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);
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)
606 uschar buffer2[4096];
608 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
611 /* If there is an I/O error, transmission of this message is deferred. If
612 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
613 false, we also defer. However, if there is a temporary rejection of STARTTLS
614 and tls_tempfail_tryclear is true, or if there is an outright rejection of
615 STARTTLS, we carry on. This means we will try to send the message in clear,
616 unless the host is in hosts_require_tls (tested below). */
618 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
619 ob->command_timeout))
621 if (errno != 0 || buffer2[0] == 0 ||
622 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
624 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
626 goto RESPONSE_FAILED;
630 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
633 int rc = tls_client_start(inblock.sock, host, addr,
634 NULL, /* No DH param */
635 ob->tls_certificate, ob->tls_privatekey,
637 ob->tls_verify_certificates, ob->tls_crl,
638 ob->tls_require_ciphers,
639 ob->gnutls_require_mac, ob->gnutls_require_kx, ob->gnutls_require_proto,
642 /* TLS negotiation failed; give an error. Try in clear on a new connection,
643 if the options permit it for this host. */
646 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
647 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
648 host->address, NULL) != OK)
650 (void)close(inblock.sock);
651 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
652 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
654 goto tls_retry_connection;
656 /*save_errno = ERRNO_TLSFAILURE;*/
657 /*message = US"failure while setting up TLS session";*/
663 /* TLS session is set up. Copy info for logging. */
664 addr->cipher = tls_out.cipher;
665 addr->peerdn = tls_out.peerdn;
667 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
669 goto smtps_redo_greeting;
671 /* For STARTTLS we need to redo EHLO */
676 /* If the host is required to use a secure channel, ensure that we have one. */
677 if (tls_out.active < 0)
678 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
679 host->address, NULL) == OK)
681 /*save_errno = ERRNO_TLSREQUIRED;*/
682 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
683 host->name, host->address,
684 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
689 #endif /*SUPPORT_TLS*/
691 done = TRUE; /* so far so good; have response to HELO */
693 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING, AUTH */
694 /* If we haven't authenticated, but are required to, give up. */
696 /*XXX "filter command specified for this transport" ??? */
697 /* for now, transport_filter by cutthrough-delivery is not supported */
698 /* Need proper integration with the proper transport mechanism. */
705 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
708 /* Failure to accept HELO is cached; this blocks the whole domain for all
709 senders. I/O errors and defer responses are not cached. */
713 *failure_ptr = US"mail"; /* At or before MAIL */
714 if (errno == 0 && responsebuffer[0] == '5')
716 setflag(addr, af_verify_nsfail);
717 new_domain_record.result = ccache_reject;
721 /* Send the MAIL command */
724 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
725 from_address) >= 0 &&
726 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
729 /* If the host does not accept MAIL FROM:<>, arrange to cache this
730 information, but again, don't record anything for an I/O error or a defer. Do
731 not cache rejections of MAIL when a non-empty sender has been used, because
732 that blocks the whole domain for all senders. */
736 *failure_ptr = US"mail"; /* At or before MAIL */
737 if (errno == 0 && responsebuffer[0] == '5')
739 setflag(addr, af_verify_nsfail);
740 if (from_address[0] == 0)
741 new_domain_record.result = ccache_reject_mfnull;
745 /* Otherwise, proceed to check a "random" address (if required), then the
746 given address, and the postmaster address (if required). Between each check,
747 issue RSET, because some servers accept only one recipient after MAIL
750 Before doing this, set the result in the domain cache record to "accept",
751 unless its previous value was ccache_reject_mfnull. In that case, the domain
752 rejects MAIL FROM:<> and we want to continue to remember that. When that is
753 the case, we have got here only in the case of a recipient verification with
754 a non-null sender. */
758 new_domain_record.result =
759 (old_domain_cache_result == ccache_reject_mfnull)?
760 ccache_reject_mfnull: ccache_accept;
762 /* Do the random local part check first */
764 if (random_local_part != NULL)
766 uschar randombuffer[1024];
768 smtp_write_command(&outblock, FALSE,
769 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
770 addr->domain) >= 0 &&
771 smtp_read_response(&inblock, randombuffer,
772 sizeof(randombuffer), '2', callout);
774 /* Remember when we last did a random test */
776 new_domain_record.random_stamp = time(NULL);
778 /* If accepted, we aren't going to do any further tests below. */
782 new_domain_record.random_result = ccache_accept;
785 /* Otherwise, cache a real negative response, and get back to the right
786 state to send RCPT. Unless there's some problem such as a dropped
787 connection, we expect to succeed, because the commands succeeded above. */
791 if (randombuffer[0] == '5')
792 new_domain_record.random_result = ccache_reject;
795 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
796 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
799 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
800 from_address) >= 0 &&
801 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
804 else done = FALSE; /* Some timeout/connection problem */
807 /* If the host is accepting all local parts, as determined by the "random"
808 check, we don't need to waste time doing any further checking. */
810 if (new_domain_record.random_result != ccache_accept && done)
812 /* Get the rcpt_include_affixes flag from the transport if there is one,
813 but assume FALSE if there is not. */
816 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
817 transport_rcpt_address(addr,
818 (addr->transport == NULL)? FALSE :
819 addr->transport->rcpt_include_affixes)) >= 0 &&
820 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
824 new_address_record.result = ccache_accept;
825 else if (errno == 0 && responsebuffer[0] == '5')
827 *failure_ptr = US"recipient";
828 new_address_record.result = ccache_reject;
831 /* Do postmaster check if requested; if a full check is required, we
832 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
834 if (done && pm_mailfrom != NULL)
836 /*XXX not suitable for cutthrough - sequencing problems */
837 cutthrough_delivery= FALSE;
838 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
841 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
842 smtp_read_response(&inblock, responsebuffer,
843 sizeof(responsebuffer), '2', callout) &&
845 smtp_write_command(&outblock, FALSE,
846 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
847 smtp_read_response(&inblock, responsebuffer,
848 sizeof(responsebuffer), '2', callout) &&
850 /* First try using the current domain */
853 smtp_write_command(&outblock, FALSE,
854 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
855 smtp_read_response(&inblock, responsebuffer,
856 sizeof(responsebuffer), '2', callout)
861 /* If that doesn't work, and a full check is requested,
862 try without the domain. */
865 (options & vopt_callout_fullpm) != 0 &&
866 smtp_write_command(&outblock, FALSE,
867 "RCPT TO:<postmaster>\r\n") >= 0 &&
868 smtp_read_response(&inblock, responsebuffer,
869 sizeof(responsebuffer), '2', callout)
872 /* Sort out the cache record */
874 new_domain_record.postmaster_stamp = time(NULL);
877 new_domain_record.postmaster_result = ccache_accept;
878 else if (errno == 0 && responsebuffer[0] == '5')
880 *failure_ptr = US"postmaster";
881 setflag(addr, af_verify_pmfail);
882 new_domain_record.postmaster_result = ccache_reject;
885 } /* Random not accepted */
886 } /* MAIL FROM: accepted */
888 /* For any failure of the main check, other than a negative response, we just
889 close the connection and carry on. We can identify a negative response by the
890 fact that errno is zero. For I/O errors it will be non-zero
892 Set up different error texts for logging and for sending back to the caller
893 as an SMTP response. Log in all cases, using a one-line format. For sender
894 callouts, give a full response to the caller, but for recipient callouts,
895 don't give the IP address because this may be an internal host whose identity
896 is not to be widely broadcast. */
900 if (errno == ETIMEDOUT)
902 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
907 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
910 string_sprintf("response to \"%s\" from %s [%s] was: %s",
911 big_buffer, host->name, host->address,
912 string_printing(responsebuffer));
914 addr->user_message = is_recipient?
915 string_sprintf("Callout verification failed:\n%s", responsebuffer)
917 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
918 host->address, big_buffer, responsebuffer);
920 /* Hard rejection ends the process */
922 if (responsebuffer[0] == '5') /* Address rejected */
930 /* End the SMTP conversation and close the connection. */
932 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
933 and we have no cutthrough conn so far
934 here is where we want to leave the conn open */
935 if ( cutthrough_delivery
938 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
939 && !random_local_part
944 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
945 cutthrough_addr = *addr; /* Save the address_item for later logging */
946 cutthrough_addr.host_used = store_get(sizeof(host_item));
947 cutthrough_addr.host_used->name = host->name;
948 cutthrough_addr.host_used->address = host->address;
949 cutthrough_addr.host_used->port = port;
951 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
952 ctblock.buffer = ctbuffer;
953 ctblock.buffersize = sizeof(ctbuffer);
954 ctblock.ptr = ctbuffer;
955 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
956 ctblock.sock = cutthrough_fd;
960 /* Ensure no cutthrough on multiple address verifies */
961 if (options & vopt_callout_recipsender)
962 cancel_cutthrough_connection("multiple verify calls");
963 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
966 tls_close(FALSE, TRUE);
968 (void)close(inblock.sock);
971 } /* Loop through all hosts, while !done */
974 /* If we get here with done == TRUE, a successful callout happened, and yield
975 will be set OK or FAIL according to the response to the RCPT command.
976 Otherwise, we looped through the hosts but couldn't complete the business.
977 However, there may be domain-specific information to cache in both cases.
979 The value of the result field in the new_domain record is ccache_unknown if
980 there was an error before or with MAIL FROM:, and errno was not zero,
981 implying some kind of I/O error. We don't want to write the cache in that case.
982 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
984 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
986 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
989 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
993 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
994 (int)sizeof(dbdata_callout_cache));
995 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
996 " result=%d postmaster=%d random=%d\n",
997 new_domain_record.result,
998 new_domain_record.postmaster_result,
999 new_domain_record.random_result);
1003 /* If a definite result was obtained for the callout, cache it unless caching
1008 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1010 if (dbm_file == NULL)
1011 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1012 if (dbm_file == NULL)
1014 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1018 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1019 (int)sizeof(dbdata_callout_cache_address));
1020 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1021 (new_address_record.result == ccache_accept)? "positive" : "negative");
1026 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1027 temporary error. If there was only one host, and a response was received, leave
1028 it alone if supplying details. Otherwise, give a generic response. */
1032 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1033 is_recipient? "recipient" : "sender");
1036 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1038 addr->user_message = (!smtp_return_error_details)? dullmsg :
1039 string_sprintf("%s for <%s>.\n"
1040 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1041 "they may be permanently unreachable from this server. In the latter case,\n%s",
1042 dullmsg, addr->address,
1044 "the address will never be accepted."
1046 "you need to change the address or create an MX record for its domain\n"
1047 "if it is supposed to be generally accessible from the Internet.\n"
1048 "Talk to your mail administrator for details.");
1050 /* Force a specific error code */
1052 addr->basic_errno = ERRNO_CALLOUTDEFER;
1055 /* Come here from within the cache-reading code on fast-track exit. */
1058 if (dbm_file != NULL) dbfn_close(dbm_file);
1064 /* Called after recipient-acl to get a cutthrough connection open when
1065 one was requested and a recipient-verify wasn't subsequently done.
1068 open_cutthrough_connection( address_item * addr )
1072 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1073 /* We must use a copy of the address for verification, because it might
1077 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1078 (void) verify_address(&addr2, NULL,
1079 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1080 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1082 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1088 /* Send given number of bytes from the buffer */
1090 cutthrough_send(int n)
1092 if(cutthrough_fd < 0)
1097 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1099 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1102 transport_count += n;
1103 ctblock.ptr= ctblock.buffer;
1107 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1114 _cutthrough_puts(uschar * cp, int n)
1118 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1119 if(!cutthrough_send(ctblock.buffersize))
1122 *ctblock.ptr++ = *cp++;
1127 /* Buffered output of counted data block. Return boolean success */
1129 cutthrough_puts(uschar * cp, int n)
1131 if (cutthrough_fd < 0) return TRUE;
1132 if (_cutthrough_puts(cp, n)) return TRUE;
1133 cancel_cutthrough_connection("transmit failed");
1139 _cutthrough_flush_send( void )
1141 int n= ctblock.ptr-ctblock.buffer;
1144 if(!cutthrough_send(n))
1150 /* Send out any bufferred output. Return boolean success. */
1152 cutthrough_flush_send( void )
1154 if (_cutthrough_flush_send()) return TRUE;
1155 cancel_cutthrough_connection("transmit failed");
1161 cutthrough_put_nl( void )
1163 return cutthrough_puts(US"\r\n", 2);
1167 /* Get and check response from cutthrough target */
1169 cutthrough_response(char expect, uschar ** copy)
1171 smtp_inblock inblock;
1172 uschar inbuffer[4096];
1173 uschar responsebuffer[4096];
1175 inblock.buffer = inbuffer;
1176 inblock.buffersize = sizeof(inbuffer);
1177 inblock.ptr = inbuffer;
1178 inblock.ptrend = inbuffer;
1179 inblock.sock = cutthrough_fd;
1180 /* this relies on (inblock.sock == tls_out.active) */
1181 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1182 cancel_cutthrough_connection("target timeout on read");
1187 *copy= cp= string_copy(responsebuffer);
1188 /* Trim the trailing end of line */
1189 cp += Ustrlen(responsebuffer);
1190 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1191 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1194 return responsebuffer[0];
1198 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1200 cutthrough_predata( void )
1202 if(cutthrough_fd < 0)
1205 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1206 cutthrough_puts(US"DATA\r\n", 6);
1207 cutthrough_flush_send();
1209 /* Assume nothing buffered. If it was it gets ignored. */
1210 return cutthrough_response('3', NULL) == '3';
1214 /* Buffered send of headers. Return success boolean. */
1215 /* Expands newlines to wire format (CR,NL). */
1216 /* Also sends header-terminating blank line. */
1218 cutthrough_headers_send( void )
1221 uschar * cp1, * cp2;
1223 if(cutthrough_fd < 0)
1226 for(h= header_list; h != NULL; h= h->next)
1227 if(h->type != htype_old && h->text != NULL)
1228 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1229 if( !cutthrough_puts(cp1, cp2-cp1)
1230 || !cutthrough_put_nl())
1233 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1234 return cutthrough_put_nl();
1239 close_cutthrough_connection( const char * why )
1241 if(cutthrough_fd >= 0)
1243 /* We could be sending this after a bunch of data, but that is ok as
1244 the only way to cancel the transfer in dataphase is to drop the tcp
1245 conn before the final dot.
1247 ctblock.ptr = ctbuffer;
1248 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1249 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1250 _cutthrough_flush_send();
1251 /* No wait for response */
1254 tls_close(FALSE, TRUE);
1256 (void)close(cutthrough_fd);
1258 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1260 ctblock.ptr = ctbuffer;
1264 cancel_cutthrough_connection( const char * why )
1266 close_cutthrough_connection(why);
1267 cutthrough_delivery= FALSE;
1273 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1274 Log an OK response as a transmission.
1275 Close the connection.
1276 Return smtp response-class digit.
1279 cutthrough_finaldot( void )
1281 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1283 /* Assume data finshed with new-line */
1284 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1285 return cutthrough_addr.message;
1287 switch(cutthrough_response('2', &cutthrough_addr.message))
1290 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1291 close_cutthrough_connection("delivered");
1295 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1299 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1305 return cutthrough_addr.message;
1310 /*************************************************
1311 * Copy error to toplevel address *
1312 *************************************************/
1314 /* This function is used when a verify fails or defers, to ensure that the
1315 failure or defer information is in the original toplevel address. This applies
1316 when an address is redirected to a single new address, and the failure or
1317 deferral happens to the child address.
1320 vaddr the verify address item
1321 addr the final address item
1324 Returns: the value of YIELD
1328 copy_error(address_item *vaddr, address_item *addr, int yield)
1332 vaddr->message = addr->message;
1333 vaddr->user_message = addr->user_message;
1334 vaddr->basic_errno = addr->basic_errno;
1335 vaddr->more_errno = addr->more_errno;
1336 vaddr->p.address_data = addr->p.address_data;
1337 copyflag(vaddr, addr, af_pass_message);
1345 /**************************************************
1346 * printf that automatically handles TLS if needed *
1347 ***************************************************/
1349 /* This function is used by verify_address() as a substitute for all fprintf()
1350 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1351 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1352 that assumes that we always use the smtp_out FILE* when not using TLS or the
1353 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1354 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1358 f the candidate FILE* to write to
1359 format format string
1360 ... optional arguments
1366 static void PRINTF_FUNCTION(2,3)
1367 respond_printf(FILE *f, const char *format, ...)
1371 va_start(ap, format);
1372 if (smtp_out && (f == smtp_out))
1373 smtp_vprintf(format, ap);
1375 vfprintf(f, format, ap);
1381 /*************************************************
1382 * Verify an email address *
1383 *************************************************/
1385 /* This function is used both for verification (-bv and at other times) and
1386 address testing (-bt), which is indicated by address_test_mode being set.
1389 vaddr contains the address to verify; the next field in this block
1391 f if not NULL, write the result to this file
1392 options various option bits:
1393 vopt_fake_sender => this sender verify is not for the real
1394 sender (it was verify=sender=xxxx or an address from a
1395 header line) - rewriting must not change sender_address
1396 vopt_is_recipient => this is a recipient address, otherwise
1397 it's a sender address - this affects qualification and
1398 rewriting and messages from callouts
1399 vopt_qualify => qualify an unqualified address; else error
1400 vopt_expn => called from SMTP EXPN command
1401 vopt_success_on_redirect => when a new address is generated
1402 the verification instantly succeeds
1404 These ones are used by do_callout() -- the options variable
1407 vopt_callout_fullpm => if postmaster check, do full one
1408 vopt_callout_no_cache => don't use callout cache
1409 vopt_callout_random => do the "random" thing
1410 vopt_callout_recipsender => use real sender for recipient
1411 vopt_callout_recippmaster => use postmaster for recipient
1413 callout if > 0, specifies that callout is required, and gives timeout
1414 for individual commands
1415 callout_overall if > 0, gives overall timeout for the callout function;
1416 if < 0, a default is used (see do_callout())
1417 callout_connect the connection timeout for callouts
1418 se_mailfrom when callout is requested to verify a sender, use this
1419 in MAIL FROM; NULL => ""
1420 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1421 thing and use this as the sender address (may be "")
1423 routed if not NULL, set TRUE if routing succeeded, so we can
1424 distinguish between routing failed and callout failed
1426 Returns: OK address verified
1427 FAIL address failed to verify
1428 DEFER can't tell at present
1432 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1433 int callout_overall, int callout_connect, uschar *se_mailfrom,
1434 uschar *pm_mailfrom, BOOL *routed)
1437 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1438 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1439 BOOL expn = (options & vopt_expn) != 0;
1440 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1443 int verify_type = expn? v_expn :
1444 address_test_mode? v_none :
1445 is_recipient? v_recipient : v_sender;
1446 address_item *addr_list;
1447 address_item *addr_new = NULL;
1448 address_item *addr_remote = NULL;
1449 address_item *addr_local = NULL;
1450 address_item *addr_succeed = NULL;
1451 uschar **failure_ptr = is_recipient?
1452 &recipient_verify_failure : &sender_verify_failure;
1453 uschar *ko_prefix, *cr;
1454 uschar *address = vaddr->address;
1455 uschar *save_sender;
1456 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1458 /* Clear, just in case */
1460 *failure_ptr = NULL;
1462 /* Set up a prefix and suffix for error message which allow us to use the same
1463 output statements both in EXPN mode (where an SMTP response is needed) and when
1464 debugging with an output file. */
1468 ko_prefix = US"553 ";
1471 else ko_prefix = cr = US"";
1473 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1475 if (parse_find_at(address) == NULL)
1477 if ((options & vopt_qualify) == 0)
1480 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1481 ko_prefix, address, cr);
1482 *failure_ptr = US"qualify";
1485 address = rewrite_address_qualify(address, is_recipient);
1490 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1491 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1494 /* Rewrite and report on it. Clear the domain and local part caches - these
1495 may have been set by domains and local part tests during an ACL. */
1497 if (global_rewrite_rules != NULL)
1499 uschar *old = address;
1500 address = rewrite_address(address, is_recipient, FALSE,
1501 global_rewrite_rules, rewrite_existflags);
1504 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1505 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1506 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1510 /* If this is the real sender address, we must update sender_address at
1511 this point, because it may be referred to in the routers. */
1513 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1514 sender_address = address;
1516 /* If the address was rewritten to <> no verification can be done, and we have
1517 to return OK. This rewriting is permitted only for sender addresses; for other
1518 addresses, such rewriting fails. */
1520 if (address[0] == 0) return OK;
1522 /* Save a copy of the sender address for re-instating if we change it to <>
1523 while verifying a sender address (a nice bit of self-reference there). */
1525 save_sender = sender_address;
1527 /* Update the address structure with the possibly qualified and rewritten
1528 address. Set it up as the starting address on the chain of new addresses. */
1530 vaddr->address = address;
1533 /* We need a loop, because an address can generate new addresses. We must also
1534 cope with generated pipes and files at the top level. (See also the code and
1535 comment in deliver.c.) However, it is usually the case that the router for
1536 user's .forward files has its verify flag turned off.
1538 If an address generates more than one child, the loop is used only when
1539 full_info is set, and this can only be set locally. Remote enquiries just get
1540 information about the top level address, not anything that it generated. */
1542 while (addr_new != NULL)
1545 address_item *addr = addr_new;
1547 addr_new = addr->next;
1552 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1553 debug_printf("Considering %s\n", addr->address);
1556 /* Handle generated pipe, file or reply addresses. We don't get these
1557 when handling EXPN, as it does only one level of expansion. */
1559 if (testflag(addr, af_pfr))
1566 if (addr->address[0] == '>')
1568 allow = testflag(addr, af_allow_reply);
1569 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1573 allow = (addr->address[0] == '|')?
1574 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1575 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1578 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1579 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1580 "%s\n", addr->message);
1582 fprintf(f, "\n transport = %s\n", addr->transport->name);
1584 fprintf(f, " *** forbidden ***\n");
1589 /* Just in case some router parameter refers to it. */
1591 return_path = (addr->p.errors_address != NULL)?
1592 addr->p.errors_address : sender_address;
1594 /* Split the address into domain and local part, handling the %-hack if
1595 necessary, and then route it. While routing a sender address, set
1596 $sender_address to <> because that is what it will be if we were trying to
1597 send a bounce to the sender. */
1599 if (routed != NULL) *routed = FALSE;
1600 if ((rc = deliver_split_address(addr)) == OK)
1602 if (!is_recipient) sender_address = null_sender;
1603 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1604 &addr_succeed, verify_type);
1605 sender_address = save_sender; /* Put back the real sender */
1608 /* If routing an address succeeded, set the flag that remembers, for use when
1609 an ACL cached a sender verify (in case a callout fails). Then if routing set
1610 up a list of hosts or the transport has a host list, and the callout option
1611 is set, and we aren't in a host checking run, do the callout verification,
1612 and set another flag that notes that a callout happened. */
1616 if (routed != NULL) *routed = TRUE;
1619 host_item *host_list = addr->host_list;
1621 /* Make up some data for use in the case where there is no remote
1624 transport_feedback tf = {
1625 NULL, /* interface (=> any) */
1626 US"smtp", /* port */
1627 US"smtp", /* protocol */
1629 US"$smtp_active_hostname", /* helo_data */
1630 FALSE, /* hosts_override */
1631 FALSE, /* hosts_randomize */
1632 FALSE, /* gethostbyname */
1633 TRUE, /* qualify_single */
1634 FALSE /* search_parents */
1637 /* If verification yielded a remote transport, we want to use that
1638 transport's options, so as to mimic what would happen if we were really
1639 sending a message to this address. */
1641 if (addr->transport != NULL && !addr->transport->info->local)
1643 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1645 /* If the transport has hosts and the router does not, or if the
1646 transport is configured to override the router's hosts, we must build a
1647 host list of the transport's hosts, and find the IP addresses */
1649 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1652 uschar *save_deliver_domain = deliver_domain;
1653 uschar *save_deliver_localpart = deliver_localpart;
1655 host_list = NULL; /* Ignore the router's hosts */
1657 deliver_domain = addr->domain;
1658 deliver_localpart = addr->local_part;
1659 s = expand_string(tf.hosts);
1660 deliver_domain = save_deliver_domain;
1661 deliver_localpart = save_deliver_localpart;
1665 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1666 "\"%s\" in %s transport for callout: %s", tf.hosts,
1667 addr->transport->name, expand_string_message);
1672 uschar *canonical_name;
1673 host_item *host, *nexthost;
1674 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1676 /* Just ignore failures to find a host address. If we don't manage
1677 to find any addresses, the callout will defer. Note that more than
1678 one address may be found for a single host, which will result in
1679 additional host items being inserted into the chain. Hence we must
1680 save the next host first. */
1682 flags = HOST_FIND_BY_A;
1683 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1684 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1686 for (host = host_list; host != NULL; host = nexthost)
1688 nexthost = host->next;
1689 if (tf.gethostbyname ||
1690 string_is_ip_address(host->name, NULL) != 0)
1691 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1693 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1694 &canonical_name, NULL);
1700 /* Can only do a callout if we have at least one host! If the callout
1701 fails, it will have set ${sender,recipient}_verify_failure. */
1703 if (host_list != NULL)
1705 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1706 if (host_checking && !host_checking_callout)
1709 debug_printf("... callout omitted by default when host testing\n"
1710 "(Use -bhc if you want the callouts to happen.)\n");
1715 deliver_set_expansions(addr);
1717 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1718 callout_connect, options, se_mailfrom, pm_mailfrom);
1723 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1724 "transport provided a host list\n");
1729 /* Otherwise, any failure is a routing failure */
1731 else *failure_ptr = US"route";
1733 /* A router may return REROUTED if it has set up a child address as a result
1734 of a change of domain name (typically from widening). In this case we always
1735 want to continue to verify the new child. */
1737 if (rc == REROUTED) continue;
1739 /* Handle hard failures */
1746 address_item *p = addr->parent;
1748 respond_printf(f, "%s%s %s", ko_prefix,
1749 full_info? addr->address : address,
1750 address_test_mode? "is undeliverable" : "failed to verify");
1751 if (!expn && admin_user)
1753 if (addr->basic_errno > 0)
1754 respond_printf(f, ": %s", strerror(addr->basic_errno));
1755 if (addr->message != NULL)
1756 respond_printf(f, ": %s", addr->message);
1759 /* Show parents iff doing full info */
1761 if (full_info) while (p != NULL)
1763 respond_printf(f, "%s\n <-- %s", cr, p->address);
1766 respond_printf(f, "%s\n", cr);
1768 cancel_cutthrough_connection("routing hard fail");
1770 if (!full_info) return copy_error(vaddr, addr, FAIL);
1776 else if (rc == DEFER)
1781 address_item *p = addr->parent;
1782 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1783 full_info? addr->address : address);
1784 if (!expn && admin_user)
1786 if (addr->basic_errno > 0)
1787 respond_printf(f, ": %s", strerror(addr->basic_errno));
1788 if (addr->message != NULL)
1789 respond_printf(f, ": %s", addr->message);
1790 else if (addr->basic_errno <= 0)
1791 respond_printf(f, ": unknown error");
1794 /* Show parents iff doing full info */
1796 if (full_info) while (p != NULL)
1798 respond_printf(f, "%s\n <-- %s", cr, p->address);
1801 respond_printf(f, "%s\n", cr);
1803 cancel_cutthrough_connection("routing soft fail");
1805 if (!full_info) return copy_error(vaddr, addr, DEFER);
1806 else if (yield == OK) yield = DEFER;
1809 /* If we are handling EXPN, we do not want to continue to route beyond
1810 the top level (whose address is in "address"). */
1814 uschar *ok_prefix = US"250-";
1815 if (addr_new == NULL)
1817 if (addr_local == NULL && addr_remote == NULL)
1818 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1820 respond_printf(f, "250 <%s>\r\n", address);
1822 else while (addr_new != NULL)
1824 address_item *addr2 = addr_new;
1825 addr_new = addr2->next;
1826 if (addr_new == NULL) ok_prefix = US"250 ";
1827 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1832 /* Successful routing other than EXPN. */
1836 /* Handle successful routing when short info wanted. Otherwise continue for
1837 other (generated) addresses. Short info is the operational case. Full info
1838 can be requested only when debug_selector != 0 and a file is supplied.
1840 There is a conflict between the use of aliasing as an alternate email
1841 address, and as a sort of mailing list. If an alias turns the incoming
1842 address into just one address (e.g. J.Caesar->jc44) you may well want to
1843 carry on verifying the generated address to ensure it is valid when
1844 checking incoming mail. If aliasing generates multiple addresses, you
1845 probably don't want to do this. Exim therefore treats the generation of
1846 just a single new address as a special case, and continues on to verify the
1847 generated address. */
1849 if (!full_info && /* Stop if short info wanted AND */
1850 (((addr_new == NULL || /* No new address OR */
1851 addr_new->next != NULL || /* More than one new address OR */
1852 testflag(addr_new, af_pfr))) /* New address is pfr */
1854 (addr_new != NULL && /* At least one new address AND */
1855 success_on_redirect))) /* success_on_redirect is set */
1857 if (f != NULL) fprintf(f, "%s %s\n", address,
1858 address_test_mode? "is deliverable" : "verified");
1860 /* If we have carried on to verify a child address, we want the value
1861 of $address_data to be that of the child */
1863 vaddr->p.address_data = addr->p.address_data;
1867 } /* Loop for generated addresses */
1869 /* Display the full results of the successful routing, including any generated
1870 addresses. Control gets here only when full_info is set, which requires f not
1871 to be NULL, and this occurs only when a top-level verify is called with the
1872 debugging switch on.
1874 If there are no local and no remote addresses, and there were no pipes, files,
1875 or autoreplies, and there were no errors or deferments, the message is to be
1876 discarded, usually because of the use of :blackhole: in an alias file. */
1878 if (allok && addr_local == NULL && addr_remote == NULL)
1880 fprintf(f, "mail to %s is discarded\n", address);
1884 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1886 while (addr_list != NULL)
1888 address_item *addr = addr_list;
1889 address_item *p = addr->parent;
1890 addr_list = addr->next;
1892 fprintf(f, "%s", CS addr->address);
1893 #ifdef EXPERIMENTAL_SRS
1894 if(addr->p.srs_sender)
1895 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1898 /* If the address is a duplicate, show something about it. */
1900 if (!testflag(addr, af_pfr))
1903 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1904 fprintf(f, " [duplicate, would not be delivered]");
1905 else tree_add_duplicate(addr->unique, addr);
1908 /* Now show its parents */
1912 fprintf(f, "\n <-- %s", p->address);
1917 /* Show router, and transport */
1919 fprintf(f, "router = %s, ", addr->router->name);
1920 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1921 addr->transport->name);
1923 /* Show any hosts that are set up by a router unless the transport
1924 is going to override them; fiddle a bit to get a nice format. */
1926 if (addr->host_list != NULL && addr->transport != NULL &&
1927 !addr->transport->overrides_hosts)
1932 for (h = addr->host_list; h != NULL; h = h->next)
1934 int len = Ustrlen(h->name);
1935 if (len > maxlen) maxlen = len;
1936 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1937 if (len > maxaddlen) maxaddlen = len;
1939 for (h = addr->host_list; h != NULL; h = h->next)
1941 int len = Ustrlen(h->name);
1942 fprintf(f, " host %s ", h->name);
1943 while (len++ < maxlen) fprintf(f, " ");
1944 if (h->address != NULL)
1946 fprintf(f, "[%s] ", h->address);
1947 len = Ustrlen(h->address);
1949 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1951 fprintf(f, "[unknown] ");
1955 while (len++ < maxaddlen) fprintf(f," ");
1956 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1957 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1958 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1965 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1966 the -bv or -bt case). */
1974 /*************************************************
1975 * Check headers for syntax errors *
1976 *************************************************/
1978 /* This function checks those header lines that contain addresses, and verifies
1979 that all the addresses therein are syntactially correct.
1982 msgptr where to put an error message
1989 verify_check_headers(uschar **msgptr)
1995 for (h = header_list; h != NULL && yield == OK; h = h->next)
1997 if (h->type != htype_from &&
1998 h->type != htype_reply_to &&
1999 h->type != htype_sender &&
2000 h->type != htype_to &&
2001 h->type != htype_cc &&
2002 h->type != htype_bcc)
2005 colon = Ustrchr(h->text, ':');
2007 while (isspace(*s)) s++;
2009 /* Loop for multiple addresses in the header, enabling group syntax. Note
2010 that we have to reset this after the header has been scanned. */
2012 parse_allow_group = TRUE;
2016 uschar *ss = parse_find_address_end(s, FALSE);
2017 uschar *recipient, *errmess;
2018 int terminator = *ss;
2019 int start, end, domain;
2021 /* Temporarily terminate the string at this point, and extract the
2022 operative address within, allowing group syntax. */
2025 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2028 /* Permit an unqualified address only if the message is local, or if the
2029 sending host is configured to be permitted to send them. */
2031 if (recipient != NULL && domain == 0)
2033 if (h->type == htype_from || h->type == htype_sender)
2035 if (!allow_unqualified_sender) recipient = NULL;
2039 if (!allow_unqualified_recipient) recipient = NULL;
2041 if (recipient == NULL) errmess = US"unqualified address not permitted";
2044 /* It's an error if no address could be extracted, except for the special
2045 case of an empty address. */
2047 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2049 uschar *verb = US"is";
2054 /* Arrange not to include any white space at the end in the
2055 error message or the header name. */
2057 while (t > s && isspace(t[-1])) t--;
2058 while (tt > h->text && isspace(tt[-1])) tt--;
2060 /* Add the address that failed to the error message, since in a
2061 header with very many addresses it is sometimes hard to spot
2062 which one is at fault. However, limit the amount of address to
2063 quote - cases have been seen where, for example, a missing double
2064 quote in a humungous To: header creates an "address" that is longer
2065 than string_sprintf can handle. */
2074 *msgptr = string_printing(
2075 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2076 errmess, tt - h->text, h->text, verb, len, s));
2079 break; /* Out of address loop */
2082 /* Advance to the next address */
2084 s = ss + (terminator? 1:0);
2085 while (isspace(*s)) s++;
2086 } /* Next address */
2088 parse_allow_group = FALSE;
2089 parse_found_group = FALSE;
2090 } /* Next header unless yield has been set FALSE */
2097 /*************************************************
2098 * Check for blind recipients *
2099 *************************************************/
2101 /* This function checks that every (envelope) recipient is mentioned in either
2102 the To: or Cc: header lines, thus detecting blind carbon copies.
2104 There are two ways of scanning that could be used: either scan the header lines
2105 and tick off the recipients, or scan the recipients and check the header lines.
2106 The original proposed patch did the former, but I have chosen to do the latter,
2107 because (a) it requires no memory and (b) will use fewer resources when there
2108 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2111 Returns: OK if there are no blind recipients
2112 FAIL if there is at least one blind recipient
2116 verify_check_notblind(void)
2119 for (i = 0; i < recipients_count; i++)
2123 uschar *address = recipients_list[i].address;
2125 for (h = header_list; !found && h != NULL; h = h->next)
2129 if (h->type != htype_to && h->type != htype_cc) continue;
2131 colon = Ustrchr(h->text, ':');
2133 while (isspace(*s)) s++;
2135 /* Loop for multiple addresses in the header, enabling group syntax. Note
2136 that we have to reset this after the header has been scanned. */
2138 parse_allow_group = TRUE;
2142 uschar *ss = parse_find_address_end(s, FALSE);
2143 uschar *recipient,*errmess;
2144 int terminator = *ss;
2145 int start, end, domain;
2147 /* Temporarily terminate the string at this point, and extract the
2148 operative address within, allowing group syntax. */
2151 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2154 /* If we found a valid recipient that has a domain, compare it with the
2155 envelope recipient. Local parts are compared case-sensitively, domains
2156 case-insensitively. By comparing from the start with length "domain", we
2157 include the "@" at the end, which ensures that we are comparing the whole
2158 local part of each address. */
2160 if (recipient != NULL && domain != 0)
2162 found = Ustrncmp(recipient, address, domain) == 0 &&
2163 strcmpic(recipient + domain, address + domain) == 0;
2167 /* Advance to the next address */
2169 s = ss + (terminator? 1:0);
2170 while (isspace(*s)) s++;
2171 } /* Next address */
2173 parse_allow_group = FALSE;
2174 parse_found_group = FALSE;
2175 } /* Next header (if found is false) */
2177 if (!found) return FAIL;
2178 } /* Next recipient */
2185 /*************************************************
2186 * Find if verified sender *
2187 *************************************************/
2189 /* Usually, just a single address is verified as the sender of the message.
2190 However, Exim can be made to verify other addresses as well (often related in
2191 some way), and this is useful in some environments. There may therefore be a
2192 chain of such addresses that have previously been tested. This function finds
2193 whether a given address is on the chain.
2195 Arguments: the address to be verified
2196 Returns: pointer to an address item, or NULL
2200 verify_checked_sender(uschar *sender)
2203 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2204 if (Ustrcmp(sender, addr->address) == 0) break;
2212 /*************************************************
2213 * Get valid header address *
2214 *************************************************/
2216 /* Scan the originator headers of the message, looking for an address that
2217 verifies successfully. RFC 822 says:
2219 o The "Sender" field mailbox should be sent notices of
2220 any problems in transport or delivery of the original
2221 messages. If there is no "Sender" field, then the
2222 "From" field mailbox should be used.
2224 o If the "Reply-To" field exists, then the reply should
2225 go to the addresses indicated in that field and not to
2226 the address(es) indicated in the "From" field.
2228 So we check a Sender field if there is one, else a Reply_to field, else a From
2229 field. As some strange messages may have more than one of these fields,
2230 especially if they are resent- fields, check all of them if there is more than
2234 user_msgptr points to where to put a user error message
2235 log_msgptr points to where to put a log error message
2236 callout timeout for callout check (passed to verify_address())
2237 callout_overall overall callout timeout (ditto)
2238 callout_connect connect callout timeout (ditto)
2239 se_mailfrom mailfrom for verify; NULL => ""
2240 pm_mailfrom sender for pm callout check (passed to verify_address())
2241 options callout options (passed to verify_address())
2242 verrno where to put the address basic_errno
2244 If log_msgptr is set to something without setting user_msgptr, the caller
2245 normally uses log_msgptr for both things.
2247 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2248 FAIL is given if no appropriate headers are found
2252 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2253 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2254 uschar *pm_mailfrom, int options, int *verrno)
2256 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2261 for (i = 0; i < 3 && !done; i++)
2264 for (h = header_list; h != NULL && !done; h = h->next)
2266 int terminator, new_ok;
2267 uschar *s, *ss, *endname;
2269 if (h->type != header_types[i]) continue;
2270 s = endname = Ustrchr(h->text, ':') + 1;
2272 /* Scan the addresses in the header, enabling group syntax. Note that we
2273 have to reset this after the header has been scanned. */
2275 parse_allow_group = TRUE;
2279 address_item *vaddr;
2281 while (isspace(*s) || *s == ',') s++;
2282 if (*s == 0) break; /* End of header */
2284 ss = parse_find_address_end(s, FALSE);
2286 /* The terminator is a comma or end of header, but there may be white
2287 space preceding it (including newline for the last address). Move back
2288 past any white space so we can check against any cached envelope sender
2289 address verifications. */
2291 while (isspace(ss[-1])) ss--;
2295 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2296 (int)(endname - h->text), h->text, s);
2298 /* See if we have already verified this address as an envelope sender,
2299 and if so, use the previous answer. */
2301 vaddr = verify_checked_sender(s);
2303 if (vaddr != NULL && /* Previously checked */
2304 (callout <= 0 || /* No callout needed; OR */
2305 vaddr->special_action > 256)) /* Callout was done */
2307 new_ok = vaddr->special_action & 255;
2308 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2309 *ss = terminator; /* Restore shortened string */
2312 /* Otherwise we run the verification now. We must restore the shortened
2313 string before running the verification, so the headers are correct, in
2314 case there is any rewriting. */
2318 int start, end, domain;
2319 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2324 /* If we found an empty address, just carry on with the next one, but
2325 kill the message. */
2327 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2334 /* If verification failed because of a syntax error, fail this
2335 function, and ensure that the failing address gets added to the error
2338 if (address == NULL)
2341 while (ss > s && isspace(ss[-1])) ss--;
2342 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2343 "scanning for sender: %s in \"%.*s\"",
2344 endname - h->text, h->text, *log_msgptr, ss - s, s);
2350 /* Else go ahead with the sender verification. But it isn't *the*
2351 sender of the message, so set vopt_fake_sender to stop sender_address
2352 being replaced after rewriting or qualification. */
2356 vaddr = deliver_make_addr(address, FALSE);
2357 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2358 callout, callout_overall, callout_connect, se_mailfrom,
2363 /* We now have the result, either newly found, or cached. If we are
2364 giving out error details, set a specific user error. This means that the
2365 last of these will be returned to the user if all three fail. We do not
2366 set a log message - the generic one below will be used. */
2370 *verrno = vaddr->basic_errno;
2371 if (smtp_return_error_details)
2373 *user_msgptr = string_sprintf("Rejected after DATA: "
2374 "could not verify \"%.*s\" header address\n%s: %s",
2375 endname - h->text, h->text, vaddr->address, vaddr->message);
2379 /* Success or defer */
2388 if (new_ok == DEFER) yield = DEFER;
2390 /* Move on to any more addresses in the header */
2393 } /* Next address */
2395 parse_allow_group = FALSE;
2396 parse_found_group = FALSE;
2397 } /* Next header, unless done */
2398 } /* Next header type unless done */
2400 if (yield == FAIL && *log_msgptr == NULL)
2401 *log_msgptr = US"there is no valid sender in any header line";
2403 if (yield == DEFER && *log_msgptr == NULL)
2404 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2412 /*************************************************
2413 * Get RFC 1413 identification *
2414 *************************************************/
2416 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2417 the timeout is set to zero, then the query is not done. There may also be lists
2418 of hosts and nets which are exempt. To guard against malefactors sending
2419 non-printing characters which could, for example, disrupt a message's headers,
2420 make sure the string consists of printing characters only.
2423 port the port to connect to; usually this is IDENT_PORT (113), but when
2424 running in the test harness with -bh a different value is used.
2428 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2432 verify_get_ident(int port)
2434 int sock, host_af, qlen;
2435 int received_sender_port, received_interface_port, n;
2437 uschar buffer[2048];
2439 /* Default is no ident. Check whether we want to do an ident check for this
2442 sender_ident = NULL;
2443 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2446 DEBUG(D_ident) debug_printf("doing ident callback\n");
2448 /* Set up a connection to the ident port of the remote host. Bind the local end
2449 to the incoming interface address. If the sender host address is an IPv6
2450 address, the incoming interface address will also be IPv6. */
2452 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2453 sock = ip_socket(SOCK_STREAM, host_af);
2454 if (sock < 0) return;
2456 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2458 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2463 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2466 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2468 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2469 sender_host_address);
2473 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2474 sender_host_address, strerror(errno));
2479 /* Construct and send the query. */
2481 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2482 qlen = Ustrlen(buffer);
2483 if (send(sock, buffer, qlen, 0) < 0)
2485 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2489 /* Read a response line. We put it into the rest of the buffer, using several
2490 recv() calls if necessary. */
2498 int size = sizeof(buffer) - (p - buffer);
2500 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2501 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2502 if (count <= 0) goto END_OFF; /* Read error or EOF */
2504 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2505 generous, and accept a plain \n terminator as well. The only illegal
2508 for (pp = p; pp < p + count; pp++)
2510 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2513 if (pp[-1] == '\r') pp--;
2515 goto GOT_DATA; /* Break out of both loops */
2519 /* Reached the end of the data without finding \n. Let the loop continue to
2520 read some more, if there is room. */
2527 /* We have received a line of data. Check it carefully. It must start with the
2528 same two port numbers that we sent, followed by data as defined by the RFC. For
2531 12345 , 25 : USERID : UNIX :root
2533 However, the amount of white space may be different to what we sent. In the
2534 "osname" field there may be several sub-fields, comma separated. The data we
2535 actually want to save follows the third colon. Some systems put leading spaces
2536 in it - we discard those. */
2538 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2539 &received_interface_port, &n) != 2 ||
2540 received_sender_port != sender_host_port ||
2541 received_interface_port != interface_port)
2544 p = buffer + qlen + n;
2545 while(isspace(*p)) p++;
2546 if (*p++ != ':') goto END_OFF;
2547 while(isspace(*p)) p++;
2548 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2550 while(isspace(*p)) p++;
2551 if (*p++ != ':') goto END_OFF;
2552 while (*p != 0 && *p != ':') p++;
2553 if (*p++ == 0) goto END_OFF;
2554 while(isspace(*p)) p++;
2555 if (*p == 0) goto END_OFF;
2557 /* The rest of the line is the data we want. We turn it into printing
2558 characters when we save it, so that it cannot mess up the format of any logging
2559 or Received: lines into which it gets inserted. We keep a maximum of 127
2562 sender_ident = string_printing(string_copyn(p, 127));
2563 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2573 /*************************************************
2574 * Match host to a single host-list item *
2575 *************************************************/
2577 /* This function compares a host (name or address) against a single item
2578 from a host list. The host name gets looked up if it is needed and is not
2579 already known. The function is called from verify_check_this_host() via
2580 match_check_list(), which is why most of its arguments are in a single block.
2583 arg the argument block (see below)
2584 ss the host-list item
2585 valueptr where to pass back looked up data, or NULL
2586 error for error message when returning ERROR
2589 host_name (a) the host name, or
2590 (b) NULL, implying use sender_host_name and
2591 sender_host_aliases, looking them up if required, or
2592 (c) the empty string, meaning that only IP address matches
2594 host_address the host address
2595 host_ipv4 the IPv4 address taken from an IPv6 one
2599 DEFER lookup deferred
2600 ERROR (a) failed to find the host name or IP address, or
2601 (b) unknown lookup type specified, or
2602 (c) host name encountered when only IP addresses are
2607 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2609 check_host_block *cb = (check_host_block *)arg;
2612 BOOL iplookup = FALSE;
2613 BOOL isquery = FALSE;
2614 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2619 /* Optimize for the special case when the pattern is "*". */
2621 if (*ss == '*' && ss[1] == 0) return OK;
2623 /* If the pattern is empty, it matches only in the case when there is no host -
2624 this can occur in ACL checking for SMTP input using the -bs option. In this
2625 situation, the host address is the empty string. */
2627 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2628 if (*ss == 0) return FAIL;
2630 /* If the pattern is precisely "@" then match against the primary host name,
2631 provided that host name matching is permitted; if it's "@[]" match against the
2632 local host's IP addresses. */
2638 if (isiponly) return ERROR;
2639 ss = primary_hostname;
2641 else if (Ustrcmp(ss, "@[]") == 0)
2643 ip_address_item *ip;
2644 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2645 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2650 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2651 a (possibly masked) comparision with the current IP address. */
2653 if (string_is_ip_address(ss, &maskoffset) != 0)
2654 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2656 /* The pattern is not an IP address. A common error that people make is to omit
2657 one component of an IPv4 address, either by accident, or believing that, for
2658 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,
2659 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2660 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2661 ancient specification.) To aid in debugging these cases, we give a specific
2662 error if the pattern contains only digits and dots or contains a slash preceded
2663 only by digits and dots (a slash at the start indicates a file name and of
2664 course slashes may be present in lookups, but not preceded only by digits and
2667 for (t = ss; isdigit(*t) || *t == '.'; t++);
2668 if (*t == 0 || (*t == '/' && t != ss))
2670 *error = US"malformed IPv4 address or address mask";
2674 /* See if there is a semicolon in the pattern */
2676 semicolon = Ustrchr(ss, ';');
2678 /* If we are doing an IP address only match, then all lookups must be IP
2679 address lookups, even if there is no "net-". */
2683 iplookup = semicolon != NULL;
2686 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2687 a lookup on a masked IP network, in textual form. We obey this code even if we
2688 have already set iplookup, so as to skip over the "net-" prefix and to set the
2689 mask length. The net- stuff really only applies to single-key lookups where the
2690 key is implicit. For query-style lookups the key is specified in the query.
2691 From release 4.30, the use of net- for query style is no longer needed, but we
2692 retain it for backward compatibility. */
2694 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2697 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2698 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2699 iplookup = (*t++ == '-');
2703 /* Do the IP address lookup if that is indeed what we have */
2711 uschar *filename, *key, *result;
2714 /* Find the search type */
2716 search_type = search_findtype(t, semicolon - t);
2718 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2719 search_error_message);
2721 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2722 is no file name, and the "key" is just the query. For query-style with a file
2723 name, we have to fish the file off the start of the query. For a single-key
2724 lookup, the key is the current IP address, masked appropriately, and
2725 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2726 dot separators instead of colons, except when the lookup type is "iplsearch".
2729 if (mac_islookup(search_type, lookup_absfilequery))
2731 filename = semicolon + 1;
2733 while (*key != 0 && !isspace(*key)) key++;
2734 filename = string_copyn(filename, key - filename);
2735 while (isspace(*key)) key++;
2737 else if (mac_islookup(search_type, lookup_querystyle))
2740 key = semicolon + 1;
2742 else /* Single-key style */
2744 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2746 insize = host_aton(cb->host_address, incoming);
2747 host_mask(insize, incoming, mlen);
2748 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2750 filename = semicolon + 1;
2753 /* Now do the actual lookup; note that there is no search_close() because
2754 of the caching arrangements. */
2756 handle = search_open(filename, search_type, 0, NULL, NULL);
2757 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2758 search_error_message);
2759 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2760 if (valueptr != NULL) *valueptr = result;
2761 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2764 /* The pattern is not an IP address or network reference of any kind. That is,
2765 it is a host name pattern. If this is an IP only match, there's an error in the
2770 *error = US"cannot match host name in match_ip list";
2774 /* Check the characters of the pattern to see if they comprise only letters,
2775 digits, full stops, and hyphens (the constituents of domain names). Allow
2776 underscores, as they are all too commonly found. Sigh. Also, if
2777 allow_utf8_domains is set, allow top-bit characters. */
2779 for (t = ss; *t != 0; t++)
2780 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2781 (!allow_utf8_domains || *t < 128)) break;
2783 /* If the pattern is a complete domain name, with no fancy characters, look up
2784 its IP address and match against that. Note that a multi-homed host will add
2785 items to the chain. */
2796 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2797 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2800 for (hh = &h; hh != NULL; hh = hh->next)
2802 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2806 if (rc == HOST_FIND_AGAIN) return DEFER;
2807 *error = string_sprintf("failed to find IP address for %s", ss);
2811 /* Almost all subsequent comparisons require the host name, and can be done
2812 using the general string matching function. When this function is called for
2813 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2814 must use sender_host_name and its aliases, looking them up if necessary. */
2816 if (cb->host_name != NULL) /* Explicit host name given */
2817 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2820 /* Host name not given; in principle we need the sender host name and its
2821 aliases. However, for query-style lookups, we do not need the name if the
2822 query does not contain $sender_host_name. From release 4.23, a reference to
2823 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2826 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2829 int partial, affixlen, starflags, id;
2832 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2835 if (id < 0) /* Unknown lookup type */
2837 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2838 search_error_message, ss);
2841 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2846 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2849 case DEFER: return DEFER;
2850 default: return FAIL;
2854 /* Not a query-style lookup; must ensure the host name is present, and then we
2855 do a check on the name and all its aliases. */
2857 if (sender_host_name == NULL)
2859 HDEBUG(D_host_lookup)
2860 debug_printf("sender host name required, to match against %s\n", ss);
2861 if (host_lookup_failed || host_name_lookup() != OK)
2863 *error = string_sprintf("failed to find host name for %s",
2864 sender_host_address);;
2867 host_build_sender_fullhost();
2870 /* Match on the sender host name, using the general matching function */
2872 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2876 case DEFER: return DEFER;
2879 /* If there are aliases, try matching on them. */
2881 aliases = sender_host_aliases;
2882 while (*aliases != NULL)
2884 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2887 case DEFER: return DEFER;
2896 /*************************************************
2897 * Check a specific host matches a host list *
2898 *************************************************/
2900 /* This function is passed a host list containing items in a number of
2901 different formats and the identity of a host. Its job is to determine whether
2902 the given host is in the set of hosts defined by the list. The host name is
2903 passed as a pointer so that it can be looked up if needed and not already
2904 known. This is commonly the case when called from verify_check_host() to check
2905 an incoming connection. When called from elsewhere the host name should usually
2908 This function is now just a front end to match_check_list(), which runs common
2909 code for scanning a list. We pass it the check_host() function to perform a
2913 listptr pointer to the host list
2914 cache_bits pointer to cache for named lists, or NULL
2915 host_name the host name or NULL, implying use sender_host_name and
2916 sender_host_aliases, looking them up if required
2917 host_address the IP address
2918 valueptr if not NULL, data from a lookup is passed back here
2920 Returns: OK if the host is in the defined set
2921 FAIL if the host is not in the defined set,
2922 DEFER if a data lookup deferred (not a host lookup)
2924 If the host name was needed in order to make a comparison, and could not be
2925 determined from the IP address, the result is FAIL unless the item
2926 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2929 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2930 uschar *host_name, uschar *host_address, uschar **valueptr)
2933 unsigned int *local_cache_bits = cache_bits;
2934 uschar *save_host_address = deliver_host_address;
2935 check_host_block cb;
2936 cb.host_name = host_name;
2937 cb.host_address = host_address;
2939 if (valueptr != NULL) *valueptr = NULL;
2941 /* If the host address starts off ::ffff: it is an IPv6 address in
2942 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2945 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2946 host_address + 7 : host_address;
2948 /* During the running of the check, put the IP address into $host_address. In
2949 the case of calls from the smtp transport, it will already be there. However,
2950 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2951 the safe side, any existing setting is preserved, though as I write this
2952 (November 2004) I can't see any cases where it is actually needed. */
2954 deliver_host_address = host_address;
2955 rc = match_check_list(
2956 listptr, /* the list */
2957 0, /* separator character */
2958 &hostlist_anchor, /* anchor pointer */
2959 &local_cache_bits, /* cache pointer */
2960 check_host, /* function for testing */
2961 &cb, /* argument for function */
2962 MCL_HOST, /* type of check */
2963 (host_address == sender_host_address)?
2964 US"host" : host_address, /* text for debugging */
2965 valueptr); /* where to pass back data */
2966 deliver_host_address = save_host_address;
2973 /*************************************************
2974 * Check the remote host matches a list *
2975 *************************************************/
2977 /* This is a front end to verify_check_this_host(), created because checking
2978 the remote host is a common occurrence. With luck, a good compiler will spot
2979 the tail recursion and optimize it. If there's no host address, this is
2980 command-line SMTP input - check against an empty string for the address.
2983 listptr pointer to the host list
2985 Returns: the yield of verify_check_this_host(),
2986 i.e. OK, FAIL, or DEFER
2990 verify_check_host(uschar **listptr)
2992 return verify_check_this_host(listptr, sender_host_cache, NULL,
2993 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3000 /*************************************************
3001 * Invert an IP address *
3002 *************************************************/
3004 /* Originally just used for DNS xBL lists, now also used for the
3005 reverse_ip expansion operator.
3008 buffer where to put the answer
3009 address the address to invert
3013 invert_address(uschar *buffer, uschar *address)
3016 uschar *bptr = buffer;
3018 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3019 to the IPv4 part only. */
3021 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3023 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3026 if (host_aton(address, bin) == 1)
3030 for (i = 0; i < 4; i++)
3032 sprintf(CS bptr, "%d.", x & 255);
3033 while (*bptr) bptr++;
3038 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3039 in any DNS black lists, and the format in which they will be looked up is
3040 unknown. This is just a guess. */
3046 for (j = 3; j >= 0; j--)
3049 for (i = 0; i < 8; i++)
3051 sprintf(CS bptr, "%x.", x & 15);
3052 while (*bptr) bptr++;
3059 /* Remove trailing period -- this is needed so that both arbitrary
3060 dnsbl keydomains and inverted addresses may be combined with the
3061 same format string, "%s.%s" */
3068 /*************************************************
3069 * Perform a single dnsbl lookup *
3070 *************************************************/
3072 /* This function is called from verify_check_dnsbl() below. It is also called
3073 recursively from within itself when domain and domain_txt are different
3074 pointers, in order to get the TXT record from the alternate domain.
3077 domain the outer dnsbl domain
3078 domain_txt alternate domain to lookup TXT record on success; when the
3079 same domain is to be used, domain_txt == domain (that is,
3080 the pointers must be identical, not just the text)
3081 keydomain the current keydomain (for debug message)
3082 prepend subdomain to lookup (like keydomain, but
3083 reversed if IP address)
3084 iplist the list of matching IP addresses, or NULL for "any"
3085 bitmask true if bitmask matching is wanted
3086 match_type condition for 'succeed' result
3087 0 => Any RR in iplist (=)
3088 1 => No RR in iplist (!=)
3089 2 => All RRs in iplist (==)
3090 3 => Some RRs not in iplist (!==)
3091 the two bits are defined as MT_NOT and MT_ALL
3092 defer_return what to return for a defer
3094 Returns: OK if lookup succeeded
3099 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3100 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3106 dnsbl_cache_block *cb;
3107 int old_pool = store_pool;
3108 uschar query[256]; /* DNS domain max length */
3110 /* Construct the specific query domainname */
3112 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3114 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3115 "(ignored): %s...", query);
3119 /* Look for this query in the cache. */
3121 t = tree_search(dnsbl_cache, query);
3123 /* If not cached from a previous lookup, we must do a DNS lookup, and
3124 cache the result in permanent memory. */
3128 store_pool = POOL_PERM;
3130 /* Set up a tree entry to cache the lookup */
3132 t = store_get(sizeof(tree_node) + Ustrlen(query));
3133 Ustrcpy(t->name, query);
3134 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3135 (void)tree_insertnode(&dnsbl_cache, t);
3137 /* Do the DNS loopup . */
3139 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3140 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3141 cb->text_set = FALSE;
3145 /* If the lookup succeeded, cache the RHS address. The code allows for
3146 more than one address - this was for complete generality and the possible
3147 use of A6 records. However, A6 records have been reduced to experimental
3148 status (August 2001) and may die out. So they may never get used at all,
3149 let alone in dnsbl records. However, leave the code here, just in case.
3151 Quite apart from one A6 RR generating multiple addresses, there are DNS
3152 lists that return more than one A record, so we must handle multiple
3153 addresses generated in that way as well. */
3155 if (cb->rc == DNS_SUCCEED)
3158 dns_address **addrp = &(cb->rhs);
3159 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3161 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3163 if (rr->type == T_A)
3165 dns_address *da = dns_address_from_rr(&dnsa, rr);
3169 while (da->next != NULL) da = da->next;
3170 addrp = &(da->next);
3175 /* If we didn't find any A records, change the return code. This can
3176 happen when there is a CNAME record but there are no A records for what
3179 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3182 store_pool = old_pool;
3185 /* Previous lookup was cached */
3189 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3193 /* We now have the result of the DNS lookup, either newly done, or cached
3194 from a previous call. If the lookup succeeded, check against the address
3195 list if there is one. This may be a positive equality list (introduced by
3196 "="), a negative equality list (introduced by "!="), a positive bitmask
3197 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3199 if (cb->rc == DNS_SUCCEED)
3201 dns_address *da = NULL;
3202 uschar *addlist = cb->rhs->address;
3204 /* For A and AAAA records, there may be multiple addresses from multiple
3205 records. For A6 records (currently not expected to be used) there may be
3206 multiple addresses from a single record. */
3208 for (da = cb->rhs->next; da != NULL; da = da->next)
3209 addlist = string_sprintf("%s, %s", addlist, da->address);
3211 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3214 /* Address list check; this can be either for equality, or via a bitmask.
3215 In the latter case, all the bits must match. */
3219 for (da = cb->rhs; da != NULL; da = da->next)
3223 uschar *ptr = iplist;
3226 /* Handle exact matching */
3230 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3232 if (Ustrcmp(CS da->address, ip) == 0) break;
3236 /* Handle bitmask matching */
3243 /* At present, all known DNS blocking lists use A records, with
3244 IPv4 addresses on the RHS encoding the information they return. I
3245 wonder if this will linger on as the last vestige of IPv4 when IPv6
3246 is ubiquitous? Anyway, for now we use paranoia code to completely
3247 ignore IPv6 addresses. The default mask is 0, which always matches.
3248 We change this only for IPv4 addresses in the list. */
3250 if (host_aton(da->address, address) == 1) mask = address[0];
3252 /* Scan the returned addresses, skipping any that are IPv6 */
3254 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3256 if (host_aton(ip, address) != 1) continue;
3257 if ((address[0] & mask) == address[0]) break;
3263 (a) An IP address in an any ('=') list matched, or
3264 (b) No IP address in an all ('==') list matched
3266 then we're done searching. */
3268 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3271 /* If da == NULL, either
3273 (a) No IP address in an any ('=') list matched, or
3274 (b) An IP address in an all ('==') list didn't match
3276 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3279 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3287 res = US"was no match";
3290 res = US"was an exclude match";
3293 res = US"was an IP address that did not match";
3296 res = US"were no IP addresses that did not match";
3299 debug_printf("=> but we are not accepting this block class because\n");
3300 debug_printf("=> there %s for %s%c%s\n",
3302 ((match_type & MT_ALL) == 0)? "" : "=",
3303 bitmask? '&' : '=', iplist);
3309 /* Either there was no IP list, or the record matched, implying that the
3310 domain is on the list. We now want to find a corresponding TXT record. If an
3311 alternate domain is specified for the TXT record, call this function
3312 recursively to look that up; this has the side effect of re-checking that
3313 there is indeed an A record at the alternate domain. */
3315 if (domain_txt != domain)
3316 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3317 FALSE, match_type, defer_return);
3319 /* If there is no alternate domain, look up a TXT record in the main domain
3320 if it has not previously been cached. */
3324 cb->text_set = TRUE;
3325 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3328 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3330 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3331 if (rr->type == T_TXT) break;
3334 int len = (rr->data)[0];
3335 if (len > 511) len = 127;
3336 store_pool = POOL_PERM;
3337 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3338 store_pool = old_pool;
3343 dnslist_value = addlist;
3344 dnslist_text = cb->text;
3348 /* There was a problem with the DNS lookup */
3350 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3352 log_write(L_dnslist_defer, LOG_MAIN,
3353 "DNS list lookup defer (probably timeout) for %s: %s", query,
3354 (defer_return == OK)? US"assumed in list" :
3355 (defer_return == FAIL)? US"assumed not in list" :
3356 US"returned DEFER");
3357 return defer_return;
3360 /* No entry was found in the DNS; continue for next domain */
3364 debug_printf("DNS lookup for %s failed\n", query);
3365 debug_printf("=> that means %s is not listed at %s\n",
3375 /*************************************************
3376 * Check host against DNS black lists *
3377 *************************************************/
3379 /* This function runs checks against a list of DNS black lists, until one
3380 matches. Each item on the list can be of the form
3382 domain=ip-address/key
3384 The domain is the right-most domain that is used for the query, for example,
3385 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3386 if the DNS lookup returns a matching IP address. Several addresses may be
3387 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3389 If no key is given, what is looked up in the domain is the inverted IP address
3390 of the current client host. If a key is given, it is used to construct the
3391 domain for the lookup. For example:
3393 dsn.rfc-ignorant.org/$sender_address_domain
3395 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3396 then we check for a TXT record for an error message, and if found, save its
3397 value in $dnslist_text. We also cache everything in a tree, to optimize
3400 The TXT record is normally looked up in the same domain as the A record, but
3401 when many lists are combined in a single DNS domain, this will not be a very
3402 specific message. It is possible to specify a different domain for looking up
3403 TXT records; this is given before the main domain, comma-separated. For
3406 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3407 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3409 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3411 Note: an address for testing RBL is 192.203.178.39
3412 Note: an address for testing DUL is 192.203.178.4
3413 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3416 listptr the domain/address/data list
3418 Returns: OK successful lookup (i.e. the address is on the list), or
3419 lookup deferred after +include_unknown
3420 FAIL name not found, or no data found for the given type, or
3421 lookup deferred after +exclude_unknown (default)
3422 DEFER lookup failure, if +defer_unknown was set
3426 verify_check_dnsbl(uschar **listptr)
3429 int defer_return = FAIL;
3430 uschar *list = *listptr;
3433 uschar buffer[1024];
3434 uschar revadd[128]; /* Long enough for IPv6 address */
3436 /* Indicate that the inverted IP address is not yet set up */
3440 /* In case this is the first time the DNS resolver is being used. */
3442 dns_init(FALSE, FALSE);
3444 /* Loop through all the domains supplied, until something matches */
3446 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3449 BOOL bitmask = FALSE;
3456 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3458 /* Deal with special values that change the behaviour on defer */
3460 if (domain[0] == '+')
3462 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3463 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3464 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3466 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3471 /* See if there's explicit data to be looked up */
3473 key = Ustrchr(domain, '/');
3474 if (key != NULL) *key++ = 0;
3476 /* See if there's a list of addresses supplied after the domain name. This is
3477 introduced by an = or a & character; if preceded by = we require all matches
3478 and if preceded by ! we invert the result. */
3480 iplist = Ustrchr(domain, '=');
3484 iplist = Ustrchr(domain, '&');
3487 if (iplist != NULL) /* Found either = or & */
3489 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3491 match_type |= MT_NOT;
3495 *iplist++ = 0; /* Terminate domain, move on */
3497 /* If we found = (bitmask == FALSE), check for == or =& */
3499 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3501 bitmask = *iplist++ == '&';
3502 match_type |= MT_ALL;
3506 /* If there is a comma in the domain, it indicates that a second domain for
3507 looking up TXT records is provided, before the main domain. Otherwise we must
3508 set domain_txt == domain. */
3510 domain_txt = domain;
3511 comma = Ustrchr(domain, ',');
3518 /* Check that what we have left is a sensible domain name. There is no reason
3519 why these domains should in fact use the same syntax as hosts and email
3520 domains, but in practice they seem to. However, there is little point in
3521 actually causing an error here, because that would no doubt hold up incoming
3522 mail. Instead, I'll just log it. */
3524 for (s = domain; *s != 0; s++)
3526 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3528 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3529 "strange characters - is this right?", domain);
3534 /* Check the alternate domain if present */
3536 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3538 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3540 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3541 "strange characters - is this right?", domain_txt);
3546 /* If there is no key string, construct the query by adding the domain name
3547 onto the inverted host address, and perform a single DNS lookup. */
3551 if (sender_host_address == NULL) return FAIL; /* can never match */
3552 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3553 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3554 iplist, bitmask, match_type, defer_return);
3557 dnslist_domain = string_copy(domain_txt);
3558 dnslist_matched = string_copy(sender_host_address);
3559 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3560 sender_host_address, dnslist_domain);
3562 if (rc != FAIL) return rc; /* OK or DEFER */
3565 /* If there is a key string, it can be a list of domains or IP addresses to
3566 be concatenated with the main domain. */
3573 uschar keybuffer[256];
3574 uschar keyrevadd[128];
3576 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3577 sizeof(keybuffer))) != NULL)
3579 uschar *prepend = keydomain;
3581 if (string_is_ip_address(keydomain, NULL) != 0)
3583 invert_address(keyrevadd, keydomain);
3584 prepend = keyrevadd;
3587 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3588 bitmask, match_type, defer_return);
3592 dnslist_domain = string_copy(domain_txt);
3593 dnslist_matched = string_copy(keydomain);
3594 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3595 keydomain, dnslist_domain);
3599 /* If the lookup deferred, remember this fact. We keep trying the rest
3600 of the list to see if we get a useful result, and if we don't, we return
3601 DEFER at the end. */
3603 if (rc == DEFER) defer = TRUE;
3604 } /* continue with next keystring domain/address */
3606 if (defer) return DEFER;
3608 } /* continue with next dnsdb outer domain */
3613 /* End of verify.c */