1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 address_item cutthrough_addr;
18 static smtp_outblock ctblock;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if ((options & vopt_callout_recipsender) != 0)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if ((options & vopt_callout_recippmaster) != 0)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
376 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
377 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
378 addr->transport->name, addr->transport->driver_name);
381 smtp_transport_options_block *ob =
382 (smtp_transport_options_block *)addr->transport->options_block;
384 /* The information wasn't available in the cache, so we have to do a real
385 callout and save the result in the cache for next time, unless no_cache is set,
386 or unless we have a previously cached negative random result. If we are to test
387 with a random local part, ensure that such a local part is available. If not,
388 log the fact, but carry on without randomming. */
390 if (callout_random && callout_random_local_part != NULL)
392 random_local_part = expand_string(callout_random_local_part);
393 if (random_local_part == NULL)
394 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
395 "callout_random_local_part: %s", expand_string_message);
398 /* Default the connect and overall callout timeouts if not set, and record the
399 time we are starting so that we can enforce it. */
401 if (callout_overall < 0) callout_overall = 4 * callout;
402 if (callout_connect < 0) callout_connect = callout;
403 callout_start_time = time(NULL);
405 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
406 output because a callout might take some time. When PIPELINING is active and
407 there are many recipients, the total time for doing lots of callouts can add up
408 and cause the client to time out. So in this case we forgo the PIPELINING
411 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
413 /* Now make connections to the hosts and do real callouts. The list of hosts
414 is passed in as an argument. */
416 for (host = host_list; host != NULL && !done; host = host->next)
418 smtp_inblock inblock;
419 smtp_outblock outblock;
422 BOOL send_quit = TRUE;
423 uschar *active_hostname = smtp_active_hostname;
427 BOOL suppress_tls = FALSE;
428 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
429 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
431 dns_answer tlsa_dnsa;
433 uschar inbuffer[4096];
434 uschar outbuffer[1024];
435 uschar responsebuffer[4096];
437 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
438 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
440 /* Skip this host if we don't have an IP address for it. */
442 if (host->address == NULL)
444 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
449 /* Check the overall callout timeout */
451 if (time(NULL) - callout_start_time >= callout_overall)
453 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
457 /* Set IPv4 or IPv6 */
459 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
461 /* Expand and interpret the interface and port strings. The latter will not
462 be used if there is a host-specific port (e.g. from a manualroute router).
463 This has to be delayed till now, because they may expand differently for
464 different hosts. If there's a failure, log it, but carry on with the
467 deliver_host = host->name;
468 deliver_host_address = host->address;
469 deliver_host_port = host->port;
470 deliver_domain = addr->domain;
471 transport_name = addr->transport->name;
473 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
475 !smtp_get_port(tf->port, addr, &port, US"callout"))
476 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
479 /* Set HELO string according to the protocol */
480 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
481 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
484 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
486 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
491 tls_out.dane_verified = FALSE;
492 tls_out.tlsa_usage = 0;
494 dane_required = verify_check_this_host(&ob->hosts_require_dane, NULL,
495 host->name, host->address, NULL) == OK;
497 if (host->dnssec == DS_YES)
500 || verify_check_this_host(&ob->hosts_try_dane, NULL,
501 host->name, host->address, NULL) == OK
503 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK)
506 else if (dane_required)
508 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
513 ob->tls_tempfail_tryclear = FALSE;
517 /* Set up the buffer for reading SMTP response packets. */
519 inblock.buffer = inbuffer;
520 inblock.buffersize = sizeof(inbuffer);
521 inblock.ptr = inbuffer;
522 inblock.ptrend = inbuffer;
524 /* Set up the buffer for holding SMTP commands while pipelining */
526 outblock.buffer = outbuffer;
527 outblock.buffersize = sizeof(outbuffer);
528 outblock.ptr = outbuffer;
529 outblock.cmd_count = 0;
530 outblock.authenticating = FALSE;
532 /* Reset the parameters of a TLS session */
533 tls_out.cipher = tls_out.peerdn = NULL;
535 /* Connect to the host; on failure, just loop for the next one, but we
536 set the error for the last one. Use the callout_connect timeout. */
538 tls_retry_connection:
540 inblock.sock = outblock.sock =
541 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL
542 #ifdef EXPERIMENTAL_EVENT
543 /*XXX event action? NULL for now. */
547 /* reconsider DSCP here */
548 if (inblock.sock < 0)
550 addr->message = string_sprintf("could not connect to %s [%s]: %s",
551 host->name, host->address, strerror(errno));
552 transport_name = NULL;
553 deliver_host = deliver_host_address = NULL;
554 deliver_domain = save_deliver_domain;
558 /* Expand the helo_data string to find the host name to use. */
560 if (tf->helo_data != NULL)
562 uschar *s = expand_string(tf->helo_data);
564 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
565 "helo_data value for callout: %s", addr->address,
566 expand_string_message);
567 else active_hostname = s;
570 /* Wait for initial response, and send HELO. The smtp_write_command()
571 function leaves its command in big_buffer. This is used in error responses.
572 Initialize it in case the connection is rejected. */
574 Ustrcpy(big_buffer, "initial connection");
576 /* Unless ssl-on-connect, wait for the initial greeting */
580 if (!smtps || (smtps && tls_out.active >= 0))
583 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
584 goto RESPONSE_FAILED;
586 #ifdef EXPERIMENTAL_EVENT
587 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
588 : host->dnssec==DS_NO ? US"no" : NULL;
589 if (event_raise(addr->transport->event_action,
590 US"smtp:connect", responsebuffer))
592 lookup_dnssec_authenticated = NULL;
593 /* Logging? Debug? */
594 goto RESPONSE_FAILED;
596 lookup_dnssec_authenticated = NULL;
600 /* Not worth checking greeting line for ESMTP support */
601 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
602 host->name, host->address, NULL) != OK))
604 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
609 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
612 ob->tls_tempfail_tryclear = FALSE;
614 else /* all other cases */
619 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
620 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
622 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
624 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
627 goto RESPONSE_FAILED;
633 goto esmtp_retry; /* fallback to HELO */
636 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
638 if (esmtp && !suppress_tls && tls_out.active < 0)
640 if (regex_STARTTLS == NULL) regex_STARTTLS =
641 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
643 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
644 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
651 /* If TLS is available on this connection attempt to
652 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
653 send another EHLO - the server may give a different answer in secure mode. We
654 use a separate buffer for reading the response to STARTTLS so that if it is
655 negative, the original EHLO data is available for subsequent analysis, should
656 the client not be required to use TLS. If the response is bad, copy the buffer
657 for error analysis. */
661 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
662 host->address, NULL) != OK &&
663 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
664 host->address, NULL) != OK
667 uschar buffer2[4096];
669 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
672 /* If there is an I/O error, transmission of this message is deferred. If
673 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
674 false, we also defer. However, if there is a temporary rejection of STARTTLS
675 and tls_tempfail_tryclear is true, or if there is an outright rejection of
676 STARTTLS, we carry on. This means we will try to send the message in clear,
677 unless the host is in hosts_require_tls (tested below). */
679 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
680 ob->command_timeout))
682 if (errno != 0 || buffer2[0] == 0 ||
683 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
685 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
687 goto RESPONSE_FAILED;
691 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
694 int oldtimeout = ob->command_timeout;
697 ob->command_timeout = callout;
698 rc = tls_client_start(inblock.sock, host, addr, addr->transport
699 #ifdef EXPERIMENTAL_DANE
700 , dane ? &tlsa_dnsa : NULL
703 ob->command_timeout = oldtimeout;
705 /* TLS negotiation failed; give an error. Try in clear on a new connection,
706 if the options permit it for this host. */
710 && ob->tls_tempfail_tryclear
712 && verify_check_this_host(&(ob->hosts_require_tls), NULL,
713 host->name, host->address, NULL) != OK
716 (void)close(inblock.sock);
717 #ifdef EXPERIMENTAL_EVENT
718 (void) event_raise(addr->transport->event_action,
719 US"tcp:close", NULL);
721 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
722 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
724 goto tls_retry_connection;
726 /*save_errno = ERRNO_TLSFAILURE;*/
727 /*message = US"failure while setting up TLS session";*/
733 /* TLS session is set up. Copy info for logging. */
734 addr->cipher = tls_out.cipher;
735 addr->peerdn = tls_out.peerdn;
737 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
739 goto smtps_redo_greeting;
741 /* For STARTTLS we need to redo EHLO */
746 /* If the host is required to use a secure channel, ensure that we have one. */
747 if (tls_out.active < 0)
749 #ifdef EXPERIMENTAL_DANE
752 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
753 host->address, NULL) == OK
756 /*save_errno = ERRNO_TLSREQUIRED;*/
757 log_write(0, LOG_MAIN,
758 "H=%s [%s]: a TLS session is required for this host, but %s",
759 host->name, host->address,
760 tls_offered ? "an attempt to start TLS failed"
761 : "the server did not offer TLS support");
766 #endif /*SUPPORT_TLS*/
768 done = TRUE; /* so far so good; have response to HELO */
770 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
772 /* For now, transport_filter by cutthrough-delivery is not supported */
773 /* Need proper integration with the proper transport mechanism. */
774 if (cutthrough_delivery)
776 if (addr->transport->filter_command)
778 cutthrough_delivery= FALSE;
779 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
784 cutthrough_delivery= FALSE;
785 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
794 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
796 /* Failure to accept HELO is cached; this blocks the whole domain for all
797 senders. I/O errors and defer responses are not cached. */
801 *failure_ptr = US"mail"; /* At or before MAIL */
802 if (errno == 0 && responsebuffer[0] == '5')
804 setflag(addr, af_verify_nsfail);
805 new_domain_record.result = ccache_reject;
809 /* If we haven't authenticated, but are required to, give up. */
812 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
813 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
815 /* Copy AUTH info for logging */
816 ( (addr->authenticator = client_authenticator),
817 (addr->auth_id = client_authenticated_id),
819 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
820 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
823 ( (addr->auth_sndr = client_authenticated_sender),
825 /* Send the MAIL command */
826 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
827 from_address, responsebuffer) >= 0)
830 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
833 deliver_host = deliver_host_address = NULL;
834 deliver_domain = save_deliver_domain;
836 /* If the host does not accept MAIL FROM:<>, arrange to cache this
837 information, but again, don't record anything for an I/O error or a defer. Do
838 not cache rejections of MAIL when a non-empty sender has been used, because
839 that blocks the whole domain for all senders. */
843 *failure_ptr = US"mail"; /* At or before MAIL */
844 if (errno == 0 && responsebuffer[0] == '5')
846 setflag(addr, af_verify_nsfail);
847 if (from_address[0] == 0)
848 new_domain_record.result = ccache_reject_mfnull;
852 /* Otherwise, proceed to check a "random" address (if required), then the
853 given address, and the postmaster address (if required). Between each check,
854 issue RSET, because some servers accept only one recipient after MAIL
857 Before doing this, set the result in the domain cache record to "accept",
858 unless its previous value was ccache_reject_mfnull. In that case, the domain
859 rejects MAIL FROM:<> and we want to continue to remember that. When that is
860 the case, we have got here only in the case of a recipient verification with
861 a non-null sender. */
865 new_domain_record.result =
866 (old_domain_cache_result == ccache_reject_mfnull)?
867 ccache_reject_mfnull: ccache_accept;
869 /* Do the random local part check first */
871 if (random_local_part != NULL)
873 uschar randombuffer[1024];
875 smtp_write_command(&outblock, FALSE,
876 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
877 addr->domain) >= 0 &&
878 smtp_read_response(&inblock, randombuffer,
879 sizeof(randombuffer), '2', callout);
881 /* Remember when we last did a random test */
883 new_domain_record.random_stamp = time(NULL);
885 /* If accepted, we aren't going to do any further tests below. */
888 new_domain_record.random_result = ccache_accept;
890 /* Otherwise, cache a real negative response, and get back to the right
891 state to send RCPT. Unless there's some problem such as a dropped
892 connection, we expect to succeed, because the commands succeeded above. */
896 if (randombuffer[0] == '5')
897 new_domain_record.random_result = ccache_reject;
900 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
901 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
904 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
905 from_address) >= 0 &&
906 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
909 else done = FALSE; /* Some timeout/connection problem */
912 /* If the host is accepting all local parts, as determined by the "random"
913 check, we don't need to waste time doing any further checking. */
915 if (new_domain_record.random_result != ccache_accept && done)
917 /* Get the rcpt_include_affixes flag from the transport if there is one,
918 but assume FALSE if there is not. */
921 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
922 transport_rcpt_address(addr,
923 (addr->transport == NULL)? FALSE :
924 addr->transport->rcpt_include_affixes)) >= 0 &&
925 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
929 new_address_record.result = ccache_accept;
930 else if (errno == 0 && responsebuffer[0] == '5')
932 *failure_ptr = US"recipient";
933 new_address_record.result = ccache_reject;
936 /* Do postmaster check if requested; if a full check is required, we
937 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
939 if (done && pm_mailfrom != NULL)
941 /*XXX not suitable for cutthrough - sequencing problems */
942 cutthrough_delivery= FALSE;
943 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
946 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
947 smtp_read_response(&inblock, responsebuffer,
948 sizeof(responsebuffer), '2', callout) &&
950 smtp_write_command(&outblock, FALSE,
951 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
952 smtp_read_response(&inblock, responsebuffer,
953 sizeof(responsebuffer), '2', callout) &&
955 /* First try using the current domain */
958 smtp_write_command(&outblock, FALSE,
959 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
960 smtp_read_response(&inblock, responsebuffer,
961 sizeof(responsebuffer), '2', callout)
966 /* If that doesn't work, and a full check is requested,
967 try without the domain. */
970 (options & vopt_callout_fullpm) != 0 &&
971 smtp_write_command(&outblock, FALSE,
972 "RCPT TO:<postmaster>\r\n") >= 0 &&
973 smtp_read_response(&inblock, responsebuffer,
974 sizeof(responsebuffer), '2', callout)
977 /* Sort out the cache record */
979 new_domain_record.postmaster_stamp = time(NULL);
982 new_domain_record.postmaster_result = ccache_accept;
983 else if (errno == 0 && responsebuffer[0] == '5')
985 *failure_ptr = US"postmaster";
986 setflag(addr, af_verify_pmfail);
987 new_domain_record.postmaster_result = ccache_reject;
990 } /* Random not accepted */
991 } /* MAIL FROM: accepted */
993 /* For any failure of the main check, other than a negative response, we just
994 close the connection and carry on. We can identify a negative response by the
995 fact that errno is zero. For I/O errors it will be non-zero
997 Set up different error texts for logging and for sending back to the caller
998 as an SMTP response. Log in all cases, using a one-line format. For sender
999 callouts, give a full response to the caller, but for recipient callouts,
1000 don't give the IP address because this may be an internal host whose identity
1001 is not to be widely broadcast. */
1005 if (errno == ETIMEDOUT)
1007 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1010 else if (errno == 0)
1012 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1015 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1016 big_buffer, host->name, host->address,
1017 string_printing(responsebuffer));
1019 addr->user_message = is_recipient?
1020 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1022 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1023 host->address, big_buffer, responsebuffer);
1025 /* Hard rejection ends the process */
1027 if (responsebuffer[0] == '5') /* Address rejected */
1035 /* End the SMTP conversation and close the connection. */
1037 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
1038 and we have no cutthrough conn so far
1039 here is where we want to leave the conn open */
1040 if ( cutthrough_delivery
1043 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1044 && !random_local_part
1046 && cutthrough_fd < 0
1049 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
1050 cutthrough_addr = *addr; /* Save the address_item for later logging */
1051 cutthrough_addr.next = NULL;
1052 cutthrough_addr.host_used = store_get(sizeof(host_item));
1053 *(cutthrough_addr.host_used) = *host;
1055 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
1056 ctblock.buffer = ctbuffer;
1057 ctblock.buffersize = sizeof(ctbuffer);
1058 ctblock.ptr = ctbuffer;
1059 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1060 ctblock.sock = cutthrough_fd;
1064 /* Ensure no cutthrough on multiple address verifies */
1065 if (options & vopt_callout_recipsender)
1066 cancel_cutthrough_connection("multiple verify calls");
1067 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1070 tls_close(FALSE, TRUE);
1072 (void)close(inblock.sock);
1073 #ifdef EXPERIMENTAL_EVENT
1074 (void) event_raise(addr->transport->event_action,
1075 US"tcp:close", NULL);
1079 } /* Loop through all hosts, while !done */
1082 /* If we get here with done == TRUE, a successful callout happened, and yield
1083 will be set OK or FAIL according to the response to the RCPT command.
1084 Otherwise, we looped through the hosts but couldn't complete the business.
1085 However, there may be domain-specific information to cache in both cases.
1087 The value of the result field in the new_domain record is ccache_unknown if
1088 there was an error before or with MAIL FROM:, and errno was not zero,
1089 implying some kind of I/O error. We don't want to write the cache in that case.
1090 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1092 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1094 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1097 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1101 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1102 (int)sizeof(dbdata_callout_cache));
1103 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1104 " result=%d postmaster=%d random=%d\n",
1105 new_domain_record.result,
1106 new_domain_record.postmaster_result,
1107 new_domain_record.random_result);
1111 /* If a definite result was obtained for the callout, cache it unless caching
1116 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1118 if (dbm_file == NULL)
1119 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1120 if (dbm_file == NULL)
1122 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1126 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1127 (int)sizeof(dbdata_callout_cache_address));
1128 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1129 (new_address_record.result == ccache_accept)? "positive" : "negative");
1134 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1135 temporary error. If there was only one host, and a response was received, leave
1136 it alone if supplying details. Otherwise, give a generic response. */
1140 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1141 is_recipient? "recipient" : "sender");
1144 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1146 addr->user_message = (!smtp_return_error_details)? dullmsg :
1147 string_sprintf("%s for <%s>.\n"
1148 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1149 "they may be permanently unreachable from this server. In the latter case,\n%s",
1150 dullmsg, addr->address,
1152 "the address will never be accepted."
1154 "you need to change the address or create an MX record for its domain\n"
1155 "if it is supposed to be generally accessible from the Internet.\n"
1156 "Talk to your mail administrator for details.");
1158 /* Force a specific error code */
1160 addr->basic_errno = ERRNO_CALLOUTDEFER;
1163 /* Come here from within the cache-reading code on fast-track exit. */
1166 if (dbm_file != NULL) dbfn_close(dbm_file);
1172 /* Called after recipient-acl to get a cutthrough connection open when
1173 one was requested and a recipient-verify wasn't subsequently done.
1176 open_cutthrough_connection( address_item * addr )
1180 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1181 /* We must use a copy of the address for verification, because it might
1185 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1186 (void) verify_address(&addr2, NULL,
1187 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1188 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1190 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1196 /* Send given number of bytes from the buffer */
1198 cutthrough_send(int n)
1200 if(cutthrough_fd < 0)
1205 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1207 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1210 transport_count += n;
1211 ctblock.ptr= ctblock.buffer;
1215 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1222 _cutthrough_puts(uschar * cp, int n)
1226 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1227 if(!cutthrough_send(ctblock.buffersize))
1230 *ctblock.ptr++ = *cp++;
1235 /* Buffered output of counted data block. Return boolean success */
1237 cutthrough_puts(uschar * cp, int n)
1239 if (cutthrough_fd < 0) return TRUE;
1240 if (_cutthrough_puts(cp, n)) return TRUE;
1241 cancel_cutthrough_connection("transmit failed");
1247 _cutthrough_flush_send( void )
1249 int n= ctblock.ptr-ctblock.buffer;
1252 if(!cutthrough_send(n))
1258 /* Send out any bufferred output. Return boolean success. */
1260 cutthrough_flush_send( void )
1262 if (_cutthrough_flush_send()) return TRUE;
1263 cancel_cutthrough_connection("transmit failed");
1269 cutthrough_put_nl( void )
1271 return cutthrough_puts(US"\r\n", 2);
1275 /* Get and check response from cutthrough target */
1277 cutthrough_response(char expect, uschar ** copy)
1279 smtp_inblock inblock;
1280 uschar inbuffer[4096];
1281 uschar responsebuffer[4096];
1283 inblock.buffer = inbuffer;
1284 inblock.buffersize = sizeof(inbuffer);
1285 inblock.ptr = inbuffer;
1286 inblock.ptrend = inbuffer;
1287 inblock.sock = cutthrough_fd;
1288 /* this relies on (inblock.sock == tls_out.active) */
1289 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1290 cancel_cutthrough_connection("target timeout on read");
1295 *copy= cp= string_copy(responsebuffer);
1296 /* Trim the trailing end of line */
1297 cp += Ustrlen(responsebuffer);
1298 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1299 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1302 return responsebuffer[0];
1306 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1308 cutthrough_predata( void )
1310 if(cutthrough_fd < 0)
1313 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1314 cutthrough_puts(US"DATA\r\n", 6);
1315 cutthrough_flush_send();
1317 /* Assume nothing buffered. If it was it gets ignored. */
1318 return cutthrough_response('3', NULL) == '3';
1322 /* fd and use_crlf args only to match write_chunk() */
1324 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1327 while(s && (s2 = Ustrchr(s, '\n')))
1329 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1337 /* Buffered send of headers. Return success boolean. */
1338 /* Expands newlines to wire format (CR,NL). */
1339 /* Also sends header-terminating blank line. */
1341 cutthrough_headers_send( void )
1343 if(cutthrough_fd < 0)
1346 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1347 but having a separate buffered-output function (for now)
1349 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1351 if (!transport_headers_send(&cutthrough_addr, cutthrough_fd,
1352 cutthrough_addr.transport->add_headers, cutthrough_addr.transport->remove_headers,
1353 &cutthrough_write_chunk, TRUE,
1354 cutthrough_addr.transport->rewrite_rules, cutthrough_addr.transport->rewrite_existflags))
1357 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1363 close_cutthrough_connection( const char * why )
1365 if(cutthrough_fd >= 0)
1367 /* We could be sending this after a bunch of data, but that is ok as
1368 the only way to cancel the transfer in dataphase is to drop the tcp
1369 conn before the final dot.
1371 ctblock.ptr = ctbuffer;
1372 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1373 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1374 _cutthrough_flush_send();
1375 /* No wait for response */
1378 tls_close(FALSE, TRUE);
1380 (void)close(cutthrough_fd);
1382 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1384 ctblock.ptr = ctbuffer;
1388 cancel_cutthrough_connection( const char * why )
1390 close_cutthrough_connection(why);
1391 cutthrough_delivery= FALSE;
1397 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1398 Log an OK response as a transmission.
1399 Close the connection.
1400 Return smtp response-class digit.
1403 cutthrough_finaldot( void )
1405 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1407 /* Assume data finshed with new-line */
1408 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1409 return cutthrough_addr.message;
1411 switch(cutthrough_response('2', &cutthrough_addr.message))
1414 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1415 close_cutthrough_connection("delivered");
1419 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1423 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1429 return cutthrough_addr.message;
1434 /*************************************************
1435 * Copy error to toplevel address *
1436 *************************************************/
1438 /* This function is used when a verify fails or defers, to ensure that the
1439 failure or defer information is in the original toplevel address. This applies
1440 when an address is redirected to a single new address, and the failure or
1441 deferral happens to the child address.
1444 vaddr the verify address item
1445 addr the final address item
1448 Returns: the value of YIELD
1452 copy_error(address_item *vaddr, address_item *addr, int yield)
1456 vaddr->message = addr->message;
1457 vaddr->user_message = addr->user_message;
1458 vaddr->basic_errno = addr->basic_errno;
1459 vaddr->more_errno = addr->more_errno;
1460 vaddr->p.address_data = addr->p.address_data;
1461 copyflag(vaddr, addr, af_pass_message);
1469 /**************************************************
1470 * printf that automatically handles TLS if needed *
1471 ***************************************************/
1473 /* This function is used by verify_address() as a substitute for all fprintf()
1474 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1475 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1476 that assumes that we always use the smtp_out FILE* when not using TLS or the
1477 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1478 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1482 f the candidate FILE* to write to
1483 format format string
1484 ... optional arguments
1490 static void PRINTF_FUNCTION(2,3)
1491 respond_printf(FILE *f, const char *format, ...)
1495 va_start(ap, format);
1496 if (smtp_out && (f == smtp_out))
1497 smtp_vprintf(format, ap);
1499 vfprintf(f, format, ap);
1505 /*************************************************
1506 * Verify an email address *
1507 *************************************************/
1509 /* This function is used both for verification (-bv and at other times) and
1510 address testing (-bt), which is indicated by address_test_mode being set.
1513 vaddr contains the address to verify; the next field in this block
1515 f if not NULL, write the result to this file
1516 options various option bits:
1517 vopt_fake_sender => this sender verify is not for the real
1518 sender (it was verify=sender=xxxx or an address from a
1519 header line) - rewriting must not change sender_address
1520 vopt_is_recipient => this is a recipient address, otherwise
1521 it's a sender address - this affects qualification and
1522 rewriting and messages from callouts
1523 vopt_qualify => qualify an unqualified address; else error
1524 vopt_expn => called from SMTP EXPN command
1525 vopt_success_on_redirect => when a new address is generated
1526 the verification instantly succeeds
1528 These ones are used by do_callout() -- the options variable
1531 vopt_callout_fullpm => if postmaster check, do full one
1532 vopt_callout_no_cache => don't use callout cache
1533 vopt_callout_random => do the "random" thing
1534 vopt_callout_recipsender => use real sender for recipient
1535 vopt_callout_recippmaster => use postmaster for recipient
1537 callout if > 0, specifies that callout is required, and gives timeout
1538 for individual commands
1539 callout_overall if > 0, gives overall timeout for the callout function;
1540 if < 0, a default is used (see do_callout())
1541 callout_connect the connection timeout for callouts
1542 se_mailfrom when callout is requested to verify a sender, use this
1543 in MAIL FROM; NULL => ""
1544 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1545 thing and use this as the sender address (may be "")
1547 routed if not NULL, set TRUE if routing succeeded, so we can
1548 distinguish between routing failed and callout failed
1550 Returns: OK address verified
1551 FAIL address failed to verify
1552 DEFER can't tell at present
1556 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1557 int callout_overall, int callout_connect, uschar *se_mailfrom,
1558 uschar *pm_mailfrom, BOOL *routed)
1561 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1562 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1563 BOOL expn = (options & vopt_expn) != 0;
1564 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1567 int verify_type = expn? v_expn :
1568 address_test_mode? v_none :
1569 is_recipient? v_recipient : v_sender;
1570 address_item *addr_list;
1571 address_item *addr_new = NULL;
1572 address_item *addr_remote = NULL;
1573 address_item *addr_local = NULL;
1574 address_item *addr_succeed = NULL;
1575 uschar **failure_ptr = is_recipient?
1576 &recipient_verify_failure : &sender_verify_failure;
1577 uschar *ko_prefix, *cr;
1578 uschar *address = vaddr->address;
1579 uschar *save_sender;
1580 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1582 /* Clear, just in case */
1584 *failure_ptr = NULL;
1586 /* Set up a prefix and suffix for error message which allow us to use the same
1587 output statements both in EXPN mode (where an SMTP response is needed) and when
1588 debugging with an output file. */
1592 ko_prefix = US"553 ";
1595 else ko_prefix = cr = US"";
1597 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1599 if (parse_find_at(address) == NULL)
1601 if ((options & vopt_qualify) == 0)
1604 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1605 ko_prefix, address, cr);
1606 *failure_ptr = US"qualify";
1609 address = rewrite_address_qualify(address, is_recipient);
1614 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1615 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1618 /* Rewrite and report on it. Clear the domain and local part caches - these
1619 may have been set by domains and local part tests during an ACL. */
1621 if (global_rewrite_rules != NULL)
1623 uschar *old = address;
1624 address = rewrite_address(address, is_recipient, FALSE,
1625 global_rewrite_rules, rewrite_existflags);
1628 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1629 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1630 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1634 /* If this is the real sender address, we must update sender_address at
1635 this point, because it may be referred to in the routers. */
1637 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1638 sender_address = address;
1640 /* If the address was rewritten to <> no verification can be done, and we have
1641 to return OK. This rewriting is permitted only for sender addresses; for other
1642 addresses, such rewriting fails. */
1644 if (address[0] == 0) return OK;
1646 /* Flip the legacy TLS-related variables over to the outbound set in case
1647 they're used in the context of a transport used by verification. Reset them
1648 at exit from this routine. */
1650 tls_modify_variables(&tls_out);
1652 /* Save a copy of the sender address for re-instating if we change it to <>
1653 while verifying a sender address (a nice bit of self-reference there). */
1655 save_sender = sender_address;
1657 /* Update the address structure with the possibly qualified and rewritten
1658 address. Set it up as the starting address on the chain of new addresses. */
1660 vaddr->address = address;
1663 /* We need a loop, because an address can generate new addresses. We must also
1664 cope with generated pipes and files at the top level. (See also the code and
1665 comment in deliver.c.) However, it is usually the case that the router for
1666 user's .forward files has its verify flag turned off.
1668 If an address generates more than one child, the loop is used only when
1669 full_info is set, and this can only be set locally. Remote enquiries just get
1670 information about the top level address, not anything that it generated. */
1672 while (addr_new != NULL)
1675 address_item *addr = addr_new;
1677 addr_new = addr->next;
1682 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1683 debug_printf("Considering %s\n", addr->address);
1686 /* Handle generated pipe, file or reply addresses. We don't get these
1687 when handling EXPN, as it does only one level of expansion. */
1689 if (testflag(addr, af_pfr))
1696 if (addr->address[0] == '>')
1698 allow = testflag(addr, af_allow_reply);
1699 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1703 allow = (addr->address[0] == '|')?
1704 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1705 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1708 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1709 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1710 "%s\n", addr->message);
1712 fprintf(f, "\n transport = %s\n", addr->transport->name);
1714 fprintf(f, " *** forbidden ***\n");
1719 /* Just in case some router parameter refers to it. */
1721 return_path = (addr->p.errors_address != NULL)?
1722 addr->p.errors_address : sender_address;
1724 /* Split the address into domain and local part, handling the %-hack if
1725 necessary, and then route it. While routing a sender address, set
1726 $sender_address to <> because that is what it will be if we were trying to
1727 send a bounce to the sender. */
1729 if (routed != NULL) *routed = FALSE;
1730 if ((rc = deliver_split_address(addr)) == OK)
1732 if (!is_recipient) sender_address = null_sender;
1733 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1734 &addr_succeed, verify_type);
1735 sender_address = save_sender; /* Put back the real sender */
1738 /* If routing an address succeeded, set the flag that remembers, for use when
1739 an ACL cached a sender verify (in case a callout fails). Then if routing set
1740 up a list of hosts or the transport has a host list, and the callout option
1741 is set, and we aren't in a host checking run, do the callout verification,
1742 and set another flag that notes that a callout happened. */
1746 if (routed != NULL) *routed = TRUE;
1749 host_item *host_list = addr->host_list;
1751 /* Make up some data for use in the case where there is no remote
1754 transport_feedback tf = {
1755 NULL, /* interface (=> any) */
1756 US"smtp", /* port */
1757 US"smtp", /* protocol */
1759 US"$smtp_active_hostname", /* helo_data */
1760 FALSE, /* hosts_override */
1761 FALSE, /* hosts_randomize */
1762 FALSE, /* gethostbyname */
1763 TRUE, /* qualify_single */
1764 FALSE /* search_parents */
1767 /* If verification yielded a remote transport, we want to use that
1768 transport's options, so as to mimic what would happen if we were really
1769 sending a message to this address. */
1771 if (addr->transport != NULL && !addr->transport->info->local)
1773 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1775 /* If the transport has hosts and the router does not, or if the
1776 transport is configured to override the router's hosts, we must build a
1777 host list of the transport's hosts, and find the IP addresses */
1779 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1782 uschar *save_deliver_domain = deliver_domain;
1783 uschar *save_deliver_localpart = deliver_localpart;
1785 host_list = NULL; /* Ignore the router's hosts */
1787 deliver_domain = addr->domain;
1788 deliver_localpart = addr->local_part;
1789 s = expand_string(tf.hosts);
1790 deliver_domain = save_deliver_domain;
1791 deliver_localpart = save_deliver_localpart;
1795 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1796 "\"%s\" in %s transport for callout: %s", tf.hosts,
1797 addr->transport->name, expand_string_message);
1802 uschar *canonical_name;
1803 host_item *host, *nexthost;
1804 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1806 /* Just ignore failures to find a host address. If we don't manage
1807 to find any addresses, the callout will defer. Note that more than
1808 one address may be found for a single host, which will result in
1809 additional host items being inserted into the chain. Hence we must
1810 save the next host first. */
1812 flags = HOST_FIND_BY_A;
1813 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1814 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1816 for (host = host_list; host != NULL; host = nexthost)
1818 nexthost = host->next;
1819 if (tf.gethostbyname ||
1820 string_is_ip_address(host->name, NULL) != 0)
1821 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1824 uschar * d_request = NULL, * d_require = NULL;
1825 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
1827 smtp_transport_options_block * ob =
1828 (smtp_transport_options_block *)
1829 addr->transport->options_block;
1830 d_request = ob->dnssec_request_domains;
1831 d_require = ob->dnssec_require_domains;
1834 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1835 d_request, d_require, &canonical_name, NULL);
1842 /* Can only do a callout if we have at least one host! If the callout
1843 fails, it will have set ${sender,recipient}_verify_failure. */
1845 if (host_list != NULL)
1847 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1848 if (host_checking && !host_checking_callout)
1851 debug_printf("... callout omitted by default when host testing\n"
1852 "(Use -bhc if you want the callouts to happen.)\n");
1857 deliver_set_expansions(addr);
1859 verify_mode = is_recipient ? US"R" : US"S";
1860 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1861 callout_connect, options, se_mailfrom, pm_mailfrom);
1867 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1868 "transport provided a host list\n");
1873 /* Otherwise, any failure is a routing failure */
1875 else *failure_ptr = US"route";
1877 /* A router may return REROUTED if it has set up a child address as a result
1878 of a change of domain name (typically from widening). In this case we always
1879 want to continue to verify the new child. */
1881 if (rc == REROUTED) continue;
1883 /* Handle hard failures */
1890 address_item *p = addr->parent;
1892 respond_printf(f, "%s%s %s", ko_prefix,
1893 full_info? addr->address : address,
1894 address_test_mode? "is undeliverable" : "failed to verify");
1895 if (!expn && admin_user)
1897 if (addr->basic_errno > 0)
1898 respond_printf(f, ": %s", strerror(addr->basic_errno));
1899 if (addr->message != NULL)
1900 respond_printf(f, ": %s", addr->message);
1903 /* Show parents iff doing full info */
1905 if (full_info) while (p != NULL)
1907 respond_printf(f, "%s\n <-- %s", cr, p->address);
1910 respond_printf(f, "%s\n", cr);
1912 cancel_cutthrough_connection("routing hard fail");
1916 yield = copy_error(vaddr, addr, FAIL);
1924 else if (rc == DEFER)
1929 address_item *p = addr->parent;
1930 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1931 full_info? addr->address : address);
1932 if (!expn && admin_user)
1934 if (addr->basic_errno > 0)
1935 respond_printf(f, ": %s", strerror(addr->basic_errno));
1936 if (addr->message != NULL)
1937 respond_printf(f, ": %s", addr->message);
1938 else if (addr->basic_errno <= 0)
1939 respond_printf(f, ": unknown error");
1942 /* Show parents iff doing full info */
1944 if (full_info) while (p != NULL)
1946 respond_printf(f, "%s\n <-- %s", cr, p->address);
1949 respond_printf(f, "%s\n", cr);
1951 cancel_cutthrough_connection("routing soft fail");
1955 yield = copy_error(vaddr, addr, DEFER);
1958 else if (yield == OK) yield = DEFER;
1961 /* If we are handling EXPN, we do not want to continue to route beyond
1962 the top level (whose address is in "address"). */
1966 uschar *ok_prefix = US"250-";
1967 if (addr_new == NULL)
1969 if (addr_local == NULL && addr_remote == NULL)
1970 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1972 respond_printf(f, "250 <%s>\r\n", address);
1974 else while (addr_new != NULL)
1976 address_item *addr2 = addr_new;
1977 addr_new = addr2->next;
1978 if (addr_new == NULL) ok_prefix = US"250 ";
1979 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1985 /* Successful routing other than EXPN. */
1989 /* Handle successful routing when short info wanted. Otherwise continue for
1990 other (generated) addresses. Short info is the operational case. Full info
1991 can be requested only when debug_selector != 0 and a file is supplied.
1993 There is a conflict between the use of aliasing as an alternate email
1994 address, and as a sort of mailing list. If an alias turns the incoming
1995 address into just one address (e.g. J.Caesar->jc44) you may well want to
1996 carry on verifying the generated address to ensure it is valid when
1997 checking incoming mail. If aliasing generates multiple addresses, you
1998 probably don't want to do this. Exim therefore treats the generation of
1999 just a single new address as a special case, and continues on to verify the
2000 generated address. */
2002 if (!full_info && /* Stop if short info wanted AND */
2003 (((addr_new == NULL || /* No new address OR */
2004 addr_new->next != NULL || /* More than one new address OR */
2005 testflag(addr_new, af_pfr))) /* New address is pfr */
2007 (addr_new != NULL && /* At least one new address AND */
2008 success_on_redirect))) /* success_on_redirect is set */
2010 if (f != NULL) fprintf(f, "%s %s\n", address,
2011 address_test_mode? "is deliverable" : "verified");
2013 /* If we have carried on to verify a child address, we want the value
2014 of $address_data to be that of the child */
2016 vaddr->p.address_data = addr->p.address_data;
2021 } /* Loop for generated addresses */
2023 /* Display the full results of the successful routing, including any generated
2024 addresses. Control gets here only when full_info is set, which requires f not
2025 to be NULL, and this occurs only when a top-level verify is called with the
2026 debugging switch on.
2028 If there are no local and no remote addresses, and there were no pipes, files,
2029 or autoreplies, and there were no errors or deferments, the message is to be
2030 discarded, usually because of the use of :blackhole: in an alias file. */
2032 if (allok && addr_local == NULL && addr_remote == NULL)
2034 fprintf(f, "mail to %s is discarded\n", address);
2038 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2040 while (addr_list != NULL)
2042 address_item *addr = addr_list;
2043 address_item *p = addr->parent;
2044 addr_list = addr->next;
2046 fprintf(f, "%s", CS addr->address);
2047 #ifdef EXPERIMENTAL_SRS
2048 if(addr->p.srs_sender)
2049 fprintf(f, " [srs = %s]", addr->p.srs_sender);
2052 /* If the address is a duplicate, show something about it. */
2054 if (!testflag(addr, af_pfr))
2057 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2058 fprintf(f, " [duplicate, would not be delivered]");
2059 else tree_add_duplicate(addr->unique, addr);
2062 /* Now show its parents */
2066 fprintf(f, "\n <-- %s", p->address);
2071 /* Show router, and transport */
2073 fprintf(f, "router = %s, ", addr->router->name);
2074 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2075 addr->transport->name);
2077 /* Show any hosts that are set up by a router unless the transport
2078 is going to override them; fiddle a bit to get a nice format. */
2080 if (addr->host_list != NULL && addr->transport != NULL &&
2081 !addr->transport->overrides_hosts)
2086 for (h = addr->host_list; h != NULL; h = h->next)
2088 int len = Ustrlen(h->name);
2089 if (len > maxlen) maxlen = len;
2090 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2091 if (len > maxaddlen) maxaddlen = len;
2093 for (h = addr->host_list; h != NULL; h = h->next)
2095 int len = Ustrlen(h->name);
2096 fprintf(f, " host %s ", h->name);
2097 while (len++ < maxlen) fprintf(f, " ");
2098 if (h->address != NULL)
2100 fprintf(f, "[%s] ", h->address);
2101 len = Ustrlen(h->address);
2103 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2105 fprintf(f, "[unknown] ");
2109 while (len++ < maxaddlen) fprintf(f," ");
2110 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2111 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2112 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2119 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2120 the -bv or -bt case). */
2123 tls_modify_variables(&tls_in);
2131 /*************************************************
2132 * Check headers for syntax errors *
2133 *************************************************/
2135 /* This function checks those header lines that contain addresses, and verifies
2136 that all the addresses therein are syntactially correct.
2139 msgptr where to put an error message
2146 verify_check_headers(uschar **msgptr)
2152 for (h = header_list; h != NULL && yield == OK; h = h->next)
2154 if (h->type != htype_from &&
2155 h->type != htype_reply_to &&
2156 h->type != htype_sender &&
2157 h->type != htype_to &&
2158 h->type != htype_cc &&
2159 h->type != htype_bcc)
2162 colon = Ustrchr(h->text, ':');
2164 while (isspace(*s)) s++;
2166 /* Loop for multiple addresses in the header, enabling group syntax. Note
2167 that we have to reset this after the header has been scanned. */
2169 parse_allow_group = TRUE;
2173 uschar *ss = parse_find_address_end(s, FALSE);
2174 uschar *recipient, *errmess;
2175 int terminator = *ss;
2176 int start, end, domain;
2178 /* Temporarily terminate the string at this point, and extract the
2179 operative address within, allowing group syntax. */
2182 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2185 /* Permit an unqualified address only if the message is local, or if the
2186 sending host is configured to be permitted to send them. */
2188 if (recipient != NULL && domain == 0)
2190 if (h->type == htype_from || h->type == htype_sender)
2192 if (!allow_unqualified_sender) recipient = NULL;
2196 if (!allow_unqualified_recipient) recipient = NULL;
2198 if (recipient == NULL) errmess = US"unqualified address not permitted";
2201 /* It's an error if no address could be extracted, except for the special
2202 case of an empty address. */
2204 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2206 uschar *verb = US"is";
2211 /* Arrange not to include any white space at the end in the
2212 error message or the header name. */
2214 while (t > s && isspace(t[-1])) t--;
2215 while (tt > h->text && isspace(tt[-1])) tt--;
2217 /* Add the address that failed to the error message, since in a
2218 header with very many addresses it is sometimes hard to spot
2219 which one is at fault. However, limit the amount of address to
2220 quote - cases have been seen where, for example, a missing double
2221 quote in a humungous To: header creates an "address" that is longer
2222 than string_sprintf can handle. */
2231 *msgptr = string_printing(
2232 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2233 errmess, tt - h->text, h->text, verb, len, s));
2236 break; /* Out of address loop */
2239 /* Advance to the next address */
2241 s = ss + (terminator? 1:0);
2242 while (isspace(*s)) s++;
2243 } /* Next address */
2245 parse_allow_group = FALSE;
2246 parse_found_group = FALSE;
2247 } /* Next header unless yield has been set FALSE */
2253 /*************************************************
2254 * Check header names for 8-bit characters *
2255 *************************************************/
2257 /* This function checks for invalid charcters in header names. See
2258 RFC 5322, 2.2. and RFC 6532, 3.
2261 msgptr where to put an error message
2268 verify_check_header_names_ascii(uschar **msgptr)
2273 for (h = header_list; h != NULL; h = h->next)
2275 colon = Ustrchr(h->text, ':');
2276 for(s = h->text; s < colon; s++)
2278 if ((*s < 33) || (*s > 126))
2280 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2281 colon - h->text, h->text);
2289 /*************************************************
2290 * Check for blind recipients *
2291 *************************************************/
2293 /* This function checks that every (envelope) recipient is mentioned in either
2294 the To: or Cc: header lines, thus detecting blind carbon copies.
2296 There are two ways of scanning that could be used: either scan the header lines
2297 and tick off the recipients, or scan the recipients and check the header lines.
2298 The original proposed patch did the former, but I have chosen to do the latter,
2299 because (a) it requires no memory and (b) will use fewer resources when there
2300 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2303 Returns: OK if there are no blind recipients
2304 FAIL if there is at least one blind recipient
2308 verify_check_notblind(void)
2311 for (i = 0; i < recipients_count; i++)
2315 uschar *address = recipients_list[i].address;
2317 for (h = header_list; !found && h != NULL; h = h->next)
2321 if (h->type != htype_to && h->type != htype_cc) continue;
2323 colon = Ustrchr(h->text, ':');
2325 while (isspace(*s)) s++;
2327 /* Loop for multiple addresses in the header, enabling group syntax. Note
2328 that we have to reset this after the header has been scanned. */
2330 parse_allow_group = TRUE;
2334 uschar *ss = parse_find_address_end(s, FALSE);
2335 uschar *recipient,*errmess;
2336 int terminator = *ss;
2337 int start, end, domain;
2339 /* Temporarily terminate the string at this point, and extract the
2340 operative address within, allowing group syntax. */
2343 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2346 /* If we found a valid recipient that has a domain, compare it with the
2347 envelope recipient. Local parts are compared case-sensitively, domains
2348 case-insensitively. By comparing from the start with length "domain", we
2349 include the "@" at the end, which ensures that we are comparing the whole
2350 local part of each address. */
2352 if (recipient != NULL && domain != 0)
2354 found = Ustrncmp(recipient, address, domain) == 0 &&
2355 strcmpic(recipient + domain, address + domain) == 0;
2359 /* Advance to the next address */
2361 s = ss + (terminator? 1:0);
2362 while (isspace(*s)) s++;
2363 } /* Next address */
2365 parse_allow_group = FALSE;
2366 parse_found_group = FALSE;
2367 } /* Next header (if found is false) */
2369 if (!found) return FAIL;
2370 } /* Next recipient */
2377 /*************************************************
2378 * Find if verified sender *
2379 *************************************************/
2381 /* Usually, just a single address is verified as the sender of the message.
2382 However, Exim can be made to verify other addresses as well (often related in
2383 some way), and this is useful in some environments. There may therefore be a
2384 chain of such addresses that have previously been tested. This function finds
2385 whether a given address is on the chain.
2387 Arguments: the address to be verified
2388 Returns: pointer to an address item, or NULL
2392 verify_checked_sender(uschar *sender)
2395 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2396 if (Ustrcmp(sender, addr->address) == 0) break;
2404 /*************************************************
2405 * Get valid header address *
2406 *************************************************/
2408 /* Scan the originator headers of the message, looking for an address that
2409 verifies successfully. RFC 822 says:
2411 o The "Sender" field mailbox should be sent notices of
2412 any problems in transport or delivery of the original
2413 messages. If there is no "Sender" field, then the
2414 "From" field mailbox should be used.
2416 o If the "Reply-To" field exists, then the reply should
2417 go to the addresses indicated in that field and not to
2418 the address(es) indicated in the "From" field.
2420 So we check a Sender field if there is one, else a Reply_to field, else a From
2421 field. As some strange messages may have more than one of these fields,
2422 especially if they are resent- fields, check all of them if there is more than
2426 user_msgptr points to where to put a user error message
2427 log_msgptr points to where to put a log error message
2428 callout timeout for callout check (passed to verify_address())
2429 callout_overall overall callout timeout (ditto)
2430 callout_connect connect callout timeout (ditto)
2431 se_mailfrom mailfrom for verify; NULL => ""
2432 pm_mailfrom sender for pm callout check (passed to verify_address())
2433 options callout options (passed to verify_address())
2434 verrno where to put the address basic_errno
2436 If log_msgptr is set to something without setting user_msgptr, the caller
2437 normally uses log_msgptr for both things.
2439 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2440 FAIL is given if no appropriate headers are found
2444 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2445 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2446 uschar *pm_mailfrom, int options, int *verrno)
2448 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2453 for (i = 0; i < 3 && !done; i++)
2456 for (h = header_list; h != NULL && !done; h = h->next)
2458 int terminator, new_ok;
2459 uschar *s, *ss, *endname;
2461 if (h->type != header_types[i]) continue;
2462 s = endname = Ustrchr(h->text, ':') + 1;
2464 /* Scan the addresses in the header, enabling group syntax. Note that we
2465 have to reset this after the header has been scanned. */
2467 parse_allow_group = TRUE;
2471 address_item *vaddr;
2473 while (isspace(*s) || *s == ',') s++;
2474 if (*s == 0) break; /* End of header */
2476 ss = parse_find_address_end(s, FALSE);
2478 /* The terminator is a comma or end of header, but there may be white
2479 space preceding it (including newline for the last address). Move back
2480 past any white space so we can check against any cached envelope sender
2481 address verifications. */
2483 while (isspace(ss[-1])) ss--;
2487 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2488 (int)(endname - h->text), h->text, s);
2490 /* See if we have already verified this address as an envelope sender,
2491 and if so, use the previous answer. */
2493 vaddr = verify_checked_sender(s);
2495 if (vaddr != NULL && /* Previously checked */
2496 (callout <= 0 || /* No callout needed; OR */
2497 vaddr->special_action > 256)) /* Callout was done */
2499 new_ok = vaddr->special_action & 255;
2500 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2501 *ss = terminator; /* Restore shortened string */
2504 /* Otherwise we run the verification now. We must restore the shortened
2505 string before running the verification, so the headers are correct, in
2506 case there is any rewriting. */
2510 int start, end, domain;
2511 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2516 /* If we found an empty address, just carry on with the next one, but
2517 kill the message. */
2519 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2526 /* If verification failed because of a syntax error, fail this
2527 function, and ensure that the failing address gets added to the error
2530 if (address == NULL)
2533 while (ss > s && isspace(ss[-1])) ss--;
2534 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2535 "scanning for sender: %s in \"%.*s\"",
2536 endname - h->text, h->text, *log_msgptr, ss - s, s);
2542 /* Else go ahead with the sender verification. But it isn't *the*
2543 sender of the message, so set vopt_fake_sender to stop sender_address
2544 being replaced after rewriting or qualification. */
2548 vaddr = deliver_make_addr(address, FALSE);
2549 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2550 callout, callout_overall, callout_connect, se_mailfrom,
2555 /* We now have the result, either newly found, or cached. If we are
2556 giving out error details, set a specific user error. This means that the
2557 last of these will be returned to the user if all three fail. We do not
2558 set a log message - the generic one below will be used. */
2562 *verrno = vaddr->basic_errno;
2563 if (smtp_return_error_details)
2565 *user_msgptr = string_sprintf("Rejected after DATA: "
2566 "could not verify \"%.*s\" header address\n%s: %s",
2567 endname - h->text, h->text, vaddr->address, vaddr->message);
2571 /* Success or defer */
2580 if (new_ok == DEFER) yield = DEFER;
2582 /* Move on to any more addresses in the header */
2585 } /* Next address */
2587 parse_allow_group = FALSE;
2588 parse_found_group = FALSE;
2589 } /* Next header, unless done */
2590 } /* Next header type unless done */
2592 if (yield == FAIL && *log_msgptr == NULL)
2593 *log_msgptr = US"there is no valid sender in any header line";
2595 if (yield == DEFER && *log_msgptr == NULL)
2596 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2604 /*************************************************
2605 * Get RFC 1413 identification *
2606 *************************************************/
2608 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2609 the timeout is set to zero, then the query is not done. There may also be lists
2610 of hosts and nets which are exempt. To guard against malefactors sending
2611 non-printing characters which could, for example, disrupt a message's headers,
2612 make sure the string consists of printing characters only.
2615 port the port to connect to; usually this is IDENT_PORT (113), but when
2616 running in the test harness with -bh a different value is used.
2620 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2624 verify_get_ident(int port)
2626 int sock, host_af, qlen;
2627 int received_sender_port, received_interface_port, n;
2629 uschar buffer[2048];
2631 /* Default is no ident. Check whether we want to do an ident check for this
2634 sender_ident = NULL;
2635 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2638 DEBUG(D_ident) debug_printf("doing ident callback\n");
2640 /* Set up a connection to the ident port of the remote host. Bind the local end
2641 to the incoming interface address. If the sender host address is an IPv6
2642 address, the incoming interface address will also be IPv6. */
2644 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2645 sock = ip_socket(SOCK_STREAM, host_af);
2646 if (sock < 0) return;
2648 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2650 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2655 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2658 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2660 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2661 sender_host_address);
2665 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2666 sender_host_address, strerror(errno));
2671 /* Construct and send the query. */
2673 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2674 qlen = Ustrlen(buffer);
2675 if (send(sock, buffer, qlen, 0) < 0)
2677 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2681 /* Read a response line. We put it into the rest of the buffer, using several
2682 recv() calls if necessary. */
2690 int size = sizeof(buffer) - (p - buffer);
2692 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2693 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2694 if (count <= 0) goto END_OFF; /* Read error or EOF */
2696 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2697 generous, and accept a plain \n terminator as well. The only illegal
2700 for (pp = p; pp < p + count; pp++)
2702 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2705 if (pp[-1] == '\r') pp--;
2707 goto GOT_DATA; /* Break out of both loops */
2711 /* Reached the end of the data without finding \n. Let the loop continue to
2712 read some more, if there is room. */
2719 /* We have received a line of data. Check it carefully. It must start with the
2720 same two port numbers that we sent, followed by data as defined by the RFC. For
2723 12345 , 25 : USERID : UNIX :root
2725 However, the amount of white space may be different to what we sent. In the
2726 "osname" field there may be several sub-fields, comma separated. The data we
2727 actually want to save follows the third colon. Some systems put leading spaces
2728 in it - we discard those. */
2730 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2731 &received_interface_port, &n) != 2 ||
2732 received_sender_port != sender_host_port ||
2733 received_interface_port != interface_port)
2736 p = buffer + qlen + n;
2737 while(isspace(*p)) p++;
2738 if (*p++ != ':') goto END_OFF;
2739 while(isspace(*p)) p++;
2740 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2742 while(isspace(*p)) p++;
2743 if (*p++ != ':') goto END_OFF;
2744 while (*p != 0 && *p != ':') p++;
2745 if (*p++ == 0) goto END_OFF;
2746 while(isspace(*p)) p++;
2747 if (*p == 0) goto END_OFF;
2749 /* The rest of the line is the data we want. We turn it into printing
2750 characters when we save it, so that it cannot mess up the format of any logging
2751 or Received: lines into which it gets inserted. We keep a maximum of 127
2754 sender_ident = string_printing(string_copyn(p, 127));
2755 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2765 /*************************************************
2766 * Match host to a single host-list item *
2767 *************************************************/
2769 /* This function compares a host (name or address) against a single item
2770 from a host list. The host name gets looked up if it is needed and is not
2771 already known. The function is called from verify_check_this_host() via
2772 match_check_list(), which is why most of its arguments are in a single block.
2775 arg the argument block (see below)
2776 ss the host-list item
2777 valueptr where to pass back looked up data, or NULL
2778 error for error message when returning ERROR
2781 host_name (a) the host name, or
2782 (b) NULL, implying use sender_host_name and
2783 sender_host_aliases, looking them up if required, or
2784 (c) the empty string, meaning that only IP address matches
2786 host_address the host address
2787 host_ipv4 the IPv4 address taken from an IPv6 one
2791 DEFER lookup deferred
2792 ERROR (a) failed to find the host name or IP address, or
2793 (b) unknown lookup type specified, or
2794 (c) host name encountered when only IP addresses are
2799 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2801 check_host_block *cb = (check_host_block *)arg;
2804 BOOL iplookup = FALSE;
2805 BOOL isquery = FALSE;
2806 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2811 /* Optimize for the special case when the pattern is "*". */
2813 if (*ss == '*' && ss[1] == 0) return OK;
2815 /* If the pattern is empty, it matches only in the case when there is no host -
2816 this can occur in ACL checking for SMTP input using the -bs option. In this
2817 situation, the host address is the empty string. */
2819 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2820 if (*ss == 0) return FAIL;
2822 /* If the pattern is precisely "@" then match against the primary host name,
2823 provided that host name matching is permitted; if it's "@[]" match against the
2824 local host's IP addresses. */
2830 if (isiponly) return ERROR;
2831 ss = primary_hostname;
2833 else if (Ustrcmp(ss, "@[]") == 0)
2835 ip_address_item *ip;
2836 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2837 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2842 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2843 a (possibly masked) comparision with the current IP address. */
2845 if (string_is_ip_address(ss, &maskoffset) != 0)
2846 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2848 /* The pattern is not an IP address. A common error that people make is to omit
2849 one component of an IPv4 address, either by accident, or believing that, for
2850 example, 1.2.3/24 is the same as 1.2.3.0/24, or 1.2.3 is the same as 1.2.3.0,
2851 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2852 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2853 ancient specification.) To aid in debugging these cases, we give a specific
2854 error if the pattern contains only digits and dots or contains a slash preceded
2855 only by digits and dots (a slash at the start indicates a file name and of
2856 course slashes may be present in lookups, but not preceded only by digits and
2859 for (t = ss; isdigit(*t) || *t == '.'; t++);
2860 if (*t == 0 || (*t == '/' && t != ss))
2862 *error = US"malformed IPv4 address or address mask";
2866 /* See if there is a semicolon in the pattern */
2868 semicolon = Ustrchr(ss, ';');
2870 /* If we are doing an IP address only match, then all lookups must be IP
2871 address lookups, even if there is no "net-". */
2875 iplookup = semicolon != NULL;
2878 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2879 a lookup on a masked IP network, in textual form. We obey this code even if we
2880 have already set iplookup, so as to skip over the "net-" prefix and to set the
2881 mask length. The net- stuff really only applies to single-key lookups where the
2882 key is implicit. For query-style lookups the key is specified in the query.
2883 From release 4.30, the use of net- for query style is no longer needed, but we
2884 retain it for backward compatibility. */
2886 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2889 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2890 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2891 iplookup = (*t++ == '-');
2895 /* Do the IP address lookup if that is indeed what we have */
2903 uschar *filename, *key, *result;
2906 /* Find the search type */
2908 search_type = search_findtype(t, semicolon - t);
2910 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2911 search_error_message);
2913 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2914 is no file name, and the "key" is just the query. For query-style with a file
2915 name, we have to fish the file off the start of the query. For a single-key
2916 lookup, the key is the current IP address, masked appropriately, and
2917 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2918 dot separators instead of colons, except when the lookup type is "iplsearch".
2921 if (mac_islookup(search_type, lookup_absfilequery))
2923 filename = semicolon + 1;
2925 while (*key != 0 && !isspace(*key)) key++;
2926 filename = string_copyn(filename, key - filename);
2927 while (isspace(*key)) key++;
2929 else if (mac_islookup(search_type, lookup_querystyle))
2932 key = semicolon + 1;
2934 else /* Single-key style */
2936 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2938 insize = host_aton(cb->host_address, incoming);
2939 host_mask(insize, incoming, mlen);
2940 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2942 filename = semicolon + 1;
2945 /* Now do the actual lookup; note that there is no search_close() because
2946 of the caching arrangements. */
2948 handle = search_open(filename, search_type, 0, NULL, NULL);
2949 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2950 search_error_message);
2951 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2952 if (valueptr != NULL) *valueptr = result;
2953 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2956 /* The pattern is not an IP address or network reference of any kind. That is,
2957 it is a host name pattern. If this is an IP only match, there's an error in the
2962 *error = US"cannot match host name in match_ip list";
2966 /* Check the characters of the pattern to see if they comprise only letters,
2967 digits, full stops, and hyphens (the constituents of domain names). Allow
2968 underscores, as they are all too commonly found. Sigh. Also, if
2969 allow_utf8_domains is set, allow top-bit characters. */
2971 for (t = ss; *t != 0; t++)
2972 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2973 (!allow_utf8_domains || *t < 128)) break;
2975 /* If the pattern is a complete domain name, with no fancy characters, look up
2976 its IP address and match against that. Note that a multi-homed host will add
2977 items to the chain. */
2988 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2989 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2992 for (hh = &h; hh != NULL; hh = hh->next)
2994 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2998 if (rc == HOST_FIND_AGAIN) return DEFER;
2999 *error = string_sprintf("failed to find IP address for %s", ss);
3003 /* Almost all subsequent comparisons require the host name, and can be done
3004 using the general string matching function. When this function is called for
3005 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3006 must use sender_host_name and its aliases, looking them up if necessary. */
3008 if (cb->host_name != NULL) /* Explicit host name given */
3009 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3012 /* Host name not given; in principle we need the sender host name and its
3013 aliases. However, for query-style lookups, we do not need the name if the
3014 query does not contain $sender_host_name. From release 4.23, a reference to
3015 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3018 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3021 int partial, affixlen, starflags, id;
3024 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3027 if (id < 0) /* Unknown lookup type */
3029 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3030 search_error_message, ss);
3033 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3038 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3041 case DEFER: return DEFER;
3042 default: return FAIL;
3046 /* Not a query-style lookup; must ensure the host name is present, and then we
3047 do a check on the name and all its aliases. */
3049 if (sender_host_name == NULL)
3051 HDEBUG(D_host_lookup)
3052 debug_printf("sender host name required, to match against %s\n", ss);
3053 if (host_lookup_failed || host_name_lookup() != OK)
3055 *error = string_sprintf("failed to find host name for %s",
3056 sender_host_address);;
3059 host_build_sender_fullhost();
3062 /* Match on the sender host name, using the general matching function */
3064 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3068 case DEFER: return DEFER;
3071 /* If there are aliases, try matching on them. */
3073 aliases = sender_host_aliases;
3074 while (*aliases != NULL)
3076 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3079 case DEFER: return DEFER;
3088 /*************************************************
3089 * Check a specific host matches a host list *
3090 *************************************************/
3092 /* This function is passed a host list containing items in a number of
3093 different formats and the identity of a host. Its job is to determine whether
3094 the given host is in the set of hosts defined by the list. The host name is
3095 passed as a pointer so that it can be looked up if needed and not already
3096 known. This is commonly the case when called from verify_check_host() to check
3097 an incoming connection. When called from elsewhere the host name should usually
3100 This function is now just a front end to match_check_list(), which runs common
3101 code for scanning a list. We pass it the check_host() function to perform a
3105 listptr pointer to the host list
3106 cache_bits pointer to cache for named lists, or NULL
3107 host_name the host name or NULL, implying use sender_host_name and
3108 sender_host_aliases, looking them up if required
3109 host_address the IP address
3110 valueptr if not NULL, data from a lookup is passed back here
3112 Returns: OK if the host is in the defined set
3113 FAIL if the host is not in the defined set,
3114 DEFER if a data lookup deferred (not a host lookup)
3116 If the host name was needed in order to make a comparison, and could not be
3117 determined from the IP address, the result is FAIL unless the item
3118 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3121 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
3122 uschar *host_name, uschar *host_address, uschar **valueptr)
3125 unsigned int *local_cache_bits = cache_bits;
3126 uschar *save_host_address = deliver_host_address;
3127 check_host_block cb;
3128 cb.host_name = host_name;
3129 cb.host_address = host_address;
3131 if (valueptr != NULL) *valueptr = NULL;
3133 /* If the host address starts off ::ffff: it is an IPv6 address in
3134 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3137 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3138 host_address + 7 : host_address;
3140 /* During the running of the check, put the IP address into $host_address. In
3141 the case of calls from the smtp transport, it will already be there. However,
3142 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3143 the safe side, any existing setting is preserved, though as I write this
3144 (November 2004) I can't see any cases where it is actually needed. */
3146 deliver_host_address = host_address;
3147 rc = match_check_list(
3148 listptr, /* the list */
3149 0, /* separator character */
3150 &hostlist_anchor, /* anchor pointer */
3151 &local_cache_bits, /* cache pointer */
3152 check_host, /* function for testing */
3153 &cb, /* argument for function */
3154 MCL_HOST, /* type of check */
3155 (host_address == sender_host_address)?
3156 US"host" : host_address, /* text for debugging */
3157 valueptr); /* where to pass back data */
3158 deliver_host_address = save_host_address;
3165 /*************************************************
3166 * Check the remote host matches a list *
3167 *************************************************/
3169 /* This is a front end to verify_check_this_host(), created because checking
3170 the remote host is a common occurrence. With luck, a good compiler will spot
3171 the tail recursion and optimize it. If there's no host address, this is
3172 command-line SMTP input - check against an empty string for the address.
3175 listptr pointer to the host list
3177 Returns: the yield of verify_check_this_host(),
3178 i.e. OK, FAIL, or DEFER
3182 verify_check_host(uschar **listptr)
3184 return verify_check_this_host(listptr, sender_host_cache, NULL,
3185 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3192 /*************************************************
3193 * Invert an IP address *
3194 *************************************************/
3196 /* Originally just used for DNS xBL lists, now also used for the
3197 reverse_ip expansion operator.
3200 buffer where to put the answer
3201 address the address to invert
3205 invert_address(uschar *buffer, uschar *address)
3208 uschar *bptr = buffer;
3210 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3211 to the IPv4 part only. */
3213 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3215 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3218 if (host_aton(address, bin) == 1)
3222 for (i = 0; i < 4; i++)
3224 sprintf(CS bptr, "%d.", x & 255);
3225 while (*bptr) bptr++;
3230 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3231 in any DNS black lists, and the format in which they will be looked up is
3232 unknown. This is just a guess. */
3238 for (j = 3; j >= 0; j--)
3241 for (i = 0; i < 8; i++)
3243 sprintf(CS bptr, "%x.", x & 15);
3244 while (*bptr) bptr++;
3251 /* Remove trailing period -- this is needed so that both arbitrary
3252 dnsbl keydomains and inverted addresses may be combined with the
3253 same format string, "%s.%s" */
3260 /*************************************************
3261 * Perform a single dnsbl lookup *
3262 *************************************************/
3264 /* This function is called from verify_check_dnsbl() below. It is also called
3265 recursively from within itself when domain and domain_txt are different
3266 pointers, in order to get the TXT record from the alternate domain.
3269 domain the outer dnsbl domain
3270 domain_txt alternate domain to lookup TXT record on success; when the
3271 same domain is to be used, domain_txt == domain (that is,
3272 the pointers must be identical, not just the text)
3273 keydomain the current keydomain (for debug message)
3274 prepend subdomain to lookup (like keydomain, but
3275 reversed if IP address)
3276 iplist the list of matching IP addresses, or NULL for "any"
3277 bitmask true if bitmask matching is wanted
3278 match_type condition for 'succeed' result
3279 0 => Any RR in iplist (=)
3280 1 => No RR in iplist (!=)
3281 2 => All RRs in iplist (==)
3282 3 => Some RRs not in iplist (!==)
3283 the two bits are defined as MT_NOT and MT_ALL
3284 defer_return what to return for a defer
3286 Returns: OK if lookup succeeded
3291 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3292 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3298 dnsbl_cache_block *cb;
3299 int old_pool = store_pool;
3300 uschar query[256]; /* DNS domain max length */
3302 /* Construct the specific query domainname */
3304 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3306 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3307 "(ignored): %s...", query);
3311 /* Look for this query in the cache. */
3313 t = tree_search(dnsbl_cache, query);
3315 /* If not cached from a previous lookup, we must do a DNS lookup, and
3316 cache the result in permanent memory. */
3320 store_pool = POOL_PERM;
3322 /* Set up a tree entry to cache the lookup */
3324 t = store_get(sizeof(tree_node) + Ustrlen(query));
3325 Ustrcpy(t->name, query);
3326 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3327 (void)tree_insertnode(&dnsbl_cache, t);
3329 /* Do the DNS loopup . */
3331 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3332 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3333 cb->text_set = FALSE;
3337 /* If the lookup succeeded, cache the RHS address. The code allows for
3338 more than one address - this was for complete generality and the possible
3339 use of A6 records. However, A6 records have been reduced to experimental
3340 status (August 2001) and may die out. So they may never get used at all,
3341 let alone in dnsbl records. However, leave the code here, just in case.
3343 Quite apart from one A6 RR generating multiple addresses, there are DNS
3344 lists that return more than one A record, so we must handle multiple
3345 addresses generated in that way as well. */
3347 if (cb->rc == DNS_SUCCEED)
3350 dns_address **addrp = &(cb->rhs);
3351 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3353 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3355 if (rr->type == T_A)
3357 dns_address *da = dns_address_from_rr(&dnsa, rr);
3361 while (da->next != NULL) da = da->next;
3362 addrp = &(da->next);
3367 /* If we didn't find any A records, change the return code. This can
3368 happen when there is a CNAME record but there are no A records for what
3371 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3374 store_pool = old_pool;
3377 /* Previous lookup was cached */
3381 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3385 /* We now have the result of the DNS lookup, either newly done, or cached
3386 from a previous call. If the lookup succeeded, check against the address
3387 list if there is one. This may be a positive equality list (introduced by
3388 "="), a negative equality list (introduced by "!="), a positive bitmask
3389 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3391 if (cb->rc == DNS_SUCCEED)
3393 dns_address *da = NULL;
3394 uschar *addlist = cb->rhs->address;
3396 /* For A and AAAA records, there may be multiple addresses from multiple
3397 records. For A6 records (currently not expected to be used) there may be
3398 multiple addresses from a single record. */
3400 for (da = cb->rhs->next; da != NULL; da = da->next)
3401 addlist = string_sprintf("%s, %s", addlist, da->address);
3403 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3406 /* Address list check; this can be either for equality, or via a bitmask.
3407 In the latter case, all the bits must match. */
3411 for (da = cb->rhs; da != NULL; da = da->next)
3415 uschar *ptr = iplist;
3418 /* Handle exact matching */
3422 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3424 if (Ustrcmp(CS da->address, ip) == 0) break;
3428 /* Handle bitmask matching */
3435 /* At present, all known DNS blocking lists use A records, with
3436 IPv4 addresses on the RHS encoding the information they return. I
3437 wonder if this will linger on as the last vestige of IPv4 when IPv6
3438 is ubiquitous? Anyway, for now we use paranoia code to completely
3439 ignore IPv6 addresses. The default mask is 0, which always matches.
3440 We change this only for IPv4 addresses in the list. */
3442 if (host_aton(da->address, address) == 1) mask = address[0];
3444 /* Scan the returned addresses, skipping any that are IPv6 */
3446 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3448 if (host_aton(ip, address) != 1) continue;
3449 if ((address[0] & mask) == address[0]) break;
3455 (a) An IP address in an any ('=') list matched, or
3456 (b) No IP address in an all ('==') list matched
3458 then we're done searching. */
3460 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3463 /* If da == NULL, either
3465 (a) No IP address in an any ('=') list matched, or
3466 (b) An IP address in an all ('==') list didn't match
3468 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3471 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3479 res = US"was no match";
3482 res = US"was an exclude match";
3485 res = US"was an IP address that did not match";
3488 res = US"were no IP addresses that did not match";
3491 debug_printf("=> but we are not accepting this block class because\n");
3492 debug_printf("=> there %s for %s%c%s\n",
3494 ((match_type & MT_ALL) == 0)? "" : "=",
3495 bitmask? '&' : '=', iplist);
3501 /* Either there was no IP list, or the record matched, implying that the
3502 domain is on the list. We now want to find a corresponding TXT record. If an
3503 alternate domain is specified for the TXT record, call this function
3504 recursively to look that up; this has the side effect of re-checking that
3505 there is indeed an A record at the alternate domain. */
3507 if (domain_txt != domain)
3508 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3509 FALSE, match_type, defer_return);
3511 /* If there is no alternate domain, look up a TXT record in the main domain
3512 if it has not previously been cached. */
3516 cb->text_set = TRUE;
3517 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3520 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3522 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3523 if (rr->type == T_TXT) break;
3526 int len = (rr->data)[0];
3527 if (len > 511) len = 127;
3528 store_pool = POOL_PERM;
3529 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3530 store_pool = old_pool;
3535 dnslist_value = addlist;
3536 dnslist_text = cb->text;
3540 /* There was a problem with the DNS lookup */
3542 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3544 log_write(L_dnslist_defer, LOG_MAIN,
3545 "DNS list lookup defer (probably timeout) for %s: %s", query,
3546 (defer_return == OK)? US"assumed in list" :
3547 (defer_return == FAIL)? US"assumed not in list" :
3548 US"returned DEFER");
3549 return defer_return;
3552 /* No entry was found in the DNS; continue for next domain */
3556 debug_printf("DNS lookup for %s failed\n", query);
3557 debug_printf("=> that means %s is not listed at %s\n",
3567 /*************************************************
3568 * Check host against DNS black lists *
3569 *************************************************/
3571 /* This function runs checks against a list of DNS black lists, until one
3572 matches. Each item on the list can be of the form
3574 domain=ip-address/key
3576 The domain is the right-most domain that is used for the query, for example,
3577 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3578 if the DNS lookup returns a matching IP address. Several addresses may be
3579 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3581 If no key is given, what is looked up in the domain is the inverted IP address
3582 of the current client host. If a key is given, it is used to construct the
3583 domain for the lookup. For example:
3585 dsn.rfc-ignorant.org/$sender_address_domain
3587 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3588 then we check for a TXT record for an error message, and if found, save its
3589 value in $dnslist_text. We also cache everything in a tree, to optimize
3592 The TXT record is normally looked up in the same domain as the A record, but
3593 when many lists are combined in a single DNS domain, this will not be a very
3594 specific message. It is possible to specify a different domain for looking up
3595 TXT records; this is given before the main domain, comma-separated. For
3598 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3599 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3601 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3603 Note: an address for testing RBL is 192.203.178.39
3604 Note: an address for testing DUL is 192.203.178.4
3605 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3608 listptr the domain/address/data list
3610 Returns: OK successful lookup (i.e. the address is on the list), or
3611 lookup deferred after +include_unknown
3612 FAIL name not found, or no data found for the given type, or
3613 lookup deferred after +exclude_unknown (default)
3614 DEFER lookup failure, if +defer_unknown was set
3618 verify_check_dnsbl(uschar **listptr)
3621 int defer_return = FAIL;
3622 uschar *list = *listptr;
3625 uschar buffer[1024];
3626 uschar revadd[128]; /* Long enough for IPv6 address */
3628 /* Indicate that the inverted IP address is not yet set up */
3632 /* In case this is the first time the DNS resolver is being used. */
3634 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3636 /* Loop through all the domains supplied, until something matches */
3638 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3641 BOOL bitmask = FALSE;
3648 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3650 /* Deal with special values that change the behaviour on defer */
3652 if (domain[0] == '+')
3654 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3655 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3656 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3658 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3663 /* See if there's explicit data to be looked up */
3665 key = Ustrchr(domain, '/');
3666 if (key != NULL) *key++ = 0;
3668 /* See if there's a list of addresses supplied after the domain name. This is
3669 introduced by an = or a & character; if preceded by = we require all matches
3670 and if preceded by ! we invert the result. */
3672 iplist = Ustrchr(domain, '=');
3676 iplist = Ustrchr(domain, '&');
3679 if (iplist != NULL) /* Found either = or & */
3681 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3683 match_type |= MT_NOT;
3687 *iplist++ = 0; /* Terminate domain, move on */
3689 /* If we found = (bitmask == FALSE), check for == or =& */
3691 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3693 bitmask = *iplist++ == '&';
3694 match_type |= MT_ALL;
3698 /* If there is a comma in the domain, it indicates that a second domain for
3699 looking up TXT records is provided, before the main domain. Otherwise we must
3700 set domain_txt == domain. */
3702 domain_txt = domain;
3703 comma = Ustrchr(domain, ',');
3710 /* Check that what we have left is a sensible domain name. There is no reason
3711 why these domains should in fact use the same syntax as hosts and email
3712 domains, but in practice they seem to. However, there is little point in
3713 actually causing an error here, because that would no doubt hold up incoming
3714 mail. Instead, I'll just log it. */
3716 for (s = domain; *s != 0; s++)
3718 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3720 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3721 "strange characters - is this right?", domain);
3726 /* Check the alternate domain if present */
3728 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3730 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3732 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3733 "strange characters - is this right?", domain_txt);
3738 /* If there is no key string, construct the query by adding the domain name
3739 onto the inverted host address, and perform a single DNS lookup. */
3743 if (sender_host_address == NULL) return FAIL; /* can never match */
3744 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3745 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3746 iplist, bitmask, match_type, defer_return);
3749 dnslist_domain = string_copy(domain_txt);
3750 dnslist_matched = string_copy(sender_host_address);
3751 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3752 sender_host_address, dnslist_domain);
3754 if (rc != FAIL) return rc; /* OK or DEFER */
3757 /* If there is a key string, it can be a list of domains or IP addresses to
3758 be concatenated with the main domain. */
3765 uschar keybuffer[256];
3766 uschar keyrevadd[128];
3768 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3769 sizeof(keybuffer))) != NULL)
3771 uschar *prepend = keydomain;
3773 if (string_is_ip_address(keydomain, NULL) != 0)
3775 invert_address(keyrevadd, keydomain);
3776 prepend = keyrevadd;
3779 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3780 bitmask, match_type, defer_return);
3784 dnslist_domain = string_copy(domain_txt);
3785 dnslist_matched = string_copy(keydomain);
3786 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3787 keydomain, dnslist_domain);
3791 /* If the lookup deferred, remember this fact. We keep trying the rest
3792 of the list to see if we get a useful result, and if we don't, we return
3793 DEFER at the end. */
3795 if (rc == DEFER) defer = TRUE;
3796 } /* continue with next keystring domain/address */
3798 if (defer) return DEFER;
3800 } /* continue with next dnsdb outer domain */
3807 /* End of verify.c */