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;
472 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
474 !smtp_get_port(tf->port, addr, &port, US"callout"))
475 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
478 /* Set HELO string according to the protocol */
479 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
480 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
483 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
485 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
490 tls_out.dane_verified = FALSE;
491 tls_out.tlsa_usage = 0;
493 dane_required = verify_check_this_host(&ob->hosts_require_dane, NULL,
494 host->name, host->address, NULL) == OK;
496 if (host->dnssec == DS_YES)
499 || verify_check_this_host(&ob->hosts_try_dane, NULL,
500 host->name, host->address, NULL) == OK
502 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK)
505 else if (dane_required)
507 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
512 ob->tls_tempfail_tryclear = FALSE;
516 /* Set up the buffer for reading SMTP response packets. */
518 inblock.buffer = inbuffer;
519 inblock.buffersize = sizeof(inbuffer);
520 inblock.ptr = inbuffer;
521 inblock.ptrend = inbuffer;
523 /* Set up the buffer for holding SMTP commands while pipelining */
525 outblock.buffer = outbuffer;
526 outblock.buffersize = sizeof(outbuffer);
527 outblock.ptr = outbuffer;
528 outblock.cmd_count = 0;
529 outblock.authenticating = FALSE;
531 /* Reset the parameters of a TLS session */
532 tls_out.cipher = tls_out.peerdn = NULL;
534 /* Connect to the host; on failure, just loop for the next one, but we
535 set the error for the last one. Use the callout_connect timeout. */
537 tls_retry_connection:
539 inblock.sock = outblock.sock =
540 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL
541 #ifdef EXPERIMENTAL_TPDA
542 /*XXX tpda action? NULL for now. */
546 /* reconsider DSCP here */
547 if (inblock.sock < 0)
549 addr->message = string_sprintf("could not connect to %s [%s]: %s",
550 host->name, host->address, strerror(errno));
551 deliver_host = deliver_host_address = NULL;
552 deliver_domain = save_deliver_domain;
556 /* Expand the helo_data string to find the host name to use. */
558 if (tf->helo_data != NULL)
560 uschar *s = expand_string(tf->helo_data);
562 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
563 "helo_data value for callout: %s", addr->address,
564 expand_string_message);
565 else active_hostname = s;
568 /* Wait for initial response, and send HELO. The smtp_write_command()
569 function leaves its command in big_buffer. This is used in error responses.
570 Initialize it in case the connection is rejected. */
572 Ustrcpy(big_buffer, "initial connection");
574 /* Unless ssl-on-connect, wait for the initial greeting */
578 if (!smtps || (smtps && tls_out.active >= 0))
581 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
582 goto RESPONSE_FAILED;
584 #ifdef EXPERIMENTAL_TPDA
585 if (tpda_raise_event(addr->transport->tpda_event_action,
586 US"smtp:connect", responsebuffer) == DEFER)
588 /* Logging? Debug? */
589 goto RESPONSE_FAILED;
594 /* Not worth checking greeting line for ESMTP support */
595 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
596 host->name, host->address, NULL) != OK))
598 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
603 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
606 ob->tls_tempfail_tryclear = FALSE;
608 else /* all other cases */
613 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
614 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
616 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
618 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
621 goto RESPONSE_FAILED;
627 goto esmtp_retry; /* fallback to HELO */
630 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
632 if (esmtp && !suppress_tls && tls_out.active < 0)
634 if (regex_STARTTLS == NULL) regex_STARTTLS =
635 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
637 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
638 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
645 /* If TLS is available on this connection attempt to
646 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
647 send another EHLO - the server may give a different answer in secure mode. We
648 use a separate buffer for reading the response to STARTTLS so that if it is
649 negative, the original EHLO data is available for subsequent analysis, should
650 the client not be required to use TLS. If the response is bad, copy the buffer
651 for error analysis. */
655 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
656 host->address, NULL) != OK &&
657 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
658 host->address, NULL) != OK
661 uschar buffer2[4096];
663 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
666 /* If there is an I/O error, transmission of this message is deferred. If
667 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
668 false, we also defer. However, if there is a temporary rejection of STARTTLS
669 and tls_tempfail_tryclear is true, or if there is an outright rejection of
670 STARTTLS, we carry on. This means we will try to send the message in clear,
671 unless the host is in hosts_require_tls (tested below). */
673 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
674 ob->command_timeout))
676 if (errno != 0 || buffer2[0] == 0 ||
677 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
679 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
681 goto RESPONSE_FAILED;
685 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
688 int oldtimeout = ob->command_timeout;
691 ob->command_timeout = callout;
692 rc = tls_client_start(inblock.sock, host, addr, addr->transport
693 #ifdef EXPERIMENTAL_DANE
694 , dane ? &tlsa_dnsa : NULL
697 ob->command_timeout = oldtimeout;
699 /* TLS negotiation failed; give an error. Try in clear on a new connection,
700 if the options permit it for this host. */
704 && ob->tls_tempfail_tryclear
706 && verify_check_this_host(&(ob->hosts_require_tls), NULL,
707 host->name, host->address, NULL) != OK
710 (void)close(inblock.sock);
711 #ifdef EXPERIMENTAL_TPDA
712 (void) tpda_raise_event(addr->transport->tpda_event_action,
713 US"tcp:close", NULL);
715 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
716 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
718 goto tls_retry_connection;
720 /*save_errno = ERRNO_TLSFAILURE;*/
721 /*message = US"failure while setting up TLS session";*/
727 /* TLS session is set up. Copy info for logging. */
728 addr->cipher = tls_out.cipher;
729 addr->peerdn = tls_out.peerdn;
731 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
733 goto smtps_redo_greeting;
735 /* For STARTTLS we need to redo EHLO */
740 /* If the host is required to use a secure channel, ensure that we have one. */
741 if (tls_out.active < 0)
743 #ifdef EXPERIMENTAL_DANE
746 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
747 host->address, NULL) == OK
750 /*save_errno = ERRNO_TLSREQUIRED;*/
751 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
752 host->name, host->address,
753 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
758 #endif /*SUPPORT_TLS*/
760 done = TRUE; /* so far so good; have response to HELO */
762 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
764 /* For now, transport_filter by cutthrough-delivery is not supported */
765 /* Need proper integration with the proper transport mechanism. */
766 if (cutthrough_delivery)
768 if (addr->transport->filter_command)
770 cutthrough_delivery= FALSE;
771 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
776 cutthrough_delivery= FALSE;
777 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
786 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
788 /* Failure to accept HELO is cached; this blocks the whole domain for all
789 senders. I/O errors and defer responses are not cached. */
793 *failure_ptr = US"mail"; /* At or before MAIL */
794 if (errno == 0 && responsebuffer[0] == '5')
796 setflag(addr, af_verify_nsfail);
797 new_domain_record.result = ccache_reject;
801 /* If we haven't authenticated, but are required to, give up. */
804 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
805 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
807 /* Copy AUTH info for logging */
808 ( (addr->authenticator = client_authenticator),
809 (addr->auth_id = client_authenticated_id),
811 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
812 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
815 ( (addr->auth_sndr = client_authenticated_sender),
817 /* Send the MAIL command */
818 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
819 from_address, responsebuffer) >= 0)
822 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
825 deliver_host = deliver_host_address = NULL;
826 deliver_domain = save_deliver_domain;
828 /* If the host does not accept MAIL FROM:<>, arrange to cache this
829 information, but again, don't record anything for an I/O error or a defer. Do
830 not cache rejections of MAIL when a non-empty sender has been used, because
831 that blocks the whole domain for all senders. */
835 *failure_ptr = US"mail"; /* At or before MAIL */
836 if (errno == 0 && responsebuffer[0] == '5')
838 setflag(addr, af_verify_nsfail);
839 if (from_address[0] == 0)
840 new_domain_record.result = ccache_reject_mfnull;
844 /* Otherwise, proceed to check a "random" address (if required), then the
845 given address, and the postmaster address (if required). Between each check,
846 issue RSET, because some servers accept only one recipient after MAIL
849 Before doing this, set the result in the domain cache record to "accept",
850 unless its previous value was ccache_reject_mfnull. In that case, the domain
851 rejects MAIL FROM:<> and we want to continue to remember that. When that is
852 the case, we have got here only in the case of a recipient verification with
853 a non-null sender. */
857 new_domain_record.result =
858 (old_domain_cache_result == ccache_reject_mfnull)?
859 ccache_reject_mfnull: ccache_accept;
861 /* Do the random local part check first */
863 if (random_local_part != NULL)
865 uschar randombuffer[1024];
867 smtp_write_command(&outblock, FALSE,
868 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
869 addr->domain) >= 0 &&
870 smtp_read_response(&inblock, randombuffer,
871 sizeof(randombuffer), '2', callout);
873 /* Remember when we last did a random test */
875 new_domain_record.random_stamp = time(NULL);
877 /* If accepted, we aren't going to do any further tests below. */
881 new_domain_record.random_result = ccache_accept;
884 /* Otherwise, cache a real negative response, and get back to the right
885 state to send RCPT. Unless there's some problem such as a dropped
886 connection, we expect to succeed, because the commands succeeded above. */
890 if (randombuffer[0] == '5')
891 new_domain_record.random_result = ccache_reject;
894 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
895 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
898 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
899 from_address) >= 0 &&
900 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
903 else done = FALSE; /* Some timeout/connection problem */
906 /* If the host is accepting all local parts, as determined by the "random"
907 check, we don't need to waste time doing any further checking. */
909 if (new_domain_record.random_result != ccache_accept && done)
911 /* Get the rcpt_include_affixes flag from the transport if there is one,
912 but assume FALSE if there is not. */
915 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
916 transport_rcpt_address(addr,
917 (addr->transport == NULL)? FALSE :
918 addr->transport->rcpt_include_affixes)) >= 0 &&
919 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
923 new_address_record.result = ccache_accept;
924 else if (errno == 0 && responsebuffer[0] == '5')
926 *failure_ptr = US"recipient";
927 new_address_record.result = ccache_reject;
930 /* Do postmaster check if requested; if a full check is required, we
931 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
933 if (done && pm_mailfrom != NULL)
935 /*XXX not suitable for cutthrough - sequencing problems */
936 cutthrough_delivery= FALSE;
937 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
940 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
941 smtp_read_response(&inblock, responsebuffer,
942 sizeof(responsebuffer), '2', callout) &&
944 smtp_write_command(&outblock, FALSE,
945 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
946 smtp_read_response(&inblock, responsebuffer,
947 sizeof(responsebuffer), '2', callout) &&
949 /* First try using the current domain */
952 smtp_write_command(&outblock, FALSE,
953 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
954 smtp_read_response(&inblock, responsebuffer,
955 sizeof(responsebuffer), '2', callout)
960 /* If that doesn't work, and a full check is requested,
961 try without the domain. */
964 (options & vopt_callout_fullpm) != 0 &&
965 smtp_write_command(&outblock, FALSE,
966 "RCPT TO:<postmaster>\r\n") >= 0 &&
967 smtp_read_response(&inblock, responsebuffer,
968 sizeof(responsebuffer), '2', callout)
971 /* Sort out the cache record */
973 new_domain_record.postmaster_stamp = time(NULL);
976 new_domain_record.postmaster_result = ccache_accept;
977 else if (errno == 0 && responsebuffer[0] == '5')
979 *failure_ptr = US"postmaster";
980 setflag(addr, af_verify_pmfail);
981 new_domain_record.postmaster_result = ccache_reject;
984 } /* Random not accepted */
985 } /* MAIL FROM: accepted */
987 /* For any failure of the main check, other than a negative response, we just
988 close the connection and carry on. We can identify a negative response by the
989 fact that errno is zero. For I/O errors it will be non-zero
991 Set up different error texts for logging and for sending back to the caller
992 as an SMTP response. Log in all cases, using a one-line format. For sender
993 callouts, give a full response to the caller, but for recipient callouts,
994 don't give the IP address because this may be an internal host whose identity
995 is not to be widely broadcast. */
999 if (errno == ETIMEDOUT)
1001 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
1004 else if (errno == 0)
1006 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1009 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1010 big_buffer, host->name, host->address,
1011 string_printing(responsebuffer));
1013 addr->user_message = is_recipient?
1014 string_sprintf("Callout verification failed:\n%s", responsebuffer)
1016 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1017 host->address, big_buffer, responsebuffer);
1019 /* Hard rejection ends the process */
1021 if (responsebuffer[0] == '5') /* Address rejected */
1029 /* End the SMTP conversation and close the connection. */
1031 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
1032 and we have no cutthrough conn so far
1033 here is where we want to leave the conn open */
1034 if ( cutthrough_delivery
1037 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
1038 && !random_local_part
1040 && cutthrough_fd < 0
1043 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
1044 cutthrough_addr = *addr; /* Save the address_item for later logging */
1045 cutthrough_addr.next = NULL;
1046 cutthrough_addr.host_used = store_get(sizeof(host_item));
1047 *(cutthrough_addr.host_used) = *host;
1049 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
1050 ctblock.buffer = ctbuffer;
1051 ctblock.buffersize = sizeof(ctbuffer);
1052 ctblock.ptr = ctbuffer;
1053 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1054 ctblock.sock = cutthrough_fd;
1058 /* Ensure no cutthrough on multiple address verifies */
1059 if (options & vopt_callout_recipsender)
1060 cancel_cutthrough_connection("multiple verify calls");
1061 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1064 tls_close(FALSE, TRUE);
1066 (void)close(inblock.sock);
1067 #ifdef EXPERIMENTAL_TPDA
1068 (void) tpda_raise_event(addr->transport->tpda_event_action,
1069 US"tcp:close", NULL);
1073 } /* Loop through all hosts, while !done */
1076 /* If we get here with done == TRUE, a successful callout happened, and yield
1077 will be set OK or FAIL according to the response to the RCPT command.
1078 Otherwise, we looped through the hosts but couldn't complete the business.
1079 However, there may be domain-specific information to cache in both cases.
1081 The value of the result field in the new_domain record is ccache_unknown if
1082 there was an error before or with MAIL FROM:, and errno was not zero,
1083 implying some kind of I/O error. We don't want to write the cache in that case.
1084 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1086 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1088 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1091 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1095 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1096 (int)sizeof(dbdata_callout_cache));
1097 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1098 " result=%d postmaster=%d random=%d\n",
1099 new_domain_record.result,
1100 new_domain_record.postmaster_result,
1101 new_domain_record.random_result);
1105 /* If a definite result was obtained for the callout, cache it unless caching
1110 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1112 if (dbm_file == NULL)
1113 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1114 if (dbm_file == NULL)
1116 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1120 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1121 (int)sizeof(dbdata_callout_cache_address));
1122 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1123 (new_address_record.result == ccache_accept)? "positive" : "negative");
1128 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1129 temporary error. If there was only one host, and a response was received, leave
1130 it alone if supplying details. Otherwise, give a generic response. */
1134 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1135 is_recipient? "recipient" : "sender");
1138 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1140 addr->user_message = (!smtp_return_error_details)? dullmsg :
1141 string_sprintf("%s for <%s>.\n"
1142 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1143 "they may be permanently unreachable from this server. In the latter case,\n%s",
1144 dullmsg, addr->address,
1146 "the address will never be accepted."
1148 "you need to change the address or create an MX record for its domain\n"
1149 "if it is supposed to be generally accessible from the Internet.\n"
1150 "Talk to your mail administrator for details.");
1152 /* Force a specific error code */
1154 addr->basic_errno = ERRNO_CALLOUTDEFER;
1157 /* Come here from within the cache-reading code on fast-track exit. */
1160 if (dbm_file != NULL) dbfn_close(dbm_file);
1166 /* Called after recipient-acl to get a cutthrough connection open when
1167 one was requested and a recipient-verify wasn't subsequently done.
1170 open_cutthrough_connection( address_item * addr )
1174 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1175 /* We must use a copy of the address for verification, because it might
1179 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1180 (void) verify_address(&addr2, NULL,
1181 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1182 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1184 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1190 /* Send given number of bytes from the buffer */
1192 cutthrough_send(int n)
1194 if(cutthrough_fd < 0)
1199 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1201 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1204 transport_count += n;
1205 ctblock.ptr= ctblock.buffer;
1209 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1216 _cutthrough_puts(uschar * cp, int n)
1220 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1221 if(!cutthrough_send(ctblock.buffersize))
1224 *ctblock.ptr++ = *cp++;
1229 /* Buffered output of counted data block. Return boolean success */
1231 cutthrough_puts(uschar * cp, int n)
1233 if (cutthrough_fd < 0) return TRUE;
1234 if (_cutthrough_puts(cp, n)) return TRUE;
1235 cancel_cutthrough_connection("transmit failed");
1241 _cutthrough_flush_send( void )
1243 int n= ctblock.ptr-ctblock.buffer;
1246 if(!cutthrough_send(n))
1252 /* Send out any bufferred output. Return boolean success. */
1254 cutthrough_flush_send( void )
1256 if (_cutthrough_flush_send()) return TRUE;
1257 cancel_cutthrough_connection("transmit failed");
1263 cutthrough_put_nl( void )
1265 return cutthrough_puts(US"\r\n", 2);
1269 /* Get and check response from cutthrough target */
1271 cutthrough_response(char expect, uschar ** copy)
1273 smtp_inblock inblock;
1274 uschar inbuffer[4096];
1275 uschar responsebuffer[4096];
1277 inblock.buffer = inbuffer;
1278 inblock.buffersize = sizeof(inbuffer);
1279 inblock.ptr = inbuffer;
1280 inblock.ptrend = inbuffer;
1281 inblock.sock = cutthrough_fd;
1282 /* this relies on (inblock.sock == tls_out.active) */
1283 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1284 cancel_cutthrough_connection("target timeout on read");
1289 *copy= cp= string_copy(responsebuffer);
1290 /* Trim the trailing end of line */
1291 cp += Ustrlen(responsebuffer);
1292 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1293 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1296 return responsebuffer[0];
1300 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1302 cutthrough_predata( void )
1304 if(cutthrough_fd < 0)
1307 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1308 cutthrough_puts(US"DATA\r\n", 6);
1309 cutthrough_flush_send();
1311 /* Assume nothing buffered. If it was it gets ignored. */
1312 return cutthrough_response('3', NULL) == '3';
1316 /* fd and use_crlf args only to match write_chunk() */
1318 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1321 while(s && (s2 = Ustrchr(s, '\n')))
1323 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1331 /* Buffered send of headers. Return success boolean. */
1332 /* Expands newlines to wire format (CR,NL). */
1333 /* Also sends header-terminating blank line. */
1335 cutthrough_headers_send( void )
1337 if(cutthrough_fd < 0)
1340 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1341 but having a separate buffered-output function (for now)
1343 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1345 if (!transport_headers_send(&cutthrough_addr, cutthrough_fd,
1346 cutthrough_addr.transport->add_headers, cutthrough_addr.transport->remove_headers,
1347 &cutthrough_write_chunk, TRUE,
1348 cutthrough_addr.transport->rewrite_rules, cutthrough_addr.transport->rewrite_existflags))
1351 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1357 close_cutthrough_connection( const char * why )
1359 if(cutthrough_fd >= 0)
1361 /* We could be sending this after a bunch of data, but that is ok as
1362 the only way to cancel the transfer in dataphase is to drop the tcp
1363 conn before the final dot.
1365 ctblock.ptr = ctbuffer;
1366 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1367 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1368 _cutthrough_flush_send();
1369 /* No wait for response */
1372 tls_close(FALSE, TRUE);
1374 (void)close(cutthrough_fd);
1376 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1378 ctblock.ptr = ctbuffer;
1382 cancel_cutthrough_connection( const char * why )
1384 close_cutthrough_connection(why);
1385 cutthrough_delivery= FALSE;
1391 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1392 Log an OK response as a transmission.
1393 Close the connection.
1394 Return smtp response-class digit.
1397 cutthrough_finaldot( void )
1399 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1401 /* Assume data finshed with new-line */
1402 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1403 return cutthrough_addr.message;
1405 switch(cutthrough_response('2', &cutthrough_addr.message))
1408 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1409 close_cutthrough_connection("delivered");
1413 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1417 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1423 return cutthrough_addr.message;
1428 /*************************************************
1429 * Copy error to toplevel address *
1430 *************************************************/
1432 /* This function is used when a verify fails or defers, to ensure that the
1433 failure or defer information is in the original toplevel address. This applies
1434 when an address is redirected to a single new address, and the failure or
1435 deferral happens to the child address.
1438 vaddr the verify address item
1439 addr the final address item
1442 Returns: the value of YIELD
1446 copy_error(address_item *vaddr, address_item *addr, int yield)
1450 vaddr->message = addr->message;
1451 vaddr->user_message = addr->user_message;
1452 vaddr->basic_errno = addr->basic_errno;
1453 vaddr->more_errno = addr->more_errno;
1454 vaddr->p.address_data = addr->p.address_data;
1455 copyflag(vaddr, addr, af_pass_message);
1463 /**************************************************
1464 * printf that automatically handles TLS if needed *
1465 ***************************************************/
1467 /* This function is used by verify_address() as a substitute for all fprintf()
1468 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1469 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1470 that assumes that we always use the smtp_out FILE* when not using TLS or the
1471 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1472 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1476 f the candidate FILE* to write to
1477 format format string
1478 ... optional arguments
1484 static void PRINTF_FUNCTION(2,3)
1485 respond_printf(FILE *f, const char *format, ...)
1489 va_start(ap, format);
1490 if (smtp_out && (f == smtp_out))
1491 smtp_vprintf(format, ap);
1493 vfprintf(f, format, ap);
1499 /*************************************************
1500 * Verify an email address *
1501 *************************************************/
1503 /* This function is used both for verification (-bv and at other times) and
1504 address testing (-bt), which is indicated by address_test_mode being set.
1507 vaddr contains the address to verify; the next field in this block
1509 f if not NULL, write the result to this file
1510 options various option bits:
1511 vopt_fake_sender => this sender verify is not for the real
1512 sender (it was verify=sender=xxxx or an address from a
1513 header line) - rewriting must not change sender_address
1514 vopt_is_recipient => this is a recipient address, otherwise
1515 it's a sender address - this affects qualification and
1516 rewriting and messages from callouts
1517 vopt_qualify => qualify an unqualified address; else error
1518 vopt_expn => called from SMTP EXPN command
1519 vopt_success_on_redirect => when a new address is generated
1520 the verification instantly succeeds
1522 These ones are used by do_callout() -- the options variable
1525 vopt_callout_fullpm => if postmaster check, do full one
1526 vopt_callout_no_cache => don't use callout cache
1527 vopt_callout_random => do the "random" thing
1528 vopt_callout_recipsender => use real sender for recipient
1529 vopt_callout_recippmaster => use postmaster for recipient
1531 callout if > 0, specifies that callout is required, and gives timeout
1532 for individual commands
1533 callout_overall if > 0, gives overall timeout for the callout function;
1534 if < 0, a default is used (see do_callout())
1535 callout_connect the connection timeout for callouts
1536 se_mailfrom when callout is requested to verify a sender, use this
1537 in MAIL FROM; NULL => ""
1538 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1539 thing and use this as the sender address (may be "")
1541 routed if not NULL, set TRUE if routing succeeded, so we can
1542 distinguish between routing failed and callout failed
1544 Returns: OK address verified
1545 FAIL address failed to verify
1546 DEFER can't tell at present
1550 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1551 int callout_overall, int callout_connect, uschar *se_mailfrom,
1552 uschar *pm_mailfrom, BOOL *routed)
1555 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1556 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1557 BOOL expn = (options & vopt_expn) != 0;
1558 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1561 int verify_type = expn? v_expn :
1562 address_test_mode? v_none :
1563 is_recipient? v_recipient : v_sender;
1564 address_item *addr_list;
1565 address_item *addr_new = NULL;
1566 address_item *addr_remote = NULL;
1567 address_item *addr_local = NULL;
1568 address_item *addr_succeed = NULL;
1569 uschar **failure_ptr = is_recipient?
1570 &recipient_verify_failure : &sender_verify_failure;
1571 uschar *ko_prefix, *cr;
1572 uschar *address = vaddr->address;
1573 uschar *save_sender;
1574 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1576 /* Clear, just in case */
1578 *failure_ptr = NULL;
1580 /* Set up a prefix and suffix for error message which allow us to use the same
1581 output statements both in EXPN mode (where an SMTP response is needed) and when
1582 debugging with an output file. */
1586 ko_prefix = US"553 ";
1589 else ko_prefix = cr = US"";
1591 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1593 if (parse_find_at(address) == NULL)
1595 if ((options & vopt_qualify) == 0)
1598 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1599 ko_prefix, address, cr);
1600 *failure_ptr = US"qualify";
1603 address = rewrite_address_qualify(address, is_recipient);
1608 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1609 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1612 /* Rewrite and report on it. Clear the domain and local part caches - these
1613 may have been set by domains and local part tests during an ACL. */
1615 if (global_rewrite_rules != NULL)
1617 uschar *old = address;
1618 address = rewrite_address(address, is_recipient, FALSE,
1619 global_rewrite_rules, rewrite_existflags);
1622 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1623 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1624 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1628 /* If this is the real sender address, we must update sender_address at
1629 this point, because it may be referred to in the routers. */
1631 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1632 sender_address = address;
1634 /* If the address was rewritten to <> no verification can be done, and we have
1635 to return OK. This rewriting is permitted only for sender addresses; for other
1636 addresses, such rewriting fails. */
1638 if (address[0] == 0) return OK;
1640 /* Flip the legacy TLS-related variables over to the outbound set in case
1641 they're used in the context of a transport used by verification. Reset them
1642 at exit from this routine. */
1644 tls_modify_variables(&tls_out);
1646 /* Save a copy of the sender address for re-instating if we change it to <>
1647 while verifying a sender address (a nice bit of self-reference there). */
1649 save_sender = sender_address;
1651 /* Update the address structure with the possibly qualified and rewritten
1652 address. Set it up as the starting address on the chain of new addresses. */
1654 vaddr->address = address;
1657 /* We need a loop, because an address can generate new addresses. We must also
1658 cope with generated pipes and files at the top level. (See also the code and
1659 comment in deliver.c.) However, it is usually the case that the router for
1660 user's .forward files has its verify flag turned off.
1662 If an address generates more than one child, the loop is used only when
1663 full_info is set, and this can only be set locally. Remote enquiries just get
1664 information about the top level address, not anything that it generated. */
1666 while (addr_new != NULL)
1669 address_item *addr = addr_new;
1671 addr_new = addr->next;
1676 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1677 debug_printf("Considering %s\n", addr->address);
1680 /* Handle generated pipe, file or reply addresses. We don't get these
1681 when handling EXPN, as it does only one level of expansion. */
1683 if (testflag(addr, af_pfr))
1690 if (addr->address[0] == '>')
1692 allow = testflag(addr, af_allow_reply);
1693 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1697 allow = (addr->address[0] == '|')?
1698 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1699 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1702 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1703 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1704 "%s\n", addr->message);
1706 fprintf(f, "\n transport = %s\n", addr->transport->name);
1708 fprintf(f, " *** forbidden ***\n");
1713 /* Just in case some router parameter refers to it. */
1715 return_path = (addr->p.errors_address != NULL)?
1716 addr->p.errors_address : sender_address;
1718 /* Split the address into domain and local part, handling the %-hack if
1719 necessary, and then route it. While routing a sender address, set
1720 $sender_address to <> because that is what it will be if we were trying to
1721 send a bounce to the sender. */
1723 if (routed != NULL) *routed = FALSE;
1724 if ((rc = deliver_split_address(addr)) == OK)
1726 if (!is_recipient) sender_address = null_sender;
1727 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1728 &addr_succeed, verify_type);
1729 sender_address = save_sender; /* Put back the real sender */
1732 /* If routing an address succeeded, set the flag that remembers, for use when
1733 an ACL cached a sender verify (in case a callout fails). Then if routing set
1734 up a list of hosts or the transport has a host list, and the callout option
1735 is set, and we aren't in a host checking run, do the callout verification,
1736 and set another flag that notes that a callout happened. */
1740 if (routed != NULL) *routed = TRUE;
1743 host_item *host_list = addr->host_list;
1745 /* Make up some data for use in the case where there is no remote
1748 transport_feedback tf = {
1749 NULL, /* interface (=> any) */
1750 US"smtp", /* port */
1751 US"smtp", /* protocol */
1753 US"$smtp_active_hostname", /* helo_data */
1754 FALSE, /* hosts_override */
1755 FALSE, /* hosts_randomize */
1756 FALSE, /* gethostbyname */
1757 TRUE, /* qualify_single */
1758 FALSE /* search_parents */
1761 /* If verification yielded a remote transport, we want to use that
1762 transport's options, so as to mimic what would happen if we were really
1763 sending a message to this address. */
1765 if (addr->transport != NULL && !addr->transport->info->local)
1767 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1769 /* If the transport has hosts and the router does not, or if the
1770 transport is configured to override the router's hosts, we must build a
1771 host list of the transport's hosts, and find the IP addresses */
1773 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1776 uschar *save_deliver_domain = deliver_domain;
1777 uschar *save_deliver_localpart = deliver_localpart;
1779 host_list = NULL; /* Ignore the router's hosts */
1781 deliver_domain = addr->domain;
1782 deliver_localpart = addr->local_part;
1783 s = expand_string(tf.hosts);
1784 deliver_domain = save_deliver_domain;
1785 deliver_localpart = save_deliver_localpart;
1789 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1790 "\"%s\" in %s transport for callout: %s", tf.hosts,
1791 addr->transport->name, expand_string_message);
1796 uschar *canonical_name;
1797 host_item *host, *nexthost;
1798 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1800 /* Just ignore failures to find a host address. If we don't manage
1801 to find any addresses, the callout will defer. Note that more than
1802 one address may be found for a single host, which will result in
1803 additional host items being inserted into the chain. Hence we must
1804 save the next host first. */
1806 flags = HOST_FIND_BY_A;
1807 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1808 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1810 for (host = host_list; host != NULL; host = nexthost)
1812 nexthost = host->next;
1813 if (tf.gethostbyname ||
1814 string_is_ip_address(host->name, NULL) != 0)
1815 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1818 uschar * d_request = NULL, * d_require = NULL;
1819 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
1821 smtp_transport_options_block * ob =
1822 (smtp_transport_options_block *)
1823 addr->transport->options_block;
1824 d_request = ob->dnssec_request_domains;
1825 d_require = ob->dnssec_require_domains;
1828 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1829 d_request, d_require, &canonical_name, NULL);
1836 /* Can only do a callout if we have at least one host! If the callout
1837 fails, it will have set ${sender,recipient}_verify_failure. */
1839 if (host_list != NULL)
1841 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1842 if (host_checking && !host_checking_callout)
1845 debug_printf("... callout omitted by default when host testing\n"
1846 "(Use -bhc if you want the callouts to happen.)\n");
1851 deliver_set_expansions(addr);
1853 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1854 callout_connect, options, se_mailfrom, pm_mailfrom);
1859 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1860 "transport provided a host list\n");
1865 /* Otherwise, any failure is a routing failure */
1867 else *failure_ptr = US"route";
1869 /* A router may return REROUTED if it has set up a child address as a result
1870 of a change of domain name (typically from widening). In this case we always
1871 want to continue to verify the new child. */
1873 if (rc == REROUTED) continue;
1875 /* Handle hard failures */
1882 address_item *p = addr->parent;
1884 respond_printf(f, "%s%s %s", ko_prefix,
1885 full_info? addr->address : address,
1886 address_test_mode? "is undeliverable" : "failed to verify");
1887 if (!expn && admin_user)
1889 if (addr->basic_errno > 0)
1890 respond_printf(f, ": %s", strerror(addr->basic_errno));
1891 if (addr->message != NULL)
1892 respond_printf(f, ": %s", addr->message);
1895 /* Show parents iff doing full info */
1897 if (full_info) while (p != NULL)
1899 respond_printf(f, "%s\n <-- %s", cr, p->address);
1902 respond_printf(f, "%s\n", cr);
1904 cancel_cutthrough_connection("routing hard fail");
1908 yield = copy_error(vaddr, addr, FAIL);
1916 else if (rc == DEFER)
1921 address_item *p = addr->parent;
1922 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1923 full_info? addr->address : address);
1924 if (!expn && admin_user)
1926 if (addr->basic_errno > 0)
1927 respond_printf(f, ": %s", strerror(addr->basic_errno));
1928 if (addr->message != NULL)
1929 respond_printf(f, ": %s", addr->message);
1930 else if (addr->basic_errno <= 0)
1931 respond_printf(f, ": unknown error");
1934 /* Show parents iff doing full info */
1936 if (full_info) while (p != NULL)
1938 respond_printf(f, "%s\n <-- %s", cr, p->address);
1941 respond_printf(f, "%s\n", cr);
1943 cancel_cutthrough_connection("routing soft fail");
1947 yield = copy_error(vaddr, addr, DEFER);
1950 else if (yield == OK) yield = DEFER;
1953 /* If we are handling EXPN, we do not want to continue to route beyond
1954 the top level (whose address is in "address"). */
1958 uschar *ok_prefix = US"250-";
1959 if (addr_new == NULL)
1961 if (addr_local == NULL && addr_remote == NULL)
1962 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1964 respond_printf(f, "250 <%s>\r\n", address);
1966 else while (addr_new != NULL)
1968 address_item *addr2 = addr_new;
1969 addr_new = addr2->next;
1970 if (addr_new == NULL) ok_prefix = US"250 ";
1971 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1977 /* Successful routing other than EXPN. */
1981 /* Handle successful routing when short info wanted. Otherwise continue for
1982 other (generated) addresses. Short info is the operational case. Full info
1983 can be requested only when debug_selector != 0 and a file is supplied.
1985 There is a conflict between the use of aliasing as an alternate email
1986 address, and as a sort of mailing list. If an alias turns the incoming
1987 address into just one address (e.g. J.Caesar->jc44) you may well want to
1988 carry on verifying the generated address to ensure it is valid when
1989 checking incoming mail. If aliasing generates multiple addresses, you
1990 probably don't want to do this. Exim therefore treats the generation of
1991 just a single new address as a special case, and continues on to verify the
1992 generated address. */
1994 if (!full_info && /* Stop if short info wanted AND */
1995 (((addr_new == NULL || /* No new address OR */
1996 addr_new->next != NULL || /* More than one new address OR */
1997 testflag(addr_new, af_pfr))) /* New address is pfr */
1999 (addr_new != NULL && /* At least one new address AND */
2000 success_on_redirect))) /* success_on_redirect is set */
2002 if (f != NULL) fprintf(f, "%s %s\n", address,
2003 address_test_mode? "is deliverable" : "verified");
2005 /* If we have carried on to verify a child address, we want the value
2006 of $address_data to be that of the child */
2008 vaddr->p.address_data = addr->p.address_data;
2013 } /* Loop for generated addresses */
2015 /* Display the full results of the successful routing, including any generated
2016 addresses. Control gets here only when full_info is set, which requires f not
2017 to be NULL, and this occurs only when a top-level verify is called with the
2018 debugging switch on.
2020 If there are no local and no remote addresses, and there were no pipes, files,
2021 or autoreplies, and there were no errors or deferments, the message is to be
2022 discarded, usually because of the use of :blackhole: in an alias file. */
2024 if (allok && addr_local == NULL && addr_remote == NULL)
2026 fprintf(f, "mail to %s is discarded\n", address);
2030 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2032 while (addr_list != NULL)
2034 address_item *addr = addr_list;
2035 address_item *p = addr->parent;
2036 addr_list = addr->next;
2038 fprintf(f, "%s", CS addr->address);
2039 #ifdef EXPERIMENTAL_SRS
2040 if(addr->p.srs_sender)
2041 fprintf(f, " [srs = %s]", addr->p.srs_sender);
2044 /* If the address is a duplicate, show something about it. */
2046 if (!testflag(addr, af_pfr))
2049 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2050 fprintf(f, " [duplicate, would not be delivered]");
2051 else tree_add_duplicate(addr->unique, addr);
2054 /* Now show its parents */
2058 fprintf(f, "\n <-- %s", p->address);
2063 /* Show router, and transport */
2065 fprintf(f, "router = %s, ", addr->router->name);
2066 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2067 addr->transport->name);
2069 /* Show any hosts that are set up by a router unless the transport
2070 is going to override them; fiddle a bit to get a nice format. */
2072 if (addr->host_list != NULL && addr->transport != NULL &&
2073 !addr->transport->overrides_hosts)
2078 for (h = addr->host_list; h != NULL; h = h->next)
2080 int len = Ustrlen(h->name);
2081 if (len > maxlen) maxlen = len;
2082 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2083 if (len > maxaddlen) maxaddlen = len;
2085 for (h = addr->host_list; h != NULL; h = h->next)
2087 int len = Ustrlen(h->name);
2088 fprintf(f, " host %s ", h->name);
2089 while (len++ < maxlen) fprintf(f, " ");
2090 if (h->address != NULL)
2092 fprintf(f, "[%s] ", h->address);
2093 len = Ustrlen(h->address);
2095 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2097 fprintf(f, "[unknown] ");
2101 while (len++ < maxaddlen) fprintf(f," ");
2102 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2103 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2104 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2111 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2112 the -bv or -bt case). */
2115 tls_modify_variables(&tls_in);
2123 /*************************************************
2124 * Check headers for syntax errors *
2125 *************************************************/
2127 /* This function checks those header lines that contain addresses, and verifies
2128 that all the addresses therein are syntactially correct.
2131 msgptr where to put an error message
2138 verify_check_headers(uschar **msgptr)
2144 for (h = header_list; h != NULL && yield == OK; h = h->next)
2146 if (h->type != htype_from &&
2147 h->type != htype_reply_to &&
2148 h->type != htype_sender &&
2149 h->type != htype_to &&
2150 h->type != htype_cc &&
2151 h->type != htype_bcc)
2154 colon = Ustrchr(h->text, ':');
2156 while (isspace(*s)) s++;
2158 /* Loop for multiple addresses in the header, enabling group syntax. Note
2159 that we have to reset this after the header has been scanned. */
2161 parse_allow_group = TRUE;
2165 uschar *ss = parse_find_address_end(s, FALSE);
2166 uschar *recipient, *errmess;
2167 int terminator = *ss;
2168 int start, end, domain;
2170 /* Temporarily terminate the string at this point, and extract the
2171 operative address within, allowing group syntax. */
2174 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2177 /* Permit an unqualified address only if the message is local, or if the
2178 sending host is configured to be permitted to send them. */
2180 if (recipient != NULL && domain == 0)
2182 if (h->type == htype_from || h->type == htype_sender)
2184 if (!allow_unqualified_sender) recipient = NULL;
2188 if (!allow_unqualified_recipient) recipient = NULL;
2190 if (recipient == NULL) errmess = US"unqualified address not permitted";
2193 /* It's an error if no address could be extracted, except for the special
2194 case of an empty address. */
2196 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2198 uschar *verb = US"is";
2203 /* Arrange not to include any white space at the end in the
2204 error message or the header name. */
2206 while (t > s && isspace(t[-1])) t--;
2207 while (tt > h->text && isspace(tt[-1])) tt--;
2209 /* Add the address that failed to the error message, since in a
2210 header with very many addresses it is sometimes hard to spot
2211 which one is at fault. However, limit the amount of address to
2212 quote - cases have been seen where, for example, a missing double
2213 quote in a humungous To: header creates an "address" that is longer
2214 than string_sprintf can handle. */
2223 *msgptr = string_printing(
2224 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2225 errmess, tt - h->text, h->text, verb, len, s));
2228 break; /* Out of address loop */
2231 /* Advance to the next address */
2233 s = ss + (terminator? 1:0);
2234 while (isspace(*s)) s++;
2235 } /* Next address */
2237 parse_allow_group = FALSE;
2238 parse_found_group = FALSE;
2239 } /* Next header unless yield has been set FALSE */
2245 /*************************************************
2246 * Check header names for 8-bit characters *
2247 *************************************************/
2249 /* This function checks for invalid charcters in header names. See
2250 RFC 5322, 2.2. and RFC 6532, 3.
2253 msgptr where to put an error message
2260 verify_check_header_names_ascii(uschar **msgptr)
2265 for (h = header_list; h != NULL; h = h->next)
2267 colon = Ustrchr(h->text, ':');
2268 for(s = h->text; s < colon; s++)
2270 if ((*s < 33) || (*s > 126))
2272 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2273 colon - h->text, h->text);
2281 /*************************************************
2282 * Check for blind recipients *
2283 *************************************************/
2285 /* This function checks that every (envelope) recipient is mentioned in either
2286 the To: or Cc: header lines, thus detecting blind carbon copies.
2288 There are two ways of scanning that could be used: either scan the header lines
2289 and tick off the recipients, or scan the recipients and check the header lines.
2290 The original proposed patch did the former, but I have chosen to do the latter,
2291 because (a) it requires no memory and (b) will use fewer resources when there
2292 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2295 Returns: OK if there are no blind recipients
2296 FAIL if there is at least one blind recipient
2300 verify_check_notblind(void)
2303 for (i = 0; i < recipients_count; i++)
2307 uschar *address = recipients_list[i].address;
2309 for (h = header_list; !found && h != NULL; h = h->next)
2313 if (h->type != htype_to && h->type != htype_cc) continue;
2315 colon = Ustrchr(h->text, ':');
2317 while (isspace(*s)) s++;
2319 /* Loop for multiple addresses in the header, enabling group syntax. Note
2320 that we have to reset this after the header has been scanned. */
2322 parse_allow_group = TRUE;
2326 uschar *ss = parse_find_address_end(s, FALSE);
2327 uschar *recipient,*errmess;
2328 int terminator = *ss;
2329 int start, end, domain;
2331 /* Temporarily terminate the string at this point, and extract the
2332 operative address within, allowing group syntax. */
2335 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2338 /* If we found a valid recipient that has a domain, compare it with the
2339 envelope recipient. Local parts are compared case-sensitively, domains
2340 case-insensitively. By comparing from the start with length "domain", we
2341 include the "@" at the end, which ensures that we are comparing the whole
2342 local part of each address. */
2344 if (recipient != NULL && domain != 0)
2346 found = Ustrncmp(recipient, address, domain) == 0 &&
2347 strcmpic(recipient + domain, address + domain) == 0;
2351 /* Advance to the next address */
2353 s = ss + (terminator? 1:0);
2354 while (isspace(*s)) s++;
2355 } /* Next address */
2357 parse_allow_group = FALSE;
2358 parse_found_group = FALSE;
2359 } /* Next header (if found is false) */
2361 if (!found) return FAIL;
2362 } /* Next recipient */
2369 /*************************************************
2370 * Find if verified sender *
2371 *************************************************/
2373 /* Usually, just a single address is verified as the sender of the message.
2374 However, Exim can be made to verify other addresses as well (often related in
2375 some way), and this is useful in some environments. There may therefore be a
2376 chain of such addresses that have previously been tested. This function finds
2377 whether a given address is on the chain.
2379 Arguments: the address to be verified
2380 Returns: pointer to an address item, or NULL
2384 verify_checked_sender(uschar *sender)
2387 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2388 if (Ustrcmp(sender, addr->address) == 0) break;
2396 /*************************************************
2397 * Get valid header address *
2398 *************************************************/
2400 /* Scan the originator headers of the message, looking for an address that
2401 verifies successfully. RFC 822 says:
2403 o The "Sender" field mailbox should be sent notices of
2404 any problems in transport or delivery of the original
2405 messages. If there is no "Sender" field, then the
2406 "From" field mailbox should be used.
2408 o If the "Reply-To" field exists, then the reply should
2409 go to the addresses indicated in that field and not to
2410 the address(es) indicated in the "From" field.
2412 So we check a Sender field if there is one, else a Reply_to field, else a From
2413 field. As some strange messages may have more than one of these fields,
2414 especially if they are resent- fields, check all of them if there is more than
2418 user_msgptr points to where to put a user error message
2419 log_msgptr points to where to put a log error message
2420 callout timeout for callout check (passed to verify_address())
2421 callout_overall overall callout timeout (ditto)
2422 callout_connect connect callout timeout (ditto)
2423 se_mailfrom mailfrom for verify; NULL => ""
2424 pm_mailfrom sender for pm callout check (passed to verify_address())
2425 options callout options (passed to verify_address())
2426 verrno where to put the address basic_errno
2428 If log_msgptr is set to something without setting user_msgptr, the caller
2429 normally uses log_msgptr for both things.
2431 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2432 FAIL is given if no appropriate headers are found
2436 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2437 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2438 uschar *pm_mailfrom, int options, int *verrno)
2440 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2445 for (i = 0; i < 3 && !done; i++)
2448 for (h = header_list; h != NULL && !done; h = h->next)
2450 int terminator, new_ok;
2451 uschar *s, *ss, *endname;
2453 if (h->type != header_types[i]) continue;
2454 s = endname = Ustrchr(h->text, ':') + 1;
2456 /* Scan the addresses in the header, enabling group syntax. Note that we
2457 have to reset this after the header has been scanned. */
2459 parse_allow_group = TRUE;
2463 address_item *vaddr;
2465 while (isspace(*s) || *s == ',') s++;
2466 if (*s == 0) break; /* End of header */
2468 ss = parse_find_address_end(s, FALSE);
2470 /* The terminator is a comma or end of header, but there may be white
2471 space preceding it (including newline for the last address). Move back
2472 past any white space so we can check against any cached envelope sender
2473 address verifications. */
2475 while (isspace(ss[-1])) ss--;
2479 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2480 (int)(endname - h->text), h->text, s);
2482 /* See if we have already verified this address as an envelope sender,
2483 and if so, use the previous answer. */
2485 vaddr = verify_checked_sender(s);
2487 if (vaddr != NULL && /* Previously checked */
2488 (callout <= 0 || /* No callout needed; OR */
2489 vaddr->special_action > 256)) /* Callout was done */
2491 new_ok = vaddr->special_action & 255;
2492 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2493 *ss = terminator; /* Restore shortened string */
2496 /* Otherwise we run the verification now. We must restore the shortened
2497 string before running the verification, so the headers are correct, in
2498 case there is any rewriting. */
2502 int start, end, domain;
2503 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2508 /* If we found an empty address, just carry on with the next one, but
2509 kill the message. */
2511 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2518 /* If verification failed because of a syntax error, fail this
2519 function, and ensure that the failing address gets added to the error
2522 if (address == NULL)
2525 while (ss > s && isspace(ss[-1])) ss--;
2526 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2527 "scanning for sender: %s in \"%.*s\"",
2528 endname - h->text, h->text, *log_msgptr, ss - s, s);
2534 /* Else go ahead with the sender verification. But it isn't *the*
2535 sender of the message, so set vopt_fake_sender to stop sender_address
2536 being replaced after rewriting or qualification. */
2540 vaddr = deliver_make_addr(address, FALSE);
2541 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2542 callout, callout_overall, callout_connect, se_mailfrom,
2547 /* We now have the result, either newly found, or cached. If we are
2548 giving out error details, set a specific user error. This means that the
2549 last of these will be returned to the user if all three fail. We do not
2550 set a log message - the generic one below will be used. */
2554 *verrno = vaddr->basic_errno;
2555 if (smtp_return_error_details)
2557 *user_msgptr = string_sprintf("Rejected after DATA: "
2558 "could not verify \"%.*s\" header address\n%s: %s",
2559 endname - h->text, h->text, vaddr->address, vaddr->message);
2563 /* Success or defer */
2572 if (new_ok == DEFER) yield = DEFER;
2574 /* Move on to any more addresses in the header */
2577 } /* Next address */
2579 parse_allow_group = FALSE;
2580 parse_found_group = FALSE;
2581 } /* Next header, unless done */
2582 } /* Next header type unless done */
2584 if (yield == FAIL && *log_msgptr == NULL)
2585 *log_msgptr = US"there is no valid sender in any header line";
2587 if (yield == DEFER && *log_msgptr == NULL)
2588 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2596 /*************************************************
2597 * Get RFC 1413 identification *
2598 *************************************************/
2600 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2601 the timeout is set to zero, then the query is not done. There may also be lists
2602 of hosts and nets which are exempt. To guard against malefactors sending
2603 non-printing characters which could, for example, disrupt a message's headers,
2604 make sure the string consists of printing characters only.
2607 port the port to connect to; usually this is IDENT_PORT (113), but when
2608 running in the test harness with -bh a different value is used.
2612 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2616 verify_get_ident(int port)
2618 int sock, host_af, qlen;
2619 int received_sender_port, received_interface_port, n;
2621 uschar buffer[2048];
2623 /* Default is no ident. Check whether we want to do an ident check for this
2626 sender_ident = NULL;
2627 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2630 DEBUG(D_ident) debug_printf("doing ident callback\n");
2632 /* Set up a connection to the ident port of the remote host. Bind the local end
2633 to the incoming interface address. If the sender host address is an IPv6
2634 address, the incoming interface address will also be IPv6. */
2636 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2637 sock = ip_socket(SOCK_STREAM, host_af);
2638 if (sock < 0) return;
2640 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2642 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2647 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2650 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2652 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2653 sender_host_address);
2657 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2658 sender_host_address, strerror(errno));
2663 /* Construct and send the query. */
2665 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2666 qlen = Ustrlen(buffer);
2667 if (send(sock, buffer, qlen, 0) < 0)
2669 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2673 /* Read a response line. We put it into the rest of the buffer, using several
2674 recv() calls if necessary. */
2682 int size = sizeof(buffer) - (p - buffer);
2684 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2685 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2686 if (count <= 0) goto END_OFF; /* Read error or EOF */
2688 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2689 generous, and accept a plain \n terminator as well. The only illegal
2692 for (pp = p; pp < p + count; pp++)
2694 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2697 if (pp[-1] == '\r') pp--;
2699 goto GOT_DATA; /* Break out of both loops */
2703 /* Reached the end of the data without finding \n. Let the loop continue to
2704 read some more, if there is room. */
2711 /* We have received a line of data. Check it carefully. It must start with the
2712 same two port numbers that we sent, followed by data as defined by the RFC. For
2715 12345 , 25 : USERID : UNIX :root
2717 However, the amount of white space may be different to what we sent. In the
2718 "osname" field there may be several sub-fields, comma separated. The data we
2719 actually want to save follows the third colon. Some systems put leading spaces
2720 in it - we discard those. */
2722 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2723 &received_interface_port, &n) != 2 ||
2724 received_sender_port != sender_host_port ||
2725 received_interface_port != interface_port)
2728 p = buffer + qlen + n;
2729 while(isspace(*p)) p++;
2730 if (*p++ != ':') goto END_OFF;
2731 while(isspace(*p)) p++;
2732 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2734 while(isspace(*p)) p++;
2735 if (*p++ != ':') goto END_OFF;
2736 while (*p != 0 && *p != ':') p++;
2737 if (*p++ == 0) goto END_OFF;
2738 while(isspace(*p)) p++;
2739 if (*p == 0) goto END_OFF;
2741 /* The rest of the line is the data we want. We turn it into printing
2742 characters when we save it, so that it cannot mess up the format of any logging
2743 or Received: lines into which it gets inserted. We keep a maximum of 127
2746 sender_ident = string_printing(string_copyn(p, 127));
2747 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2757 /*************************************************
2758 * Match host to a single host-list item *
2759 *************************************************/
2761 /* This function compares a host (name or address) against a single item
2762 from a host list. The host name gets looked up if it is needed and is not
2763 already known. The function is called from verify_check_this_host() via
2764 match_check_list(), which is why most of its arguments are in a single block.
2767 arg the argument block (see below)
2768 ss the host-list item
2769 valueptr where to pass back looked up data, or NULL
2770 error for error message when returning ERROR
2773 host_name (a) the host name, or
2774 (b) NULL, implying use sender_host_name and
2775 sender_host_aliases, looking them up if required, or
2776 (c) the empty string, meaning that only IP address matches
2778 host_address the host address
2779 host_ipv4 the IPv4 address taken from an IPv6 one
2783 DEFER lookup deferred
2784 ERROR (a) failed to find the host name or IP address, or
2785 (b) unknown lookup type specified, or
2786 (c) host name encountered when only IP addresses are
2791 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2793 check_host_block *cb = (check_host_block *)arg;
2796 BOOL iplookup = FALSE;
2797 BOOL isquery = FALSE;
2798 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2803 /* Optimize for the special case when the pattern is "*". */
2805 if (*ss == '*' && ss[1] == 0) return OK;
2807 /* If the pattern is empty, it matches only in the case when there is no host -
2808 this can occur in ACL checking for SMTP input using the -bs option. In this
2809 situation, the host address is the empty string. */
2811 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2812 if (*ss == 0) return FAIL;
2814 /* If the pattern is precisely "@" then match against the primary host name,
2815 provided that host name matching is permitted; if it's "@[]" match against the
2816 local host's IP addresses. */
2822 if (isiponly) return ERROR;
2823 ss = primary_hostname;
2825 else if (Ustrcmp(ss, "@[]") == 0)
2827 ip_address_item *ip;
2828 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2829 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2834 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2835 a (possibly masked) comparision with the current IP address. */
2837 if (string_is_ip_address(ss, &maskoffset) != 0)
2838 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2840 /* The pattern is not an IP address. A common error that people make is to omit
2841 one component of an IPv4 address, either by accident, or believing that, for
2842 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,
2843 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2844 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2845 ancient specification.) To aid in debugging these cases, we give a specific
2846 error if the pattern contains only digits and dots or contains a slash preceded
2847 only by digits and dots (a slash at the start indicates a file name and of
2848 course slashes may be present in lookups, but not preceded only by digits and
2851 for (t = ss; isdigit(*t) || *t == '.'; t++);
2852 if (*t == 0 || (*t == '/' && t != ss))
2854 *error = US"malformed IPv4 address or address mask";
2858 /* See if there is a semicolon in the pattern */
2860 semicolon = Ustrchr(ss, ';');
2862 /* If we are doing an IP address only match, then all lookups must be IP
2863 address lookups, even if there is no "net-". */
2867 iplookup = semicolon != NULL;
2870 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2871 a lookup on a masked IP network, in textual form. We obey this code even if we
2872 have already set iplookup, so as to skip over the "net-" prefix and to set the
2873 mask length. The net- stuff really only applies to single-key lookups where the
2874 key is implicit. For query-style lookups the key is specified in the query.
2875 From release 4.30, the use of net- for query style is no longer needed, but we
2876 retain it for backward compatibility. */
2878 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2881 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2882 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2883 iplookup = (*t++ == '-');
2887 /* Do the IP address lookup if that is indeed what we have */
2895 uschar *filename, *key, *result;
2898 /* Find the search type */
2900 search_type = search_findtype(t, semicolon - t);
2902 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2903 search_error_message);
2905 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2906 is no file name, and the "key" is just the query. For query-style with a file
2907 name, we have to fish the file off the start of the query. For a single-key
2908 lookup, the key is the current IP address, masked appropriately, and
2909 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2910 dot separators instead of colons, except when the lookup type is "iplsearch".
2913 if (mac_islookup(search_type, lookup_absfilequery))
2915 filename = semicolon + 1;
2917 while (*key != 0 && !isspace(*key)) key++;
2918 filename = string_copyn(filename, key - filename);
2919 while (isspace(*key)) key++;
2921 else if (mac_islookup(search_type, lookup_querystyle))
2924 key = semicolon + 1;
2926 else /* Single-key style */
2928 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2930 insize = host_aton(cb->host_address, incoming);
2931 host_mask(insize, incoming, mlen);
2932 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2934 filename = semicolon + 1;
2937 /* Now do the actual lookup; note that there is no search_close() because
2938 of the caching arrangements. */
2940 handle = search_open(filename, search_type, 0, NULL, NULL);
2941 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2942 search_error_message);
2943 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2944 if (valueptr != NULL) *valueptr = result;
2945 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2948 /* The pattern is not an IP address or network reference of any kind. That is,
2949 it is a host name pattern. If this is an IP only match, there's an error in the
2954 *error = US"cannot match host name in match_ip list";
2958 /* Check the characters of the pattern to see if they comprise only letters,
2959 digits, full stops, and hyphens (the constituents of domain names). Allow
2960 underscores, as they are all too commonly found. Sigh. Also, if
2961 allow_utf8_domains is set, allow top-bit characters. */
2963 for (t = ss; *t != 0; t++)
2964 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2965 (!allow_utf8_domains || *t < 128)) break;
2967 /* If the pattern is a complete domain name, with no fancy characters, look up
2968 its IP address and match against that. Note that a multi-homed host will add
2969 items to the chain. */
2980 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2981 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2984 for (hh = &h; hh != NULL; hh = hh->next)
2986 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2990 if (rc == HOST_FIND_AGAIN) return DEFER;
2991 *error = string_sprintf("failed to find IP address for %s", ss);
2995 /* Almost all subsequent comparisons require the host name, and can be done
2996 using the general string matching function. When this function is called for
2997 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2998 must use sender_host_name and its aliases, looking them up if necessary. */
3000 if (cb->host_name != NULL) /* Explicit host name given */
3001 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3004 /* Host name not given; in principle we need the sender host name and its
3005 aliases. However, for query-style lookups, we do not need the name if the
3006 query does not contain $sender_host_name. From release 4.23, a reference to
3007 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3010 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3013 int partial, affixlen, starflags, id;
3016 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3019 if (id < 0) /* Unknown lookup type */
3021 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3022 search_error_message, ss);
3025 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3030 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3033 case DEFER: return DEFER;
3034 default: return FAIL;
3038 /* Not a query-style lookup; must ensure the host name is present, and then we
3039 do a check on the name and all its aliases. */
3041 if (sender_host_name == NULL)
3043 HDEBUG(D_host_lookup)
3044 debug_printf("sender host name required, to match against %s\n", ss);
3045 if (host_lookup_failed || host_name_lookup() != OK)
3047 *error = string_sprintf("failed to find host name for %s",
3048 sender_host_address);;
3051 host_build_sender_fullhost();
3054 /* Match on the sender host name, using the general matching function */
3056 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3060 case DEFER: return DEFER;
3063 /* If there are aliases, try matching on them. */
3065 aliases = sender_host_aliases;
3066 while (*aliases != NULL)
3068 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3071 case DEFER: return DEFER;
3080 /*************************************************
3081 * Check a specific host matches a host list *
3082 *************************************************/
3084 /* This function is passed a host list containing items in a number of
3085 different formats and the identity of a host. Its job is to determine whether
3086 the given host is in the set of hosts defined by the list. The host name is
3087 passed as a pointer so that it can be looked up if needed and not already
3088 known. This is commonly the case when called from verify_check_host() to check
3089 an incoming connection. When called from elsewhere the host name should usually
3092 This function is now just a front end to match_check_list(), which runs common
3093 code for scanning a list. We pass it the check_host() function to perform a
3097 listptr pointer to the host list
3098 cache_bits pointer to cache for named lists, or NULL
3099 host_name the host name or NULL, implying use sender_host_name and
3100 sender_host_aliases, looking them up if required
3101 host_address the IP address
3102 valueptr if not NULL, data from a lookup is passed back here
3104 Returns: OK if the host is in the defined set
3105 FAIL if the host is not in the defined set,
3106 DEFER if a data lookup deferred (not a host lookup)
3108 If the host name was needed in order to make a comparison, and could not be
3109 determined from the IP address, the result is FAIL unless the item
3110 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3113 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
3114 uschar *host_name, uschar *host_address, uschar **valueptr)
3117 unsigned int *local_cache_bits = cache_bits;
3118 uschar *save_host_address = deliver_host_address;
3119 check_host_block cb;
3120 cb.host_name = host_name;
3121 cb.host_address = host_address;
3123 if (valueptr != NULL) *valueptr = NULL;
3125 /* If the host address starts off ::ffff: it is an IPv6 address in
3126 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3129 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3130 host_address + 7 : host_address;
3132 /* During the running of the check, put the IP address into $host_address. In
3133 the case of calls from the smtp transport, it will already be there. However,
3134 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3135 the safe side, any existing setting is preserved, though as I write this
3136 (November 2004) I can't see any cases where it is actually needed. */
3138 deliver_host_address = host_address;
3139 rc = match_check_list(
3140 listptr, /* the list */
3141 0, /* separator character */
3142 &hostlist_anchor, /* anchor pointer */
3143 &local_cache_bits, /* cache pointer */
3144 check_host, /* function for testing */
3145 &cb, /* argument for function */
3146 MCL_HOST, /* type of check */
3147 (host_address == sender_host_address)?
3148 US"host" : host_address, /* text for debugging */
3149 valueptr); /* where to pass back data */
3150 deliver_host_address = save_host_address;
3157 /*************************************************
3158 * Check the remote host matches a list *
3159 *************************************************/
3161 /* This is a front end to verify_check_this_host(), created because checking
3162 the remote host is a common occurrence. With luck, a good compiler will spot
3163 the tail recursion and optimize it. If there's no host address, this is
3164 command-line SMTP input - check against an empty string for the address.
3167 listptr pointer to the host list
3169 Returns: the yield of verify_check_this_host(),
3170 i.e. OK, FAIL, or DEFER
3174 verify_check_host(uschar **listptr)
3176 return verify_check_this_host(listptr, sender_host_cache, NULL,
3177 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3184 /*************************************************
3185 * Invert an IP address *
3186 *************************************************/
3188 /* Originally just used for DNS xBL lists, now also used for the
3189 reverse_ip expansion operator.
3192 buffer where to put the answer
3193 address the address to invert
3197 invert_address(uschar *buffer, uschar *address)
3200 uschar *bptr = buffer;
3202 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3203 to the IPv4 part only. */
3205 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3207 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3210 if (host_aton(address, bin) == 1)
3214 for (i = 0; i < 4; i++)
3216 sprintf(CS bptr, "%d.", x & 255);
3217 while (*bptr) bptr++;
3222 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3223 in any DNS black lists, and the format in which they will be looked up is
3224 unknown. This is just a guess. */
3230 for (j = 3; j >= 0; j--)
3233 for (i = 0; i < 8; i++)
3235 sprintf(CS bptr, "%x.", x & 15);
3236 while (*bptr) bptr++;
3243 /* Remove trailing period -- this is needed so that both arbitrary
3244 dnsbl keydomains and inverted addresses may be combined with the
3245 same format string, "%s.%s" */
3252 /*************************************************
3253 * Perform a single dnsbl lookup *
3254 *************************************************/
3256 /* This function is called from verify_check_dnsbl() below. It is also called
3257 recursively from within itself when domain and domain_txt are different
3258 pointers, in order to get the TXT record from the alternate domain.
3261 domain the outer dnsbl domain
3262 domain_txt alternate domain to lookup TXT record on success; when the
3263 same domain is to be used, domain_txt == domain (that is,
3264 the pointers must be identical, not just the text)
3265 keydomain the current keydomain (for debug message)
3266 prepend subdomain to lookup (like keydomain, but
3267 reversed if IP address)
3268 iplist the list of matching IP addresses, or NULL for "any"
3269 bitmask true if bitmask matching is wanted
3270 match_type condition for 'succeed' result
3271 0 => Any RR in iplist (=)
3272 1 => No RR in iplist (!=)
3273 2 => All RRs in iplist (==)
3274 3 => Some RRs not in iplist (!==)
3275 the two bits are defined as MT_NOT and MT_ALL
3276 defer_return what to return for a defer
3278 Returns: OK if lookup succeeded
3283 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3284 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3290 dnsbl_cache_block *cb;
3291 int old_pool = store_pool;
3292 uschar query[256]; /* DNS domain max length */
3294 /* Construct the specific query domainname */
3296 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3298 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3299 "(ignored): %s...", query);
3303 /* Look for this query in the cache. */
3305 t = tree_search(dnsbl_cache, query);
3307 /* If not cached from a previous lookup, we must do a DNS lookup, and
3308 cache the result in permanent memory. */
3312 store_pool = POOL_PERM;
3314 /* Set up a tree entry to cache the lookup */
3316 t = store_get(sizeof(tree_node) + Ustrlen(query));
3317 Ustrcpy(t->name, query);
3318 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3319 (void)tree_insertnode(&dnsbl_cache, t);
3321 /* Do the DNS loopup . */
3323 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3324 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3325 cb->text_set = FALSE;
3329 /* If the lookup succeeded, cache the RHS address. The code allows for
3330 more than one address - this was for complete generality and the possible
3331 use of A6 records. However, A6 records have been reduced to experimental
3332 status (August 2001) and may die out. So they may never get used at all,
3333 let alone in dnsbl records. However, leave the code here, just in case.
3335 Quite apart from one A6 RR generating multiple addresses, there are DNS
3336 lists that return more than one A record, so we must handle multiple
3337 addresses generated in that way as well. */
3339 if (cb->rc == DNS_SUCCEED)
3342 dns_address **addrp = &(cb->rhs);
3343 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3345 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3347 if (rr->type == T_A)
3349 dns_address *da = dns_address_from_rr(&dnsa, rr);
3353 while (da->next != NULL) da = da->next;
3354 addrp = &(da->next);
3359 /* If we didn't find any A records, change the return code. This can
3360 happen when there is a CNAME record but there are no A records for what
3363 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3366 store_pool = old_pool;
3369 /* Previous lookup was cached */
3373 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3377 /* We now have the result of the DNS lookup, either newly done, or cached
3378 from a previous call. If the lookup succeeded, check against the address
3379 list if there is one. This may be a positive equality list (introduced by
3380 "="), a negative equality list (introduced by "!="), a positive bitmask
3381 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3383 if (cb->rc == DNS_SUCCEED)
3385 dns_address *da = NULL;
3386 uschar *addlist = cb->rhs->address;
3388 /* For A and AAAA records, there may be multiple addresses from multiple
3389 records. For A6 records (currently not expected to be used) there may be
3390 multiple addresses from a single record. */
3392 for (da = cb->rhs->next; da != NULL; da = da->next)
3393 addlist = string_sprintf("%s, %s", addlist, da->address);
3395 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3398 /* Address list check; this can be either for equality, or via a bitmask.
3399 In the latter case, all the bits must match. */
3403 for (da = cb->rhs; da != NULL; da = da->next)
3407 uschar *ptr = iplist;
3410 /* Handle exact matching */
3414 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3416 if (Ustrcmp(CS da->address, ip) == 0) break;
3420 /* Handle bitmask matching */
3427 /* At present, all known DNS blocking lists use A records, with
3428 IPv4 addresses on the RHS encoding the information they return. I
3429 wonder if this will linger on as the last vestige of IPv4 when IPv6
3430 is ubiquitous? Anyway, for now we use paranoia code to completely
3431 ignore IPv6 addresses. The default mask is 0, which always matches.
3432 We change this only for IPv4 addresses in the list. */
3434 if (host_aton(da->address, address) == 1) mask = address[0];
3436 /* Scan the returned addresses, skipping any that are IPv6 */
3438 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3440 if (host_aton(ip, address) != 1) continue;
3441 if ((address[0] & mask) == address[0]) break;
3447 (a) An IP address in an any ('=') list matched, or
3448 (b) No IP address in an all ('==') list matched
3450 then we're done searching. */
3452 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3455 /* If da == NULL, either
3457 (a) No IP address in an any ('=') list matched, or
3458 (b) An IP address in an all ('==') list didn't match
3460 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3463 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3471 res = US"was no match";
3474 res = US"was an exclude match";
3477 res = US"was an IP address that did not match";
3480 res = US"were no IP addresses that did not match";
3483 debug_printf("=> but we are not accepting this block class because\n");
3484 debug_printf("=> there %s for %s%c%s\n",
3486 ((match_type & MT_ALL) == 0)? "" : "=",
3487 bitmask? '&' : '=', iplist);
3493 /* Either there was no IP list, or the record matched, implying that the
3494 domain is on the list. We now want to find a corresponding TXT record. If an
3495 alternate domain is specified for the TXT record, call this function
3496 recursively to look that up; this has the side effect of re-checking that
3497 there is indeed an A record at the alternate domain. */
3499 if (domain_txt != domain)
3500 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3501 FALSE, match_type, defer_return);
3503 /* If there is no alternate domain, look up a TXT record in the main domain
3504 if it has not previously been cached. */
3508 cb->text_set = TRUE;
3509 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3512 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3514 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3515 if (rr->type == T_TXT) break;
3518 int len = (rr->data)[0];
3519 if (len > 511) len = 127;
3520 store_pool = POOL_PERM;
3521 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3522 store_pool = old_pool;
3527 dnslist_value = addlist;
3528 dnslist_text = cb->text;
3532 /* There was a problem with the DNS lookup */
3534 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3536 log_write(L_dnslist_defer, LOG_MAIN,
3537 "DNS list lookup defer (probably timeout) for %s: %s", query,
3538 (defer_return == OK)? US"assumed in list" :
3539 (defer_return == FAIL)? US"assumed not in list" :
3540 US"returned DEFER");
3541 return defer_return;
3544 /* No entry was found in the DNS; continue for next domain */
3548 debug_printf("DNS lookup for %s failed\n", query);
3549 debug_printf("=> that means %s is not listed at %s\n",
3559 /*************************************************
3560 * Check host against DNS black lists *
3561 *************************************************/
3563 /* This function runs checks against a list of DNS black lists, until one
3564 matches. Each item on the list can be of the form
3566 domain=ip-address/key
3568 The domain is the right-most domain that is used for the query, for example,
3569 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3570 if the DNS lookup returns a matching IP address. Several addresses may be
3571 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3573 If no key is given, what is looked up in the domain is the inverted IP address
3574 of the current client host. If a key is given, it is used to construct the
3575 domain for the lookup. For example:
3577 dsn.rfc-ignorant.org/$sender_address_domain
3579 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3580 then we check for a TXT record for an error message, and if found, save its
3581 value in $dnslist_text. We also cache everything in a tree, to optimize
3584 The TXT record is normally looked up in the same domain as the A record, but
3585 when many lists are combined in a single DNS domain, this will not be a very
3586 specific message. It is possible to specify a different domain for looking up
3587 TXT records; this is given before the main domain, comma-separated. For
3590 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3591 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3593 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3595 Note: an address for testing RBL is 192.203.178.39
3596 Note: an address for testing DUL is 192.203.178.4
3597 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3600 listptr the domain/address/data list
3602 Returns: OK successful lookup (i.e. the address is on the list), or
3603 lookup deferred after +include_unknown
3604 FAIL name not found, or no data found for the given type, or
3605 lookup deferred after +exclude_unknown (default)
3606 DEFER lookup failure, if +defer_unknown was set
3610 verify_check_dnsbl(uschar **listptr)
3613 int defer_return = FAIL;
3614 uschar *list = *listptr;
3617 uschar buffer[1024];
3618 uschar revadd[128]; /* Long enough for IPv6 address */
3620 /* Indicate that the inverted IP address is not yet set up */
3624 /* In case this is the first time the DNS resolver is being used. */
3626 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3628 /* Loop through all the domains supplied, until something matches */
3630 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3633 BOOL bitmask = FALSE;
3640 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3642 /* Deal with special values that change the behaviour on defer */
3644 if (domain[0] == '+')
3646 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3647 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3648 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3650 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3655 /* See if there's explicit data to be looked up */
3657 key = Ustrchr(domain, '/');
3658 if (key != NULL) *key++ = 0;
3660 /* See if there's a list of addresses supplied after the domain name. This is
3661 introduced by an = or a & character; if preceded by = we require all matches
3662 and if preceded by ! we invert the result. */
3664 iplist = Ustrchr(domain, '=');
3668 iplist = Ustrchr(domain, '&');
3671 if (iplist != NULL) /* Found either = or & */
3673 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3675 match_type |= MT_NOT;
3679 *iplist++ = 0; /* Terminate domain, move on */
3681 /* If we found = (bitmask == FALSE), check for == or =& */
3683 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3685 bitmask = *iplist++ == '&';
3686 match_type |= MT_ALL;
3690 /* If there is a comma in the domain, it indicates that a second domain for
3691 looking up TXT records is provided, before the main domain. Otherwise we must
3692 set domain_txt == domain. */
3694 domain_txt = domain;
3695 comma = Ustrchr(domain, ',');
3702 /* Check that what we have left is a sensible domain name. There is no reason
3703 why these domains should in fact use the same syntax as hosts and email
3704 domains, but in practice they seem to. However, there is little point in
3705 actually causing an error here, because that would no doubt hold up incoming
3706 mail. Instead, I'll just log it. */
3708 for (s = domain; *s != 0; s++)
3710 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3712 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3713 "strange characters - is this right?", domain);
3718 /* Check the alternate domain if present */
3720 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3722 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3724 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3725 "strange characters - is this right?", domain_txt);
3730 /* If there is no key string, construct the query by adding the domain name
3731 onto the inverted host address, and perform a single DNS lookup. */
3735 if (sender_host_address == NULL) return FAIL; /* can never match */
3736 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3737 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3738 iplist, bitmask, match_type, defer_return);
3741 dnslist_domain = string_copy(domain_txt);
3742 dnslist_matched = string_copy(sender_host_address);
3743 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3744 sender_host_address, dnslist_domain);
3746 if (rc != FAIL) return rc; /* OK or DEFER */
3749 /* If there is a key string, it can be a list of domains or IP addresses to
3750 be concatenated with the main domain. */
3757 uschar keybuffer[256];
3758 uschar keyrevadd[128];
3760 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3761 sizeof(keybuffer))) != NULL)
3763 uschar *prepend = keydomain;
3765 if (string_is_ip_address(keydomain, NULL) != 0)
3767 invert_address(keyrevadd, keydomain);
3768 prepend = keyrevadd;
3771 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3772 bitmask, match_type, defer_return);
3776 dnslist_domain = string_copy(domain_txt);
3777 dnslist_matched = string_copy(keydomain);
3778 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3779 keydomain, dnslist_domain);
3783 /* If the lookup deferred, remember this fact. We keep trying the rest
3784 of the list to see if we get a useful result, and if we don't, we return
3785 DEFER at the end. */
3787 if (rc == DEFER) defer = TRUE;
3788 } /* continue with next keystring domain/address */
3790 if (defer) return DEFER;
3792 } /* continue with next dnsdb outer domain */
3799 /* End of verify.c */