1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 address_item cutthrough_addr;
18 static smtp_outblock ctblock;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
44 /*************************************************
45 * Retrieve a callout cache record *
46 *************************************************/
48 /* If a record exists, check whether it has expired.
51 dbm_file an open hints file
53 type "address" or "domain"
54 positive_expire expire time for positive records
55 negative_expire expire time for negative records
57 Returns: the cache record if a non-expired one exists, else NULL
60 static dbdata_callout_cache *
61 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
62 int positive_expire, int negative_expire)
67 dbdata_callout_cache *cache_record;
69 cache_record = dbfn_read_with_length(dbm_file, key, &length);
71 if (cache_record == NULL)
73 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
77 /* We treat a record as "negative" if its result field is not positive, or if
78 it is a domain record and the postmaster field is negative. */
80 negative = cache_record->result != ccache_accept ||
81 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
82 expire = negative? negative_expire : positive_expire;
85 if (now - cache_record->time_stamp > expire)
87 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
91 /* If this is a non-reject domain record, check for the obsolete format version
92 that doesn't have the postmaster and random timestamps, by looking at the
93 length. If so, copy it to a new-style block, replicating the record's
94 timestamp. Then check the additional timestamps. (There's no point wasting
95 effort if connections are rejected.) */
97 if (type[0] == 'd' && cache_record->result != ccache_reject)
99 if (length == sizeof(dbdata_callout_cache_obs))
101 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
102 memcpy(new, cache_record, length);
103 new->postmaster_stamp = new->random_stamp = new->time_stamp;
107 if (now - cache_record->postmaster_stamp > expire)
108 cache_record->postmaster_result = ccache_unknown;
110 if (now - cache_record->random_stamp > expire)
111 cache_record->random_result = ccache_unknown;
114 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
120 /*************************************************
121 * Do callout verification for an address *
122 *************************************************/
124 /* This function is called from verify_address() when the address has routed to
125 a host list, and a callout has been requested. Callouts are expensive; that is
126 why a cache is used to improve the efficiency.
129 addr the address that's been routed
130 host_list the list of hosts to try
131 tf the transport feedback block
133 ifstring "interface" option from transport, or NULL
134 portstring "port" option from transport, or NULL
135 protocolstring "protocol" option from transport, or NULL
136 callout the per-command callout timeout
137 callout_overall the overall callout timeout (if < 0 use 4*callout)
138 callout_connect the callout connection timeout (if < 0 use callout)
139 options the verification options - these bits are used:
140 vopt_is_recipient => this is a recipient address
141 vopt_callout_no_cache => don't use callout cache
142 vopt_callout_fullpm => if postmaster check, do full one
143 vopt_callout_random => do the "random" thing
144 vopt_callout_recipsender => use real sender for recipient
145 vopt_callout_recippmaster => use postmaster for recipient
146 se_mailfrom MAIL FROM address for sender verify; NULL => ""
147 pm_mailfrom if non-NULL, do the postmaster check with this sender
149 Returns: OK/FAIL/DEFER
153 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
154 int callout, int callout_overall, int callout_connect, int options,
155 uschar *se_mailfrom, uschar *pm_mailfrom)
157 BOOL is_recipient = (options & vopt_is_recipient) != 0;
158 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
159 BOOL callout_random = (options & vopt_callout_random) != 0;
162 int old_domain_cache_result = ccache_accept;
165 uschar *from_address;
166 uschar *random_local_part = NULL;
167 uschar *save_deliver_domain = deliver_domain;
168 uschar **failure_ptr = is_recipient?
169 &recipient_verify_failure : &sender_verify_failure;
171 open_db *dbm_file = NULL;
172 dbdata_callout_cache new_domain_record;
173 dbdata_callout_cache_address new_address_record;
175 time_t callout_start_time;
177 new_domain_record.result = ccache_unknown;
178 new_domain_record.postmaster_result = ccache_unknown;
179 new_domain_record.random_result = ccache_unknown;
181 memset(&new_address_record, 0, sizeof(new_address_record));
183 /* For a recipient callout, the key used for the address cache record must
184 include the sender address if we are using the real sender in the callout,
185 because that may influence the result of the callout. */
187 address_key = addr->address;
192 if ((options & vopt_callout_recipsender) != 0)
194 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
195 from_address = sender_address;
197 else if ((options & vopt_callout_recippmaster) != 0)
199 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
200 qualify_domain_sender);
201 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
205 /* For a sender callout, we must adjust the key if the mailfrom address is not
210 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
211 if (from_address[0] != 0)
212 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
215 /* Open the callout cache database, it it exists, for reading only at this
216 stage, unless caching has been disabled. */
218 if (callout_no_cache)
220 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
222 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
224 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
227 /* If a cache database is available see if we can avoid the need to do an
228 actual callout by making use of previously-obtained data. */
230 if (dbm_file != NULL)
232 dbdata_callout_cache_address *cache_address_record;
233 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
234 addr->domain, US"domain",
235 callout_cache_domain_positive_expire,
236 callout_cache_domain_negative_expire);
238 /* If an unexpired cache record was found for this domain, see if the callout
239 process can be short-circuited. */
241 if (cache_record != NULL)
243 /* In most cases, if an early command (up to and including MAIL FROM:<>)
244 was rejected, there is no point carrying on. The callout fails. However, if
245 we are doing a recipient verification with use_sender or use_postmaster
246 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
247 will be using a non-empty sender. We have to remember this situation so as
248 not to disturb the cached domain value if this whole verification succeeds
249 (we don't want it turning into "accept"). */
251 old_domain_cache_result = cache_record->result;
253 if (cache_record->result == ccache_reject ||
254 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
256 setflag(addr, af_verify_nsfail);
258 debug_printf("callout cache: domain gave initial rejection, or "
259 "does not accept HELO or MAIL FROM:<>\n");
260 setflag(addr, af_verify_nsfail);
261 addr->user_message = US"(result of an earlier callout reused).";
263 *failure_ptr = US"mail";
267 /* If a previous check on a "random" local part was accepted, we assume
268 that the server does not do any checking on local parts. There is therefore
269 no point in doing the callout, because it will always be successful. If a
270 random check previously failed, arrange not to do it again, but preserve
271 the data in the new record. If a random check is required but hasn't been
272 done, skip the remaining cache processing. */
274 if (callout_random) switch(cache_record->random_result)
278 debug_printf("callout cache: domain accepts random addresses\n");
279 goto END_CALLOUT; /* Default yield is OK */
283 debug_printf("callout cache: domain rejects random addresses\n");
284 callout_random = FALSE;
285 new_domain_record.random_result = ccache_reject;
286 new_domain_record.random_stamp = cache_record->random_stamp;
291 debug_printf("callout cache: need to check random address handling "
292 "(not cached or cache expired)\n");
296 /* If a postmaster check is requested, but there was a previous failure,
297 there is again no point in carrying on. If a postmaster check is required,
298 but has not been done before, we are going to have to do a callout, so skip
299 remaining cache processing. */
301 if (pm_mailfrom != NULL)
303 if (cache_record->postmaster_result == ccache_reject)
305 setflag(addr, af_verify_pmfail);
307 debug_printf("callout cache: domain does not accept "
308 "RCPT TO:<postmaster@domain>\n");
310 *failure_ptr = US"postmaster";
311 setflag(addr, af_verify_pmfail);
312 addr->user_message = US"(result of earlier verification reused).";
315 if (cache_record->postmaster_result == ccache_unknown)
318 debug_printf("callout cache: need to check RCPT "
319 "TO:<postmaster@domain> (not cached or cache expired)\n");
323 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
324 postmaster check if the address itself has to be checked. Also ensure
325 that the value in the cache record is preserved (with its old timestamp).
328 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
329 "TO:<postmaster@domain>\n");
331 new_domain_record.postmaster_result = ccache_accept;
332 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
336 /* We can't give a result based on information about the domain. See if there
337 is an unexpired cache record for this specific address (combined with the
338 sender address if we are doing a recipient callout with a non-empty sender).
341 cache_address_record = (dbdata_callout_cache_address *)
342 get_callout_cache_record(dbm_file,
343 address_key, US"address",
344 callout_cache_positive_expire,
345 callout_cache_negative_expire);
347 if (cache_address_record != NULL)
349 if (cache_address_record->result == ccache_accept)
352 debug_printf("callout cache: address record is positive\n");
357 debug_printf("callout cache: address record is negative\n");
358 addr->user_message = US"Previous (cached) callout verification failure";
359 *failure_ptr = US"recipient";
365 /* Close the cache database while we actually do the callout for real. */
368 dbfn_close(dbm_file);
372 if (!addr->transport)
374 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
378 smtp_transport_options_block *ob =
379 (smtp_transport_options_block *)(addr->transport->options_block);
381 /* The information wasn't available in the cache, so we have to do a real
382 callout and save the result in the cache for next time, unless no_cache is set,
383 or unless we have a previously cached negative random result. If we are to test
384 with a random local part, ensure that such a local part is available. If not,
385 log the fact, but carry on without randomming. */
387 if (callout_random && callout_random_local_part != NULL)
389 random_local_part = expand_string(callout_random_local_part);
390 if (random_local_part == NULL)
391 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
392 "callout_random_local_part: %s", expand_string_message);
395 /* Default the connect and overall callout timeouts if not set, and record the
396 time we are starting so that we can enforce it. */
398 if (callout_overall < 0) callout_overall = 4 * callout;
399 if (callout_connect < 0) callout_connect = callout;
400 callout_start_time = time(NULL);
402 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
403 output because a callout might take some time. When PIPELINING is active and
404 there are many recipients, the total time for doing lots of callouts can add up
405 and cause the client to time out. So in this case we forgo the PIPELINING
408 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
410 /* Now make connections to the hosts and do real callouts. The list of hosts
411 is passed in as an argument. */
413 for (host = host_list; host != NULL && !done; host = host->next)
415 smtp_inblock inblock;
416 smtp_outblock outblock;
419 BOOL send_quit = TRUE;
420 uschar *active_hostname = smtp_active_hostname;
424 BOOL suppress_tls = FALSE;
425 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
426 uschar inbuffer[4096];
427 uschar outbuffer[1024];
428 uschar responsebuffer[4096];
430 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
431 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
433 /* Skip this host if we don't have an IP address for it. */
435 if (host->address == NULL)
437 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
442 /* Check the overall callout timeout */
444 if (time(NULL) - callout_start_time >= callout_overall)
446 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
450 /* Set IPv4 or IPv6 */
452 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
454 /* Expand and interpret the interface and port strings. The latter will not
455 be used if there is a host-specific port (e.g. from a manualroute router).
456 This has to be delayed till now, because they may expand differently for
457 different hosts. If there's a failure, log it, but carry on with the
460 deliver_host = host->name;
461 deliver_host_address = host->address;
462 deliver_domain = addr->domain;
464 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
466 !smtp_get_port(tf->port, addr, &port, US"callout"))
467 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
470 /* Set HELO string according to the protocol */
471 lmtp= Ustrcmp(tf->protocol, "lmtp") == 0;
472 smtps= Ustrcmp(tf->protocol, "smtps") == 0;
475 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
477 /* Set up the buffer for reading SMTP response packets. */
479 inblock.buffer = inbuffer;
480 inblock.buffersize = sizeof(inbuffer);
481 inblock.ptr = inbuffer;
482 inblock.ptrend = inbuffer;
484 /* Set up the buffer for holding SMTP commands while pipelining */
486 outblock.buffer = outbuffer;
487 outblock.buffersize = sizeof(outbuffer);
488 outblock.ptr = outbuffer;
489 outblock.cmd_count = 0;
490 outblock.authenticating = FALSE;
492 /* Reset the parameters of a TLS session */
493 tls_out.cipher = tls_out.peerdn = NULL;
495 /* Connect to the host; on failure, just loop for the next one, but we
496 set the error for the last one. Use the callout_connect timeout. */
498 tls_retry_connection:
500 inblock.sock = outblock.sock =
501 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
502 /* reconsider DSCP here */
503 if (inblock.sock < 0)
505 addr->message = string_sprintf("could not connect to %s [%s]: %s",
506 host->name, host->address, strerror(errno));
507 deliver_host = deliver_host_address = NULL;
508 deliver_domain = save_deliver_domain;
512 /* Expand the helo_data string to find the host name to use. */
514 if (tf->helo_data != NULL)
516 uschar *s = expand_string(tf->helo_data);
518 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
519 "helo_data value for callout: %s", addr->address,
520 expand_string_message);
521 else active_hostname = s;
524 deliver_host = deliver_host_address = NULL;
525 deliver_domain = save_deliver_domain;
527 /* Wait for initial response, and send HELO. The smtp_write_command()
528 function leaves its command in big_buffer. This is used in error responses.
529 Initialize it in case the connection is rejected. */
531 Ustrcpy(big_buffer, "initial connection");
533 /* Unless ssl-on-connect, wait for the initial greeting */
537 if (!smtps || (smtps && tls_out.active >= 0))
539 if (!(done= smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout)))
540 goto RESPONSE_FAILED;
542 /* Not worth checking greeting line for ESMTP support */
543 if (!(esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
544 host->name, host->address, NULL) != OK))
546 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
551 if (smtps && tls_out.active < 0) /* ssl-on-connect, first pass */
554 ob->tls_tempfail_tryclear = FALSE;
556 else /* all other cases */
561 if (!(done= smtp_write_command(&outblock, FALSE, "%s %s\r\n",
562 !esmtp? "HELO" : lmtp? "LHLO" : "EHLO", active_hostname) >= 0))
564 if (!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), '2', callout))
566 if (errno != 0 || responsebuffer[0] == 0 || lmtp || !esmtp || tls_out.active >= 0)
569 goto RESPONSE_FAILED;
575 goto esmtp_retry; /* fallback to HELO */
578 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
580 if (esmtp && !suppress_tls && tls_out.active < 0)
582 if (regex_STARTTLS == NULL) regex_STARTTLS =
583 regex_must_compile(US"\\n250[\\s\\-]STARTTLS(\\s|\\n|$)", FALSE, TRUE);
585 tls_offered = pcre_exec(regex_STARTTLS, NULL, CS responsebuffer,
586 Ustrlen(responsebuffer), 0, PCRE_EOPT, NULL, 0) >= 0;
593 /* If TLS is available on this connection attempt to
594 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
595 send another EHLO - the server may give a different answer in secure mode. We
596 use a separate buffer for reading the response to STARTTLS so that if it is
597 negative, the original EHLO data is available for subsequent analysis, should
598 the client not be required to use TLS. If the response is bad, copy the buffer
599 for error analysis. */
603 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
604 host->address, NULL) != OK &&
605 verify_check_this_host(&(ob->hosts_verify_avoid_tls), NULL, host->name,
606 host->address, NULL) != OK
609 uschar buffer2[4096];
611 && !(done= smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") >= 0))
614 /* If there is an I/O error, transmission of this message is deferred. If
615 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
616 false, we also defer. However, if there is a temporary rejection of STARTTLS
617 and tls_tempfail_tryclear is true, or if there is an outright rejection of
618 STARTTLS, we carry on. This means we will try to send the message in clear,
619 unless the host is in hosts_require_tls (tested below). */
621 if (!smtps && !smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
622 ob->command_timeout))
624 if (errno != 0 || buffer2[0] == 0 ||
625 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
627 Ustrncpy(responsebuffer, buffer2, sizeof(responsebuffer));
629 goto RESPONSE_FAILED;
633 /* STARTTLS accepted or ssl-on-connect: try to negotiate a TLS session. */
636 int rc = tls_client_start(inblock.sock, host, addr,
637 ob->tls_certificate, ob->tls_privatekey,
639 ob->tls_verify_certificates, ob->tls_crl,
640 ob->tls_require_ciphers,
641 #ifdef EXPERIMENTAL_OCSP
642 ob->hosts_require_ocsp,
644 ob->tls_dh_min_bits, callout);
646 /* TLS negotiation failed; give an error. Try in clear on a new connection,
647 if the options permit it for this host. */
650 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
651 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
652 host->address, NULL) != OK)
654 (void)close(inblock.sock);
655 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
656 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
658 goto tls_retry_connection;
660 /*save_errno = ERRNO_TLSFAILURE;*/
661 /*message = US"failure while setting up TLS session";*/
667 /* TLS session is set up. Copy info for logging. */
668 addr->cipher = tls_out.cipher;
669 addr->peerdn = tls_out.peerdn;
671 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
673 goto smtps_redo_greeting;
675 /* For STARTTLS we need to redo EHLO */
680 /* If the host is required to use a secure channel, ensure that we have one. */
681 if (tls_out.active < 0)
682 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
683 host->address, NULL) == OK)
685 /*save_errno = ERRNO_TLSREQUIRED;*/
686 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
687 host->name, host->address,
688 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
693 #endif /*SUPPORT_TLS*/
695 done = TRUE; /* so far so good; have response to HELO */
697 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING, AUTH */
698 /* If we haven't authenticated, but are required to, give up. */
700 /*XXX "filter command specified for this transport" ??? */
701 /* for now, transport_filter by cutthrough-delivery is not supported */
702 /* Need proper integration with the proper transport mechanism. */
709 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
712 /* Failure to accept HELO is cached; this blocks the whole domain for all
713 senders. I/O errors and defer responses are not cached. */
717 *failure_ptr = US"mail"; /* At or before MAIL */
718 if (errno == 0 && responsebuffer[0] == '5')
720 setflag(addr, af_verify_nsfail);
721 new_domain_record.result = ccache_reject;
727 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
728 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
730 /* Copy AUTH info for logging */
731 ( (addr->authenticator = client_authenticator),
732 (addr->auth_id = client_authenticated_id),
734 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
735 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
738 ( (addr->auth_sndr = client_authenticated_sender),
740 /* Send the MAIL command */
741 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
742 from_address, responsebuffer) >= 0)
745 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
748 /* If the host does not accept MAIL FROM:<>, arrange to cache this
749 information, but again, don't record anything for an I/O error or a defer. Do
750 not cache rejections of MAIL when a non-empty sender has been used, because
751 that blocks the whole domain for all senders. */
755 *failure_ptr = US"mail"; /* At or before MAIL */
756 if (errno == 0 && responsebuffer[0] == '5')
758 setflag(addr, af_verify_nsfail);
759 if (from_address[0] == 0)
760 new_domain_record.result = ccache_reject_mfnull;
764 /* Otherwise, proceed to check a "random" address (if required), then the
765 given address, and the postmaster address (if required). Between each check,
766 issue RSET, because some servers accept only one recipient after MAIL
769 Before doing this, set the result in the domain cache record to "accept",
770 unless its previous value was ccache_reject_mfnull. In that case, the domain
771 rejects MAIL FROM:<> and we want to continue to remember that. When that is
772 the case, we have got here only in the case of a recipient verification with
773 a non-null sender. */
777 new_domain_record.result =
778 (old_domain_cache_result == ccache_reject_mfnull)?
779 ccache_reject_mfnull: ccache_accept;
781 /* Do the random local part check first */
783 if (random_local_part != NULL)
785 uschar randombuffer[1024];
787 smtp_write_command(&outblock, FALSE,
788 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
789 addr->domain) >= 0 &&
790 smtp_read_response(&inblock, randombuffer,
791 sizeof(randombuffer), '2', callout);
793 /* Remember when we last did a random test */
795 new_domain_record.random_stamp = time(NULL);
797 /* If accepted, we aren't going to do any further tests below. */
801 new_domain_record.random_result = ccache_accept;
804 /* Otherwise, cache a real negative response, and get back to the right
805 state to send RCPT. Unless there's some problem such as a dropped
806 connection, we expect to succeed, because the commands succeeded above. */
810 if (randombuffer[0] == '5')
811 new_domain_record.random_result = ccache_reject;
814 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
815 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
818 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
819 from_address) >= 0 &&
820 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
823 else done = FALSE; /* Some timeout/connection problem */
826 /* If the host is accepting all local parts, as determined by the "random"
827 check, we don't need to waste time doing any further checking. */
829 if (new_domain_record.random_result != ccache_accept && done)
831 /* Get the rcpt_include_affixes flag from the transport if there is one,
832 but assume FALSE if there is not. */
835 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
836 transport_rcpt_address(addr,
837 (addr->transport == NULL)? FALSE :
838 addr->transport->rcpt_include_affixes)) >= 0 &&
839 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
843 new_address_record.result = ccache_accept;
844 else if (errno == 0 && responsebuffer[0] == '5')
846 *failure_ptr = US"recipient";
847 new_address_record.result = ccache_reject;
850 /* Do postmaster check if requested; if a full check is required, we
851 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
853 if (done && pm_mailfrom != NULL)
855 /*XXX not suitable for cutthrough - sequencing problems */
856 cutthrough_delivery= FALSE;
857 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
860 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
861 smtp_read_response(&inblock, responsebuffer,
862 sizeof(responsebuffer), '2', callout) &&
864 smtp_write_command(&outblock, FALSE,
865 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
866 smtp_read_response(&inblock, responsebuffer,
867 sizeof(responsebuffer), '2', callout) &&
869 /* First try using the current domain */
872 smtp_write_command(&outblock, FALSE,
873 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
874 smtp_read_response(&inblock, responsebuffer,
875 sizeof(responsebuffer), '2', callout)
880 /* If that doesn't work, and a full check is requested,
881 try without the domain. */
884 (options & vopt_callout_fullpm) != 0 &&
885 smtp_write_command(&outblock, FALSE,
886 "RCPT TO:<postmaster>\r\n") >= 0 &&
887 smtp_read_response(&inblock, responsebuffer,
888 sizeof(responsebuffer), '2', callout)
891 /* Sort out the cache record */
893 new_domain_record.postmaster_stamp = time(NULL);
896 new_domain_record.postmaster_result = ccache_accept;
897 else if (errno == 0 && responsebuffer[0] == '5')
899 *failure_ptr = US"postmaster";
900 setflag(addr, af_verify_pmfail);
901 new_domain_record.postmaster_result = ccache_reject;
904 } /* Random not accepted */
905 } /* MAIL FROM: accepted */
907 /* For any failure of the main check, other than a negative response, we just
908 close the connection and carry on. We can identify a negative response by the
909 fact that errno is zero. For I/O errors it will be non-zero
911 Set up different error texts for logging and for sending back to the caller
912 as an SMTP response. Log in all cases, using a one-line format. For sender
913 callouts, give a full response to the caller, but for recipient callouts,
914 don't give the IP address because this may be an internal host whose identity
915 is not to be widely broadcast. */
919 if (errno == ETIMEDOUT)
921 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
926 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
929 string_sprintf("response to \"%s\" from %s [%s] was: %s",
930 big_buffer, host->name, host->address,
931 string_printing(responsebuffer));
933 addr->user_message = is_recipient?
934 string_sprintf("Callout verification failed:\n%s", responsebuffer)
936 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
937 host->address, big_buffer, responsebuffer);
939 /* Hard rejection ends the process */
941 if (responsebuffer[0] == '5') /* Address rejected */
949 /* End the SMTP conversation and close the connection. */
951 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
952 and we have no cutthrough conn so far
953 here is where we want to leave the conn open */
954 if ( cutthrough_delivery
957 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
958 && !random_local_part
963 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
964 cutthrough_addr = *addr; /* Save the address_item for later logging */
965 cutthrough_addr.host_used = store_get(sizeof(host_item));
966 cutthrough_addr.host_used->name = host->name;
967 cutthrough_addr.host_used->address = host->address;
968 cutthrough_addr.host_used->port = port;
970 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
971 ctblock.buffer = ctbuffer;
972 ctblock.buffersize = sizeof(ctbuffer);
973 ctblock.ptr = ctbuffer;
974 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
975 ctblock.sock = cutthrough_fd;
979 /* Ensure no cutthrough on multiple address verifies */
980 if (options & vopt_callout_recipsender)
981 cancel_cutthrough_connection("multiple verify calls");
982 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
985 tls_close(FALSE, TRUE);
987 (void)close(inblock.sock);
990 } /* Loop through all hosts, while !done */
993 /* If we get here with done == TRUE, a successful callout happened, and yield
994 will be set OK or FAIL according to the response to the RCPT command.
995 Otherwise, we looped through the hosts but couldn't complete the business.
996 However, there may be domain-specific information to cache in both cases.
998 The value of the result field in the new_domain record is ccache_unknown if
999 there was an error before or with MAIL FROM:, and errno was not zero,
1000 implying some kind of I/O error. We don't want to write the cache in that case.
1001 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1003 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1005 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1008 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1012 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1013 (int)sizeof(dbdata_callout_cache));
1014 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1015 " result=%d postmaster=%d random=%d\n",
1016 new_domain_record.result,
1017 new_domain_record.postmaster_result,
1018 new_domain_record.random_result);
1022 /* If a definite result was obtained for the callout, cache it unless caching
1027 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1029 if (dbm_file == NULL)
1030 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1031 if (dbm_file == NULL)
1033 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1037 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1038 (int)sizeof(dbdata_callout_cache_address));
1039 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1040 (new_address_record.result == ccache_accept)? "positive" : "negative");
1045 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1046 temporary error. If there was only one host, and a response was received, leave
1047 it alone if supplying details. Otherwise, give a generic response. */
1051 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1052 is_recipient? "recipient" : "sender");
1055 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1057 addr->user_message = (!smtp_return_error_details)? dullmsg :
1058 string_sprintf("%s for <%s>.\n"
1059 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1060 "they may be permanently unreachable from this server. In the latter case,\n%s",
1061 dullmsg, addr->address,
1063 "the address will never be accepted."
1065 "you need to change the address or create an MX record for its domain\n"
1066 "if it is supposed to be generally accessible from the Internet.\n"
1067 "Talk to your mail administrator for details.");
1069 /* Force a specific error code */
1071 addr->basic_errno = ERRNO_CALLOUTDEFER;
1074 /* Come here from within the cache-reading code on fast-track exit. */
1077 if (dbm_file != NULL) dbfn_close(dbm_file);
1083 /* Called after recipient-acl to get a cutthrough connection open when
1084 one was requested and a recipient-verify wasn't subsequently done.
1087 open_cutthrough_connection( address_item * addr )
1091 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1092 /* We must use a copy of the address for verification, because it might
1096 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1097 (void) verify_address(&addr2, NULL,
1098 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1099 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1101 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1107 /* Send given number of bytes from the buffer */
1109 cutthrough_send(int n)
1111 if(cutthrough_fd < 0)
1116 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1118 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1121 transport_count += n;
1122 ctblock.ptr= ctblock.buffer;
1126 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1133 _cutthrough_puts(uschar * cp, int n)
1137 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1138 if(!cutthrough_send(ctblock.buffersize))
1141 *ctblock.ptr++ = *cp++;
1146 /* Buffered output of counted data block. Return boolean success */
1148 cutthrough_puts(uschar * cp, int n)
1150 if (cutthrough_fd < 0) return TRUE;
1151 if (_cutthrough_puts(cp, n)) return TRUE;
1152 cancel_cutthrough_connection("transmit failed");
1158 _cutthrough_flush_send( void )
1160 int n= ctblock.ptr-ctblock.buffer;
1163 if(!cutthrough_send(n))
1169 /* Send out any bufferred output. Return boolean success. */
1171 cutthrough_flush_send( void )
1173 if (_cutthrough_flush_send()) return TRUE;
1174 cancel_cutthrough_connection("transmit failed");
1180 cutthrough_put_nl( void )
1182 return cutthrough_puts(US"\r\n", 2);
1186 /* Get and check response from cutthrough target */
1188 cutthrough_response(char expect, uschar ** copy)
1190 smtp_inblock inblock;
1191 uschar inbuffer[4096];
1192 uschar responsebuffer[4096];
1194 inblock.buffer = inbuffer;
1195 inblock.buffersize = sizeof(inbuffer);
1196 inblock.ptr = inbuffer;
1197 inblock.ptrend = inbuffer;
1198 inblock.sock = cutthrough_fd;
1199 /* this relies on (inblock.sock == tls_out.active) */
1200 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1201 cancel_cutthrough_connection("target timeout on read");
1206 *copy= cp= string_copy(responsebuffer);
1207 /* Trim the trailing end of line */
1208 cp += Ustrlen(responsebuffer);
1209 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1210 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1213 return responsebuffer[0];
1217 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1219 cutthrough_predata( void )
1221 if(cutthrough_fd < 0)
1224 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1225 cutthrough_puts(US"DATA\r\n", 6);
1226 cutthrough_flush_send();
1228 /* Assume nothing buffered. If it was it gets ignored. */
1229 return cutthrough_response('3', NULL) == '3';
1233 /* Buffered send of headers. Return success boolean. */
1234 /* Expands newlines to wire format (CR,NL). */
1235 /* Also sends header-terminating blank line. */
1237 cutthrough_headers_send( void )
1240 uschar * cp1, * cp2;
1242 if(cutthrough_fd < 0)
1245 for(h= header_list; h != NULL; h= h->next)
1246 if(h->type != htype_old && h->text != NULL)
1247 for (cp1 = h->text; *cp1 && (cp2 = Ustrchr(cp1, '\n')); cp1 = cp2+1)
1248 if( !cutthrough_puts(cp1, cp2-cp1)
1249 || !cutthrough_put_nl())
1252 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>>(nl)\n");
1253 return cutthrough_put_nl();
1258 close_cutthrough_connection( const char * why )
1260 if(cutthrough_fd >= 0)
1262 /* We could be sending this after a bunch of data, but that is ok as
1263 the only way to cancel the transfer in dataphase is to drop the tcp
1264 conn before the final dot.
1266 ctblock.ptr = ctbuffer;
1267 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1268 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1269 _cutthrough_flush_send();
1270 /* No wait for response */
1273 tls_close(FALSE, TRUE);
1275 (void)close(cutthrough_fd);
1277 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1279 ctblock.ptr = ctbuffer;
1283 cancel_cutthrough_connection( const char * why )
1285 close_cutthrough_connection(why);
1286 cutthrough_delivery= FALSE;
1292 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1293 Log an OK response as a transmission.
1294 Close the connection.
1295 Return smtp response-class digit.
1298 cutthrough_finaldot( void )
1300 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1302 /* Assume data finshed with new-line */
1303 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1304 return cutthrough_addr.message;
1306 switch(cutthrough_response('2', &cutthrough_addr.message))
1309 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1310 close_cutthrough_connection("delivered");
1314 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1318 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1324 return cutthrough_addr.message;
1329 /*************************************************
1330 * Copy error to toplevel address *
1331 *************************************************/
1333 /* This function is used when a verify fails or defers, to ensure that the
1334 failure or defer information is in the original toplevel address. This applies
1335 when an address is redirected to a single new address, and the failure or
1336 deferral happens to the child address.
1339 vaddr the verify address item
1340 addr the final address item
1343 Returns: the value of YIELD
1347 copy_error(address_item *vaddr, address_item *addr, int yield)
1351 vaddr->message = addr->message;
1352 vaddr->user_message = addr->user_message;
1353 vaddr->basic_errno = addr->basic_errno;
1354 vaddr->more_errno = addr->more_errno;
1355 vaddr->p.address_data = addr->p.address_data;
1356 copyflag(vaddr, addr, af_pass_message);
1364 /**************************************************
1365 * printf that automatically handles TLS if needed *
1366 ***************************************************/
1368 /* This function is used by verify_address() as a substitute for all fprintf()
1369 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1370 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1371 that assumes that we always use the smtp_out FILE* when not using TLS or the
1372 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1373 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1377 f the candidate FILE* to write to
1378 format format string
1379 ... optional arguments
1385 static void PRINTF_FUNCTION(2,3)
1386 respond_printf(FILE *f, const char *format, ...)
1390 va_start(ap, format);
1391 if (smtp_out && (f == smtp_out))
1392 smtp_vprintf(format, ap);
1394 vfprintf(f, format, ap);
1400 /*************************************************
1401 * Verify an email address *
1402 *************************************************/
1404 /* This function is used both for verification (-bv and at other times) and
1405 address testing (-bt), which is indicated by address_test_mode being set.
1408 vaddr contains the address to verify; the next field in this block
1410 f if not NULL, write the result to this file
1411 options various option bits:
1412 vopt_fake_sender => this sender verify is not for the real
1413 sender (it was verify=sender=xxxx or an address from a
1414 header line) - rewriting must not change sender_address
1415 vopt_is_recipient => this is a recipient address, otherwise
1416 it's a sender address - this affects qualification and
1417 rewriting and messages from callouts
1418 vopt_qualify => qualify an unqualified address; else error
1419 vopt_expn => called from SMTP EXPN command
1420 vopt_success_on_redirect => when a new address is generated
1421 the verification instantly succeeds
1423 These ones are used by do_callout() -- the options variable
1426 vopt_callout_fullpm => if postmaster check, do full one
1427 vopt_callout_no_cache => don't use callout cache
1428 vopt_callout_random => do the "random" thing
1429 vopt_callout_recipsender => use real sender for recipient
1430 vopt_callout_recippmaster => use postmaster for recipient
1432 callout if > 0, specifies that callout is required, and gives timeout
1433 for individual commands
1434 callout_overall if > 0, gives overall timeout for the callout function;
1435 if < 0, a default is used (see do_callout())
1436 callout_connect the connection timeout for callouts
1437 se_mailfrom when callout is requested to verify a sender, use this
1438 in MAIL FROM; NULL => ""
1439 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1440 thing and use this as the sender address (may be "")
1442 routed if not NULL, set TRUE if routing succeeded, so we can
1443 distinguish between routing failed and callout failed
1445 Returns: OK address verified
1446 FAIL address failed to verify
1447 DEFER can't tell at present
1451 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1452 int callout_overall, int callout_connect, uschar *se_mailfrom,
1453 uschar *pm_mailfrom, BOOL *routed)
1456 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1457 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1458 BOOL expn = (options & vopt_expn) != 0;
1459 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1462 int verify_type = expn? v_expn :
1463 address_test_mode? v_none :
1464 is_recipient? v_recipient : v_sender;
1465 address_item *addr_list;
1466 address_item *addr_new = NULL;
1467 address_item *addr_remote = NULL;
1468 address_item *addr_local = NULL;
1469 address_item *addr_succeed = NULL;
1470 uschar **failure_ptr = is_recipient?
1471 &recipient_verify_failure : &sender_verify_failure;
1472 uschar *ko_prefix, *cr;
1473 uschar *address = vaddr->address;
1474 uschar *save_sender;
1475 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1477 /* Clear, just in case */
1479 *failure_ptr = NULL;
1481 /* Set up a prefix and suffix for error message which allow us to use the same
1482 output statements both in EXPN mode (where an SMTP response is needed) and when
1483 debugging with an output file. */
1487 ko_prefix = US"553 ";
1490 else ko_prefix = cr = US"";
1492 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1494 if (parse_find_at(address) == NULL)
1496 if ((options & vopt_qualify) == 0)
1499 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1500 ko_prefix, address, cr);
1501 *failure_ptr = US"qualify";
1504 address = rewrite_address_qualify(address, is_recipient);
1509 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1510 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1513 /* Rewrite and report on it. Clear the domain and local part caches - these
1514 may have been set by domains and local part tests during an ACL. */
1516 if (global_rewrite_rules != NULL)
1518 uschar *old = address;
1519 address = rewrite_address(address, is_recipient, FALSE,
1520 global_rewrite_rules, rewrite_existflags);
1523 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1524 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1525 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1529 /* If this is the real sender address, we must update sender_address at
1530 this point, because it may be referred to in the routers. */
1532 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1533 sender_address = address;
1535 /* If the address was rewritten to <> no verification can be done, and we have
1536 to return OK. This rewriting is permitted only for sender addresses; for other
1537 addresses, such rewriting fails. */
1539 if (address[0] == 0) return OK;
1541 /* Flip the legacy TLS-related variables over to the outbound set in case
1542 they're used in the context of a transport used by verification. Reset them
1543 at exit from this routine. */
1545 modify_variable(US"tls_bits", &tls_out.bits);
1546 modify_variable(US"tls_certificate_verified", &tls_out.certificate_verified);
1547 modify_variable(US"tls_cipher", &tls_out.cipher);
1548 modify_variable(US"tls_peerdn", &tls_out.peerdn);
1549 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1550 modify_variable(US"tls_sni", &tls_out.sni);
1553 /* Save a copy of the sender address for re-instating if we change it to <>
1554 while verifying a sender address (a nice bit of self-reference there). */
1556 save_sender = sender_address;
1558 /* Update the address structure with the possibly qualified and rewritten
1559 address. Set it up as the starting address on the chain of new addresses. */
1561 vaddr->address = address;
1564 /* We need a loop, because an address can generate new addresses. We must also
1565 cope with generated pipes and files at the top level. (See also the code and
1566 comment in deliver.c.) However, it is usually the case that the router for
1567 user's .forward files has its verify flag turned off.
1569 If an address generates more than one child, the loop is used only when
1570 full_info is set, and this can only be set locally. Remote enquiries just get
1571 information about the top level address, not anything that it generated. */
1573 while (addr_new != NULL)
1576 address_item *addr = addr_new;
1578 addr_new = addr->next;
1583 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1584 debug_printf("Considering %s\n", addr->address);
1587 /* Handle generated pipe, file or reply addresses. We don't get these
1588 when handling EXPN, as it does only one level of expansion. */
1590 if (testflag(addr, af_pfr))
1597 if (addr->address[0] == '>')
1599 allow = testflag(addr, af_allow_reply);
1600 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1604 allow = (addr->address[0] == '|')?
1605 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1606 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1609 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1610 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1611 "%s\n", addr->message);
1613 fprintf(f, "\n transport = %s\n", addr->transport->name);
1615 fprintf(f, " *** forbidden ***\n");
1620 /* Just in case some router parameter refers to it. */
1622 return_path = (addr->p.errors_address != NULL)?
1623 addr->p.errors_address : sender_address;
1625 /* Split the address into domain and local part, handling the %-hack if
1626 necessary, and then route it. While routing a sender address, set
1627 $sender_address to <> because that is what it will be if we were trying to
1628 send a bounce to the sender. */
1630 if (routed != NULL) *routed = FALSE;
1631 if ((rc = deliver_split_address(addr)) == OK)
1633 if (!is_recipient) sender_address = null_sender;
1634 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1635 &addr_succeed, verify_type);
1636 sender_address = save_sender; /* Put back the real sender */
1639 /* If routing an address succeeded, set the flag that remembers, for use when
1640 an ACL cached a sender verify (in case a callout fails). Then if routing set
1641 up a list of hosts or the transport has a host list, and the callout option
1642 is set, and we aren't in a host checking run, do the callout verification,
1643 and set another flag that notes that a callout happened. */
1647 if (routed != NULL) *routed = TRUE;
1650 host_item *host_list = addr->host_list;
1652 /* Make up some data for use in the case where there is no remote
1655 transport_feedback tf = {
1656 NULL, /* interface (=> any) */
1657 US"smtp", /* port */
1658 US"smtp", /* protocol */
1660 US"$smtp_active_hostname", /* helo_data */
1661 FALSE, /* hosts_override */
1662 FALSE, /* hosts_randomize */
1663 FALSE, /* gethostbyname */
1664 TRUE, /* qualify_single */
1665 FALSE /* search_parents */
1668 /* If verification yielded a remote transport, we want to use that
1669 transport's options, so as to mimic what would happen if we were really
1670 sending a message to this address. */
1672 if (addr->transport != NULL && !addr->transport->info->local)
1674 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1676 /* If the transport has hosts and the router does not, or if the
1677 transport is configured to override the router's hosts, we must build a
1678 host list of the transport's hosts, and find the IP addresses */
1680 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1683 uschar *save_deliver_domain = deliver_domain;
1684 uschar *save_deliver_localpart = deliver_localpart;
1686 host_list = NULL; /* Ignore the router's hosts */
1688 deliver_domain = addr->domain;
1689 deliver_localpart = addr->local_part;
1690 s = expand_string(tf.hosts);
1691 deliver_domain = save_deliver_domain;
1692 deliver_localpart = save_deliver_localpart;
1696 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1697 "\"%s\" in %s transport for callout: %s", tf.hosts,
1698 addr->transport->name, expand_string_message);
1703 uschar *canonical_name;
1704 host_item *host, *nexthost;
1705 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1707 /* Just ignore failures to find a host address. If we don't manage
1708 to find any addresses, the callout will defer. Note that more than
1709 one address may be found for a single host, which will result in
1710 additional host items being inserted into the chain. Hence we must
1711 save the next host first. */
1713 flags = HOST_FIND_BY_A;
1714 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1715 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1717 for (host = host_list; host != NULL; host = nexthost)
1719 nexthost = host->next;
1720 if (tf.gethostbyname ||
1721 string_is_ip_address(host->name, NULL) != 0)
1722 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1724 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1725 &canonical_name, NULL);
1731 /* Can only do a callout if we have at least one host! If the callout
1732 fails, it will have set ${sender,recipient}_verify_failure. */
1734 if (host_list != NULL)
1736 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1737 if (host_checking && !host_checking_callout)
1740 debug_printf("... callout omitted by default when host testing\n"
1741 "(Use -bhc if you want the callouts to happen.)\n");
1746 deliver_set_expansions(addr);
1748 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1749 callout_connect, options, se_mailfrom, pm_mailfrom);
1754 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1755 "transport provided a host list\n");
1760 /* Otherwise, any failure is a routing failure */
1762 else *failure_ptr = US"route";
1764 /* A router may return REROUTED if it has set up a child address as a result
1765 of a change of domain name (typically from widening). In this case we always
1766 want to continue to verify the new child. */
1768 if (rc == REROUTED) continue;
1770 /* Handle hard failures */
1777 address_item *p = addr->parent;
1779 respond_printf(f, "%s%s %s", ko_prefix,
1780 full_info? addr->address : address,
1781 address_test_mode? "is undeliverable" : "failed to verify");
1782 if (!expn && admin_user)
1784 if (addr->basic_errno > 0)
1785 respond_printf(f, ": %s", strerror(addr->basic_errno));
1786 if (addr->message != NULL)
1787 respond_printf(f, ": %s", addr->message);
1790 /* Show parents iff doing full info */
1792 if (full_info) while (p != NULL)
1794 respond_printf(f, "%s\n <-- %s", cr, p->address);
1797 respond_printf(f, "%s\n", cr);
1799 cancel_cutthrough_connection("routing hard fail");
1803 yield = copy_error(vaddr, addr, FAIL);
1811 else if (rc == DEFER)
1816 address_item *p = addr->parent;
1817 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1818 full_info? addr->address : address);
1819 if (!expn && admin_user)
1821 if (addr->basic_errno > 0)
1822 respond_printf(f, ": %s", strerror(addr->basic_errno));
1823 if (addr->message != NULL)
1824 respond_printf(f, ": %s", addr->message);
1825 else if (addr->basic_errno <= 0)
1826 respond_printf(f, ": unknown error");
1829 /* Show parents iff doing full info */
1831 if (full_info) while (p != NULL)
1833 respond_printf(f, "%s\n <-- %s", cr, p->address);
1836 respond_printf(f, "%s\n", cr);
1838 cancel_cutthrough_connection("routing soft fail");
1842 yield = copy_error(vaddr, addr, DEFER);
1845 else if (yield == OK) yield = DEFER;
1848 /* If we are handling EXPN, we do not want to continue to route beyond
1849 the top level (whose address is in "address"). */
1853 uschar *ok_prefix = US"250-";
1854 if (addr_new == NULL)
1856 if (addr_local == NULL && addr_remote == NULL)
1857 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1859 respond_printf(f, "250 <%s>\r\n", address);
1861 else while (addr_new != NULL)
1863 address_item *addr2 = addr_new;
1864 addr_new = addr2->next;
1865 if (addr_new == NULL) ok_prefix = US"250 ";
1866 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1872 /* Successful routing other than EXPN. */
1876 /* Handle successful routing when short info wanted. Otherwise continue for
1877 other (generated) addresses. Short info is the operational case. Full info
1878 can be requested only when debug_selector != 0 and a file is supplied.
1880 There is a conflict between the use of aliasing as an alternate email
1881 address, and as a sort of mailing list. If an alias turns the incoming
1882 address into just one address (e.g. J.Caesar->jc44) you may well want to
1883 carry on verifying the generated address to ensure it is valid when
1884 checking incoming mail. If aliasing generates multiple addresses, you
1885 probably don't want to do this. Exim therefore treats the generation of
1886 just a single new address as a special case, and continues on to verify the
1887 generated address. */
1889 if (!full_info && /* Stop if short info wanted AND */
1890 (((addr_new == NULL || /* No new address OR */
1891 addr_new->next != NULL || /* More than one new address OR */
1892 testflag(addr_new, af_pfr))) /* New address is pfr */
1894 (addr_new != NULL && /* At least one new address AND */
1895 success_on_redirect))) /* success_on_redirect is set */
1897 if (f != NULL) fprintf(f, "%s %s\n", address,
1898 address_test_mode? "is deliverable" : "verified");
1900 /* If we have carried on to verify a child address, we want the value
1901 of $address_data to be that of the child */
1903 vaddr->p.address_data = addr->p.address_data;
1908 } /* Loop for generated addresses */
1910 /* Display the full results of the successful routing, including any generated
1911 addresses. Control gets here only when full_info is set, which requires f not
1912 to be NULL, and this occurs only when a top-level verify is called with the
1913 debugging switch on.
1915 If there are no local and no remote addresses, and there were no pipes, files,
1916 or autoreplies, and there were no errors or deferments, the message is to be
1917 discarded, usually because of the use of :blackhole: in an alias file. */
1919 if (allok && addr_local == NULL && addr_remote == NULL)
1921 fprintf(f, "mail to %s is discarded\n", address);
1925 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1927 while (addr_list != NULL)
1929 address_item *addr = addr_list;
1930 address_item *p = addr->parent;
1931 addr_list = addr->next;
1933 fprintf(f, "%s", CS addr->address);
1934 #ifdef EXPERIMENTAL_SRS
1935 if(addr->p.srs_sender)
1936 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1939 /* If the address is a duplicate, show something about it. */
1941 if (!testflag(addr, af_pfr))
1944 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1945 fprintf(f, " [duplicate, would not be delivered]");
1946 else tree_add_duplicate(addr->unique, addr);
1949 /* Now show its parents */
1953 fprintf(f, "\n <-- %s", p->address);
1958 /* Show router, and transport */
1960 fprintf(f, "router = %s, ", addr->router->name);
1961 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1962 addr->transport->name);
1964 /* Show any hosts that are set up by a router unless the transport
1965 is going to override them; fiddle a bit to get a nice format. */
1967 if (addr->host_list != NULL && addr->transport != NULL &&
1968 !addr->transport->overrides_hosts)
1973 for (h = addr->host_list; h != NULL; h = h->next)
1975 int len = Ustrlen(h->name);
1976 if (len > maxlen) maxlen = len;
1977 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1978 if (len > maxaddlen) maxaddlen = len;
1980 for (h = addr->host_list; h != NULL; h = h->next)
1982 int len = Ustrlen(h->name);
1983 fprintf(f, " host %s ", h->name);
1984 while (len++ < maxlen) fprintf(f, " ");
1985 if (h->address != NULL)
1987 fprintf(f, "[%s] ", h->address);
1988 len = Ustrlen(h->address);
1990 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1992 fprintf(f, "[unknown] ");
1996 while (len++ < maxaddlen) fprintf(f," ");
1997 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1998 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1999 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2006 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2007 the -bv or -bt case). */
2011 modify_variable(US"tls_bits", &tls_in.bits);
2012 modify_variable(US"tls_certificate_verified", &tls_in.certificate_verified);
2013 modify_variable(US"tls_cipher", &tls_in.cipher);
2014 modify_variable(US"tls_peerdn", &tls_in.peerdn);
2015 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
2016 modify_variable(US"tls_sni", &tls_in.sni);
2025 /*************************************************
2026 * Check headers for syntax errors *
2027 *************************************************/
2029 /* This function checks those header lines that contain addresses, and verifies
2030 that all the addresses therein are syntactially correct.
2033 msgptr where to put an error message
2040 verify_check_headers(uschar **msgptr)
2046 for (h = header_list; h != NULL && yield == OK; h = h->next)
2048 if (h->type != htype_from &&
2049 h->type != htype_reply_to &&
2050 h->type != htype_sender &&
2051 h->type != htype_to &&
2052 h->type != htype_cc &&
2053 h->type != htype_bcc)
2056 colon = Ustrchr(h->text, ':');
2058 while (isspace(*s)) s++;
2060 /* Loop for multiple addresses in the header, enabling group syntax. Note
2061 that we have to reset this after the header has been scanned. */
2063 parse_allow_group = TRUE;
2067 uschar *ss = parse_find_address_end(s, FALSE);
2068 uschar *recipient, *errmess;
2069 int terminator = *ss;
2070 int start, end, domain;
2072 /* Temporarily terminate the string at this point, and extract the
2073 operative address within, allowing group syntax. */
2076 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2079 /* Permit an unqualified address only if the message is local, or if the
2080 sending host is configured to be permitted to send them. */
2082 if (recipient != NULL && domain == 0)
2084 if (h->type == htype_from || h->type == htype_sender)
2086 if (!allow_unqualified_sender) recipient = NULL;
2090 if (!allow_unqualified_recipient) recipient = NULL;
2092 if (recipient == NULL) errmess = US"unqualified address not permitted";
2095 /* It's an error if no address could be extracted, except for the special
2096 case of an empty address. */
2098 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2100 uschar *verb = US"is";
2105 /* Arrange not to include any white space at the end in the
2106 error message or the header name. */
2108 while (t > s && isspace(t[-1])) t--;
2109 while (tt > h->text && isspace(tt[-1])) tt--;
2111 /* Add the address that failed to the error message, since in a
2112 header with very many addresses it is sometimes hard to spot
2113 which one is at fault. However, limit the amount of address to
2114 quote - cases have been seen where, for example, a missing double
2115 quote in a humungous To: header creates an "address" that is longer
2116 than string_sprintf can handle. */
2125 *msgptr = string_printing(
2126 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2127 errmess, tt - h->text, h->text, verb, len, s));
2130 break; /* Out of address loop */
2133 /* Advance to the next address */
2135 s = ss + (terminator? 1:0);
2136 while (isspace(*s)) s++;
2137 } /* Next address */
2139 parse_allow_group = FALSE;
2140 parse_found_group = FALSE;
2141 } /* Next header unless yield has been set FALSE */
2148 /*************************************************
2149 * Check for blind recipients *
2150 *************************************************/
2152 /* This function checks that every (envelope) recipient is mentioned in either
2153 the To: or Cc: header lines, thus detecting blind carbon copies.
2155 There are two ways of scanning that could be used: either scan the header lines
2156 and tick off the recipients, or scan the recipients and check the header lines.
2157 The original proposed patch did the former, but I have chosen to do the latter,
2158 because (a) it requires no memory and (b) will use fewer resources when there
2159 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2162 Returns: OK if there are no blind recipients
2163 FAIL if there is at least one blind recipient
2167 verify_check_notblind(void)
2170 for (i = 0; i < recipients_count; i++)
2174 uschar *address = recipients_list[i].address;
2176 for (h = header_list; !found && h != NULL; h = h->next)
2180 if (h->type != htype_to && h->type != htype_cc) continue;
2182 colon = Ustrchr(h->text, ':');
2184 while (isspace(*s)) s++;
2186 /* Loop for multiple addresses in the header, enabling group syntax. Note
2187 that we have to reset this after the header has been scanned. */
2189 parse_allow_group = TRUE;
2193 uschar *ss = parse_find_address_end(s, FALSE);
2194 uschar *recipient,*errmess;
2195 int terminator = *ss;
2196 int start, end, domain;
2198 /* Temporarily terminate the string at this point, and extract the
2199 operative address within, allowing group syntax. */
2202 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2205 /* If we found a valid recipient that has a domain, compare it with the
2206 envelope recipient. Local parts are compared case-sensitively, domains
2207 case-insensitively. By comparing from the start with length "domain", we
2208 include the "@" at the end, which ensures that we are comparing the whole
2209 local part of each address. */
2211 if (recipient != NULL && domain != 0)
2213 found = Ustrncmp(recipient, address, domain) == 0 &&
2214 strcmpic(recipient + domain, address + domain) == 0;
2218 /* Advance to the next address */
2220 s = ss + (terminator? 1:0);
2221 while (isspace(*s)) s++;
2222 } /* Next address */
2224 parse_allow_group = FALSE;
2225 parse_found_group = FALSE;
2226 } /* Next header (if found is false) */
2228 if (!found) return FAIL;
2229 } /* Next recipient */
2236 /*************************************************
2237 * Find if verified sender *
2238 *************************************************/
2240 /* Usually, just a single address is verified as the sender of the message.
2241 However, Exim can be made to verify other addresses as well (often related in
2242 some way), and this is useful in some environments. There may therefore be a
2243 chain of such addresses that have previously been tested. This function finds
2244 whether a given address is on the chain.
2246 Arguments: the address to be verified
2247 Returns: pointer to an address item, or NULL
2251 verify_checked_sender(uschar *sender)
2254 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2255 if (Ustrcmp(sender, addr->address) == 0) break;
2263 /*************************************************
2264 * Get valid header address *
2265 *************************************************/
2267 /* Scan the originator headers of the message, looking for an address that
2268 verifies successfully. RFC 822 says:
2270 o The "Sender" field mailbox should be sent notices of
2271 any problems in transport or delivery of the original
2272 messages. If there is no "Sender" field, then the
2273 "From" field mailbox should be used.
2275 o If the "Reply-To" field exists, then the reply should
2276 go to the addresses indicated in that field and not to
2277 the address(es) indicated in the "From" field.
2279 So we check a Sender field if there is one, else a Reply_to field, else a From
2280 field. As some strange messages may have more than one of these fields,
2281 especially if they are resent- fields, check all of them if there is more than
2285 user_msgptr points to where to put a user error message
2286 log_msgptr points to where to put a log error message
2287 callout timeout for callout check (passed to verify_address())
2288 callout_overall overall callout timeout (ditto)
2289 callout_connect connect callout timeout (ditto)
2290 se_mailfrom mailfrom for verify; NULL => ""
2291 pm_mailfrom sender for pm callout check (passed to verify_address())
2292 options callout options (passed to verify_address())
2293 verrno where to put the address basic_errno
2295 If log_msgptr is set to something without setting user_msgptr, the caller
2296 normally uses log_msgptr for both things.
2298 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2299 FAIL is given if no appropriate headers are found
2303 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2304 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2305 uschar *pm_mailfrom, int options, int *verrno)
2307 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2312 for (i = 0; i < 3 && !done; i++)
2315 for (h = header_list; h != NULL && !done; h = h->next)
2317 int terminator, new_ok;
2318 uschar *s, *ss, *endname;
2320 if (h->type != header_types[i]) continue;
2321 s = endname = Ustrchr(h->text, ':') + 1;
2323 /* Scan the addresses in the header, enabling group syntax. Note that we
2324 have to reset this after the header has been scanned. */
2326 parse_allow_group = TRUE;
2330 address_item *vaddr;
2332 while (isspace(*s) || *s == ',') s++;
2333 if (*s == 0) break; /* End of header */
2335 ss = parse_find_address_end(s, FALSE);
2337 /* The terminator is a comma or end of header, but there may be white
2338 space preceding it (including newline for the last address). Move back
2339 past any white space so we can check against any cached envelope sender
2340 address verifications. */
2342 while (isspace(ss[-1])) ss--;
2346 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2347 (int)(endname - h->text), h->text, s);
2349 /* See if we have already verified this address as an envelope sender,
2350 and if so, use the previous answer. */
2352 vaddr = verify_checked_sender(s);
2354 if (vaddr != NULL && /* Previously checked */
2355 (callout <= 0 || /* No callout needed; OR */
2356 vaddr->special_action > 256)) /* Callout was done */
2358 new_ok = vaddr->special_action & 255;
2359 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2360 *ss = terminator; /* Restore shortened string */
2363 /* Otherwise we run the verification now. We must restore the shortened
2364 string before running the verification, so the headers are correct, in
2365 case there is any rewriting. */
2369 int start, end, domain;
2370 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2375 /* If we found an empty address, just carry on with the next one, but
2376 kill the message. */
2378 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2385 /* If verification failed because of a syntax error, fail this
2386 function, and ensure that the failing address gets added to the error
2389 if (address == NULL)
2392 while (ss > s && isspace(ss[-1])) ss--;
2393 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2394 "scanning for sender: %s in \"%.*s\"",
2395 endname - h->text, h->text, *log_msgptr, ss - s, s);
2401 /* Else go ahead with the sender verification. But it isn't *the*
2402 sender of the message, so set vopt_fake_sender to stop sender_address
2403 being replaced after rewriting or qualification. */
2407 vaddr = deliver_make_addr(address, FALSE);
2408 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2409 callout, callout_overall, callout_connect, se_mailfrom,
2414 /* We now have the result, either newly found, or cached. If we are
2415 giving out error details, set a specific user error. This means that the
2416 last of these will be returned to the user if all three fail. We do not
2417 set a log message - the generic one below will be used. */
2421 *verrno = vaddr->basic_errno;
2422 if (smtp_return_error_details)
2424 *user_msgptr = string_sprintf("Rejected after DATA: "
2425 "could not verify \"%.*s\" header address\n%s: %s",
2426 endname - h->text, h->text, vaddr->address, vaddr->message);
2430 /* Success or defer */
2439 if (new_ok == DEFER) yield = DEFER;
2441 /* Move on to any more addresses in the header */
2444 } /* Next address */
2446 parse_allow_group = FALSE;
2447 parse_found_group = FALSE;
2448 } /* Next header, unless done */
2449 } /* Next header type unless done */
2451 if (yield == FAIL && *log_msgptr == NULL)
2452 *log_msgptr = US"there is no valid sender in any header line";
2454 if (yield == DEFER && *log_msgptr == NULL)
2455 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2463 /*************************************************
2464 * Get RFC 1413 identification *
2465 *************************************************/
2467 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2468 the timeout is set to zero, then the query is not done. There may also be lists
2469 of hosts and nets which are exempt. To guard against malefactors sending
2470 non-printing characters which could, for example, disrupt a message's headers,
2471 make sure the string consists of printing characters only.
2474 port the port to connect to; usually this is IDENT_PORT (113), but when
2475 running in the test harness with -bh a different value is used.
2479 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2483 verify_get_ident(int port)
2485 int sock, host_af, qlen;
2486 int received_sender_port, received_interface_port, n;
2488 uschar buffer[2048];
2490 /* Default is no ident. Check whether we want to do an ident check for this
2493 sender_ident = NULL;
2494 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2497 DEBUG(D_ident) debug_printf("doing ident callback\n");
2499 /* Set up a connection to the ident port of the remote host. Bind the local end
2500 to the incoming interface address. If the sender host address is an IPv6
2501 address, the incoming interface address will also be IPv6. */
2503 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2504 sock = ip_socket(SOCK_STREAM, host_af);
2505 if (sock < 0) return;
2507 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2509 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2514 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2517 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2519 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2520 sender_host_address);
2524 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2525 sender_host_address, strerror(errno));
2530 /* Construct and send the query. */
2532 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2533 qlen = Ustrlen(buffer);
2534 if (send(sock, buffer, qlen, 0) < 0)
2536 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2540 /* Read a response line. We put it into the rest of the buffer, using several
2541 recv() calls if necessary. */
2549 int size = sizeof(buffer) - (p - buffer);
2551 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2552 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2553 if (count <= 0) goto END_OFF; /* Read error or EOF */
2555 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2556 generous, and accept a plain \n terminator as well. The only illegal
2559 for (pp = p; pp < p + count; pp++)
2561 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2564 if (pp[-1] == '\r') pp--;
2566 goto GOT_DATA; /* Break out of both loops */
2570 /* Reached the end of the data without finding \n. Let the loop continue to
2571 read some more, if there is room. */
2578 /* We have received a line of data. Check it carefully. It must start with the
2579 same two port numbers that we sent, followed by data as defined by the RFC. For
2582 12345 , 25 : USERID : UNIX :root
2584 However, the amount of white space may be different to what we sent. In the
2585 "osname" field there may be several sub-fields, comma separated. The data we
2586 actually want to save follows the third colon. Some systems put leading spaces
2587 in it - we discard those. */
2589 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2590 &received_interface_port, &n) != 2 ||
2591 received_sender_port != sender_host_port ||
2592 received_interface_port != interface_port)
2595 p = buffer + qlen + n;
2596 while(isspace(*p)) p++;
2597 if (*p++ != ':') goto END_OFF;
2598 while(isspace(*p)) p++;
2599 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2601 while(isspace(*p)) p++;
2602 if (*p++ != ':') goto END_OFF;
2603 while (*p != 0 && *p != ':') p++;
2604 if (*p++ == 0) goto END_OFF;
2605 while(isspace(*p)) p++;
2606 if (*p == 0) goto END_OFF;
2608 /* The rest of the line is the data we want. We turn it into printing
2609 characters when we save it, so that it cannot mess up the format of any logging
2610 or Received: lines into which it gets inserted. We keep a maximum of 127
2613 sender_ident = string_printing(string_copyn(p, 127));
2614 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2624 /*************************************************
2625 * Match host to a single host-list item *
2626 *************************************************/
2628 /* This function compares a host (name or address) against a single item
2629 from a host list. The host name gets looked up if it is needed and is not
2630 already known. The function is called from verify_check_this_host() via
2631 match_check_list(), which is why most of its arguments are in a single block.
2634 arg the argument block (see below)
2635 ss the host-list item
2636 valueptr where to pass back looked up data, or NULL
2637 error for error message when returning ERROR
2640 host_name (a) the host name, or
2641 (b) NULL, implying use sender_host_name and
2642 sender_host_aliases, looking them up if required, or
2643 (c) the empty string, meaning that only IP address matches
2645 host_address the host address
2646 host_ipv4 the IPv4 address taken from an IPv6 one
2650 DEFER lookup deferred
2651 ERROR (a) failed to find the host name or IP address, or
2652 (b) unknown lookup type specified, or
2653 (c) host name encountered when only IP addresses are
2658 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2660 check_host_block *cb = (check_host_block *)arg;
2663 BOOL iplookup = FALSE;
2664 BOOL isquery = FALSE;
2665 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2670 /* Optimize for the special case when the pattern is "*". */
2672 if (*ss == '*' && ss[1] == 0) return OK;
2674 /* If the pattern is empty, it matches only in the case when there is no host -
2675 this can occur in ACL checking for SMTP input using the -bs option. In this
2676 situation, the host address is the empty string. */
2678 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2679 if (*ss == 0) return FAIL;
2681 /* If the pattern is precisely "@" then match against the primary host name,
2682 provided that host name matching is permitted; if it's "@[]" match against the
2683 local host's IP addresses. */
2689 if (isiponly) return ERROR;
2690 ss = primary_hostname;
2692 else if (Ustrcmp(ss, "@[]") == 0)
2694 ip_address_item *ip;
2695 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2696 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2701 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2702 a (possibly masked) comparision with the current IP address. */
2704 if (string_is_ip_address(ss, &maskoffset) != 0)
2705 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2707 /* The pattern is not an IP address. A common error that people make is to omit
2708 one component of an IPv4 address, either by accident, or believing that, for
2709 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,
2710 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2711 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2712 ancient specification.) To aid in debugging these cases, we give a specific
2713 error if the pattern contains only digits and dots or contains a slash preceded
2714 only by digits and dots (a slash at the start indicates a file name and of
2715 course slashes may be present in lookups, but not preceded only by digits and
2718 for (t = ss; isdigit(*t) || *t == '.'; t++);
2719 if (*t == 0 || (*t == '/' && t != ss))
2721 *error = US"malformed IPv4 address or address mask";
2725 /* See if there is a semicolon in the pattern */
2727 semicolon = Ustrchr(ss, ';');
2729 /* If we are doing an IP address only match, then all lookups must be IP
2730 address lookups, even if there is no "net-". */
2734 iplookup = semicolon != NULL;
2737 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2738 a lookup on a masked IP network, in textual form. We obey this code even if we
2739 have already set iplookup, so as to skip over the "net-" prefix and to set the
2740 mask length. The net- stuff really only applies to single-key lookups where the
2741 key is implicit. For query-style lookups the key is specified in the query.
2742 From release 4.30, the use of net- for query style is no longer needed, but we
2743 retain it for backward compatibility. */
2745 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2748 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2749 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2750 iplookup = (*t++ == '-');
2754 /* Do the IP address lookup if that is indeed what we have */
2762 uschar *filename, *key, *result;
2765 /* Find the search type */
2767 search_type = search_findtype(t, semicolon - t);
2769 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2770 search_error_message);
2772 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2773 is no file name, and the "key" is just the query. For query-style with a file
2774 name, we have to fish the file off the start of the query. For a single-key
2775 lookup, the key is the current IP address, masked appropriately, and
2776 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2777 dot separators instead of colons, except when the lookup type is "iplsearch".
2780 if (mac_islookup(search_type, lookup_absfilequery))
2782 filename = semicolon + 1;
2784 while (*key != 0 && !isspace(*key)) key++;
2785 filename = string_copyn(filename, key - filename);
2786 while (isspace(*key)) key++;
2788 else if (mac_islookup(search_type, lookup_querystyle))
2791 key = semicolon + 1;
2793 else /* Single-key style */
2795 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2797 insize = host_aton(cb->host_address, incoming);
2798 host_mask(insize, incoming, mlen);
2799 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2801 filename = semicolon + 1;
2804 /* Now do the actual lookup; note that there is no search_close() because
2805 of the caching arrangements. */
2807 handle = search_open(filename, search_type, 0, NULL, NULL);
2808 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2809 search_error_message);
2810 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2811 if (valueptr != NULL) *valueptr = result;
2812 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2815 /* The pattern is not an IP address or network reference of any kind. That is,
2816 it is a host name pattern. If this is an IP only match, there's an error in the
2821 *error = US"cannot match host name in match_ip list";
2825 /* Check the characters of the pattern to see if they comprise only letters,
2826 digits, full stops, and hyphens (the constituents of domain names). Allow
2827 underscores, as they are all too commonly found. Sigh. Also, if
2828 allow_utf8_domains is set, allow top-bit characters. */
2830 for (t = ss; *t != 0; t++)
2831 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2832 (!allow_utf8_domains || *t < 128)) break;
2834 /* If the pattern is a complete domain name, with no fancy characters, look up
2835 its IP address and match against that. Note that a multi-homed host will add
2836 items to the chain. */
2847 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2848 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2851 for (hh = &h; hh != NULL; hh = hh->next)
2853 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2857 if (rc == HOST_FIND_AGAIN) return DEFER;
2858 *error = string_sprintf("failed to find IP address for %s", ss);
2862 /* Almost all subsequent comparisons require the host name, and can be done
2863 using the general string matching function. When this function is called for
2864 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2865 must use sender_host_name and its aliases, looking them up if necessary. */
2867 if (cb->host_name != NULL) /* Explicit host name given */
2868 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2871 /* Host name not given; in principle we need the sender host name and its
2872 aliases. However, for query-style lookups, we do not need the name if the
2873 query does not contain $sender_host_name. From release 4.23, a reference to
2874 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2877 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2880 int partial, affixlen, starflags, id;
2883 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2886 if (id < 0) /* Unknown lookup type */
2888 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2889 search_error_message, ss);
2892 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2897 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2900 case DEFER: return DEFER;
2901 default: return FAIL;
2905 /* Not a query-style lookup; must ensure the host name is present, and then we
2906 do a check on the name and all its aliases. */
2908 if (sender_host_name == NULL)
2910 HDEBUG(D_host_lookup)
2911 debug_printf("sender host name required, to match against %s\n", ss);
2912 if (host_lookup_failed || host_name_lookup() != OK)
2914 *error = string_sprintf("failed to find host name for %s",
2915 sender_host_address);;
2918 host_build_sender_fullhost();
2921 /* Match on the sender host name, using the general matching function */
2923 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2927 case DEFER: return DEFER;
2930 /* If there are aliases, try matching on them. */
2932 aliases = sender_host_aliases;
2933 while (*aliases != NULL)
2935 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2938 case DEFER: return DEFER;
2947 /*************************************************
2948 * Check a specific host matches a host list *
2949 *************************************************/
2951 /* This function is passed a host list containing items in a number of
2952 different formats and the identity of a host. Its job is to determine whether
2953 the given host is in the set of hosts defined by the list. The host name is
2954 passed as a pointer so that it can be looked up if needed and not already
2955 known. This is commonly the case when called from verify_check_host() to check
2956 an incoming connection. When called from elsewhere the host name should usually
2959 This function is now just a front end to match_check_list(), which runs common
2960 code for scanning a list. We pass it the check_host() function to perform a
2964 listptr pointer to the host list
2965 cache_bits pointer to cache for named lists, or NULL
2966 host_name the host name or NULL, implying use sender_host_name and
2967 sender_host_aliases, looking them up if required
2968 host_address the IP address
2969 valueptr if not NULL, data from a lookup is passed back here
2971 Returns: OK if the host is in the defined set
2972 FAIL if the host is not in the defined set,
2973 DEFER if a data lookup deferred (not a host lookup)
2975 If the host name was needed in order to make a comparison, and could not be
2976 determined from the IP address, the result is FAIL unless the item
2977 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2980 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2981 uschar *host_name, uschar *host_address, uschar **valueptr)
2984 unsigned int *local_cache_bits = cache_bits;
2985 uschar *save_host_address = deliver_host_address;
2986 check_host_block cb;
2987 cb.host_name = host_name;
2988 cb.host_address = host_address;
2990 if (valueptr != NULL) *valueptr = NULL;
2992 /* If the host address starts off ::ffff: it is an IPv6 address in
2993 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2996 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2997 host_address + 7 : host_address;
2999 /* During the running of the check, put the IP address into $host_address. In
3000 the case of calls from the smtp transport, it will already be there. However,
3001 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3002 the safe side, any existing setting is preserved, though as I write this
3003 (November 2004) I can't see any cases where it is actually needed. */
3005 deliver_host_address = host_address;
3006 rc = match_check_list(
3007 listptr, /* the list */
3008 0, /* separator character */
3009 &hostlist_anchor, /* anchor pointer */
3010 &local_cache_bits, /* cache pointer */
3011 check_host, /* function for testing */
3012 &cb, /* argument for function */
3013 MCL_HOST, /* type of check */
3014 (host_address == sender_host_address)?
3015 US"host" : host_address, /* text for debugging */
3016 valueptr); /* where to pass back data */
3017 deliver_host_address = save_host_address;
3024 /*************************************************
3025 * Check the remote host matches a list *
3026 *************************************************/
3028 /* This is a front end to verify_check_this_host(), created because checking
3029 the remote host is a common occurrence. With luck, a good compiler will spot
3030 the tail recursion and optimize it. If there's no host address, this is
3031 command-line SMTP input - check against an empty string for the address.
3034 listptr pointer to the host list
3036 Returns: the yield of verify_check_this_host(),
3037 i.e. OK, FAIL, or DEFER
3041 verify_check_host(uschar **listptr)
3043 return verify_check_this_host(listptr, sender_host_cache, NULL,
3044 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3051 /*************************************************
3052 * Invert an IP address *
3053 *************************************************/
3055 /* Originally just used for DNS xBL lists, now also used for the
3056 reverse_ip expansion operator.
3059 buffer where to put the answer
3060 address the address to invert
3064 invert_address(uschar *buffer, uschar *address)
3067 uschar *bptr = buffer;
3069 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3070 to the IPv4 part only. */
3072 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3074 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3077 if (host_aton(address, bin) == 1)
3081 for (i = 0; i < 4; i++)
3083 sprintf(CS bptr, "%d.", x & 255);
3084 while (*bptr) bptr++;
3089 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3090 in any DNS black lists, and the format in which they will be looked up is
3091 unknown. This is just a guess. */
3097 for (j = 3; j >= 0; j--)
3100 for (i = 0; i < 8; i++)
3102 sprintf(CS bptr, "%x.", x & 15);
3103 while (*bptr) bptr++;
3110 /* Remove trailing period -- this is needed so that both arbitrary
3111 dnsbl keydomains and inverted addresses may be combined with the
3112 same format string, "%s.%s" */
3119 /*************************************************
3120 * Perform a single dnsbl lookup *
3121 *************************************************/
3123 /* This function is called from verify_check_dnsbl() below. It is also called
3124 recursively from within itself when domain and domain_txt are different
3125 pointers, in order to get the TXT record from the alternate domain.
3128 domain the outer dnsbl domain
3129 domain_txt alternate domain to lookup TXT record on success; when the
3130 same domain is to be used, domain_txt == domain (that is,
3131 the pointers must be identical, not just the text)
3132 keydomain the current keydomain (for debug message)
3133 prepend subdomain to lookup (like keydomain, but
3134 reversed if IP address)
3135 iplist the list of matching IP addresses, or NULL for "any"
3136 bitmask true if bitmask matching is wanted
3137 match_type condition for 'succeed' result
3138 0 => Any RR in iplist (=)
3139 1 => No RR in iplist (!=)
3140 2 => All RRs in iplist (==)
3141 3 => Some RRs not in iplist (!==)
3142 the two bits are defined as MT_NOT and MT_ALL
3143 defer_return what to return for a defer
3145 Returns: OK if lookup succeeded
3150 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3151 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3157 dnsbl_cache_block *cb;
3158 int old_pool = store_pool;
3159 uschar query[256]; /* DNS domain max length */
3161 /* Construct the specific query domainname */
3163 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3165 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3166 "(ignored): %s...", query);
3170 /* Look for this query in the cache. */
3172 t = tree_search(dnsbl_cache, query);
3174 /* If not cached from a previous lookup, we must do a DNS lookup, and
3175 cache the result in permanent memory. */
3179 store_pool = POOL_PERM;
3181 /* Set up a tree entry to cache the lookup */
3183 t = store_get(sizeof(tree_node) + Ustrlen(query));
3184 Ustrcpy(t->name, query);
3185 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3186 (void)tree_insertnode(&dnsbl_cache, t);
3188 /* Do the DNS loopup . */
3190 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3191 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3192 cb->text_set = FALSE;
3196 /* If the lookup succeeded, cache the RHS address. The code allows for
3197 more than one address - this was for complete generality and the possible
3198 use of A6 records. However, A6 records have been reduced to experimental
3199 status (August 2001) and may die out. So they may never get used at all,
3200 let alone in dnsbl records. However, leave the code here, just in case.
3202 Quite apart from one A6 RR generating multiple addresses, there are DNS
3203 lists that return more than one A record, so we must handle multiple
3204 addresses generated in that way as well. */
3206 if (cb->rc == DNS_SUCCEED)
3209 dns_address **addrp = &(cb->rhs);
3210 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3212 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3214 if (rr->type == T_A)
3216 dns_address *da = dns_address_from_rr(&dnsa, rr);
3220 while (da->next != NULL) da = da->next;
3221 addrp = &(da->next);
3226 /* If we didn't find any A records, change the return code. This can
3227 happen when there is a CNAME record but there are no A records for what
3230 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3233 store_pool = old_pool;
3236 /* Previous lookup was cached */
3240 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3244 /* We now have the result of the DNS lookup, either newly done, or cached
3245 from a previous call. If the lookup succeeded, check against the address
3246 list if there is one. This may be a positive equality list (introduced by
3247 "="), a negative equality list (introduced by "!="), a positive bitmask
3248 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3250 if (cb->rc == DNS_SUCCEED)
3252 dns_address *da = NULL;
3253 uschar *addlist = cb->rhs->address;
3255 /* For A and AAAA records, there may be multiple addresses from multiple
3256 records. For A6 records (currently not expected to be used) there may be
3257 multiple addresses from a single record. */
3259 for (da = cb->rhs->next; da != NULL; da = da->next)
3260 addlist = string_sprintf("%s, %s", addlist, da->address);
3262 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3265 /* Address list check; this can be either for equality, or via a bitmask.
3266 In the latter case, all the bits must match. */
3270 for (da = cb->rhs; da != NULL; da = da->next)
3274 uschar *ptr = iplist;
3277 /* Handle exact matching */
3281 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3283 if (Ustrcmp(CS da->address, ip) == 0) break;
3287 /* Handle bitmask matching */
3294 /* At present, all known DNS blocking lists use A records, with
3295 IPv4 addresses on the RHS encoding the information they return. I
3296 wonder if this will linger on as the last vestige of IPv4 when IPv6
3297 is ubiquitous? Anyway, for now we use paranoia code to completely
3298 ignore IPv6 addresses. The default mask is 0, which always matches.
3299 We change this only for IPv4 addresses in the list. */
3301 if (host_aton(da->address, address) == 1) mask = address[0];
3303 /* Scan the returned addresses, skipping any that are IPv6 */
3305 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3307 if (host_aton(ip, address) != 1) continue;
3308 if ((address[0] & mask) == address[0]) break;
3314 (a) An IP address in an any ('=') list matched, or
3315 (b) No IP address in an all ('==') list matched
3317 then we're done searching. */
3319 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3322 /* If da == NULL, either
3324 (a) No IP address in an any ('=') list matched, or
3325 (b) An IP address in an all ('==') list didn't match
3327 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3330 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3338 res = US"was no match";
3341 res = US"was an exclude match";
3344 res = US"was an IP address that did not match";
3347 res = US"were no IP addresses that did not match";
3350 debug_printf("=> but we are not accepting this block class because\n");
3351 debug_printf("=> there %s for %s%c%s\n",
3353 ((match_type & MT_ALL) == 0)? "" : "=",
3354 bitmask? '&' : '=', iplist);
3360 /* Either there was no IP list, or the record matched, implying that the
3361 domain is on the list. We now want to find a corresponding TXT record. If an
3362 alternate domain is specified for the TXT record, call this function
3363 recursively to look that up; this has the side effect of re-checking that
3364 there is indeed an A record at the alternate domain. */
3366 if (domain_txt != domain)
3367 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3368 FALSE, match_type, defer_return);
3370 /* If there is no alternate domain, look up a TXT record in the main domain
3371 if it has not previously been cached. */
3375 cb->text_set = TRUE;
3376 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3379 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3381 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3382 if (rr->type == T_TXT) break;
3385 int len = (rr->data)[0];
3386 if (len > 511) len = 127;
3387 store_pool = POOL_PERM;
3388 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3389 store_pool = old_pool;
3394 dnslist_value = addlist;
3395 dnslist_text = cb->text;
3399 /* There was a problem with the DNS lookup */
3401 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3403 log_write(L_dnslist_defer, LOG_MAIN,
3404 "DNS list lookup defer (probably timeout) for %s: %s", query,
3405 (defer_return == OK)? US"assumed in list" :
3406 (defer_return == FAIL)? US"assumed not in list" :
3407 US"returned DEFER");
3408 return defer_return;
3411 /* No entry was found in the DNS; continue for next domain */
3415 debug_printf("DNS lookup for %s failed\n", query);
3416 debug_printf("=> that means %s is not listed at %s\n",
3426 /*************************************************
3427 * Check host against DNS black lists *
3428 *************************************************/
3430 /* This function runs checks against a list of DNS black lists, until one
3431 matches. Each item on the list can be of the form
3433 domain=ip-address/key
3435 The domain is the right-most domain that is used for the query, for example,
3436 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3437 if the DNS lookup returns a matching IP address. Several addresses may be
3438 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3440 If no key is given, what is looked up in the domain is the inverted IP address
3441 of the current client host. If a key is given, it is used to construct the
3442 domain for the lookup. For example:
3444 dsn.rfc-ignorant.org/$sender_address_domain
3446 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3447 then we check for a TXT record for an error message, and if found, save its
3448 value in $dnslist_text. We also cache everything in a tree, to optimize
3451 The TXT record is normally looked up in the same domain as the A record, but
3452 when many lists are combined in a single DNS domain, this will not be a very
3453 specific message. It is possible to specify a different domain for looking up
3454 TXT records; this is given before the main domain, comma-separated. For
3457 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3458 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3460 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3462 Note: an address for testing RBL is 192.203.178.39
3463 Note: an address for testing DUL is 192.203.178.4
3464 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3467 listptr the domain/address/data list
3469 Returns: OK successful lookup (i.e. the address is on the list), or
3470 lookup deferred after +include_unknown
3471 FAIL name not found, or no data found for the given type, or
3472 lookup deferred after +exclude_unknown (default)
3473 DEFER lookup failure, if +defer_unknown was set
3477 verify_check_dnsbl(uschar **listptr)
3480 int defer_return = FAIL;
3481 uschar *list = *listptr;
3484 uschar buffer[1024];
3485 uschar revadd[128]; /* Long enough for IPv6 address */
3487 /* Indicate that the inverted IP address is not yet set up */
3491 /* In case this is the first time the DNS resolver is being used. */
3493 dns_init(FALSE, FALSE);
3495 /* Loop through all the domains supplied, until something matches */
3497 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3500 BOOL bitmask = FALSE;
3507 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3509 /* Deal with special values that change the behaviour on defer */
3511 if (domain[0] == '+')
3513 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3514 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3515 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3517 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3522 /* See if there's explicit data to be looked up */
3524 key = Ustrchr(domain, '/');
3525 if (key != NULL) *key++ = 0;
3527 /* See if there's a list of addresses supplied after the domain name. This is
3528 introduced by an = or a & character; if preceded by = we require all matches
3529 and if preceded by ! we invert the result. */
3531 iplist = Ustrchr(domain, '=');
3535 iplist = Ustrchr(domain, '&');
3538 if (iplist != NULL) /* Found either = or & */
3540 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3542 match_type |= MT_NOT;
3546 *iplist++ = 0; /* Terminate domain, move on */
3548 /* If we found = (bitmask == FALSE), check for == or =& */
3550 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3552 bitmask = *iplist++ == '&';
3553 match_type |= MT_ALL;
3557 /* If there is a comma in the domain, it indicates that a second domain for
3558 looking up TXT records is provided, before the main domain. Otherwise we must
3559 set domain_txt == domain. */
3561 domain_txt = domain;
3562 comma = Ustrchr(domain, ',');
3569 /* Check that what we have left is a sensible domain name. There is no reason
3570 why these domains should in fact use the same syntax as hosts and email
3571 domains, but in practice they seem to. However, there is little point in
3572 actually causing an error here, because that would no doubt hold up incoming
3573 mail. Instead, I'll just log it. */
3575 for (s = domain; *s != 0; s++)
3577 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3579 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3580 "strange characters - is this right?", domain);
3585 /* Check the alternate domain if present */
3587 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3589 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3591 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3592 "strange characters - is this right?", domain_txt);
3597 /* If there is no key string, construct the query by adding the domain name
3598 onto the inverted host address, and perform a single DNS lookup. */
3602 if (sender_host_address == NULL) return FAIL; /* can never match */
3603 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3604 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3605 iplist, bitmask, match_type, defer_return);
3608 dnslist_domain = string_copy(domain_txt);
3609 dnslist_matched = string_copy(sender_host_address);
3610 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3611 sender_host_address, dnslist_domain);
3613 if (rc != FAIL) return rc; /* OK or DEFER */
3616 /* If there is a key string, it can be a list of domains or IP addresses to
3617 be concatenated with the main domain. */
3624 uschar keybuffer[256];
3625 uschar keyrevadd[128];
3627 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3628 sizeof(keybuffer))) != NULL)
3630 uschar *prepend = keydomain;
3632 if (string_is_ip_address(keydomain, NULL) != 0)
3634 invert_address(keyrevadd, keydomain);
3635 prepend = keyrevadd;
3638 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3639 bitmask, match_type, defer_return);
3643 dnslist_domain = string_copy(domain_txt);
3644 dnslist_matched = string_copy(keydomain);
3645 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3646 keydomain, dnslist_domain);
3650 /* If the lookup deferred, remember this fact. We keep trying the rest
3651 of the list to see if we get a useful result, and if we don't, we return
3652 DEFER at the end. */
3654 if (rc == DEFER) defer = TRUE;
3655 } /* continue with next keystring domain/address */
3657 if (defer) return DEFER;
3659 } /* continue with next dnsdb outer domain */
3664 /* End of verify.c */