
2516 /* The smoothed rate is computed using an exponentially weighted moving
2517 average adjusted for variable sampling intervals. The standard EWMA for
2518 a fixed sampling interval is: f'(t) = (1 - a) * f(t) + a * f'(t - 1)
2519 where f() is the measured value and f'() is the smoothed value.
2521 Old data decays out of the smoothed value exponentially, such that data n
2522 samples old is multiplied by a^n. The exponential decay time constant p
2523 is defined such that data p samples old is multiplied by 1/e, which means
2524 that a = exp(-1/p). We can maintain the same time constant for a variable
2525 sampling interval i by using a = exp(-i/p).
2527 The rate we are measuring is messages per period, suitable for directly
2528 comparing with the limit. The average rate between now and the previous
2529 message is period / interval, which we feed into the EWMA as the sample.
2531 It turns out that the number of messages required for the smoothed rate
2532 to reach the limit when they are sent in a burst is equal to the limit.
2533 This can be seen by analysing the value of the smoothed rate after N
2534 messages sent at even intervals. Let k = (1 - a) * p/i
2536 rate_1 = (1 - a) * p/i + a * rate_0
2538 rate_2 = k + a * rate_1
2539 = k + a * k + a^2 * rate_0
2540 rate_3 = k + a * k + a^2 * k + a^3 * rate_0
2541 rate_N = rate_0 * a^N + k * SUM(x=0..N-1)(a^x)
2542 = rate_0 * a^N + k * (1 - a^N) / (1 - a)
2543 = rate_0 * a^N + p/i * (1 - a^N)
2545 When N is large, a^N -> 0 so rate_N -> p/i as desired.
2547 rate_N = p/i + (rate_0 - p/i) * a^N
2548 a^N = (rate_N - p/i) / (rate_0 - p/i)
2549 N * -i/p = log((rate_N - p/i) / (rate_0 - p/i))
2550 N = p/i * log((rate_0 - p/i) / (rate_N - p/i))
2552 Numerical analysis of the above equation, setting the computed rate to
2553 increase from rate_0 = 0 to rate_N = limit, shows that for large sending
2554 rates, p/i, the number of messages N = limit. So limit serves as both the
2555 maximum rate measured in messages per period, and the maximum number of
2556 messages that can be sent in a fast burst. */
2558 double this_time = (double)tv.tv_sec
2559 + (double)tv.tv_usec / 1000000.0;
2560 double prev_time = (double)dbd->time_stamp
2561 + (double)dbd->time_usec / 1000000.0;
2563 /* We must avoid division by zero, and deal gracefully with the clock going
2564 backwards. If we blunder ahead when time is in reverse then the computed
2565 rate will be bogus. To be safe we clamp interval to a very small number. */
2567 double interval = this_time - prev_time <= 0.0 ? 1e-9
2568 : this_time - prev_time;
2570 double i_over_p = interval / period;
2571 double a = exp(-i_over_p);
2573 /* Combine the instantaneous rate (period / interval) with the previous rate
2574 using the smoothing factor a. In order to measure sized events, multiply the
2575 instantaneous rate by the count of bytes or recipients etc. */
2577 dbd->time_stamp = tv.tv_sec;
2578 dbd->time_usec = tv.tv_usec;
2579 dbd->rate = (1 - a) * count / i_over_p + a * dbd->rate;
2581 /* When events are very widely spaced the computed rate tends towards zero.
2582 Although this is accurate it turns out not to be useful for our purposes,
2583 especially when the first event after a long silence is the start of a spam
2584 run. A more useful model is that the rate for an isolated event should be the
2585 size of the event per the period size, ignoring the lack of events outside
2586 the current period and regardless of where the event falls in the period. So,
2587 if the interval was so long that the calculated rate is unhelpfully small, we
2588 re-intialize the rate. In the absence of higher-rate bursts, the condition
2589 below is true if the interval is greater than the period. */
2591 if (dbd->rate < count) dbd->rate = count;
2594 /* Clients sending at the limit are considered to be over the limit.
2595 This matters for edge cases such as a limit of zero, when the client
2596 should be completely blocked. */
2598 rc = (dbd->rate < limit)? FAIL : OK;
2600 /* Update the state if the rate is low or if we are being strict. If we
2601 are in leaky mode and the sender's rate is too high, we do not update
2602 the recorded rate in order to avoid an over-aggressive sender's retry
2603 rate preventing them from getting any email through. If readonly is set,
2604 neither leaky nor strict are set, so we do not do any updates. */
2606 if ((rc == FAIL && leaky) || strict)
2608 dbfn_write(dbm, key, dbdb, dbdb_size);
2609 HDEBUG(D_acl) debug_printf("ratelimit db updated\n");
2613 HDEBUG(D_acl) debug_printf("ratelimit db not updated: %s\n",
2614 readonly? "readonly mode" : "over the limit, but leaky");
2619 /* Store the result in the tree for future reference. */
2621 t = store_get(sizeof(tree_node) + Ustrlen(key));
2623 Ustrcpy(t->name, key);
2624 (void)tree_insertnode(anchor, t);
2626 /* We create the formatted version of the sender's rate very late in
2627 order to ensure that it is done using the correct storage pool. */
2629 store_pool = old_pool;
2630 sender_rate = string_sprintf("%.1f", dbd->rate);
2633 debug_printf("ratelimit computed rate %s\n", sender_rate);
2640 /*************************************************
2641 * Handle conditions/modifiers on an ACL item *
2642 *************************************************/
2644 /* Called from acl_check() below.
2648 cb ACL condition block - if NULL, result is OK
2649 where where called from
2650 addr the address being checked for RCPT, or NULL
2651 level the nesting level
2652 epp pointer to pass back TRUE if "endpass" encountered
2653 (applies only to "accept" and "discard")
2654 user_msgptr user message pointer
2655 log_msgptr log message pointer
2656 basic_errno pointer to where to put verify error
2658 Returns: OK - all conditions are met
2659 DISCARD - an "acl" condition returned DISCARD - only allowed
2660 for "accept" or "discard" verbs
2661 FAIL - at least one condition fails
2662 FAIL_DROP - an "acl" condition returned FAIL_DROP
2663 DEFER - can't tell at the moment (typically, lookup defer,
2664 but can be temporary callout problem)
2665 ERROR - ERROR from nested ACL or expansion failure or other
2670 acl_check_condition(int verb, acl_condition_block *cb, int where,
2671 address_item *addr, int level, BOOL *epp, uschar **user_msgptr,
2672 uschar **log_msgptr, int *basic_errno)
2674 uschar *user_message = NULL;
2675 uschar *log_message = NULL;
2676 uschar *debug_tag = NULL;
2677 uschar *debug_opts = NULL;
2680 #ifdef WITH_CONTENT_SCAN
2684 for (; cb != NULL; cb = cb->next)
2689 /* The message and log_message items set up messages to be used in
2690 case of rejection. They are expanded later. */
2692 if (cb->type == ACLC_MESSAGE)
2694 user_message = cb->arg;
2698 if (cb->type == ACLC_LOG_MESSAGE)
2700 log_message = cb->arg;
2704 /* The endpass "condition" just sets a flag to show it occurred. This is
2705 checked at compile time to be on an "accept" or "discard" item. */
2707 if (cb->type == ACLC_ENDPASS)
2713 /* For other conditions and modifiers, the argument is expanded now for some
2714 of them, but not for all, because expansion happens down in some lower level
2715 checking functions in some cases. */
2717 if (cond_expand_at_top[cb->type])
2719 arg = expand_string(cb->arg);
2722 if (expand_string_forcedfail) continue;
2723 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s",
2724 cb->arg, expand_string_message);
2725 return search_find_defer? DEFER : ERROR;
2730 /* Show condition, and expanded condition if it's different */
2735 debug_printf("check %s%s %n",
2736 (!cond_modifiers[cb->type] && cb->u.negated)? "!":"",
2737 conditions[cb->type], &lhswidth);
2739 if (cb->type == ACLC_SET)
2741 debug_printf("acl_%s ", cb->u.varname);
2742 lhswidth += 5 + Ustrlen(cb->u.varname);
2745 debug_printf("= %s\n", cb->arg);
2748 debug_printf("%.*s= %s\n", lhswidth,
2752 /* Check that this condition makes sense at this time */
2754 if ((cond_forbids[cb->type] & (1 << where)) != 0)
2756 *log_msgptr = string_sprintf("cannot %s %s condition in %s ACL",
2757 cond_modifiers[cb->type]? "use" : "test",
2758 conditions[cb->type], acl_wherenames[where]);
2762 /* Run the appropriate test for each condition, or take the appropriate
2763 action for the remaining modifiers. */
2767 case ACLC_ADD_HEADER:
2771 /* A nested ACL that returns "discard" makes sense only for an "accept" or
2775 rc = acl_check_internal(where, addr, arg, level+1, user_msgptr, log_msgptr);
2776 if (rc == DISCARD && verb != ACL_ACCEPT && verb != ACL_DISCARD)
2778 *log_msgptr = string_sprintf("nested ACL returned \"discard\" for "
2779 "\"%s\" command (only allowed with \"accept\" or \"discard\")",
2785 case ACLC_AUTHENTICATED:
2786 rc = (sender_host_authenticated == NULL)? FAIL :
2787 match_isinlist(sender_host_authenticated, &arg, 0, NULL, NULL, MCL_STRING,
2791 #ifdef EXPERIMENTAL_BRIGHTMAIL
2792 case ACLC_BMI_OPTIN:
2794 int old_pool = store_pool;
2795 store_pool = POOL_PERM;
2796 bmi_current_optin = string_copy(arg);
2797 store_pool = old_pool;
2802 case ACLC_CONDITION:
2803 /* The true/false parsing here should be kept in sync with that used in
2804 expand.c when dealing with ECOND_BOOL so that we don't have too many
2805 different definitions of what can be a boolean. */
2806 if (Ustrspn(arg, "0123456789") == Ustrlen(arg)) /* Digits, or empty */
2807 rc = (Uatoi(arg) == 0)? FAIL : OK;
2809 rc = (strcmpic(arg, US"no") == 0 ||
2810 strcmpic(arg, US"false") == 0)? FAIL :
2811 (strcmpic(arg, US"yes") == 0 ||
2812 strcmpic(arg, US"true") == 0)? OK : DEFER;
2814 *log_msgptr = string_sprintf("invalid \"condition\" value \"%s\"", arg);
2817 case ACLC_CONTINUE: /* Always succeeds */
2821 control_type = decode_control(arg, &p, where, log_msgptr);
2823 /* Check if this control makes sense at this time */
2825 if ((control_forbids[control_type] & (1 << where)) != 0)
2827 *log_msgptr = string_sprintf("cannot use \"control=%s\" in %s ACL",
2828 controls[control_type], acl_wherenames[where]);
2832 switch(control_type)
2834 case CONTROL_AUTH_UNADVERTISED:
2835 allow_auth_unadvertised = TRUE;
2838 #ifdef EXPERIMENTAL_BRIGHTMAIL
2839 case CONTROL_BMI_RUN:
2844 #ifndef DISABLE_DKIM
2845 case CONTROL_DKIM_VERIFY:
2846 dkim_disable_verify = TRUE;
2853 case CONTROL_CASEFUL_LOCAL_PART:
2854 deliver_localpart = addr->cc_local_part;
2857 case CONTROL_CASELOWER_LOCAL_PART:
2858 deliver_localpart = addr->lc_local_part;
2861 case CONTROL_ENFORCE_SYNC:
2862 smtp_enforce_sync = TRUE;
2865 case CONTROL_NO_ENFORCE_SYNC:
2866 smtp_enforce_sync = FALSE;
2869 #ifdef WITH_CONTENT_SCAN
2870 case CONTROL_NO_MBOX_UNSPOOL:
2871 no_mbox_unspool = TRUE;
2875 case CONTROL_NO_MULTILINE:
2876 no_multiline_responses = TRUE;
2879 case CONTROL_NO_PIPELINING:
2880 pipelining_enable = FALSE;
2883 case CONTROL_NO_DELAY_FLUSH:
2884 disable_delay_flush = TRUE;
2887 case CONTROL_NO_CALLOUT_FLUSH:
2888 disable_callout_flush = TRUE;
2891 case CONTROL_FAKEDEFER:
2892 case CONTROL_FAKEREJECT:
2893 fake_response = (control_type == CONTROL_FAKEDEFER) ? DEFER : FAIL;
2897 while (*pp != 0) pp++;
2898 fake_response_text = expand_string(string_copyn(p+1, pp-p-1));
2903 /* Explicitly reset to default string */
2904 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).";
2908 case CONTROL_FREEZE:
2909 deliver_freeze = TRUE;
2910 deliver_frozen_at = time(NULL);
2911 freeze_tell = freeze_tell_config; /* Reset to configured value */
2912 if (Ustrncmp(p, "/no_tell", 8) == 0)
2919 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2924 case CONTROL_QUEUE_ONLY:
2925 queue_only_policy = TRUE;
2928 case CONTROL_SUBMISSION:
2929 originator_name = US"";
2930 submission_mode = TRUE;
2933 if (Ustrncmp(p, "/sender_retain", 14) == 0)
2936 active_local_sender_retain = TRUE;
2937 active_local_from_check = FALSE;
2939 else if (Ustrncmp(p, "/domain=", 8) == 0)
2942 while (*pp != 0 && *pp != '/') pp++;
2943 submission_domain = string_copyn(p+8, pp-p-8);
2946 /* The name= option must be last, because it swallows the rest of
2948 else if (Ustrncmp(p, "/name=", 6) == 0)
2951 while (*pp != 0) pp++;
2952 submission_name = string_copy(parse_fix_phrase(p+6, pp-p-6,
2953 big_buffer, big_buffer_size));
2960 *log_msgptr = string_sprintf("syntax error in \"control=%s\"", arg);
2968 if (Ustrncmp(p, "/tag=", 5) == 0)
2971 while (*pp != '\0' && *pp != '/') pp++;
2972 debug_tag = string_copyn(p+5, pp-p-5);
2975 else if (Ustrncmp(p, "/opts=", 6) == 0)
2978 while (*pp != '\0' && *pp != '/') pp++;
2979 debug_opts = string_copyn(p+6, pp-p-6);
2983 debug_logging_activate(debug_tag, debug_opts);
2986 case CONTROL_SUPPRESS_LOCAL_FIXUPS:
2987 suppress_local_fixups = TRUE;
2992 #ifdef EXPERIMENTAL_DCC
2995 /* Seperate the regular expression and any optional parameters. */
2996 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
2997 /* Run the dcc backend. */
2998 rc = dcc_process(&ss);
2999 /* Modify return code based upon the existance of options. */
3000 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3002 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3004 /* FAIL so that the message is passed to the next ACL */
3012 #ifdef WITH_CONTENT_SCAN
3014 rc = mime_decode(&arg);
3020 int delay = readconf_readtime(arg, 0, FALSE);
3023 *log_msgptr = string_sprintf("syntax error in argument for \"delay\" "
3024 "modifier: \"%s\" is not a time value", arg);
3029 HDEBUG(D_acl) debug_printf("delay modifier requests %d-second delay\n",
3034 debug_printf("delay skipped in -bh checking mode\n");
3037 /* It appears to be impossible to detect that a TCP/IP connection has
3038 gone away without reading from it. This means that we cannot shorten
3039 the delay below if the client goes away, because we cannot discover
3040 that the client has closed its end of the connection. (The connection
3041 is actually in a half-closed state, waiting for the server to close its
3042 end.) It would be nice to be able to detect this state, so that the
3043 Exim process is not held up unnecessarily. However, it seems that we
3044 can't. The poll() function does not do the right thing, and in any case
3045 it is not always available.
3047 NOTE 1: If ever this state of affairs changes, remember that we may be
3048 dealing with stdin/stdout here, in addition to TCP/IP connections.
3049 Also, delays may be specified for non-SMTP input, where smtp_out and
3050 smtp_in will be NULL. Whatever is done must work in all cases.
3052 NOTE 2: The added feature of flushing the output before a delay must
3053 apply only to SMTP input. Hence the test for smtp_out being non-NULL.
3058 if (smtp_out != NULL && !disable_delay_flush) mac_smtp_fflush();
3059 while (delay > 0) delay = sleep(delay);
3065 #ifdef WITH_OLD_DEMIME
3071 #ifndef DISABLE_DKIM
3072 case ACLC_DKIM_SIGNER:
3073 if (dkim_cur_signer != NULL)
3074 rc = match_isinlist(dkim_cur_signer,
3075 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3080 case ACLC_DKIM_STATUS:
3081 rc = match_isinlist(dkim_exim_expand_query(DKIM_VERIFY_STATUS),
3082 &arg,0,NULL,NULL,MCL_STRING,TRUE,NULL);
3087 rc = verify_check_dnsbl(&arg);
3091 rc = match_isinlist(addr->domain, &arg, 0, &domainlist_anchor,
3092 addr->domain_cache, MCL_DOMAIN, TRUE, &deliver_domain_data);
3095 /* The value in tls_cipher is the full cipher name, for example,
3096 TLSv1:DES-CBC3-SHA:168, whereas the values to test for are just the
3097 cipher names such as DES-CBC3-SHA. But program defensively. We don't know
3098 what may in practice come out of the SSL library - which at the time of
3099 writing is poorly documented. */
3101 case ACLC_ENCRYPTED:
3102 if (tls_cipher == NULL) rc = FAIL; else
3104 uschar *endcipher = NULL;
3105 uschar *cipher = Ustrchr(tls_cipher, ':');
3106 if (cipher == NULL) cipher = tls_cipher; else
3108 endcipher = Ustrchr(++cipher, ':');
3109 if (endcipher != NULL) *endcipher = 0;
3111 rc = match_isinlist(cipher, &arg, 0, NULL, NULL, MCL_STRING, TRUE, NULL);
3112 if (endcipher != NULL) *endcipher = ':';
3116 /* Use verify_check_this_host() instead of verify_check_host() so that
3117 we can pass over &host_data to catch any looked up data. Once it has been
3118 set, it retains its value so that it's still there if another ACL verb
3119 comes through here and uses the cache. However, we must put it into
3120 permanent store in case it is also expected to be used in a subsequent
3121 message in the same SMTP connection. */
3124 rc = verify_check_this_host(&arg, sender_host_cache, NULL,
3125 (sender_host_address == NULL)? US"" : sender_host_address, &host_data);
3126 if (host_data != NULL) host_data = string_copy_malloc(host_data);
3129 case ACLC_LOCAL_PARTS:
3130 rc = match_isinlist(addr->cc_local_part, &arg, 0,
3131 &localpartlist_anchor, addr->localpart_cache, MCL_LOCALPART, TRUE,
3132 &deliver_localpart_data);
3135 case ACLC_LOG_REJECT_TARGET:
3141 while ((ss = string_nextinlist(&s, &sep, big_buffer, big_buffer_size))
3144 if (Ustrcmp(ss, "main") == 0) logbits |= LOG_MAIN;
3145 else if (Ustrcmp(ss, "panic") == 0) logbits |= LOG_PANIC;
3146 else if (Ustrcmp(ss, "reject") == 0) logbits |= LOG_REJECT;
3149 logbits |= LOG_MAIN|LOG_REJECT;
3150 log_write(0, LOG_MAIN|LOG_PANIC, "unknown log name \"%s\" in "
3151 "\"log_reject_target\" in %s ACL", ss, acl_wherenames[where]);
3154 log_reject_target = logbits;
3167 if (Ustrncmp(s, "main", 4) == 0)
3168 { logbits |= LOG_MAIN; s += 4; }
3169 else if (Ustrncmp(s, "panic", 5) == 0)
3170 { logbits |= LOG_PANIC; s += 5; }
3171 else if (Ustrncmp(s, "reject", 6) == 0)
3172 { logbits |= LOG_REJECT; s += 6; }
3175 logbits = LOG_MAIN|LOG_PANIC;
3176 s = string_sprintf(":unknown log name in \"%s\" in "
3177 "\"logwrite\" in %s ACL", arg, acl_wherenames[where]);
3183 while (isspace(*s)) s++;
3186 if (logbits == 0) logbits = LOG_MAIN;
3187 log_write(0, logbits, "%s", string_printing(s));
3191 #ifdef WITH_CONTENT_SCAN
3194 /* Separate the regular expression and any optional parameters. */
3195 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3196 /* Run the malware backend. */
3198 /* Modify return code based upon the existance of options. */
3199 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3201 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3203 /* FAIL so that the message is passed to the next ACL */
3210 case ACLC_MIME_REGEX:
3211 rc = mime_regex(&arg);
3215 case ACLC_RATELIMIT:
3216 rc = acl_ratelimit(arg, where, log_msgptr);
3219 case ACLC_RECIPIENTS:
3220 rc = match_address_list(addr->address, TRUE, TRUE, &arg, NULL, -1, 0,
3224 #ifdef WITH_CONTENT_SCAN
3230 case ACLC_SENDER_DOMAINS:
3233 sdomain = Ustrrchr(sender_address, '@');
3234 sdomain = (sdomain == NULL)? US"" : sdomain + 1;
3235 rc = match_isinlist(sdomain, &arg, 0, &domainlist_anchor,
3236 sender_domain_cache, MCL_DOMAIN, TRUE, NULL);
3241 rc = match_address_list(sender_address, TRUE, TRUE, &arg,
3242 sender_address_cache, -1, 0, &sender_data);
3245 /* Connection variables must persist forever */
3249 int old_pool = store_pool;
3250 if (cb->u.varname[0] == 'c') store_pool = POOL_PERM;
3251 acl_var_create(cb->u.varname)->data.ptr = string_copy(arg);
3252 store_pool = old_pool;
3256 #ifdef WITH_CONTENT_SCAN
3259 /* Seperate the regular expression and any optional parameters. */
3260 uschar *ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size);
3261 /* Run the spam backend. */
3263 /* Modify return code based upon the existance of options. */
3264 while ((ss = string_nextinlist(&arg, &sep, big_buffer, big_buffer_size))
3266 if (strcmpic(ss, US"defer_ok") == 0 && rc == DEFER)
3268 /* FAIL so that the message is passed to the next ACL */
3276 #ifdef EXPERIMENTAL_SPF
3278 rc = spf_process(&arg, sender_address, SPF_PROCESS_NORMAL);
3280 case ACLC_SPF_GUESS:
3281 rc = spf_process(&arg, sender_address, SPF_PROCESS_GUESS);
3285 /* If the verb is WARN, discard any user message from verification, because
3286 such messages are SMTP responses, not header additions. The latter come
3287 only from explicit "message" modifiers. However, put the user message into
3288 $acl_verify_message so it can be used in subsequent conditions or modifiers
3289 (until something changes it). */
3292 rc = acl_verify(where, addr, arg, user_msgptr, log_msgptr, basic_errno);
3293 acl_verify_message = *user_msgptr;
3294 if (verb == ACL_WARN) *user_msgptr = NULL;
3298 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown "
3299 "condition %d", cb->type);
3303 /* If a condition was negated, invert OK/FAIL. */
3305 if (!cond_modifiers[cb->type] && cb->u.negated)
3307 if (rc == OK) rc = FAIL;
3308 else if (rc == FAIL || rc == FAIL_DROP) rc = OK;
3311 if (rc != OK) break; /* Conditions loop */
3315 /* If the result is the one for which "message" and/or "log_message" are used,
3316 handle the values of these modifiers. If there isn't a log message set, we make
3317 it the same as the user message.
3319 "message" is a user message that will be included in an SMTP response. Unless
3320 it is empty, it overrides any previously set user message.
3322 "log_message" is a non-user message, and it adds to any existing non-user
3323 message that is already set.
3325 Most verbs have but a single return for which the messages are relevant, but
3326 for "discard", it's useful to have the log message both when it succeeds and
3327 when it fails. For "accept", the message is used in the OK case if there is no
3328 "endpass", but (for backwards compatibility) in the FAIL case if "endpass" is
3331 if (*epp && rc == OK) user_message = NULL;
3333 if (((1<<rc) & msgcond[verb]) != 0)
3336 uschar *old_user_msgptr = *user_msgptr;
3337 uschar *old_log_msgptr = (*log_msgptr != NULL)? *log_msgptr : old_user_msgptr;
3339 /* If the verb is "warn", messages generated by conditions (verification or
3340 nested ACLs) are always discarded. This also happens for acceptance verbs
3341 when they actually do accept. Only messages specified at this level are used.
3342 However, the value of an existing message is available in $acl_verify_message
3343 during expansions. */
3345 if (verb == ACL_WARN ||
3346 (rc == OK && (verb == ACL_ACCEPT || verb == ACL_DISCARD)))
3347 *log_msgptr = *user_msgptr = NULL;
3349 if (user_message != NULL)
3351 acl_verify_message = old_user_msgptr;
3352 expmessage = expand_string(user_message);
3353 if (expmessage == NULL)
3355 if (!expand_string_forcedfail)
3356 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3357 user_message, expand_string_message);
3359 else if (expmessage[0] != 0) *user_msgptr = expmessage;
3362 if (log_message != NULL)
3364 acl_verify_message = old_log_msgptr;
3365 expmessage = expand_string(log_message);
3366 if (expmessage == NULL)
3368 if (!expand_string_forcedfail)
3369 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand ACL message \"%s\": %s",
3370 log_message, expand_string_message);
3372 else if (expmessage[0] != 0)
3374 *log_msgptr = (*log_msgptr == NULL)? expmessage :
3375 string_sprintf("%s: %s", expmessage, *log_msgptr);
3379 /* If no log message, default it to the user message */
3381 if (*log_msgptr == NULL) *log_msgptr = *user_msgptr;
3384 acl_verify_message = NULL;
3392 /*************************************************
3393 * Get line from a literal ACL *
3394 *************************************************/
3396 /* This function is passed to acl_read() in order to extract individual lines
3397 of a literal ACL, which we access via static pointers. We can destroy the
3398 contents because this is called only once (the compiled ACL is remembered).
3400 This code is intended to treat the data in the same way as lines in the main
3401 Exim configuration file. That is:
3403 . Leading spaces are ignored.
3405 . A \ at the end of a line is a continuation - trailing spaces after the \
3406 are permitted (this is because I don't believe in making invisible things
3407 significant). Leading spaces on the continued part of a line are ignored.
3409 . Physical lines starting (significantly) with # are totally ignored, and
3410 may appear within a sequence of backslash-continued lines.
3412 . Blank lines are ignored, but will end a sequence of continuations.
3415 Returns: a pointer to the next line
3419 static uschar *acl_text; /* Current pointer in the text */
3420 static uschar *acl_text_end; /* Points one past the terminating '0' */
3428 /* This loop handles leading blank lines and comments. */
3432 while (isspace(*acl_text)) acl_text++; /* Leading spaces/empty lines */
3433 if (*acl_text == 0) return NULL; /* No more data */
3434 yield = acl_text; /* Potential data line */
3436 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3438 /* If we hit the end before a newline, we have the whole logical line. If
3439 it's a comment, there's no more data to be given. Otherwise, yield it. */
3441 if (*acl_text == 0) return (*yield == '#')? NULL : yield;
3443 /* After reaching a newline, end this loop if the physical line does not
3444 start with '#'. If it does, it's a comment, and the loop continues. */
3446 if (*yield != '#') break;
3449 /* This loop handles continuations. We know we have some real data, ending in
3450 newline. See if there is a continuation marker at the end (ignoring trailing
3451 white space). We know that *yield is not white space, so no need to test for
3452 cont > yield in the backwards scanning loop. */
3457 for (cont = acl_text - 1; isspace(*cont); cont--);
3459 /* If no continuation follows, we are done. Mark the end of the line and
3468 /* We have encountered a continuation. Skip over whitespace at the start of
3469 the next line, and indeed the whole of the next line or lines if they are
3474 while (*(++acl_text) == ' ' || *acl_text == '\t');
3475 if (*acl_text != '#') break;
3476 while (*(++acl_text) != 0 && *acl_text != '\n');
3479 /* We have the start of a continuation line. Move all the rest of the data
3480 to join onto the previous line, and then find its end. If the end is not a
3481 newline, we are done. Otherwise loop to look for another continuation. */
3483 memmove(cont, acl_text, acl_text_end - acl_text);
3484 acl_text_end -= acl_text - cont;
3486 while (*acl_text != 0 && *acl_text != '\n') acl_text++;
3487 if (*acl_text == 0) return yield;
3490 /* Control does not reach here */
3497 /*************************************************
3498 * Check access using an ACL *
3499 *************************************************/
3501 /* This function is called from address_check. It may recurse via
3502 acl_check_condition() - hence the use of a level to stop looping. The ACL is
3503 passed as a string which is expanded. A forced failure implies no access check
3504 is required. If the result is a single word, it is taken as the name of an ACL
3505 which is sought in the global ACL tree. Otherwise, it is taken as literal ACL
3506 text, complete with newlines, and parsed as such. In both cases, the ACL check
3507 is then run. This function uses an auxiliary function for acl_read() to call
3508 for reading individual lines of a literal ACL. This is acl_getline(), which
3509 appears immediately above.
3512 where where called from
3513 addr address item when called from RCPT; otherwise NULL
3514 s the input string; NULL is the same as an empty ACL => DENY
3515 level the nesting level
3516 user_msgptr where to put a user error (for SMTP response)
3517 log_msgptr where to put a logging message (not for SMTP response)
3519 Returns: OK access is granted
3520 DISCARD access is apparently granted...
3521 FAIL access is denied
3522 FAIL_DROP access is denied; drop the connection
3523 DEFER can't tell at the moment
3528 acl_check_internal(int where, address_item *addr, uschar *s, int level,
3529 uschar **user_msgptr, uschar **log_msgptr)
3532 acl_block *acl = NULL;
3533 uschar *acl_name = US"inline ACL";
3536 /* Catch configuration loops */
3540 *log_msgptr = US"ACL nested too deep: possible loop";
3546 HDEBUG(D_acl) debug_printf("ACL is NULL: implicit DENY\n");
3550 /* At top level, we expand the incoming string. At lower levels, it has already
3551 been expanded as part of condition processing. */
3555 ss = expand_string(s);
3558 if (expand_string_forcedfail) return OK;
3559 *log_msgptr = string_sprintf("failed to expand ACL string \"%s\": %s", s,
3560 expand_string_message);
3566 while (isspace(*ss))ss++;
3568 /* If we can't find a named ACL, the default is to parse it as an inline one.
3569 (Unless it begins with a slash; non-existent files give rise to an error.) */
3573 /* Handle the case of a string that does not contain any spaces. Look for a
3574 named ACL among those read from the configuration, or a previously read file.
3575 It is possible that the pointer to the ACL is NULL if the configuration
3576 contains a name with no data. If not found, and the text begins with '/',
3577 read an ACL from a file, and save it so it can be re-used. */
3579 if (Ustrchr(ss, ' ') == NULL)
3581 tree_node *t = tree_search(acl_anchor, ss);
3584 acl = (acl_block *)(t->data.ptr);
3587 HDEBUG(D_acl) debug_printf("ACL \"%s\" is empty: implicit DENY\n", ss);
3590 acl_name = string_sprintf("ACL \"%s\"", ss);
3591 HDEBUG(D_acl) debug_printf("using ACL \"%s\"\n", ss);
3594 else if (*ss == '/')
3596 struct stat statbuf;
3597 fd = Uopen(ss, O_RDONLY, 0);
3600 *log_msgptr = string_sprintf("failed to open ACL file \"%s\": %s", ss,
3605 if (fstat(fd, &statbuf) != 0)
3607 *log_msgptr = string_sprintf("failed to fstat ACL file \"%s\": %s", ss,
3612 acl_text = store_get(statbuf.st_size + 1);
3613 acl_text_end = acl_text + statbuf.st_size + 1;
3615 if (read(fd, acl_text, statbuf.st_size) != statbuf.st_size)
3617 *log_msgptr = string_sprintf("failed to read ACL file \"%s\": %s",
3618 ss, strerror(errno));
3621 acl_text[statbuf.st_size] = 0;
3624 acl_name = string_sprintf("ACL \"%s\"", ss);
3625 HDEBUG(D_acl) debug_printf("read ACL from file %s\n", ss);
3629 /* Parse an ACL that is still in text form. If it came from a file, remember it
3630 in the ACL tree, having read it into the POOL_PERM store pool so that it
3631 persists between multiple messages. */
3635 int old_pool = store_pool;
3636 if (fd >= 0) store_pool = POOL_PERM;
3637 acl = acl_read(acl_getline, log_msgptr);
3638 store_pool = old_pool;
3639 if (acl == NULL && *log_msgptr != NULL) return ERROR;
3642 tree_node *t = store_get_perm(sizeof(tree_node) + Ustrlen(ss));
3643 Ustrcpy(t->name, ss);
3645 (void)tree_insertnode(&acl_anchor, t);
3649 /* Now we have an ACL to use. It's possible it may be NULL. */
3654 int basic_errno = 0;
3655 BOOL endpass_seen = FALSE;
3657 *log_msgptr = *user_msgptr = NULL;
3658 acl_temp_details = FALSE;
3660 if ((where == ACL_WHERE_QUIT || where == ACL_WHERE_NOTQUIT) &&
3661 acl->verb != ACL_ACCEPT &&
3662 acl->verb != ACL_WARN)
3664 *log_msgptr = string_sprintf("\"%s\" is not allowed in a QUIT or not-QUIT ACL",
3669 HDEBUG(D_acl) debug_printf("processing \"%s\"\n", verbs[acl->verb]);
3671 /* Clear out any search error message from a previous check before testing
3674 search_error_message = NULL;
3675 cond = acl_check_condition(acl->verb, acl->condition, where, addr, level,
3676 &endpass_seen, user_msgptr, log_msgptr, &basic_errno);
3678 /* Handle special returns: DEFER causes a return except on a WARN verb;
3679 ERROR always causes a return. */
3684 HDEBUG(D_acl) debug_printf("%s: condition test deferred in %s\n", verbs[acl->verb], acl_name);
3685 if (basic_errno != ERRNO_CALLOUTDEFER)
3687 if (search_error_message != NULL && *search_error_message != 0)
3688 *log_msgptr = search_error_message;
3689 if (smtp_return_error_details) acl_temp_details = TRUE;
3693 acl_temp_details = TRUE;
3695 if (acl->verb != ACL_WARN) return DEFER;
3698 default: /* Paranoia */
3700 HDEBUG(D_acl) debug_printf("%s: condition test error in %s\n", verbs[acl->verb], acl_name);
3704 HDEBUG(D_acl) debug_printf("%s: condition test succeeded in %s\n",
3705 verbs[acl->verb], acl_name);
3709 HDEBUG(D_acl) debug_printf("%s: condition test failed in %s\n", verbs[acl->verb], acl_name);
3712 /* DISCARD and DROP can happen only from a nested ACL condition, and
3713 DISCARD can happen only for an "accept" or "discard" verb. */
3716 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"discard\" in %s\n",
3717 verbs[acl->verb], acl_name);
3721 HDEBUG(D_acl) debug_printf("%s: condition test yielded \"drop\" in %s\n",
3722 verbs[acl->verb], acl_name);
3726 /* At this point, cond for most verbs is either OK or FAIL or (as a result of
3727 a nested ACL condition) FAIL_DROP. However, for WARN, cond may be DEFER, and
3728 for ACCEPT and DISCARD, it may be DISCARD after a nested ACL call. */
3733 if (cond == OK || cond == DISCARD) return cond;
3736 HDEBUG(D_acl) debug_printf("accept: endpass encountered - denying access\n");
3744 acl_temp_details = TRUE;
3750 if (cond == OK) return FAIL;
3754 if (cond == OK || cond == DISCARD) return DISCARD;
3757 HDEBUG(D_acl) debug_printf("discard: endpass encountered - denying access\n");
3763 if (cond == OK) return FAIL_DROP;
3767 if (cond != OK) return cond;
3772 acl_warn(where, *user_msgptr, *log_msgptr);
3773 else if (cond == DEFER && (log_extra_selector & LX_acl_warn_skipped) != 0)
3774 log_write(0, LOG_MAIN, "%s Warning: ACL \"warn\" statement skipped: "
3775 "condition test deferred%s%s", host_and_ident(TRUE),
3776 (*log_msgptr == NULL)? US"" : US": ",
3777 (*log_msgptr == NULL)? US"" : *log_msgptr);
3778 *log_msgptr = *user_msgptr = NULL; /* In case implicit DENY follows */
3782 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal ACL error: unknown verb %d",
3787 /* Pass to the next ACL item */
3792 /* We have reached the end of the ACL. This is an implicit DENY. */
3794 HDEBUG(D_acl) debug_printf("end of %s: implicit DENY\n", acl_name);
3799 /*************************************************
3800 * Check access using an ACL *
3801 *************************************************/
3803 /* This is the external interface for ACL checks. It sets up an address and the
3804 expansions for $domain and $local_part when called after RCPT, then calls
3805 acl_check_internal() to do the actual work.
3808 where ACL_WHERE_xxxx indicating where called from
3809 recipient RCPT address for RCPT check, else NULL
3810 s the input string; NULL is the same as an empty ACL => DENY
3811 user_msgptr where to put a user error (for SMTP response)
3812 log_msgptr where to put a logging message (not for SMTP response)
3814 Returns: OK access is granted by an ACCEPT verb
3815 DISCARD access is granted by a DISCARD verb
3816 FAIL access is denied
3817 FAIL_DROP access is denied; drop the connection
3818 DEFER can't tell at the moment
3823 acl_check(int where, uschar *recipient, uschar *s, uschar **user_msgptr,
3824 uschar **log_msgptr)
3828 address_item *addr = NULL;
3830 *user_msgptr = *log_msgptr = NULL;
3831 sender_verified_failed = NULL;
3832 ratelimiters_cmd = NULL;
3833 log_reject_target = LOG_MAIN|LOG_REJECT;
3835 if (where == ACL_WHERE_RCPT)
3837 adb = address_defaults;
3839 addr->address = recipient;
3840 if (deliver_split_address(addr) == DEFER)
3842 *log_msgptr = US"defer in percent_hack_domains check";
3845 deliver_domain = addr->domain;
3846 deliver_localpart = addr->local_part;
3849 rc = acl_check_internal(where, addr, s, 0, user_msgptr, log_msgptr);
3851 deliver_domain = deliver_localpart = deliver_address_data =
3852 sender_address_data = NULL;
3854 /* A DISCARD response is permitted only for message ACLs, excluding the PREDATA
3855 ACL, which is really in the middle of an SMTP command. */
3859 if (where > ACL_WHERE_NOTSMTP || where == ACL_WHERE_PREDATA)
3861 log_write(0, LOG_MAIN|LOG_PANIC, "\"discard\" verb not allowed in %s "
3862 "ACL", acl_wherenames[where]);
3868 /* A DROP response is not permitted from MAILAUTH */
3870 if (rc == FAIL_DROP && where == ACL_WHERE_MAILAUTH)
3872 log_write(0, LOG_MAIN|LOG_PANIC, "\"drop\" verb not allowed in %s "
3873 "ACL", acl_wherenames[where]);
3877 /* Before giving a response, take a look at the length of any user message, and
3878 split it up into multiple lines if possible. */
3880 *user_msgptr = string_split_message(*user_msgptr);
3881 if (fake_response != OK)
3882 fake_response_text = string_split_message(fake_response_text);
3889 /*************************************************
3890 * Create ACL variable *
3891 *************************************************/
3893 /* Create an ACL variable or reuse an existing one. ACL variables are in a
3894 binary tree (see tree.c) with acl_var_c and acl_var_m as root nodes.
3897 name pointer to the variable's name, starting with c or m
3899 Returns the pointer to variable's tree node
3903 acl_var_create(uschar *name)
3905 tree_node *node, **root;
3906 root = (name[0] == 'c')? &acl_var_c : &acl_var_m;
3907 node = tree_search(*root, name);
3910 node = store_get(sizeof(tree_node) + Ustrlen(name));
3911 Ustrcpy(node->name, name);
3912 (void)tree_insertnode(root, node);
3914 node->data.ptr = NULL;
3920 /*************************************************
3921 * Write an ACL variable in spool format *
3922 *************************************************/
3924 /* This function is used as a callback for tree_walk when writing variables to
3925 the spool file. To retain spool file compatibility, what is written is -aclc or
3926 -aclm followed by the rest of the name and the data length, space separated,
3927 then the value itself, starting on a new line, and terminated by an additional
3928 newline. When we had only numbered ACL variables, the first line might look
3929 like this: "-aclc 5 20". Now it might be "-aclc foo 20" for the variable called
3933 name of the variable
3934 value of the variable
3935 ctx FILE pointer (as a void pointer)
3941 acl_var_write(uschar *name, uschar *value, void *ctx)
3943 FILE *f = (FILE *)ctx;
3944 fprintf(f, "-acl%c %s %d\n%s\n", name[0], name+1, Ustrlen(value), value);