1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 address_item cutthrough_addr;
18 static smtp_outblock ctblock;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if ((options & vopt_callout_recipsender) != 0)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if ((options & vopt_callout_recippmaster) != 0)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
378 smtp_transport_options_block *ob =
379 (smtp_transport_options_block *)(addr->transport->options_block);
381 /* The information wasn't available in the cache, so we have to do a real
382 callout and save the result in the cache for next time, unless no_cache is set,
383 or unless we have a previously cached negative random result. If we are to test
384 with a random local part, ensure that such a local part is available. If not,
385 log the fact, but carry on without randomming. */
387 if (callout_random && callout_random_local_part != NULL)
389 random_local_part = expand_string(callout_random_local_part);
390 if (random_local_part == NULL)
391 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
392 "callout_random_local_part: %s", expand_string_message);
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
408 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
410 /* Now make connections to the hosts and do real callouts. The list of hosts
411 is passed in as an argument. */
413 for (host = host_list; host != NULL && !done; host = host->next)
415 smtp_inblock inblock;
416 smtp_outblock outblock;
419 BOOL send_quit = TRUE;
420 uschar *active_hostname = smtp_active_hostname;
424 BOOL suppress_tls = FALSE;
425 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
426 uschar inbuffer[4096];
427 uschar outbuffer[1024];
428 uschar responsebuffer[4096];
430 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
431 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
433 /* Skip this host if we don't have an IP address for it. */
435 if (host->address == NULL)
437 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
442 /* Check the overall callout timeout */
444 if (time(NULL) - callout_start_time >= callout_overall)
446 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
450 /* Set IPv4 or IPv6 */
452 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
454 /* Expand and interpret the interface and port strings. The latter will not
455 be used if there is a host-specific port (e.g. from a manualroute router).
456 This has to be delayed till now, because they may expand differently for
457 different hosts. If there's a failure, log it, but carry on with the
460 deliver_host = host->name;
461 deliver_host_address = host->address;
462 deliver_domain = addr->domain;
464 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
466 !smtp_get_port(tf->port, addr, &port, US"callout"))
467 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
470 /* Set HELO string according to the protocol */
471 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
472 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
475 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
477 /* Set up the buffer for reading SMTP response packets. */
479 inblock.buffer = inbuffer;
480 inblock.buffersize = sizeof(inbuffer);
481 inblock.ptr = inbuffer;
482 inblock.ptrend = inbuffer;
484 /* Set up the buffer for holding SMTP commands while pipelining */
486 outblock.buffer = outbuffer;
487 outblock.buffersize = sizeof(outbuffer);
488 outblock.ptr = outbuffer;
489 outblock.cmd_count = 0;
490 outblock.authenticating = FALSE;
492 /* Reset the parameters of a TLS session */
493 tls_out.cipher = tls_out.peerdn = NULL;
495 /* Connect to the host; on failure, just loop for the next one, but we
496 set the error for the last one. Use the callout_connect timeout. */
498 tls_retry_connection:
500 inblock.sock = outblock.sock =
501 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
502 /* reconsider DSCP here */
503 if (inblock.sock < 0)
505 addr->message = string_sprintf("could not connect to %s [%s]: %s",
506 host->name, host->address, strerror(errno));
507 deliver_host = deliver_host_address = NULL;
508 deliver_domain = save_deliver_domain;
512 /* Expand the helo_data string to find the host name to use. */
514 if (tf->helo_data != NULL)
516 uschar *s = expand_string(tf->helo_data);
518 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
519 "helo_data value for callout: %s", addr->address,
520 expand_string_message);
521 else active_hostname = s;
524 deliver_host = deliver_host_address = NULL;
525 deliver_domain = save_deliver_domain;
527 /* Wait for initial response, and send HELO. The smtp_write_command()
528 function leaves its command in big_buffer. This is used in error responses.
529 Initialize it in case the connection is rejected. */
531 Ustrcpy(big_buffer, "initial connection");
533 /* Unless ssl-on-connect, wait for the initial greeting */
537 if (!smtps || (smtps && tls_out.active >= 0))
539 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
540 goto RESPONSE_FAILED;
542 /* Not worth checking greeting line for ESMTP support */
543 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
544 host->name, host->address, NULL) != OK))
546 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
551 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
554 ob->tls_tempfail_tryclear = FALSE;
556 else /* all other cases */
561 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
562 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
564 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
566 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
569 goto RESPONSE_FAILED;
575 goto esmtp_retry; /* fallback to HELO */
578 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
580 if (esmtp && !suppress_tls && tls_out.active < 0)
582 if (regex_STARTTLS == NULL) regex_STARTTLS =
583 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
585 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
586 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
593 /* If TLS is available on this connection attempt to
594 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
595 send another EHLO - the server may give a different answer in secure mode. We
596 use a separate buffer for reading the response to STARTTLS so that if it is
597 negative, the original EHLO data is available for subsequent analysis, should
598 the client not be required to use TLS. If the response is bad, copy the buffer
599 for error analysis. */
603 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
604 host->address, NULL) != OK &&
605 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
606 host->address, NULL) != OK
609 uschar buffer2[4096];
611 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
614 /* If there is an I/O error, transmission of this message is deferred. If
615 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
616 false, we also defer. However, if there is a temporary rejection of STARTTLS
617 and tls_tempfail_tryclear is true, or if there is an outright rejection of
618 STARTTLS, we carry on. This means we will try to send the message in clear,
619 unless the host is in hosts_require_tls (tested below). */
621 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
622 ob->command_timeout))
624 if (errno != 0 || buffer2[0] == 0 ||
625 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
627 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
629 goto RESPONSE_FAILED;
633 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
636 int rc = tls_client_start(inblock.sock, host, addr,
637 NULL, /* No DH param */
638 ob->tls_certificate, ob->tls_privatekey,
640 ob->tls_verify_certificates, ob->tls_crl,
641 ob->tls_require_ciphers, ob->tls_dh_min_bits,
644 /* TLS negotiation failed; give an error. Try in clear on a new connection,
645 if the options permit it for this host. */
648 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
649 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
650 host->address, NULL) != OK)
652 (void)close(inblock.sock);
653 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
654 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
656 goto tls_retry_connection;
658 /*save_errno = ERRNO_TLSFAILURE;*/
659 /*message = US"failure while setting up TLS session";*/
665 /* TLS session is set up. Copy info for logging. */
666 addr->cipher = tls_out.cipher;
667 addr->peerdn = tls_out.peerdn;
669 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
671 goto smtps_redo_greeting;
673 /* For STARTTLS we need to redo EHLO */
678 /* If the host is required to use a secure channel, ensure that we have one. */
679 if (tls_out.active < 0)
680 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
681 host->address, NULL) == OK)
683 /*save_errno = ERRNO_TLSREQUIRED;*/
684 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
685 host->name, host->address,
686 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
691 #endif /*SUPPORT_TLS*/
693 done = TRUE; /* so far so good; have response to HELO */
695 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING, AUTH */
696 /* If we haven't authenticated, but are required to, give up. */
698 /*XXX "filter command specified for this transport" ??? */
699 /* for now, transport_filter by cutthrough-delivery is not supported */
700 /* Need proper integration with the proper transport mechanism. */
707 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
710 /* Failure to accept HELO is cached; this blocks the whole domain for all
711 senders. I/O errors and defer responses are not cached. */
715 *failure_ptr = US"mail"; /* At or before MAIL */
716 if (errno == 0 && responsebuffer[0] == '5')
718 setflag(addr, af_verify_nsfail);
719 new_domain_record.result = ccache_reject;
723 /* Send the MAIL command */
726 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
727 from_address) >= 0 &&
728 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
731 /* If the host does not accept MAIL FROM:<>, arrange to cache this
732 information, but again, don't record anything for an I/O error or a defer. Do
733 not cache rejections of MAIL when a non-empty sender has been used, because
734 that blocks the whole domain for all senders. */
738 *failure_ptr = US"mail"; /* At or before MAIL */
739 if (errno == 0 && responsebuffer[0] == '5')
741 setflag(addr, af_verify_nsfail);
742 if (from_address[0] == 0)
743 new_domain_record.result = ccache_reject_mfnull;
747 /* Otherwise, proceed to check a "random" address (if required), then the
748 given address, and the postmaster address (if required). Between each check,
749 issue RSET, because some servers accept only one recipient after MAIL
752 Before doing this, set the result in the domain cache record to "accept",
753 unless its previous value was ccache_reject_mfnull. In that case, the domain
754 rejects MAIL FROM:<> and we want to continue to remember that. When that is
755 the case, we have got here only in the case of a recipient verification with
756 a non-null sender. */
760 new_domain_record.result =
761 (old_domain_cache_result == ccache_reject_mfnull)?
762 ccache_reject_mfnull: ccache_accept;
764 /* Do the random local part check first */
766 if (random_local_part != NULL)
768 uschar randombuffer[1024];
770 smtp_write_command(&outblock, FALSE,
771 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
772 addr->domain) >= 0 &&
773 smtp_read_response(&inblock, randombuffer,
774 sizeof(randombuffer), '2', callout);
776 /* Remember when we last did a random test */
778 new_domain_record.random_stamp = time(NULL);
780 /* If accepted, we aren't going to do any further tests below. */
784 new_domain_record.random_result = ccache_accept;
787 /* Otherwise, cache a real negative response, and get back to the right
788 state to send RCPT. Unless there's some problem such as a dropped
789 connection, we expect to succeed, because the commands succeeded above. */
793 if (randombuffer[0] == '5')
794 new_domain_record.random_result = ccache_reject;
797 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
798 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
801 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
802 from_address) >= 0 &&
803 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
806 else done = FALSE; /* Some timeout/connection problem */
809 /* If the host is accepting all local parts, as determined by the "random"
810 check, we don't need to waste time doing any further checking. */
812 if (new_domain_record.random_result != ccache_accept && done)
814 /* Get the rcpt_include_affixes flag from the transport if there is one,
815 but assume FALSE if there is not. */
818 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
819 transport_rcpt_address(addr,
820 (addr->transport == NULL)? FALSE :
821 addr->transport->rcpt_include_affixes)) >= 0 &&
822 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
826 new_address_record.result = ccache_accept;
827 else if (errno == 0 && responsebuffer[0] == '5')
829 *failure_ptr = US"recipient";
830 new_address_record.result = ccache_reject;
833 /* Do postmaster check if requested; if a full check is required, we
834 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
836 if (done && pm_mailfrom != NULL)
838 /*XXX not suitable for cutthrough - sequencing problems */
839 cutthrough_delivery= FALSE;
840 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
843 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
844 smtp_read_response(&inblock, responsebuffer,
845 sizeof(responsebuffer), '2', callout) &&
847 smtp_write_command(&outblock, FALSE,
848 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
849 smtp_read_response(&inblock, responsebuffer,
850 sizeof(responsebuffer), '2', callout) &&
852 /* First try using the current domain */
855 smtp_write_command(&outblock, FALSE,
856 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
857 smtp_read_response(&inblock, responsebuffer,
858 sizeof(responsebuffer), '2', callout)
863 /* If that doesn't work, and a full check is requested,
864 try without the domain. */
867 (options & vopt_callout_fullpm) != 0 &&
868 smtp_write_command(&outblock, FALSE,
869 "RCPT TO:<postmaster>\r\n") >= 0 &&
870 smtp_read_response(&inblock, responsebuffer,
871 sizeof(responsebuffer), '2', callout)
874 /* Sort out the cache record */
876 new_domain_record.postmaster_stamp = time(NULL);
879 new_domain_record.postmaster_result = ccache_accept;
880 else if (errno == 0 && responsebuffer[0] == '5')
882 *failure_ptr = US"postmaster";
883 setflag(addr, af_verify_pmfail);
884 new_domain_record.postmaster_result = ccache_reject;
887 } /* Random not accepted */
888 } /* MAIL FROM: accepted */
890 /* For any failure of the main check, other than a negative response, we just
891 close the connection and carry on. We can identify a negative response by the
892 fact that errno is zero. For I/O errors it will be non-zero
894 Set up different error texts for logging and for sending back to the caller
895 as an SMTP response. Log in all cases, using a one-line format. For sender
896 callouts, give a full response to the caller, but for recipient callouts,
897 don't give the IP address because this may be an internal host whose identity
898 is not to be widely broadcast. */
902 if (errno == ETIMEDOUT)
904 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
909 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
912 string_sprintf("response to \"%s\" from %s [%s] was: %s",
913 big_buffer, host->name, host->address,
914 string_printing(responsebuffer));
916 addr->user_message = is_recipient?
917 string_sprintf("Callout verification failed:\n%s", responsebuffer)
919 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
920 host->address, big_buffer, responsebuffer);
922 /* Hard rejection ends the process */
924 if (responsebuffer[0] == '5') /* Address rejected */
932 /* End the SMTP conversation and close the connection. */
934 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
935 and we have no cutthrough conn so far
936 here is where we want to leave the conn open */
937 if ( cutthrough_delivery
940 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
941 && !random_local_part
946 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
947 cutthrough_addr = *addr; /* Save the address_item for later logging */
948 cutthrough_addr.host_used = store_get(sizeof(host_item));
949 cutthrough_addr.host_used->name = host->name;
950 cutthrough_addr.host_used->address = host->address;
951 cutthrough_addr.host_used->port = port;
953 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
954 ctblock.buffer = ctbuffer;
955 ctblock.buffersize = sizeof(ctbuffer);
956 ctblock.ptr = ctbuffer;
957 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
958 ctblock.sock = cutthrough_fd;
962 /* Ensure no cutthrough on multiple address verifies */
963 if (options & vopt_callout_recipsender)
964 cancel_cutthrough_connection("multiple verify calls");
965 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
968 tls_close(FALSE, TRUE);
970 (void)close(inblock.sock);
973 } /* Loop through all hosts, while !done */
976 /* If we get here with done == TRUE, a successful callout happened, and yield
977 will be set OK or FAIL according to the response to the RCPT command.
978 Otherwise, we looped through the hosts but couldn't complete the business.
979 However, there may be domain-specific information to cache in both cases.
981 The value of the result field in the new_domain record is ccache_unknown if
982 there was an error before or with MAIL FROM:, and errno was not zero,
983 implying some kind of I/O error. We don't want to write the cache in that case.
984 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
986 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
988 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
991 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
995 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
996 (int)sizeof(dbdata_callout_cache));
997 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
998 " result=%d postmaster=%d random=%d\n",
999 new_domain_record.result,
1000 new_domain_record.postmaster_result,
1001 new_domain_record.random_result);
1005 /* If a definite result was obtained for the callout, cache it unless caching
1010 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1012 if (dbm_file == NULL)
1013 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1014 if (dbm_file == NULL)
1016 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1020 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1021 (int)sizeof(dbdata_callout_cache_address));
1022 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1023 (new_address_record.result == ccache_accept)? "positive" : "negative");
1028 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1029 temporary error. If there was only one host, and a response was received, leave
1030 it alone if supplying details. Otherwise, give a generic response. */
1034 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1035 is_recipient? "recipient" : "sender");
1038 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1040 addr->user_message = (!smtp_return_error_details)? dullmsg :
1041 string_sprintf("%s for <%s>.\n"
1042 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1043 "they may be permanently unreachable from this server. In the latter case,\n%s",
1044 dullmsg, addr->address,
1046 "the address will never be accepted."
1048 "you need to change the address or create an MX record for its domain\n"
1049 "if it is supposed to be generally accessible from the Internet.\n"
1050 "Talk to your mail administrator for details.");
1052 /* Force a specific error code */
1054 addr->basic_errno = ERRNO_CALLOUTDEFER;
1057 /* Come here from within the cache-reading code on fast-track exit. */
1060 if (dbm_file != NULL) dbfn_close(dbm_file);
1066 /* Called after recipient-acl to get a cutthrough connection open when
1067 one was requested and a recipient-verify wasn't subsequently done.
1070 open_cutthrough_connection( address_item * addr )
1074 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1075 /* We must use a copy of the address for verification, because it might
1079 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1080 (void) verify_address(&addr2, NULL,
1081 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1082 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1084 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1090 /* Send given number of bytes from the buffer */
1092 cutthrough_send(int n)
1094 if(cutthrough_fd < 0)
1099 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1101 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1104 transport_count += n;
1105 ctblock.ptr= ctblock.buffer;
1109 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1116 _cutthrough_puts(uschar * cp, int n)
1120 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1121 if(!cutthrough_send(ctblock.buffersize))
1124 *ctblock.ptr++ = *cp++;
1129 /* Buffered output of counted data block. Return boolean success */
1131 cutthrough_puts(uschar * cp, int n)
1133 if (cutthrough_fd < 0) return TRUE;
1134 if (_cutthrough_puts(cp, n)) return TRUE;
1135 cancel_cutthrough_connection("transmit failed");
1141 _cutthrough_flush_send( void )
1143 int n= ctblock.ptr-ctblock.buffer;
1146 if(!cutthrough_send(n))
1152 /* Send out any bufferred output. Return boolean success. */
1154 cutthrough_flush_send( void )
1156 if (_cutthrough_flush_send()) return TRUE;
1157 cancel_cutthrough_connection("transmit failed");
1163 cutthrough_put_nl( void )
1165 return cutthrough_puts(US"\r\n", 2);
1169 /* Get and check response from cutthrough target */
1171 cutthrough_response(char expect, uschar ** copy)
1173 smtp_inblock inblock;
1174 uschar inbuffer[4096];
1175 uschar responsebuffer[4096];
1177 inblock.buffer = inbuffer;
1178 inblock.buffersize = sizeof(inbuffer);
1179 inblock.ptr = inbuffer;
1180 inblock.ptrend = inbuffer;
1181 inblock.sock = cutthrough_fd;
1182 /* this relies on (inblock.sock == tls_out.active) */
1183 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1184 cancel_cutthrough_connection("target timeout on read");
1189 *copy= cp= string_copy(responsebuffer);
1190 /* Trim the trailing end of line */
1191 cp += Ustrlen(responsebuffer);
1192 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1193 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1196 return responsebuffer[0];
1200 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1202 cutthrough_predata( void )
1204 if(cutthrough_fd < 0)
1207 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1208 cutthrough_puts(US"DATA\r\n", 6);
1209 cutthrough_flush_send();
1211 /* Assume nothing buffered. If it was it gets ignored. */
1212 return cutthrough_response('3', NULL) == '3';
1216 /* Buffered send of headers. Return success boolean. */
1217 /* Expands newlines to wire format (CR,NL). */
1218 /* Also sends header-terminating blank line. */
1220 cutthrough_headers_send( void )
1223 uschar * cp1, * cp2;
1225 if(cutthrough_fd < 0)
1228 for(h= header_list; h != NULL; h= h->next)
1229 if(h->type != htype_old && h->text != NULL)
1230 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1231 if( !cutthrough_puts(cp1, cp2-cp1)
1232 || !cutthrough_put_nl())
1235 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1236 return cutthrough_put_nl();
1241 close_cutthrough_connection( const char * why )
1243 if(cutthrough_fd >= 0)
1245 /* We could be sending this after a bunch of data, but that is ok as
1246 the only way to cancel the transfer in dataphase is to drop the tcp
1247 conn before the final dot.
1249 ctblock.ptr = ctbuffer;
1250 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1251 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1252 _cutthrough_flush_send();
1253 /* No wait for response */
1256 tls_close(FALSE, TRUE);
1258 (void)close(cutthrough_fd);
1260 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1262 ctblock.ptr = ctbuffer;
1266 cancel_cutthrough_connection( const char * why )
1268 close_cutthrough_connection(why);
1269 cutthrough_delivery= FALSE;
1275 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1276 Log an OK response as a transmission.
1277 Close the connection.
1278 Return smtp response-class digit.
1281 cutthrough_finaldot( void )
1283 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1285 /* Assume data finshed with new-line */
1286 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1287 return cutthrough_addr.message;
1289 switch(cutthrough_response('2', &cutthrough_addr.message))
1292 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1293 close_cutthrough_connection("delivered");
1297 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1301 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1307 return cutthrough_addr.message;
1312 /*************************************************
1313 * Copy error to toplevel address *
1314 *************************************************/
1316 /* This function is used when a verify fails or defers, to ensure that the
1317 failure or defer information is in the original toplevel address. This applies
1318 when an address is redirected to a single new address, and the failure or
1319 deferral happens to the child address.
1322 vaddr the verify address item
1323 addr the final address item
1326 Returns: the value of YIELD
1330 copy_error(address_item *vaddr, address_item *addr, int yield)
1334 vaddr->message = addr->message;
1335 vaddr->user_message = addr->user_message;
1336 vaddr->basic_errno = addr->basic_errno;
1337 vaddr->more_errno = addr->more_errno;
1338 vaddr->p.address_data = addr->p.address_data;
1339 copyflag(vaddr, addr, af_pass_message);
1347 /**************************************************
1348 * printf that automatically handles TLS if needed *
1349 ***************************************************/
1351 /* This function is used by verify_address() as a substitute for all fprintf()
1352 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1353 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1354 that assumes that we always use the smtp_out FILE* when not using TLS or the
1355 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1356 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1360 f the candidate FILE* to write to
1361 format format string
1362 ... optional arguments
1368 static void PRINTF_FUNCTION(2,3)
1369 respond_printf(FILE *f, const char *format, ...)
1373 va_start(ap, format);
1374 if (smtp_out && (f == smtp_out))
1375 smtp_vprintf(format, ap);
1377 vfprintf(f, format, ap);
1383 /*************************************************
1384 * Verify an email address *
1385 *************************************************/
1387 /* This function is used both for verification (-bv and at other times) and
1388 address testing (-bt), which is indicated by address_test_mode being set.
1391 vaddr contains the address to verify; the next field in this block
1393 f if not NULL, write the result to this file
1394 options various option bits:
1395 vopt_fake_sender => this sender verify is not for the real
1396 sender (it was verify=sender=xxxx or an address from a
1397 header line) - rewriting must not change sender_address
1398 vopt_is_recipient => this is a recipient address, otherwise
1399 it's a sender address - this affects qualification and
1400 rewriting and messages from callouts
1401 vopt_qualify => qualify an unqualified address; else error
1402 vopt_expn => called from SMTP EXPN command
1403 vopt_success_on_redirect => when a new address is generated
1404 the verification instantly succeeds
1406 These ones are used by do_callout() -- the options variable
1409 vopt_callout_fullpm => if postmaster check, do full one
1410 vopt_callout_no_cache => don't use callout cache
1411 vopt_callout_random => do the "random" thing
1412 vopt_callout_recipsender => use real sender for recipient
1413 vopt_callout_recippmaster => use postmaster for recipient
1415 callout if > 0, specifies that callout is required, and gives timeout
1416 for individual commands
1417 callout_overall if > 0, gives overall timeout for the callout function;
1418 if < 0, a default is used (see do_callout())
1419 callout_connect the connection timeout for callouts
1420 se_mailfrom when callout is requested to verify a sender, use this
1421 in MAIL FROM; NULL => ""
1422 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1423 thing and use this as the sender address (may be "")
1425 routed if not NULL, set TRUE if routing succeeded, so we can
1426 distinguish between routing failed and callout failed
1428 Returns: OK address verified
1429 FAIL address failed to verify
1430 DEFER can't tell at present
1434 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1435 int callout_overall, int callout_connect, uschar *se_mailfrom,
1436 uschar *pm_mailfrom, BOOL *routed)
1439 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1440 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1441 BOOL expn = (options & vopt_expn) != 0;
1442 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1445 int verify_type = expn? v_expn :
1446 address_test_mode? v_none :
1447 is_recipient? v_recipient : v_sender;
1448 address_item *addr_list;
1449 address_item *addr_new = NULL;
1450 address_item *addr_remote = NULL;
1451 address_item *addr_local = NULL;
1452 address_item *addr_succeed = NULL;
1453 uschar **failure_ptr = is_recipient?
1454 &recipient_verify_failure : &sender_verify_failure;
1455 uschar *ko_prefix, *cr;
1456 uschar *address = vaddr->address;
1457 uschar *save_sender;
1458 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1460 /* Clear, just in case */
1462 *failure_ptr = NULL;
1464 /* Set up a prefix and suffix for error message which allow us to use the same
1465 output statements both in EXPN mode (where an SMTP response is needed) and when
1466 debugging with an output file. */
1470 ko_prefix = US"553 ";
1473 else ko_prefix = cr = US"";
1475 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1477 if (parse_find_at(address) == NULL)
1479 if ((options & vopt_qualify) == 0)
1482 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1483 ko_prefix, address, cr);
1484 *failure_ptr = US"qualify";
1487 address = rewrite_address_qualify(address, is_recipient);
1492 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1493 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1496 /* Rewrite and report on it. Clear the domain and local part caches - these
1497 may have been set by domains and local part tests during an ACL. */
1499 if (global_rewrite_rules != NULL)
1501 uschar *old = address;
1502 address = rewrite_address(address, is_recipient, FALSE,
1503 global_rewrite_rules, rewrite_existflags);
1506 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1507 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1508 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1512 /* If this is the real sender address, we must update sender_address at
1513 this point, because it may be referred to in the routers. */
1515 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1516 sender_address = address;
1518 /* If the address was rewritten to <> no verification can be done, and we have
1519 to return OK. This rewriting is permitted only for sender addresses; for other
1520 addresses, such rewriting fails. */
1522 if (address[0] == 0) return OK;
1524 /* Save a copy of the sender address for re-instating if we change it to <>
1525 while verifying a sender address (a nice bit of self-reference there). */
1527 save_sender = sender_address;
1529 /* Update the address structure with the possibly qualified and rewritten
1530 address. Set it up as the starting address on the chain of new addresses. */
1532 vaddr->address = address;
1535 /* We need a loop, because an address can generate new addresses. We must also
1536 cope with generated pipes and files at the top level. (See also the code and
1537 comment in deliver.c.) However, it is usually the case that the router for
1538 user's .forward files has its verify flag turned off.
1540 If an address generates more than one child, the loop is used only when
1541 full_info is set, and this can only be set locally. Remote enquiries just get
1542 information about the top level address, not anything that it generated. */
1544 while (addr_new != NULL)
1547 address_item *addr = addr_new;
1549 addr_new = addr->next;
1554 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1555 debug_printf("Considering %s\n", addr->address);
1558 /* Handle generated pipe, file or reply addresses. We don't get these
1559 when handling EXPN, as it does only one level of expansion. */
1561 if (testflag(addr, af_pfr))
1568 if (addr->address[0] == '>')
1570 allow = testflag(addr, af_allow_reply);
1571 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1575 allow = (addr->address[0] == '|')?
1576 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1577 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1580 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1581 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1582 "%s\n", addr->message);
1584 fprintf(f, "\n transport = %s\n", addr->transport->name);
1586 fprintf(f, " *** forbidden ***\n");
1591 /* Just in case some router parameter refers to it. */
1593 return_path = (addr->p.errors_address != NULL)?
1594 addr->p.errors_address : sender_address;
1596 /* Split the address into domain and local part, handling the %-hack if
1597 necessary, and then route it. While routing a sender address, set
1598 $sender_address to <> because that is what it will be if we were trying to
1599 send a bounce to the sender. */
1601 if (routed != NULL) *routed = FALSE;
1602 if ((rc = deliver_split_address(addr)) == OK)
1604 if (!is_recipient) sender_address = null_sender;
1605 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1606 &addr_succeed, verify_type);
1607 sender_address = save_sender; /* Put back the real sender */
1610 /* If routing an address succeeded, set the flag that remembers, for use when
1611 an ACL cached a sender verify (in case a callout fails). Then if routing set
1612 up a list of hosts or the transport has a host list, and the callout option
1613 is set, and we aren't in a host checking run, do the callout verification,
1614 and set another flag that notes that a callout happened. */
1618 if (routed != NULL) *routed = TRUE;
1621 host_item *host_list = addr->host_list;
1623 /* Make up some data for use in the case where there is no remote
1626 transport_feedback tf = {
1627 NULL, /* interface (=> any) */
1628 US"smtp", /* port */
1629 US"smtp", /* protocol */
1631 US"$smtp_active_hostname", /* helo_data */
1632 FALSE, /* hosts_override */
1633 FALSE, /* hosts_randomize */
1634 FALSE, /* gethostbyname */
1635 TRUE, /* qualify_single */
1636 FALSE /* search_parents */
1639 /* If verification yielded a remote transport, we want to use that
1640 transport's options, so as to mimic what would happen if we were really
1641 sending a message to this address. */
1643 if (addr->transport != NULL && !addr->transport->info->local)
1645 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1647 /* If the transport has hosts and the router does not, or if the
1648 transport is configured to override the router's hosts, we must build a
1649 host list of the transport's hosts, and find the IP addresses */
1651 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1654 uschar *save_deliver_domain = deliver_domain;
1655 uschar *save_deliver_localpart = deliver_localpart;
1657 host_list = NULL; /* Ignore the router's hosts */
1659 deliver_domain = addr->domain;
1660 deliver_localpart = addr->local_part;
1661 s = expand_string(tf.hosts);
1662 deliver_domain = save_deliver_domain;
1663 deliver_localpart = save_deliver_localpart;
1667 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1668 "\"%s\" in %s transport for callout: %s", tf.hosts,
1669 addr->transport->name, expand_string_message);
1674 uschar *canonical_name;
1675 host_item *host, *nexthost;
1676 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1678 /* Just ignore failures to find a host address. If we don't manage
1679 to find any addresses, the callout will defer. Note that more than
1680 one address may be found for a single host, which will result in
1681 additional host items being inserted into the chain. Hence we must
1682 save the next host first. */
1684 flags = HOST_FIND_BY_A;
1685 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1686 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1688 for (host = host_list; host != NULL; host = nexthost)
1690 nexthost = host->next;
1691 if (tf.gethostbyname ||
1692 string_is_ip_address(host->name, NULL) != 0)
1693 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1695 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1696 &canonical_name, NULL);
1702 /* Can only do a callout if we have at least one host! If the callout
1703 fails, it will have set ${sender,recipient}_verify_failure. */
1705 if (host_list != NULL)
1707 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1708 if (host_checking && !host_checking_callout)
1711 debug_printf("... callout omitted by default when host testing\n"
1712 "(Use -bhc if you want the callouts to happen.)\n");
1717 deliver_set_expansions(addr);
1719 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1720 callout_connect, options, se_mailfrom, pm_mailfrom);
1725 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1726 "transport provided a host list\n");
1731 /* Otherwise, any failure is a routing failure */
1733 else *failure_ptr = US"route";
1735 /* A router may return REROUTED if it has set up a child address as a result
1736 of a change of domain name (typically from widening). In this case we always
1737 want to continue to verify the new child. */
1739 if (rc == REROUTED) continue;
1741 /* Handle hard failures */
1748 address_item *p = addr->parent;
1750 respond_printf(f, "%s%s %s", ko_prefix,
1751 full_info? addr->address : address,
1752 address_test_mode? "is undeliverable" : "failed to verify");
1753 if (!expn && admin_user)
1755 if (addr->basic_errno > 0)
1756 respond_printf(f, ": %s", strerror(addr->basic_errno));
1757 if (addr->message != NULL)
1758 respond_printf(f, ": %s", addr->message);
1761 /* Show parents iff doing full info */
1763 if (full_info) while (p != NULL)
1765 respond_printf(f, "%s\n <-- %s", cr, p->address);
1768 respond_printf(f, "%s\n", cr);
1770 cancel_cutthrough_connection("routing hard fail");
1772 if (!full_info) return copy_error(vaddr, addr, FAIL);
1778 else if (rc == DEFER)
1783 address_item *p = addr->parent;
1784 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1785 full_info? addr->address : address);
1786 if (!expn && admin_user)
1788 if (addr->basic_errno > 0)
1789 respond_printf(f, ": %s", strerror(addr->basic_errno));
1790 if (addr->message != NULL)
1791 respond_printf(f, ": %s", addr->message);
1792 else if (addr->basic_errno <= 0)
1793 respond_printf(f, ": unknown error");
1796 /* Show parents iff doing full info */
1798 if (full_info) while (p != NULL)
1800 respond_printf(f, "%s\n <-- %s", cr, p->address);
1803 respond_printf(f, "%s\n", cr);
1805 cancel_cutthrough_connection("routing soft fail");
1807 if (!full_info) return copy_error(vaddr, addr, DEFER);
1808 else if (yield == OK) yield = DEFER;
1811 /* If we are handling EXPN, we do not want to continue to route beyond
1812 the top level (whose address is in "address"). */
1816 uschar *ok_prefix = US"250-";
1817 if (addr_new == NULL)
1819 if (addr_local == NULL && addr_remote == NULL)
1820 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1822 respond_printf(f, "250 <%s>\r\n", address);
1824 else while (addr_new != NULL)
1826 address_item *addr2 = addr_new;
1827 addr_new = addr2->next;
1828 if (addr_new == NULL) ok_prefix = US"250 ";
1829 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1834 /* Successful routing other than EXPN. */
1838 /* Handle successful routing when short info wanted. Otherwise continue for
1839 other (generated) addresses. Short info is the operational case. Full info
1840 can be requested only when debug_selector != 0 and a file is supplied.
1842 There is a conflict between the use of aliasing as an alternate email
1843 address, and as a sort of mailing list. If an alias turns the incoming
1844 address into just one address (e.g. J.Caesar->jc44) you may well want to
1845 carry on verifying the generated address to ensure it is valid when
1846 checking incoming mail. If aliasing generates multiple addresses, you
1847 probably don't want to do this. Exim therefore treats the generation of
1848 just a single new address as a special case, and continues on to verify the
1849 generated address. */
1851 if (!full_info && /* Stop if short info wanted AND */
1852 (((addr_new == NULL || /* No new address OR */
1853 addr_new->next != NULL || /* More than one new address OR */
1854 testflag(addr_new, af_pfr))) /* New address is pfr */
1856 (addr_new != NULL && /* At least one new address AND */
1857 success_on_redirect))) /* success_on_redirect is set */
1859 if (f != NULL) fprintf(f, "%s %s\n", address,
1860 address_test_mode? "is deliverable" : "verified");
1862 /* If we have carried on to verify a child address, we want the value
1863 of $address_data to be that of the child */
1865 vaddr->p.address_data = addr->p.address_data;
1869 } /* Loop for generated addresses */
1871 /* Display the full results of the successful routing, including any generated
1872 addresses. Control gets here only when full_info is set, which requires f not
1873 to be NULL, and this occurs only when a top-level verify is called with the
1874 debugging switch on.
1876 If there are no local and no remote addresses, and there were no pipes, files,
1877 or autoreplies, and there were no errors or deferments, the message is to be
1878 discarded, usually because of the use of :blackhole: in an alias file. */
1880 if (allok && addr_local == NULL && addr_remote == NULL)
1882 fprintf(f, "mail to %s is discarded\n", address);
1886 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1888 while (addr_list != NULL)
1890 address_item *addr = addr_list;
1891 address_item *p = addr->parent;
1892 addr_list = addr->next;
1894 fprintf(f, "%s", CS addr->address);
1895 #ifdef EXPERIMENTAL_SRS
1896 if(addr->p.srs_sender)
1897 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1900 /* If the address is a duplicate, show something about it. */
1902 if (!testflag(addr, af_pfr))
1905 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1906 fprintf(f, " [duplicate, would not be delivered]");
1907 else tree_add_duplicate(addr->unique, addr);
1910 /* Now show its parents */
1914 fprintf(f, "\n <-- %s", p->address);
1919 /* Show router, and transport */
1921 fprintf(f, "router = %s, ", addr->router->name);
1922 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1923 addr->transport->name);
1925 /* Show any hosts that are set up by a router unless the transport
1926 is going to override them; fiddle a bit to get a nice format. */
1928 if (addr->host_list != NULL && addr->transport != NULL &&
1929 !addr->transport->overrides_hosts)
1934 for (h = addr->host_list; h != NULL; h = h->next)
1936 int len = Ustrlen(h->name);
1937 if (len > maxlen) maxlen = len;
1938 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1939 if (len > maxaddlen) maxaddlen = len;
1941 for (h = addr->host_list; h != NULL; h = h->next)
1943 int len = Ustrlen(h->name);
1944 fprintf(f, " host %s ", h->name);
1945 while (len++ < maxlen) fprintf(f, " ");
1946 if (h->address != NULL)
1948 fprintf(f, "[%s] ", h->address);
1949 len = Ustrlen(h->address);
1951 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1953 fprintf(f, "[unknown] ");
1957 while (len++ < maxaddlen) fprintf(f," ");
1958 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1959 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1960 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1967 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1968 the -bv or -bt case). */
1976 /*************************************************
1977 * Check headers for syntax errors *
1978 *************************************************/
1980 /* This function checks those header lines that contain addresses, and verifies
1981 that all the addresses therein are syntactially correct.
1984 msgptr where to put an error message
1991 verify_check_headers(uschar **msgptr)
1997 for (h = header_list; h != NULL && yield == OK; h = h->next)
1999 if (h->type != htype_from &&
2000 h->type != htype_reply_to &&
2001 h->type != htype_sender &&
2002 h->type != htype_to &&
2003 h->type != htype_cc &&
2004 h->type != htype_bcc)
2007 colon = Ustrchr(h->text, ':');
2009 while (isspace(*s)) s++;
2011 /* Loop for multiple addresses in the header, enabling group syntax. Note
2012 that we have to reset this after the header has been scanned. */
2014 parse_allow_group = TRUE;
2018 uschar *ss = parse_find_address_end(s, FALSE);
2019 uschar *recipient, *errmess;
2020 int terminator = *ss;
2021 int start, end, domain;
2023 /* Temporarily terminate the string at this point, and extract the
2024 operative address within, allowing group syntax. */
2027 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2030 /* Permit an unqualified address only if the message is local, or if the
2031 sending host is configured to be permitted to send them. */
2033 if (recipient != NULL && domain == 0)
2035 if (h->type == htype_from || h->type == htype_sender)
2037 if (!allow_unqualified_sender) recipient = NULL;
2041 if (!allow_unqualified_recipient) recipient = NULL;
2043 if (recipient == NULL) errmess = US"unqualified address not permitted";
2046 /* It's an error if no address could be extracted, except for the special
2047 case of an empty address. */
2049 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2051 uschar *verb = US"is";
2056 /* Arrange not to include any white space at the end in the
2057 error message or the header name. */
2059 while (t > s && isspace(t[-1])) t--;
2060 while (tt > h->text && isspace(tt[-1])) tt--;
2062 /* Add the address that failed to the error message, since in a
2063 header with very many addresses it is sometimes hard to spot
2064 which one is at fault. However, limit the amount of address to
2065 quote - cases have been seen where, for example, a missing double
2066 quote in a humungous To: header creates an "address" that is longer
2067 than string_sprintf can handle. */
2076 *msgptr = string_printing(
2077 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2078 errmess, tt - h->text, h->text, verb, len, s));
2081 break; /* Out of address loop */
2084 /* Advance to the next address */
2086 s = ss + (terminator? 1:0);
2087 while (isspace(*s)) s++;
2088 } /* Next address */
2090 parse_allow_group = FALSE;
2091 parse_found_group = FALSE;
2092 } /* Next header unless yield has been set FALSE */
2099 /*************************************************
2100 * Check for blind recipients *
2101 *************************************************/
2103 /* This function checks that every (envelope) recipient is mentioned in either
2104 the To: or Cc: header lines, thus detecting blind carbon copies.
2106 There are two ways of scanning that could be used: either scan the header lines
2107 and tick off the recipients, or scan the recipients and check the header lines.
2108 The original proposed patch did the former, but I have chosen to do the latter,
2109 because (a) it requires no memory and (b) will use fewer resources when there
2110 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2113 Returns: OK if there are no blind recipients
2114 FAIL if there is at least one blind recipient
2118 verify_check_notblind(void)
2121 for (i = 0; i < recipients_count; i++)
2125 uschar *address = recipients_list[i].address;
2127 for (h = header_list; !found && h != NULL; h = h->next)
2131 if (h->type != htype_to && h->type != htype_cc) continue;
2133 colon = Ustrchr(h->text, ':');
2135 while (isspace(*s)) s++;
2137 /* Loop for multiple addresses in the header, enabling group syntax. Note
2138 that we have to reset this after the header has been scanned. */
2140 parse_allow_group = TRUE;
2144 uschar *ss = parse_find_address_end(s, FALSE);
2145 uschar *recipient,*errmess;
2146 int terminator = *ss;
2147 int start, end, domain;
2149 /* Temporarily terminate the string at this point, and extract the
2150 operative address within, allowing group syntax. */
2153 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2156 /* If we found a valid recipient that has a domain, compare it with the
2157 envelope recipient. Local parts are compared case-sensitively, domains
2158 case-insensitively. By comparing from the start with length "domain", we
2159 include the "@" at the end, which ensures that we are comparing the whole
2160 local part of each address. */
2162 if (recipient != NULL && domain != 0)
2164 found = Ustrncmp(recipient, address, domain) == 0 &&
2165 strcmpic(recipient + domain, address + domain) == 0;
2169 /* Advance to the next address */
2171 s = ss + (terminator? 1:0);
2172 while (isspace(*s)) s++;
2173 } /* Next address */
2175 parse_allow_group = FALSE;
2176 parse_found_group = FALSE;
2177 } /* Next header (if found is false) */
2179 if (!found) return FAIL;
2180 } /* Next recipient */
2187 /*************************************************
2188 * Find if verified sender *
2189 *************************************************/
2191 /* Usually, just a single address is verified as the sender of the message.
2192 However, Exim can be made to verify other addresses as well (often related in
2193 some way), and this is useful in some environments. There may therefore be a
2194 chain of such addresses that have previously been tested. This function finds
2195 whether a given address is on the chain.
2197 Arguments: the address to be verified
2198 Returns: pointer to an address item, or NULL
2202 verify_checked_sender(uschar *sender)
2205 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2206 if (Ustrcmp(sender, addr->address) == 0) break;
2214 /*************************************************
2215 * Get valid header address *
2216 *************************************************/
2218 /* Scan the originator headers of the message, looking for an address that
2219 verifies successfully. RFC 822 says:
2221 o The "Sender" field mailbox should be sent notices of
2222 any problems in transport or delivery of the original
2223 messages. If there is no "Sender" field, then the
2224 "From" field mailbox should be used.
2226 o If the "Reply-To" field exists, then the reply should
2227 go to the addresses indicated in that field and not to
2228 the address(es) indicated in the "From" field.
2230 So we check a Sender field if there is one, else a Reply_to field, else a From
2231 field. As some strange messages may have more than one of these fields,
2232 especially if they are resent- fields, check all of them if there is more than
2236 user_msgptr points to where to put a user error message
2237 log_msgptr points to where to put a log error message
2238 callout timeout for callout check (passed to verify_address())
2239 callout_overall overall callout timeout (ditto)
2240 callout_connect connect callout timeout (ditto)
2241 se_mailfrom mailfrom for verify; NULL => ""
2242 pm_mailfrom sender for pm callout check (passed to verify_address())
2243 options callout options (passed to verify_address())
2244 verrno where to put the address basic_errno
2246 If log_msgptr is set to something without setting user_msgptr, the caller
2247 normally uses log_msgptr for both things.
2249 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2250 FAIL is given if no appropriate headers are found
2254 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2255 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2256 uschar *pm_mailfrom, int options, int *verrno)
2258 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2263 for (i = 0; i < 3 && !done; i++)
2266 for (h = header_list; h != NULL && !done; h = h->next)
2268 int terminator, new_ok;
2269 uschar *s, *ss, *endname;
2271 if (h->type != header_types[i]) continue;
2272 s = endname = Ustrchr(h->text, ':') + 1;
2274 /* Scan the addresses in the header, enabling group syntax. Note that we
2275 have to reset this after the header has been scanned. */
2277 parse_allow_group = TRUE;
2281 address_item *vaddr;
2283 while (isspace(*s) || *s == ',') s++;
2284 if (*s == 0) break; /* End of header */
2286 ss = parse_find_address_end(s, FALSE);
2288 /* The terminator is a comma or end of header, but there may be white
2289 space preceding it (including newline for the last address). Move back
2290 past any white space so we can check against any cached envelope sender
2291 address verifications. */
2293 while (isspace(ss[-1])) ss--;
2297 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2298 (int)(endname - h->text), h->text, s);
2300 /* See if we have already verified this address as an envelope sender,
2301 and if so, use the previous answer. */
2303 vaddr = verify_checked_sender(s);
2305 if (vaddr != NULL && /* Previously checked */
2306 (callout <= 0 || /* No callout needed; OR */
2307 vaddr->special_action > 256)) /* Callout was done */
2309 new_ok = vaddr->special_action & 255;
2310 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2311 *ss = terminator; /* Restore shortened string */
2314 /* Otherwise we run the verification now. We must restore the shortened
2315 string before running the verification, so the headers are correct, in
2316 case there is any rewriting. */
2320 int start, end, domain;
2321 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2326 /* If we found an empty address, just carry on with the next one, but
2327 kill the message. */
2329 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2336 /* If verification failed because of a syntax error, fail this
2337 function, and ensure that the failing address gets added to the error
2340 if (address == NULL)
2343 while (ss > s && isspace(ss[-1])) ss--;
2344 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2345 "scanning for sender: %s in \"%.*s\"",
2346 endname - h->text, h->text, *log_msgptr, ss - s, s);
2352 /* Else go ahead with the sender verification. But it isn't *the*
2353 sender of the message, so set vopt_fake_sender to stop sender_address
2354 being replaced after rewriting or qualification. */
2358 vaddr = deliver_make_addr(address, FALSE);
2359 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2360 callout, callout_overall, callout_connect, se_mailfrom,
2365 /* We now have the result, either newly found, or cached. If we are
2366 giving out error details, set a specific user error. This means that the
2367 last of these will be returned to the user if all three fail. We do not
2368 set a log message - the generic one below will be used. */
2372 *verrno = vaddr->basic_errno;
2373 if (smtp_return_error_details)
2375 *user_msgptr = string_sprintf("Rejected after DATA: "
2376 "could not verify \"%.*s\" header address\n%s: %s",
2377 endname - h->text, h->text, vaddr->address, vaddr->message);
2381 /* Success or defer */
2390 if (new_ok == DEFER) yield = DEFER;
2392 /* Move on to any more addresses in the header */
2395 } /* Next address */
2397 parse_allow_group = FALSE;
2398 parse_found_group = FALSE;
2399 } /* Next header, unless done */
2400 } /* Next header type unless done */
2402 if (yield == FAIL && *log_msgptr == NULL)
2403 *log_msgptr = US"there is no valid sender in any header line";
2405 if (yield == DEFER && *log_msgptr == NULL)
2406 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2414 /*************************************************
2415 * Get RFC 1413 identification *
2416 *************************************************/
2418 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2419 the timeout is set to zero, then the query is not done. There may also be lists
2420 of hosts and nets which are exempt. To guard against malefactors sending
2421 non-printing characters which could, for example, disrupt a message's headers,
2422 make sure the string consists of printing characters only.
2425 port the port to connect to; usually this is IDENT_PORT (113), but when
2426 running in the test harness with -bh a different value is used.
2430 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2434 verify_get_ident(int port)
2436 int sock, host_af, qlen;
2437 int received_sender_port, received_interface_port, n;
2439 uschar buffer[2048];
2441 /* Default is no ident. Check whether we want to do an ident check for this
2444 sender_ident = NULL;
2445 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2448 DEBUG(D_ident) debug_printf("doing ident callback\n");
2450 /* Set up a connection to the ident port of the remote host. Bind the local end
2451 to the incoming interface address. If the sender host address is an IPv6
2452 address, the incoming interface address will also be IPv6. */
2454 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2455 sock = ip_socket(SOCK_STREAM, host_af);
2456 if (sock < 0) return;
2458 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2460 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2465 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2468 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2470 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2471 sender_host_address);
2475 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2476 sender_host_address, strerror(errno));
2481 /* Construct and send the query. */
2483 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2484 qlen = Ustrlen(buffer);
2485 if (send(sock, buffer, qlen, 0) < 0)
2487 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2491 /* Read a response line. We put it into the rest of the buffer, using several
2492 recv() calls if necessary. */
2500 int size = sizeof(buffer) - (p - buffer);
2502 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2503 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2504 if (count <= 0) goto END_OFF; /* Read error or EOF */
2506 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2507 generous, and accept a plain \n terminator as well. The only illegal
2510 for (pp = p; pp < p + count; pp++)
2512 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2515 if (pp[-1] == '\r') pp--;
2517 goto GOT_DATA; /* Break out of both loops */
2521 /* Reached the end of the data without finding \n. Let the loop continue to
2522 read some more, if there is room. */
2529 /* We have received a line of data. Check it carefully. It must start with the
2530 same two port numbers that we sent, followed by data as defined by the RFC. For
2533 12345 , 25 : USERID : UNIX :root
2535 However, the amount of white space may be different to what we sent. In the
2536 "osname" field there may be several sub-fields, comma separated. The data we
2537 actually want to save follows the third colon. Some systems put leading spaces
2538 in it - we discard those. */
2540 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2541 &received_interface_port, &n) != 2 ||
2542 received_sender_port != sender_host_port ||
2543 received_interface_port != interface_port)
2546 p = buffer + qlen + n;
2547 while(isspace(*p)) p++;
2548 if (*p++ != ':') goto END_OFF;
2549 while(isspace(*p)) p++;
2550 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2552 while(isspace(*p)) p++;
2553 if (*p++ != ':') goto END_OFF;
2554 while (*p != 0 && *p != ':') p++;
2555 if (*p++ == 0) goto END_OFF;
2556 while(isspace(*p)) p++;
2557 if (*p == 0) goto END_OFF;
2559 /* The rest of the line is the data we want. We turn it into printing
2560 characters when we save it, so that it cannot mess up the format of any logging
2561 or Received: lines into which it gets inserted. We keep a maximum of 127
2564 sender_ident = string_printing(string_copyn(p, 127));
2565 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2575 /*************************************************
2576 * Match host to a single host-list item *
2577 *************************************************/
2579 /* This function compares a host (name or address) against a single item
2580 from a host list. The host name gets looked up if it is needed and is not
2581 already known. The function is called from verify_check_this_host() via
2582 match_check_list(), which is why most of its arguments are in a single block.
2585 arg the argument block (see below)
2586 ss the host-list item
2587 valueptr where to pass back looked up data, or NULL
2588 error for error message when returning ERROR
2591 host_name (a) the host name, or
2592 (b) NULL, implying use sender_host_name and
2593 sender_host_aliases, looking them up if required, or
2594 (c) the empty string, meaning that only IP address matches
2596 host_address the host address
2597 host_ipv4 the IPv4 address taken from an IPv6 one
2601 DEFER lookup deferred
2602 ERROR (a) failed to find the host name or IP address, or
2603 (b) unknown lookup type specified, or
2604 (c) host name encountered when only IP addresses are
2609 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2611 check_host_block *cb = (check_host_block *)arg;
2614 BOOL iplookup = FALSE;
2615 BOOL isquery = FALSE;
2616 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2621 /* Optimize for the special case when the pattern is "*". */
2623 if (*ss == '*' && ss[1] == 0) return OK;
2625 /* If the pattern is empty, it matches only in the case when there is no host -
2626 this can occur in ACL checking for SMTP input using the -bs option. In this
2627 situation, the host address is the empty string. */
2629 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2630 if (*ss == 0) return FAIL;
2632 /* If the pattern is precisely "@" then match against the primary host name,
2633 provided that host name matching is permitted; if it's "@[]" match against the
2634 local host's IP addresses. */
2640 if (isiponly) return ERROR;
2641 ss = primary_hostname;
2643 else if (Ustrcmp(ss, "@[]") == 0)
2645 ip_address_item *ip;
2646 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2647 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2652 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2653 a (possibly masked) comparision with the current IP address. */
2655 if (string_is_ip_address(ss, &maskoffset) != 0)
2656 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2658 /* The pattern is not an IP address. A common error that people make is to omit
2659 one component of an IPv4 address, either by accident, or believing that, for
2660 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,
2661 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2662 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2663 ancient specification.) To aid in debugging these cases, we give a specific
2664 error if the pattern contains only digits and dots or contains a slash preceded
2665 only by digits and dots (a slash at the start indicates a file name and of
2666 course slashes may be present in lookups, but not preceded only by digits and
2669 for (t = ss; isdigit(*t) || *t == '.'; t++);
2670 if (*t == 0 || (*t == '/' && t != ss))
2672 *error = US"malformed IPv4 address or address mask";
2676 /* See if there is a semicolon in the pattern */
2678 semicolon = Ustrchr(ss, ';');
2680 /* If we are doing an IP address only match, then all lookups must be IP
2681 address lookups, even if there is no "net-". */
2685 iplookup = semicolon != NULL;
2688 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2689 a lookup on a masked IP network, in textual form. We obey this code even if we
2690 have already set iplookup, so as to skip over the "net-" prefix and to set the
2691 mask length. The net- stuff really only applies to single-key lookups where the
2692 key is implicit. For query-style lookups the key is specified in the query.
2693 From release 4.30, the use of net- for query style is no longer needed, but we
2694 retain it for backward compatibility. */
2696 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2699 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2700 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2701 iplookup = (*t++ == '-');
2705 /* Do the IP address lookup if that is indeed what we have */
2713 uschar *filename, *key, *result;
2716 /* Find the search type */
2718 search_type = search_findtype(t, semicolon - t);
2720 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2721 search_error_message);
2723 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2724 is no file name, and the "key" is just the query. For query-style with a file
2725 name, we have to fish the file off the start of the query. For a single-key
2726 lookup, the key is the current IP address, masked appropriately, and
2727 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2728 dot separators instead of colons, except when the lookup type is "iplsearch".
2731 if (mac_islookup(search_type, lookup_absfilequery))
2733 filename = semicolon + 1;
2735 while (*key != 0 && !isspace(*key)) key++;
2736 filename = string_copyn(filename, key - filename);
2737 while (isspace(*key)) key++;
2739 else if (mac_islookup(search_type, lookup_querystyle))
2742 key = semicolon + 1;
2744 else /* Single-key style */
2746 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2748 insize = host_aton(cb->host_address, incoming);
2749 host_mask(insize, incoming, mlen);
2750 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2752 filename = semicolon + 1;
2755 /* Now do the actual lookup; note that there is no search_close() because
2756 of the caching arrangements. */
2758 handle = search_open(filename, search_type, 0, NULL, NULL);
2759 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2760 search_error_message);
2761 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2762 if (valueptr != NULL) *valueptr = result;
2763 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2766 /* The pattern is not an IP address or network reference of any kind. That is,
2767 it is a host name pattern. If this is an IP only match, there's an error in the
2772 *error = US"cannot match host name in match_ip list";
2776 /* Check the characters of the pattern to see if they comprise only letters,
2777 digits, full stops, and hyphens (the constituents of domain names). Allow
2778 underscores, as they are all too commonly found. Sigh. Also, if
2779 allow_utf8_domains is set, allow top-bit characters. */
2781 for (t = ss; *t != 0; t++)
2782 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2783 (!allow_utf8_domains || *t < 128)) break;
2785 /* If the pattern is a complete domain name, with no fancy characters, look up
2786 its IP address and match against that. Note that a multi-homed host will add
2787 items to the chain. */
2798 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2799 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2802 for (hh = &h; hh != NULL; hh = hh->next)
2804 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2808 if (rc == HOST_FIND_AGAIN) return DEFER;
2809 *error = string_sprintf("failed to find IP address for %s", ss);
2813 /* Almost all subsequent comparisons require the host name, and can be done
2814 using the general string matching function. When this function is called for
2815 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2816 must use sender_host_name and its aliases, looking them up if necessary. */
2818 if (cb->host_name != NULL) /* Explicit host name given */
2819 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2822 /* Host name not given; in principle we need the sender host name and its
2823 aliases. However, for query-style lookups, we do not need the name if the
2824 query does not contain $sender_host_name. From release 4.23, a reference to
2825 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2828 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2831 int partial, affixlen, starflags, id;
2834 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2837 if (id < 0) /* Unknown lookup type */
2839 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2840 search_error_message, ss);
2843 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2848 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2851 case DEFER: return DEFER;
2852 default: return FAIL;
2856 /* Not a query-style lookup; must ensure the host name is present, and then we
2857 do a check on the name and all its aliases. */
2859 if (sender_host_name == NULL)
2861 HDEBUG(D_host_lookup)
2862 debug_printf("sender host name required, to match against %s\n", ss);
2863 if (host_lookup_failed || host_name_lookup() != OK)
2865 *error = string_sprintf("failed to find host name for %s",
2866 sender_host_address);;
2869 host_build_sender_fullhost();
2872 /* Match on the sender host name, using the general matching function */
2874 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2878 case DEFER: return DEFER;
2881 /* If there are aliases, try matching on them. */
2883 aliases = sender_host_aliases;
2884 while (*aliases != NULL)
2886 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2889 case DEFER: return DEFER;
2898 /*************************************************
2899 * Check a specific host matches a host list *
2900 *************************************************/
2902 /* This function is passed a host list containing items in a number of
2903 different formats and the identity of a host. Its job is to determine whether
2904 the given host is in the set of hosts defined by the list. The host name is
2905 passed as a pointer so that it can be looked up if needed and not already
2906 known. This is commonly the case when called from verify_check_host() to check
2907 an incoming connection. When called from elsewhere the host name should usually
2910 This function is now just a front end to match_check_list(), which runs common
2911 code for scanning a list. We pass it the check_host() function to perform a
2915 listptr pointer to the host list
2916 cache_bits pointer to cache for named lists, or NULL
2917 host_name the host name or NULL, implying use sender_host_name and
2918 sender_host_aliases, looking them up if required
2919 host_address the IP address
2920 valueptr if not NULL, data from a lookup is passed back here
2922 Returns: OK if the host is in the defined set
2923 FAIL if the host is not in the defined set,
2924 DEFER if a data lookup deferred (not a host lookup)
2926 If the host name was needed in order to make a comparison, and could not be
2927 determined from the IP address, the result is FAIL unless the item
2928 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2931 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2932 uschar *host_name, uschar *host_address, uschar **valueptr)
2935 unsigned int *local_cache_bits = cache_bits;
2936 uschar *save_host_address = deliver_host_address;
2937 check_host_block cb;
2938 cb.host_name = host_name;
2939 cb.host_address = host_address;
2941 if (valueptr != NULL) *valueptr = NULL;
2943 /* If the host address starts off ::ffff: it is an IPv6 address in
2944 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2947 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2948 host_address + 7 : host_address;
2950 /* During the running of the check, put the IP address into $host_address. In
2951 the case of calls from the smtp transport, it will already be there. However,
2952 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2953 the safe side, any existing setting is preserved, though as I write this
2954 (November 2004) I can't see any cases where it is actually needed. */
2956 deliver_host_address = host_address;
2957 rc = match_check_list(
2958 listptr, /* the list */
2959 0, /* separator character */
2960 &hostlist_anchor, /* anchor pointer */
2961 &local_cache_bits, /* cache pointer */
2962 check_host, /* function for testing */
2963 &cb, /* argument for function */
2964 MCL_HOST, /* type of check */
2965 (host_address == sender_host_address)?
2966 US"host" : host_address, /* text for debugging */
2967 valueptr); /* where to pass back data */
2968 deliver_host_address = save_host_address;
2975 /*************************************************
2976 * Check the remote host matches a list *
2977 *************************************************/
2979 /* This is a front end to verify_check_this_host(), created because checking
2980 the remote host is a common occurrence. With luck, a good compiler will spot
2981 the tail recursion and optimize it. If there's no host address, this is
2982 command-line SMTP input - check against an empty string for the address.
2985 listptr pointer to the host list
2987 Returns: the yield of verify_check_this_host(),
2988 i.e. OK, FAIL, or DEFER
2992 verify_check_host(uschar **listptr)
2994 return verify_check_this_host(listptr, sender_host_cache, NULL,
2995 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3002 /*************************************************
3003 * Invert an IP address *
3004 *************************************************/
3006 /* Originally just used for DNS xBL lists, now also used for the
3007 reverse_ip expansion operator.
3010 buffer where to put the answer
3011 address the address to invert
3015 invert_address(uschar *buffer, uschar *address)
3018 uschar *bptr = buffer;
3020 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3021 to the IPv4 part only. */
3023 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3025 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3028 if (host_aton(address, bin) == 1)
3032 for (i = 0; i < 4; i++)
3034 sprintf(CS bptr, "%d.", x & 255);
3035 while (*bptr) bptr++;
3040 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3041 in any DNS black lists, and the format in which they will be looked up is
3042 unknown. This is just a guess. */
3048 for (j = 3; j >= 0; j--)
3051 for (i = 0; i < 8; i++)
3053 sprintf(CS bptr, "%x.", x & 15);
3054 while (*bptr) bptr++;
3061 /* Remove trailing period -- this is needed so that both arbitrary
3062 dnsbl keydomains and inverted addresses may be combined with the
3063 same format string, "%s.%s" */
3070 /*************************************************
3071 * Perform a single dnsbl lookup *
3072 *************************************************/
3074 /* This function is called from verify_check_dnsbl() below. It is also called
3075 recursively from within itself when domain and domain_txt are different
3076 pointers, in order to get the TXT record from the alternate domain.
3079 domain the outer dnsbl domain
3080 domain_txt alternate domain to lookup TXT record on success; when the
3081 same domain is to be used, domain_txt == domain (that is,
3082 the pointers must be identical, not just the text)
3083 keydomain the current keydomain (for debug message)
3084 prepend subdomain to lookup (like keydomain, but
3085 reversed if IP address)
3086 iplist the list of matching IP addresses, or NULL for "any"
3087 bitmask true if bitmask matching is wanted
3088 match_type condition for 'succeed' result
3089 0 => Any RR in iplist (=)
3090 1 => No RR in iplist (!=)
3091 2 => All RRs in iplist (==)
3092 3 => Some RRs not in iplist (!==)
3093 the two bits are defined as MT_NOT and MT_ALL
3094 defer_return what to return for a defer
3096 Returns: OK if lookup succeeded
3101 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3102 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3108 dnsbl_cache_block *cb;
3109 int old_pool = store_pool;
3110 uschar query[256]; /* DNS domain max length */
3112 /* Construct the specific query domainname */
3114 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3116 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3117 "(ignored): %s...", query);
3121 /* Look for this query in the cache. */
3123 t = tree_search(dnsbl_cache, query);
3125 /* If not cached from a previous lookup, we must do a DNS lookup, and
3126 cache the result in permanent memory. */
3130 store_pool = POOL_PERM;
3132 /* Set up a tree entry to cache the lookup */
3134 t = store_get(sizeof(tree_node) + Ustrlen(query));
3135 Ustrcpy(t->name, query);
3136 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3137 (void)tree_insertnode(&dnsbl_cache, t);
3139 /* Do the DNS loopup . */
3141 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3142 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3143 cb->text_set = FALSE;
3147 /* If the lookup succeeded, cache the RHS address. The code allows for
3148 more than one address - this was for complete generality and the possible
3149 use of A6 records. However, A6 records have been reduced to experimental
3150 status (August 2001) and may die out. So they may never get used at all,
3151 let alone in dnsbl records. However, leave the code here, just in case.
3153 Quite apart from one A6 RR generating multiple addresses, there are DNS
3154 lists that return more than one A record, so we must handle multiple
3155 addresses generated in that way as well. */
3157 if (cb->rc == DNS_SUCCEED)
3160 dns_address **addrp = &(cb->rhs);
3161 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3163 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3165 if (rr->type == T_A)
3167 dns_address *da = dns_address_from_rr(&dnsa, rr);
3171 while (da->next != NULL) da = da->next;
3172 addrp = &(da->next);
3177 /* If we didn't find any A records, change the return code. This can
3178 happen when there is a CNAME record but there are no A records for what
3181 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3184 store_pool = old_pool;
3187 /* Previous lookup was cached */
3191 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3195 /* We now have the result of the DNS lookup, either newly done, or cached
3196 from a previous call. If the lookup succeeded, check against the address
3197 list if there is one. This may be a positive equality list (introduced by
3198 "="), a negative equality list (introduced by "!="), a positive bitmask
3199 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3201 if (cb->rc == DNS_SUCCEED)
3203 dns_address *da = NULL;
3204 uschar *addlist = cb->rhs->address;
3206 /* For A and AAAA records, there may be multiple addresses from multiple
3207 records. For A6 records (currently not expected to be used) there may be
3208 multiple addresses from a single record. */
3210 for (da = cb->rhs->next; da != NULL; da = da->next)
3211 addlist = string_sprintf("%s, %s", addlist, da->address);
3213 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3216 /* Address list check; this can be either for equality, or via a bitmask.
3217 In the latter case, all the bits must match. */
3221 for (da = cb->rhs; da != NULL; da = da->next)
3225 uschar *ptr = iplist;
3228 /* Handle exact matching */
3232 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3234 if (Ustrcmp(CS da->address, ip) == 0) break;
3238 /* Handle bitmask matching */
3245 /* At present, all known DNS blocking lists use A records, with
3246 IPv4 addresses on the RHS encoding the information they return. I
3247 wonder if this will linger on as the last vestige of IPv4 when IPv6
3248 is ubiquitous? Anyway, for now we use paranoia code to completely
3249 ignore IPv6 addresses. The default mask is 0, which always matches.
3250 We change this only for IPv4 addresses in the list. */
3252 if (host_aton(da->address, address) == 1) mask = address[0];
3254 /* Scan the returned addresses, skipping any that are IPv6 */
3256 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3258 if (host_aton(ip, address) != 1) continue;
3259 if ((address[0] & mask) == address[0]) break;
3265 (a) An IP address in an any ('=') list matched, or
3266 (b) No IP address in an all ('==') list matched
3268 then we're done searching. */
3270 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3273 /* If da == NULL, either
3275 (a) No IP address in an any ('=') list matched, or
3276 (b) An IP address in an all ('==') list didn't match
3278 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3281 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3289 res = US"was no match";
3292 res = US"was an exclude match";
3295 res = US"was an IP address that did not match";
3298 res = US"were no IP addresses that did not match";
3301 debug_printf("=> but we are not accepting this block class because\n");
3302 debug_printf("=> there %s for %s%c%s\n",
3304 ((match_type & MT_ALL) == 0)? "" : "=",
3305 bitmask? '&' : '=', iplist);
3311 /* Either there was no IP list, or the record matched, implying that the
3312 domain is on the list. We now want to find a corresponding TXT record. If an
3313 alternate domain is specified for the TXT record, call this function
3314 recursively to look that up; this has the side effect of re-checking that
3315 there is indeed an A record at the alternate domain. */
3317 if (domain_txt != domain)
3318 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3319 FALSE, match_type, defer_return);
3321 /* If there is no alternate domain, look up a TXT record in the main domain
3322 if it has not previously been cached. */
3326 cb->text_set = TRUE;
3327 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3330 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3332 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3333 if (rr->type == T_TXT) break;
3336 int len = (rr->data)[0];
3337 if (len > 511) len = 127;
3338 store_pool = POOL_PERM;
3339 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3340 store_pool = old_pool;
3345 dnslist_value = addlist;
3346 dnslist_text = cb->text;
3350 /* There was a problem with the DNS lookup */
3352 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3354 log_write(L_dnslist_defer, LOG_MAIN,
3355 "DNS list lookup defer (probably timeout) for %s: %s", query,
3356 (defer_return == OK)? US"assumed in list" :
3357 (defer_return == FAIL)? US"assumed not in list" :
3358 US"returned DEFER");
3359 return defer_return;
3362 /* No entry was found in the DNS; continue for next domain */
3366 debug_printf("DNS lookup for %s failed\n", query);
3367 debug_printf("=> that means %s is not listed at %s\n",
3377 /*************************************************
3378 * Check host against DNS black lists *
3379 *************************************************/
3381 /* This function runs checks against a list of DNS black lists, until one
3382 matches. Each item on the list can be of the form
3384 domain=ip-address/key
3386 The domain is the right-most domain that is used for the query, for example,
3387 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3388 if the DNS lookup returns a matching IP address. Several addresses may be
3389 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3391 If no key is given, what is looked up in the domain is the inverted IP address
3392 of the current client host. If a key is given, it is used to construct the
3393 domain for the lookup. For example:
3395 dsn.rfc-ignorant.org/$sender_address_domain
3397 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3398 then we check for a TXT record for an error message, and if found, save its
3399 value in $dnslist_text. We also cache everything in a tree, to optimize
3402 The TXT record is normally looked up in the same domain as the A record, but
3403 when many lists are combined in a single DNS domain, this will not be a very
3404 specific message. It is possible to specify a different domain for looking up
3405 TXT records; this is given before the main domain, comma-separated. For
3408 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3409 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3411 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3413 Note: an address for testing RBL is 192.203.178.39
3414 Note: an address for testing DUL is 192.203.178.4
3415 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3418 listptr the domain/address/data list
3420 Returns: OK successful lookup (i.e. the address is on the list), or
3421 lookup deferred after +include_unknown
3422 FAIL name not found, or no data found for the given type, or
3423 lookup deferred after +exclude_unknown (default)
3424 DEFER lookup failure, if +defer_unknown was set
3428 verify_check_dnsbl(uschar **listptr)
3431 int defer_return = FAIL;
3432 uschar *list = *listptr;
3435 uschar buffer[1024];
3436 uschar revadd[128]; /* Long enough for IPv6 address */
3438 /* Indicate that the inverted IP address is not yet set up */
3442 /* In case this is the first time the DNS resolver is being used. */
3444 dns_init(FALSE, FALSE);
3446 /* Loop through all the domains supplied, until something matches */
3448 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3451 BOOL bitmask = FALSE;
3458 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3460 /* Deal with special values that change the behaviour on defer */
3462 if (domain[0] == '+')
3464 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3465 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3466 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3468 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3473 /* See if there's explicit data to be looked up */
3475 key = Ustrchr(domain, '/');
3476 if (key != NULL) *key++ = 0;
3478 /* See if there's a list of addresses supplied after the domain name. This is
3479 introduced by an = or a & character; if preceded by = we require all matches
3480 and if preceded by ! we invert the result. */
3482 iplist = Ustrchr(domain, '=');
3486 iplist = Ustrchr(domain, '&');
3489 if (iplist != NULL) /* Found either = or & */
3491 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3493 match_type |= MT_NOT;
3497 *iplist++ = 0; /* Terminate domain, move on */
3499 /* If we found = (bitmask == FALSE), check for == or =& */
3501 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3503 bitmask = *iplist++ == '&';
3504 match_type |= MT_ALL;
3508 /* If there is a comma in the domain, it indicates that a second domain for
3509 looking up TXT records is provided, before the main domain. Otherwise we must
3510 set domain_txt == domain. */
3512 domain_txt = domain;
3513 comma = Ustrchr(domain, ',');
3520 /* Check that what we have left is a sensible domain name. There is no reason
3521 why these domains should in fact use the same syntax as hosts and email
3522 domains, but in practice they seem to. However, there is little point in
3523 actually causing an error here, because that would no doubt hold up incoming
3524 mail. Instead, I'll just log it. */
3526 for (s = domain; *s != 0; s++)
3528 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3530 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3531 "strange characters - is this right?", domain);
3536 /* Check the alternate domain if present */
3538 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3540 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3542 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3543 "strange characters - is this right?", domain_txt);
3548 /* If there is no key string, construct the query by adding the domain name
3549 onto the inverted host address, and perform a single DNS lookup. */
3553 if (sender_host_address == NULL) return FAIL; /* can never match */
3554 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3555 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3556 iplist, bitmask, match_type, defer_return);
3559 dnslist_domain = string_copy(domain_txt);
3560 dnslist_matched = string_copy(sender_host_address);
3561 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3562 sender_host_address, dnslist_domain);
3564 if (rc != FAIL) return rc; /* OK or DEFER */
3567 /* If there is a key string, it can be a list of domains or IP addresses to
3568 be concatenated with the main domain. */
3575 uschar keybuffer[256];
3576 uschar keyrevadd[128];
3578 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3579 sizeof(keybuffer))) != NULL)
3581 uschar *prepend = keydomain;
3583 if (string_is_ip_address(keydomain, NULL) != 0)
3585 invert_address(keyrevadd, keydomain);
3586 prepend = keyrevadd;
3589 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3590 bitmask, match_type, defer_return);
3594 dnslist_domain = string_copy(domain_txt);
3595 dnslist_matched = string_copy(keydomain);
3596 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3597 keydomain, dnslist_domain);
3601 /* If the lookup deferred, remember this fact. We keep trying the rest
3602 of the list to see if we get a useful result, and if we don't, we return
3603 DEFER at the end. */
3605 if (rc == DEFER) defer = TRUE;
3606 } /* continue with next keystring domain/address */
3608 if (defer) return DEFER;
3610 } /* continue with next dnsdb outer domain */
3615 /* End of verify.c */