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;
725 /* Send the MAIL command */
728 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
729 from_address) >= 0 &&
730 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
733 /* If the host does not accept MAIL FROM:<>, arrange to cache this
734 information, but again, don't record anything for an I/O error or a defer. Do
735 not cache rejections of MAIL when a non-empty sender has been used, because
736 that blocks the whole domain for all senders. */
740 *failure_ptr = US"mail"; /* At or before MAIL */
741 if (errno == 0 && responsebuffer[0] == '5')
743 setflag(addr, af_verify_nsfail);
744 if (from_address[0] == 0)
745 new_domain_record.result = ccache_reject_mfnull;
749 /* Otherwise, proceed to check a "random" address (if required), then the
750 given address, and the postmaster address (if required). Between each check,
751 issue RSET, because some servers accept only one recipient after MAIL
754 Before doing this, set the result in the domain cache record to "accept",
755 unless its previous value was ccache_reject_mfnull. In that case, the domain
756 rejects MAIL FROM:<> and we want to continue to remember that. When that is
757 the case, we have got here only in the case of a recipient verification with
758 a non-null sender. */
762 new_domain_record.result =
763 (old_domain_cache_result == ccache_reject_mfnull)?
764 ccache_reject_mfnull: ccache_accept;
766 /* Do the random local part check first */
768 if (random_local_part != NULL)
770 uschar randombuffer[1024];
772 smtp_write_command(&outblock, FALSE,
773 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
774 addr->domain) >= 0 &&
775 smtp_read_response(&inblock, randombuffer,
776 sizeof(randombuffer), '2', callout);
778 /* Remember when we last did a random test */
780 new_domain_record.random_stamp = time(NULL);
782 /* If accepted, we aren't going to do any further tests below. */
786 new_domain_record.random_result = ccache_accept;
789 /* Otherwise, cache a real negative response, and get back to the right
790 state to send RCPT. Unless there's some problem such as a dropped
791 connection, we expect to succeed, because the commands succeeded above. */
795 if (randombuffer[0] == '5')
796 new_domain_record.random_result = ccache_reject;
799 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
800 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
803 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
804 from_address) >= 0 &&
805 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
808 else done = FALSE; /* Some timeout/connection problem */
811 /* If the host is accepting all local parts, as determined by the "random"
812 check, we don't need to waste time doing any further checking. */
814 if (new_domain_record.random_result != ccache_accept && done)
816 /* Get the rcpt_include_affixes flag from the transport if there is one,
817 but assume FALSE if there is not. */
820 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
821 transport_rcpt_address(addr,
822 (addr->transport == NULL)? FALSE :
823 addr->transport->rcpt_include_affixes)) >= 0 &&
824 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
828 new_address_record.result = ccache_accept;
829 else if (errno == 0 && responsebuffer[0] == '5')
831 *failure_ptr = US"recipient";
832 new_address_record.result = ccache_reject;
835 /* Do postmaster check if requested; if a full check is required, we
836 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
838 if (done && pm_mailfrom != NULL)
840 /*XXX not suitable for cutthrough - sequencing problems */
841 cutthrough_delivery= FALSE;
842 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
845 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
846 smtp_read_response(&inblock, responsebuffer,
847 sizeof(responsebuffer), '2', callout) &&
849 smtp_write_command(&outblock, FALSE,
850 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
851 smtp_read_response(&inblock, responsebuffer,
852 sizeof(responsebuffer), '2', callout) &&
854 /* First try using the current domain */
857 smtp_write_command(&outblock, FALSE,
858 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
859 smtp_read_response(&inblock, responsebuffer,
860 sizeof(responsebuffer), '2', callout)
865 /* If that doesn't work, and a full check is requested,
866 try without the domain. */
869 (options & vopt_callout_fullpm) != 0 &&
870 smtp_write_command(&outblock, FALSE,
871 "RCPT TO:<postmaster>\r\n") >= 0 &&
872 smtp_read_response(&inblock, responsebuffer,
873 sizeof(responsebuffer), '2', callout)
876 /* Sort out the cache record */
878 new_domain_record.postmaster_stamp = time(NULL);
881 new_domain_record.postmaster_result = ccache_accept;
882 else if (errno == 0 && responsebuffer[0] == '5')
884 *failure_ptr = US"postmaster";
885 setflag(addr, af_verify_pmfail);
886 new_domain_record.postmaster_result = ccache_reject;
889 } /* Random not accepted */
890 } /* MAIL FROM: accepted */
892 /* For any failure of the main check, other than a negative response, we just
893 close the connection and carry on. We can identify a negative response by the
894 fact that errno is zero. For I/O errors it will be non-zero
896 Set up different error texts for logging and for sending back to the caller
897 as an SMTP response. Log in all cases, using a one-line format. For sender
898 callouts, give a full response to the caller, but for recipient callouts,
899 don't give the IP address because this may be an internal host whose identity
900 is not to be widely broadcast. */
904 if (errno == ETIMEDOUT)
906 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
911 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
914 string_sprintf("response to \"%s\" from %s [%s] was: %s",
915 big_buffer, host->name, host->address,
916 string_printing(responsebuffer));
918 addr->user_message = is_recipient?
919 string_sprintf("Callout verification failed:\n%s", responsebuffer)
921 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
922 host->address, big_buffer, responsebuffer);
924 /* Hard rejection ends the process */
926 if (responsebuffer[0] == '5') /* Address rejected */
934 /* End the SMTP conversation and close the connection. */
936 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
937 and we have no cutthrough conn so far
938 here is where we want to leave the conn open */
939 if ( cutthrough_delivery
942 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
943 && !random_local_part
948 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
949 cutthrough_addr = *addr; /* Save the address_item for later logging */
950 cutthrough_addr.host_used = store_get(sizeof(host_item));
951 cutthrough_addr.host_used->name = host->name;
952 cutthrough_addr.host_used->address = host->address;
953 cutthrough_addr.host_used->port = port;
955 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
956 ctblock.buffer = ctbuffer;
957 ctblock.buffersize = sizeof(ctbuffer);
958 ctblock.ptr = ctbuffer;
959 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
960 ctblock.sock = cutthrough_fd;
964 /* Ensure no cutthrough on multiple address verifies */
965 if (options & vopt_callout_recipsender)
966 cancel_cutthrough_connection("multiple verify calls");
967 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
970 tls_close(FALSE, TRUE);
972 (void)close(inblock.sock);
975 } /* Loop through all hosts, while !done */
978 /* If we get here with done == TRUE, a successful callout happened, and yield
979 will be set OK or FAIL according to the response to the RCPT command.
980 Otherwise, we looped through the hosts but couldn't complete the business.
981 However, there may be domain-specific information to cache in both cases.
983 The value of the result field in the new_domain record is ccache_unknown if
984 there was an error before or with MAIL FROM:, and errno was not zero,
985 implying some kind of I/O error. We don't want to write the cache in that case.
986 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
988 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
990 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
993 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
997 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
998 (int)sizeof(dbdata_callout_cache));
999 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1000 " result=%d postmaster=%d random=%d\n",
1001 new_domain_record.result,
1002 new_domain_record.postmaster_result,
1003 new_domain_record.random_result);
1007 /* If a definite result was obtained for the callout, cache it unless caching
1012 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1014 if (dbm_file == NULL)
1015 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1016 if (dbm_file == NULL)
1018 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1022 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1023 (int)sizeof(dbdata_callout_cache_address));
1024 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1025 (new_address_record.result == ccache_accept)? "positive" : "negative");
1030 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1031 temporary error. If there was only one host, and a response was received, leave
1032 it alone if supplying details. Otherwise, give a generic response. */
1036 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1037 is_recipient? "recipient" : "sender");
1040 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1042 addr->user_message = (!smtp_return_error_details)? dullmsg :
1043 string_sprintf("%s for <%s>.\n"
1044 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1045 "they may be permanently unreachable from this server. In the latter case,\n%s",
1046 dullmsg, addr->address,
1048 "the address will never be accepted."
1050 "you need to change the address or create an MX record for its domain\n"
1051 "if it is supposed to be generally accessible from the Internet.\n"
1052 "Talk to your mail administrator for details.");
1054 /* Force a specific error code */
1056 addr->basic_errno = ERRNO_CALLOUTDEFER;
1059 /* Come here from within the cache-reading code on fast-track exit. */
1062 if (dbm_file != NULL) dbfn_close(dbm_file);
1068 /* Called after recipient-acl to get a cutthrough connection open when
1069 one was requested and a recipient-verify wasn't subsequently done.
1072 open_cutthrough_connection( address_item * addr )
1076 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1077 /* We must use a copy of the address for verification, because it might
1081 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1082 (void) verify_address(&addr2, NULL,
1083 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1084 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1086 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1092 /* Send given number of bytes from the buffer */
1094 cutthrough_send(int n)
1096 if(cutthrough_fd < 0)
1101 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1103 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1106 transport_count += n;
1107 ctblock.ptr= ctblock.buffer;
1111 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1118 _cutthrough_puts(uschar * cp, int n)
1122 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1123 if(!cutthrough_send(ctblock.buffersize))
1126 *ctblock.ptr++ = *cp++;
1131 /* Buffered output of counted data block. Return boolean success */
1133 cutthrough_puts(uschar * cp, int n)
1135 if (cutthrough_fd < 0) return TRUE;
1136 if (_cutthrough_puts(cp, n)) return TRUE;
1137 cancel_cutthrough_connection("transmit failed");
1143 _cutthrough_flush_send( void )
1145 int n= ctblock.ptr-ctblock.buffer;
1148 if(!cutthrough_send(n))
1154 /* Send out any bufferred output. Return boolean success. */
1156 cutthrough_flush_send( void )
1158 if (_cutthrough_flush_send()) return TRUE;
1159 cancel_cutthrough_connection("transmit failed");
1165 cutthrough_put_nl( void )
1167 return cutthrough_puts(US"\r\n", 2);
1171 /* Get and check response from cutthrough target */
1173 cutthrough_response(char expect, uschar ** copy)
1175 smtp_inblock inblock;
1176 uschar inbuffer[4096];
1177 uschar responsebuffer[4096];
1179 inblock.buffer = inbuffer;
1180 inblock.buffersize = sizeof(inbuffer);
1181 inblock.ptr = inbuffer;
1182 inblock.ptrend = inbuffer;
1183 inblock.sock = cutthrough_fd;
1184 /* this relies on (inblock.sock == tls_out.active) */
1185 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1186 cancel_cutthrough_connection("target timeout on read");
1191 *copy= cp= string_copy(responsebuffer);
1192 /* Trim the trailing end of line */
1193 cp += Ustrlen(responsebuffer);
1194 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1195 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1198 return responsebuffer[0];
1202 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1204 cutthrough_predata( void )
1206 if(cutthrough_fd < 0)
1209 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1210 cutthrough_puts(US"DATA\r\n", 6);
1211 cutthrough_flush_send();
1213 /* Assume nothing buffered. If it was it gets ignored. */
1214 return cutthrough_response('3', NULL) == '3';
1218 /* Buffered send of headers. Return success boolean. */
1219 /* Expands newlines to wire format (CR,NL). */
1220 /* Also sends header-terminating blank line. */
1222 cutthrough_headers_send( void )
1225 uschar * cp1, * cp2;
1227 if(cutthrough_fd < 0)
1230 for(h= header_list; h != NULL; h= h->next)
1231 if(h->type != htype_old && h->text != NULL)
1232 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1233 if( !cutthrough_puts(cp1, cp2-cp1)
1234 || !cutthrough_put_nl())
1237 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1238 return cutthrough_put_nl();
1243 close_cutthrough_connection( const char * why )
1245 if(cutthrough_fd >= 0)
1247 /* We could be sending this after a bunch of data, but that is ok as
1248 the only way to cancel the transfer in dataphase is to drop the tcp
1249 conn before the final dot.
1251 ctblock.ptr = ctbuffer;
1252 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1253 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1254 _cutthrough_flush_send();
1255 /* No wait for response */
1258 tls_close(FALSE, TRUE);
1260 (void)close(cutthrough_fd);
1262 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1264 ctblock.ptr = ctbuffer;
1268 cancel_cutthrough_connection( const char * why )
1270 close_cutthrough_connection(why);
1271 cutthrough_delivery= FALSE;
1277 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1278 Log an OK response as a transmission.
1279 Close the connection.
1280 Return smtp response-class digit.
1283 cutthrough_finaldot( void )
1285 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1287 /* Assume data finshed with new-line */
1288 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1289 return cutthrough_addr.message;
1291 switch(cutthrough_response('2', &cutthrough_addr.message))
1294 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1295 close_cutthrough_connection("delivered");
1299 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1303 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1309 return cutthrough_addr.message;
1314 /*************************************************
1315 * Copy error to toplevel address *
1316 *************************************************/
1318 /* This function is used when a verify fails or defers, to ensure that the
1319 failure or defer information is in the original toplevel address. This applies
1320 when an address is redirected to a single new address, and the failure or
1321 deferral happens to the child address.
1324 vaddr the verify address item
1325 addr the final address item
1328 Returns: the value of YIELD
1332 copy_error(address_item *vaddr, address_item *addr, int yield)
1336 vaddr->message = addr->message;
1337 vaddr->user_message = addr->user_message;
1338 vaddr->basic_errno = addr->basic_errno;
1339 vaddr->more_errno = addr->more_errno;
1340 vaddr->p.address_data = addr->p.address_data;
1341 copyflag(vaddr, addr, af_pass_message);
1349 /**************************************************
1350 * printf that automatically handles TLS if needed *
1351 ***************************************************/
1353 /* This function is used by verify_address() as a substitute for all fprintf()
1354 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1355 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1356 that assumes that we always use the smtp_out FILE* when not using TLS or the
1357 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1358 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1362 f the candidate FILE* to write to
1363 format format string
1364 ... optional arguments
1370 static void PRINTF_FUNCTION(2,3)
1371 respond_printf(FILE *f, const char *format, ...)
1375 va_start(ap, format);
1376 if (smtp_out && (f == smtp_out))
1377 smtp_vprintf(format, ap);
1379 vfprintf(f, format, ap);
1385 /*************************************************
1386 * Verify an email address *
1387 *************************************************/
1389 /* This function is used both for verification (-bv and at other times) and
1390 address testing (-bt), which is indicated by address_test_mode being set.
1393 vaddr contains the address to verify; the next field in this block
1395 f if not NULL, write the result to this file
1396 options various option bits:
1397 vopt_fake_sender => this sender verify is not for the real
1398 sender (it was verify=sender=xxxx or an address from a
1399 header line) - rewriting must not change sender_address
1400 vopt_is_recipient => this is a recipient address, otherwise
1401 it's a sender address - this affects qualification and
1402 rewriting and messages from callouts
1403 vopt_qualify => qualify an unqualified address; else error
1404 vopt_expn => called from SMTP EXPN command
1405 vopt_success_on_redirect => when a new address is generated
1406 the verification instantly succeeds
1408 These ones are used by do_callout() -- the options variable
1411 vopt_callout_fullpm => if postmaster check, do full one
1412 vopt_callout_no_cache => don't use callout cache
1413 vopt_callout_random => do the "random" thing
1414 vopt_callout_recipsender => use real sender for recipient
1415 vopt_callout_recippmaster => use postmaster for recipient
1417 callout if > 0, specifies that callout is required, and gives timeout
1418 for individual commands
1419 callout_overall if > 0, gives overall timeout for the callout function;
1420 if < 0, a default is used (see do_callout())
1421 callout_connect the connection timeout for callouts
1422 se_mailfrom when callout is requested to verify a sender, use this
1423 in MAIL FROM; NULL => ""
1424 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1425 thing and use this as the sender address (may be "")
1427 routed if not NULL, set TRUE if routing succeeded, so we can
1428 distinguish between routing failed and callout failed
1430 Returns: OK address verified
1431 FAIL address failed to verify
1432 DEFER can't tell at present
1436 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1437 int callout_overall, int callout_connect, uschar *se_mailfrom,
1438 uschar *pm_mailfrom, BOOL *routed)
1441 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1442 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1443 BOOL expn = (options & vopt_expn) != 0;
1444 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1447 int verify_type = expn? v_expn :
1448 address_test_mode? v_none :
1449 is_recipient? v_recipient : v_sender;
1450 address_item *addr_list;
1451 address_item *addr_new = NULL;
1452 address_item *addr_remote = NULL;
1453 address_item *addr_local = NULL;
1454 address_item *addr_succeed = NULL;
1455 uschar **failure_ptr = is_recipient?
1456 &recipient_verify_failure : &sender_verify_failure;
1457 uschar *ko_prefix, *cr;
1458 uschar *address = vaddr->address;
1459 uschar *save_sender;
1460 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1462 /* Clear, just in case */
1464 *failure_ptr = NULL;
1466 /* Set up a prefix and suffix for error message which allow us to use the same
1467 output statements both in EXPN mode (where an SMTP response is needed) and when
1468 debugging with an output file. */
1472 ko_prefix = US"553 ";
1475 else ko_prefix = cr = US"";
1477 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1479 if (parse_find_at(address) == NULL)
1481 if ((options & vopt_qualify) == 0)
1484 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1485 ko_prefix, address, cr);
1486 *failure_ptr = US"qualify";
1489 address = rewrite_address_qualify(address, is_recipient);
1494 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1495 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1498 /* Rewrite and report on it. Clear the domain and local part caches - these
1499 may have been set by domains and local part tests during an ACL. */
1501 if (global_rewrite_rules != NULL)
1503 uschar *old = address;
1504 address = rewrite_address(address, is_recipient, FALSE,
1505 global_rewrite_rules, rewrite_existflags);
1508 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1509 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1510 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1514 /* If this is the real sender address, we must update sender_address at
1515 this point, because it may be referred to in the routers. */
1517 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1518 sender_address = address;
1520 /* If the address was rewritten to <> no verification can be done, and we have
1521 to return OK. This rewriting is permitted only for sender addresses; for other
1522 addresses, such rewriting fails. */
1524 if (address[0] == 0) return OK;
1526 /* Flip the legacy TLS-related variables over to the outbound set in case
1527 they're used in the context of a transport used by verification. Reset them
1528 at exit from this routine. */
1530 modify_variable(US"tls_bits", &tls_out.bits);
1531 modify_variable(US"tls_certificate_verified", &tls_out.certificate_verified);
1532 modify_variable(US"tls_cipher", &tls_out.cipher);
1533 modify_variable(US"tls_peerdn", &tls_out.peerdn);
1534 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1535 modify_variable(US"tls_sni", &tls_out.sni);
1538 /* Save a copy of the sender address for re-instating if we change it to <>
1539 while verifying a sender address (a nice bit of self-reference there). */
1541 save_sender = sender_address;
1543 /* Update the address structure with the possibly qualified and rewritten
1544 address. Set it up as the starting address on the chain of new addresses. */
1546 vaddr->address = address;
1549 /* We need a loop, because an address can generate new addresses. We must also
1550 cope with generated pipes and files at the top level. (See also the code and
1551 comment in deliver.c.) However, it is usually the case that the router for
1552 user's .forward files has its verify flag turned off.
1554 If an address generates more than one child, the loop is used only when
1555 full_info is set, and this can only be set locally. Remote enquiries just get
1556 information about the top level address, not anything that it generated. */
1558 while (addr_new != NULL)
1561 address_item *addr = addr_new;
1563 addr_new = addr->next;
1568 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1569 debug_printf("Considering %s\n", addr->address);
1572 /* Handle generated pipe, file or reply addresses. We don't get these
1573 when handling EXPN, as it does only one level of expansion. */
1575 if (testflag(addr, af_pfr))
1582 if (addr->address[0] == '>')
1584 allow = testflag(addr, af_allow_reply);
1585 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1589 allow = (addr->address[0] == '|')?
1590 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1591 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1594 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1595 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1596 "%s\n", addr->message);
1598 fprintf(f, "\n transport = %s\n", addr->transport->name);
1600 fprintf(f, " *** forbidden ***\n");
1605 /* Just in case some router parameter refers to it. */
1607 return_path = (addr->p.errors_address != NULL)?
1608 addr->p.errors_address : sender_address;
1610 /* Split the address into domain and local part, handling the %-hack if
1611 necessary, and then route it. While routing a sender address, set
1612 $sender_address to <> because that is what it will be if we were trying to
1613 send a bounce to the sender. */
1615 if (routed != NULL) *routed = FALSE;
1616 if ((rc = deliver_split_address(addr)) == OK)
1618 if (!is_recipient) sender_address = null_sender;
1619 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1620 &addr_succeed, verify_type);
1621 sender_address = save_sender; /* Put back the real sender */
1624 /* If routing an address succeeded, set the flag that remembers, for use when
1625 an ACL cached a sender verify (in case a callout fails). Then if routing set
1626 up a list of hosts or the transport has a host list, and the callout option
1627 is set, and we aren't in a host checking run, do the callout verification,
1628 and set another flag that notes that a callout happened. */
1632 if (routed != NULL) *routed = TRUE;
1635 host_item *host_list = addr->host_list;
1637 /* Make up some data for use in the case where there is no remote
1640 transport_feedback tf = {
1641 NULL, /* interface (=> any) */
1642 US"smtp", /* port */
1643 US"smtp", /* protocol */
1645 US"$smtp_active_hostname", /* helo_data */
1646 FALSE, /* hosts_override */
1647 FALSE, /* hosts_randomize */
1648 FALSE, /* gethostbyname */
1649 TRUE, /* qualify_single */
1650 FALSE /* search_parents */
1653 /* If verification yielded a remote transport, we want to use that
1654 transport's options, so as to mimic what would happen if we were really
1655 sending a message to this address. */
1657 if (addr->transport != NULL && !addr->transport->info->local)
1659 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1661 /* If the transport has hosts and the router does not, or if the
1662 transport is configured to override the router's hosts, we must build a
1663 host list of the transport's hosts, and find the IP addresses */
1665 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1668 uschar *save_deliver_domain = deliver_domain;
1669 uschar *save_deliver_localpart = deliver_localpart;
1671 host_list = NULL; /* Ignore the router's hosts */
1673 deliver_domain = addr->domain;
1674 deliver_localpart = addr->local_part;
1675 s = expand_string(tf.hosts);
1676 deliver_domain = save_deliver_domain;
1677 deliver_localpart = save_deliver_localpart;
1681 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1682 "\"%s\" in %s transport for callout: %s", tf.hosts,
1683 addr->transport->name, expand_string_message);
1688 uschar *canonical_name;
1689 host_item *host, *nexthost;
1690 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1692 /* Just ignore failures to find a host address. If we don't manage
1693 to find any addresses, the callout will defer. Note that more than
1694 one address may be found for a single host, which will result in
1695 additional host items being inserted into the chain. Hence we must
1696 save the next host first. */
1698 flags = HOST_FIND_BY_A;
1699 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1700 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1702 for (host = host_list; host != NULL; host = nexthost)
1704 nexthost = host->next;
1705 if (tf.gethostbyname ||
1706 string_is_ip_address(host->name, NULL) != 0)
1707 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1709 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1710 &canonical_name, NULL);
1716 /* Can only do a callout if we have at least one host! If the callout
1717 fails, it will have set ${sender,recipient}_verify_failure. */
1719 if (host_list != NULL)
1721 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1722 if (host_checking && !host_checking_callout)
1725 debug_printf("... callout omitted by default when host testing\n"
1726 "(Use -bhc if you want the callouts to happen.)\n");
1731 deliver_set_expansions(addr);
1733 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1734 callout_connect, options, se_mailfrom, pm_mailfrom);
1739 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1740 "transport provided a host list\n");
1745 /* Otherwise, any failure is a routing failure */
1747 else *failure_ptr = US"route";
1749 /* A router may return REROUTED if it has set up a child address as a result
1750 of a change of domain name (typically from widening). In this case we always
1751 want to continue to verify the new child. */
1753 if (rc == REROUTED) continue;
1755 /* Handle hard failures */
1762 address_item *p = addr->parent;
1764 respond_printf(f, "%s%s %s", ko_prefix,
1765 full_info? addr->address : address,
1766 address_test_mode? "is undeliverable" : "failed to verify");
1767 if (!expn && admin_user)
1769 if (addr->basic_errno > 0)
1770 respond_printf(f, ": %s", strerror(addr->basic_errno));
1771 if (addr->message != NULL)
1772 respond_printf(f, ": %s", addr->message);
1775 /* Show parents iff doing full info */
1777 if (full_info) while (p != NULL)
1779 respond_printf(f, "%s\n <-- %s", cr, p->address);
1782 respond_printf(f, "%s\n", cr);
1784 cancel_cutthrough_connection("routing hard fail");
1788 yield = copy_error(vaddr, addr, FAIL);
1796 else if (rc == DEFER)
1801 address_item *p = addr->parent;
1802 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1803 full_info? addr->address : address);
1804 if (!expn && admin_user)
1806 if (addr->basic_errno > 0)
1807 respond_printf(f, ": %s", strerror(addr->basic_errno));
1808 if (addr->message != NULL)
1809 respond_printf(f, ": %s", addr->message);
1810 else if (addr->basic_errno <= 0)
1811 respond_printf(f, ": unknown error");
1814 /* Show parents iff doing full info */
1816 if (full_info) while (p != NULL)
1818 respond_printf(f, "%s\n <-- %s", cr, p->address);
1821 respond_printf(f, "%s\n", cr);
1823 cancel_cutthrough_connection("routing soft fail");
1827 yield = copy_error(vaddr, addr, DEFER);
1830 else if (yield == OK) yield = DEFER;
1833 /* If we are handling EXPN, we do not want to continue to route beyond
1834 the top level (whose address is in "address"). */
1838 uschar *ok_prefix = US"250-";
1839 if (addr_new == NULL)
1841 if (addr_local == NULL && addr_remote == NULL)
1842 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1844 respond_printf(f, "250 <%s>\r\n", address);
1846 else while (addr_new != NULL)
1848 address_item *addr2 = addr_new;
1849 addr_new = addr2->next;
1850 if (addr_new == NULL) ok_prefix = US"250 ";
1851 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1857 /* Successful routing other than EXPN. */
1861 /* Handle successful routing when short info wanted. Otherwise continue for
1862 other (generated) addresses. Short info is the operational case. Full info
1863 can be requested only when debug_selector != 0 and a file is supplied.
1865 There is a conflict between the use of aliasing as an alternate email
1866 address, and as a sort of mailing list. If an alias turns the incoming
1867 address into just one address (e.g. J.Caesar->jc44) you may well want to
1868 carry on verifying the generated address to ensure it is valid when
1869 checking incoming mail. If aliasing generates multiple addresses, you
1870 probably don't want to do this. Exim therefore treats the generation of
1871 just a single new address as a special case, and continues on to verify the
1872 generated address. */
1874 if (!full_info && /* Stop if short info wanted AND */
1875 (((addr_new == NULL || /* No new address OR */
1876 addr_new->next != NULL || /* More than one new address OR */
1877 testflag(addr_new, af_pfr))) /* New address is pfr */
1879 (addr_new != NULL && /* At least one new address AND */
1880 success_on_redirect))) /* success_on_redirect is set */
1882 if (f != NULL) fprintf(f, "%s %s\n", address,
1883 address_test_mode? "is deliverable" : "verified");
1885 /* If we have carried on to verify a child address, we want the value
1886 of $address_data to be that of the child */
1888 vaddr->p.address_data = addr->p.address_data;
1893 } /* Loop for generated addresses */
1895 /* Display the full results of the successful routing, including any generated
1896 addresses. Control gets here only when full_info is set, which requires f not
1897 to be NULL, and this occurs only when a top-level verify is called with the
1898 debugging switch on.
1900 If there are no local and no remote addresses, and there were no pipes, files,
1901 or autoreplies, and there were no errors or deferments, the message is to be
1902 discarded, usually because of the use of :blackhole: in an alias file. */
1904 if (allok && addr_local == NULL && addr_remote == NULL)
1906 fprintf(f, "mail to %s is discarded\n", address);
1910 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1912 while (addr_list != NULL)
1914 address_item *addr = addr_list;
1915 address_item *p = addr->parent;
1916 addr_list = addr->next;
1918 fprintf(f, "%s", CS addr->address);
1919 #ifdef EXPERIMENTAL_SRS
1920 if(addr->p.srs_sender)
1921 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1924 /* If the address is a duplicate, show something about it. */
1926 if (!testflag(addr, af_pfr))
1929 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1930 fprintf(f, " [duplicate, would not be delivered]");
1931 else tree_add_duplicate(addr->unique, addr);
1934 /* Now show its parents */
1938 fprintf(f, "\n <-- %s", p->address);
1943 /* Show router, and transport */
1945 fprintf(f, "router = %s, ", addr->router->name);
1946 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1947 addr->transport->name);
1949 /* Show any hosts that are set up by a router unless the transport
1950 is going to override them; fiddle a bit to get a nice format. */
1952 if (addr->host_list != NULL && addr->transport != NULL &&
1953 !addr->transport->overrides_hosts)
1958 for (h = addr->host_list; h != NULL; h = h->next)
1960 int len = Ustrlen(h->name);
1961 if (len > maxlen) maxlen = len;
1962 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1963 if (len > maxaddlen) maxaddlen = len;
1965 for (h = addr->host_list; h != NULL; h = h->next)
1967 int len = Ustrlen(h->name);
1968 fprintf(f, " host %s ", h->name);
1969 while (len++ < maxlen) fprintf(f, " ");
1970 if (h->address != NULL)
1972 fprintf(f, "[%s] ", h->address);
1973 len = Ustrlen(h->address);
1975 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1977 fprintf(f, "[unknown] ");
1981 while (len++ < maxaddlen) fprintf(f," ");
1982 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1983 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1984 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1991 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
1992 the -bv or -bt case). */
1996 modify_variable(US"tls_bits", &tls_in.bits);
1997 modify_variable(US"tls_certificate_verified", &tls_in.certificate_verified);
1998 modify_variable(US"tls_cipher", &tls_in.cipher);
1999 modify_variable(US"tls_peerdn", &tls_in.peerdn);
2000 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
2001 modify_variable(US"tls_sni", &tls_in.sni);
2010 /*************************************************
2011 * Check headers for syntax errors *
2012 *************************************************/
2014 /* This function checks those header lines that contain addresses, and verifies
2015 that all the addresses therein are syntactially correct.
2018 msgptr where to put an error message
2025 verify_check_headers(uschar **msgptr)
2031 for (h = header_list; h != NULL && yield == OK; h = h->next)
2033 if (h->type != htype_from &&
2034 h->type != htype_reply_to &&
2035 h->type != htype_sender &&
2036 h->type != htype_to &&
2037 h->type != htype_cc &&
2038 h->type != htype_bcc)
2041 colon = Ustrchr(h->text, ':');
2043 while (isspace(*s)) s++;
2045 /* Loop for multiple addresses in the header, enabling group syntax. Note
2046 that we have to reset this after the header has been scanned. */
2048 parse_allow_group = TRUE;
2052 uschar *ss = parse_find_address_end(s, FALSE);
2053 uschar *recipient, *errmess;
2054 int terminator = *ss;
2055 int start, end, domain;
2057 /* Temporarily terminate the string at this point, and extract the
2058 operative address within, allowing group syntax. */
2061 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2064 /* Permit an unqualified address only if the message is local, or if the
2065 sending host is configured to be permitted to send them. */
2067 if (recipient != NULL && domain == 0)
2069 if (h->type == htype_from || h->type == htype_sender)
2071 if (!allow_unqualified_sender) recipient = NULL;
2075 if (!allow_unqualified_recipient) recipient = NULL;
2077 if (recipient == NULL) errmess = US"unqualified address not permitted";
2080 /* It's an error if no address could be extracted, except for the special
2081 case of an empty address. */
2083 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2085 uschar *verb = US"is";
2090 /* Arrange not to include any white space at the end in the
2091 error message or the header name. */
2093 while (t > s && isspace(t[-1])) t--;
2094 while (tt > h->text && isspace(tt[-1])) tt--;
2096 /* Add the address that failed to the error message, since in a
2097 header with very many addresses it is sometimes hard to spot
2098 which one is at fault. However, limit the amount of address to
2099 quote - cases have been seen where, for example, a missing double
2100 quote in a humungous To: header creates an "address" that is longer
2101 than string_sprintf can handle. */
2110 *msgptr = string_printing(
2111 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2112 errmess, tt - h->text, h->text, verb, len, s));
2115 break; /* Out of address loop */
2118 /* Advance to the next address */
2120 s = ss + (terminator? 1:0);
2121 while (isspace(*s)) s++;
2122 } /* Next address */
2124 parse_allow_group = FALSE;
2125 parse_found_group = FALSE;
2126 } /* Next header unless yield has been set FALSE */
2133 /*************************************************
2134 * Check for blind recipients *
2135 *************************************************/
2137 /* This function checks that every (envelope) recipient is mentioned in either
2138 the To: or Cc: header lines, thus detecting blind carbon copies.
2140 There are two ways of scanning that could be used: either scan the header lines
2141 and tick off the recipients, or scan the recipients and check the header lines.
2142 The original proposed patch did the former, but I have chosen to do the latter,
2143 because (a) it requires no memory and (b) will use fewer resources when there
2144 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2147 Returns: OK if there are no blind recipients
2148 FAIL if there is at least one blind recipient
2152 verify_check_notblind(void)
2155 for (i = 0; i < recipients_count; i++)
2159 uschar *address = recipients_list[i].address;
2161 for (h = header_list; !found && h != NULL; h = h->next)
2165 if (h->type != htype_to && h->type != htype_cc) continue;
2167 colon = Ustrchr(h->text, ':');
2169 while (isspace(*s)) s++;
2171 /* Loop for multiple addresses in the header, enabling group syntax. Note
2172 that we have to reset this after the header has been scanned. */
2174 parse_allow_group = TRUE;
2178 uschar *ss = parse_find_address_end(s, FALSE);
2179 uschar *recipient,*errmess;
2180 int terminator = *ss;
2181 int start, end, domain;
2183 /* Temporarily terminate the string at this point, and extract the
2184 operative address within, allowing group syntax. */
2187 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2190 /* If we found a valid recipient that has a domain, compare it with the
2191 envelope recipient. Local parts are compared case-sensitively, domains
2192 case-insensitively. By comparing from the start with length "domain", we
2193 include the "@" at the end, which ensures that we are comparing the whole
2194 local part of each address. */
2196 if (recipient != NULL && domain != 0)
2198 found = Ustrncmp(recipient, address, domain) == 0 &&
2199 strcmpic(recipient + domain, address + domain) == 0;
2203 /* Advance to the next address */
2205 s = ss + (terminator? 1:0);
2206 while (isspace(*s)) s++;
2207 } /* Next address */
2209 parse_allow_group = FALSE;
2210 parse_found_group = FALSE;
2211 } /* Next header (if found is false) */
2213 if (!found) return FAIL;
2214 } /* Next recipient */
2221 /*************************************************
2222 * Find if verified sender *
2223 *************************************************/
2225 /* Usually, just a single address is verified as the sender of the message.
2226 However, Exim can be made to verify other addresses as well (often related in
2227 some way), and this is useful in some environments. There may therefore be a
2228 chain of such addresses that have previously been tested. This function finds
2229 whether a given address is on the chain.
2231 Arguments: the address to be verified
2232 Returns: pointer to an address item, or NULL
2236 verify_checked_sender(uschar *sender)
2239 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2240 if (Ustrcmp(sender, addr->address) == 0) break;
2248 /*************************************************
2249 * Get valid header address *
2250 *************************************************/
2252 /* Scan the originator headers of the message, looking for an address that
2253 verifies successfully. RFC 822 says:
2255 o The "Sender" field mailbox should be sent notices of
2256 any problems in transport or delivery of the original
2257 messages. If there is no "Sender" field, then the
2258 "From" field mailbox should be used.
2260 o If the "Reply-To" field exists, then the reply should
2261 go to the addresses indicated in that field and not to
2262 the address(es) indicated in the "From" field.
2264 So we check a Sender field if there is one, else a Reply_to field, else a From
2265 field. As some strange messages may have more than one of these fields,
2266 especially if they are resent- fields, check all of them if there is more than
2270 user_msgptr points to where to put a user error message
2271 log_msgptr points to where to put a log error message
2272 callout timeout for callout check (passed to verify_address())
2273 callout_overall overall callout timeout (ditto)
2274 callout_connect connect callout timeout (ditto)
2275 se_mailfrom mailfrom for verify; NULL => ""
2276 pm_mailfrom sender for pm callout check (passed to verify_address())
2277 options callout options (passed to verify_address())
2278 verrno where to put the address basic_errno
2280 If log_msgptr is set to something without setting user_msgptr, the caller
2281 normally uses log_msgptr for both things.
2283 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2284 FAIL is given if no appropriate headers are found
2288 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2289 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2290 uschar *pm_mailfrom, int options, int *verrno)
2292 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2297 for (i = 0; i < 3 && !done; i++)
2300 for (h = header_list; h != NULL && !done; h = h->next)
2302 int terminator, new_ok;
2303 uschar *s, *ss, *endname;
2305 if (h->type != header_types[i]) continue;
2306 s = endname = Ustrchr(h->text, ':') + 1;
2308 /* Scan the addresses in the header, enabling group syntax. Note that we
2309 have to reset this after the header has been scanned. */
2311 parse_allow_group = TRUE;
2315 address_item *vaddr;
2317 while (isspace(*s) || *s == ',') s++;
2318 if (*s == 0) break; /* End of header */
2320 ss = parse_find_address_end(s, FALSE);
2322 /* The terminator is a comma or end of header, but there may be white
2323 space preceding it (including newline for the last address). Move back
2324 past any white space so we can check against any cached envelope sender
2325 address verifications. */
2327 while (isspace(ss[-1])) ss--;
2331 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2332 (int)(endname - h->text), h->text, s);
2334 /* See if we have already verified this address as an envelope sender,
2335 and if so, use the previous answer. */
2337 vaddr = verify_checked_sender(s);
2339 if (vaddr != NULL && /* Previously checked */
2340 (callout <= 0 || /* No callout needed; OR */
2341 vaddr->special_action > 256)) /* Callout was done */
2343 new_ok = vaddr->special_action & 255;
2344 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2345 *ss = terminator; /* Restore shortened string */
2348 /* Otherwise we run the verification now. We must restore the shortened
2349 string before running the verification, so the headers are correct, in
2350 case there is any rewriting. */
2354 int start, end, domain;
2355 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2360 /* If we found an empty address, just carry on with the next one, but
2361 kill the message. */
2363 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2370 /* If verification failed because of a syntax error, fail this
2371 function, and ensure that the failing address gets added to the error
2374 if (address == NULL)
2377 while (ss > s && isspace(ss[-1])) ss--;
2378 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2379 "scanning for sender: %s in \"%.*s\"",
2380 endname - h->text, h->text, *log_msgptr, ss - s, s);
2386 /* Else go ahead with the sender verification. But it isn't *the*
2387 sender of the message, so set vopt_fake_sender to stop sender_address
2388 being replaced after rewriting or qualification. */
2392 vaddr = deliver_make_addr(address, FALSE);
2393 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2394 callout, callout_overall, callout_connect, se_mailfrom,
2399 /* We now have the result, either newly found, or cached. If we are
2400 giving out error details, set a specific user error. This means that the
2401 last of these will be returned to the user if all three fail. We do not
2402 set a log message - the generic one below will be used. */
2406 *verrno = vaddr->basic_errno;
2407 if (smtp_return_error_details)
2409 *user_msgptr = string_sprintf("Rejected after DATA: "
2410 "could not verify \"%.*s\" header address\n%s: %s",
2411 endname - h->text, h->text, vaddr->address, vaddr->message);
2415 /* Success or defer */
2424 if (new_ok == DEFER) yield = DEFER;
2426 /* Move on to any more addresses in the header */
2429 } /* Next address */
2431 parse_allow_group = FALSE;
2432 parse_found_group = FALSE;
2433 } /* Next header, unless done */
2434 } /* Next header type unless done */
2436 if (yield == FAIL && *log_msgptr == NULL)
2437 *log_msgptr = US"there is no valid sender in any header line";
2439 if (yield == DEFER && *log_msgptr == NULL)
2440 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2448 /*************************************************
2449 * Get RFC 1413 identification *
2450 *************************************************/
2452 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2453 the timeout is set to zero, then the query is not done. There may also be lists
2454 of hosts and nets which are exempt. To guard against malefactors sending
2455 non-printing characters which could, for example, disrupt a message's headers,
2456 make sure the string consists of printing characters only.
2459 port the port to connect to; usually this is IDENT_PORT (113), but when
2460 running in the test harness with -bh a different value is used.
2464 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2468 verify_get_ident(int port)
2470 int sock, host_af, qlen;
2471 int received_sender_port, received_interface_port, n;
2473 uschar buffer[2048];
2475 /* Default is no ident. Check whether we want to do an ident check for this
2478 sender_ident = NULL;
2479 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2482 DEBUG(D_ident) debug_printf("doing ident callback\n");
2484 /* Set up a connection to the ident port of the remote host. Bind the local end
2485 to the incoming interface address. If the sender host address is an IPv6
2486 address, the incoming interface address will also be IPv6. */
2488 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2489 sock = ip_socket(SOCK_STREAM, host_af);
2490 if (sock < 0) return;
2492 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2494 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2499 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2502 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2504 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2505 sender_host_address);
2509 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2510 sender_host_address, strerror(errno));
2515 /* Construct and send the query. */
2517 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2518 qlen = Ustrlen(buffer);
2519 if (send(sock, buffer, qlen, 0) < 0)
2521 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2525 /* Read a response line. We put it into the rest of the buffer, using several
2526 recv() calls if necessary. */
2534 int size = sizeof(buffer) - (p - buffer);
2536 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2537 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2538 if (count <= 0) goto END_OFF; /* Read error or EOF */
2540 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2541 generous, and accept a plain \n terminator as well. The only illegal
2544 for (pp = p; pp < p + count; pp++)
2546 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2549 if (pp[-1] == '\r') pp--;
2551 goto GOT_DATA; /* Break out of both loops */
2555 /* Reached the end of the data without finding \n. Let the loop continue to
2556 read some more, if there is room. */
2563 /* We have received a line of data. Check it carefully. It must start with the
2564 same two port numbers that we sent, followed by data as defined by the RFC. For
2567 12345 , 25 : USERID : UNIX :root
2569 However, the amount of white space may be different to what we sent. In the
2570 "osname" field there may be several sub-fields, comma separated. The data we
2571 actually want to save follows the third colon. Some systems put leading spaces
2572 in it - we discard those. */
2574 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2575 &received_interface_port, &n) != 2 ||
2576 received_sender_port != sender_host_port ||
2577 received_interface_port != interface_port)
2580 p = buffer + qlen + n;
2581 while(isspace(*p)) p++;
2582 if (*p++ != ':') goto END_OFF;
2583 while(isspace(*p)) p++;
2584 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2586 while(isspace(*p)) p++;
2587 if (*p++ != ':') goto END_OFF;
2588 while (*p != 0 && *p != ':') p++;
2589 if (*p++ == 0) goto END_OFF;
2590 while(isspace(*p)) p++;
2591 if (*p == 0) goto END_OFF;
2593 /* The rest of the line is the data we want. We turn it into printing
2594 characters when we save it, so that it cannot mess up the format of any logging
2595 or Received: lines into which it gets inserted. We keep a maximum of 127
2598 sender_ident = string_printing(string_copyn(p, 127));
2599 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2609 /*************************************************
2610 * Match host to a single host-list item *
2611 *************************************************/
2613 /* This function compares a host (name or address) against a single item
2614 from a host list. The host name gets looked up if it is needed and is not
2615 already known. The function is called from verify_check_this_host() via
2616 match_check_list(), which is why most of its arguments are in a single block.
2619 arg the argument block (see below)
2620 ss the host-list item
2621 valueptr where to pass back looked up data, or NULL
2622 error for error message when returning ERROR
2625 host_name (a) the host name, or
2626 (b) NULL, implying use sender_host_name and
2627 sender_host_aliases, looking them up if required, or
2628 (c) the empty string, meaning that only IP address matches
2630 host_address the host address
2631 host_ipv4 the IPv4 address taken from an IPv6 one
2635 DEFER lookup deferred
2636 ERROR (a) failed to find the host name or IP address, or
2637 (b) unknown lookup type specified, or
2638 (c) host name encountered when only IP addresses are
2643 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2645 check_host_block *cb = (check_host_block *)arg;
2648 BOOL iplookup = FALSE;
2649 BOOL isquery = FALSE;
2650 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2655 /* Optimize for the special case when the pattern is "*". */
2657 if (*ss == '*' && ss[1] == 0) return OK;
2659 /* If the pattern is empty, it matches only in the case when there is no host -
2660 this can occur in ACL checking for SMTP input using the -bs option. In this
2661 situation, the host address is the empty string. */
2663 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2664 if (*ss == 0) return FAIL;
2666 /* If the pattern is precisely "@" then match against the primary host name,
2667 provided that host name matching is permitted; if it's "@[]" match against the
2668 local host's IP addresses. */
2674 if (isiponly) return ERROR;
2675 ss = primary_hostname;
2677 else if (Ustrcmp(ss, "@[]") == 0)
2679 ip_address_item *ip;
2680 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2681 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2686 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2687 a (possibly masked) comparision with the current IP address. */
2689 if (string_is_ip_address(ss, &maskoffset) != 0)
2690 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2692 /* The pattern is not an IP address. A common error that people make is to omit
2693 one component of an IPv4 address, either by accident, or believing that, for
2694 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,
2695 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2696 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2697 ancient specification.) To aid in debugging these cases, we give a specific
2698 error if the pattern contains only digits and dots or contains a slash preceded
2699 only by digits and dots (a slash at the start indicates a file name and of
2700 course slashes may be present in lookups, but not preceded only by digits and
2703 for (t = ss; isdigit(*t) || *t == '.'; t++);
2704 if (*t == 0 || (*t == '/' && t != ss))
2706 *error = US"malformed IPv4 address or address mask";
2710 /* See if there is a semicolon in the pattern */
2712 semicolon = Ustrchr(ss, ';');
2714 /* If we are doing an IP address only match, then all lookups must be IP
2715 address lookups, even if there is no "net-". */
2719 iplookup = semicolon != NULL;
2722 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2723 a lookup on a masked IP network, in textual form. We obey this code even if we
2724 have already set iplookup, so as to skip over the "net-" prefix and to set the
2725 mask length. The net- stuff really only applies to single-key lookups where the
2726 key is implicit. For query-style lookups the key is specified in the query.
2727 From release 4.30, the use of net- for query style is no longer needed, but we
2728 retain it for backward compatibility. */
2730 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2733 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2734 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2735 iplookup = (*t++ == '-');
2739 /* Do the IP address lookup if that is indeed what we have */
2747 uschar *filename, *key, *result;
2750 /* Find the search type */
2752 search_type = search_findtype(t, semicolon - t);
2754 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2755 search_error_message);
2757 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2758 is no file name, and the "key" is just the query. For query-style with a file
2759 name, we have to fish the file off the start of the query. For a single-key
2760 lookup, the key is the current IP address, masked appropriately, and
2761 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2762 dot separators instead of colons, except when the lookup type is "iplsearch".
2765 if (mac_islookup(search_type, lookup_absfilequery))
2767 filename = semicolon + 1;
2769 while (*key != 0 && !isspace(*key)) key++;
2770 filename = string_copyn(filename, key - filename);
2771 while (isspace(*key)) key++;
2773 else if (mac_islookup(search_type, lookup_querystyle))
2776 key = semicolon + 1;
2778 else /* Single-key style */
2780 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2782 insize = host_aton(cb->host_address, incoming);
2783 host_mask(insize, incoming, mlen);
2784 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2786 filename = semicolon + 1;
2789 /* Now do the actual lookup; note that there is no search_close() because
2790 of the caching arrangements. */
2792 handle = search_open(filename, search_type, 0, NULL, NULL);
2793 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2794 search_error_message);
2795 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2796 if (valueptr != NULL) *valueptr = result;
2797 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2800 /* The pattern is not an IP address or network reference of any kind. That is,
2801 it is a host name pattern. If this is an IP only match, there's an error in the
2806 *error = US"cannot match host name in match_ip list";
2810 /* Check the characters of the pattern to see if they comprise only letters,
2811 digits, full stops, and hyphens (the constituents of domain names). Allow
2812 underscores, as they are all too commonly found. Sigh. Also, if
2813 allow_utf8_domains is set, allow top-bit characters. */
2815 for (t = ss; *t != 0; t++)
2816 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2817 (!allow_utf8_domains || *t < 128)) break;
2819 /* If the pattern is a complete domain name, with no fancy characters, look up
2820 its IP address and match against that. Note that a multi-homed host will add
2821 items to the chain. */
2832 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2833 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2836 for (hh = &h; hh != NULL; hh = hh->next)
2838 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2842 if (rc == HOST_FIND_AGAIN) return DEFER;
2843 *error = string_sprintf("failed to find IP address for %s", ss);
2847 /* Almost all subsequent comparisons require the host name, and can be done
2848 using the general string matching function. When this function is called for
2849 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2850 must use sender_host_name and its aliases, looking them up if necessary. */
2852 if (cb->host_name != NULL) /* Explicit host name given */
2853 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2856 /* Host name not given; in principle we need the sender host name and its
2857 aliases. However, for query-style lookups, we do not need the name if the
2858 query does not contain $sender_host_name. From release 4.23, a reference to
2859 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2862 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2865 int partial, affixlen, starflags, id;
2868 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2871 if (id < 0) /* Unknown lookup type */
2873 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2874 search_error_message, ss);
2877 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2882 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2885 case DEFER: return DEFER;
2886 default: return FAIL;
2890 /* Not a query-style lookup; must ensure the host name is present, and then we
2891 do a check on the name and all its aliases. */
2893 if (sender_host_name == NULL)
2895 HDEBUG(D_host_lookup)
2896 debug_printf("sender host name required, to match against %s\n", ss);
2897 if (host_lookup_failed || host_name_lookup() != OK)
2899 *error = string_sprintf("failed to find host name for %s",
2900 sender_host_address);;
2903 host_build_sender_fullhost();
2906 /* Match on the sender host name, using the general matching function */
2908 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2912 case DEFER: return DEFER;
2915 /* If there are aliases, try matching on them. */
2917 aliases = sender_host_aliases;
2918 while (*aliases != NULL)
2920 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2923 case DEFER: return DEFER;
2932 /*************************************************
2933 * Check a specific host matches a host list *
2934 *************************************************/
2936 /* This function is passed a host list containing items in a number of
2937 different formats and the identity of a host. Its job is to determine whether
2938 the given host is in the set of hosts defined by the list. The host name is
2939 passed as a pointer so that it can be looked up if needed and not already
2940 known. This is commonly the case when called from verify_check_host() to check
2941 an incoming connection. When called from elsewhere the host name should usually
2944 This function is now just a front end to match_check_list(), which runs common
2945 code for scanning a list. We pass it the check_host() function to perform a
2949 listptr pointer to the host list
2950 cache_bits pointer to cache for named lists, or NULL
2951 host_name the host name or NULL, implying use sender_host_name and
2952 sender_host_aliases, looking them up if required
2953 host_address the IP address
2954 valueptr if not NULL, data from a lookup is passed back here
2956 Returns: OK if the host is in the defined set
2957 FAIL if the host is not in the defined set,
2958 DEFER if a data lookup deferred (not a host lookup)
2960 If the host name was needed in order to make a comparison, and could not be
2961 determined from the IP address, the result is FAIL unless the item
2962 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2965 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2966 uschar *host_name, uschar *host_address, uschar **valueptr)
2969 unsigned int *local_cache_bits = cache_bits;
2970 uschar *save_host_address = deliver_host_address;
2971 check_host_block cb;
2972 cb.host_name = host_name;
2973 cb.host_address = host_address;
2975 if (valueptr != NULL) *valueptr = NULL;
2977 /* If the host address starts off ::ffff: it is an IPv6 address in
2978 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2981 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2982 host_address + 7 : host_address;
2984 /* During the running of the check, put the IP address into $host_address. In
2985 the case of calls from the smtp transport, it will already be there. However,
2986 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2987 the safe side, any existing setting is preserved, though as I write this
2988 (November 2004) I can't see any cases where it is actually needed. */
2990 deliver_host_address = host_address;
2991 rc = match_check_list(
2992 listptr, /* the list */
2993 0, /* separator character */
2994 &hostlist_anchor, /* anchor pointer */
2995 &local_cache_bits, /* cache pointer */
2996 check_host, /* function for testing */
2997 &cb, /* argument for function */
2998 MCL_HOST, /* type of check */
2999 (host_address == sender_host_address)?
3000 US"host" : host_address, /* text for debugging */
3001 valueptr); /* where to pass back data */
3002 deliver_host_address = save_host_address;
3009 /*************************************************
3010 * Check the remote host matches a list *
3011 *************************************************/
3013 /* This is a front end to verify_check_this_host(), created because checking
3014 the remote host is a common occurrence. With luck, a good compiler will spot
3015 the tail recursion and optimize it. If there's no host address, this is
3016 command-line SMTP input - check against an empty string for the address.
3019 listptr pointer to the host list
3021 Returns: the yield of verify_check_this_host(),
3022 i.e. OK, FAIL, or DEFER
3026 verify_check_host(uschar **listptr)
3028 return verify_check_this_host(listptr, sender_host_cache, NULL,
3029 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3036 /*************************************************
3037 * Invert an IP address *
3038 *************************************************/
3040 /* Originally just used for DNS xBL lists, now also used for the
3041 reverse_ip expansion operator.
3044 buffer where to put the answer
3045 address the address to invert
3049 invert_address(uschar *buffer, uschar *address)
3052 uschar *bptr = buffer;
3054 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3055 to the IPv4 part only. */
3057 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3059 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3062 if (host_aton(address, bin) == 1)
3066 for (i = 0; i < 4; i++)
3068 sprintf(CS bptr, "%d.", x & 255);
3069 while (*bptr) bptr++;
3074 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3075 in any DNS black lists, and the format in which they will be looked up is
3076 unknown. This is just a guess. */
3082 for (j = 3; j >= 0; j--)
3085 for (i = 0; i < 8; i++)
3087 sprintf(CS bptr, "%x.", x & 15);
3088 while (*bptr) bptr++;
3095 /* Remove trailing period -- this is needed so that both arbitrary
3096 dnsbl keydomains and inverted addresses may be combined with the
3097 same format string, "%s.%s" */
3104 /*************************************************
3105 * Perform a single dnsbl lookup *
3106 *************************************************/
3108 /* This function is called from verify_check_dnsbl() below. It is also called
3109 recursively from within itself when domain and domain_txt are different
3110 pointers, in order to get the TXT record from the alternate domain.
3113 domain the outer dnsbl domain
3114 domain_txt alternate domain to lookup TXT record on success; when the
3115 same domain is to be used, domain_txt == domain (that is,
3116 the pointers must be identical, not just the text)
3117 keydomain the current keydomain (for debug message)
3118 prepend subdomain to lookup (like keydomain, but
3119 reversed if IP address)
3120 iplist the list of matching IP addresses, or NULL for "any"
3121 bitmask true if bitmask matching is wanted
3122 match_type condition for 'succeed' result
3123 0 => Any RR in iplist (=)
3124 1 => No RR in iplist (!=)
3125 2 => All RRs in iplist (==)
3126 3 => Some RRs not in iplist (!==)
3127 the two bits are defined as MT_NOT and MT_ALL
3128 defer_return what to return for a defer
3130 Returns: OK if lookup succeeded
3135 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3136 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3142 dnsbl_cache_block *cb;
3143 int old_pool = store_pool;
3144 uschar query[256]; /* DNS domain max length */
3146 /* Construct the specific query domainname */
3148 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3150 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3151 "(ignored): %s...", query);
3155 /* Look for this query in the cache. */
3157 t = tree_search(dnsbl_cache, query);
3159 /* If not cached from a previous lookup, we must do a DNS lookup, and
3160 cache the result in permanent memory. */
3164 store_pool = POOL_PERM;
3166 /* Set up a tree entry to cache the lookup */
3168 t = store_get(sizeof(tree_node) + Ustrlen(query));
3169 Ustrcpy(t->name, query);
3170 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3171 (void)tree_insertnode(&dnsbl_cache, t);
3173 /* Do the DNS loopup . */
3175 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3176 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3177 cb->text_set = FALSE;
3181 /* If the lookup succeeded, cache the RHS address. The code allows for
3182 more than one address - this was for complete generality and the possible
3183 use of A6 records. However, A6 records have been reduced to experimental
3184 status (August 2001) and may die out. So they may never get used at all,
3185 let alone in dnsbl records. However, leave the code here, just in case.
3187 Quite apart from one A6 RR generating multiple addresses, there are DNS
3188 lists that return more than one A record, so we must handle multiple
3189 addresses generated in that way as well. */
3191 if (cb->rc == DNS_SUCCEED)
3194 dns_address **addrp = &(cb->rhs);
3195 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3197 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3199 if (rr->type == T_A)
3201 dns_address *da = dns_address_from_rr(&dnsa, rr);
3205 while (da->next != NULL) da = da->next;
3206 addrp = &(da->next);
3211 /* If we didn't find any A records, change the return code. This can
3212 happen when there is a CNAME record but there are no A records for what
3215 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3218 store_pool = old_pool;
3221 /* Previous lookup was cached */
3225 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3229 /* We now have the result of the DNS lookup, either newly done, or cached
3230 from a previous call. If the lookup succeeded, check against the address
3231 list if there is one. This may be a positive equality list (introduced by
3232 "="), a negative equality list (introduced by "!="), a positive bitmask
3233 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3235 if (cb->rc == DNS_SUCCEED)
3237 dns_address *da = NULL;
3238 uschar *addlist = cb->rhs->address;
3240 /* For A and AAAA records, there may be multiple addresses from multiple
3241 records. For A6 records (currently not expected to be used) there may be
3242 multiple addresses from a single record. */
3244 for (da = cb->rhs->next; da != NULL; da = da->next)
3245 addlist = string_sprintf("%s, %s", addlist, da->address);
3247 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3250 /* Address list check; this can be either for equality, or via a bitmask.
3251 In the latter case, all the bits must match. */
3255 for (da = cb->rhs; da != NULL; da = da->next)
3259 uschar *ptr = iplist;
3262 /* Handle exact matching */
3266 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3268 if (Ustrcmp(CS da->address, ip) == 0) break;
3272 /* Handle bitmask matching */
3279 /* At present, all known DNS blocking lists use A records, with
3280 IPv4 addresses on the RHS encoding the information they return. I
3281 wonder if this will linger on as the last vestige of IPv4 when IPv6
3282 is ubiquitous? Anyway, for now we use paranoia code to completely
3283 ignore IPv6 addresses. The default mask is 0, which always matches.
3284 We change this only for IPv4 addresses in the list. */
3286 if (host_aton(da->address, address) == 1) mask = address[0];
3288 /* Scan the returned addresses, skipping any that are IPv6 */
3290 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3292 if (host_aton(ip, address) != 1) continue;
3293 if ((address[0] & mask) == address[0]) break;
3299 (a) An IP address in an any ('=') list matched, or
3300 (b) No IP address in an all ('==') list matched
3302 then we're done searching. */
3304 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3307 /* If da == NULL, either
3309 (a) No IP address in an any ('=') list matched, or
3310 (b) An IP address in an all ('==') list didn't match
3312 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3315 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3323 res = US"was no match";
3326 res = US"was an exclude match";
3329 res = US"was an IP address that did not match";
3332 res = US"were no IP addresses that did not match";
3335 debug_printf("=> but we are not accepting this block class because\n");
3336 debug_printf("=> there %s for %s%c%s\n",
3338 ((match_type & MT_ALL) == 0)? "" : "=",
3339 bitmask? '&' : '=', iplist);
3345 /* Either there was no IP list, or the record matched, implying that the
3346 domain is on the list. We now want to find a corresponding TXT record. If an
3347 alternate domain is specified for the TXT record, call this function
3348 recursively to look that up; this has the side effect of re-checking that
3349 there is indeed an A record at the alternate domain. */
3351 if (domain_txt != domain)
3352 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3353 FALSE, match_type, defer_return);
3355 /* If there is no alternate domain, look up a TXT record in the main domain
3356 if it has not previously been cached. */
3360 cb->text_set = TRUE;
3361 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3364 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3366 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3367 if (rr->type == T_TXT) break;
3370 int len = (rr->data)[0];
3371 if (len > 511) len = 127;
3372 store_pool = POOL_PERM;
3373 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3374 store_pool = old_pool;
3379 dnslist_value = addlist;
3380 dnslist_text = cb->text;
3384 /* There was a problem with the DNS lookup */
3386 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3388 log_write(L_dnslist_defer, LOG_MAIN,
3389 "DNS list lookup defer (probably timeout) for %s: %s", query,
3390 (defer_return == OK)? US"assumed in list" :
3391 (defer_return == FAIL)? US"assumed not in list" :
3392 US"returned DEFER");
3393 return defer_return;
3396 /* No entry was found in the DNS; continue for next domain */
3400 debug_printf("DNS lookup for %s failed\n", query);
3401 debug_printf("=> that means %s is not listed at %s\n",
3411 /*************************************************
3412 * Check host against DNS black lists *
3413 *************************************************/
3415 /* This function runs checks against a list of DNS black lists, until one
3416 matches. Each item on the list can be of the form
3418 domain=ip-address/key
3420 The domain is the right-most domain that is used for the query, for example,
3421 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3422 if the DNS lookup returns a matching IP address. Several addresses may be
3423 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3425 If no key is given, what is looked up in the domain is the inverted IP address
3426 of the current client host. If a key is given, it is used to construct the
3427 domain for the lookup. For example:
3429 dsn.rfc-ignorant.org/$sender_address_domain
3431 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3432 then we check for a TXT record for an error message, and if found, save its
3433 value in $dnslist_text. We also cache everything in a tree, to optimize
3436 The TXT record is normally looked up in the same domain as the A record, but
3437 when many lists are combined in a single DNS domain, this will not be a very
3438 specific message. It is possible to specify a different domain for looking up
3439 TXT records; this is given before the main domain, comma-separated. For
3442 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3443 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3445 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3447 Note: an address for testing RBL is 192.203.178.39
3448 Note: an address for testing DUL is 192.203.178.4
3449 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3452 listptr the domain/address/data list
3454 Returns: OK successful lookup (i.e. the address is on the list), or
3455 lookup deferred after +include_unknown
3456 FAIL name not found, or no data found for the given type, or
3457 lookup deferred after +exclude_unknown (default)
3458 DEFER lookup failure, if +defer_unknown was set
3462 verify_check_dnsbl(uschar **listptr)
3465 int defer_return = FAIL;
3466 uschar *list = *listptr;
3469 uschar buffer[1024];
3470 uschar revadd[128]; /* Long enough for IPv6 address */
3472 /* Indicate that the inverted IP address is not yet set up */
3476 /* In case this is the first time the DNS resolver is being used. */
3478 dns_init(FALSE, FALSE);
3480 /* Loop through all the domains supplied, until something matches */
3482 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3485 BOOL bitmask = FALSE;
3492 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3494 /* Deal with special values that change the behaviour on defer */
3496 if (domain[0] == '+')
3498 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3499 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3500 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3502 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3507 /* See if there's explicit data to be looked up */
3509 key = Ustrchr(domain, '/');
3510 if (key != NULL) *key++ = 0;
3512 /* See if there's a list of addresses supplied after the domain name. This is
3513 introduced by an = or a & character; if preceded by = we require all matches
3514 and if preceded by ! we invert the result. */
3516 iplist = Ustrchr(domain, '=');
3520 iplist = Ustrchr(domain, '&');
3523 if (iplist != NULL) /* Found either = or & */
3525 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3527 match_type |= MT_NOT;
3531 *iplist++ = 0; /* Terminate domain, move on */
3533 /* If we found = (bitmask == FALSE), check for == or =& */
3535 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3537 bitmask = *iplist++ == '&';
3538 match_type |= MT_ALL;
3542 /* If there is a comma in the domain, it indicates that a second domain for
3543 looking up TXT records is provided, before the main domain. Otherwise we must
3544 set domain_txt == domain. */
3546 domain_txt = domain;
3547 comma = Ustrchr(domain, ',');
3554 /* Check that what we have left is a sensible domain name. There is no reason
3555 why these domains should in fact use the same syntax as hosts and email
3556 domains, but in practice they seem to. However, there is little point in
3557 actually causing an error here, because that would no doubt hold up incoming
3558 mail. Instead, I'll just log it. */
3560 for (s = domain; *s != 0; s++)
3562 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3564 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3565 "strange characters - is this right?", domain);
3570 /* Check the alternate domain if present */
3572 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3574 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3576 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3577 "strange characters - is this right?", domain_txt);
3582 /* If there is no key string, construct the query by adding the domain name
3583 onto the inverted host address, and perform a single DNS lookup. */
3587 if (sender_host_address == NULL) return FAIL; /* can never match */
3588 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3589 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3590 iplist, bitmask, match_type, defer_return);
3593 dnslist_domain = string_copy(domain_txt);
3594 dnslist_matched = string_copy(sender_host_address);
3595 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3596 sender_host_address, dnslist_domain);
3598 if (rc != FAIL) return rc; /* OK or DEFER */
3601 /* If there is a key string, it can be a list of domains or IP addresses to
3602 be concatenated with the main domain. */
3609 uschar keybuffer[256];
3610 uschar keyrevadd[128];
3612 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3613 sizeof(keybuffer))) != NULL)
3615 uschar *prepend = keydomain;
3617 if (string_is_ip_address(keydomain, NULL) != 0)
3619 invert_address(keyrevadd, keydomain);
3620 prepend = keyrevadd;
3623 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3624 bitmask, match_type, defer_return);
3628 dnslist_domain = string_copy(domain_txt);
3629 dnslist_matched = string_copy(keydomain);
3630 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3631 keydomain, dnslist_domain);
3635 /* If the lookup deferred, remember this fact. We keep trying the rest
3636 of the list to see if we get a useful result, and if we don't, we return
3637 DEFER at the end. */
3639 if (rc == DEFER) defer = TRUE;
3640 } /* continue with next keystring domain/address */
3642 if (defer) return DEFER;
3644 } /* continue with next dnsdb outer domain */
3649 /* End of verify.c */