1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
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");
378 smtp_transport_options_block *ob =
379 (smtp_transport_options_block *)(addr->transport->options_block);
381 /* The information wasn't available in the cache, so we have to do a real
382 callout and save the result in the cache for next time, unless no_cache is set,
383 or unless we have a previously cached negative random result. If we are to test
384 with a random local part, ensure that such a local part is available. If not,
385 log the fact, but carry on without randomming. */
387 if (callout_random && callout_random_local_part != NULL)
389 random_local_part = expand_string(callout_random_local_part);
390 if (random_local_part == NULL)
391 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
392 "callout_random_local_part: %s", expand_string_message);
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
408 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
410 /* Now make connections to the hosts and do real callouts. The list of hosts
411 is passed in as an argument. */
413 for (host = host_list; host != NULL && !done; host = host->next)
415 smtp_inblock inblock;
416 smtp_outblock outblock;
419 BOOL send_quit = TRUE;
420 uschar *active_hostname = smtp_active_hostname;
424 BOOL suppress_tls = FALSE;
425 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
426 uschar inbuffer[4096];
427 uschar outbuffer[1024];
428 uschar responsebuffer[4096];
430 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
431 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
433 /* Skip this host if we don't have an IP address for it. */
435 if (host->address == NULL)
437 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
442 /* Check the overall callout timeout */
444 if (time(NULL) - callout_start_time >= callout_overall)
446 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
450 /* Set IPv4 or IPv6 */
452 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
454 /* Expand and interpret the interface and port strings. The latter will not
455 be used if there is a host-specific port (e.g. from a manualroute router).
456 This has to be delayed till now, because they may expand differently for
457 different hosts. If there's a failure, log it, but carry on with the
460 deliver_host = host->name;
461 deliver_host_address = host->address;
462 deliver_domain = addr->domain;
464 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
466 !smtp_get_port(tf->port, addr, &port, US"callout"))
467 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
470 /* Set HELO string according to the protocol */
471 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
472 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
475 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
477 /* Set up the buffer for reading SMTP response packets. */
479 inblock.buffer = inbuffer;
480 inblock.buffersize = sizeof(inbuffer);
481 inblock.ptr = inbuffer;
482 inblock.ptrend = inbuffer;
484 /* Set up the buffer for holding SMTP commands while pipelining */
486 outblock.buffer = outbuffer;
487 outblock.buffersize = sizeof(outbuffer);
488 outblock.ptr = outbuffer;
489 outblock.cmd_count = 0;
490 outblock.authenticating = FALSE;
492 /* Reset the parameters of a TLS session */
493 tls_out.cipher = tls_out.peerdn = NULL;
495 /* Connect to the host; on failure, just loop for the next one, but we
496 set the error for the last one. Use the callout_connect timeout. */
498 tls_retry_connection:
500 inblock.sock = outblock.sock =
501 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
502 /* reconsider DSCP here */
503 if (inblock.sock < 0)
505 addr->message = string_sprintf("could not connect to %s [%s]: %s",
506 host->name, host->address, strerror(errno));
507 deliver_host = deliver_host_address = NULL;
508 deliver_domain = save_deliver_domain;
512 /* Expand the helo_data string to find the host name to use. */
514 if (tf->helo_data != NULL)
516 uschar *s = expand_string(tf->helo_data);
518 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
519 "helo_data value for callout: %s", addr->address,
520 expand_string_message);
521 else active_hostname = s;
524 deliver_host = deliver_host_address = NULL;
525 deliver_domain = save_deliver_domain;
527 /* Wait for initial response, and send HELO. The smtp_write_command()
528 function leaves its command in big_buffer. This is used in error responses.
529 Initialize it in case the connection is rejected. */
531 Ustrcpy(big_buffer, "initial connection");
533 /* Unless ssl-on-connect, wait for the initial greeting */
537 if (!smtps || (smtps && tls_out.active >= 0))
539 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
540 goto RESPONSE_FAILED;
542 /* Not worth checking greeting line for ESMTP support */
543 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
544 host->name, host->address, NULL) != OK))
546 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
551 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
554 ob->tls_tempfail_tryclear = FALSE;
556 else /* all other cases */
561 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
562 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
564 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
566 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
569 goto RESPONSE_FAILED;
575 goto esmtp_retry; /* fallback to HELO */
578 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
580 if (esmtp && !suppress_tls && tls_out.active < 0)
582 if (regex_STARTTLS == NULL) regex_STARTTLS =
583 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
585 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
586 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
593 /* If TLS is available on this connection attempt to
594 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
595 send another EHLO - the server may give a different answer in secure mode. We
596 use a separate buffer for reading the response to STARTTLS so that if it is
597 negative, the original EHLO data is available for subsequent analysis, should
598 the client not be required to use TLS. If the response is bad, copy the buffer
599 for error analysis. */
603 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
604 host->address, NULL) != OK &&
605 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
606 host->address, NULL) != OK
609 uschar buffer2[4096];
611 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
614 /* If there is an I/O error, transmission of this message is deferred. If
615 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
616 false, we also defer. However, if there is a temporary rejection of STARTTLS
617 and tls_tempfail_tryclear is true, or if there is an outright rejection of
618 STARTTLS, we carry on. This means we will try to send the message in clear,
619 unless the host is in hosts_require_tls (tested below). */
621 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
622 ob->command_timeout))
624 if (errno != 0 || buffer2[0] == 0 ||
625 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
627 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
629 goto RESPONSE_FAILED;
633 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
636 int rc = tls_client_start(inblock.sock, host, addr,
637 ob->tls_certificate, ob->tls_privatekey,
639 ob->tls_verify_certificates, ob->tls_crl,
640 ob->tls_require_ciphers,
641 #ifdef EXPERIMENTAL_OCSP
642 ob->hosts_require_ocsp,
644 ob->tls_dh_min_bits, callout);
646 /* TLS negotiation failed; give an error. Try in clear on a new connection,
647 if the options permit it for this host. */
650 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
651 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
652 host->address, NULL) != OK)
654 (void)close(inblock.sock);
655 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
656 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
658 goto tls_retry_connection;
660 /*save_errno = ERRNO_TLSFAILURE;*/
661 /*message = US"failure while setting up TLS session";*/
667 /* TLS session is set up. Copy info for logging. */
668 addr->cipher = tls_out.cipher;
669 addr->peerdn = tls_out.peerdn;
671 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
673 goto smtps_redo_greeting;
675 /* For STARTTLS we need to redo EHLO */
680 /* If the host is required to use a secure channel, ensure that we have one. */
681 if (tls_out.active < 0)
682 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
683 host->address, NULL) == OK)
685 /*save_errno = ERRNO_TLSREQUIRED;*/
686 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
687 host->name, host->address,
688 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
693 #endif /*SUPPORT_TLS*/
695 done = TRUE; /* so far so good; have response to HELO */
697 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
699 /* For now, transport_filter by cutthrough-delivery is not supported */
700 /* Need proper integration with the proper transport mechanism. */
701 if (cutthrough_delivery)
703 if (addr->transport->filter_command)
705 cutthrough_delivery= FALSE;
706 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
710 cutthrough_delivery= FALSE;
711 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
719 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
722 /* Failure to accept HELO is cached; this blocks the whole domain for all
723 senders. I/O errors and defer responses are not cached. */
727 *failure_ptr = US"mail"; /* At or before MAIL */
728 if (errno == 0 && responsebuffer[0] == '5')
730 setflag(addr, af_verify_nsfail);
731 new_domain_record.result = ccache_reject;
735 /* If we haven't authenticated, but are required to, give up. */
738 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
739 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
741 /* Copy AUTH info for logging */
742 ( (addr->authenticator = client_authenticator),
743 (addr->auth_id = client_authenticated_id),
745 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
746 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
749 ( (addr->auth_sndr = client_authenticated_sender),
751 /* Send the MAIL command */
752 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
753 from_address, responsebuffer) >= 0)
756 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
759 /* If the host does not accept MAIL FROM:<>, arrange to cache this
760 information, but again, don't record anything for an I/O error or a defer. Do
761 not cache rejections of MAIL when a non-empty sender has been used, because
762 that blocks the whole domain for all senders. */
766 *failure_ptr = US"mail"; /* At or before MAIL */
767 if (errno == 0 && responsebuffer[0] == '5')
769 setflag(addr, af_verify_nsfail);
770 if (from_address[0] == 0)
771 new_domain_record.result = ccache_reject_mfnull;
775 /* Otherwise, proceed to check a "random" address (if required), then the
776 given address, and the postmaster address (if required). Between each check,
777 issue RSET, because some servers accept only one recipient after MAIL
780 Before doing this, set the result in the domain cache record to "accept",
781 unless its previous value was ccache_reject_mfnull. In that case, the domain
782 rejects MAIL FROM:<> and we want to continue to remember that. When that is
783 the case, we have got here only in the case of a recipient verification with
784 a non-null sender. */
788 new_domain_record.result =
789 (old_domain_cache_result == ccache_reject_mfnull)?
790 ccache_reject_mfnull: ccache_accept;
792 /* Do the random local part check first */
794 if (random_local_part != NULL)
796 uschar randombuffer[1024];
798 smtp_write_command(&outblock, FALSE,
799 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
800 addr->domain) >= 0 &&
801 smtp_read_response(&inblock, randombuffer,
802 sizeof(randombuffer), '2', callout);
804 /* Remember when we last did a random test */
806 new_domain_record.random_stamp = time(NULL);
808 /* If accepted, we aren't going to do any further tests below. */
812 new_domain_record.random_result = ccache_accept;
815 /* Otherwise, cache a real negative response, and get back to the right
816 state to send RCPT. Unless there's some problem such as a dropped
817 connection, we expect to succeed, because the commands succeeded above. */
821 if (randombuffer[0] == '5')
822 new_domain_record.random_result = ccache_reject;
825 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
826 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
829 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
830 from_address) >= 0 &&
831 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
834 else done = FALSE; /* Some timeout/connection problem */
837 /* If the host is accepting all local parts, as determined by the "random"
838 check, we don't need to waste time doing any further checking. */
840 if (new_domain_record.random_result != ccache_accept && done)
842 /* Get the rcpt_include_affixes flag from the transport if there is one,
843 but assume FALSE if there is not. */
846 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
847 transport_rcpt_address(addr,
848 (addr->transport == NULL)? FALSE :
849 addr->transport->rcpt_include_affixes)) >= 0 &&
850 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
854 new_address_record.result = ccache_accept;
855 else if (errno == 0 && responsebuffer[0] == '5')
857 *failure_ptr = US"recipient";
858 new_address_record.result = ccache_reject;
861 /* Do postmaster check if requested; if a full check is required, we
862 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
864 if (done && pm_mailfrom != NULL)
866 /*XXX not suitable for cutthrough - sequencing problems */
867 cutthrough_delivery= FALSE;
868 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
871 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
872 smtp_read_response(&inblock, responsebuffer,
873 sizeof(responsebuffer), '2', callout) &&
875 smtp_write_command(&outblock, FALSE,
876 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
877 smtp_read_response(&inblock, responsebuffer,
878 sizeof(responsebuffer), '2', callout) &&
880 /* First try using the current domain */
883 smtp_write_command(&outblock, FALSE,
884 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
885 smtp_read_response(&inblock, responsebuffer,
886 sizeof(responsebuffer), '2', callout)
891 /* If that doesn't work, and a full check is requested,
892 try without the domain. */
895 (options & vopt_callout_fullpm) != 0 &&
896 smtp_write_command(&outblock, FALSE,
897 "RCPT TO:<postmaster>\r\n") >= 0 &&
898 smtp_read_response(&inblock, responsebuffer,
899 sizeof(responsebuffer), '2', callout)
902 /* Sort out the cache record */
904 new_domain_record.postmaster_stamp = time(NULL);
907 new_domain_record.postmaster_result = ccache_accept;
908 else if (errno == 0 && responsebuffer[0] == '5')
910 *failure_ptr = US"postmaster";
911 setflag(addr, af_verify_pmfail);
912 new_domain_record.postmaster_result = ccache_reject;
915 } /* Random not accepted */
916 } /* MAIL FROM: accepted */
918 /* For any failure of the main check, other than a negative response, we just
919 close the connection and carry on. We can identify a negative response by the
920 fact that errno is zero. For I/O errors it will be non-zero
922 Set up different error texts for logging and for sending back to the caller
923 as an SMTP response. Log in all cases, using a one-line format. For sender
924 callouts, give a full response to the caller, but for recipient callouts,
925 don't give the IP address because this may be an internal host whose identity
926 is not to be widely broadcast. */
930 if (errno == ETIMEDOUT)
932 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
937 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
940 string_sprintf("response to \"%s\" from %s [%s] was: %s",
941 big_buffer, host->name, host->address,
942 string_printing(responsebuffer));
944 addr->user_message = is_recipient?
945 string_sprintf("Callout verification failed:\n%s", responsebuffer)
947 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
948 host->address, big_buffer, responsebuffer);
950 /* Hard rejection ends the process */
952 if (responsebuffer[0] == '5') /* Address rejected */
960 /* End the SMTP conversation and close the connection. */
962 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
963 and we have no cutthrough conn so far
964 here is where we want to leave the conn open */
965 if ( cutthrough_delivery
968 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
969 && !random_local_part
974 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
975 cutthrough_addr = *addr; /* Save the address_item for later logging */
976 cutthrough_addr.host_used = store_get(sizeof(host_item));
977 cutthrough_addr.host_used->name = host->name;
978 cutthrough_addr.host_used->address = host->address;
979 cutthrough_addr.host_used->port = port;
981 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
982 ctblock.buffer = ctbuffer;
983 ctblock.buffersize = sizeof(ctbuffer);
984 ctblock.ptr = ctbuffer;
985 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
986 ctblock.sock = cutthrough_fd;
990 /* Ensure no cutthrough on multiple address verifies */
991 if (options & vopt_callout_recipsender)
992 cancel_cutthrough_connection("multiple verify calls");
993 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
996 tls_close(FALSE, TRUE);
998 (void)close(inblock.sock);
1001 } /* Loop through all hosts, while !done */
1004 /* If we get here with done == TRUE, a successful callout happened, and yield
1005 will be set OK or FAIL according to the response to the RCPT command.
1006 Otherwise, we looped through the hosts but couldn't complete the business.
1007 However, there may be domain-specific information to cache in both cases.
1009 The value of the result field in the new_domain record is ccache_unknown if
1010 there was an error before or with MAIL FROM:, and errno was not zero,
1011 implying some kind of I/O error. We don't want to write the cache in that case.
1012 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1014 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1016 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1019 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1023 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1024 (int)sizeof(dbdata_callout_cache));
1025 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1026 " result=%d postmaster=%d random=%d\n",
1027 new_domain_record.result,
1028 new_domain_record.postmaster_result,
1029 new_domain_record.random_result);
1033 /* If a definite result was obtained for the callout, cache it unless caching
1038 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1040 if (dbm_file == NULL)
1041 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1042 if (dbm_file == NULL)
1044 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1048 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1049 (int)sizeof(dbdata_callout_cache_address));
1050 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1051 (new_address_record.result == ccache_accept)? "positive" : "negative");
1056 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1057 temporary error. If there was only one host, and a response was received, leave
1058 it alone if supplying details. Otherwise, give a generic response. */
1062 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1063 is_recipient? "recipient" : "sender");
1066 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1068 addr->user_message = (!smtp_return_error_details)? dullmsg :
1069 string_sprintf("%s for <%s>.\n"
1070 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1071 "they may be permanently unreachable from this server. In the latter case,\n%s",
1072 dullmsg, addr->address,
1074 "the address will never be accepted."
1076 "you need to change the address or create an MX record for its domain\n"
1077 "if it is supposed to be generally accessible from the Internet.\n"
1078 "Talk to your mail administrator for details.");
1080 /* Force a specific error code */
1082 addr->basic_errno = ERRNO_CALLOUTDEFER;
1085 /* Come here from within the cache-reading code on fast-track exit. */
1088 if (dbm_file != NULL) dbfn_close(dbm_file);
1094 /* Called after recipient-acl to get a cutthrough connection open when
1095 one was requested and a recipient-verify wasn't subsequently done.
1098 open_cutthrough_connection( address_item * addr )
1102 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1103 /* We must use a copy of the address for verification, because it might
1107 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1108 (void) verify_address(&addr2, NULL,
1109 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1110 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1112 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1118 /* Send given number of bytes from the buffer */
1120 cutthrough_send(int n)
1122 if(cutthrough_fd < 0)
1127 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1129 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1132 transport_count += n;
1133 ctblock.ptr= ctblock.buffer;
1137 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1144 _cutthrough_puts(uschar * cp, int n)
1148 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1149 if(!cutthrough_send(ctblock.buffersize))
1152 *ctblock.ptr++ = *cp++;
1157 /* Buffered output of counted data block. Return boolean success */
1159 cutthrough_puts(uschar * cp, int n)
1161 if (cutthrough_fd < 0) return TRUE;
1162 if (_cutthrough_puts(cp, n)) return TRUE;
1163 cancel_cutthrough_connection("transmit failed");
1169 _cutthrough_flush_send( void )
1171 int n= ctblock.ptr-ctblock.buffer;
1174 if(!cutthrough_send(n))
1180 /* Send out any bufferred output. Return boolean success. */
1182 cutthrough_flush_send( void )
1184 if (_cutthrough_flush_send()) return TRUE;
1185 cancel_cutthrough_connection("transmit failed");
1191 cutthrough_put_nl( void )
1193 return cutthrough_puts(US"\r\n", 2);
1197 /* Get and check response from cutthrough target */
1199 cutthrough_response(char expect, uschar ** copy)
1201 smtp_inblock inblock;
1202 uschar inbuffer[4096];
1203 uschar responsebuffer[4096];
1205 inblock.buffer = inbuffer;
1206 inblock.buffersize = sizeof(inbuffer);
1207 inblock.ptr = inbuffer;
1208 inblock.ptrend = inbuffer;
1209 inblock.sock = cutthrough_fd;
1210 /* this relies on (inblock.sock == tls_out.active) */
1211 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1212 cancel_cutthrough_connection("target timeout on read");
1217 *copy= cp= string_copy(responsebuffer);
1218 /* Trim the trailing end of line */
1219 cp += Ustrlen(responsebuffer);
1220 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1221 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1224 return responsebuffer[0];
1228 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1230 cutthrough_predata( void )
1232 if(cutthrough_fd < 0)
1235 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1236 cutthrough_puts(US"DATA\r\n", 6);
1237 cutthrough_flush_send();
1239 /* Assume nothing buffered. If it was it gets ignored. */
1240 return cutthrough_response('3', NULL) == '3';
1244 /* Buffered send of headers. Return success boolean. */
1245 /* Expands newlines to wire format (CR,NL). */
1246 /* Also sends header-terminating blank line. */
1248 cutthrough_headers_send( void )
1251 uschar * cp1, * cp2;
1253 if(cutthrough_fd < 0)
1256 for(h= header_list; h != NULL; h= h->next)
1257 if(h->type != htype_old && h->text != NULL)
1258 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1259 if( !cutthrough_puts(cp1, cp2-cp1)
1260 || !cutthrough_put_nl())
1263 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1264 return cutthrough_put_nl();
1269 close_cutthrough_connection( const char * why )
1271 if(cutthrough_fd >= 0)
1273 /* We could be sending this after a bunch of data, but that is ok as
1274 the only way to cancel the transfer in dataphase is to drop the tcp
1275 conn before the final dot.
1277 ctblock.ptr = ctbuffer;
1278 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1279 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1280 _cutthrough_flush_send();
1281 /* No wait for response */
1284 tls_close(FALSE, TRUE);
1286 (void)close(cutthrough_fd);
1288 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1290 ctblock.ptr = ctbuffer;
1294 cancel_cutthrough_connection( const char * why )
1296 close_cutthrough_connection(why);
1297 cutthrough_delivery= FALSE;
1303 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1304 Log an OK response as a transmission.
1305 Close the connection.
1306 Return smtp response-class digit.
1309 cutthrough_finaldot( void )
1311 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1313 /* Assume data finshed with new-line */
1314 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1315 return cutthrough_addr.message;
1317 switch(cutthrough_response('2', &cutthrough_addr.message))
1320 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1321 close_cutthrough_connection("delivered");
1325 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1329 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1335 return cutthrough_addr.message;
1340 /*************************************************
1341 * Copy error to toplevel address *
1342 *************************************************/
1344 /* This function is used when a verify fails or defers, to ensure that the
1345 failure or defer information is in the original toplevel address. This applies
1346 when an address is redirected to a single new address, and the failure or
1347 deferral happens to the child address.
1350 vaddr the verify address item
1351 addr the final address item
1354 Returns: the value of YIELD
1358 copy_error(address_item *vaddr, address_item *addr, int yield)
1362 vaddr->message = addr->message;
1363 vaddr->user_message = addr->user_message;
1364 vaddr->basic_errno = addr->basic_errno;
1365 vaddr->more_errno = addr->more_errno;
1366 vaddr->p.address_data = addr->p.address_data;
1367 copyflag(vaddr, addr, af_pass_message);
1375 /**************************************************
1376 * printf that automatically handles TLS if needed *
1377 ***************************************************/
1379 /* This function is used by verify_address() as a substitute for all fprintf()
1380 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1381 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1382 that assumes that we always use the smtp_out FILE* when not using TLS or the
1383 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1384 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1388 f the candidate FILE* to write to
1389 format format string
1390 ... optional arguments
1396 static void PRINTF_FUNCTION(2,3)
1397 respond_printf(FILE *f, const char *format, ...)
1401 va_start(ap, format);
1402 if (smtp_out && (f == smtp_out))
1403 smtp_vprintf(format, ap);
1405 vfprintf(f, format, ap);
1411 /*************************************************
1412 * Verify an email address *
1413 *************************************************/
1415 /* This function is used both for verification (-bv and at other times) and
1416 address testing (-bt), which is indicated by address_test_mode being set.
1419 vaddr contains the address to verify; the next field in this block
1421 f if not NULL, write the result to this file
1422 options various option bits:
1423 vopt_fake_sender => this sender verify is not for the real
1424 sender (it was verify=sender=xxxx or an address from a
1425 header line) - rewriting must not change sender_address
1426 vopt_is_recipient => this is a recipient address, otherwise
1427 it's a sender address - this affects qualification and
1428 rewriting and messages from callouts
1429 vopt_qualify => qualify an unqualified address; else error
1430 vopt_expn => called from SMTP EXPN command
1431 vopt_success_on_redirect => when a new address is generated
1432 the verification instantly succeeds
1434 These ones are used by do_callout() -- the options variable
1437 vopt_callout_fullpm => if postmaster check, do full one
1438 vopt_callout_no_cache => don't use callout cache
1439 vopt_callout_random => do the "random" thing
1440 vopt_callout_recipsender => use real sender for recipient
1441 vopt_callout_recippmaster => use postmaster for recipient
1443 callout if > 0, specifies that callout is required, and gives timeout
1444 for individual commands
1445 callout_overall if > 0, gives overall timeout for the callout function;
1446 if < 0, a default is used (see do_callout())
1447 callout_connect the connection timeout for callouts
1448 se_mailfrom when callout is requested to verify a sender, use this
1449 in MAIL FROM; NULL => ""
1450 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1451 thing and use this as the sender address (may be "")
1453 routed if not NULL, set TRUE if routing succeeded, so we can
1454 distinguish between routing failed and callout failed
1456 Returns: OK address verified
1457 FAIL address failed to verify
1458 DEFER can't tell at present
1462 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1463 int callout_overall, int callout_connect, uschar *se_mailfrom,
1464 uschar *pm_mailfrom, BOOL *routed)
1467 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1468 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1469 BOOL expn = (options & vopt_expn) != 0;
1470 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1473 int verify_type = expn? v_expn :
1474 address_test_mode? v_none :
1475 is_recipient? v_recipient : v_sender;
1476 address_item *addr_list;
1477 address_item *addr_new = NULL;
1478 address_item *addr_remote = NULL;
1479 address_item *addr_local = NULL;
1480 address_item *addr_succeed = NULL;
1481 uschar **failure_ptr = is_recipient?
1482 &recipient_verify_failure : &sender_verify_failure;
1483 uschar *ko_prefix, *cr;
1484 uschar *address = vaddr->address;
1485 uschar *save_sender;
1486 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1488 /* Clear, just in case */
1490 *failure_ptr = NULL;
1492 /* Set up a prefix and suffix for error message which allow us to use the same
1493 output statements both in EXPN mode (where an SMTP response is needed) and when
1494 debugging with an output file. */
1498 ko_prefix = US"553 ";
1501 else ko_prefix = cr = US"";
1503 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1505 if (parse_find_at(address) == NULL)
1507 if ((options & vopt_qualify) == 0)
1510 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1511 ko_prefix, address, cr);
1512 *failure_ptr = US"qualify";
1515 address = rewrite_address_qualify(address, is_recipient);
1520 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1521 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1524 /* Rewrite and report on it. Clear the domain and local part caches - these
1525 may have been set by domains and local part tests during an ACL. */
1527 if (global_rewrite_rules != NULL)
1529 uschar *old = address;
1530 address = rewrite_address(address, is_recipient, FALSE,
1531 global_rewrite_rules, rewrite_existflags);
1534 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1535 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1536 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1540 /* If this is the real sender address, we must update sender_address at
1541 this point, because it may be referred to in the routers. */
1543 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1544 sender_address = address;
1546 /* If the address was rewritten to <> no verification can be done, and we have
1547 to return OK. This rewriting is permitted only for sender addresses; for other
1548 addresses, such rewriting fails. */
1550 if (address[0] == 0) return OK;
1552 /* Flip the legacy TLS-related variables over to the outbound set in case
1553 they're used in the context of a transport used by verification. Reset them
1554 at exit from this routine. */
1556 modify_variable(US"tls_bits", &tls_out.bits);
1557 modify_variable(US"tls_certificate_verified", &tls_out.certificate_verified);
1558 modify_variable(US"tls_cipher", &tls_out.cipher);
1559 modify_variable(US"tls_peerdn", &tls_out.peerdn);
1560 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1561 modify_variable(US"tls_sni", &tls_out.sni);
1564 /* Save a copy of the sender address for re-instating if we change it to <>
1565 while verifying a sender address (a nice bit of self-reference there). */
1567 save_sender = sender_address;
1569 /* Update the address structure with the possibly qualified and rewritten
1570 address. Set it up as the starting address on the chain of new addresses. */
1572 vaddr->address = address;
1575 /* We need a loop, because an address can generate new addresses. We must also
1576 cope with generated pipes and files at the top level. (See also the code and
1577 comment in deliver.c.) However, it is usually the case that the router for
1578 user's .forward files has its verify flag turned off.
1580 If an address generates more than one child, the loop is used only when
1581 full_info is set, and this can only be set locally. Remote enquiries just get
1582 information about the top level address, not anything that it generated. */
1584 while (addr_new != NULL)
1587 address_item *addr = addr_new;
1589 addr_new = addr->next;
1594 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1595 debug_printf("Considering %s\n", addr->address);
1598 /* Handle generated pipe, file or reply addresses. We don't get these
1599 when handling EXPN, as it does only one level of expansion. */
1601 if (testflag(addr, af_pfr))
1608 if (addr->address[0] == '>')
1610 allow = testflag(addr, af_allow_reply);
1611 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1615 allow = (addr->address[0] == '|')?
1616 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1617 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1620 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1621 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1622 "%s\n", addr->message);
1624 fprintf(f, "\n transport = %s\n", addr->transport->name);
1626 fprintf(f, " *** forbidden ***\n");
1631 /* Just in case some router parameter refers to it. */
1633 return_path = (addr->p.errors_address != NULL)?
1634 addr->p.errors_address : sender_address;
1636 /* Split the address into domain and local part, handling the %-hack if
1637 necessary, and then route it. While routing a sender address, set
1638 $sender_address to <> because that is what it will be if we were trying to
1639 send a bounce to the sender. */
1641 if (routed != NULL) *routed = FALSE;
1642 if ((rc = deliver_split_address(addr)) == OK)
1644 if (!is_recipient) sender_address = null_sender;
1645 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1646 &addr_succeed, verify_type);
1647 sender_address = save_sender; /* Put back the real sender */
1650 /* If routing an address succeeded, set the flag that remembers, for use when
1651 an ACL cached a sender verify (in case a callout fails). Then if routing set
1652 up a list of hosts or the transport has a host list, and the callout option
1653 is set, and we aren't in a host checking run, do the callout verification,
1654 and set another flag that notes that a callout happened. */
1658 if (routed != NULL) *routed = TRUE;
1661 host_item *host_list = addr->host_list;
1663 /* Make up some data for use in the case where there is no remote
1666 transport_feedback tf = {
1667 NULL, /* interface (=> any) */
1668 US"smtp", /* port */
1669 US"smtp", /* protocol */
1671 US"$smtp_active_hostname", /* helo_data */
1672 FALSE, /* hosts_override */
1673 FALSE, /* hosts_randomize */
1674 FALSE, /* gethostbyname */
1675 TRUE, /* qualify_single */
1676 FALSE /* search_parents */
1679 /* If verification yielded a remote transport, we want to use that
1680 transport's options, so as to mimic what would happen if we were really
1681 sending a message to this address. */
1683 if (addr->transport != NULL && !addr->transport->info->local)
1685 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1687 /* If the transport has hosts and the router does not, or if the
1688 transport is configured to override the router's hosts, we must build a
1689 host list of the transport's hosts, and find the IP addresses */
1691 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1694 uschar *save_deliver_domain = deliver_domain;
1695 uschar *save_deliver_localpart = deliver_localpart;
1697 host_list = NULL; /* Ignore the router's hosts */
1699 deliver_domain = addr->domain;
1700 deliver_localpart = addr->local_part;
1701 s = expand_string(tf.hosts);
1702 deliver_domain = save_deliver_domain;
1703 deliver_localpart = save_deliver_localpart;
1707 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1708 "\"%s\" in %s transport for callout: %s", tf.hosts,
1709 addr->transport->name, expand_string_message);
1714 uschar *canonical_name;
1715 host_item *host, *nexthost;
1716 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1718 /* Just ignore failures to find a host address. If we don't manage
1719 to find any addresses, the callout will defer. Note that more than
1720 one address may be found for a single host, which will result in
1721 additional host items being inserted into the chain. Hence we must
1722 save the next host first. */
1724 flags = HOST_FIND_BY_A;
1725 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1726 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1728 for (host = host_list; host != NULL; host = nexthost)
1730 nexthost = host->next;
1731 if (tf.gethostbyname ||
1732 string_is_ip_address(host->name, NULL) != 0)
1733 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1735 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1736 &canonical_name, NULL);
1742 /* Can only do a callout if we have at least one host! If the callout
1743 fails, it will have set ${sender,recipient}_verify_failure. */
1745 if (host_list != NULL)
1747 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1748 if (host_checking && !host_checking_callout)
1751 debug_printf("... callout omitted by default when host testing\n"
1752 "(Use -bhc if you want the callouts to happen.)\n");
1757 deliver_set_expansions(addr);
1759 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1760 callout_connect, options, se_mailfrom, pm_mailfrom);
1765 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1766 "transport provided a host list\n");
1771 /* Otherwise, any failure is a routing failure */
1773 else *failure_ptr = US"route";
1775 /* A router may return REROUTED if it has set up a child address as a result
1776 of a change of domain name (typically from widening). In this case we always
1777 want to continue to verify the new child. */
1779 if (rc == REROUTED) continue;
1781 /* Handle hard failures */
1788 address_item *p = addr->parent;
1790 respond_printf(f, "%s%s %s", ko_prefix,
1791 full_info? addr->address : address,
1792 address_test_mode? "is undeliverable" : "failed to verify");
1793 if (!expn && admin_user)
1795 if (addr->basic_errno > 0)
1796 respond_printf(f, ": %s", strerror(addr->basic_errno));
1797 if (addr->message != NULL)
1798 respond_printf(f, ": %s", addr->message);
1801 /* Show parents iff doing full info */
1803 if (full_info) while (p != NULL)
1805 respond_printf(f, "%s\n <-- %s", cr, p->address);
1808 respond_printf(f, "%s\n", cr);
1810 cancel_cutthrough_connection("routing hard fail");
1814 yield = copy_error(vaddr, addr, FAIL);
1822 else if (rc == DEFER)
1827 address_item *p = addr->parent;
1828 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1829 full_info? addr->address : address);
1830 if (!expn && admin_user)
1832 if (addr->basic_errno > 0)
1833 respond_printf(f, ": %s", strerror(addr->basic_errno));
1834 if (addr->message != NULL)
1835 respond_printf(f, ": %s", addr->message);
1836 else if (addr->basic_errno <= 0)
1837 respond_printf(f, ": unknown error");
1840 /* Show parents iff doing full info */
1842 if (full_info) while (p != NULL)
1844 respond_printf(f, "%s\n <-- %s", cr, p->address);
1847 respond_printf(f, "%s\n", cr);
1849 cancel_cutthrough_connection("routing soft fail");
1853 yield = copy_error(vaddr, addr, DEFER);
1856 else if (yield == OK) yield = DEFER;
1859 /* If we are handling EXPN, we do not want to continue to route beyond
1860 the top level (whose address is in "address"). */
1864 uschar *ok_prefix = US"250-";
1865 if (addr_new == NULL)
1867 if (addr_local == NULL && addr_remote == NULL)
1868 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1870 respond_printf(f, "250 <%s>\r\n", address);
1872 else while (addr_new != NULL)
1874 address_item *addr2 = addr_new;
1875 addr_new = addr2->next;
1876 if (addr_new == NULL) ok_prefix = US"250 ";
1877 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1883 /* Successful routing other than EXPN. */
1887 /* Handle successful routing when short info wanted. Otherwise continue for
1888 other (generated) addresses. Short info is the operational case. Full info
1889 can be requested only when debug_selector != 0 and a file is supplied.
1891 There is a conflict between the use of aliasing as an alternate email
1892 address, and as a sort of mailing list. If an alias turns the incoming
1893 address into just one address (e.g. J.Caesar->jc44) you may well want to
1894 carry on verifying the generated address to ensure it is valid when
1895 checking incoming mail. If aliasing generates multiple addresses, you
1896 probably don't want to do this. Exim therefore treats the generation of
1897 just a single new address as a special case, and continues on to verify the
1898 generated address. */
1900 if (!full_info && /* Stop if short info wanted AND */
1901 (((addr_new == NULL || /* No new address OR */
1902 addr_new->next != NULL || /* More than one new address OR */
1903 testflag(addr_new, af_pfr))) /* New address is pfr */
1905 (addr_new != NULL && /* At least one new address AND */
1906 success_on_redirect))) /* success_on_redirect is set */
1908 if (f != NULL) fprintf(f, "%s %s\n", address,
1909 address_test_mode? "is deliverable" : "verified");
1911 /* If we have carried on to verify a child address, we want the value
1912 of $address_data to be that of the child */
1914 vaddr->p.address_data = addr->p.address_data;
1919 } /* Loop for generated addresses */
1921 /* Display the full results of the successful routing, including any generated
1922 addresses. Control gets here only when full_info is set, which requires f not
1923 to be NULL, and this occurs only when a top-level verify is called with the
1924 debugging switch on.
1926 If there are no local and no remote addresses, and there were no pipes, files,
1927 or autoreplies, and there were no errors or deferments, the message is to be
1928 discarded, usually because of the use of :blackhole: in an alias file. */
1930 if (allok && addr_local == NULL && addr_remote == NULL)
1932 fprintf(f, "mail to %s is discarded\n", address);
1936 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1938 while (addr_list != NULL)
1940 address_item *addr = addr_list;
1941 address_item *p = addr->parent;
1942 addr_list = addr->next;
1944 fprintf(f, "%s", CS addr->address);
1945 #ifdef EXPERIMENTAL_SRS
1946 if(addr->p.srs_sender)
1947 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1950 /* If the address is a duplicate, show something about it. */
1952 if (!testflag(addr, af_pfr))
1955 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1956 fprintf(f, " [duplicate, would not be delivered]");
1957 else tree_add_duplicate(addr->unique, addr);
1960 /* Now show its parents */
1964 fprintf(f, "\n <-- %s", p->address);
1969 /* Show router, and transport */
1971 fprintf(f, "router = %s, ", addr->router->name);
1972 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1973 addr->transport->name);
1975 /* Show any hosts that are set up by a router unless the transport
1976 is going to override them; fiddle a bit to get a nice format. */
1978 if (addr->host_list != NULL && addr->transport != NULL &&
1979 !addr->transport->overrides_hosts)
1984 for (h = addr->host_list; h != NULL; h = h->next)
1986 int len = Ustrlen(h->name);
1987 if (len > maxlen) maxlen = len;
1988 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1989 if (len > maxaddlen) maxaddlen = len;
1991 for (h = addr->host_list; h != NULL; h = h->next)
1993 int len = Ustrlen(h->name);
1994 fprintf(f, " host %s ", h->name);
1995 while (len++ < maxlen) fprintf(f, " ");
1996 if (h->address != NULL)
1998 fprintf(f, "[%s] ", h->address);
1999 len = Ustrlen(h->address);
2001 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2003 fprintf(f, "[unknown] ");
2007 while (len++ < maxaddlen) fprintf(f," ");
2008 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2009 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2010 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2017 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2018 the -bv or -bt case). */
2022 modify_variable(US"tls_bits", &tls_in.bits);
2023 modify_variable(US"tls_certificate_verified", &tls_in.certificate_verified);
2024 modify_variable(US"tls_cipher", &tls_in.cipher);
2025 modify_variable(US"tls_peerdn", &tls_in.peerdn);
2026 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
2027 modify_variable(US"tls_sni", &tls_in.sni);
2036 /*************************************************
2037 * Check headers for syntax errors *
2038 *************************************************/
2040 /* This function checks those header lines that contain addresses, and verifies
2041 that all the addresses therein are syntactially correct.
2044 msgptr where to put an error message
2051 verify_check_headers(uschar **msgptr)
2057 for (h = header_list; h != NULL && yield == OK; h = h->next)
2059 if (h->type != htype_from &&
2060 h->type != htype_reply_to &&
2061 h->type != htype_sender &&
2062 h->type != htype_to &&
2063 h->type != htype_cc &&
2064 h->type != htype_bcc)
2067 colon = Ustrchr(h->text, ':');
2069 while (isspace(*s)) s++;
2071 /* Loop for multiple addresses in the header, enabling group syntax. Note
2072 that we have to reset this after the header has been scanned. */
2074 parse_allow_group = TRUE;
2078 uschar *ss = parse_find_address_end(s, FALSE);
2079 uschar *recipient, *errmess;
2080 int terminator = *ss;
2081 int start, end, domain;
2083 /* Temporarily terminate the string at this point, and extract the
2084 operative address within, allowing group syntax. */
2087 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2090 /* Permit an unqualified address only if the message is local, or if the
2091 sending host is configured to be permitted to send them. */
2093 if (recipient != NULL && domain == 0)
2095 if (h->type == htype_from || h->type == htype_sender)
2097 if (!allow_unqualified_sender) recipient = NULL;
2101 if (!allow_unqualified_recipient) recipient = NULL;
2103 if (recipient == NULL) errmess = US"unqualified address not permitted";
2106 /* It's an error if no address could be extracted, except for the special
2107 case of an empty address. */
2109 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2111 uschar *verb = US"is";
2116 /* Arrange not to include any white space at the end in the
2117 error message or the header name. */
2119 while (t > s && isspace(t[-1])) t--;
2120 while (tt > h->text && isspace(tt[-1])) tt--;
2122 /* Add the address that failed to the error message, since in a
2123 header with very many addresses it is sometimes hard to spot
2124 which one is at fault. However, limit the amount of address to
2125 quote - cases have been seen where, for example, a missing double
2126 quote in a humungous To: header creates an "address" that is longer
2127 than string_sprintf can handle. */
2136 *msgptr = string_printing(
2137 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2138 errmess, tt - h->text, h->text, verb, len, s));
2141 break; /* Out of address loop */
2144 /* Advance to the next address */
2146 s = ss + (terminator? 1:0);
2147 while (isspace(*s)) s++;
2148 } /* Next address */
2150 parse_allow_group = FALSE;
2151 parse_found_group = FALSE;
2152 } /* Next header unless yield has been set FALSE */
2159 /*************************************************
2160 * Check for blind recipients *
2161 *************************************************/
2163 /* This function checks that every (envelope) recipient is mentioned in either
2164 the To: or Cc: header lines, thus detecting blind carbon copies.
2166 There are two ways of scanning that could be used: either scan the header lines
2167 and tick off the recipients, or scan the recipients and check the header lines.
2168 The original proposed patch did the former, but I have chosen to do the latter,
2169 because (a) it requires no memory and (b) will use fewer resources when there
2170 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2173 Returns: OK if there are no blind recipients
2174 FAIL if there is at least one blind recipient
2178 verify_check_notblind(void)
2181 for (i = 0; i < recipients_count; i++)
2185 uschar *address = recipients_list[i].address;
2187 for (h = header_list; !found && h != NULL; h = h->next)
2191 if (h->type != htype_to && h->type != htype_cc) continue;
2193 colon = Ustrchr(h->text, ':');
2195 while (isspace(*s)) s++;
2197 /* Loop for multiple addresses in the header, enabling group syntax. Note
2198 that we have to reset this after the header has been scanned. */
2200 parse_allow_group = TRUE;
2204 uschar *ss = parse_find_address_end(s, FALSE);
2205 uschar *recipient,*errmess;
2206 int terminator = *ss;
2207 int start, end, domain;
2209 /* Temporarily terminate the string at this point, and extract the
2210 operative address within, allowing group syntax. */
2213 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2216 /* If we found a valid recipient that has a domain, compare it with the
2217 envelope recipient. Local parts are compared case-sensitively, domains
2218 case-insensitively. By comparing from the start with length "domain", we
2219 include the "@" at the end, which ensures that we are comparing the whole
2220 local part of each address. */
2222 if (recipient != NULL && domain != 0)
2224 found = Ustrncmp(recipient, address, domain) == 0 &&
2225 strcmpic(recipient + domain, address + domain) == 0;
2229 /* Advance to the next address */
2231 s = ss + (terminator? 1:0);
2232 while (isspace(*s)) s++;
2233 } /* Next address */
2235 parse_allow_group = FALSE;
2236 parse_found_group = FALSE;
2237 } /* Next header (if found is false) */
2239 if (!found) return FAIL;
2240 } /* Next recipient */
2247 /*************************************************
2248 * Find if verified sender *
2249 *************************************************/
2251 /* Usually, just a single address is verified as the sender of the message.
2252 However, Exim can be made to verify other addresses as well (often related in
2253 some way), and this is useful in some environments. There may therefore be a
2254 chain of such addresses that have previously been tested. This function finds
2255 whether a given address is on the chain.
2257 Arguments: the address to be verified
2258 Returns: pointer to an address item, or NULL
2262 verify_checked_sender(uschar *sender)
2265 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2266 if (Ustrcmp(sender, addr->address) == 0) break;
2274 /*************************************************
2275 * Get valid header address *
2276 *************************************************/
2278 /* Scan the originator headers of the message, looking for an address that
2279 verifies successfully. RFC 822 says:
2281 o The "Sender" field mailbox should be sent notices of
2282 any problems in transport or delivery of the original
2283 messages. If there is no "Sender" field, then the
2284 "From" field mailbox should be used.
2286 o If the "Reply-To" field exists, then the reply should
2287 go to the addresses indicated in that field and not to
2288 the address(es) indicated in the "From" field.
2290 So we check a Sender field if there is one, else a Reply_to field, else a From
2291 field. As some strange messages may have more than one of these fields,
2292 especially if they are resent- fields, check all of them if there is more than
2296 user_msgptr points to where to put a user error message
2297 log_msgptr points to where to put a log error message
2298 callout timeout for callout check (passed to verify_address())
2299 callout_overall overall callout timeout (ditto)
2300 callout_connect connect callout timeout (ditto)
2301 se_mailfrom mailfrom for verify; NULL => ""
2302 pm_mailfrom sender for pm callout check (passed to verify_address())
2303 options callout options (passed to verify_address())
2304 verrno where to put the address basic_errno
2306 If log_msgptr is set to something without setting user_msgptr, the caller
2307 normally uses log_msgptr for both things.
2309 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2310 FAIL is given if no appropriate headers are found
2314 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2315 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2316 uschar *pm_mailfrom, int options, int *verrno)
2318 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2323 for (i = 0; i < 3 && !done; i++)
2326 for (h = header_list; h != NULL && !done; h = h->next)
2328 int terminator, new_ok;
2329 uschar *s, *ss, *endname;
2331 if (h->type != header_types[i]) continue;
2332 s = endname = Ustrchr(h->text, ':') + 1;
2334 /* Scan the addresses in the header, enabling group syntax. Note that we
2335 have to reset this after the header has been scanned. */
2337 parse_allow_group = TRUE;
2341 address_item *vaddr;
2343 while (isspace(*s) || *s == ',') s++;
2344 if (*s == 0) break; /* End of header */
2346 ss = parse_find_address_end(s, FALSE);
2348 /* The terminator is a comma or end of header, but there may be white
2349 space preceding it (including newline for the last address). Move back
2350 past any white space so we can check against any cached envelope sender
2351 address verifications. */
2353 while (isspace(ss[-1])) ss--;
2357 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2358 (int)(endname - h->text), h->text, s);
2360 /* See if we have already verified this address as an envelope sender,
2361 and if so, use the previous answer. */
2363 vaddr = verify_checked_sender(s);
2365 if (vaddr != NULL && /* Previously checked */
2366 (callout <= 0 || /* No callout needed; OR */
2367 vaddr->special_action > 256)) /* Callout was done */
2369 new_ok = vaddr->special_action & 255;
2370 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2371 *ss = terminator; /* Restore shortened string */
2374 /* Otherwise we run the verification now. We must restore the shortened
2375 string before running the verification, so the headers are correct, in
2376 case there is any rewriting. */
2380 int start, end, domain;
2381 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2386 /* If we found an empty address, just carry on with the next one, but
2387 kill the message. */
2389 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2396 /* If verification failed because of a syntax error, fail this
2397 function, and ensure that the failing address gets added to the error
2400 if (address == NULL)
2403 while (ss > s && isspace(ss[-1])) ss--;
2404 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2405 "scanning for sender: %s in \"%.*s\"",
2406 endname - h->text, h->text, *log_msgptr, ss - s, s);
2412 /* Else go ahead with the sender verification. But it isn't *the*
2413 sender of the message, so set vopt_fake_sender to stop sender_address
2414 being replaced after rewriting or qualification. */
2418 vaddr = deliver_make_addr(address, FALSE);
2419 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2420 callout, callout_overall, callout_connect, se_mailfrom,
2425 /* We now have the result, either newly found, or cached. If we are
2426 giving out error details, set a specific user error. This means that the
2427 last of these will be returned to the user if all three fail. We do not
2428 set a log message - the generic one below will be used. */
2432 *verrno = vaddr->basic_errno;
2433 if (smtp_return_error_details)
2435 *user_msgptr = string_sprintf("Rejected after DATA: "
2436 "could not verify \"%.*s\" header address\n%s: %s",
2437 endname - h->text, h->text, vaddr->address, vaddr->message);
2441 /* Success or defer */
2450 if (new_ok == DEFER) yield = DEFER;
2452 /* Move on to any more addresses in the header */
2455 } /* Next address */
2457 parse_allow_group = FALSE;
2458 parse_found_group = FALSE;
2459 } /* Next header, unless done */
2460 } /* Next header type unless done */
2462 if (yield == FAIL && *log_msgptr == NULL)
2463 *log_msgptr = US"there is no valid sender in any header line";
2465 if (yield == DEFER && *log_msgptr == NULL)
2466 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2474 /*************************************************
2475 * Get RFC 1413 identification *
2476 *************************************************/
2478 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2479 the timeout is set to zero, then the query is not done. There may also be lists
2480 of hosts and nets which are exempt. To guard against malefactors sending
2481 non-printing characters which could, for example, disrupt a message's headers,
2482 make sure the string consists of printing characters only.
2485 port the port to connect to; usually this is IDENT_PORT (113), but when
2486 running in the test harness with -bh a different value is used.
2490 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2494 verify_get_ident(int port)
2496 int sock, host_af, qlen;
2497 int received_sender_port, received_interface_port, n;
2499 uschar buffer[2048];
2501 /* Default is no ident. Check whether we want to do an ident check for this
2504 sender_ident = NULL;
2505 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2508 DEBUG(D_ident) debug_printf("doing ident callback\n");
2510 /* Set up a connection to the ident port of the remote host. Bind the local end
2511 to the incoming interface address. If the sender host address is an IPv6
2512 address, the incoming interface address will also be IPv6. */
2514 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2515 sock = ip_socket(SOCK_STREAM, host_af);
2516 if (sock < 0) return;
2518 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2520 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2525 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2528 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2530 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2531 sender_host_address);
2535 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2536 sender_host_address, strerror(errno));
2541 /* Construct and send the query. */
2543 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2544 qlen = Ustrlen(buffer);
2545 if (send(sock, buffer, qlen, 0) < 0)
2547 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2551 /* Read a response line. We put it into the rest of the buffer, using several
2552 recv() calls if necessary. */
2560 int size = sizeof(buffer) - (p - buffer);
2562 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2563 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2564 if (count <= 0) goto END_OFF; /* Read error or EOF */
2566 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2567 generous, and accept a plain \n terminator as well. The only illegal
2570 for (pp = p; pp < p + count; pp++)
2572 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2575 if (pp[-1] == '\r') pp--;
2577 goto GOT_DATA; /* Break out of both loops */
2581 /* Reached the end of the data without finding \n. Let the loop continue to
2582 read some more, if there is room. */
2589 /* We have received a line of data. Check it carefully. It must start with the
2590 same two port numbers that we sent, followed by data as defined by the RFC. For
2593 12345 , 25 : USERID : UNIX :root
2595 However, the amount of white space may be different to what we sent. In the
2596 "osname" field there may be several sub-fields, comma separated. The data we
2597 actually want to save follows the third colon. Some systems put leading spaces
2598 in it - we discard those. */
2600 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2601 &received_interface_port, &n) != 2 ||
2602 received_sender_port != sender_host_port ||
2603 received_interface_port != interface_port)
2606 p = buffer + qlen + n;
2607 while(isspace(*p)) p++;
2608 if (*p++ != ':') goto END_OFF;
2609 while(isspace(*p)) p++;
2610 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2612 while(isspace(*p)) p++;
2613 if (*p++ != ':') goto END_OFF;
2614 while (*p != 0 && *p != ':') p++;
2615 if (*p++ == 0) goto END_OFF;
2616 while(isspace(*p)) p++;
2617 if (*p == 0) goto END_OFF;
2619 /* The rest of the line is the data we want. We turn it into printing
2620 characters when we save it, so that it cannot mess up the format of any logging
2621 or Received: lines into which it gets inserted. We keep a maximum of 127
2624 sender_ident = string_printing(string_copyn(p, 127));
2625 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2635 /*************************************************
2636 * Match host to a single host-list item *
2637 *************************************************/
2639 /* This function compares a host (name or address) against a single item
2640 from a host list. The host name gets looked up if it is needed and is not
2641 already known. The function is called from verify_check_this_host() via
2642 match_check_list(), which is why most of its arguments are in a single block.
2645 arg the argument block (see below)
2646 ss the host-list item
2647 valueptr where to pass back looked up data, or NULL
2648 error for error message when returning ERROR
2651 host_name (a) the host name, or
2652 (b) NULL, implying use sender_host_name and
2653 sender_host_aliases, looking them up if required, or
2654 (c) the empty string, meaning that only IP address matches
2656 host_address the host address
2657 host_ipv4 the IPv4 address taken from an IPv6 one
2661 DEFER lookup deferred
2662 ERROR (a) failed to find the host name or IP address, or
2663 (b) unknown lookup type specified, or
2664 (c) host name encountered when only IP addresses are
2669 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2671 check_host_block *cb = (check_host_block *)arg;
2674 BOOL iplookup = FALSE;
2675 BOOL isquery = FALSE;
2676 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2681 /* Optimize for the special case when the pattern is "*". */
2683 if (*ss == '*' && ss[1] == 0) return OK;
2685 /* If the pattern is empty, it matches only in the case when there is no host -
2686 this can occur in ACL checking for SMTP input using the -bs option. In this
2687 situation, the host address is the empty string. */
2689 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2690 if (*ss == 0) return FAIL;
2692 /* If the pattern is precisely "@" then match against the primary host name,
2693 provided that host name matching is permitted; if it's "@[]" match against the
2694 local host's IP addresses. */
2700 if (isiponly) return ERROR;
2701 ss = primary_hostname;
2703 else if (Ustrcmp(ss, "@[]") == 0)
2705 ip_address_item *ip;
2706 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2707 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2712 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2713 a (possibly masked) comparision with the current IP address. */
2715 if (string_is_ip_address(ss, &maskoffset) != 0)
2716 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2718 /* The pattern is not an IP address. A common error that people make is to omit
2719 one component of an IPv4 address, either by accident, or believing that, for
2720 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,
2721 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2722 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2723 ancient specification.) To aid in debugging these cases, we give a specific
2724 error if the pattern contains only digits and dots or contains a slash preceded
2725 only by digits and dots (a slash at the start indicates a file name and of
2726 course slashes may be present in lookups, but not preceded only by digits and
2729 for (t = ss; isdigit(*t) || *t == '.'; t++);
2730 if (*t == 0 || (*t == '/' && t != ss))
2732 *error = US"malformed IPv4 address or address mask";
2736 /* See if there is a semicolon in the pattern */
2738 semicolon = Ustrchr(ss, ';');
2740 /* If we are doing an IP address only match, then all lookups must be IP
2741 address lookups, even if there is no "net-". */
2745 iplookup = semicolon != NULL;
2748 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2749 a lookup on a masked IP network, in textual form. We obey this code even if we
2750 have already set iplookup, so as to skip over the "net-" prefix and to set the
2751 mask length. The net- stuff really only applies to single-key lookups where the
2752 key is implicit. For query-style lookups the key is specified in the query.
2753 From release 4.30, the use of net- for query style is no longer needed, but we
2754 retain it for backward compatibility. */
2756 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2759 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2760 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2761 iplookup = (*t++ == '-');
2765 /* Do the IP address lookup if that is indeed what we have */
2773 uschar *filename, *key, *result;
2776 /* Find the search type */
2778 search_type = search_findtype(t, semicolon - t);
2780 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2781 search_error_message);
2783 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2784 is no file name, and the "key" is just the query. For query-style with a file
2785 name, we have to fish the file off the start of the query. For a single-key
2786 lookup, the key is the current IP address, masked appropriately, and
2787 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2788 dot separators instead of colons, except when the lookup type is "iplsearch".
2791 if (mac_islookup(search_type, lookup_absfilequery))
2793 filename = semicolon + 1;
2795 while (*key != 0 && !isspace(*key)) key++;
2796 filename = string_copyn(filename, key - filename);
2797 while (isspace(*key)) key++;
2799 else if (mac_islookup(search_type, lookup_querystyle))
2802 key = semicolon + 1;
2804 else /* Single-key style */
2806 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2808 insize = host_aton(cb->host_address, incoming);
2809 host_mask(insize, incoming, mlen);
2810 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2812 filename = semicolon + 1;
2815 /* Now do the actual lookup; note that there is no search_close() because
2816 of the caching arrangements. */
2818 handle = search_open(filename, search_type, 0, NULL, NULL);
2819 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2820 search_error_message);
2821 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2822 if (valueptr != NULL) *valueptr = result;
2823 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2826 /* The pattern is not an IP address or network reference of any kind. That is,
2827 it is a host name pattern. If this is an IP only match, there's an error in the
2832 *error = US"cannot match host name in match_ip list";
2836 /* Check the characters of the pattern to see if they comprise only letters,
2837 digits, full stops, and hyphens (the constituents of domain names). Allow
2838 underscores, as they are all too commonly found. Sigh. Also, if
2839 allow_utf8_domains is set, allow top-bit characters. */
2841 for (t = ss; *t != 0; t++)
2842 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2843 (!allow_utf8_domains || *t < 128)) break;
2845 /* If the pattern is a complete domain name, with no fancy characters, look up
2846 its IP address and match against that. Note that a multi-homed host will add
2847 items to the chain. */
2858 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2859 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2862 for (hh = &h; hh != NULL; hh = hh->next)
2864 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2868 if (rc == HOST_FIND_AGAIN) return DEFER;
2869 *error = string_sprintf("failed to find IP address for %s", ss);
2873 /* Almost all subsequent comparisons require the host name, and can be done
2874 using the general string matching function. When this function is called for
2875 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2876 must use sender_host_name and its aliases, looking them up if necessary. */
2878 if (cb->host_name != NULL) /* Explicit host name given */
2879 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2882 /* Host name not given; in principle we need the sender host name and its
2883 aliases. However, for query-style lookups, we do not need the name if the
2884 query does not contain $sender_host_name. From release 4.23, a reference to
2885 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2888 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2891 int partial, affixlen, starflags, id;
2894 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2897 if (id < 0) /* Unknown lookup type */
2899 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2900 search_error_message, ss);
2903 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2908 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2911 case DEFER: return DEFER;
2912 default: return FAIL;
2916 /* Not a query-style lookup; must ensure the host name is present, and then we
2917 do a check on the name and all its aliases. */
2919 if (sender_host_name == NULL)
2921 HDEBUG(D_host_lookup)
2922 debug_printf("sender host name required, to match against %s\n", ss);
2923 if (host_lookup_failed || host_name_lookup() != OK)
2925 *error = string_sprintf("failed to find host name for %s",
2926 sender_host_address);;
2929 host_build_sender_fullhost();
2932 /* Match on the sender host name, using the general matching function */
2934 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2938 case DEFER: return DEFER;
2941 /* If there are aliases, try matching on them. */
2943 aliases = sender_host_aliases;
2944 while (*aliases != NULL)
2946 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2949 case DEFER: return DEFER;
2958 /*************************************************
2959 * Check a specific host matches a host list *
2960 *************************************************/
2962 /* This function is passed a host list containing items in a number of
2963 different formats and the identity of a host. Its job is to determine whether
2964 the given host is in the set of hosts defined by the list. The host name is
2965 passed as a pointer so that it can be looked up if needed and not already
2966 known. This is commonly the case when called from verify_check_host() to check
2967 an incoming connection. When called from elsewhere the host name should usually
2970 This function is now just a front end to match_check_list(), which runs common
2971 code for scanning a list. We pass it the check_host() function to perform a
2975 listptr pointer to the host list
2976 cache_bits pointer to cache for named lists, or NULL
2977 host_name the host name or NULL, implying use sender_host_name and
2978 sender_host_aliases, looking them up if required
2979 host_address the IP address
2980 valueptr if not NULL, data from a lookup is passed back here
2982 Returns: OK if the host is in the defined set
2983 FAIL if the host is not in the defined set,
2984 DEFER if a data lookup deferred (not a host lookup)
2986 If the host name was needed in order to make a comparison, and could not be
2987 determined from the IP address, the result is FAIL unless the item
2988 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2991 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2992 uschar *host_name, uschar *host_address, uschar **valueptr)
2995 unsigned int *local_cache_bits = cache_bits;
2996 uschar *save_host_address = deliver_host_address;
2997 check_host_block cb;
2998 cb.host_name = host_name;
2999 cb.host_address = host_address;
3001 if (valueptr != NULL) *valueptr = NULL;
3003 /* If the host address starts off ::ffff: it is an IPv6 address in
3004 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3007 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3008 host_address + 7 : host_address;
3010 /* During the running of the check, put the IP address into $host_address. In
3011 the case of calls from the smtp transport, it will already be there. However,
3012 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3013 the safe side, any existing setting is preserved, though as I write this
3014 (November 2004) I can't see any cases where it is actually needed. */
3016 deliver_host_address = host_address;
3017 rc = match_check_list(
3018 listptr, /* the list */
3019 0, /* separator character */
3020 &hostlist_anchor, /* anchor pointer */
3021 &local_cache_bits, /* cache pointer */
3022 check_host, /* function for testing */
3023 &cb, /* argument for function */
3024 MCL_HOST, /* type of check */
3025 (host_address == sender_host_address)?
3026 US"host" : host_address, /* text for debugging */
3027 valueptr); /* where to pass back data */
3028 deliver_host_address = save_host_address;
3035 /*************************************************
3036 * Check the remote host matches a list *
3037 *************************************************/
3039 /* This is a front end to verify_check_this_host(), created because checking
3040 the remote host is a common occurrence. With luck, a good compiler will spot
3041 the tail recursion and optimize it. If there's no host address, this is
3042 command-line SMTP input - check against an empty string for the address.
3045 listptr pointer to the host list
3047 Returns: the yield of verify_check_this_host(),
3048 i.e. OK, FAIL, or DEFER
3052 verify_check_host(uschar **listptr)
3054 return verify_check_this_host(listptr, sender_host_cache, NULL,
3055 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3062 /*************************************************
3063 * Invert an IP address *
3064 *************************************************/
3066 /* Originally just used for DNS xBL lists, now also used for the
3067 reverse_ip expansion operator.
3070 buffer where to put the answer
3071 address the address to invert
3075 invert_address(uschar *buffer, uschar *address)
3078 uschar *bptr = buffer;
3080 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3081 to the IPv4 part only. */
3083 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3085 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3088 if (host_aton(address, bin) == 1)
3092 for (i = 0; i < 4; i++)
3094 sprintf(CS bptr, "%d.", x & 255);
3095 while (*bptr) bptr++;
3100 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3101 in any DNS black lists, and the format in which they will be looked up is
3102 unknown. This is just a guess. */
3108 for (j = 3; j >= 0; j--)
3111 for (i = 0; i < 8; i++)
3113 sprintf(CS bptr, "%x.", x & 15);
3114 while (*bptr) bptr++;
3121 /* Remove trailing period -- this is needed so that both arbitrary
3122 dnsbl keydomains and inverted addresses may be combined with the
3123 same format string, "%s.%s" */
3130 /*************************************************
3131 * Perform a single dnsbl lookup *
3132 *************************************************/
3134 /* This function is called from verify_check_dnsbl() below. It is also called
3135 recursively from within itself when domain and domain_txt are different
3136 pointers, in order to get the TXT record from the alternate domain.
3139 domain the outer dnsbl domain
3140 domain_txt alternate domain to lookup TXT record on success; when the
3141 same domain is to be used, domain_txt == domain (that is,
3142 the pointers must be identical, not just the text)
3143 keydomain the current keydomain (for debug message)
3144 prepend subdomain to lookup (like keydomain, but
3145 reversed if IP address)
3146 iplist the list of matching IP addresses, or NULL for "any"
3147 bitmask true if bitmask matching is wanted
3148 match_type condition for 'succeed' result
3149 0 => Any RR in iplist (=)
3150 1 => No RR in iplist (!=)
3151 2 => All RRs in iplist (==)
3152 3 => Some RRs not in iplist (!==)
3153 the two bits are defined as MT_NOT and MT_ALL
3154 defer_return what to return for a defer
3156 Returns: OK if lookup succeeded
3161 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3162 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3168 dnsbl_cache_block *cb;
3169 int old_pool = store_pool;
3170 uschar query[256]; /* DNS domain max length */
3172 /* Construct the specific query domainname */
3174 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3176 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3177 "(ignored): %s...", query);
3181 /* Look for this query in the cache. */
3183 t = tree_search(dnsbl_cache, query);
3185 /* If not cached from a previous lookup, we must do a DNS lookup, and
3186 cache the result in permanent memory. */
3190 store_pool = POOL_PERM;
3192 /* Set up a tree entry to cache the lookup */
3194 t = store_get(sizeof(tree_node) + Ustrlen(query));
3195 Ustrcpy(t->name, query);
3196 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3197 (void)tree_insertnode(&dnsbl_cache, t);
3199 /* Do the DNS loopup . */
3201 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3202 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3203 cb->text_set = FALSE;
3207 /* If the lookup succeeded, cache the RHS address. The code allows for
3208 more than one address - this was for complete generality and the possible
3209 use of A6 records. However, A6 records have been reduced to experimental
3210 status (August 2001) and may die out. So they may never get used at all,
3211 let alone in dnsbl records. However, leave the code here, just in case.
3213 Quite apart from one A6 RR generating multiple addresses, there are DNS
3214 lists that return more than one A record, so we must handle multiple
3215 addresses generated in that way as well. */
3217 if (cb->rc == DNS_SUCCEED)
3220 dns_address **addrp = &(cb->rhs);
3221 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3223 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3225 if (rr->type == T_A)
3227 dns_address *da = dns_address_from_rr(&dnsa, rr);
3231 while (da->next != NULL) da = da->next;
3232 addrp = &(da->next);
3237 /* If we didn't find any A records, change the return code. This can
3238 happen when there is a CNAME record but there are no A records for what
3241 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3244 store_pool = old_pool;
3247 /* Previous lookup was cached */
3251 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3255 /* We now have the result of the DNS lookup, either newly done, or cached
3256 from a previous call. If the lookup succeeded, check against the address
3257 list if there is one. This may be a positive equality list (introduced by
3258 "="), a negative equality list (introduced by "!="), a positive bitmask
3259 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3261 if (cb->rc == DNS_SUCCEED)
3263 dns_address *da = NULL;
3264 uschar *addlist = cb->rhs->address;
3266 /* For A and AAAA records, there may be multiple addresses from multiple
3267 records. For A6 records (currently not expected to be used) there may be
3268 multiple addresses from a single record. */
3270 for (da = cb->rhs->next; da != NULL; da = da->next)
3271 addlist = string_sprintf("%s, %s", addlist, da->address);
3273 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3276 /* Address list check; this can be either for equality, or via a bitmask.
3277 In the latter case, all the bits must match. */
3281 for (da = cb->rhs; da != NULL; da = da->next)
3285 uschar *ptr = iplist;
3288 /* Handle exact matching */
3292 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3294 if (Ustrcmp(CS da->address, ip) == 0) break;
3298 /* Handle bitmask matching */
3305 /* At present, all known DNS blocking lists use A records, with
3306 IPv4 addresses on the RHS encoding the information they return. I
3307 wonder if this will linger on as the last vestige of IPv4 when IPv6
3308 is ubiquitous? Anyway, for now we use paranoia code to completely
3309 ignore IPv6 addresses. The default mask is 0, which always matches.
3310 We change this only for IPv4 addresses in the list. */
3312 if (host_aton(da->address, address) == 1) mask = address[0];
3314 /* Scan the returned addresses, skipping any that are IPv6 */
3316 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3318 if (host_aton(ip, address) != 1) continue;
3319 if ((address[0] & mask) == address[0]) break;
3325 (a) An IP address in an any ('=') list matched, or
3326 (b) No IP address in an all ('==') list matched
3328 then we're done searching. */
3330 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3333 /* If da == NULL, either
3335 (a) No IP address in an any ('=') list matched, or
3336 (b) An IP address in an all ('==') list didn't match
3338 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3341 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3349 res = US"was no match";
3352 res = US"was an exclude match";
3355 res = US"was an IP address that did not match";
3358 res = US"were no IP addresses that did not match";
3361 debug_printf("=> but we are not accepting this block class because\n");
3362 debug_printf("=> there %s for %s%c%s\n",
3364 ((match_type & MT_ALL) == 0)? "" : "=",
3365 bitmask? '&' : '=', iplist);
3371 /* Either there was no IP list, or the record matched, implying that the
3372 domain is on the list. We now want to find a corresponding TXT record. If an
3373 alternate domain is specified for the TXT record, call this function
3374 recursively to look that up; this has the side effect of re-checking that
3375 there is indeed an A record at the alternate domain. */
3377 if (domain_txt != domain)
3378 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3379 FALSE, match_type, defer_return);
3381 /* If there is no alternate domain, look up a TXT record in the main domain
3382 if it has not previously been cached. */
3386 cb->text_set = TRUE;
3387 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3390 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3392 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3393 if (rr->type == T_TXT) break;
3396 int len = (rr->data)[0];
3397 if (len > 511) len = 127;
3398 store_pool = POOL_PERM;
3399 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3400 store_pool = old_pool;
3405 dnslist_value = addlist;
3406 dnslist_text = cb->text;
3410 /* There was a problem with the DNS lookup */
3412 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3414 log_write(L_dnslist_defer, LOG_MAIN,
3415 "DNS list lookup defer (probably timeout) for %s: %s", query,
3416 (defer_return == OK)? US"assumed in list" :
3417 (defer_return == FAIL)? US"assumed not in list" :
3418 US"returned DEFER");
3419 return defer_return;
3422 /* No entry was found in the DNS; continue for next domain */
3426 debug_printf("DNS lookup for %s failed\n", query);
3427 debug_printf("=> that means %s is not listed at %s\n",
3437 /*************************************************
3438 * Check host against DNS black lists *
3439 *************************************************/
3441 /* This function runs checks against a list of DNS black lists, until one
3442 matches. Each item on the list can be of the form
3444 domain=ip-address/key
3446 The domain is the right-most domain that is used for the query, for example,
3447 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3448 if the DNS lookup returns a matching IP address. Several addresses may be
3449 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3451 If no key is given, what is looked up in the domain is the inverted IP address
3452 of the current client host. If a key is given, it is used to construct the
3453 domain for the lookup. For example:
3455 dsn.rfc-ignorant.org/$sender_address_domain
3457 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3458 then we check for a TXT record for an error message, and if found, save its
3459 value in $dnslist_text. We also cache everything in a tree, to optimize
3462 The TXT record is normally looked up in the same domain as the A record, but
3463 when many lists are combined in a single DNS domain, this will not be a very
3464 specific message. It is possible to specify a different domain for looking up
3465 TXT records; this is given before the main domain, comma-separated. For
3468 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3469 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3471 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3473 Note: an address for testing RBL is 192.203.178.39
3474 Note: an address for testing DUL is 192.203.178.4
3475 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3478 listptr the domain/address/data list
3480 Returns: OK successful lookup (i.e. the address is on the list), or
3481 lookup deferred after +include_unknown
3482 FAIL name not found, or no data found for the given type, or
3483 lookup deferred after +exclude_unknown (default)
3484 DEFER lookup failure, if +defer_unknown was set
3488 verify_check_dnsbl(uschar **listptr)
3491 int defer_return = FAIL;
3492 uschar *list = *listptr;
3495 uschar buffer[1024];
3496 uschar revadd[128]; /* Long enough for IPv6 address */
3498 /* Indicate that the inverted IP address is not yet set up */
3502 /* In case this is the first time the DNS resolver is being used. */
3504 dns_init(FALSE, FALSE);
3506 /* Loop through all the domains supplied, until something matches */
3508 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3511 BOOL bitmask = FALSE;
3518 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3520 /* Deal with special values that change the behaviour on defer */
3522 if (domain[0] == '+')
3524 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3525 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3526 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3528 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3533 /* See if there's explicit data to be looked up */
3535 key = Ustrchr(domain, '/');
3536 if (key != NULL) *key++ = 0;
3538 /* See if there's a list of addresses supplied after the domain name. This is
3539 introduced by an = or a & character; if preceded by = we require all matches
3540 and if preceded by ! we invert the result. */
3542 iplist = Ustrchr(domain, '=');
3546 iplist = Ustrchr(domain, '&');
3549 if (iplist != NULL) /* Found either = or & */
3551 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3553 match_type |= MT_NOT;
3557 *iplist++ = 0; /* Terminate domain, move on */
3559 /* If we found = (bitmask == FALSE), check for == or =& */
3561 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3563 bitmask = *iplist++ == '&';
3564 match_type |= MT_ALL;
3568 /* If there is a comma in the domain, it indicates that a second domain for
3569 looking up TXT records is provided, before the main domain. Otherwise we must
3570 set domain_txt == domain. */
3572 domain_txt = domain;
3573 comma = Ustrchr(domain, ',');
3580 /* Check that what we have left is a sensible domain name. There is no reason
3581 why these domains should in fact use the same syntax as hosts and email
3582 domains, but in practice they seem to. However, there is little point in
3583 actually causing an error here, because that would no doubt hold up incoming
3584 mail. Instead, I'll just log it. */
3586 for (s = domain; *s != 0; s++)
3588 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3590 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3591 "strange characters - is this right?", domain);
3596 /* Check the alternate domain if present */
3598 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3600 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3602 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3603 "strange characters - is this right?", domain_txt);
3608 /* If there is no key string, construct the query by adding the domain name
3609 onto the inverted host address, and perform a single DNS lookup. */
3613 if (sender_host_address == NULL) return FAIL; /* can never match */
3614 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3615 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3616 iplist, bitmask, match_type, defer_return);
3619 dnslist_domain = string_copy(domain_txt);
3620 dnslist_matched = string_copy(sender_host_address);
3621 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3622 sender_host_address, dnslist_domain);
3624 if (rc != FAIL) return rc; /* OK or DEFER */
3627 /* If there is a key string, it can be a list of domains or IP addresses to
3628 be concatenated with the main domain. */
3635 uschar keybuffer[256];
3636 uschar keyrevadd[128];
3638 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3639 sizeof(keybuffer))) != NULL)
3641 uschar *prepend = keydomain;
3643 if (string_is_ip_address(keydomain, NULL) != 0)
3645 invert_address(keyrevadd, keydomain);
3646 prepend = keyrevadd;
3649 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3650 bitmask, match_type, defer_return);
3654 dnslist_domain = string_copy(domain_txt);
3655 dnslist_matched = string_copy(keydomain);
3656 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3657 keydomain, dnslist_domain);
3661 /* If the lookup deferred, remember this fact. We keep trying the rest
3662 of the list to see if we get a useful result, and if we don't, we return
3663 DEFER at the end. */
3665 if (rc == DEFER) defer = TRUE;
3666 } /* continue with next keystring domain/address */
3668 if (defer) return DEFER;
3670 } /* continue with next dnsdb outer domain */
3675 /* End of verify.c */