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 uschar inbuffer[4096];
430 uschar outbuffer[1024];
431 uschar responsebuffer[4096];
433 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
434 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
436 /* Skip this host if we don't have an IP address for it. */
438 if (host->address == NULL)
440 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
445 /* Check the overall callout timeout */
447 if (time(NULL) - callout_start_time >= callout_overall)
449 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
453 /* Set IPv4 or IPv6 */
455 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
457 /* Expand and interpret the interface and port strings. The latter will not
458 be used if there is a host-specific port (e.g. from a manualroute router).
459 This has to be delayed till now, because they may expand differently for
460 different hosts. If there's a failure, log it, but carry on with the
463 deliver_host = host->name;
464 deliver_host_address = host->address;
465 deliver_host_port = host->port;
466 deliver_domain = addr->domain;
468 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
470 !smtp_get_port(tf->port, addr, &port, US"callout"))
471 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
474 /* Set HELO string according to the protocol */
475 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
476 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
479 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
481 /* Set up the buffer for reading SMTP response packets. */
483 inblock.buffer = inbuffer;
484 inblock.buffersize = sizeof(inbuffer);
485 inblock.ptr = inbuffer;
486 inblock.ptrend = inbuffer;
488 /* Set up the buffer for holding SMTP commands while pipelining */
490 outblock.buffer = outbuffer;
491 outblock.buffersize = sizeof(outbuffer);
492 outblock.ptr = outbuffer;
493 outblock.cmd_count = 0;
494 outblock.authenticating = FALSE;
496 /* Reset the parameters of a TLS session */
497 tls_out.cipher = tls_out.peerdn = NULL;
499 /* Connect to the host; on failure, just loop for the next one, but we
500 set the error for the last one. Use the callout_connect timeout. */
502 tls_retry_connection:
504 inblock.sock = outblock.sock =
505 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL
506 #ifdef EXPERIMENTAL_TPDA
507 /*XXX tpda action? NULL for now. */
511 /* reconsider DSCP here */
512 if (inblock.sock < 0)
514 addr->message = string_sprintf("could not connect to %s [%s]: %s",
515 host->name, host->address, strerror(errno));
516 deliver_host = deliver_host_address = NULL;
517 deliver_domain = save_deliver_domain;
521 /* Expand the helo_data string to find the host name to use. */
523 if (tf->helo_data != NULL)
525 uschar *s = expand_string(tf->helo_data);
527 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
528 "helo_data value for callout: %s", addr->address,
529 expand_string_message);
530 else active_hostname = s;
533 /* Wait for initial response, and send HELO. The smtp_write_command()
534 function leaves its command in big_buffer. This is used in error responses.
535 Initialize it in case the connection is rejected. */
537 Ustrcpy(big_buffer, "initial connection");
539 /* Unless ssl-on-connect, wait for the initial greeting */
543 if (!smtps || (smtps && tls_out.active >= 0))
546 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
547 goto RESPONSE_FAILED;
549 #ifdef EXPERIMENTAL_TPDA
550 if (tpda_raise_event(addr->transport->tpda_event_action,
551 US"smtp:connect", responsebuffer) == DEFER)
553 /* Logging? Debug? */
554 goto RESPONSE_FAILED;
559 /* Not worth checking greeting line for ESMTP support */
560 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
561 host->name, host->address, NULL) != OK))
563 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
568 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
571 ob->tls_tempfail_tryclear = FALSE;
573 else /* all other cases */
578 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
579 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
581 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
583 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
586 goto RESPONSE_FAILED;
592 goto esmtp_retry; /* fallback to HELO */
595 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
597 if (esmtp && !suppress_tls && tls_out.active < 0)
599 if (regex_STARTTLS == NULL) regex_STARTTLS =
600 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
602 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
603 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
610 /* If TLS is available on this connection attempt to
611 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
612 send another EHLO - the server may give a different answer in secure mode. We
613 use a separate buffer for reading the response to STARTTLS so that if it is
614 negative, the original EHLO data is available for subsequent analysis, should
615 the client not be required to use TLS. If the response is bad, copy the buffer
616 for error analysis. */
620 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
621 host->address, NULL) != OK &&
622 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
623 host->address, NULL) != OK
626 uschar buffer2[4096];
628 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
631 /* If there is an I/O error, transmission of this message is deferred. If
632 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
633 false, we also defer. However, if there is a temporary rejection of STARTTLS
634 and tls_tempfail_tryclear is true, or if there is an outright rejection of
635 STARTTLS, we carry on. This means we will try to send the message in clear,
636 unless the host is in hosts_require_tls (tested below). */
638 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
639 ob->command_timeout))
641 if (errno != 0 || buffer2[0] == 0 ||
642 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
644 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
646 goto RESPONSE_FAILED;
650 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
653 int oldtimeout = ob->command_timeout;
656 ob->command_timeout = callout;
657 rc = tls_client_start(inblock.sock, host, addr, addr->transport);
658 ob->command_timeout = oldtimeout;
660 /* TLS negotiation failed; give an error. Try in clear on a new connection,
661 if the options permit it for this host. */
665 && ob->tls_tempfail_tryclear
667 && verify_check_this_host(&(ob->hosts_require_tls), NULL,
668 host->name, host->address, NULL) != OK
669 #ifdef EXPERIMENTAL_DANE
670 && verify_check_this_host(&(ob->hosts_require_dane), NULL,
671 host->name, host->address, NULL) != OK
675 (void)close(inblock.sock);
676 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
677 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
679 goto tls_retry_connection;
681 /*save_errno = ERRNO_TLSFAILURE;*/
682 /*message = US"failure while setting up TLS session";*/
688 /* TLS session is set up. Copy info for logging. */
689 addr->cipher = tls_out.cipher;
690 addr->peerdn = tls_out.peerdn;
692 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
694 goto smtps_redo_greeting;
696 /* For STARTTLS we need to redo EHLO */
701 /* If the host is required to use a secure channel, ensure that we have one. */
702 if (tls_out.active < 0)
703 if ( verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
704 host->address, NULL) == OK
705 #ifdef EXPERIMENTAL_DANE
706 || verify_check_this_host(&(ob->hosts_require_dane), NULL, host->name,
707 host->address, NULL) == OK
711 /*save_errno = ERRNO_TLSREQUIRED;*/
712 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
713 host->name, host->address,
714 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
719 #endif /*SUPPORT_TLS*/
721 done = TRUE; /* so far so good; have response to HELO */
723 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
725 /* For now, transport_filter by cutthrough-delivery is not supported */
726 /* Need proper integration with the proper transport mechanism. */
727 if (cutthrough_delivery)
729 if (addr->transport->filter_command)
731 cutthrough_delivery= FALSE;
732 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
737 cutthrough_delivery= FALSE;
738 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
747 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
749 /* Failure to accept HELO is cached; this blocks the whole domain for all
750 senders. I/O errors and defer responses are not cached. */
754 *failure_ptr = US"mail"; /* At or before MAIL */
755 if (errno == 0 && responsebuffer[0] == '5')
757 setflag(addr, af_verify_nsfail);
758 new_domain_record.result = ccache_reject;
762 /* If we haven't authenticated, but are required to, give up. */
765 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
766 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
768 /* Copy AUTH info for logging */
769 ( (addr->authenticator = client_authenticator),
770 (addr->auth_id = client_authenticated_id),
772 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
773 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
776 ( (addr->auth_sndr = client_authenticated_sender),
778 /* Send the MAIL command */
779 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
780 from_address, responsebuffer) >= 0)
783 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
786 deliver_host = deliver_host_address = NULL;
787 deliver_domain = save_deliver_domain;
789 /* If the host does not accept MAIL FROM:<>, arrange to cache this
790 information, but again, don't record anything for an I/O error or a defer. Do
791 not cache rejections of MAIL when a non-empty sender has been used, because
792 that blocks the whole domain for all senders. */
796 *failure_ptr = US"mail"; /* At or before MAIL */
797 if (errno == 0 && responsebuffer[0] == '5')
799 setflag(addr, af_verify_nsfail);
800 if (from_address[0] == 0)
801 new_domain_record.result = ccache_reject_mfnull;
805 /* Otherwise, proceed to check a "random" address (if required), then the
806 given address, and the postmaster address (if required). Between each check,
807 issue RSET, because some servers accept only one recipient after MAIL
810 Before doing this, set the result in the domain cache record to "accept",
811 unless its previous value was ccache_reject_mfnull. In that case, the domain
812 rejects MAIL FROM:<> and we want to continue to remember that. When that is
813 the case, we have got here only in the case of a recipient verification with
814 a non-null sender. */
818 new_domain_record.result =
819 (old_domain_cache_result == ccache_reject_mfnull)?
820 ccache_reject_mfnull: ccache_accept;
822 /* Do the random local part check first */
824 if (random_local_part != NULL)
826 uschar randombuffer[1024];
828 smtp_write_command(&outblock, FALSE,
829 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
830 addr->domain) >= 0 &&
831 smtp_read_response(&inblock, randombuffer,
832 sizeof(randombuffer), '2', callout);
834 /* Remember when we last did a random test */
836 new_domain_record.random_stamp = time(NULL);
838 /* If accepted, we aren't going to do any further tests below. */
842 new_domain_record.random_result = ccache_accept;
845 /* Otherwise, cache a real negative response, and get back to the right
846 state to send RCPT. Unless there's some problem such as a dropped
847 connection, we expect to succeed, because the commands succeeded above. */
851 if (randombuffer[0] == '5')
852 new_domain_record.random_result = ccache_reject;
855 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
856 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
859 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
860 from_address) >= 0 &&
861 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
864 else done = FALSE; /* Some timeout/connection problem */
867 /* If the host is accepting all local parts, as determined by the "random"
868 check, we don't need to waste time doing any further checking. */
870 if (new_domain_record.random_result != ccache_accept && done)
872 /* Get the rcpt_include_affixes flag from the transport if there is one,
873 but assume FALSE if there is not. */
876 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
877 transport_rcpt_address(addr,
878 (addr->transport == NULL)? FALSE :
879 addr->transport->rcpt_include_affixes)) >= 0 &&
880 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
884 new_address_record.result = ccache_accept;
885 else if (errno == 0 && responsebuffer[0] == '5')
887 *failure_ptr = US"recipient";
888 new_address_record.result = ccache_reject;
891 /* Do postmaster check if requested; if a full check is required, we
892 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
894 if (done && pm_mailfrom != NULL)
896 /*XXX not suitable for cutthrough - sequencing problems */
897 cutthrough_delivery= FALSE;
898 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
901 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
902 smtp_read_response(&inblock, responsebuffer,
903 sizeof(responsebuffer), '2', callout) &&
905 smtp_write_command(&outblock, FALSE,
906 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
907 smtp_read_response(&inblock, responsebuffer,
908 sizeof(responsebuffer), '2', callout) &&
910 /* First try using the current domain */
913 smtp_write_command(&outblock, FALSE,
914 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
915 smtp_read_response(&inblock, responsebuffer,
916 sizeof(responsebuffer), '2', callout)
921 /* If that doesn't work, and a full check is requested,
922 try without the domain. */
925 (options & vopt_callout_fullpm) != 0 &&
926 smtp_write_command(&outblock, FALSE,
927 "RCPT TO:<postmaster>\r\n") >= 0 &&
928 smtp_read_response(&inblock, responsebuffer,
929 sizeof(responsebuffer), '2', callout)
932 /* Sort out the cache record */
934 new_domain_record.postmaster_stamp = time(NULL);
937 new_domain_record.postmaster_result = ccache_accept;
938 else if (errno == 0 && responsebuffer[0] == '5')
940 *failure_ptr = US"postmaster";
941 setflag(addr, af_verify_pmfail);
942 new_domain_record.postmaster_result = ccache_reject;
945 } /* Random not accepted */
946 } /* MAIL FROM: accepted */
948 /* For any failure of the main check, other than a negative response, we just
949 close the connection and carry on. We can identify a negative response by the
950 fact that errno is zero. For I/O errors it will be non-zero
952 Set up different error texts for logging and for sending back to the caller
953 as an SMTP response. Log in all cases, using a one-line format. For sender
954 callouts, give a full response to the caller, but for recipient callouts,
955 don't give the IP address because this may be an internal host whose identity
956 is not to be widely broadcast. */
960 if (errno == ETIMEDOUT)
962 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
967 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
970 string_sprintf("response to \"%s\" from %s [%s] was: %s",
971 big_buffer, host->name, host->address,
972 string_printing(responsebuffer));
974 addr->user_message = is_recipient?
975 string_sprintf("Callout verification failed:\n%s", responsebuffer)
977 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
978 host->address, big_buffer, responsebuffer);
980 /* Hard rejection ends the process */
982 if (responsebuffer[0] == '5') /* Address rejected */
990 /* End the SMTP conversation and close the connection. */
992 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
993 and we have no cutthrough conn so far
994 here is where we want to leave the conn open */
995 if ( cutthrough_delivery
998 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
999 && !random_local_part
1001 && cutthrough_fd < 0
1004 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
1005 cutthrough_addr = *addr; /* Save the address_item for later logging */
1006 cutthrough_addr.next = NULL;
1007 cutthrough_addr.host_used = store_get(sizeof(host_item));
1008 cutthrough_addr.host_used->name = host->name;
1009 cutthrough_addr.host_used->address = host->address;
1010 cutthrough_addr.host_used->port = port;
1012 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
1013 ctblock.buffer = ctbuffer;
1014 ctblock.buffersize = sizeof(ctbuffer);
1015 ctblock.ptr = ctbuffer;
1016 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1017 ctblock.sock = cutthrough_fd;
1021 /* Ensure no cutthrough on multiple address verifies */
1022 if (options & vopt_callout_recipsender)
1023 cancel_cutthrough_connection("multiple verify calls");
1024 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1027 tls_close(FALSE, TRUE);
1029 (void)close(inblock.sock);
1030 #ifdef EXPERIMENTAL_TPDA
1031 (void) tpda_raise_event(addr->transport->tpda_event_action,
1032 US"tcp:close", NULL);
1036 } /* Loop through all hosts, while !done */
1039 /* If we get here with done == TRUE, a successful callout happened, and yield
1040 will be set OK or FAIL according to the response to the RCPT command.
1041 Otherwise, we looped through the hosts but couldn't complete the business.
1042 However, there may be domain-specific information to cache in both cases.
1044 The value of the result field in the new_domain record is ccache_unknown if
1045 there was an error before or with MAIL FROM:, and errno was not zero,
1046 implying some kind of I/O error. We don't want to write the cache in that case.
1047 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1049 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1051 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1054 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1058 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1059 (int)sizeof(dbdata_callout_cache));
1060 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1061 " result=%d postmaster=%d random=%d\n",
1062 new_domain_record.result,
1063 new_domain_record.postmaster_result,
1064 new_domain_record.random_result);
1068 /* If a definite result was obtained for the callout, cache it unless caching
1073 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1075 if (dbm_file == NULL)
1076 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1077 if (dbm_file == NULL)
1079 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1083 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1084 (int)sizeof(dbdata_callout_cache_address));
1085 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1086 (new_address_record.result == ccache_accept)? "positive" : "negative");
1091 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1092 temporary error. If there was only one host, and a response was received, leave
1093 it alone if supplying details. Otherwise, give a generic response. */
1097 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1098 is_recipient? "recipient" : "sender");
1101 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1103 addr->user_message = (!smtp_return_error_details)? dullmsg :
1104 string_sprintf("%s for <%s>.\n"
1105 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1106 "they may be permanently unreachable from this server. In the latter case,\n%s",
1107 dullmsg, addr->address,
1109 "the address will never be accepted."
1111 "you need to change the address or create an MX record for its domain\n"
1112 "if it is supposed to be generally accessible from the Internet.\n"
1113 "Talk to your mail administrator for details.");
1115 /* Force a specific error code */
1117 addr->basic_errno = ERRNO_CALLOUTDEFER;
1120 /* Come here from within the cache-reading code on fast-track exit. */
1123 if (dbm_file != NULL) dbfn_close(dbm_file);
1129 /* Called after recipient-acl to get a cutthrough connection open when
1130 one was requested and a recipient-verify wasn't subsequently done.
1133 open_cutthrough_connection( address_item * addr )
1137 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1138 /* We must use a copy of the address for verification, because it might
1142 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1143 (void) verify_address(&addr2, NULL,
1144 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1145 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1147 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1153 /* Send given number of bytes from the buffer */
1155 cutthrough_send(int n)
1157 if(cutthrough_fd < 0)
1162 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1164 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1167 transport_count += n;
1168 ctblock.ptr= ctblock.buffer;
1172 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1179 _cutthrough_puts(uschar * cp, int n)
1183 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1184 if(!cutthrough_send(ctblock.buffersize))
1187 *ctblock.ptr++ = *cp++;
1192 /* Buffered output of counted data block. Return boolean success */
1194 cutthrough_puts(uschar * cp, int n)
1196 if (cutthrough_fd < 0) return TRUE;
1197 if (_cutthrough_puts(cp, n)) return TRUE;
1198 cancel_cutthrough_connection("transmit failed");
1204 _cutthrough_flush_send( void )
1206 int n= ctblock.ptr-ctblock.buffer;
1209 if(!cutthrough_send(n))
1215 /* Send out any bufferred output. Return boolean success. */
1217 cutthrough_flush_send( void )
1219 if (_cutthrough_flush_send()) return TRUE;
1220 cancel_cutthrough_connection("transmit failed");
1226 cutthrough_put_nl( void )
1228 return cutthrough_puts(US"\r\n", 2);
1232 /* Get and check response from cutthrough target */
1234 cutthrough_response(char expect, uschar ** copy)
1236 smtp_inblock inblock;
1237 uschar inbuffer[4096];
1238 uschar responsebuffer[4096];
1240 inblock.buffer = inbuffer;
1241 inblock.buffersize = sizeof(inbuffer);
1242 inblock.ptr = inbuffer;
1243 inblock.ptrend = inbuffer;
1244 inblock.sock = cutthrough_fd;
1245 /* this relies on (inblock.sock == tls_out.active) */
1246 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1247 cancel_cutthrough_connection("target timeout on read");
1252 *copy= cp= string_copy(responsebuffer);
1253 /* Trim the trailing end of line */
1254 cp += Ustrlen(responsebuffer);
1255 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1256 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1259 return responsebuffer[0];
1263 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1265 cutthrough_predata( void )
1267 if(cutthrough_fd < 0)
1270 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1271 cutthrough_puts(US"DATA\r\n", 6);
1272 cutthrough_flush_send();
1274 /* Assume nothing buffered. If it was it gets ignored. */
1275 return cutthrough_response('3', NULL) == '3';
1279 /* fd and use_crlf args only to match write_chunk() */
1281 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1284 while(s && (s2 = Ustrchr(s, '\n')))
1286 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1294 /* Buffered send of headers. Return success boolean. */
1295 /* Expands newlines to wire format (CR,NL). */
1296 /* Also sends header-terminating blank line. */
1298 cutthrough_headers_send( void )
1300 if(cutthrough_fd < 0)
1303 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1304 but having a separate buffered-output function (for now)
1306 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1308 if (!transport_headers_send(&cutthrough_addr, cutthrough_fd,
1309 cutthrough_addr.transport->add_headers, cutthrough_addr.transport->remove_headers,
1310 &cutthrough_write_chunk, TRUE,
1311 cutthrough_addr.transport->rewrite_rules, cutthrough_addr.transport->rewrite_existflags))
1314 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1320 close_cutthrough_connection( const char * why )
1322 if(cutthrough_fd >= 0)
1324 /* We could be sending this after a bunch of data, but that is ok as
1325 the only way to cancel the transfer in dataphase is to drop the tcp
1326 conn before the final dot.
1328 ctblock.ptr = ctbuffer;
1329 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1330 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1331 _cutthrough_flush_send();
1332 /* No wait for response */
1335 tls_close(FALSE, TRUE);
1337 (void)close(cutthrough_fd);
1339 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1341 ctblock.ptr = ctbuffer;
1345 cancel_cutthrough_connection( const char * why )
1347 close_cutthrough_connection(why);
1348 cutthrough_delivery= FALSE;
1354 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1355 Log an OK response as a transmission.
1356 Close the connection.
1357 Return smtp response-class digit.
1360 cutthrough_finaldot( void )
1362 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1364 /* Assume data finshed with new-line */
1365 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1366 return cutthrough_addr.message;
1368 switch(cutthrough_response('2', &cutthrough_addr.message))
1371 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1372 close_cutthrough_connection("delivered");
1376 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1380 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1386 return cutthrough_addr.message;
1391 /*************************************************
1392 * Copy error to toplevel address *
1393 *************************************************/
1395 /* This function is used when a verify fails or defers, to ensure that the
1396 failure or defer information is in the original toplevel address. This applies
1397 when an address is redirected to a single new address, and the failure or
1398 deferral happens to the child address.
1401 vaddr the verify address item
1402 addr the final address item
1405 Returns: the value of YIELD
1409 copy_error(address_item *vaddr, address_item *addr, int yield)
1413 vaddr->message = addr->message;
1414 vaddr->user_message = addr->user_message;
1415 vaddr->basic_errno = addr->basic_errno;
1416 vaddr->more_errno = addr->more_errno;
1417 vaddr->p.address_data = addr->p.address_data;
1418 copyflag(vaddr, addr, af_pass_message);
1426 /**************************************************
1427 * printf that automatically handles TLS if needed *
1428 ***************************************************/
1430 /* This function is used by verify_address() as a substitute for all fprintf()
1431 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1432 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1433 that assumes that we always use the smtp_out FILE* when not using TLS or the
1434 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1435 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1439 f the candidate FILE* to write to
1440 format format string
1441 ... optional arguments
1447 static void PRINTF_FUNCTION(2,3)
1448 respond_printf(FILE *f, const char *format, ...)
1452 va_start(ap, format);
1453 if (smtp_out && (f == smtp_out))
1454 smtp_vprintf(format, ap);
1456 vfprintf(f, format, ap);
1462 /*************************************************
1463 * Verify an email address *
1464 *************************************************/
1466 /* This function is used both for verification (-bv and at other times) and
1467 address testing (-bt), which is indicated by address_test_mode being set.
1470 vaddr contains the address to verify; the next field in this block
1472 f if not NULL, write the result to this file
1473 options various option bits:
1474 vopt_fake_sender => this sender verify is not for the real
1475 sender (it was verify=sender=xxxx or an address from a
1476 header line) - rewriting must not change sender_address
1477 vopt_is_recipient => this is a recipient address, otherwise
1478 it's a sender address - this affects qualification and
1479 rewriting and messages from callouts
1480 vopt_qualify => qualify an unqualified address; else error
1481 vopt_expn => called from SMTP EXPN command
1482 vopt_success_on_redirect => when a new address is generated
1483 the verification instantly succeeds
1485 These ones are used by do_callout() -- the options variable
1488 vopt_callout_fullpm => if postmaster check, do full one
1489 vopt_callout_no_cache => don't use callout cache
1490 vopt_callout_random => do the "random" thing
1491 vopt_callout_recipsender => use real sender for recipient
1492 vopt_callout_recippmaster => use postmaster for recipient
1494 callout if > 0, specifies that callout is required, and gives timeout
1495 for individual commands
1496 callout_overall if > 0, gives overall timeout for the callout function;
1497 if < 0, a default is used (see do_callout())
1498 callout_connect the connection timeout for callouts
1499 se_mailfrom when callout is requested to verify a sender, use this
1500 in MAIL FROM; NULL => ""
1501 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1502 thing and use this as the sender address (may be "")
1504 routed if not NULL, set TRUE if routing succeeded, so we can
1505 distinguish between routing failed and callout failed
1507 Returns: OK address verified
1508 FAIL address failed to verify
1509 DEFER can't tell at present
1513 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1514 int callout_overall, int callout_connect, uschar *se_mailfrom,
1515 uschar *pm_mailfrom, BOOL *routed)
1518 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1519 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1520 BOOL expn = (options & vopt_expn) != 0;
1521 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1524 int verify_type = expn? v_expn :
1525 address_test_mode? v_none :
1526 is_recipient? v_recipient : v_sender;
1527 address_item *addr_list;
1528 address_item *addr_new = NULL;
1529 address_item *addr_remote = NULL;
1530 address_item *addr_local = NULL;
1531 address_item *addr_succeed = NULL;
1532 uschar **failure_ptr = is_recipient?
1533 &recipient_verify_failure : &sender_verify_failure;
1534 uschar *ko_prefix, *cr;
1535 uschar *address = vaddr->address;
1536 uschar *save_sender;
1537 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1539 /* Clear, just in case */
1541 *failure_ptr = NULL;
1543 /* Set up a prefix and suffix for error message which allow us to use the same
1544 output statements both in EXPN mode (where an SMTP response is needed) and when
1545 debugging with an output file. */
1549 ko_prefix = US"553 ";
1552 else ko_prefix = cr = US"";
1554 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1556 if (parse_find_at(address) == NULL)
1558 if ((options & vopt_qualify) == 0)
1561 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1562 ko_prefix, address, cr);
1563 *failure_ptr = US"qualify";
1566 address = rewrite_address_qualify(address, is_recipient);
1571 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1572 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1575 /* Rewrite and report on it. Clear the domain and local part caches - these
1576 may have been set by domains and local part tests during an ACL. */
1578 if (global_rewrite_rules != NULL)
1580 uschar *old = address;
1581 address = rewrite_address(address, is_recipient, FALSE,
1582 global_rewrite_rules, rewrite_existflags);
1585 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1586 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1587 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1591 /* If this is the real sender address, we must update sender_address at
1592 this point, because it may be referred to in the routers. */
1594 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1595 sender_address = address;
1597 /* If the address was rewritten to <> no verification can be done, and we have
1598 to return OK. This rewriting is permitted only for sender addresses; for other
1599 addresses, such rewriting fails. */
1601 if (address[0] == 0) return OK;
1603 /* Flip the legacy TLS-related variables over to the outbound set in case
1604 they're used in the context of a transport used by verification. Reset them
1605 at exit from this routine. */
1607 tls_modify_variables(&tls_out);
1609 /* Save a copy of the sender address for re-instating if we change it to <>
1610 while verifying a sender address (a nice bit of self-reference there). */
1612 save_sender = sender_address;
1614 /* Update the address structure with the possibly qualified and rewritten
1615 address. Set it up as the starting address on the chain of new addresses. */
1617 vaddr->address = address;
1620 /* We need a loop, because an address can generate new addresses. We must also
1621 cope with generated pipes and files at the top level. (See also the code and
1622 comment in deliver.c.) However, it is usually the case that the router for
1623 user's .forward files has its verify flag turned off.
1625 If an address generates more than one child, the loop is used only when
1626 full_info is set, and this can only be set locally. Remote enquiries just get
1627 information about the top level address, not anything that it generated. */
1629 while (addr_new != NULL)
1632 address_item *addr = addr_new;
1634 addr_new = addr->next;
1639 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1640 debug_printf("Considering %s\n", addr->address);
1643 /* Handle generated pipe, file or reply addresses. We don't get these
1644 when handling EXPN, as it does only one level of expansion. */
1646 if (testflag(addr, af_pfr))
1653 if (addr->address[0] == '>')
1655 allow = testflag(addr, af_allow_reply);
1656 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1660 allow = (addr->address[0] == '|')?
1661 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1662 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1665 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1666 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1667 "%s\n", addr->message);
1669 fprintf(f, "\n transport = %s\n", addr->transport->name);
1671 fprintf(f, " *** forbidden ***\n");
1676 /* Just in case some router parameter refers to it. */
1678 return_path = (addr->p.errors_address != NULL)?
1679 addr->p.errors_address : sender_address;
1681 /* Split the address into domain and local part, handling the %-hack if
1682 necessary, and then route it. While routing a sender address, set
1683 $sender_address to <> because that is what it will be if we were trying to
1684 send a bounce to the sender. */
1686 if (routed != NULL) *routed = FALSE;
1687 if ((rc = deliver_split_address(addr)) == OK)
1689 if (!is_recipient) sender_address = null_sender;
1690 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1691 &addr_succeed, verify_type);
1692 sender_address = save_sender; /* Put back the real sender */
1695 /* If routing an address succeeded, set the flag that remembers, for use when
1696 an ACL cached a sender verify (in case a callout fails). Then if routing set
1697 up a list of hosts or the transport has a host list, and the callout option
1698 is set, and we aren't in a host checking run, do the callout verification,
1699 and set another flag that notes that a callout happened. */
1703 if (routed != NULL) *routed = TRUE;
1706 host_item *host_list = addr->host_list;
1708 /* Make up some data for use in the case where there is no remote
1711 transport_feedback tf = {
1712 NULL, /* interface (=> any) */
1713 US"smtp", /* port */
1714 US"smtp", /* protocol */
1716 US"$smtp_active_hostname", /* helo_data */
1717 FALSE, /* hosts_override */
1718 FALSE, /* hosts_randomize */
1719 FALSE, /* gethostbyname */
1720 TRUE, /* qualify_single */
1721 FALSE /* search_parents */
1724 /* If verification yielded a remote transport, we want to use that
1725 transport's options, so as to mimic what would happen if we were really
1726 sending a message to this address. */
1728 if (addr->transport != NULL && !addr->transport->info->local)
1730 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1732 /* If the transport has hosts and the router does not, or if the
1733 transport is configured to override the router's hosts, we must build a
1734 host list of the transport's hosts, and find the IP addresses */
1736 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1739 uschar *save_deliver_domain = deliver_domain;
1740 uschar *save_deliver_localpart = deliver_localpart;
1742 host_list = NULL; /* Ignore the router's hosts */
1744 deliver_domain = addr->domain;
1745 deliver_localpart = addr->local_part;
1746 s = expand_string(tf.hosts);
1747 deliver_domain = save_deliver_domain;
1748 deliver_localpart = save_deliver_localpart;
1752 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1753 "\"%s\" in %s transport for callout: %s", tf.hosts,
1754 addr->transport->name, expand_string_message);
1759 uschar *canonical_name;
1760 host_item *host, *nexthost;
1761 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1763 /* Just ignore failures to find a host address. If we don't manage
1764 to find any addresses, the callout will defer. Note that more than
1765 one address may be found for a single host, which will result in
1766 additional host items being inserted into the chain. Hence we must
1767 save the next host first. */
1769 flags = HOST_FIND_BY_A;
1770 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1771 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1773 for (host = host_list; host != NULL; host = nexthost)
1775 nexthost = host->next;
1776 if (tf.gethostbyname ||
1777 string_is_ip_address(host->name, NULL) != 0)
1778 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1781 uschar * d_request = NULL, * d_require = NULL;
1782 if (Ustrcmp(addr->transport->driver_name, "smtp") == 0)
1784 smtp_transport_options_block * ob =
1785 (smtp_transport_options_block *)
1786 addr->transport->options_block;
1787 d_request = ob->dnssec_request_domains;
1788 d_require = ob->dnssec_require_domains;
1791 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1792 d_request, d_require, &canonical_name, NULL);
1799 /* Can only do a callout if we have at least one host! If the callout
1800 fails, it will have set ${sender,recipient}_verify_failure. */
1802 if (host_list != NULL)
1804 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1805 if (host_checking && !host_checking_callout)
1808 debug_printf("... callout omitted by default when host testing\n"
1809 "(Use -bhc if you want the callouts to happen.)\n");
1814 deliver_set_expansions(addr);
1816 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1817 callout_connect, options, se_mailfrom, pm_mailfrom);
1822 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1823 "transport provided a host list\n");
1828 /* Otherwise, any failure is a routing failure */
1830 else *failure_ptr = US"route";
1832 /* A router may return REROUTED if it has set up a child address as a result
1833 of a change of domain name (typically from widening). In this case we always
1834 want to continue to verify the new child. */
1836 if (rc == REROUTED) continue;
1838 /* Handle hard failures */
1845 address_item *p = addr->parent;
1847 respond_printf(f, "%s%s %s", ko_prefix,
1848 full_info? addr->address : address,
1849 address_test_mode? "is undeliverable" : "failed to verify");
1850 if (!expn && admin_user)
1852 if (addr->basic_errno > 0)
1853 respond_printf(f, ": %s", strerror(addr->basic_errno));
1854 if (addr->message != NULL)
1855 respond_printf(f, ": %s", addr->message);
1858 /* Show parents iff doing full info */
1860 if (full_info) while (p != NULL)
1862 respond_printf(f, "%s\n <-- %s", cr, p->address);
1865 respond_printf(f, "%s\n", cr);
1867 cancel_cutthrough_connection("routing hard fail");
1871 yield = copy_error(vaddr, addr, FAIL);
1879 else if (rc == DEFER)
1884 address_item *p = addr->parent;
1885 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1886 full_info? addr->address : address);
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);
1893 else if (addr->basic_errno <= 0)
1894 respond_printf(f, ": unknown error");
1897 /* Show parents iff doing full info */
1899 if (full_info) while (p != NULL)
1901 respond_printf(f, "%s\n <-- %s", cr, p->address);
1904 respond_printf(f, "%s\n", cr);
1906 cancel_cutthrough_connection("routing soft fail");
1910 yield = copy_error(vaddr, addr, DEFER);
1913 else if (yield == OK) yield = DEFER;
1916 /* If we are handling EXPN, we do not want to continue to route beyond
1917 the top level (whose address is in "address"). */
1921 uschar *ok_prefix = US"250-";
1922 if (addr_new == NULL)
1924 if (addr_local == NULL && addr_remote == NULL)
1925 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1927 respond_printf(f, "250 <%s>\r\n", address);
1929 else while (addr_new != NULL)
1931 address_item *addr2 = addr_new;
1932 addr_new = addr2->next;
1933 if (addr_new == NULL) ok_prefix = US"250 ";
1934 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1940 /* Successful routing other than EXPN. */
1944 /* Handle successful routing when short info wanted. Otherwise continue for
1945 other (generated) addresses. Short info is the operational case. Full info
1946 can be requested only when debug_selector != 0 and a file is supplied.
1948 There is a conflict between the use of aliasing as an alternate email
1949 address, and as a sort of mailing list. If an alias turns the incoming
1950 address into just one address (e.g. J.Caesar->jc44) you may well want to
1951 carry on verifying the generated address to ensure it is valid when
1952 checking incoming mail. If aliasing generates multiple addresses, you
1953 probably don't want to do this. Exim therefore treats the generation of
1954 just a single new address as a special case, and continues on to verify the
1955 generated address. */
1957 if (!full_info && /* Stop if short info wanted AND */
1958 (((addr_new == NULL || /* No new address OR */
1959 addr_new->next != NULL || /* More than one new address OR */
1960 testflag(addr_new, af_pfr))) /* New address is pfr */
1962 (addr_new != NULL && /* At least one new address AND */
1963 success_on_redirect))) /* success_on_redirect is set */
1965 if (f != NULL) fprintf(f, "%s %s\n", address,
1966 address_test_mode? "is deliverable" : "verified");
1968 /* If we have carried on to verify a child address, we want the value
1969 of $address_data to be that of the child */
1971 vaddr->p.address_data = addr->p.address_data;
1976 } /* Loop for generated addresses */
1978 /* Display the full results of the successful routing, including any generated
1979 addresses. Control gets here only when full_info is set, which requires f not
1980 to be NULL, and this occurs only when a top-level verify is called with the
1981 debugging switch on.
1983 If there are no local and no remote addresses, and there were no pipes, files,
1984 or autoreplies, and there were no errors or deferments, the message is to be
1985 discarded, usually because of the use of :blackhole: in an alias file. */
1987 if (allok && addr_local == NULL && addr_remote == NULL)
1989 fprintf(f, "mail to %s is discarded\n", address);
1993 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1995 while (addr_list != NULL)
1997 address_item *addr = addr_list;
1998 address_item *p = addr->parent;
1999 addr_list = addr->next;
2001 fprintf(f, "%s", CS addr->address);
2002 #ifdef EXPERIMENTAL_SRS
2003 if(addr->p.srs_sender)
2004 fprintf(f, " [srs = %s]", addr->p.srs_sender);
2007 /* If the address is a duplicate, show something about it. */
2009 if (!testflag(addr, af_pfr))
2012 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
2013 fprintf(f, " [duplicate, would not be delivered]");
2014 else tree_add_duplicate(addr->unique, addr);
2017 /* Now show its parents */
2021 fprintf(f, "\n <-- %s", p->address);
2026 /* Show router, and transport */
2028 fprintf(f, "router = %s, ", addr->router->name);
2029 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
2030 addr->transport->name);
2032 /* Show any hosts that are set up by a router unless the transport
2033 is going to override them; fiddle a bit to get a nice format. */
2035 if (addr->host_list != NULL && addr->transport != NULL &&
2036 !addr->transport->overrides_hosts)
2041 for (h = addr->host_list; h != NULL; h = h->next)
2043 int len = Ustrlen(h->name);
2044 if (len > maxlen) maxlen = len;
2045 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2046 if (len > maxaddlen) maxaddlen = len;
2048 for (h = addr->host_list; h != NULL; h = h->next)
2050 int len = Ustrlen(h->name);
2051 fprintf(f, " host %s ", h->name);
2052 while (len++ < maxlen) fprintf(f, " ");
2053 if (h->address != NULL)
2055 fprintf(f, "[%s] ", h->address);
2056 len = Ustrlen(h->address);
2058 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2060 fprintf(f, "[unknown] ");
2064 while (len++ < maxaddlen) fprintf(f," ");
2065 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2066 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2067 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2074 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2075 the -bv or -bt case). */
2078 tls_modify_variables(&tls_in);
2086 /*************************************************
2087 * Check headers for syntax errors *
2088 *************************************************/
2090 /* This function checks those header lines that contain addresses, and verifies
2091 that all the addresses therein are syntactially correct.
2094 msgptr where to put an error message
2101 verify_check_headers(uschar **msgptr)
2107 for (h = header_list; h != NULL && yield == OK; h = h->next)
2109 if (h->type != htype_from &&
2110 h->type != htype_reply_to &&
2111 h->type != htype_sender &&
2112 h->type != htype_to &&
2113 h->type != htype_cc &&
2114 h->type != htype_bcc)
2117 colon = Ustrchr(h->text, ':');
2119 while (isspace(*s)) s++;
2121 /* Loop for multiple addresses in the header, enabling group syntax. Note
2122 that we have to reset this after the header has been scanned. */
2124 parse_allow_group = TRUE;
2128 uschar *ss = parse_find_address_end(s, FALSE);
2129 uschar *recipient, *errmess;
2130 int terminator = *ss;
2131 int start, end, domain;
2133 /* Temporarily terminate the string at this point, and extract the
2134 operative address within, allowing group syntax. */
2137 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2140 /* Permit an unqualified address only if the message is local, or if the
2141 sending host is configured to be permitted to send them. */
2143 if (recipient != NULL && domain == 0)
2145 if (h->type == htype_from || h->type == htype_sender)
2147 if (!allow_unqualified_sender) recipient = NULL;
2151 if (!allow_unqualified_recipient) recipient = NULL;
2153 if (recipient == NULL) errmess = US"unqualified address not permitted";
2156 /* It's an error if no address could be extracted, except for the special
2157 case of an empty address. */
2159 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2161 uschar *verb = US"is";
2166 /* Arrange not to include any white space at the end in the
2167 error message or the header name. */
2169 while (t > s && isspace(t[-1])) t--;
2170 while (tt > h->text && isspace(tt[-1])) tt--;
2172 /* Add the address that failed to the error message, since in a
2173 header with very many addresses it is sometimes hard to spot
2174 which one is at fault. However, limit the amount of address to
2175 quote - cases have been seen where, for example, a missing double
2176 quote in a humungous To: header creates an "address" that is longer
2177 than string_sprintf can handle. */
2186 *msgptr = string_printing(
2187 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2188 errmess, tt - h->text, h->text, verb, len, s));
2191 break; /* Out of address loop */
2194 /* Advance to the next address */
2196 s = ss + (terminator? 1:0);
2197 while (isspace(*s)) s++;
2198 } /* Next address */
2200 parse_allow_group = FALSE;
2201 parse_found_group = FALSE;
2202 } /* Next header unless yield has been set FALSE */
2208 /*************************************************
2209 * Check header names for 8-bit characters *
2210 *************************************************/
2212 /* This function checks for invalid charcters in header names. See
2213 RFC 5322, 2.2. and RFC 6532, 3.
2216 msgptr where to put an error message
2223 verify_check_header_names_ascii(uschar **msgptr)
2228 for (h = header_list; h != NULL; h = h->next)
2230 colon = Ustrchr(h->text, ':');
2231 for(s = h->text; s < colon; s++)
2233 if ((*s < 33) || (*s > 126))
2235 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2236 colon - h->text, h->text);
2244 /*************************************************
2245 * Check for blind recipients *
2246 *************************************************/
2248 /* This function checks that every (envelope) recipient is mentioned in either
2249 the To: or Cc: header lines, thus detecting blind carbon copies.
2251 There are two ways of scanning that could be used: either scan the header lines
2252 and tick off the recipients, or scan the recipients and check the header lines.
2253 The original proposed patch did the former, but I have chosen to do the latter,
2254 because (a) it requires no memory and (b) will use fewer resources when there
2255 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2258 Returns: OK if there are no blind recipients
2259 FAIL if there is at least one blind recipient
2263 verify_check_notblind(void)
2266 for (i = 0; i < recipients_count; i++)
2270 uschar *address = recipients_list[i].address;
2272 for (h = header_list; !found && h != NULL; h = h->next)
2276 if (h->type != htype_to && h->type != htype_cc) continue;
2278 colon = Ustrchr(h->text, ':');
2280 while (isspace(*s)) s++;
2282 /* Loop for multiple addresses in the header, enabling group syntax. Note
2283 that we have to reset this after the header has been scanned. */
2285 parse_allow_group = TRUE;
2289 uschar *ss = parse_find_address_end(s, FALSE);
2290 uschar *recipient,*errmess;
2291 int terminator = *ss;
2292 int start, end, domain;
2294 /* Temporarily terminate the string at this point, and extract the
2295 operative address within, allowing group syntax. */
2298 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2301 /* If we found a valid recipient that has a domain, compare it with the
2302 envelope recipient. Local parts are compared case-sensitively, domains
2303 case-insensitively. By comparing from the start with length "domain", we
2304 include the "@" at the end, which ensures that we are comparing the whole
2305 local part of each address. */
2307 if (recipient != NULL && domain != 0)
2309 found = Ustrncmp(recipient, address, domain) == 0 &&
2310 strcmpic(recipient + domain, address + domain) == 0;
2314 /* Advance to the next address */
2316 s = ss + (terminator? 1:0);
2317 while (isspace(*s)) s++;
2318 } /* Next address */
2320 parse_allow_group = FALSE;
2321 parse_found_group = FALSE;
2322 } /* Next header (if found is false) */
2324 if (!found) return FAIL;
2325 } /* Next recipient */
2332 /*************************************************
2333 * Find if verified sender *
2334 *************************************************/
2336 /* Usually, just a single address is verified as the sender of the message.
2337 However, Exim can be made to verify other addresses as well (often related in
2338 some way), and this is useful in some environments. There may therefore be a
2339 chain of such addresses that have previously been tested. This function finds
2340 whether a given address is on the chain.
2342 Arguments: the address to be verified
2343 Returns: pointer to an address item, or NULL
2347 verify_checked_sender(uschar *sender)
2350 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2351 if (Ustrcmp(sender, addr->address) == 0) break;
2359 /*************************************************
2360 * Get valid header address *
2361 *************************************************/
2363 /* Scan the originator headers of the message, looking for an address that
2364 verifies successfully. RFC 822 says:
2366 o The "Sender" field mailbox should be sent notices of
2367 any problems in transport or delivery of the original
2368 messages. If there is no "Sender" field, then the
2369 "From" field mailbox should be used.
2371 o If the "Reply-To" field exists, then the reply should
2372 go to the addresses indicated in that field and not to
2373 the address(es) indicated in the "From" field.
2375 So we check a Sender field if there is one, else a Reply_to field, else a From
2376 field. As some strange messages may have more than one of these fields,
2377 especially if they are resent- fields, check all of them if there is more than
2381 user_msgptr points to where to put a user error message
2382 log_msgptr points to where to put a log error message
2383 callout timeout for callout check (passed to verify_address())
2384 callout_overall overall callout timeout (ditto)
2385 callout_connect connect callout timeout (ditto)
2386 se_mailfrom mailfrom for verify; NULL => ""
2387 pm_mailfrom sender for pm callout check (passed to verify_address())
2388 options callout options (passed to verify_address())
2389 verrno where to put the address basic_errno
2391 If log_msgptr is set to something without setting user_msgptr, the caller
2392 normally uses log_msgptr for both things.
2394 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2395 FAIL is given if no appropriate headers are found
2399 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2400 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2401 uschar *pm_mailfrom, int options, int *verrno)
2403 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2408 for (i = 0; i < 3 && !done; i++)
2411 for (h = header_list; h != NULL && !done; h = h->next)
2413 int terminator, new_ok;
2414 uschar *s, *ss, *endname;
2416 if (h->type != header_types[i]) continue;
2417 s = endname = Ustrchr(h->text, ':') + 1;
2419 /* Scan the addresses in the header, enabling group syntax. Note that we
2420 have to reset this after the header has been scanned. */
2422 parse_allow_group = TRUE;
2426 address_item *vaddr;
2428 while (isspace(*s) || *s == ',') s++;
2429 if (*s == 0) break; /* End of header */
2431 ss = parse_find_address_end(s, FALSE);
2433 /* The terminator is a comma or end of header, but there may be white
2434 space preceding it (including newline for the last address). Move back
2435 past any white space so we can check against any cached envelope sender
2436 address verifications. */
2438 while (isspace(ss[-1])) ss--;
2442 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2443 (int)(endname - h->text), h->text, s);
2445 /* See if we have already verified this address as an envelope sender,
2446 and if so, use the previous answer. */
2448 vaddr = verify_checked_sender(s);
2450 if (vaddr != NULL && /* Previously checked */
2451 (callout <= 0 || /* No callout needed; OR */
2452 vaddr->special_action > 256)) /* Callout was done */
2454 new_ok = vaddr->special_action & 255;
2455 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2456 *ss = terminator; /* Restore shortened string */
2459 /* Otherwise we run the verification now. We must restore the shortened
2460 string before running the verification, so the headers are correct, in
2461 case there is any rewriting. */
2465 int start, end, domain;
2466 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2471 /* If we found an empty address, just carry on with the next one, but
2472 kill the message. */
2474 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2481 /* If verification failed because of a syntax error, fail this
2482 function, and ensure that the failing address gets added to the error
2485 if (address == NULL)
2488 while (ss > s && isspace(ss[-1])) ss--;
2489 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2490 "scanning for sender: %s in \"%.*s\"",
2491 endname - h->text, h->text, *log_msgptr, ss - s, s);
2497 /* Else go ahead with the sender verification. But it isn't *the*
2498 sender of the message, so set vopt_fake_sender to stop sender_address
2499 being replaced after rewriting or qualification. */
2503 vaddr = deliver_make_addr(address, FALSE);
2504 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2505 callout, callout_overall, callout_connect, se_mailfrom,
2510 /* We now have the result, either newly found, or cached. If we are
2511 giving out error details, set a specific user error. This means that the
2512 last of these will be returned to the user if all three fail. We do not
2513 set a log message - the generic one below will be used. */
2517 *verrno = vaddr->basic_errno;
2518 if (smtp_return_error_details)
2520 *user_msgptr = string_sprintf("Rejected after DATA: "
2521 "could not verify \"%.*s\" header address\n%s: %s",
2522 endname - h->text, h->text, vaddr->address, vaddr->message);
2526 /* Success or defer */
2535 if (new_ok == DEFER) yield = DEFER;
2537 /* Move on to any more addresses in the header */
2540 } /* Next address */
2542 parse_allow_group = FALSE;
2543 parse_found_group = FALSE;
2544 } /* Next header, unless done */
2545 } /* Next header type unless done */
2547 if (yield == FAIL && *log_msgptr == NULL)
2548 *log_msgptr = US"there is no valid sender in any header line";
2550 if (yield == DEFER && *log_msgptr == NULL)
2551 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2559 /*************************************************
2560 * Get RFC 1413 identification *
2561 *************************************************/
2563 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2564 the timeout is set to zero, then the query is not done. There may also be lists
2565 of hosts and nets which are exempt. To guard against malefactors sending
2566 non-printing characters which could, for example, disrupt a message's headers,
2567 make sure the string consists of printing characters only.
2570 port the port to connect to; usually this is IDENT_PORT (113), but when
2571 running in the test harness with -bh a different value is used.
2575 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2579 verify_get_ident(int port)
2581 int sock, host_af, qlen;
2582 int received_sender_port, received_interface_port, n;
2584 uschar buffer[2048];
2586 /* Default is no ident. Check whether we want to do an ident check for this
2589 sender_ident = NULL;
2590 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2593 DEBUG(D_ident) debug_printf("doing ident callback\n");
2595 /* Set up a connection to the ident port of the remote host. Bind the local end
2596 to the incoming interface address. If the sender host address is an IPv6
2597 address, the incoming interface address will also be IPv6. */
2599 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2600 sock = ip_socket(SOCK_STREAM, host_af);
2601 if (sock < 0) return;
2603 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2605 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2610 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2613 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2615 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2616 sender_host_address);
2620 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2621 sender_host_address, strerror(errno));
2626 /* Construct and send the query. */
2628 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2629 qlen = Ustrlen(buffer);
2630 if (send(sock, buffer, qlen, 0) < 0)
2632 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2636 /* Read a response line. We put it into the rest of the buffer, using several
2637 recv() calls if necessary. */
2645 int size = sizeof(buffer) - (p - buffer);
2647 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2648 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2649 if (count <= 0) goto END_OFF; /* Read error or EOF */
2651 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2652 generous, and accept a plain \n terminator as well. The only illegal
2655 for (pp = p; pp < p + count; pp++)
2657 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2660 if (pp[-1] == '\r') pp--;
2662 goto GOT_DATA; /* Break out of both loops */
2666 /* Reached the end of the data without finding \n. Let the loop continue to
2667 read some more, if there is room. */
2674 /* We have received a line of data. Check it carefully. It must start with the
2675 same two port numbers that we sent, followed by data as defined by the RFC. For
2678 12345 , 25 : USERID : UNIX :root
2680 However, the amount of white space may be different to what we sent. In the
2681 "osname" field there may be several sub-fields, comma separated. The data we
2682 actually want to save follows the third colon. Some systems put leading spaces
2683 in it - we discard those. */
2685 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2686 &received_interface_port, &n) != 2 ||
2687 received_sender_port != sender_host_port ||
2688 received_interface_port != interface_port)
2691 p = buffer + qlen + n;
2692 while(isspace(*p)) p++;
2693 if (*p++ != ':') goto END_OFF;
2694 while(isspace(*p)) p++;
2695 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2697 while(isspace(*p)) p++;
2698 if (*p++ != ':') goto END_OFF;
2699 while (*p != 0 && *p != ':') p++;
2700 if (*p++ == 0) goto END_OFF;
2701 while(isspace(*p)) p++;
2702 if (*p == 0) goto END_OFF;
2704 /* The rest of the line is the data we want. We turn it into printing
2705 characters when we save it, so that it cannot mess up the format of any logging
2706 or Received: lines into which it gets inserted. We keep a maximum of 127
2709 sender_ident = string_printing(string_copyn(p, 127));
2710 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2720 /*************************************************
2721 * Match host to a single host-list item *
2722 *************************************************/
2724 /* This function compares a host (name or address) against a single item
2725 from a host list. The host name gets looked up if it is needed and is not
2726 already known. The function is called from verify_check_this_host() via
2727 match_check_list(), which is why most of its arguments are in a single block.
2730 arg the argument block (see below)
2731 ss the host-list item
2732 valueptr where to pass back looked up data, or NULL
2733 error for error message when returning ERROR
2736 host_name (a) the host name, or
2737 (b) NULL, implying use sender_host_name and
2738 sender_host_aliases, looking them up if required, or
2739 (c) the empty string, meaning that only IP address matches
2741 host_address the host address
2742 host_ipv4 the IPv4 address taken from an IPv6 one
2746 DEFER lookup deferred
2747 ERROR (a) failed to find the host name or IP address, or
2748 (b) unknown lookup type specified, or
2749 (c) host name encountered when only IP addresses are
2754 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2756 check_host_block *cb = (check_host_block *)arg;
2759 BOOL iplookup = FALSE;
2760 BOOL isquery = FALSE;
2761 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2766 /* Optimize for the special case when the pattern is "*". */
2768 if (*ss == '*' && ss[1] == 0) return OK;
2770 /* If the pattern is empty, it matches only in the case when there is no host -
2771 this can occur in ACL checking for SMTP input using the -bs option. In this
2772 situation, the host address is the empty string. */
2774 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2775 if (*ss == 0) return FAIL;
2777 /* If the pattern is precisely "@" then match against the primary host name,
2778 provided that host name matching is permitted; if it's "@[]" match against the
2779 local host's IP addresses. */
2785 if (isiponly) return ERROR;
2786 ss = primary_hostname;
2788 else if (Ustrcmp(ss, "@[]") == 0)
2790 ip_address_item *ip;
2791 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2792 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2797 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2798 a (possibly masked) comparision with the current IP address. */
2800 if (string_is_ip_address(ss, &maskoffset) != 0)
2801 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2803 /* The pattern is not an IP address. A common error that people make is to omit
2804 one component of an IPv4 address, either by accident, or believing that, for
2805 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,
2806 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2807 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2808 ancient specification.) To aid in debugging these cases, we give a specific
2809 error if the pattern contains only digits and dots or contains a slash preceded
2810 only by digits and dots (a slash at the start indicates a file name and of
2811 course slashes may be present in lookups, but not preceded only by digits and
2814 for (t = ss; isdigit(*t) || *t == '.'; t++);
2815 if (*t == 0 || (*t == '/' && t != ss))
2817 *error = US"malformed IPv4 address or address mask";
2821 /* See if there is a semicolon in the pattern */
2823 semicolon = Ustrchr(ss, ';');
2825 /* If we are doing an IP address only match, then all lookups must be IP
2826 address lookups, even if there is no "net-". */
2830 iplookup = semicolon != NULL;
2833 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2834 a lookup on a masked IP network, in textual form. We obey this code even if we
2835 have already set iplookup, so as to skip over the "net-" prefix and to set the
2836 mask length. The net- stuff really only applies to single-key lookups where the
2837 key is implicit. For query-style lookups the key is specified in the query.
2838 From release 4.30, the use of net- for query style is no longer needed, but we
2839 retain it for backward compatibility. */
2841 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2844 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2845 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2846 iplookup = (*t++ == '-');
2850 /* Do the IP address lookup if that is indeed what we have */
2858 uschar *filename, *key, *result;
2861 /* Find the search type */
2863 search_type = search_findtype(t, semicolon - t);
2865 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2866 search_error_message);
2868 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2869 is no file name, and the "key" is just the query. For query-style with a file
2870 name, we have to fish the file off the start of the query. For a single-key
2871 lookup, the key is the current IP address, masked appropriately, and
2872 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2873 dot separators instead of colons, except when the lookup type is "iplsearch".
2876 if (mac_islookup(search_type, lookup_absfilequery))
2878 filename = semicolon + 1;
2880 while (*key != 0 && !isspace(*key)) key++;
2881 filename = string_copyn(filename, key - filename);
2882 while (isspace(*key)) key++;
2884 else if (mac_islookup(search_type, lookup_querystyle))
2887 key = semicolon + 1;
2889 else /* Single-key style */
2891 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2893 insize = host_aton(cb->host_address, incoming);
2894 host_mask(insize, incoming, mlen);
2895 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2897 filename = semicolon + 1;
2900 /* Now do the actual lookup; note that there is no search_close() because
2901 of the caching arrangements. */
2903 handle = search_open(filename, search_type, 0, NULL, NULL);
2904 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2905 search_error_message);
2906 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2907 if (valueptr != NULL) *valueptr = result;
2908 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2911 /* The pattern is not an IP address or network reference of any kind. That is,
2912 it is a host name pattern. If this is an IP only match, there's an error in the
2917 *error = US"cannot match host name in match_ip list";
2921 /* Check the characters of the pattern to see if they comprise only letters,
2922 digits, full stops, and hyphens (the constituents of domain names). Allow
2923 underscores, as they are all too commonly found. Sigh. Also, if
2924 allow_utf8_domains is set, allow top-bit characters. */
2926 for (t = ss; *t != 0; t++)
2927 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2928 (!allow_utf8_domains || *t < 128)) break;
2930 /* If the pattern is a complete domain name, with no fancy characters, look up
2931 its IP address and match against that. Note that a multi-homed host will add
2932 items to the chain. */
2943 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2944 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2947 for (hh = &h; hh != NULL; hh = hh->next)
2949 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2953 if (rc == HOST_FIND_AGAIN) return DEFER;
2954 *error = string_sprintf("failed to find IP address for %s", ss);
2958 /* Almost all subsequent comparisons require the host name, and can be done
2959 using the general string matching function. When this function is called for
2960 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2961 must use sender_host_name and its aliases, looking them up if necessary. */
2963 if (cb->host_name != NULL) /* Explicit host name given */
2964 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2967 /* Host name not given; in principle we need the sender host name and its
2968 aliases. However, for query-style lookups, we do not need the name if the
2969 query does not contain $sender_host_name. From release 4.23, a reference to
2970 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2973 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2976 int partial, affixlen, starflags, id;
2979 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2982 if (id < 0) /* Unknown lookup type */
2984 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2985 search_error_message, ss);
2988 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2993 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2996 case DEFER: return DEFER;
2997 default: return FAIL;
3001 /* Not a query-style lookup; must ensure the host name is present, and then we
3002 do a check on the name and all its aliases. */
3004 if (sender_host_name == NULL)
3006 HDEBUG(D_host_lookup)
3007 debug_printf("sender host name required, to match against %s\n", ss);
3008 if (host_lookup_failed || host_name_lookup() != OK)
3010 *error = string_sprintf("failed to find host name for %s",
3011 sender_host_address);;
3014 host_build_sender_fullhost();
3017 /* Match on the sender host name, using the general matching function */
3019 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3023 case DEFER: return DEFER;
3026 /* If there are aliases, try matching on them. */
3028 aliases = sender_host_aliases;
3029 while (*aliases != NULL)
3031 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3034 case DEFER: return DEFER;
3043 /*************************************************
3044 * Check a specific host matches a host list *
3045 *************************************************/
3047 /* This function is passed a host list containing items in a number of
3048 different formats and the identity of a host. Its job is to determine whether
3049 the given host is in the set of hosts defined by the list. The host name is
3050 passed as a pointer so that it can be looked up if needed and not already
3051 known. This is commonly the case when called from verify_check_host() to check
3052 an incoming connection. When called from elsewhere the host name should usually
3055 This function is now just a front end to match_check_list(), which runs common
3056 code for scanning a list. We pass it the check_host() function to perform a
3060 listptr pointer to the host list
3061 cache_bits pointer to cache for named lists, or NULL
3062 host_name the host name or NULL, implying use sender_host_name and
3063 sender_host_aliases, looking them up if required
3064 host_address the IP address
3065 valueptr if not NULL, data from a lookup is passed back here
3067 Returns: OK if the host is in the defined set
3068 FAIL if the host is not in the defined set,
3069 DEFER if a data lookup deferred (not a host lookup)
3071 If the host name was needed in order to make a comparison, and could not be
3072 determined from the IP address, the result is FAIL unless the item
3073 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3076 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
3077 uschar *host_name, uschar *host_address, uschar **valueptr)
3080 unsigned int *local_cache_bits = cache_bits;
3081 uschar *save_host_address = deliver_host_address;
3082 check_host_block cb;
3083 cb.host_name = host_name;
3084 cb.host_address = host_address;
3086 if (valueptr != NULL) *valueptr = NULL;
3088 /* If the host address starts off ::ffff: it is an IPv6 address in
3089 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3092 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3093 host_address + 7 : host_address;
3095 /* During the running of the check, put the IP address into $host_address. In
3096 the case of calls from the smtp transport, it will already be there. However,
3097 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3098 the safe side, any existing setting is preserved, though as I write this
3099 (November 2004) I can't see any cases where it is actually needed. */
3101 deliver_host_address = host_address;
3102 rc = match_check_list(
3103 listptr, /* the list */
3104 0, /* separator character */
3105 &hostlist_anchor, /* anchor pointer */
3106 &local_cache_bits, /* cache pointer */
3107 check_host, /* function for testing */
3108 &cb, /* argument for function */
3109 MCL_HOST, /* type of check */
3110 (host_address == sender_host_address)?
3111 US"host" : host_address, /* text for debugging */
3112 valueptr); /* where to pass back data */
3113 deliver_host_address = save_host_address;
3120 /*************************************************
3121 * Check the remote host matches a list *
3122 *************************************************/
3124 /* This is a front end to verify_check_this_host(), created because checking
3125 the remote host is a common occurrence. With luck, a good compiler will spot
3126 the tail recursion and optimize it. If there's no host address, this is
3127 command-line SMTP input - check against an empty string for the address.
3130 listptr pointer to the host list
3132 Returns: the yield of verify_check_this_host(),
3133 i.e. OK, FAIL, or DEFER
3137 verify_check_host(uschar **listptr)
3139 return verify_check_this_host(listptr, sender_host_cache, NULL,
3140 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3147 /*************************************************
3148 * Invert an IP address *
3149 *************************************************/
3151 /* Originally just used for DNS xBL lists, now also used for the
3152 reverse_ip expansion operator.
3155 buffer where to put the answer
3156 address the address to invert
3160 invert_address(uschar *buffer, uschar *address)
3163 uschar *bptr = buffer;
3165 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3166 to the IPv4 part only. */
3168 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3170 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3173 if (host_aton(address, bin) == 1)
3177 for (i = 0; i < 4; i++)
3179 sprintf(CS bptr, "%d.", x & 255);
3180 while (*bptr) bptr++;
3185 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3186 in any DNS black lists, and the format in which they will be looked up is
3187 unknown. This is just a guess. */
3193 for (j = 3; j >= 0; j--)
3196 for (i = 0; i < 8; i++)
3198 sprintf(CS bptr, "%x.", x & 15);
3199 while (*bptr) bptr++;
3206 /* Remove trailing period -- this is needed so that both arbitrary
3207 dnsbl keydomains and inverted addresses may be combined with the
3208 same format string, "%s.%s" */
3215 /*************************************************
3216 * Perform a single dnsbl lookup *
3217 *************************************************/
3219 /* This function is called from verify_check_dnsbl() below. It is also called
3220 recursively from within itself when domain and domain_txt are different
3221 pointers, in order to get the TXT record from the alternate domain.
3224 domain the outer dnsbl domain
3225 domain_txt alternate domain to lookup TXT record on success; when the
3226 same domain is to be used, domain_txt == domain (that is,
3227 the pointers must be identical, not just the text)
3228 keydomain the current keydomain (for debug message)
3229 prepend subdomain to lookup (like keydomain, but
3230 reversed if IP address)
3231 iplist the list of matching IP addresses, or NULL for "any"
3232 bitmask true if bitmask matching is wanted
3233 match_type condition for 'succeed' result
3234 0 => Any RR in iplist (=)
3235 1 => No RR in iplist (!=)
3236 2 => All RRs in iplist (==)
3237 3 => Some RRs not in iplist (!==)
3238 the two bits are defined as MT_NOT and MT_ALL
3239 defer_return what to return for a defer
3241 Returns: OK if lookup succeeded
3246 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3247 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3253 dnsbl_cache_block *cb;
3254 int old_pool = store_pool;
3255 uschar query[256]; /* DNS domain max length */
3257 /* Construct the specific query domainname */
3259 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3261 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3262 "(ignored): %s...", query);
3266 /* Look for this query in the cache. */
3268 t = tree_search(dnsbl_cache, query);
3270 /* If not cached from a previous lookup, we must do a DNS lookup, and
3271 cache the result in permanent memory. */
3275 store_pool = POOL_PERM;
3277 /* Set up a tree entry to cache the lookup */
3279 t = store_get(sizeof(tree_node) + Ustrlen(query));
3280 Ustrcpy(t->name, query);
3281 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3282 (void)tree_insertnode(&dnsbl_cache, t);
3284 /* Do the DNS loopup . */
3286 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3287 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3288 cb->text_set = FALSE;
3292 /* If the lookup succeeded, cache the RHS address. The code allows for
3293 more than one address - this was for complete generality and the possible
3294 use of A6 records. However, A6 records have been reduced to experimental
3295 status (August 2001) and may die out. So they may never get used at all,
3296 let alone in dnsbl records. However, leave the code here, just in case.
3298 Quite apart from one A6 RR generating multiple addresses, there are DNS
3299 lists that return more than one A record, so we must handle multiple
3300 addresses generated in that way as well. */
3302 if (cb->rc == DNS_SUCCEED)
3305 dns_address **addrp = &(cb->rhs);
3306 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3308 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3310 if (rr->type == T_A)
3312 dns_address *da = dns_address_from_rr(&dnsa, rr);
3316 while (da->next != NULL) da = da->next;
3317 addrp = &(da->next);
3322 /* If we didn't find any A records, change the return code. This can
3323 happen when there is a CNAME record but there are no A records for what
3326 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3329 store_pool = old_pool;
3332 /* Previous lookup was cached */
3336 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3340 /* We now have the result of the DNS lookup, either newly done, or cached
3341 from a previous call. If the lookup succeeded, check against the address
3342 list if there is one. This may be a positive equality list (introduced by
3343 "="), a negative equality list (introduced by "!="), a positive bitmask
3344 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3346 if (cb->rc == DNS_SUCCEED)
3348 dns_address *da = NULL;
3349 uschar *addlist = cb->rhs->address;
3351 /* For A and AAAA records, there may be multiple addresses from multiple
3352 records. For A6 records (currently not expected to be used) there may be
3353 multiple addresses from a single record. */
3355 for (da = cb->rhs->next; da != NULL; da = da->next)
3356 addlist = string_sprintf("%s, %s", addlist, da->address);
3358 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3361 /* Address list check; this can be either for equality, or via a bitmask.
3362 In the latter case, all the bits must match. */
3366 for (da = cb->rhs; da != NULL; da = da->next)
3370 uschar *ptr = iplist;
3373 /* Handle exact matching */
3377 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3379 if (Ustrcmp(CS da->address, ip) == 0) break;
3383 /* Handle bitmask matching */
3390 /* At present, all known DNS blocking lists use A records, with
3391 IPv4 addresses on the RHS encoding the information they return. I
3392 wonder if this will linger on as the last vestige of IPv4 when IPv6
3393 is ubiquitous? Anyway, for now we use paranoia code to completely
3394 ignore IPv6 addresses. The default mask is 0, which always matches.
3395 We change this only for IPv4 addresses in the list. */
3397 if (host_aton(da->address, address) == 1) mask = address[0];
3399 /* Scan the returned addresses, skipping any that are IPv6 */
3401 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3403 if (host_aton(ip, address) != 1) continue;
3404 if ((address[0] & mask) == address[0]) break;
3410 (a) An IP address in an any ('=') list matched, or
3411 (b) No IP address in an all ('==') list matched
3413 then we're done searching. */
3415 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3418 /* If da == NULL, either
3420 (a) No IP address in an any ('=') list matched, or
3421 (b) An IP address in an all ('==') list didn't match
3423 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3426 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3434 res = US"was no match";
3437 res = US"was an exclude match";
3440 res = US"was an IP address that did not match";
3443 res = US"were no IP addresses that did not match";
3446 debug_printf("=> but we are not accepting this block class because\n");
3447 debug_printf("=> there %s for %s%c%s\n",
3449 ((match_type & MT_ALL) == 0)? "" : "=",
3450 bitmask? '&' : '=', iplist);
3456 /* Either there was no IP list, or the record matched, implying that the
3457 domain is on the list. We now want to find a corresponding TXT record. If an
3458 alternate domain is specified for the TXT record, call this function
3459 recursively to look that up; this has the side effect of re-checking that
3460 there is indeed an A record at the alternate domain. */
3462 if (domain_txt != domain)
3463 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3464 FALSE, match_type, defer_return);
3466 /* If there is no alternate domain, look up a TXT record in the main domain
3467 if it has not previously been cached. */
3471 cb->text_set = TRUE;
3472 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3475 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3477 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3478 if (rr->type == T_TXT) break;
3481 int len = (rr->data)[0];
3482 if (len > 511) len = 127;
3483 store_pool = POOL_PERM;
3484 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3485 store_pool = old_pool;
3490 dnslist_value = addlist;
3491 dnslist_text = cb->text;
3495 /* There was a problem with the DNS lookup */
3497 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3499 log_write(L_dnslist_defer, LOG_MAIN,
3500 "DNS list lookup defer (probably timeout) for %s: %s", query,
3501 (defer_return == OK)? US"assumed in list" :
3502 (defer_return == FAIL)? US"assumed not in list" :
3503 US"returned DEFER");
3504 return defer_return;
3507 /* No entry was found in the DNS; continue for next domain */
3511 debug_printf("DNS lookup for %s failed\n", query);
3512 debug_printf("=> that means %s is not listed at %s\n",
3522 /*************************************************
3523 * Check host against DNS black lists *
3524 *************************************************/
3526 /* This function runs checks against a list of DNS black lists, until one
3527 matches. Each item on the list can be of the form
3529 domain=ip-address/key
3531 The domain is the right-most domain that is used for the query, for example,
3532 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3533 if the DNS lookup returns a matching IP address. Several addresses may be
3534 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3536 If no key is given, what is looked up in the domain is the inverted IP address
3537 of the current client host. If a key is given, it is used to construct the
3538 domain for the lookup. For example:
3540 dsn.rfc-ignorant.org/$sender_address_domain
3542 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3543 then we check for a TXT record for an error message, and if found, save its
3544 value in $dnslist_text. We also cache everything in a tree, to optimize
3547 The TXT record is normally looked up in the same domain as the A record, but
3548 when many lists are combined in a single DNS domain, this will not be a very
3549 specific message. It is possible to specify a different domain for looking up
3550 TXT records; this is given before the main domain, comma-separated. For
3553 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3554 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3556 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3558 Note: an address for testing RBL is 192.203.178.39
3559 Note: an address for testing DUL is 192.203.178.4
3560 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3563 listptr the domain/address/data list
3565 Returns: OK successful lookup (i.e. the address is on the list), or
3566 lookup deferred after +include_unknown
3567 FAIL name not found, or no data found for the given type, or
3568 lookup deferred after +exclude_unknown (default)
3569 DEFER lookup failure, if +defer_unknown was set
3573 verify_check_dnsbl(uschar **listptr)
3576 int defer_return = FAIL;
3577 uschar *list = *listptr;
3580 uschar buffer[1024];
3581 uschar revadd[128]; /* Long enough for IPv6 address */
3583 /* Indicate that the inverted IP address is not yet set up */
3587 /* In case this is the first time the DNS resolver is being used. */
3589 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3591 /* Loop through all the domains supplied, until something matches */
3593 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3596 BOOL bitmask = FALSE;
3603 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3605 /* Deal with special values that change the behaviour on defer */
3607 if (domain[0] == '+')
3609 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3610 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3611 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3613 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3618 /* See if there's explicit data to be looked up */
3620 key = Ustrchr(domain, '/');
3621 if (key != NULL) *key++ = 0;
3623 /* See if there's a list of addresses supplied after the domain name. This is
3624 introduced by an = or a & character; if preceded by = we require all matches
3625 and if preceded by ! we invert the result. */
3627 iplist = Ustrchr(domain, '=');
3631 iplist = Ustrchr(domain, '&');
3634 if (iplist != NULL) /* Found either = or & */
3636 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3638 match_type |= MT_NOT;
3642 *iplist++ = 0; /* Terminate domain, move on */
3644 /* If we found = (bitmask == FALSE), check for == or =& */
3646 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3648 bitmask = *iplist++ == '&';
3649 match_type |= MT_ALL;
3653 /* If there is a comma in the domain, it indicates that a second domain for
3654 looking up TXT records is provided, before the main domain. Otherwise we must
3655 set domain_txt == domain. */
3657 domain_txt = domain;
3658 comma = Ustrchr(domain, ',');
3665 /* Check that what we have left is a sensible domain name. There is no reason
3666 why these domains should in fact use the same syntax as hosts and email
3667 domains, but in practice they seem to. However, there is little point in
3668 actually causing an error here, because that would no doubt hold up incoming
3669 mail. Instead, I'll just log it. */
3671 for (s = domain; *s != 0; s++)
3673 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3675 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3676 "strange characters - is this right?", domain);
3681 /* Check the alternate domain if present */
3683 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3685 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3687 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3688 "strange characters - is this right?", domain_txt);
3693 /* If there is no key string, construct the query by adding the domain name
3694 onto the inverted host address, and perform a single DNS lookup. */
3698 if (sender_host_address == NULL) return FAIL; /* can never match */
3699 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3700 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3701 iplist, bitmask, match_type, defer_return);
3704 dnslist_domain = string_copy(domain_txt);
3705 dnslist_matched = string_copy(sender_host_address);
3706 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3707 sender_host_address, dnslist_domain);
3709 if (rc != FAIL) return rc; /* OK or DEFER */
3712 /* If there is a key string, it can be a list of domains or IP addresses to
3713 be concatenated with the main domain. */
3720 uschar keybuffer[256];
3721 uschar keyrevadd[128];
3723 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3724 sizeof(keybuffer))) != NULL)
3726 uschar *prepend = keydomain;
3728 if (string_is_ip_address(keydomain, NULL) != 0)
3730 invert_address(keyrevadd, keydomain);
3731 prepend = keyrevadd;
3734 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3735 bitmask, match_type, defer_return);
3739 dnslist_domain = string_copy(domain_txt);
3740 dnslist_matched = string_copy(keydomain);
3741 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3742 keydomain, dnslist_domain);
3746 /* If the lookup deferred, remember this fact. We keep trying the rest
3747 of the list to see if we get a useful result, and if we don't, we return
3748 DEFER at the end. */
3750 if (rc == DEFER) defer = TRUE;
3751 } /* continue with next keystring domain/address */
3753 if (defer) return DEFER;
3755 } /* continue with next dnsdb outer domain */
3762 /* End of verify.c */