1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 address_item cutthrough_addr;
18 static smtp_outblock ctblock;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if ((options & vopt_callout_recipsender) != 0)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if ((options & vopt_callout_recippmaster) != 0)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
378 smtp_transport_options_block *ob =
379 (smtp_transport_options_block *)(addr->transport->options_block);
381 /* The information wasn't available in the cache, so we have to do a real
382 callout and save the result in the cache for next time, unless no_cache is set,
383 or unless we have a previously cached negative random result. If we are to test
384 with a random local part, ensure that such a local part is available. If not,
385 log the fact, but carry on without randomming. */
387 if (callout_random && callout_random_local_part != NULL)
389 random_local_part = expand_string(callout_random_local_part);
390 if (random_local_part == NULL)
391 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
392 "callout_random_local_part: %s", expand_string_message);
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
408 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
410 /* Now make connections to the hosts and do real callouts. The list of hosts
411 is passed in as an argument. */
413 for (host = host_list; host != NULL && !done; host = host->next)
415 smtp_inblock inblock;
416 smtp_outblock outblock;
419 BOOL send_quit = TRUE;
420 uschar *active_hostname = smtp_active_hostname;
424 BOOL suppress_tls = FALSE;
425 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
426 uschar inbuffer[4096];
427 uschar outbuffer[1024];
428 uschar responsebuffer[4096];
430 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
431 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
433 /* Skip this host if we don't have an IP address for it. */
435 if (host->address == NULL)
437 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
442 /* Check the overall callout timeout */
444 if (time(NULL) - callout_start_time >= callout_overall)
446 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
450 /* Set IPv4 or IPv6 */
452 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
454 /* Expand and interpret the interface and port strings. The latter will not
455 be used if there is a host-specific port (e.g. from a manualroute router).
456 This has to be delayed till now, because they may expand differently for
457 different hosts. If there's a failure, log it, but carry on with the
460 deliver_host = host->name;
461 deliver_host_address = host->address;
462 deliver_domain = addr->domain;
464 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
466 !smtp_get_port(tf->port, addr, &port, US"callout"))
467 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
470 /* Set HELO string according to the protocol */
471 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
472 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
475 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
477 /* Set up the buffer for reading SMTP response packets. */
479 inblock.buffer = inbuffer;
480 inblock.buffersize = sizeof(inbuffer);
481 inblock.ptr = inbuffer;
482 inblock.ptrend = inbuffer;
484 /* Set up the buffer for holding SMTP commands while pipelining */
486 outblock.buffer = outbuffer;
487 outblock.buffersize = sizeof(outbuffer);
488 outblock.ptr = outbuffer;
489 outblock.cmd_count = 0;
490 outblock.authenticating = FALSE;
492 /* Reset the parameters of a TLS session */
493 tls_out.cipher = tls_out.peerdn = NULL;
495 /* Connect to the host; on failure, just loop for the next one, but we
496 set the error for the last one. Use the callout_connect timeout. */
498 tls_retry_connection:
500 inblock.sock = outblock.sock =
501 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
502 /* reconsider DSCP here */
503 if (inblock.sock < 0)
505 addr->message = string_sprintf("could not connect to %s [%s]: %s",
506 host->name, host->address, strerror(errno));
507 deliver_host = deliver_host_address = NULL;
508 deliver_domain = save_deliver_domain;
512 /* Expand the helo_data string to find the host name to use. */
514 if (tf->helo_data != NULL)
516 uschar *s = expand_string(tf->helo_data);
518 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
519 "helo_data value for callout: %s", addr->address,
520 expand_string_message);
521 else active_hostname = s;
524 deliver_host = deliver_host_address = NULL;
525 deliver_domain = save_deliver_domain;
527 /* Wait for initial response, and send HELO. The smtp_write_command()
528 function leaves its command in big_buffer. This is used in error responses.
529 Initialize it in case the connection is rejected. */
531 Ustrcpy(big_buffer, "initial connection");
533 /* Unless ssl-on-connect, wait for the initial greeting */
537 if (!smtps || (smtps && tls_out.active >= 0))
539 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
540 goto RESPONSE_FAILED;
542 /* Not worth checking greeting line for ESMTP support */
543 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
544 host->name, host->address, NULL) != OK))
546 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
551 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
554 ob->tls_tempfail_tryclear = FALSE;
556 else /* all other cases */
561 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
562 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
564 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
566 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
569 goto RESPONSE_FAILED;
575 goto esmtp_retry; /* fallback to HELO */
578 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
580 if (esmtp && !suppress_tls && tls_out.active < 0)
582 if (regex_STARTTLS == NULL) regex_STARTTLS =
583 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
585 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
586 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
593 /* If TLS is available on this connection attempt to
594 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
595 send another EHLO - the server may give a different answer in secure mode. We
596 use a separate buffer for reading the response to STARTTLS so that if it is
597 negative, the original EHLO data is available for subsequent analysis, should
598 the client not be required to use TLS. If the response is bad, copy the buffer
599 for error analysis. */
603 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
604 host->address, NULL) != OK &&
605 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
606 host->address, NULL) != OK
609 uschar buffer2[4096];
611 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
614 /* If there is an I/O error, transmission of this message is deferred. If
615 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
616 false, we also defer. However, if there is a temporary rejection of STARTTLS
617 and tls_tempfail_tryclear is true, or if there is an outright rejection of
618 STARTTLS, we carry on. This means we will try to send the message in clear,
619 unless the host is in hosts_require_tls (tested below). */
621 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
622 ob->command_timeout))
624 if (errno != 0 || buffer2[0] == 0 ||
625 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
627 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
629 goto RESPONSE_FAILED;
633 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
636 int rc = tls_client_start(inblock.sock, host, addr,
637 ob->tls_certificate, ob->tls_privatekey,
639 ob->tls_verify_certificates, ob->tls_crl,
640 ob->tls_require_ciphers,
641 #ifdef EXPERIMENTAL_OCSP
642 ob->hosts_require_ocsp,
644 ob->tls_dh_min_bits, callout);
646 /* TLS negotiation failed; give an error. Try in clear on a new connection,
647 if the options permit it for this host. */
650 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
651 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
652 host->address, NULL) != OK)
654 (void)close(inblock.sock);
655 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
656 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
658 goto tls_retry_connection;
660 /*save_errno = ERRNO_TLSFAILURE;*/
661 /*message = US"failure while setting up TLS session";*/
667 /* TLS session is set up. Copy info for logging. */
668 addr->cipher = tls_out.cipher;
669 addr->peerdn = tls_out.peerdn;
671 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
673 goto smtps_redo_greeting;
675 /* For STARTTLS we need to redo EHLO */
680 /* If the host is required to use a secure channel, ensure that we have one. */
681 if (tls_out.active < 0)
682 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
683 host->address, NULL) == OK)
685 /*save_errno = ERRNO_TLSREQUIRED;*/
686 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
687 host->name, host->address,
688 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
693 #endif /*SUPPORT_TLS*/
695 done = TRUE; /* so far so good; have response to HELO */
697 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING, AUTH */
698 /* If we haven't authenticated, but are required to, give up. */
700 /*XXX "filter command specified for this transport" ??? */
701 /* for now, transport_filter by cutthrough-delivery is not supported */
702 /* Need proper integration with the proper transport mechanism. */
709 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
712 /* Failure to accept HELO is cached; this blocks the whole domain for all
713 senders. I/O errors and defer responses are not cached. */
717 *failure_ptr = US"mail"; /* At or before MAIL */
718 if (errno == 0 && responsebuffer[0] == '5')
720 setflag(addr, af_verify_nsfail);
721 new_domain_record.result = ccache_reject;
727 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
728 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
730 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
731 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob) &&
733 /* Send the MAIL command */
735 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
736 from_address, responsebuffer) >= 0 &&
737 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
740 /* If the host does not accept MAIL FROM:<>, arrange to cache this
741 information, but again, don't record anything for an I/O error or a defer. Do
742 not cache rejections of MAIL when a non-empty sender has been used, because
743 that blocks the whole domain for all senders. */
747 *failure_ptr = US"mail"; /* At or before MAIL */
748 if (errno == 0 && responsebuffer[0] == '5')
750 setflag(addr, af_verify_nsfail);
751 if (from_address[0] == 0)
752 new_domain_record.result = ccache_reject_mfnull;
756 /* Otherwise, proceed to check a "random" address (if required), then the
757 given address, and the postmaster address (if required). Between each check,
758 issue RSET, because some servers accept only one recipient after MAIL
761 Before doing this, set the result in the domain cache record to "accept",
762 unless its previous value was ccache_reject_mfnull. In that case, the domain
763 rejects MAIL FROM:<> and we want to continue to remember that. When that is
764 the case, we have got here only in the case of a recipient verification with
765 a non-null sender. */
769 new_domain_record.result =
770 (old_domain_cache_result == ccache_reject_mfnull)?
771 ccache_reject_mfnull: ccache_accept;
773 /* Do the random local part check first */
775 if (random_local_part != NULL)
777 uschar randombuffer[1024];
779 smtp_write_command(&outblock, FALSE,
780 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
781 addr->domain) >= 0 &&
782 smtp_read_response(&inblock, randombuffer,
783 sizeof(randombuffer), '2', callout);
785 /* Remember when we last did a random test */
787 new_domain_record.random_stamp = time(NULL);
789 /* If accepted, we aren't going to do any further tests below. */
793 new_domain_record.random_result = ccache_accept;
796 /* Otherwise, cache a real negative response, and get back to the right
797 state to send RCPT. Unless there's some problem such as a dropped
798 connection, we expect to succeed, because the commands succeeded above. */
802 if (randombuffer[0] == '5')
803 new_domain_record.random_result = ccache_reject;
806 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
807 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
810 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
811 from_address) >= 0 &&
812 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
815 else done = FALSE; /* Some timeout/connection problem */
818 /* If the host is accepting all local parts, as determined by the "random"
819 check, we don't need to waste time doing any further checking. */
821 if (new_domain_record.random_result != ccache_accept && done)
823 /* Get the rcpt_include_affixes flag from the transport if there is one,
824 but assume FALSE if there is not. */
827 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
828 transport_rcpt_address(addr,
829 (addr->transport == NULL)? FALSE :
830 addr->transport->rcpt_include_affixes)) >= 0 &&
831 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
835 new_address_record.result = ccache_accept;
836 else if (errno == 0 && responsebuffer[0] == '5')
838 *failure_ptr = US"recipient";
839 new_address_record.result = ccache_reject;
842 /* Do postmaster check if requested; if a full check is required, we
843 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
845 if (done && pm_mailfrom != NULL)
847 /*XXX not suitable for cutthrough - sequencing problems */
848 cutthrough_delivery= FALSE;
849 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
852 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
853 smtp_read_response(&inblock, responsebuffer,
854 sizeof(responsebuffer), '2', callout) &&
856 smtp_write_command(&outblock, FALSE,
857 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
858 smtp_read_response(&inblock, responsebuffer,
859 sizeof(responsebuffer), '2', callout) &&
861 /* First try using the current domain */
864 smtp_write_command(&outblock, FALSE,
865 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
866 smtp_read_response(&inblock, responsebuffer,
867 sizeof(responsebuffer), '2', callout)
872 /* If that doesn't work, and a full check is requested,
873 try without the domain. */
876 (options & vopt_callout_fullpm) != 0 &&
877 smtp_write_command(&outblock, FALSE,
878 "RCPT TO:<postmaster>\r\n") >= 0 &&
879 smtp_read_response(&inblock, responsebuffer,
880 sizeof(responsebuffer), '2', callout)
883 /* Sort out the cache record */
885 new_domain_record.postmaster_stamp = time(NULL);
888 new_domain_record.postmaster_result = ccache_accept;
889 else if (errno == 0 && responsebuffer[0] == '5')
891 *failure_ptr = US"postmaster";
892 setflag(addr, af_verify_pmfail);
893 new_domain_record.postmaster_result = ccache_reject;
896 } /* Random not accepted */
897 } /* MAIL FROM: accepted */
899 /* For any failure of the main check, other than a negative response, we just
900 close the connection and carry on. We can identify a negative response by the
901 fact that errno is zero. For I/O errors it will be non-zero
903 Set up different error texts for logging and for sending back to the caller
904 as an SMTP response. Log in all cases, using a one-line format. For sender
905 callouts, give a full response to the caller, but for recipient callouts,
906 don't give the IP address because this may be an internal host whose identity
907 is not to be widely broadcast. */
911 if (errno == ETIMEDOUT)
913 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
918 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
921 string_sprintf("response to \"%s\" from %s [%s] was: %s",
922 big_buffer, host->name, host->address,
923 string_printing(responsebuffer));
925 addr->user_message = is_recipient?
926 string_sprintf("Callout verification failed:\n%s", responsebuffer)
928 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
929 host->address, big_buffer, responsebuffer);
931 /* Hard rejection ends the process */
933 if (responsebuffer[0] == '5') /* Address rejected */
941 /* End the SMTP conversation and close the connection. */
943 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
944 and we have no cutthrough conn so far
945 here is where we want to leave the conn open */
946 if ( cutthrough_delivery
949 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
950 && !random_local_part
955 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
956 cutthrough_addr = *addr; /* Save the address_item for later logging */
957 cutthrough_addr.host_used = store_get(sizeof(host_item));
958 cutthrough_addr.host_used->name = host->name;
959 cutthrough_addr.host_used->address = host->address;
960 cutthrough_addr.host_used->port = port;
962 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
963 ctblock.buffer = ctbuffer;
964 ctblock.buffersize = sizeof(ctbuffer);
965 ctblock.ptr = ctbuffer;
966 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
967 ctblock.sock = cutthrough_fd;
971 /* Ensure no cutthrough on multiple address verifies */
972 if (options & vopt_callout_recipsender)
973 cancel_cutthrough_connection("multiple verify calls");
974 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
977 tls_close(FALSE, TRUE);
979 (void)close(inblock.sock);
982 } /* Loop through all hosts, while !done */
985 /* If we get here with done == TRUE, a successful callout happened, and yield
986 will be set OK or FAIL according to the response to the RCPT command.
987 Otherwise, we looped through the hosts but couldn't complete the business.
988 However, there may be domain-specific information to cache in both cases.
990 The value of the result field in the new_domain record is ccache_unknown if
991 there was an error before or with MAIL FROM:, and errno was not zero,
992 implying some kind of I/O error. We don't want to write the cache in that case.
993 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
995 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
997 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1000 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1004 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1005 (int)sizeof(dbdata_callout_cache));
1006 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1007 " result=%d postmaster=%d random=%d\n",
1008 new_domain_record.result,
1009 new_domain_record.postmaster_result,
1010 new_domain_record.random_result);
1014 /* If a definite result was obtained for the callout, cache it unless caching
1019 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1021 if (dbm_file == NULL)
1022 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1023 if (dbm_file == NULL)
1025 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1029 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1030 (int)sizeof(dbdata_callout_cache_address));
1031 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1032 (new_address_record.result == ccache_accept)? "positive" : "negative");
1037 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1038 temporary error. If there was only one host, and a response was received, leave
1039 it alone if supplying details. Otherwise, give a generic response. */
1043 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1044 is_recipient? "recipient" : "sender");
1047 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1049 addr->user_message = (!smtp_return_error_details)? dullmsg :
1050 string_sprintf("%s for <%s>.\n"
1051 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1052 "they may be permanently unreachable from this server. In the latter case,\n%s",
1053 dullmsg, addr->address,
1055 "the address will never be accepted."
1057 "you need to change the address or create an MX record for its domain\n"
1058 "if it is supposed to be generally accessible from the Internet.\n"
1059 "Talk to your mail administrator for details.");
1061 /* Force a specific error code */
1063 addr->basic_errno = ERRNO_CALLOUTDEFER;
1066 /* Come here from within the cache-reading code on fast-track exit. */
1069 if (dbm_file != NULL) dbfn_close(dbm_file);
1075 /* Called after recipient-acl to get a cutthrough connection open when
1076 one was requested and a recipient-verify wasn't subsequently done.
1079 open_cutthrough_connection( address_item * addr )
1083 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1084 /* We must use a copy of the address for verification, because it might
1088 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1089 (void) verify_address(&addr2, NULL,
1090 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1091 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1093 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1099 /* Send given number of bytes from the buffer */
1101 cutthrough_send(int n)
1103 if(cutthrough_fd < 0)
1108 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1110 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1113 transport_count += n;
1114 ctblock.ptr= ctblock.buffer;
1118 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1125 _cutthrough_puts(uschar * cp, int n)
1129 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1130 if(!cutthrough_send(ctblock.buffersize))
1133 *ctblock.ptr++ = *cp++;
1138 /* Buffered output of counted data block. Return boolean success */
1140 cutthrough_puts(uschar * cp, int n)
1142 if (cutthrough_fd < 0) return TRUE;
1143 if (_cutthrough_puts(cp, n)) return TRUE;
1144 cancel_cutthrough_connection("transmit failed");
1150 _cutthrough_flush_send( void )
1152 int n= ctblock.ptr-ctblock.buffer;
1155 if(!cutthrough_send(n))
1161 /* Send out any bufferred output. Return boolean success. */
1163 cutthrough_flush_send( void )
1165 if (_cutthrough_flush_send()) return TRUE;
1166 cancel_cutthrough_connection("transmit failed");
1172 cutthrough_put_nl( void )
1174 return cutthrough_puts(US"\r\n", 2);
1178 /* Get and check response from cutthrough target */
1180 cutthrough_response(char expect, uschar ** copy)
1182 smtp_inblock inblock;
1183 uschar inbuffer[4096];
1184 uschar responsebuffer[4096];
1186 inblock.buffer = inbuffer;
1187 inblock.buffersize = sizeof(inbuffer);
1188 inblock.ptr = inbuffer;
1189 inblock.ptrend = inbuffer;
1190 inblock.sock = cutthrough_fd;
1191 /* this relies on (inblock.sock == tls_out.active) */
1192 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1193 cancel_cutthrough_connection("target timeout on read");
1198 *copy= cp= string_copy(responsebuffer);
1199 /* Trim the trailing end of line */
1200 cp += Ustrlen(responsebuffer);
1201 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1202 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1205 return responsebuffer[0];
1209 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1211 cutthrough_predata( void )
1213 if(cutthrough_fd < 0)
1216 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1217 cutthrough_puts(US"DATA\r\n", 6);
1218 cutthrough_flush_send();
1220 /* Assume nothing buffered. If it was it gets ignored. */
1221 return cutthrough_response('3', NULL) == '3';
1225 /* Buffered send of headers. Return success boolean. */
1226 /* Expands newlines to wire format (CR,NL). */
1227 /* Also sends header-terminating blank line. */
1229 cutthrough_headers_send( void )
1232 uschar * cp1, * cp2;
1234 if(cutthrough_fd < 0)
1237 for(h= header_list; h != NULL; h= h->next)
1238 if(h->type != htype_old && h->text != NULL)
1239 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1240 if( !cutthrough_puts(cp1, cp2-cp1)
1241 || !cutthrough_put_nl())
1244 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1245 return cutthrough_put_nl();
1250 close_cutthrough_connection( const char * why )
1252 if(cutthrough_fd >= 0)
1254 /* We could be sending this after a bunch of data, but that is ok as
1255 the only way to cancel the transfer in dataphase is to drop the tcp
1256 conn before the final dot.
1258 ctblock.ptr = ctbuffer;
1259 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1260 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1261 _cutthrough_flush_send();
1262 /* No wait for response */
1265 tls_close(FALSE, TRUE);
1267 (void)close(cutthrough_fd);
1269 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1271 ctblock.ptr = ctbuffer;
1275 cancel_cutthrough_connection( const char * why )
1277 close_cutthrough_connection(why);
1278 cutthrough_delivery= FALSE;
1284 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1285 Log an OK response as a transmission.
1286 Close the connection.
1287 Return smtp response-class digit.
1290 cutthrough_finaldot( void )
1292 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1294 /* Assume data finshed with new-line */
1295 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1296 return cutthrough_addr.message;
1298 switch(cutthrough_response('2', &cutthrough_addr.message))
1301 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1302 close_cutthrough_connection("delivered");
1306 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1310 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1316 return cutthrough_addr.message;
1321 /*************************************************
1322 * Copy error to toplevel address *
1323 *************************************************/
1325 /* This function is used when a verify fails or defers, to ensure that the
1326 failure or defer information is in the original toplevel address. This applies
1327 when an address is redirected to a single new address, and the failure or
1328 deferral happens to the child address.
1331 vaddr the verify address item
1332 addr the final address item
1335 Returns: the value of YIELD
1339 copy_error(address_item *vaddr, address_item *addr, int yield)
1343 vaddr->message = addr->message;
1344 vaddr->user_message = addr->user_message;
1345 vaddr->basic_errno = addr->basic_errno;
1346 vaddr->more_errno = addr->more_errno;
1347 vaddr->p.address_data = addr->p.address_data;
1348 copyflag(vaddr, addr, af_pass_message);
1356 /**************************************************
1357 * printf that automatically handles TLS if needed *
1358 ***************************************************/
1360 /* This function is used by verify_address() as a substitute for all fprintf()
1361 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1362 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1363 that assumes that we always use the smtp_out FILE* when not using TLS or the
1364 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1365 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1369 f the candidate FILE* to write to
1370 format format string
1371 ... optional arguments
1377 static void PRINTF_FUNCTION(2,3)
1378 respond_printf(FILE *f, const char *format, ...)
1382 va_start(ap, format);
1383 if (smtp_out && (f == smtp_out))
1384 smtp_vprintf(format, ap);
1386 vfprintf(f, format, ap);
1392 /*************************************************
1393 * Verify an email address *
1394 *************************************************/
1396 /* This function is used both for verification (-bv and at other times) and
1397 address testing (-bt), which is indicated by address_test_mode being set.
1400 vaddr contains the address to verify; the next field in this block
1402 f if not NULL, write the result to this file
1403 options various option bits:
1404 vopt_fake_sender => this sender verify is not for the real
1405 sender (it was verify=sender=xxxx or an address from a
1406 header line) - rewriting must not change sender_address
1407 vopt_is_recipient => this is a recipient address, otherwise
1408 it's a sender address - this affects qualification and
1409 rewriting and messages from callouts
1410 vopt_qualify => qualify an unqualified address; else error
1411 vopt_expn => called from SMTP EXPN command
1412 vopt_success_on_redirect => when a new address is generated
1413 the verification instantly succeeds
1415 These ones are used by do_callout() -- the options variable
1418 vopt_callout_fullpm => if postmaster check, do full one
1419 vopt_callout_no_cache => don't use callout cache
1420 vopt_callout_random => do the "random" thing
1421 vopt_callout_recipsender => use real sender for recipient
1422 vopt_callout_recippmaster => use postmaster for recipient
1424 callout if > 0, specifies that callout is required, and gives timeout
1425 for individual commands
1426 callout_overall if > 0, gives overall timeout for the callout function;
1427 if < 0, a default is used (see do_callout())
1428 callout_connect the connection timeout for callouts
1429 se_mailfrom when callout is requested to verify a sender, use this
1430 in MAIL FROM; NULL => ""
1431 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1432 thing and use this as the sender address (may be "")
1434 routed if not NULL, set TRUE if routing succeeded, so we can
1435 distinguish between routing failed and callout failed
1437 Returns: OK address verified
1438 FAIL address failed to verify
1439 DEFER can't tell at present
1443 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1444 int callout_overall, int callout_connect, uschar *se_mailfrom,
1445 uschar *pm_mailfrom, BOOL *routed)
1448 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1449 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1450 BOOL expn = (options & vopt_expn) != 0;
1451 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1454 int verify_type = expn? v_expn :
1455 address_test_mode? v_none :
1456 is_recipient? v_recipient : v_sender;
1457 address_item *addr_list;
1458 address_item *addr_new = NULL;
1459 address_item *addr_remote = NULL;
1460 address_item *addr_local = NULL;
1461 address_item *addr_succeed = NULL;
1462 uschar **failure_ptr = is_recipient?
1463 &recipient_verify_failure : &sender_verify_failure;
1464 uschar *ko_prefix, *cr;
1465 uschar *address = vaddr->address;
1466 uschar *save_sender;
1467 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1469 /* Clear, just in case */
1471 *failure_ptr = NULL;
1473 /* Set up a prefix and suffix for error message which allow us to use the same
1474 output statements both in EXPN mode (where an SMTP response is needed) and when
1475 debugging with an output file. */
1479 ko_prefix = US"553 ";
1482 else ko_prefix = cr = US"";
1484 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1486 if (parse_find_at(address) == NULL)
1488 if ((options & vopt_qualify) == 0)
1491 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1492 ko_prefix, address, cr);
1493 *failure_ptr = US"qualify";
1496 address = rewrite_address_qualify(address, is_recipient);
1501 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1502 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1505 /* Rewrite and report on it. Clear the domain and local part caches - these
1506 may have been set by domains and local part tests during an ACL. */
1508 if (global_rewrite_rules != NULL)
1510 uschar *old = address;
1511 address = rewrite_address(address, is_recipient, FALSE,
1512 global_rewrite_rules, rewrite_existflags);
1515 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1516 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1517 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1521 /* If this is the real sender address, we must update sender_address at
1522 this point, because it may be referred to in the routers. */
1524 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1525 sender_address = address;
1527 /* If the address was rewritten to <> no verification can be done, and we have
1528 to return OK. This rewriting is permitted only for sender addresses; for other
1529 addresses, such rewriting fails. */
1531 if (address[0] == 0) return OK;
1533 /* Flip the legacy TLS-related variables over to the outbound set in case
1534 they're used in the context of a transport used by verification. Reset them
1535 at exit from this routine. */
1537 modify_variable(US"tls_bits", &tls_out.bits);
1538 modify_variable(US"tls_certificate_verified", &tls_out.certificate_verified);
1539 modify_variable(US"tls_cipher", &tls_out.cipher);
1540 modify_variable(US"tls_peerdn", &tls_out.peerdn);
1541 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1542 modify_variable(US"tls_sni", &tls_out.sni);
1545 /* Save a copy of the sender address for re-instating if we change it to <>
1546 while verifying a sender address (a nice bit of self-reference there). */
1548 save_sender = sender_address;
1550 /* Update the address structure with the possibly qualified and rewritten
1551 address. Set it up as the starting address on the chain of new addresses. */
1553 vaddr->address = address;
1556 /* We need a loop, because an address can generate new addresses. We must also
1557 cope with generated pipes and files at the top level. (See also the code and
1558 comment in deliver.c.) However, it is usually the case that the router for
1559 user's .forward files has its verify flag turned off.
1561 If an address generates more than one child, the loop is used only when
1562 full_info is set, and this can only be set locally. Remote enquiries just get
1563 information about the top level address, not anything that it generated. */
1565 while (addr_new != NULL)
1568 address_item *addr = addr_new;
1570 addr_new = addr->next;
1575 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1576 debug_printf("Considering %s\n", addr->address);
1579 /* Handle generated pipe, file or reply addresses. We don't get these
1580 when handling EXPN, as it does only one level of expansion. */
1582 if (testflag(addr, af_pfr))
1589 if (addr->address[0] == '>')
1591 allow = testflag(addr, af_allow_reply);
1592 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1596 allow = (addr->address[0] == '|')?
1597 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1598 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1601 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1602 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1603 "%s\n", addr->message);
1605 fprintf(f, "\n transport = %s\n", addr->transport->name);
1607 fprintf(f, " *** forbidden ***\n");
1612 /* Just in case some router parameter refers to it. */
1614 return_path = (addr->p.errors_address != NULL)?
1615 addr->p.errors_address : sender_address;
1617 /* Split the address into domain and local part, handling the %-hack if
1618 necessary, and then route it. While routing a sender address, set
1619 $sender_address to <> because that is what it will be if we were trying to
1620 send a bounce to the sender. */
1622 if (routed != NULL) *routed = FALSE;
1623 if ((rc = deliver_split_address(addr)) == OK)
1625 if (!is_recipient) sender_address = null_sender;
1626 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1627 &addr_succeed, verify_type);
1628 sender_address = save_sender; /* Put back the real sender */
1631 /* If routing an address succeeded, set the flag that remembers, for use when
1632 an ACL cached a sender verify (in case a callout fails). Then if routing set
1633 up a list of hosts or the transport has a host list, and the callout option
1634 is set, and we aren't in a host checking run, do the callout verification,
1635 and set another flag that notes that a callout happened. */
1639 if (routed != NULL) *routed = TRUE;
1642 host_item *host_list = addr->host_list;
1644 /* Make up some data for use in the case where there is no remote
1647 transport_feedback tf = {
1648 NULL, /* interface (=> any) */
1649 US"smtp", /* port */
1650 US"smtp", /* protocol */
1652 US"$smtp_active_hostname", /* helo_data */
1653 FALSE, /* hosts_override */
1654 FALSE, /* hosts_randomize */
1655 FALSE, /* gethostbyname */
1656 TRUE, /* qualify_single */
1657 FALSE /* search_parents */
1660 /* If verification yielded a remote transport, we want to use that
1661 transport's options, so as to mimic what would happen if we were really
1662 sending a message to this address. */
1664 if (addr->transport != NULL && !addr->transport->info->local)
1666 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1668 /* If the transport has hosts and the router does not, or if the
1669 transport is configured to override the router's hosts, we must build a
1670 host list of the transport's hosts, and find the IP addresses */
1672 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1675 uschar *save_deliver_domain = deliver_domain;
1676 uschar *save_deliver_localpart = deliver_localpart;
1678 host_list = NULL; /* Ignore the router's hosts */
1680 deliver_domain = addr->domain;
1681 deliver_localpart = addr->local_part;
1682 s = expand_string(tf.hosts);
1683 deliver_domain = save_deliver_domain;
1684 deliver_localpart = save_deliver_localpart;
1688 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1689 "\"%s\" in %s transport for callout: %s", tf.hosts,
1690 addr->transport->name, expand_string_message);
1695 uschar *canonical_name;
1696 host_item *host, *nexthost;
1697 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1699 /* Just ignore failures to find a host address. If we don't manage
1700 to find any addresses, the callout will defer. Note that more than
1701 one address may be found for a single host, which will result in
1702 additional host items being inserted into the chain. Hence we must
1703 save the next host first. */
1705 flags = HOST_FIND_BY_A;
1706 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1707 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1709 for (host = host_list; host != NULL; host = nexthost)
1711 nexthost = host->next;
1712 if (tf.gethostbyname ||
1713 string_is_ip_address(host->name, NULL) != 0)
1714 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1716 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1717 &canonical_name, NULL);
1723 /* Can only do a callout if we have at least one host! If the callout
1724 fails, it will have set ${sender,recipient}_verify_failure. */
1726 if (host_list != NULL)
1728 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1729 if (host_checking && !host_checking_callout)
1732 debug_printf("... callout omitted by default when host testing\n"
1733 "(Use -bhc if you want the callouts to happen.)\n");
1738 deliver_set_expansions(addr);
1740 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1741 callout_connect, options, se_mailfrom, pm_mailfrom);
1746 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1747 "transport provided a host list\n");
1752 /* Otherwise, any failure is a routing failure */
1754 else *failure_ptr = US"route";
1756 /* A router may return REROUTED if it has set up a child address as a result
1757 of a change of domain name (typically from widening). In this case we always
1758 want to continue to verify the new child. */
1760 if (rc == REROUTED) continue;
1762 /* Handle hard failures */
1769 address_item *p = addr->parent;
1771 respond_printf(f, "%s%s %s", ko_prefix,
1772 full_info? addr->address : address,
1773 address_test_mode? "is undeliverable" : "failed to verify");
1774 if (!expn && admin_user)
1776 if (addr->basic_errno > 0)
1777 respond_printf(f, ": %s", strerror(addr->basic_errno));
1778 if (addr->message != NULL)
1779 respond_printf(f, ": %s", addr->message);
1782 /* Show parents iff doing full info */
1784 if (full_info) while (p != NULL)
1786 respond_printf(f, "%s\n <-- %s", cr, p->address);
1789 respond_printf(f, "%s\n", cr);
1791 cancel_cutthrough_connection("routing hard fail");
1795 yield = copy_error(vaddr, addr, FAIL);
1803 else if (rc == DEFER)
1808 address_item *p = addr->parent;
1809 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1810 full_info? addr->address : address);
1811 if (!expn && admin_user)
1813 if (addr->basic_errno > 0)
1814 respond_printf(f, ": %s", strerror(addr->basic_errno));
1815 if (addr->message != NULL)
1816 respond_printf(f, ": %s", addr->message);
1817 else if (addr->basic_errno <= 0)
1818 respond_printf(f, ": unknown error");
1821 /* Show parents iff doing full info */
1823 if (full_info) while (p != NULL)
1825 respond_printf(f, "%s\n <-- %s", cr, p->address);
1828 respond_printf(f, "%s\n", cr);
1830 cancel_cutthrough_connection("routing soft fail");
1834 yield = copy_error(vaddr, addr, DEFER);
1837 else if (yield == OK) yield = DEFER;
1840 /* If we are handling EXPN, we do not want to continue to route beyond
1841 the top level (whose address is in "address"). */
1845 uschar *ok_prefix = US"250-";
1846 if (addr_new == NULL)
1848 if (addr_local == NULL && addr_remote == NULL)
1849 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1851 respond_printf(f, "250 <%s>\r\n", address);
1853 else while (addr_new != NULL)
1855 address_item *addr2 = addr_new;
1856 addr_new = addr2->next;
1857 if (addr_new == NULL) ok_prefix = US"250 ";
1858 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1864 /* Successful routing other than EXPN. */
1868 /* Handle successful routing when short info wanted. Otherwise continue for
1869 other (generated) addresses. Short info is the operational case. Full info
1870 can be requested only when debug_selector != 0 and a file is supplied.
1872 There is a conflict between the use of aliasing as an alternate email
1873 address, and as a sort of mailing list. If an alias turns the incoming
1874 address into just one address (e.g. J.Caesar->jc44) you may well want to
1875 carry on verifying the generated address to ensure it is valid when
1876 checking incoming mail. If aliasing generates multiple addresses, you
1877 probably don't want to do this. Exim therefore treats the generation of
1878 just a single new address as a special case, and continues on to verify the
1879 generated address. */
1881 if (!full_info && /* Stop if short info wanted AND */
1882 (((addr_new == NULL || /* No new address OR */
1883 addr_new->next != NULL || /* More than one new address OR */
1884 testflag(addr_new, af_pfr))) /* New address is pfr */
1886 (addr_new != NULL && /* At least one new address AND */
1887 success_on_redirect))) /* success_on_redirect is set */
1889 if (f != NULL) fprintf(f, "%s %s\n", address,
1890 address_test_mode? "is deliverable" : "verified");
1892 /* If we have carried on to verify a child address, we want the value
1893 of $address_data to be that of the child */
1895 vaddr->p.address_data = addr->p.address_data;
1900 } /* Loop for generated addresses */
1902 /* Display the full results of the successful routing, including any generated
1903 addresses. Control gets here only when full_info is set, which requires f not
1904 to be NULL, and this occurs only when a top-level verify is called with the
1905 debugging switch on.
1907 If there are no local and no remote addresses, and there were no pipes, files,
1908 or autoreplies, and there were no errors or deferments, the message is to be
1909 discarded, usually because of the use of :blackhole: in an alias file. */
1911 if (allok && addr_local == NULL && addr_remote == NULL)
1913 fprintf(f, "mail to %s is discarded\n", address);
1917 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1919 while (addr_list != NULL)
1921 address_item *addr = addr_list;
1922 address_item *p = addr->parent;
1923 addr_list = addr->next;
1925 fprintf(f, "%s", CS addr->address);
1926 #ifdef EXPERIMENTAL_SRS
1927 if(addr->p.srs_sender)
1928 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1931 /* If the address is a duplicate, show something about it. */
1933 if (!testflag(addr, af_pfr))
1936 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1937 fprintf(f, " [duplicate, would not be delivered]");
1938 else tree_add_duplicate(addr->unique, addr);
1941 /* Now show its parents */
1945 fprintf(f, "\n <-- %s", p->address);
1950 /* Show router, and transport */
1952 fprintf(f, "router = %s, ", addr->router->name);
1953 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1954 addr->transport->name);
1956 /* Show any hosts that are set up by a router unless the transport
1957 is going to override them; fiddle a bit to get a nice format. */
1959 if (addr->host_list != NULL && addr->transport != NULL &&
1960 !addr->transport->overrides_hosts)
1965 for (h = addr->host_list; h != NULL; h = h->next)
1967 int len = Ustrlen(h->name);
1968 if (len > maxlen) maxlen = len;
1969 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1970 if (len > maxaddlen) maxaddlen = len;
1972 for (h = addr->host_list; h != NULL; h = h->next)
1974 int len = Ustrlen(h->name);
1975 fprintf(f, " host %s ", h->name);
1976 while (len++ < maxlen) fprintf(f, " ");
1977 if (h->address != NULL)
1979 fprintf(f, "[%s] ", h->address);
1980 len = Ustrlen(h->address);
1982 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1984 fprintf(f, "[unknown] ");
1988 while (len++ < maxaddlen) fprintf(f," ");
1989 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1990 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1991 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1998 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
1999 the -bv or -bt case). */
2003 modify_variable(US"tls_bits", &tls_in.bits);
2004 modify_variable(US"tls_certificate_verified", &tls_in.certificate_verified);
2005 modify_variable(US"tls_cipher", &tls_in.cipher);
2006 modify_variable(US"tls_peerdn", &tls_in.peerdn);
2007 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
2008 modify_variable(US"tls_sni", &tls_in.sni);
2017 /*************************************************
2018 * Check headers for syntax errors *
2019 *************************************************/
2021 /* This function checks those header lines that contain addresses, and verifies
2022 that all the addresses therein are syntactially correct.
2025 msgptr where to put an error message
2032 verify_check_headers(uschar **msgptr)
2038 for (h = header_list; h != NULL && yield == OK; h = h->next)
2040 if (h->type != htype_from &&
2041 h->type != htype_reply_to &&
2042 h->type != htype_sender &&
2043 h->type != htype_to &&
2044 h->type != htype_cc &&
2045 h->type != htype_bcc)
2048 colon = Ustrchr(h->text, ':');
2050 while (isspace(*s)) s++;
2052 /* Loop for multiple addresses in the header, enabling group syntax. Note
2053 that we have to reset this after the header has been scanned. */
2055 parse_allow_group = TRUE;
2059 uschar *ss = parse_find_address_end(s, FALSE);
2060 uschar *recipient, *errmess;
2061 int terminator = *ss;
2062 int start, end, domain;
2064 /* Temporarily terminate the string at this point, and extract the
2065 operative address within, allowing group syntax. */
2068 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2071 /* Permit an unqualified address only if the message is local, or if the
2072 sending host is configured to be permitted to send them. */
2074 if (recipient != NULL && domain == 0)
2076 if (h->type == htype_from || h->type == htype_sender)
2078 if (!allow_unqualified_sender) recipient = NULL;
2082 if (!allow_unqualified_recipient) recipient = NULL;
2084 if (recipient == NULL) errmess = US"unqualified address not permitted";
2087 /* It's an error if no address could be extracted, except for the special
2088 case of an empty address. */
2090 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2092 uschar *verb = US"is";
2097 /* Arrange not to include any white space at the end in the
2098 error message or the header name. */
2100 while (t > s && isspace(t[-1])) t--;
2101 while (tt > h->text && isspace(tt[-1])) tt--;
2103 /* Add the address that failed to the error message, since in a
2104 header with very many addresses it is sometimes hard to spot
2105 which one is at fault. However, limit the amount of address to
2106 quote - cases have been seen where, for example, a missing double
2107 quote in a humungous To: header creates an "address" that is longer
2108 than string_sprintf can handle. */
2117 *msgptr = string_printing(
2118 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2119 errmess, tt - h->text, h->text, verb, len, s));
2122 break; /* Out of address loop */
2125 /* Advance to the next address */
2127 s = ss + (terminator? 1:0);
2128 while (isspace(*s)) s++;
2129 } /* Next address */
2131 parse_allow_group = FALSE;
2132 parse_found_group = FALSE;
2133 } /* Next header unless yield has been set FALSE */
2140 /*************************************************
2141 * Check for blind recipients *
2142 *************************************************/
2144 /* This function checks that every (envelope) recipient is mentioned in either
2145 the To: or Cc: header lines, thus detecting blind carbon copies.
2147 There are two ways of scanning that could be used: either scan the header lines
2148 and tick off the recipients, or scan the recipients and check the header lines.
2149 The original proposed patch did the former, but I have chosen to do the latter,
2150 because (a) it requires no memory and (b) will use fewer resources when there
2151 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2154 Returns: OK if there are no blind recipients
2155 FAIL if there is at least one blind recipient
2159 verify_check_notblind(void)
2162 for (i = 0; i < recipients_count; i++)
2166 uschar *address = recipients_list[i].address;
2168 for (h = header_list; !found && h != NULL; h = h->next)
2172 if (h->type != htype_to && h->type != htype_cc) continue;
2174 colon = Ustrchr(h->text, ':');
2176 while (isspace(*s)) s++;
2178 /* Loop for multiple addresses in the header, enabling group syntax. Note
2179 that we have to reset this after the header has been scanned. */
2181 parse_allow_group = TRUE;
2185 uschar *ss = parse_find_address_end(s, FALSE);
2186 uschar *recipient,*errmess;
2187 int terminator = *ss;
2188 int start, end, domain;
2190 /* Temporarily terminate the string at this point, and extract the
2191 operative address within, allowing group syntax. */
2194 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2197 /* If we found a valid recipient that has a domain, compare it with the
2198 envelope recipient. Local parts are compared case-sensitively, domains
2199 case-insensitively. By comparing from the start with length "domain", we
2200 include the "@" at the end, which ensures that we are comparing the whole
2201 local part of each address. */
2203 if (recipient != NULL && domain != 0)
2205 found = Ustrncmp(recipient, address, domain) == 0 &&
2206 strcmpic(recipient + domain, address + domain) == 0;
2210 /* Advance to the next address */
2212 s = ss + (terminator? 1:0);
2213 while (isspace(*s)) s++;
2214 } /* Next address */
2216 parse_allow_group = FALSE;
2217 parse_found_group = FALSE;
2218 } /* Next header (if found is false) */
2220 if (!found) return FAIL;
2221 } /* Next recipient */
2228 /*************************************************
2229 * Find if verified sender *
2230 *************************************************/
2232 /* Usually, just a single address is verified as the sender of the message.
2233 However, Exim can be made to verify other addresses as well (often related in
2234 some way), and this is useful in some environments. There may therefore be a
2235 chain of such addresses that have previously been tested. This function finds
2236 whether a given address is on the chain.
2238 Arguments: the address to be verified
2239 Returns: pointer to an address item, or NULL
2243 verify_checked_sender(uschar *sender)
2246 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2247 if (Ustrcmp(sender, addr->address) == 0) break;
2255 /*************************************************
2256 * Get valid header address *
2257 *************************************************/
2259 /* Scan the originator headers of the message, looking for an address that
2260 verifies successfully. RFC 822 says:
2262 o The "Sender" field mailbox should be sent notices of
2263 any problems in transport or delivery of the original
2264 messages. If there is no "Sender" field, then the
2265 "From" field mailbox should be used.
2267 o If the "Reply-To" field exists, then the reply should
2268 go to the addresses indicated in that field and not to
2269 the address(es) indicated in the "From" field.
2271 So we check a Sender field if there is one, else a Reply_to field, else a From
2272 field. As some strange messages may have more than one of these fields,
2273 especially if they are resent- fields, check all of them if there is more than
2277 user_msgptr points to where to put a user error message
2278 log_msgptr points to where to put a log error message
2279 callout timeout for callout check (passed to verify_address())
2280 callout_overall overall callout timeout (ditto)
2281 callout_connect connect callout timeout (ditto)
2282 se_mailfrom mailfrom for verify; NULL => ""
2283 pm_mailfrom sender for pm callout check (passed to verify_address())
2284 options callout options (passed to verify_address())
2285 verrno where to put the address basic_errno
2287 If log_msgptr is set to something without setting user_msgptr, the caller
2288 normally uses log_msgptr for both things.
2290 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2291 FAIL is given if no appropriate headers are found
2295 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2296 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2297 uschar *pm_mailfrom, int options, int *verrno)
2299 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2304 for (i = 0; i < 3 && !done; i++)
2307 for (h = header_list; h != NULL && !done; h = h->next)
2309 int terminator, new_ok;
2310 uschar *s, *ss, *endname;
2312 if (h->type != header_types[i]) continue;
2313 s = endname = Ustrchr(h->text, ':') + 1;
2315 /* Scan the addresses in the header, enabling group syntax. Note that we
2316 have to reset this after the header has been scanned. */
2318 parse_allow_group = TRUE;
2322 address_item *vaddr;
2324 while (isspace(*s) || *s == ',') s++;
2325 if (*s == 0) break; /* End of header */
2327 ss = parse_find_address_end(s, FALSE);
2329 /* The terminator is a comma or end of header, but there may be white
2330 space preceding it (including newline for the last address). Move back
2331 past any white space so we can check against any cached envelope sender
2332 address verifications. */
2334 while (isspace(ss[-1])) ss--;
2338 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2339 (int)(endname - h->text), h->text, s);
2341 /* See if we have already verified this address as an envelope sender,
2342 and if so, use the previous answer. */
2344 vaddr = verify_checked_sender(s);
2346 if (vaddr != NULL && /* Previously checked */
2347 (callout <= 0 || /* No callout needed; OR */
2348 vaddr->special_action > 256)) /* Callout was done */
2350 new_ok = vaddr->special_action & 255;
2351 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2352 *ss = terminator; /* Restore shortened string */
2355 /* Otherwise we run the verification now. We must restore the shortened
2356 string before running the verification, so the headers are correct, in
2357 case there is any rewriting. */
2361 int start, end, domain;
2362 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2367 /* If we found an empty address, just carry on with the next one, but
2368 kill the message. */
2370 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2377 /* If verification failed because of a syntax error, fail this
2378 function, and ensure that the failing address gets added to the error
2381 if (address == NULL)
2384 while (ss > s && isspace(ss[-1])) ss--;
2385 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2386 "scanning for sender: %s in \"%.*s\"",
2387 endname - h->text, h->text, *log_msgptr, ss - s, s);
2393 /* Else go ahead with the sender verification. But it isn't *the*
2394 sender of the message, so set vopt_fake_sender to stop sender_address
2395 being replaced after rewriting or qualification. */
2399 vaddr = deliver_make_addr(address, FALSE);
2400 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2401 callout, callout_overall, callout_connect, se_mailfrom,
2406 /* We now have the result, either newly found, or cached. If we are
2407 giving out error details, set a specific user error. This means that the
2408 last of these will be returned to the user if all three fail. We do not
2409 set a log message - the generic one below will be used. */
2413 *verrno = vaddr->basic_errno;
2414 if (smtp_return_error_details)
2416 *user_msgptr = string_sprintf("Rejected after DATA: "
2417 "could not verify \"%.*s\" header address\n%s: %s",
2418 endname - h->text, h->text, vaddr->address, vaddr->message);
2422 /* Success or defer */
2431 if (new_ok == DEFER) yield = DEFER;
2433 /* Move on to any more addresses in the header */
2436 } /* Next address */
2438 parse_allow_group = FALSE;
2439 parse_found_group = FALSE;
2440 } /* Next header, unless done */
2441 } /* Next header type unless done */
2443 if (yield == FAIL && *log_msgptr == NULL)
2444 *log_msgptr = US"there is no valid sender in any header line";
2446 if (yield == DEFER && *log_msgptr == NULL)
2447 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2455 /*************************************************
2456 * Get RFC 1413 identification *
2457 *************************************************/
2459 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2460 the timeout is set to zero, then the query is not done. There may also be lists
2461 of hosts and nets which are exempt. To guard against malefactors sending
2462 non-printing characters which could, for example, disrupt a message's headers,
2463 make sure the string consists of printing characters only.
2466 port the port to connect to; usually this is IDENT_PORT (113), but when
2467 running in the test harness with -bh a different value is used.
2471 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2475 verify_get_ident(int port)
2477 int sock, host_af, qlen;
2478 int received_sender_port, received_interface_port, n;
2480 uschar buffer[2048];
2482 /* Default is no ident. Check whether we want to do an ident check for this
2485 sender_ident = NULL;
2486 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2489 DEBUG(D_ident) debug_printf("doing ident callback\n");
2491 /* Set up a connection to the ident port of the remote host. Bind the local end
2492 to the incoming interface address. If the sender host address is an IPv6
2493 address, the incoming interface address will also be IPv6. */
2495 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2496 sock = ip_socket(SOCK_STREAM, host_af);
2497 if (sock < 0) return;
2499 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2501 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2506 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2509 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2511 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2512 sender_host_address);
2516 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2517 sender_host_address, strerror(errno));
2522 /* Construct and send the query. */
2524 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2525 qlen = Ustrlen(buffer);
2526 if (send(sock, buffer, qlen, 0) < 0)
2528 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2532 /* Read a response line. We put it into the rest of the buffer, using several
2533 recv() calls if necessary. */
2541 int size = sizeof(buffer) - (p - buffer);
2543 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2544 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2545 if (count <= 0) goto END_OFF; /* Read error or EOF */
2547 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2548 generous, and accept a plain \n terminator as well. The only illegal
2551 for (pp = p; pp < p + count; pp++)
2553 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2556 if (pp[-1] == '\r') pp--;
2558 goto GOT_DATA; /* Break out of both loops */
2562 /* Reached the end of the data without finding \n. Let the loop continue to
2563 read some more, if there is room. */
2570 /* We have received a line of data. Check it carefully. It must start with the
2571 same two port numbers that we sent, followed by data as defined by the RFC. For
2574 12345 , 25 : USERID : UNIX :root
2576 However, the amount of white space may be different to what we sent. In the
2577 "osname" field there may be several sub-fields, comma separated. The data we
2578 actually want to save follows the third colon. Some systems put leading spaces
2579 in it - we discard those. */
2581 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2582 &received_interface_port, &n) != 2 ||
2583 received_sender_port != sender_host_port ||
2584 received_interface_port != interface_port)
2587 p = buffer + qlen + n;
2588 while(isspace(*p)) p++;
2589 if (*p++ != ':') goto END_OFF;
2590 while(isspace(*p)) p++;
2591 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2593 while(isspace(*p)) p++;
2594 if (*p++ != ':') goto END_OFF;
2595 while (*p != 0 && *p != ':') p++;
2596 if (*p++ == 0) goto END_OFF;
2597 while(isspace(*p)) p++;
2598 if (*p == 0) goto END_OFF;
2600 /* The rest of the line is the data we want. We turn it into printing
2601 characters when we save it, so that it cannot mess up the format of any logging
2602 or Received: lines into which it gets inserted. We keep a maximum of 127
2605 sender_ident = string_printing(string_copyn(p, 127));
2606 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2616 /*************************************************
2617 * Match host to a single host-list item *
2618 *************************************************/
2620 /* This function compares a host (name or address) against a single item
2621 from a host list. The host name gets looked up if it is needed and is not
2622 already known. The function is called from verify_check_this_host() via
2623 match_check_list(), which is why most of its arguments are in a single block.
2626 arg the argument block (see below)
2627 ss the host-list item
2628 valueptr where to pass back looked up data, or NULL
2629 error for error message when returning ERROR
2632 host_name (a) the host name, or
2633 (b) NULL, implying use sender_host_name and
2634 sender_host_aliases, looking them up if required, or
2635 (c) the empty string, meaning that only IP address matches
2637 host_address the host address
2638 host_ipv4 the IPv4 address taken from an IPv6 one
2642 DEFER lookup deferred
2643 ERROR (a) failed to find the host name or IP address, or
2644 (b) unknown lookup type specified, or
2645 (c) host name encountered when only IP addresses are
2650 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2652 check_host_block *cb = (check_host_block *)arg;
2655 BOOL iplookup = FALSE;
2656 BOOL isquery = FALSE;
2657 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2662 /* Optimize for the special case when the pattern is "*". */
2664 if (*ss == '*' && ss[1] == 0) return OK;
2666 /* If the pattern is empty, it matches only in the case when there is no host -
2667 this can occur in ACL checking for SMTP input using the -bs option. In this
2668 situation, the host address is the empty string. */
2670 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2671 if (*ss == 0) return FAIL;
2673 /* If the pattern is precisely "@" then match against the primary host name,
2674 provided that host name matching is permitted; if it's "@[]" match against the
2675 local host's IP addresses. */
2681 if (isiponly) return ERROR;
2682 ss = primary_hostname;
2684 else if (Ustrcmp(ss, "@[]") == 0)
2686 ip_address_item *ip;
2687 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2688 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2693 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2694 a (possibly masked) comparision with the current IP address. */
2696 if (string_is_ip_address(ss, &maskoffset) != 0)
2697 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2699 /* The pattern is not an IP address. A common error that people make is to omit
2700 one component of an IPv4 address, either by accident, or believing that, for
2701 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,
2702 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2703 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2704 ancient specification.) To aid in debugging these cases, we give a specific
2705 error if the pattern contains only digits and dots or contains a slash preceded
2706 only by digits and dots (a slash at the start indicates a file name and of
2707 course slashes may be present in lookups, but not preceded only by digits and
2710 for (t = ss; isdigit(*t) || *t == '.'; t++);
2711 if (*t == 0 || (*t == '/' && t != ss))
2713 *error = US"malformed IPv4 address or address mask";
2717 /* See if there is a semicolon in the pattern */
2719 semicolon = Ustrchr(ss, ';');
2721 /* If we are doing an IP address only match, then all lookups must be IP
2722 address lookups, even if there is no "net-". */
2726 iplookup = semicolon != NULL;
2729 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2730 a lookup on a masked IP network, in textual form. We obey this code even if we
2731 have already set iplookup, so as to skip over the "net-" prefix and to set the
2732 mask length. The net- stuff really only applies to single-key lookups where the
2733 key is implicit. For query-style lookups the key is specified in the query.
2734 From release 4.30, the use of net- for query style is no longer needed, but we
2735 retain it for backward compatibility. */
2737 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2740 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2741 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2742 iplookup = (*t++ == '-');
2746 /* Do the IP address lookup if that is indeed what we have */
2754 uschar *filename, *key, *result;
2757 /* Find the search type */
2759 search_type = search_findtype(t, semicolon - t);
2761 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2762 search_error_message);
2764 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2765 is no file name, and the "key" is just the query. For query-style with a file
2766 name, we have to fish the file off the start of the query. For a single-key
2767 lookup, the key is the current IP address, masked appropriately, and
2768 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2769 dot separators instead of colons, except when the lookup type is "iplsearch".
2772 if (mac_islookup(search_type, lookup_absfilequery))
2774 filename = semicolon + 1;
2776 while (*key != 0 && !isspace(*key)) key++;
2777 filename = string_copyn(filename, key - filename);
2778 while (isspace(*key)) key++;
2780 else if (mac_islookup(search_type, lookup_querystyle))
2783 key = semicolon + 1;
2785 else /* Single-key style */
2787 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2789 insize = host_aton(cb->host_address, incoming);
2790 host_mask(insize, incoming, mlen);
2791 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2793 filename = semicolon + 1;
2796 /* Now do the actual lookup; note that there is no search_close() because
2797 of the caching arrangements. */
2799 handle = search_open(filename, search_type, 0, NULL, NULL);
2800 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2801 search_error_message);
2802 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2803 if (valueptr != NULL) *valueptr = result;
2804 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2807 /* The pattern is not an IP address or network reference of any kind. That is,
2808 it is a host name pattern. If this is an IP only match, there's an error in the
2813 *error = US"cannot match host name in match_ip list";
2817 /* Check the characters of the pattern to see if they comprise only letters,
2818 digits, full stops, and hyphens (the constituents of domain names). Allow
2819 underscores, as they are all too commonly found. Sigh. Also, if
2820 allow_utf8_domains is set, allow top-bit characters. */
2822 for (t = ss; *t != 0; t++)
2823 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2824 (!allow_utf8_domains || *t < 128)) break;
2826 /* If the pattern is a complete domain name, with no fancy characters, look up
2827 its IP address and match against that. Note that a multi-homed host will add
2828 items to the chain. */
2839 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2840 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2843 for (hh = &h; hh != NULL; hh = hh->next)
2845 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2849 if (rc == HOST_FIND_AGAIN) return DEFER;
2850 *error = string_sprintf("failed to find IP address for %s", ss);
2854 /* Almost all subsequent comparisons require the host name, and can be done
2855 using the general string matching function. When this function is called for
2856 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2857 must use sender_host_name and its aliases, looking them up if necessary. */
2859 if (cb->host_name != NULL) /* Explicit host name given */
2860 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2863 /* Host name not given; in principle we need the sender host name and its
2864 aliases. However, for query-style lookups, we do not need the name if the
2865 query does not contain $sender_host_name. From release 4.23, a reference to
2866 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2869 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2872 int partial, affixlen, starflags, id;
2875 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2878 if (id < 0) /* Unknown lookup type */
2880 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2881 search_error_message, ss);
2884 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2889 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2892 case DEFER: return DEFER;
2893 default: return FAIL;
2897 /* Not a query-style lookup; must ensure the host name is present, and then we
2898 do a check on the name and all its aliases. */
2900 if (sender_host_name == NULL)
2902 HDEBUG(D_host_lookup)
2903 debug_printf("sender host name required, to match against %s\n", ss);
2904 if (host_lookup_failed || host_name_lookup() != OK)
2906 *error = string_sprintf("failed to find host name for %s",
2907 sender_host_address);;
2910 host_build_sender_fullhost();
2913 /* Match on the sender host name, using the general matching function */
2915 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2919 case DEFER: return DEFER;
2922 /* If there are aliases, try matching on them. */
2924 aliases = sender_host_aliases;
2925 while (*aliases != NULL)
2927 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2930 case DEFER: return DEFER;
2939 /*************************************************
2940 * Check a specific host matches a host list *
2941 *************************************************/
2943 /* This function is passed a host list containing items in a number of
2944 different formats and the identity of a host. Its job is to determine whether
2945 the given host is in the set of hosts defined by the list. The host name is
2946 passed as a pointer so that it can be looked up if needed and not already
2947 known. This is commonly the case when called from verify_check_host() to check
2948 an incoming connection. When called from elsewhere the host name should usually
2951 This function is now just a front end to match_check_list(), which runs common
2952 code for scanning a list. We pass it the check_host() function to perform a
2956 listptr pointer to the host list
2957 cache_bits pointer to cache for named lists, or NULL
2958 host_name the host name or NULL, implying use sender_host_name and
2959 sender_host_aliases, looking them up if required
2960 host_address the IP address
2961 valueptr if not NULL, data from a lookup is passed back here
2963 Returns: OK if the host is in the defined set
2964 FAIL if the host is not in the defined set,
2965 DEFER if a data lookup deferred (not a host lookup)
2967 If the host name was needed in order to make a comparison, and could not be
2968 determined from the IP address, the result is FAIL unless the item
2969 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2972 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2973 uschar *host_name, uschar *host_address, uschar **valueptr)
2976 unsigned int *local_cache_bits = cache_bits;
2977 uschar *save_host_address = deliver_host_address;
2978 check_host_block cb;
2979 cb.host_name = host_name;
2980 cb.host_address = host_address;
2982 if (valueptr != NULL) *valueptr = NULL;
2984 /* If the host address starts off ::ffff: it is an IPv6 address in
2985 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2988 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2989 host_address + 7 : host_address;
2991 /* During the running of the check, put the IP address into $host_address. In
2992 the case of calls from the smtp transport, it will already be there. However,
2993 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2994 the safe side, any existing setting is preserved, though as I write this
2995 (November 2004) I can't see any cases where it is actually needed. */
2997 deliver_host_address = host_address;
2998 rc = match_check_list(
2999 listptr, /* the list */
3000 0, /* separator character */
3001 &hostlist_anchor, /* anchor pointer */
3002 &local_cache_bits, /* cache pointer */
3003 check_host, /* function for testing */
3004 &cb, /* argument for function */
3005 MCL_HOST, /* type of check */
3006 (host_address == sender_host_address)?
3007 US"host" : host_address, /* text for debugging */
3008 valueptr); /* where to pass back data */
3009 deliver_host_address = save_host_address;
3016 /*************************************************
3017 * Check the remote host matches a list *
3018 *************************************************/
3020 /* This is a front end to verify_check_this_host(), created because checking
3021 the remote host is a common occurrence. With luck, a good compiler will spot
3022 the tail recursion and optimize it. If there's no host address, this is
3023 command-line SMTP input - check against an empty string for the address.
3026 listptr pointer to the host list
3028 Returns: the yield of verify_check_this_host(),
3029 i.e. OK, FAIL, or DEFER
3033 verify_check_host(uschar **listptr)
3035 return verify_check_this_host(listptr, sender_host_cache, NULL,
3036 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3043 /*************************************************
3044 * Invert an IP address *
3045 *************************************************/
3047 /* Originally just used for DNS xBL lists, now also used for the
3048 reverse_ip expansion operator.
3051 buffer where to put the answer
3052 address the address to invert
3056 invert_address(uschar *buffer, uschar *address)
3059 uschar *bptr = buffer;
3061 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3062 to the IPv4 part only. */
3064 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3066 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3069 if (host_aton(address, bin) == 1)
3073 for (i = 0; i < 4; i++)
3075 sprintf(CS bptr, "%d.", x & 255);
3076 while (*bptr) bptr++;
3081 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3082 in any DNS black lists, and the format in which they will be looked up is
3083 unknown. This is just a guess. */
3089 for (j = 3; j >= 0; j--)
3092 for (i = 0; i < 8; i++)
3094 sprintf(CS bptr, "%x.", x & 15);
3095 while (*bptr) bptr++;
3102 /* Remove trailing period -- this is needed so that both arbitrary
3103 dnsbl keydomains and inverted addresses may be combined with the
3104 same format string, "%s.%s" */
3111 /*************************************************
3112 * Perform a single dnsbl lookup *
3113 *************************************************/
3115 /* This function is called from verify_check_dnsbl() below. It is also called
3116 recursively from within itself when domain and domain_txt are different
3117 pointers, in order to get the TXT record from the alternate domain.
3120 domain the outer dnsbl domain
3121 domain_txt alternate domain to lookup TXT record on success; when the
3122 same domain is to be used, domain_txt == domain (that is,
3123 the pointers must be identical, not just the text)
3124 keydomain the current keydomain (for debug message)
3125 prepend subdomain to lookup (like keydomain, but
3126 reversed if IP address)
3127 iplist the list of matching IP addresses, or NULL for "any"
3128 bitmask true if bitmask matching is wanted
3129 match_type condition for 'succeed' result
3130 0 => Any RR in iplist (=)
3131 1 => No RR in iplist (!=)
3132 2 => All RRs in iplist (==)
3133 3 => Some RRs not in iplist (!==)
3134 the two bits are defined as MT_NOT and MT_ALL
3135 defer_return what to return for a defer
3137 Returns: OK if lookup succeeded
3142 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3143 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3149 dnsbl_cache_block *cb;
3150 int old_pool = store_pool;
3151 uschar query[256]; /* DNS domain max length */
3153 /* Construct the specific query domainname */
3155 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3157 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3158 "(ignored): %s...", query);
3162 /* Look for this query in the cache. */
3164 t = tree_search(dnsbl_cache, query);
3166 /* If not cached from a previous lookup, we must do a DNS lookup, and
3167 cache the result in permanent memory. */
3171 store_pool = POOL_PERM;
3173 /* Set up a tree entry to cache the lookup */
3175 t = store_get(sizeof(tree_node) + Ustrlen(query));
3176 Ustrcpy(t->name, query);
3177 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3178 (void)tree_insertnode(&dnsbl_cache, t);
3180 /* Do the DNS loopup . */
3182 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3183 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3184 cb->text_set = FALSE;
3188 /* If the lookup succeeded, cache the RHS address. The code allows for
3189 more than one address - this was for complete generality and the possible
3190 use of A6 records. However, A6 records have been reduced to experimental
3191 status (August 2001) and may die out. So they may never get used at all,
3192 let alone in dnsbl records. However, leave the code here, just in case.
3194 Quite apart from one A6 RR generating multiple addresses, there are DNS
3195 lists that return more than one A record, so we must handle multiple
3196 addresses generated in that way as well. */
3198 if (cb->rc == DNS_SUCCEED)
3201 dns_address **addrp = &(cb->rhs);
3202 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3204 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3206 if (rr->type == T_A)
3208 dns_address *da = dns_address_from_rr(&dnsa, rr);
3212 while (da->next != NULL) da = da->next;
3213 addrp = &(da->next);
3218 /* If we didn't find any A records, change the return code. This can
3219 happen when there is a CNAME record but there are no A records for what
3222 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3225 store_pool = old_pool;
3228 /* Previous lookup was cached */
3232 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3236 /* We now have the result of the DNS lookup, either newly done, or cached
3237 from a previous call. If the lookup succeeded, check against the address
3238 list if there is one. This may be a positive equality list (introduced by
3239 "="), a negative equality list (introduced by "!="), a positive bitmask
3240 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3242 if (cb->rc == DNS_SUCCEED)
3244 dns_address *da = NULL;
3245 uschar *addlist = cb->rhs->address;
3247 /* For A and AAAA records, there may be multiple addresses from multiple
3248 records. For A6 records (currently not expected to be used) there may be
3249 multiple addresses from a single record. */
3251 for (da = cb->rhs->next; da != NULL; da = da->next)
3252 addlist = string_sprintf("%s, %s", addlist, da->address);
3254 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3257 /* Address list check; this can be either for equality, or via a bitmask.
3258 In the latter case, all the bits must match. */
3262 for (da = cb->rhs; da != NULL; da = da->next)
3266 uschar *ptr = iplist;
3269 /* Handle exact matching */
3273 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3275 if (Ustrcmp(CS da->address, ip) == 0) break;
3279 /* Handle bitmask matching */
3286 /* At present, all known DNS blocking lists use A records, with
3287 IPv4 addresses on the RHS encoding the information they return. I
3288 wonder if this will linger on as the last vestige of IPv4 when IPv6
3289 is ubiquitous? Anyway, for now we use paranoia code to completely
3290 ignore IPv6 addresses. The default mask is 0, which always matches.
3291 We change this only for IPv4 addresses in the list. */
3293 if (host_aton(da->address, address) == 1) mask = address[0];
3295 /* Scan the returned addresses, skipping any that are IPv6 */
3297 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3299 if (host_aton(ip, address) != 1) continue;
3300 if ((address[0] & mask) == address[0]) break;
3306 (a) An IP address in an any ('=') list matched, or
3307 (b) No IP address in an all ('==') list matched
3309 then we're done searching. */
3311 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3314 /* If da == NULL, either
3316 (a) No IP address in an any ('=') list matched, or
3317 (b) An IP address in an all ('==') list didn't match
3319 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3322 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3330 res = US"was no match";
3333 res = US"was an exclude match";
3336 res = US"was an IP address that did not match";
3339 res = US"were no IP addresses that did not match";
3342 debug_printf("=> but we are not accepting this block class because\n");
3343 debug_printf("=> there %s for %s%c%s\n",
3345 ((match_type & MT_ALL) == 0)? "" : "=",
3346 bitmask? '&' : '=', iplist);
3352 /* Either there was no IP list, or the record matched, implying that the
3353 domain is on the list. We now want to find a corresponding TXT record. If an
3354 alternate domain is specified for the TXT record, call this function
3355 recursively to look that up; this has the side effect of re-checking that
3356 there is indeed an A record at the alternate domain. */
3358 if (domain_txt != domain)
3359 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3360 FALSE, match_type, defer_return);
3362 /* If there is no alternate domain, look up a TXT record in the main domain
3363 if it has not previously been cached. */
3367 cb->text_set = TRUE;
3368 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3371 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3373 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3374 if (rr->type == T_TXT) break;
3377 int len = (rr->data)[0];
3378 if (len > 511) len = 127;
3379 store_pool = POOL_PERM;
3380 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3381 store_pool = old_pool;
3386 dnslist_value = addlist;
3387 dnslist_text = cb->text;
3391 /* There was a problem with the DNS lookup */
3393 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3395 log_write(L_dnslist_defer, LOG_MAIN,
3396 "DNS list lookup defer (probably timeout) for %s: %s", query,
3397 (defer_return == OK)? US"assumed in list" :
3398 (defer_return == FAIL)? US"assumed not in list" :
3399 US"returned DEFER");
3400 return defer_return;
3403 /* No entry was found in the DNS; continue for next domain */
3407 debug_printf("DNS lookup for %s failed\n", query);
3408 debug_printf("=> that means %s is not listed at %s\n",
3418 /*************************************************
3419 * Check host against DNS black lists *
3420 *************************************************/
3422 /* This function runs checks against a list of DNS black lists, until one
3423 matches. Each item on the list can be of the form
3425 domain=ip-address/key
3427 The domain is the right-most domain that is used for the query, for example,
3428 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3429 if the DNS lookup returns a matching IP address. Several addresses may be
3430 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3432 If no key is given, what is looked up in the domain is the inverted IP address
3433 of the current client host. If a key is given, it is used to construct the
3434 domain for the lookup. For example:
3436 dsn.rfc-ignorant.org/$sender_address_domain
3438 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3439 then we check for a TXT record for an error message, and if found, save its
3440 value in $dnslist_text. We also cache everything in a tree, to optimize
3443 The TXT record is normally looked up in the same domain as the A record, but
3444 when many lists are combined in a single DNS domain, this will not be a very
3445 specific message. It is possible to specify a different domain for looking up
3446 TXT records; this is given before the main domain, comma-separated. For
3449 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3450 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3452 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3454 Note: an address for testing RBL is 192.203.178.39
3455 Note: an address for testing DUL is 192.203.178.4
3456 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3459 listptr the domain/address/data list
3461 Returns: OK successful lookup (i.e. the address is on the list), or
3462 lookup deferred after +include_unknown
3463 FAIL name not found, or no data found for the given type, or
3464 lookup deferred after +exclude_unknown (default)
3465 DEFER lookup failure, if +defer_unknown was set
3469 verify_check_dnsbl(uschar **listptr)
3472 int defer_return = FAIL;
3473 uschar *list = *listptr;
3476 uschar buffer[1024];
3477 uschar revadd[128]; /* Long enough for IPv6 address */
3479 /* Indicate that the inverted IP address is not yet set up */
3483 /* In case this is the first time the DNS resolver is being used. */
3485 dns_init(FALSE, FALSE);
3487 /* Loop through all the domains supplied, until something matches */
3489 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3492 BOOL bitmask = FALSE;
3499 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3501 /* Deal with special values that change the behaviour on defer */
3503 if (domain[0] == '+')
3505 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3506 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3507 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3509 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3514 /* See if there's explicit data to be looked up */
3516 key = Ustrchr(domain, '/');
3517 if (key != NULL) *key++ = 0;
3519 /* See if there's a list of addresses supplied after the domain name. This is
3520 introduced by an = or a & character; if preceded by = we require all matches
3521 and if preceded by ! we invert the result. */
3523 iplist = Ustrchr(domain, '=');
3527 iplist = Ustrchr(domain, '&');
3530 if (iplist != NULL) /* Found either = or & */
3532 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3534 match_type |= MT_NOT;
3538 *iplist++ = 0; /* Terminate domain, move on */
3540 /* If we found = (bitmask == FALSE), check for == or =& */
3542 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3544 bitmask = *iplist++ == '&';
3545 match_type |= MT_ALL;
3549 /* If there is a comma in the domain, it indicates that a second domain for
3550 looking up TXT records is provided, before the main domain. Otherwise we must
3551 set domain_txt == domain. */
3553 domain_txt = domain;
3554 comma = Ustrchr(domain, ',');
3561 /* Check that what we have left is a sensible domain name. There is no reason
3562 why these domains should in fact use the same syntax as hosts and email
3563 domains, but in practice they seem to. However, there is little point in
3564 actually causing an error here, because that would no doubt hold up incoming
3565 mail. Instead, I'll just log it. */
3567 for (s = domain; *s != 0; s++)
3569 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3571 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3572 "strange characters - is this right?", domain);
3577 /* Check the alternate domain if present */
3579 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3581 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3583 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3584 "strange characters - is this right?", domain_txt);
3589 /* If there is no key string, construct the query by adding the domain name
3590 onto the inverted host address, and perform a single DNS lookup. */
3594 if (sender_host_address == NULL) return FAIL; /* can never match */
3595 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3596 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3597 iplist, bitmask, match_type, defer_return);
3600 dnslist_domain = string_copy(domain_txt);
3601 dnslist_matched = string_copy(sender_host_address);
3602 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3603 sender_host_address, dnslist_domain);
3605 if (rc != FAIL) return rc; /* OK or DEFER */
3608 /* If there is a key string, it can be a list of domains or IP addresses to
3609 be concatenated with the main domain. */
3616 uschar keybuffer[256];
3617 uschar keyrevadd[128];
3619 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3620 sizeof(keybuffer))) != NULL)
3622 uschar *prepend = keydomain;
3624 if (string_is_ip_address(keydomain, NULL) != 0)
3626 invert_address(keyrevadd, keydomain);
3627 prepend = keyrevadd;
3630 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3631 bitmask, match_type, defer_return);
3635 dnslist_domain = string_copy(domain_txt);
3636 dnslist_matched = string_copy(keydomain);
3637 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3638 keydomain, dnslist_domain);
3642 /* If the lookup deferred, remember this fact. We keep trying the rest
3643 of the list to see if we get a useful result, and if we don't, we return
3644 DEFER at the end. */
3646 if (rc == DEFER) defer = TRUE;
3647 } /* continue with next keystring domain/address */
3649 if (defer) return DEFER;
3651 } /* continue with next dnsdb outer domain */
3656 /* End of verify.c */