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 /* Precompile some regex that are used to recognize parameters in response
411 to an EHLO command, if they aren't already compiled. */
413 if (regex_STARTTLS == NULL) regex_STARTTLS =
414 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
417 /* Now make connections to the hosts and do real callouts. The list of hosts
418 is passed in as an argument. */
420 for (host = host_list; host != NULL && !done; host = host->next)
422 smtp_inblock inblock;
423 smtp_outblock outblock;
426 BOOL send_quit = TRUE;
427 uschar *active_hostname = smtp_active_hostname;
431 BOOL suppress_tls = FALSE;
432 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
433 uschar inbuffer[4096];
434 uschar outbuffer[1024];
435 uschar responsebuffer[4096];
437 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
438 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
440 /* Skip this host if we don't have an IP address for it. */
442 if (host->address == NULL)
444 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
449 /* Check the overall callout timeout */
451 if (time(NULL) - callout_start_time >= callout_overall)
453 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
457 /* Set IPv4 or IPv6 */
459 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
461 /* Expand and interpret the interface and port strings. The latter will not
462 be used if there is a host-specific port (e.g. from a manualroute router).
463 This has to be delayed till now, because they may expand differently for
464 different hosts. If there's a failure, log it, but carry on with the
467 deliver_host = host->name;
468 deliver_host_address = host->address;
469 deliver_domain = addr->domain;
471 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
473 !smtp_get_port(tf->port, addr, &port, US"callout"))
474 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
477 /* Set HELO string according to the protocol */
478 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
479 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
482 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
484 /* Set up the buffer for reading SMTP response packets. */
486 inblock.buffer = inbuffer;
487 inblock.buffersize = sizeof(inbuffer);
488 inblock.ptr = inbuffer;
489 inblock.ptrend = inbuffer;
491 /* Set up the buffer for holding SMTP commands while pipelining */
493 outblock.buffer = outbuffer;
494 outblock.buffersize = sizeof(outbuffer);
495 outblock.ptr = outbuffer;
496 outblock.cmd_count = 0;
497 outblock.authenticating = FALSE;
499 /* Reset the parameters of a TLS session */
500 tls_out.cipher = tls_out.peerdn = NULL;
502 /* Connect to the host; on failure, just loop for the next one, but we
503 set the error for the last one. Use the callout_connect timeout. */
505 tls_retry_connection:
507 inblock.sock = outblock.sock =
508 smtp_connect(host, host_af, port, interface, callout_connect, TRUE);
509 /* reconsider DSCP here */
510 if (inblock.sock < 0)
512 addr->message = string_sprintf("could not connect to %s [%s]: %s",
513 host->name, host->address, strerror(errno));
514 deliver_host = deliver_host_address = NULL;
515 deliver_domain = save_deliver_domain;
519 /* Expand the helo_data string to find the host name to use. */
521 if (tf->helo_data != NULL)
523 uschar *s = expand_string(tf->helo_data);
525 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
526 "helo_data value for callout: %s", addr->address,
527 expand_string_message);
528 else active_hostname = s;
531 deliver_host = deliver_host_address = NULL;
532 deliver_domain = save_deliver_domain;
534 /* Wait for initial response, and send HELO. The smtp_write_command()
535 function leaves its command in big_buffer. This is used in error responses.
536 Initialize it in case the connection is rejected. */
538 Ustrcpy(big_buffer, "initial connection");
540 /* Unless ssl-on-connect, wait for the initial greeting */
544 if (!smtps || (smtps && tls_out.active >= 0))
546 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
547 goto RESPONSE_FAILED;
549 /* Not worth checking greeting line for ESMTP support */
550 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
551 host->name, host->address, NULL) != OK))
553 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
558 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
561 ob->tls_tempfail_tryclear = FALSE;
563 else /* all other cases */
568 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
569 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
571 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
573 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
576 goto RESPONSE_FAILED;
582 goto esmtp_retry; /* fallback to HELO */
585 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
587 tls_offered = esmtp && !suppress_tls && tls_out.active < 0 &&
588 pcre_exec(regex_STARTTLS, NULL, CS responsebuffer, Ustrlen(responsebuffer), 0,
589 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)
606 uschar buffer2[4096];
608 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
611 /* If there is an I/O error, transmission of this message is deferred. If
612 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
613 false, we also defer. However, if there is a temporary rejection of STARTTLS
614 and tls_tempfail_tryclear is true, or if there is an outright rejection of
615 STARTTLS, we carry on. This means we will try to send the message in clear,
616 unless the host is in hosts_require_tls (tested below). */
618 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
619 ob->command_timeout))
621 if (errno != 0 || buffer2[0] == 0 ||
622 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
624 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
626 goto RESPONSE_FAILED;
630 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
633 int rc = tls_client_start(inblock.sock, host, addr,
634 NULL, /* No DH param */
635 ob->tls_certificate, ob->tls_privatekey,
637 ob->tls_verify_certificates, ob->tls_crl,
638 ob->tls_require_ciphers,
639 ob->gnutls_require_mac, ob->gnutls_require_kx, ob->gnutls_require_proto,
642 /* TLS negotiation failed; give an error. Try in clear on a new connection,
643 if the options permit it for this host. */
646 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
647 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
648 host->address, NULL) != OK)
650 (void)close(inblock.sock);
651 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
652 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
654 goto tls_retry_connection;
656 /*save_errno = ERRNO_TLSFAILURE;*/
657 /*message = US"failure while setting up TLS session";*/
663 /* TLS session is set up. Copy info for logging. */
664 addr->cipher = tls_out.cipher;
665 addr->peerdn = tls_out.peerdn;
667 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
669 goto smtps_redo_greeting;
671 /* For STARTTLS we need to redo EHLO */
676 /* If the host is required to use a secure channel, ensure that we have one. */
677 if (tls_out.active < 0)
678 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
679 host->address, NULL) == OK)
681 /*save_errno = ERRNO_TLSREQUIRED;*/
682 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
683 host->name, host->address,
684 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
689 #endif /*SUPPORT_TLS*/
691 done = TRUE; /* so far so good; have response to HELO */
693 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING, AUTH */
694 /* If we haven't authenticated, but are required to, give up. */
696 /*XXX "filter command specified for this transport" ??? */
697 /* for now, transport_filter by cutthrough-delivery is not supported */
698 /* Need proper integration with the proper transport mechanism. */
705 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
708 /* Failure to accept HELO is cached; this blocks the whole domain for all
709 senders. I/O errors and defer responses are not cached. */
713 *failure_ptr = US"mail"; /* At or before MAIL */
714 if (errno == 0 && responsebuffer[0] == '5')
716 setflag(addr, af_verify_nsfail);
717 new_domain_record.result = ccache_reject;
721 /* Send the MAIL command */
724 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
725 from_address) >= 0 &&
726 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
729 /* If the host does not accept MAIL FROM:<>, arrange to cache this
730 information, but again, don't record anything for an I/O error or a defer. Do
731 not cache rejections of MAIL when a non-empty sender has been used, because
732 that blocks the whole domain for all senders. */
736 *failure_ptr = US"mail"; /* At or before MAIL */
737 if (errno == 0 && responsebuffer[0] == '5')
739 setflag(addr, af_verify_nsfail);
740 if (from_address[0] == 0)
741 new_domain_record.result = ccache_reject_mfnull;
745 /* Otherwise, proceed to check a "random" address (if required), then the
746 given address, and the postmaster address (if required). Between each check,
747 issue RSET, because some servers accept only one recipient after MAIL
750 Before doing this, set the result in the domain cache record to "accept",
751 unless its previous value was ccache_reject_mfnull. In that case, the domain
752 rejects MAIL FROM:<> and we want to continue to remember that. When that is
753 the case, we have got here only in the case of a recipient verification with
754 a non-null sender. */
758 new_domain_record.result =
759 (old_domain_cache_result == ccache_reject_mfnull)?
760 ccache_reject_mfnull: ccache_accept;
762 /* Do the random local part check first */
764 if (random_local_part != NULL)
766 uschar randombuffer[1024];
768 smtp_write_command(&outblock, FALSE,
769 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
770 addr->domain) >= 0 &&
771 smtp_read_response(&inblock, randombuffer,
772 sizeof(randombuffer), '2', callout);
774 /* Remember when we last did a random test */
776 new_domain_record.random_stamp = time(NULL);
778 /* If accepted, we aren't going to do any further tests below. */
782 new_domain_record.random_result = ccache_accept;
785 /* Otherwise, cache a real negative response, and get back to the right
786 state to send RCPT. Unless there's some problem such as a dropped
787 connection, we expect to succeed, because the commands succeeded above. */
791 if (randombuffer[0] == '5')
792 new_domain_record.random_result = ccache_reject;
795 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
796 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
799 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
800 from_address) >= 0 &&
801 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
804 else done = FALSE; /* Some timeout/connection problem */
807 /* If the host is accepting all local parts, as determined by the "random"
808 check, we don't need to waste time doing any further checking. */
810 if (new_domain_record.random_result != ccache_accept && done)
812 /* Get the rcpt_include_affixes flag from the transport if there is one,
813 but assume FALSE if there is not. */
816 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
817 transport_rcpt_address(addr,
818 (addr->transport == NULL)? FALSE :
819 addr->transport->rcpt_include_affixes)) >= 0 &&
820 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
824 new_address_record.result = ccache_accept;
825 else if (errno == 0 && responsebuffer[0] == '5')
827 *failure_ptr = US"recipient";
828 new_address_record.result = ccache_reject;
831 /* Do postmaster check if requested; if a full check is required, we
832 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
834 if (done && pm_mailfrom != NULL)
836 /*XXX not suitable for cutthrough - sequencing problems */
837 cutthrough_delivery= FALSE;
838 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
841 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
842 smtp_read_response(&inblock, responsebuffer,
843 sizeof(responsebuffer), '2', callout) &&
845 smtp_write_command(&outblock, FALSE,
846 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
847 smtp_read_response(&inblock, responsebuffer,
848 sizeof(responsebuffer), '2', callout) &&
850 /* First try using the current domain */
853 smtp_write_command(&outblock, FALSE,
854 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
855 smtp_read_response(&inblock, responsebuffer,
856 sizeof(responsebuffer), '2', callout)
861 /* If that doesn't work, and a full check is requested,
862 try without the domain. */
865 (options & vopt_callout_fullpm) != 0 &&
866 smtp_write_command(&outblock, FALSE,
867 "RCPT TO:<postmaster>\r\n") >= 0 &&
868 smtp_read_response(&inblock, responsebuffer,
869 sizeof(responsebuffer), '2', callout)
872 /* Sort out the cache record */
874 new_domain_record.postmaster_stamp = time(NULL);
877 new_domain_record.postmaster_result = ccache_accept;
878 else if (errno == 0 && responsebuffer[0] == '5')
880 *failure_ptr = US"postmaster";
881 setflag(addr, af_verify_pmfail);
882 new_domain_record.postmaster_result = ccache_reject;
885 } /* Random not accepted */
886 } /* MAIL FROM: accepted */
888 /* For any failure of the main check, other than a negative response, we just
889 close the connection and carry on. We can identify a negative response by the
890 fact that errno is zero. For I/O errors it will be non-zero
892 Set up different error texts for logging and for sending back to the caller
893 as an SMTP response. Log in all cases, using a one-line format. For sender
894 callouts, give a full response to the caller, but for recipient callouts,
895 don't give the IP address because this may be an internal host whose identity
896 is not to be widely broadcast. */
900 if (errno == ETIMEDOUT)
902 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
907 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
910 string_sprintf("response to \"%s\" from %s [%s] was: %s",
911 big_buffer, host->name, host->address,
912 string_printing(responsebuffer));
914 addr->user_message = is_recipient?
915 string_sprintf("Callout verification failed:\n%s", responsebuffer)
917 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
918 host->address, big_buffer, responsebuffer);
920 /* Hard rejection ends the process */
922 if (responsebuffer[0] == '5') /* Address rejected */
930 /* End the SMTP conversation and close the connection. */
932 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
933 and we have no cutthrough conn so far
934 here is where we want to leave the conn open */
935 if ( cutthrough_delivery
938 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
939 && !random_local_part
944 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
945 cutthrough_addr = *addr; /* Save the address_item for later logging */
946 cutthrough_addr.host_used = store_get(sizeof(host_item));
947 cutthrough_addr.host_used->name = host->name;
948 cutthrough_addr.host_used->address = host->address;
949 cutthrough_addr.host_used->port = port;
951 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
952 ctblock.buffer = ctbuffer;
953 ctblock.buffersize = sizeof(ctbuffer);
954 ctblock.ptr = ctbuffer;
955 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
956 ctblock.sock = cutthrough_fd;
960 if (options & vopt_callout_recipsender)
961 cancel_cutthrough_connection(); /* Ensure no cutthrough on multiple address verifies */
962 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
965 tls_close(FALSE, TRUE);
967 (void)close(inblock.sock);
970 } /* Loop through all hosts, while !done */
973 /* If we get here with done == TRUE, a successful callout happened, and yield
974 will be set OK or FAIL according to the response to the RCPT command.
975 Otherwise, we looped through the hosts but couldn't complete the business.
976 However, there may be domain-specific information to cache in both cases.
978 The value of the result field in the new_domain record is ccache_unknown if
979 there was an error before or with MAIL FROM:, and errno was not zero,
980 implying some kind of I/O error. We don't want to write the cache in that case.
981 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
983 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
985 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
988 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
992 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
993 (int)sizeof(dbdata_callout_cache));
994 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
995 " result=%d postmaster=%d random=%d\n",
996 new_domain_record.result,
997 new_domain_record.postmaster_result,
998 new_domain_record.random_result);
1002 /* If a definite result was obtained for the callout, cache it unless caching
1007 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1009 if (dbm_file == NULL)
1010 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1011 if (dbm_file == NULL)
1013 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1017 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1018 (int)sizeof(dbdata_callout_cache_address));
1019 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1020 (new_address_record.result == ccache_accept)? "positive" : "negative");
1025 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1026 temporary error. If there was only one host, and a response was received, leave
1027 it alone if supplying details. Otherwise, give a generic response. */
1031 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1032 is_recipient? "recipient" : "sender");
1035 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1037 addr->user_message = (!smtp_return_error_details)? dullmsg :
1038 string_sprintf("%s for <%s>.\n"
1039 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1040 "they may be permanently unreachable from this server. In the latter case,\n%s",
1041 dullmsg, addr->address,
1043 "the address will never be accepted."
1045 "you need to change the address or create an MX record for its domain\n"
1046 "if it is supposed to be generally accessible from the Internet.\n"
1047 "Talk to your mail administrator for details.");
1049 /* Force a specific error code */
1051 addr->basic_errno = ERRNO_CALLOUTDEFER;
1054 /* Come here from within the cache-reading code on fast-track exit. */
1057 if (dbm_file != NULL) dbfn_close(dbm_file);
1063 /* Called after recipient-acl to get a cutthrough connection open when
1064 one was requested and a recipient-verify wasn't subsequently done.
1067 open_cutthrough_connection( address_item * addr )
1071 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1072 /* We must use a copy of the address for verification, because it might
1076 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1077 (void) verify_address(&addr2, NULL,
1078 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1079 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1081 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1087 /* Send given number of bytes from the buffer */
1089 cutthrough_send(int n)
1091 if(cutthrough_fd < 0)
1096 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1098 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1101 transport_count += n;
1102 ctblock.ptr= ctblock.buffer;
1106 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1113 _cutthrough_puts(uschar * cp, int n)
1117 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1118 if(!cutthrough_send(ctblock.buffersize))
1121 *ctblock.ptr++ = *cp++;
1126 /* Buffered output of counted data block. Return boolean success */
1128 cutthrough_puts(uschar * cp, int n)
1130 if (cutthrough_fd < 0) return TRUE;
1131 if (_cutthrough_puts(cp, n)) return TRUE;
1132 cancel_cutthrough_connection();
1138 _cutthrough_flush_send( void )
1140 int n= ctblock.ptr-ctblock.buffer;
1143 if(!cutthrough_send(n))
1149 /* Send out any bufferred output. Return boolean success. */
1151 cutthrough_flush_send( void )
1153 if (_cutthrough_flush_send()) return TRUE;
1154 cancel_cutthrough_connection();
1160 cutthrough_put_nl( void )
1162 return cutthrough_puts(US"\r\n", 2);
1166 /* Get and check response from cutthrough target */
1168 cutthrough_response(char expect, uschar ** copy)
1170 smtp_inblock inblock;
1171 uschar inbuffer[4096];
1172 uschar responsebuffer[4096];
1174 inblock.buffer = inbuffer;
1175 inblock.buffersize = sizeof(inbuffer);
1176 inblock.ptr = inbuffer;
1177 inblock.ptrend = inbuffer;
1178 inblock.sock = cutthrough_fd;
1179 /* this relies on (inblock.sock == tls_out.active) */
1180 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1181 cancel_cutthrough_connection();
1186 *copy= cp= string_copy(responsebuffer);
1187 /* Trim the trailing end of line */
1188 cp += Ustrlen(responsebuffer);
1189 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1190 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1193 return responsebuffer[0];
1197 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1199 cutthrough_predata( void )
1201 if(cutthrough_fd < 0)
1204 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1205 cutthrough_puts(US"DATA\r\n", 6);
1206 cutthrough_flush_send();
1208 /* Assume nothing buffered. If it was it gets ignored. */
1209 return cutthrough_response('3', NULL) == '3';
1213 /* Buffered send of headers. Return success boolean. */
1214 /* Expands newlines to wire format (CR,NL). */
1215 /* Also sends header-terminating blank line. */
1217 cutthrough_headers_send( void )
1220 uschar * cp1, * cp2;
1222 if(cutthrough_fd < 0)
1225 for(h= header_list; h != NULL; h= h->next)
1226 if(h->type != htype_old && h->text != NULL)
1227 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1228 if( !cutthrough_puts(cp1, cp2-cp1)
1229 || !cutthrough_put_nl())
1232 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1233 return cutthrough_put_nl();
1238 close_cutthrough_connection( void )
1240 if(cutthrough_fd >= 0)
1242 /* We could be sending this after a bunch of data, but that is ok as
1243 the only way to cancel the transfer in dataphase is to drop the tcp
1244 conn before the final dot.
1246 ctblock.ptr = ctbuffer;
1247 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1248 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1249 _cutthrough_flush_send();
1250 /* No wait for response */
1253 tls_close(FALSE, TRUE);
1255 (void)close(cutthrough_fd);
1257 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown ------------\n");
1259 ctblock.ptr = ctbuffer;
1263 cancel_cutthrough_connection( void )
1265 close_cutthrough_connection();
1266 cutthrough_delivery= FALSE;
1272 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1273 Log an OK response as a transmission.
1274 Close the connection.
1275 Return smtp response-class digit.
1278 cutthrough_finaldot( void )
1280 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1282 /* Assume data finshed with new-line */
1283 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1284 return cutthrough_addr.message;
1286 switch(cutthrough_response('2', &cutthrough_addr.message))
1289 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1290 close_cutthrough_connection();
1294 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1298 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1304 return cutthrough_addr.message;
1309 /*************************************************
1310 * Copy error to toplevel address *
1311 *************************************************/
1313 /* This function is used when a verify fails or defers, to ensure that the
1314 failure or defer information is in the original toplevel address. This applies
1315 when an address is redirected to a single new address, and the failure or
1316 deferral happens to the child address.
1319 vaddr the verify address item
1320 addr the final address item
1323 Returns: the value of YIELD
1327 copy_error(address_item *vaddr, address_item *addr, int yield)
1331 vaddr->message = addr->message;
1332 vaddr->user_message = addr->user_message;
1333 vaddr->basic_errno = addr->basic_errno;
1334 vaddr->more_errno = addr->more_errno;
1335 vaddr->p.address_data = addr->p.address_data;
1336 copyflag(vaddr, addr, af_pass_message);
1344 /**************************************************
1345 * printf that automatically handles TLS if needed *
1346 ***************************************************/
1348 /* This function is used by verify_address() as a substitute for all fprintf()
1349 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1350 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1351 that assumes that we always use the smtp_out FILE* when not using TLS or the
1352 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1353 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1357 f the candidate FILE* to write to
1358 format format string
1359 ... optional arguments
1365 static void PRINTF_FUNCTION(2,3)
1366 respond_printf(FILE *f, const char *format, ...)
1370 va_start(ap, format);
1371 if (smtp_out && (f == smtp_out))
1372 smtp_vprintf(format, ap);
1374 vfprintf(f, format, ap);
1380 /*************************************************
1381 * Verify an email address *
1382 *************************************************/
1384 /* This function is used both for verification (-bv and at other times) and
1385 address testing (-bt), which is indicated by address_test_mode being set.
1388 vaddr contains the address to verify; the next field in this block
1390 f if not NULL, write the result to this file
1391 options various option bits:
1392 vopt_fake_sender => this sender verify is not for the real
1393 sender (it was verify=sender=xxxx or an address from a
1394 header line) - rewriting must not change sender_address
1395 vopt_is_recipient => this is a recipient address, otherwise
1396 it's a sender address - this affects qualification and
1397 rewriting and messages from callouts
1398 vopt_qualify => qualify an unqualified address; else error
1399 vopt_expn => called from SMTP EXPN command
1400 vopt_success_on_redirect => when a new address is generated
1401 the verification instantly succeeds
1403 These ones are used by do_callout() -- the options variable
1406 vopt_callout_fullpm => if postmaster check, do full one
1407 vopt_callout_no_cache => don't use callout cache
1408 vopt_callout_random => do the "random" thing
1409 vopt_callout_recipsender => use real sender for recipient
1410 vopt_callout_recippmaster => use postmaster for recipient
1412 callout if > 0, specifies that callout is required, and gives timeout
1413 for individual commands
1414 callout_overall if > 0, gives overall timeout for the callout function;
1415 if < 0, a default is used (see do_callout())
1416 callout_connect the connection timeout for callouts
1417 se_mailfrom when callout is requested to verify a sender, use this
1418 in MAIL FROM; NULL => ""
1419 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1420 thing and use this as the sender address (may be "")
1422 routed if not NULL, set TRUE if routing succeeded, so we can
1423 distinguish between routing failed and callout failed
1425 Returns: OK address verified
1426 FAIL address failed to verify
1427 DEFER can't tell at present
1431 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1432 int callout_overall, int callout_connect, uschar *se_mailfrom,
1433 uschar *pm_mailfrom, BOOL *routed)
1436 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1437 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1438 BOOL expn = (options & vopt_expn) != 0;
1439 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1442 int verify_type = expn? v_expn :
1443 address_test_mode? v_none :
1444 is_recipient? v_recipient : v_sender;
1445 address_item *addr_list;
1446 address_item *addr_new = NULL;
1447 address_item *addr_remote = NULL;
1448 address_item *addr_local = NULL;
1449 address_item *addr_succeed = NULL;
1450 uschar **failure_ptr = is_recipient?
1451 &recipient_verify_failure : &sender_verify_failure;
1452 uschar *ko_prefix, *cr;
1453 uschar *address = vaddr->address;
1454 uschar *save_sender;
1455 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1457 /* Clear, just in case */
1459 *failure_ptr = NULL;
1461 /* Set up a prefix and suffix for error message which allow us to use the same
1462 output statements both in EXPN mode (where an SMTP response is needed) and when
1463 debugging with an output file. */
1467 ko_prefix = US"553 ";
1470 else ko_prefix = cr = US"";
1472 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1474 if (parse_find_at(address) == NULL)
1476 if ((options & vopt_qualify) == 0)
1479 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1480 ko_prefix, address, cr);
1481 *failure_ptr = US"qualify";
1484 address = rewrite_address_qualify(address, is_recipient);
1489 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1490 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1493 /* Rewrite and report on it. Clear the domain and local part caches - these
1494 may have been set by domains and local part tests during an ACL. */
1496 if (global_rewrite_rules != NULL)
1498 uschar *old = address;
1499 address = rewrite_address(address, is_recipient, FALSE,
1500 global_rewrite_rules, rewrite_existflags);
1503 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1504 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1505 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1509 /* If this is the real sender address, we must update sender_address at
1510 this point, because it may be referred to in the routers. */
1512 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1513 sender_address = address;
1515 /* If the address was rewritten to <> no verification can be done, and we have
1516 to return OK. This rewriting is permitted only for sender addresses; for other
1517 addresses, such rewriting fails. */
1519 if (address[0] == 0) return OK;
1521 /* Save a copy of the sender address for re-instating if we change it to <>
1522 while verifying a sender address (a nice bit of self-reference there). */
1524 save_sender = sender_address;
1526 /* Update the address structure with the possibly qualified and rewritten
1527 address. Set it up as the starting address on the chain of new addresses. */
1529 vaddr->address = address;
1532 /* We need a loop, because an address can generate new addresses. We must also
1533 cope with generated pipes and files at the top level. (See also the code and
1534 comment in deliver.c.) However, it is usually the case that the router for
1535 user's .forward files has its verify flag turned off.
1537 If an address generates more than one child, the loop is used only when
1538 full_info is set, and this can only be set locally. Remote enquiries just get
1539 information about the top level address, not anything that it generated. */
1541 while (addr_new != NULL)
1544 address_item *addr = addr_new;
1546 addr_new = addr->next;
1551 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1552 debug_printf("Considering %s\n", addr->address);
1555 /* Handle generated pipe, file or reply addresses. We don't get these
1556 when handling EXPN, as it does only one level of expansion. */
1558 if (testflag(addr, af_pfr))
1565 if (addr->address[0] == '>')
1567 allow = testflag(addr, af_allow_reply);
1568 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1572 allow = (addr->address[0] == '|')?
1573 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1574 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1577 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1578 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1579 "%s\n", addr->message);
1581 fprintf(f, "\n transport = %s\n", addr->transport->name);
1583 fprintf(f, " *** forbidden ***\n");
1588 /* Just in case some router parameter refers to it. */
1590 return_path = (addr->p.errors_address != NULL)?
1591 addr->p.errors_address : sender_address;
1593 /* Split the address into domain and local part, handling the %-hack if
1594 necessary, and then route it. While routing a sender address, set
1595 $sender_address to <> because that is what it will be if we were trying to
1596 send a bounce to the sender. */
1598 if (routed != NULL) *routed = FALSE;
1599 if ((rc = deliver_split_address(addr)) == OK)
1601 if (!is_recipient) sender_address = null_sender;
1602 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1603 &addr_succeed, verify_type);
1604 sender_address = save_sender; /* Put back the real sender */
1607 /* If routing an address succeeded, set the flag that remembers, for use when
1608 an ACL cached a sender verify (in case a callout fails). Then if routing set
1609 up a list of hosts or the transport has a host list, and the callout option
1610 is set, and we aren't in a host checking run, do the callout verification,
1611 and set another flag that notes that a callout happened. */
1615 if (routed != NULL) *routed = TRUE;
1618 host_item *host_list = addr->host_list;
1620 /* Make up some data for use in the case where there is no remote
1623 transport_feedback tf = {
1624 NULL, /* interface (=> any) */
1625 US"smtp", /* port */
1626 US"smtp", /* protocol */
1628 US"$smtp_active_hostname", /* helo_data */
1629 FALSE, /* hosts_override */
1630 FALSE, /* hosts_randomize */
1631 FALSE, /* gethostbyname */
1632 TRUE, /* qualify_single */
1633 FALSE /* search_parents */
1636 /* If verification yielded a remote transport, we want to use that
1637 transport's options, so as to mimic what would happen if we were really
1638 sending a message to this address. */
1640 if (addr->transport != NULL && !addr->transport->info->local)
1642 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1644 /* If the transport has hosts and the router does not, or if the
1645 transport is configured to override the router's hosts, we must build a
1646 host list of the transport's hosts, and find the IP addresses */
1648 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1651 uschar *save_deliver_domain = deliver_domain;
1652 uschar *save_deliver_localpart = deliver_localpart;
1654 host_list = NULL; /* Ignore the router's hosts */
1656 deliver_domain = addr->domain;
1657 deliver_localpart = addr->local_part;
1658 s = expand_string(tf.hosts);
1659 deliver_domain = save_deliver_domain;
1660 deliver_localpart = save_deliver_localpart;
1664 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1665 "\"%s\" in %s transport for callout: %s", tf.hosts,
1666 addr->transport->name, expand_string_message);
1671 uschar *canonical_name;
1672 host_item *host, *nexthost;
1673 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1675 /* Just ignore failures to find a host address. If we don't manage
1676 to find any addresses, the callout will defer. Note that more than
1677 one address may be found for a single host, which will result in
1678 additional host items being inserted into the chain. Hence we must
1679 save the next host first. */
1681 flags = HOST_FIND_BY_A;
1682 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1683 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1685 for (host = host_list; host != NULL; host = nexthost)
1687 nexthost = host->next;
1688 if (tf.gethostbyname ||
1689 string_is_ip_address(host->name, NULL) != 0)
1690 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1692 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1693 &canonical_name, NULL);
1699 /* Can only do a callout if we have at least one host! If the callout
1700 fails, it will have set ${sender,recipient}_verify_failure. */
1702 if (host_list != NULL)
1704 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1705 if (host_checking && !host_checking_callout)
1708 debug_printf("... callout omitted by default when host testing\n"
1709 "(Use -bhc if you want the callouts to happen.)\n");
1713 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1714 callout_connect, options, se_mailfrom, pm_mailfrom);
1719 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1720 "transport provided a host list\n");
1725 /* Otherwise, any failure is a routing failure */
1727 else *failure_ptr = US"route";
1729 /* A router may return REROUTED if it has set up a child address as a result
1730 of a change of domain name (typically from widening). In this case we always
1731 want to continue to verify the new child. */
1733 if (rc == REROUTED) continue;
1735 /* Handle hard failures */
1742 address_item *p = addr->parent;
1744 respond_printf(f, "%s%s %s", ko_prefix,
1745 full_info? addr->address : address,
1746 address_test_mode? "is undeliverable" : "failed to verify");
1747 if (!expn && admin_user)
1749 if (addr->basic_errno > 0)
1750 respond_printf(f, ": %s", strerror(addr->basic_errno));
1751 if (addr->message != NULL)
1752 respond_printf(f, ": %s", addr->message);
1755 /* Show parents iff doing full info */
1757 if (full_info) while (p != NULL)
1759 respond_printf(f, "%s\n <-- %s", cr, p->address);
1762 respond_printf(f, "%s\n", cr);
1764 cancel_cutthrough_connection();
1766 if (!full_info) return copy_error(vaddr, addr, FAIL);
1772 else if (rc == DEFER)
1777 address_item *p = addr->parent;
1778 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1779 full_info? addr->address : address);
1780 if (!expn && admin_user)
1782 if (addr->basic_errno > 0)
1783 respond_printf(f, ": %s", strerror(addr->basic_errno));
1784 if (addr->message != NULL)
1785 respond_printf(f, ": %s", addr->message);
1786 else if (addr->basic_errno <= 0)
1787 respond_printf(f, ": unknown error");
1790 /* Show parents iff doing full info */
1792 if (full_info) while (p != NULL)
1794 respond_printf(f, "%s\n <-- %s", cr, p->address);
1797 respond_printf(f, "%s\n", cr);
1799 cancel_cutthrough_connection();
1801 if (!full_info) return copy_error(vaddr, addr, DEFER);
1802 else if (yield == OK) yield = DEFER;
1805 /* If we are handling EXPN, we do not want to continue to route beyond
1806 the top level (whose address is in "address"). */
1810 uschar *ok_prefix = US"250-";
1811 if (addr_new == NULL)
1813 if (addr_local == NULL && addr_remote == NULL)
1814 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1816 respond_printf(f, "250 <%s>\r\n", address);
1818 else while (addr_new != NULL)
1820 address_item *addr2 = addr_new;
1821 addr_new = addr2->next;
1822 if (addr_new == NULL) ok_prefix = US"250 ";
1823 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1828 /* Successful routing other than EXPN. */
1832 /* Handle successful routing when short info wanted. Otherwise continue for
1833 other (generated) addresses. Short info is the operational case. Full info
1834 can be requested only when debug_selector != 0 and a file is supplied.
1836 There is a conflict between the use of aliasing as an alternate email
1837 address, and as a sort of mailing list. If an alias turns the incoming
1838 address into just one address (e.g. J.Caesar->jc44) you may well want to
1839 carry on verifying the generated address to ensure it is valid when
1840 checking incoming mail. If aliasing generates multiple addresses, you
1841 probably don't want to do this. Exim therefore treats the generation of
1842 just a single new address as a special case, and continues on to verify the
1843 generated address. */
1845 if (!full_info && /* Stop if short info wanted AND */
1846 (((addr_new == NULL || /* No new address OR */
1847 addr_new->next != NULL || /* More than one new address OR */
1848 testflag(addr_new, af_pfr))) /* New address is pfr */
1850 (addr_new != NULL && /* At least one new address AND */
1851 success_on_redirect))) /* success_on_redirect is set */
1853 if (f != NULL) fprintf(f, "%s %s\n", address,
1854 address_test_mode? "is deliverable" : "verified");
1856 /* If we have carried on to verify a child address, we want the value
1857 of $address_data to be that of the child */
1859 vaddr->p.address_data = addr->p.address_data;
1863 } /* Loop for generated addresses */
1865 /* Display the full results of the successful routing, including any generated
1866 addresses. Control gets here only when full_info is set, which requires f not
1867 to be NULL, and this occurs only when a top-level verify is called with the
1868 debugging switch on.
1870 If there are no local and no remote addresses, and there were no pipes, files,
1871 or autoreplies, and there were no errors or deferments, the message is to be
1872 discarded, usually because of the use of :blackhole: in an alias file. */
1874 if (allok && addr_local == NULL && addr_remote == NULL)
1876 fprintf(f, "mail to %s is discarded\n", address);
1880 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1882 while (addr_list != NULL)
1884 address_item *addr = addr_list;
1885 address_item *p = addr->parent;
1886 addr_list = addr->next;
1888 fprintf(f, "%s", CS addr->address);
1889 #ifdef EXPERIMENTAL_SRS
1890 if(addr->p.srs_sender)
1891 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1894 /* If the address is a duplicate, show something about it. */
1896 if (!testflag(addr, af_pfr))
1899 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1900 fprintf(f, " [duplicate, would not be delivered]");
1901 else tree_add_duplicate(addr->unique, addr);
1904 /* Now show its parents */
1908 fprintf(f, "\n <-- %s", p->address);
1913 /* Show router, and transport */
1915 fprintf(f, "router = %s, ", addr->router->name);
1916 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1917 addr->transport->name);
1919 /* Show any hosts that are set up by a router unless the transport
1920 is going to override them; fiddle a bit to get a nice format. */
1922 if (addr->host_list != NULL && addr->transport != NULL &&
1923 !addr->transport->overrides_hosts)
1928 for (h = addr->host_list; h != NULL; h = h->next)
1930 int len = Ustrlen(h->name);
1931 if (len > maxlen) maxlen = len;
1932 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1933 if (len > maxaddlen) maxaddlen = len;
1935 for (h = addr->host_list; h != NULL; h = h->next)
1937 int len = Ustrlen(h->name);
1938 fprintf(f, " host %s ", h->name);
1939 while (len++ < maxlen) fprintf(f, " ");
1940 if (h->address != NULL)
1942 fprintf(f, "[%s] ", h->address);
1943 len = Ustrlen(h->address);
1945 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1947 fprintf(f, "[unknown] ");
1951 while (len++ < maxaddlen) fprintf(f," ");
1952 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1953 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1954 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1961 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1962 the -bv or -bt case). */
1970 /*************************************************
1971 * Check headers for syntax errors *
1972 *************************************************/
1974 /* This function checks those header lines that contain addresses, and verifies
1975 that all the addresses therein are syntactially correct.
1978 msgptr where to put an error message
1985 verify_check_headers(uschar **msgptr)
1991 for (h = header_list; h != NULL && yield == OK; h = h->next)
1993 if (h->type != htype_from &&
1994 h->type != htype_reply_to &&
1995 h->type != htype_sender &&
1996 h->type != htype_to &&
1997 h->type != htype_cc &&
1998 h->type != htype_bcc)
2001 colon = Ustrchr(h->text, ':');
2003 while (isspace(*s)) s++;
2005 /* Loop for multiple addresses in the header, enabling group syntax. Note
2006 that we have to reset this after the header has been scanned. */
2008 parse_allow_group = TRUE;
2012 uschar *ss = parse_find_address_end(s, FALSE);
2013 uschar *recipient, *errmess;
2014 int terminator = *ss;
2015 int start, end, domain;
2017 /* Temporarily terminate the string at this point, and extract the
2018 operative address within, allowing group syntax. */
2021 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2024 /* Permit an unqualified address only if the message is local, or if the
2025 sending host is configured to be permitted to send them. */
2027 if (recipient != NULL && domain == 0)
2029 if (h->type == htype_from || h->type == htype_sender)
2031 if (!allow_unqualified_sender) recipient = NULL;
2035 if (!allow_unqualified_recipient) recipient = NULL;
2037 if (recipient == NULL) errmess = US"unqualified address not permitted";
2040 /* It's an error if no address could be extracted, except for the special
2041 case of an empty address. */
2043 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2045 uschar *verb = US"is";
2050 /* Arrange not to include any white space at the end in the
2051 error message or the header name. */
2053 while (t > s && isspace(t[-1])) t--;
2054 while (tt > h->text && isspace(tt[-1])) tt--;
2056 /* Add the address that failed to the error message, since in a
2057 header with very many addresses it is sometimes hard to spot
2058 which one is at fault. However, limit the amount of address to
2059 quote - cases have been seen where, for example, a missing double
2060 quote in a humungous To: header creates an "address" that is longer
2061 than string_sprintf can handle. */
2070 *msgptr = string_printing(
2071 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2072 errmess, tt - h->text, h->text, verb, len, s));
2075 break; /* Out of address loop */
2078 /* Advance to the next address */
2080 s = ss + (terminator? 1:0);
2081 while (isspace(*s)) s++;
2082 } /* Next address */
2084 parse_allow_group = FALSE;
2085 parse_found_group = FALSE;
2086 } /* Next header unless yield has been set FALSE */
2093 /*************************************************
2094 * Check for blind recipients *
2095 *************************************************/
2097 /* This function checks that every (envelope) recipient is mentioned in either
2098 the To: or Cc: header lines, thus detecting blind carbon copies.
2100 There are two ways of scanning that could be used: either scan the header lines
2101 and tick off the recipients, or scan the recipients and check the header lines.
2102 The original proposed patch did the former, but I have chosen to do the latter,
2103 because (a) it requires no memory and (b) will use fewer resources when there
2104 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2107 Returns: OK if there are no blind recipients
2108 FAIL if there is at least one blind recipient
2112 verify_check_notblind(void)
2115 for (i = 0; i < recipients_count; i++)
2119 uschar *address = recipients_list[i].address;
2121 for (h = header_list; !found && h != NULL; h = h->next)
2125 if (h->type != htype_to && h->type != htype_cc) continue;
2127 colon = Ustrchr(h->text, ':');
2129 while (isspace(*s)) s++;
2131 /* Loop for multiple addresses in the header, enabling group syntax. Note
2132 that we have to reset this after the header has been scanned. */
2134 parse_allow_group = TRUE;
2138 uschar *ss = parse_find_address_end(s, FALSE);
2139 uschar *recipient,*errmess;
2140 int terminator = *ss;
2141 int start, end, domain;
2143 /* Temporarily terminate the string at this point, and extract the
2144 operative address within, allowing group syntax. */
2147 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2150 /* If we found a valid recipient that has a domain, compare it with the
2151 envelope recipient. Local parts are compared case-sensitively, domains
2152 case-insensitively. By comparing from the start with length "domain", we
2153 include the "@" at the end, which ensures that we are comparing the whole
2154 local part of each address. */
2156 if (recipient != NULL && domain != 0)
2158 found = Ustrncmp(recipient, address, domain) == 0 &&
2159 strcmpic(recipient + domain, address + domain) == 0;
2163 /* Advance to the next address */
2165 s = ss + (terminator? 1:0);
2166 while (isspace(*s)) s++;
2167 } /* Next address */
2169 parse_allow_group = FALSE;
2170 parse_found_group = FALSE;
2171 } /* Next header (if found is false) */
2173 if (!found) return FAIL;
2174 } /* Next recipient */
2181 /*************************************************
2182 * Find if verified sender *
2183 *************************************************/
2185 /* Usually, just a single address is verified as the sender of the message.
2186 However, Exim can be made to verify other addresses as well (often related in
2187 some way), and this is useful in some environments. There may therefore be a
2188 chain of such addresses that have previously been tested. This function finds
2189 whether a given address is on the chain.
2191 Arguments: the address to be verified
2192 Returns: pointer to an address item, or NULL
2196 verify_checked_sender(uschar *sender)
2199 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2200 if (Ustrcmp(sender, addr->address) == 0) break;
2208 /*************************************************
2209 * Get valid header address *
2210 *************************************************/
2212 /* Scan the originator headers of the message, looking for an address that
2213 verifies successfully. RFC 822 says:
2215 o The "Sender" field mailbox should be sent notices of
2216 any problems in transport or delivery of the original
2217 messages. If there is no "Sender" field, then the
2218 "From" field mailbox should be used.
2220 o If the "Reply-To" field exists, then the reply should
2221 go to the addresses indicated in that field and not to
2222 the address(es) indicated in the "From" field.
2224 So we check a Sender field if there is one, else a Reply_to field, else a From
2225 field. As some strange messages may have more than one of these fields,
2226 especially if they are resent- fields, check all of them if there is more than
2230 user_msgptr points to where to put a user error message
2231 log_msgptr points to where to put a log error message
2232 callout timeout for callout check (passed to verify_address())
2233 callout_overall overall callout timeout (ditto)
2234 callout_connect connect callout timeout (ditto)
2235 se_mailfrom mailfrom for verify; NULL => ""
2236 pm_mailfrom sender for pm callout check (passed to verify_address())
2237 options callout options (passed to verify_address())
2238 verrno where to put the address basic_errno
2240 If log_msgptr is set to something without setting user_msgptr, the caller
2241 normally uses log_msgptr for both things.
2243 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2244 FAIL is given if no appropriate headers are found
2248 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2249 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2250 uschar *pm_mailfrom, int options, int *verrno)
2252 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2257 for (i = 0; i < 3 && !done; i++)
2260 for (h = header_list; h != NULL && !done; h = h->next)
2262 int terminator, new_ok;
2263 uschar *s, *ss, *endname;
2265 if (h->type != header_types[i]) continue;
2266 s = endname = Ustrchr(h->text, ':') + 1;
2268 /* Scan the addresses in the header, enabling group syntax. Note that we
2269 have to reset this after the header has been scanned. */
2271 parse_allow_group = TRUE;
2275 address_item *vaddr;
2277 while (isspace(*s) || *s == ',') s++;
2278 if (*s == 0) break; /* End of header */
2280 ss = parse_find_address_end(s, FALSE);
2282 /* The terminator is a comma or end of header, but there may be white
2283 space preceding it (including newline for the last address). Move back
2284 past any white space so we can check against any cached envelope sender
2285 address verifications. */
2287 while (isspace(ss[-1])) ss--;
2291 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2292 (int)(endname - h->text), h->text, s);
2294 /* See if we have already verified this address as an envelope sender,
2295 and if so, use the previous answer. */
2297 vaddr = verify_checked_sender(s);
2299 if (vaddr != NULL && /* Previously checked */
2300 (callout <= 0 || /* No callout needed; OR */
2301 vaddr->special_action > 256)) /* Callout was done */
2303 new_ok = vaddr->special_action & 255;
2304 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2305 *ss = terminator; /* Restore shortened string */
2308 /* Otherwise we run the verification now. We must restore the shortened
2309 string before running the verification, so the headers are correct, in
2310 case there is any rewriting. */
2314 int start, end, domain;
2315 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2320 /* If we found an empty address, just carry on with the next one, but
2321 kill the message. */
2323 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2330 /* If verification failed because of a syntax error, fail this
2331 function, and ensure that the failing address gets added to the error
2334 if (address == NULL)
2337 while (ss > s && isspace(ss[-1])) ss--;
2338 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2339 "scanning for sender: %s in \"%.*s\"",
2340 endname - h->text, h->text, *log_msgptr, ss - s, s);
2346 /* Else go ahead with the sender verification. But it isn't *the*
2347 sender of the message, so set vopt_fake_sender to stop sender_address
2348 being replaced after rewriting or qualification. */
2352 vaddr = deliver_make_addr(address, FALSE);
2353 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2354 callout, callout_overall, callout_connect, se_mailfrom,
2359 /* We now have the result, either newly found, or cached. If we are
2360 giving out error details, set a specific user error. This means that the
2361 last of these will be returned to the user if all three fail. We do not
2362 set a log message - the generic one below will be used. */
2366 *verrno = vaddr->basic_errno;
2367 if (smtp_return_error_details)
2369 *user_msgptr = string_sprintf("Rejected after DATA: "
2370 "could not verify \"%.*s\" header address\n%s: %s",
2371 endname - h->text, h->text, vaddr->address, vaddr->message);
2375 /* Success or defer */
2384 if (new_ok == DEFER) yield = DEFER;
2386 /* Move on to any more addresses in the header */
2389 } /* Next address */
2391 parse_allow_group = FALSE;
2392 parse_found_group = FALSE;
2393 } /* Next header, unless done */
2394 } /* Next header type unless done */
2396 if (yield == FAIL && *log_msgptr == NULL)
2397 *log_msgptr = US"there is no valid sender in any header line";
2399 if (yield == DEFER && *log_msgptr == NULL)
2400 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2408 /*************************************************
2409 * Get RFC 1413 identification *
2410 *************************************************/
2412 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2413 the timeout is set to zero, then the query is not done. There may also be lists
2414 of hosts and nets which are exempt. To guard against malefactors sending
2415 non-printing characters which could, for example, disrupt a message's headers,
2416 make sure the string consists of printing characters only.
2419 port the port to connect to; usually this is IDENT_PORT (113), but when
2420 running in the test harness with -bh a different value is used.
2424 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2428 verify_get_ident(int port)
2430 int sock, host_af, qlen;
2431 int received_sender_port, received_interface_port, n;
2433 uschar buffer[2048];
2435 /* Default is no ident. Check whether we want to do an ident check for this
2438 sender_ident = NULL;
2439 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2442 DEBUG(D_ident) debug_printf("doing ident callback\n");
2444 /* Set up a connection to the ident port of the remote host. Bind the local end
2445 to the incoming interface address. If the sender host address is an IPv6
2446 address, the incoming interface address will also be IPv6. */
2448 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2449 sock = ip_socket(SOCK_STREAM, host_af);
2450 if (sock < 0) return;
2452 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2454 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2459 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2462 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2464 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2465 sender_host_address);
2469 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2470 sender_host_address, strerror(errno));
2475 /* Construct and send the query. */
2477 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2478 qlen = Ustrlen(buffer);
2479 if (send(sock, buffer, qlen, 0) < 0)
2481 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2485 /* Read a response line. We put it into the rest of the buffer, using several
2486 recv() calls if necessary. */
2494 int size = sizeof(buffer) - (p - buffer);
2496 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2497 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2498 if (count <= 0) goto END_OFF; /* Read error or EOF */
2500 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2501 generous, and accept a plain \n terminator as well. The only illegal
2504 for (pp = p; pp < p + count; pp++)
2506 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2509 if (pp[-1] == '\r') pp--;
2511 goto GOT_DATA; /* Break out of both loops */
2515 /* Reached the end of the data without finding \n. Let the loop continue to
2516 read some more, if there is room. */
2523 /* We have received a line of data. Check it carefully. It must start with the
2524 same two port numbers that we sent, followed by data as defined by the RFC. For
2527 12345 , 25 : USERID : UNIX :root
2529 However, the amount of white space may be different to what we sent. In the
2530 "osname" field there may be several sub-fields, comma separated. The data we
2531 actually want to save follows the third colon. Some systems put leading spaces
2532 in it - we discard those. */
2534 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2535 &received_interface_port, &n) != 2 ||
2536 received_sender_port != sender_host_port ||
2537 received_interface_port != interface_port)
2540 p = buffer + qlen + n;
2541 while(isspace(*p)) p++;
2542 if (*p++ != ':') goto END_OFF;
2543 while(isspace(*p)) p++;
2544 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2546 while(isspace(*p)) p++;
2547 if (*p++ != ':') goto END_OFF;
2548 while (*p != 0 && *p != ':') p++;
2549 if (*p++ == 0) goto END_OFF;
2550 while(isspace(*p)) p++;
2551 if (*p == 0) goto END_OFF;
2553 /* The rest of the line is the data we want. We turn it into printing
2554 characters when we save it, so that it cannot mess up the format of any logging
2555 or Received: lines into which it gets inserted. We keep a maximum of 127
2558 sender_ident = string_printing(string_copyn(p, 127));
2559 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2569 /*************************************************
2570 * Match host to a single host-list item *
2571 *************************************************/
2573 /* This function compares a host (name or address) against a single item
2574 from a host list. The host name gets looked up if it is needed and is not
2575 already known. The function is called from verify_check_this_host() via
2576 match_check_list(), which is why most of its arguments are in a single block.
2579 arg the argument block (see below)
2580 ss the host-list item
2581 valueptr where to pass back looked up data, or NULL
2582 error for error message when returning ERROR
2585 host_name (a) the host name, or
2586 (b) NULL, implying use sender_host_name and
2587 sender_host_aliases, looking them up if required, or
2588 (c) the empty string, meaning that only IP address matches
2590 host_address the host address
2591 host_ipv4 the IPv4 address taken from an IPv6 one
2595 DEFER lookup deferred
2596 ERROR (a) failed to find the host name or IP address, or
2597 (b) unknown lookup type specified, or
2598 (c) host name encountered when only IP addresses are
2603 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2605 check_host_block *cb = (check_host_block *)arg;
2608 BOOL iplookup = FALSE;
2609 BOOL isquery = FALSE;
2610 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2615 /* Optimize for the special case when the pattern is "*". */
2617 if (*ss == '*' && ss[1] == 0) return OK;
2619 /* If the pattern is empty, it matches only in the case when there is no host -
2620 this can occur in ACL checking for SMTP input using the -bs option. In this
2621 situation, the host address is the empty string. */
2623 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2624 if (*ss == 0) return FAIL;
2626 /* If the pattern is precisely "@" then match against the primary host name,
2627 provided that host name matching is permitted; if it's "@[]" match against the
2628 local host's IP addresses. */
2634 if (isiponly) return ERROR;
2635 ss = primary_hostname;
2637 else if (Ustrcmp(ss, "@[]") == 0)
2639 ip_address_item *ip;
2640 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2641 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2646 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2647 a (possibly masked) comparision with the current IP address. */
2649 if (string_is_ip_address(ss, &maskoffset) != 0)
2650 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2652 /* The pattern is not an IP address. A common error that people make is to omit
2653 one component of an IPv4 address, either by accident, or believing that, for
2654 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,
2655 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2656 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2657 ancient specification.) To aid in debugging these cases, we give a specific
2658 error if the pattern contains only digits and dots or contains a slash preceded
2659 only by digits and dots (a slash at the start indicates a file name and of
2660 course slashes may be present in lookups, but not preceded only by digits and
2663 for (t = ss; isdigit(*t) || *t == '.'; t++);
2664 if (*t == 0 || (*t == '/' && t != ss))
2666 *error = US"malformed IPv4 address or address mask";
2670 /* See if there is a semicolon in the pattern */
2672 semicolon = Ustrchr(ss, ';');
2674 /* If we are doing an IP address only match, then all lookups must be IP
2675 address lookups, even if there is no "net-". */
2679 iplookup = semicolon != NULL;
2682 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2683 a lookup on a masked IP network, in textual form. We obey this code even if we
2684 have already set iplookup, so as to skip over the "net-" prefix and to set the
2685 mask length. The net- stuff really only applies to single-key lookups where the
2686 key is implicit. For query-style lookups the key is specified in the query.
2687 From release 4.30, the use of net- for query style is no longer needed, but we
2688 retain it for backward compatibility. */
2690 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2693 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2694 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2695 iplookup = (*t++ == '-');
2699 /* Do the IP address lookup if that is indeed what we have */
2707 uschar *filename, *key, *result;
2710 /* Find the search type */
2712 search_type = search_findtype(t, semicolon - t);
2714 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2715 search_error_message);
2717 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2718 is no file name, and the "key" is just the query. For query-style with a file
2719 name, we have to fish the file off the start of the query. For a single-key
2720 lookup, the key is the current IP address, masked appropriately, and
2721 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2722 dot separators instead of colons, except when the lookup type is "iplsearch".
2725 if (mac_islookup(search_type, lookup_absfilequery))
2727 filename = semicolon + 1;
2729 while (*key != 0 && !isspace(*key)) key++;
2730 filename = string_copyn(filename, key - filename);
2731 while (isspace(*key)) key++;
2733 else if (mac_islookup(search_type, lookup_querystyle))
2736 key = semicolon + 1;
2738 else /* Single-key style */
2740 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2742 insize = host_aton(cb->host_address, incoming);
2743 host_mask(insize, incoming, mlen);
2744 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2746 filename = semicolon + 1;
2749 /* Now do the actual lookup; note that there is no search_close() because
2750 of the caching arrangements. */
2752 handle = search_open(filename, search_type, 0, NULL, NULL);
2753 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2754 search_error_message);
2755 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2756 if (valueptr != NULL) *valueptr = result;
2757 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2760 /* The pattern is not an IP address or network reference of any kind. That is,
2761 it is a host name pattern. If this is an IP only match, there's an error in the
2766 *error = US"cannot match host name in match_ip list";
2770 /* Check the characters of the pattern to see if they comprise only letters,
2771 digits, full stops, and hyphens (the constituents of domain names). Allow
2772 underscores, as they are all too commonly found. Sigh. Also, if
2773 allow_utf8_domains is set, allow top-bit characters. */
2775 for (t = ss; *t != 0; t++)
2776 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2777 (!allow_utf8_domains || *t < 128)) break;
2779 /* If the pattern is a complete domain name, with no fancy characters, look up
2780 its IP address and match against that. Note that a multi-homed host will add
2781 items to the chain. */
2792 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2793 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2796 for (hh = &h; hh != NULL; hh = hh->next)
2798 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2802 if (rc == HOST_FIND_AGAIN) return DEFER;
2803 *error = string_sprintf("failed to find IP address for %s", ss);
2807 /* Almost all subsequent comparisons require the host name, and can be done
2808 using the general string matching function. When this function is called for
2809 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2810 must use sender_host_name and its aliases, looking them up if necessary. */
2812 if (cb->host_name != NULL) /* Explicit host name given */
2813 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2816 /* Host name not given; in principle we need the sender host name and its
2817 aliases. However, for query-style lookups, we do not need the name if the
2818 query does not contain $sender_host_name. From release 4.23, a reference to
2819 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2822 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2825 int partial, affixlen, starflags, id;
2828 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2831 if (id < 0) /* Unknown lookup type */
2833 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2834 search_error_message, ss);
2837 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2842 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2845 case DEFER: return DEFER;
2846 default: return FAIL;
2850 /* Not a query-style lookup; must ensure the host name is present, and then we
2851 do a check on the name and all its aliases. */
2853 if (sender_host_name == NULL)
2855 HDEBUG(D_host_lookup)
2856 debug_printf("sender host name required, to match against %s\n", ss);
2857 if (host_lookup_failed || host_name_lookup() != OK)
2859 *error = string_sprintf("failed to find host name for %s",
2860 sender_host_address);;
2863 host_build_sender_fullhost();
2866 /* Match on the sender host name, using the general matching function */
2868 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2872 case DEFER: return DEFER;
2875 /* If there are aliases, try matching on them. */
2877 aliases = sender_host_aliases;
2878 while (*aliases != NULL)
2880 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2883 case DEFER: return DEFER;
2892 /*************************************************
2893 * Check a specific host matches a host list *
2894 *************************************************/
2896 /* This function is passed a host list containing items in a number of
2897 different formats and the identity of a host. Its job is to determine whether
2898 the given host is in the set of hosts defined by the list. The host name is
2899 passed as a pointer so that it can be looked up if needed and not already
2900 known. This is commonly the case when called from verify_check_host() to check
2901 an incoming connection. When called from elsewhere the host name should usually
2904 This function is now just a front end to match_check_list(), which runs common
2905 code for scanning a list. We pass it the check_host() function to perform a
2909 listptr pointer to the host list
2910 cache_bits pointer to cache for named lists, or NULL
2911 host_name the host name or NULL, implying use sender_host_name and
2912 sender_host_aliases, looking them up if required
2913 host_address the IP address
2914 valueptr if not NULL, data from a lookup is passed back here
2916 Returns: OK if the host is in the defined set
2917 FAIL if the host is not in the defined set,
2918 DEFER if a data lookup deferred (not a host lookup)
2920 If the host name was needed in order to make a comparison, and could not be
2921 determined from the IP address, the result is FAIL unless the item
2922 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2925 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2926 uschar *host_name, uschar *host_address, uschar **valueptr)
2929 unsigned int *local_cache_bits = cache_bits;
2930 uschar *save_host_address = deliver_host_address;
2931 check_host_block cb;
2932 cb.host_name = host_name;
2933 cb.host_address = host_address;
2935 if (valueptr != NULL) *valueptr = NULL;
2937 /* If the host address starts off ::ffff: it is an IPv6 address in
2938 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2941 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2942 host_address + 7 : host_address;
2944 /* During the running of the check, put the IP address into $host_address. In
2945 the case of calls from the smtp transport, it will already be there. However,
2946 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2947 the safe side, any existing setting is preserved, though as I write this
2948 (November 2004) I can't see any cases where it is actually needed. */
2950 deliver_host_address = host_address;
2951 rc = match_check_list(
2952 listptr, /* the list */
2953 0, /* separator character */
2954 &hostlist_anchor, /* anchor pointer */
2955 &local_cache_bits, /* cache pointer */
2956 check_host, /* function for testing */
2957 &cb, /* argument for function */
2958 MCL_HOST, /* type of check */
2959 (host_address == sender_host_address)?
2960 US"host" : host_address, /* text for debugging */
2961 valueptr); /* where to pass back data */
2962 deliver_host_address = save_host_address;
2969 /*************************************************
2970 * Check the remote host matches a list *
2971 *************************************************/
2973 /* This is a front end to verify_check_this_host(), created because checking
2974 the remote host is a common occurrence. With luck, a good compiler will spot
2975 the tail recursion and optimize it. If there's no host address, this is
2976 command-line SMTP input - check against an empty string for the address.
2979 listptr pointer to the host list
2981 Returns: the yield of verify_check_this_host(),
2982 i.e. OK, FAIL, or DEFER
2986 verify_check_host(uschar **listptr)
2988 return verify_check_this_host(listptr, sender_host_cache, NULL,
2989 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2996 /*************************************************
2997 * Invert an IP address *
2998 *************************************************/
3000 /* Originally just used for DNS xBL lists, now also used for the
3001 reverse_ip expansion operator.
3004 buffer where to put the answer
3005 address the address to invert
3009 invert_address(uschar *buffer, uschar *address)
3012 uschar *bptr = buffer;
3014 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3015 to the IPv4 part only. */
3017 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3019 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3022 if (host_aton(address, bin) == 1)
3026 for (i = 0; i < 4; i++)
3028 sprintf(CS bptr, "%d.", x & 255);
3029 while (*bptr) bptr++;
3034 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3035 in any DNS black lists, and the format in which they will be looked up is
3036 unknown. This is just a guess. */
3042 for (j = 3; j >= 0; j--)
3045 for (i = 0; i < 8; i++)
3047 sprintf(CS bptr, "%x.", x & 15);
3048 while (*bptr) bptr++;
3055 /* Remove trailing period -- this is needed so that both arbitrary
3056 dnsbl keydomains and inverted addresses may be combined with the
3057 same format string, "%s.%s" */
3064 /*************************************************
3065 * Perform a single dnsbl lookup *
3066 *************************************************/
3068 /* This function is called from verify_check_dnsbl() below. It is also called
3069 recursively from within itself when domain and domain_txt are different
3070 pointers, in order to get the TXT record from the alternate domain.
3073 domain the outer dnsbl domain
3074 domain_txt alternate domain to lookup TXT record on success; when the
3075 same domain is to be used, domain_txt == domain (that is,
3076 the pointers must be identical, not just the text)
3077 keydomain the current keydomain (for debug message)
3078 prepend subdomain to lookup (like keydomain, but
3079 reversed if IP address)
3080 iplist the list of matching IP addresses, or NULL for "any"
3081 bitmask true if bitmask matching is wanted
3082 match_type condition for 'succeed' result
3083 0 => Any RR in iplist (=)
3084 1 => No RR in iplist (!=)
3085 2 => All RRs in iplist (==)
3086 3 => Some RRs not in iplist (!==)
3087 the two bits are defined as MT_NOT and MT_ALL
3088 defer_return what to return for a defer
3090 Returns: OK if lookup succeeded
3095 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3096 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3102 dnsbl_cache_block *cb;
3103 int old_pool = store_pool;
3104 uschar query[256]; /* DNS domain max length */
3106 /* Construct the specific query domainname */
3108 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3110 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3111 "(ignored): %s...", query);
3115 /* Look for this query in the cache. */
3117 t = tree_search(dnsbl_cache, query);
3119 /* If not cached from a previous lookup, we must do a DNS lookup, and
3120 cache the result in permanent memory. */
3124 store_pool = POOL_PERM;
3126 /* Set up a tree entry to cache the lookup */
3128 t = store_get(sizeof(tree_node) + Ustrlen(query));
3129 Ustrcpy(t->name, query);
3130 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3131 (void)tree_insertnode(&dnsbl_cache, t);
3133 /* Do the DNS loopup . */
3135 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3136 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3137 cb->text_set = FALSE;
3141 /* If the lookup succeeded, cache the RHS address. The code allows for
3142 more than one address - this was for complete generality and the possible
3143 use of A6 records. However, A6 records have been reduced to experimental
3144 status (August 2001) and may die out. So they may never get used at all,
3145 let alone in dnsbl records. However, leave the code here, just in case.
3147 Quite apart from one A6 RR generating multiple addresses, there are DNS
3148 lists that return more than one A record, so we must handle multiple
3149 addresses generated in that way as well. */
3151 if (cb->rc == DNS_SUCCEED)
3154 dns_address **addrp = &(cb->rhs);
3155 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3157 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3159 if (rr->type == T_A)
3161 dns_address *da = dns_address_from_rr(&dnsa, rr);
3165 while (da->next != NULL) da = da->next;
3166 addrp = &(da->next);
3171 /* If we didn't find any A records, change the return code. This can
3172 happen when there is a CNAME record but there are no A records for what
3175 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3178 store_pool = old_pool;
3181 /* Previous lookup was cached */
3185 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3189 /* We now have the result of the DNS lookup, either newly done, or cached
3190 from a previous call. If the lookup succeeded, check against the address
3191 list if there is one. This may be a positive equality list (introduced by
3192 "="), a negative equality list (introduced by "!="), a positive bitmask
3193 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3195 if (cb->rc == DNS_SUCCEED)
3197 dns_address *da = NULL;
3198 uschar *addlist = cb->rhs->address;
3200 /* For A and AAAA records, there may be multiple addresses from multiple
3201 records. For A6 records (currently not expected to be used) there may be
3202 multiple addresses from a single record. */
3204 for (da = cb->rhs->next; da != NULL; da = da->next)
3205 addlist = string_sprintf("%s, %s", addlist, da->address);
3207 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3210 /* Address list check; this can be either for equality, or via a bitmask.
3211 In the latter case, all the bits must match. */
3215 for (da = cb->rhs; da != NULL; da = da->next)
3219 uschar *ptr = iplist;
3222 /* Handle exact matching */
3226 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3228 if (Ustrcmp(CS da->address, ip) == 0) break;
3232 /* Handle bitmask matching */
3239 /* At present, all known DNS blocking lists use A records, with
3240 IPv4 addresses on the RHS encoding the information they return. I
3241 wonder if this will linger on as the last vestige of IPv4 when IPv6
3242 is ubiquitous? Anyway, for now we use paranoia code to completely
3243 ignore IPv6 addresses. The default mask is 0, which always matches.
3244 We change this only for IPv4 addresses in the list. */
3246 if (host_aton(da->address, address) == 1) mask = address[0];
3248 /* Scan the returned addresses, skipping any that are IPv6 */
3250 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3252 if (host_aton(ip, address) != 1) continue;
3253 if ((address[0] & mask) == address[0]) break;
3259 (a) An IP address in an any ('=') list matched, or
3260 (b) No IP address in an all ('==') list matched
3262 then we're done searching. */
3264 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3267 /* If da == NULL, either
3269 (a) No IP address in an any ('=') list matched, or
3270 (b) An IP address in an all ('==') list didn't match
3272 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3275 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3283 res = US"was no match";
3286 res = US"was an exclude match";
3289 res = US"was an IP address that did not match";
3292 res = US"were no IP addresses that did not match";
3295 debug_printf("=> but we are not accepting this block class because\n");
3296 debug_printf("=> there %s for %s%c%s\n",
3298 ((match_type & MT_ALL) == 0)? "" : "=",
3299 bitmask? '&' : '=', iplist);
3305 /* Either there was no IP list, or the record matched, implying that the
3306 domain is on the list. We now want to find a corresponding TXT record. If an
3307 alternate domain is specified for the TXT record, call this function
3308 recursively to look that up; this has the side effect of re-checking that
3309 there is indeed an A record at the alternate domain. */
3311 if (domain_txt != domain)
3312 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3313 FALSE, match_type, defer_return);
3315 /* If there is no alternate domain, look up a TXT record in the main domain
3316 if it has not previously been cached. */
3320 cb->text_set = TRUE;
3321 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3324 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3326 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3327 if (rr->type == T_TXT) break;
3330 int len = (rr->data)[0];
3331 if (len > 511) len = 127;
3332 store_pool = POOL_PERM;
3333 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3334 store_pool = old_pool;
3339 dnslist_value = addlist;
3340 dnslist_text = cb->text;
3344 /* There was a problem with the DNS lookup */
3346 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3348 log_write(L_dnslist_defer, LOG_MAIN,
3349 "DNS list lookup defer (probably timeout) for %s: %s", query,
3350 (defer_return == OK)? US"assumed in list" :
3351 (defer_return == FAIL)? US"assumed not in list" :
3352 US"returned DEFER");
3353 return defer_return;
3356 /* No entry was found in the DNS; continue for next domain */
3360 debug_printf("DNS lookup for %s failed\n", query);
3361 debug_printf("=> that means %s is not listed at %s\n",
3371 /*************************************************
3372 * Check host against DNS black lists *
3373 *************************************************/
3375 /* This function runs checks against a list of DNS black lists, until one
3376 matches. Each item on the list can be of the form
3378 domain=ip-address/key
3380 The domain is the right-most domain that is used for the query, for example,
3381 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3382 if the DNS lookup returns a matching IP address. Several addresses may be
3383 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3385 If no key is given, what is looked up in the domain is the inverted IP address
3386 of the current client host. If a key is given, it is used to construct the
3387 domain for the lookup. For example:
3389 dsn.rfc-ignorant.org/$sender_address_domain
3391 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3392 then we check for a TXT record for an error message, and if found, save its
3393 value in $dnslist_text. We also cache everything in a tree, to optimize
3396 The TXT record is normally looked up in the same domain as the A record, but
3397 when many lists are combined in a single DNS domain, this will not be a very
3398 specific message. It is possible to specify a different domain for looking up
3399 TXT records; this is given before the main domain, comma-separated. For
3402 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3403 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3405 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3407 Note: an address for testing RBL is 192.203.178.39
3408 Note: an address for testing DUL is 192.203.178.4
3409 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3412 listptr the domain/address/data list
3414 Returns: OK successful lookup (i.e. the address is on the list), or
3415 lookup deferred after +include_unknown
3416 FAIL name not found, or no data found for the given type, or
3417 lookup deferred after +exclude_unknown (default)
3418 DEFER lookup failure, if +defer_unknown was set
3422 verify_check_dnsbl(uschar **listptr)
3425 int defer_return = FAIL;
3426 uschar *list = *listptr;
3429 uschar buffer[1024];
3430 uschar revadd[128]; /* Long enough for IPv6 address */
3432 /* Indicate that the inverted IP address is not yet set up */
3436 /* In case this is the first time the DNS resolver is being used. */
3438 dns_init(FALSE, FALSE);
3440 /* Loop through all the domains supplied, until something matches */
3442 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3445 BOOL bitmask = FALSE;
3452 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3454 /* Deal with special values that change the behaviour on defer */
3456 if (domain[0] == '+')
3458 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3459 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3460 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3462 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3467 /* See if there's explicit data to be looked up */
3469 key = Ustrchr(domain, '/');
3470 if (key != NULL) *key++ = 0;
3472 /* See if there's a list of addresses supplied after the domain name. This is
3473 introduced by an = or a & character; if preceded by = we require all matches
3474 and if preceded by ! we invert the result. */
3476 iplist = Ustrchr(domain, '=');
3480 iplist = Ustrchr(domain, '&');
3483 if (iplist != NULL) /* Found either = or & */
3485 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3487 match_type |= MT_NOT;
3491 *iplist++ = 0; /* Terminate domain, move on */
3493 /* If we found = (bitmask == FALSE), check for == or =& */
3495 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3497 bitmask = *iplist++ == '&';
3498 match_type |= MT_ALL;
3502 /* If there is a comma in the domain, it indicates that a second domain for
3503 looking up TXT records is provided, before the main domain. Otherwise we must
3504 set domain_txt == domain. */
3506 domain_txt = domain;
3507 comma = Ustrchr(domain, ',');
3514 /* Check that what we have left is a sensible domain name. There is no reason
3515 why these domains should in fact use the same syntax as hosts and email
3516 domains, but in practice they seem to. However, there is little point in
3517 actually causing an error here, because that would no doubt hold up incoming
3518 mail. Instead, I'll just log it. */
3520 for (s = domain; *s != 0; s++)
3522 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3524 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3525 "strange characters - is this right?", domain);
3530 /* Check the alternate domain if present */
3532 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3534 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3536 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3537 "strange characters - is this right?", domain_txt);
3542 /* If there is no key string, construct the query by adding the domain name
3543 onto the inverted host address, and perform a single DNS lookup. */
3547 if (sender_host_address == NULL) return FAIL; /* can never match */
3548 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3549 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3550 iplist, bitmask, match_type, defer_return);
3553 dnslist_domain = string_copy(domain_txt);
3554 dnslist_matched = string_copy(sender_host_address);
3555 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3556 sender_host_address, dnslist_domain);
3558 if (rc != FAIL) return rc; /* OK or DEFER */
3561 /* If there is a key string, it can be a list of domains or IP addresses to
3562 be concatenated with the main domain. */
3569 uschar keybuffer[256];
3570 uschar keyrevadd[128];
3572 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3573 sizeof(keybuffer))) != NULL)
3575 uschar *prepend = keydomain;
3577 if (string_is_ip_address(keydomain, NULL) != 0)
3579 invert_address(keyrevadd, keydomain);
3580 prepend = keyrevadd;
3583 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3584 bitmask, match_type, defer_return);
3588 dnslist_domain = string_copy(domain_txt);
3589 dnslist_matched = string_copy(keydomain);
3590 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3591 keydomain, dnslist_domain);
3595 /* If the lookup deferred, remember this fact. We keep trying the rest
3596 of the list to see if we get a useful result, and if we don't, we return
3597 DEFER at the end. */
3599 if (rc == DEFER) defer = TRUE;
3600 } /* continue with next keystring domain/address */
3602 if (defer) return DEFER;
3604 } /* continue with next dnsdb outer domain */
3609 /* End of verify.c */