1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
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,
645 ob->tls_verify_hosts, ob->tls_try_verify_hosts);
647 /* TLS negotiation failed; give an error. Try in clear on a new connection,
648 if the options permit it for this host. */
651 if (rc == DEFER && ob->tls_tempfail_tryclear && !smtps &&
652 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
653 host->address, NULL) != OK)
655 (void)close(inblock.sock);
656 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
657 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
659 goto tls_retry_connection;
661 /*save_errno = ERRNO_TLSFAILURE;*/
662 /*message = US"failure while setting up TLS session";*/
668 /* TLS session is set up. Copy info for logging. */
669 addr->cipher = tls_out.cipher;
670 addr->peerdn = tls_out.peerdn;
672 /* For SMTPS we need to wait for the initial OK response, then do HELO. */
674 goto smtps_redo_greeting;
676 /* For STARTTLS we need to redo EHLO */
681 /* If the host is required to use a secure channel, ensure that we have one. */
682 if (tls_out.active < 0)
683 if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
684 host->address, NULL) == OK)
686 /*save_errno = ERRNO_TLSREQUIRED;*/
687 log_write(0, LOG_MAIN, "a TLS session is required for %s [%s], but %s",
688 host->name, host->address,
689 tls_offered? "an attempt to start TLS failed" : "the server did not offer TLS support");
694 #endif /*SUPPORT_TLS*/
696 done = TRUE; /* so far so good; have response to HELO */
698 /*XXX the EHLO response would be analyzed here for IGNOREQUOTA, SIZE, PIPELINING */
700 /* For now, transport_filter by cutthrough-delivery is not supported */
701 /* Need proper integration with the proper transport mechanism. */
702 if (cutthrough_delivery)
704 if (addr->transport->filter_command)
706 cutthrough_delivery= FALSE;
707 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
712 cutthrough_delivery= FALSE;
713 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
722 /* Clear down of the TLS, SMTP and TCP layers on error is handled below. */
725 /* Failure to accept HELO is cached; this blocks the whole domain for all
726 senders. I/O errors and defer responses are not cached. */
730 *failure_ptr = US"mail"; /* At or before MAIL */
731 if (errno == 0 && responsebuffer[0] == '5')
733 setflag(addr, af_verify_nsfail);
734 new_domain_record.result = ccache_reject;
738 /* If we haven't authenticated, but are required to, give up. */
741 else done = smtp_auth(responsebuffer, sizeof(responsebuffer),
742 addr, host, ob, esmtp, &inblock, &outblock) == OK &&
744 /* Copy AUTH info for logging */
745 ( (addr->authenticator = client_authenticator),
746 (addr->auth_id = client_authenticated_id),
748 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
749 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
752 ( (addr->auth_sndr = client_authenticated_sender),
754 /* Send the MAIL command */
755 (smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>%s\r\n",
756 from_address, responsebuffer) >= 0)
759 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
762 /* If the host does not accept MAIL FROM:<>, arrange to cache this
763 information, but again, don't record anything for an I/O error or a defer. Do
764 not cache rejections of MAIL when a non-empty sender has been used, because
765 that blocks the whole domain for all senders. */
769 *failure_ptr = US"mail"; /* At or before MAIL */
770 if (errno == 0 && responsebuffer[0] == '5')
772 setflag(addr, af_verify_nsfail);
773 if (from_address[0] == 0)
774 new_domain_record.result = ccache_reject_mfnull;
778 /* Otherwise, proceed to check a "random" address (if required), then the
779 given address, and the postmaster address (if required). Between each check,
780 issue RSET, because some servers accept only one recipient after MAIL
783 Before doing this, set the result in the domain cache record to "accept",
784 unless its previous value was ccache_reject_mfnull. In that case, the domain
785 rejects MAIL FROM:<> and we want to continue to remember that. When that is
786 the case, we have got here only in the case of a recipient verification with
787 a non-null sender. */
791 new_domain_record.result =
792 (old_domain_cache_result == ccache_reject_mfnull)?
793 ccache_reject_mfnull: ccache_accept;
795 /* Do the random local part check first */
797 if (random_local_part != NULL)
799 uschar randombuffer[1024];
801 smtp_write_command(&outblock, FALSE,
802 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
803 addr->domain) >= 0 &&
804 smtp_read_response(&inblock, randombuffer,
805 sizeof(randombuffer), '2', callout);
807 /* Remember when we last did a random test */
809 new_domain_record.random_stamp = time(NULL);
811 /* If accepted, we aren't going to do any further tests below. */
815 new_domain_record.random_result = ccache_accept;
818 /* Otherwise, cache a real negative response, and get back to the right
819 state to send RCPT. Unless there's some problem such as a dropped
820 connection, we expect to succeed, because the commands succeeded above. */
824 if (randombuffer[0] == '5')
825 new_domain_record.random_result = ccache_reject;
828 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
829 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
832 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
833 from_address) >= 0 &&
834 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
837 else done = FALSE; /* Some timeout/connection problem */
840 /* If the host is accepting all local parts, as determined by the "random"
841 check, we don't need to waste time doing any further checking. */
843 if (new_domain_record.random_result != ccache_accept && done)
845 /* Get the rcpt_include_affixes flag from the transport if there is one,
846 but assume FALSE if there is not. */
849 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
850 transport_rcpt_address(addr,
851 (addr->transport == NULL)? FALSE :
852 addr->transport->rcpt_include_affixes)) >= 0 &&
853 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
857 new_address_record.result = ccache_accept;
858 else if (errno == 0 && responsebuffer[0] == '5')
860 *failure_ptr = US"recipient";
861 new_address_record.result = ccache_reject;
864 /* Do postmaster check if requested; if a full check is required, we
865 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
867 if (done && pm_mailfrom != NULL)
869 /*XXX not suitable for cutthrough - sequencing problems */
870 cutthrough_delivery= FALSE;
871 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
874 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
875 smtp_read_response(&inblock, responsebuffer,
876 sizeof(responsebuffer), '2', callout) &&
878 smtp_write_command(&outblock, FALSE,
879 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
880 smtp_read_response(&inblock, responsebuffer,
881 sizeof(responsebuffer), '2', callout) &&
883 /* First try using the current domain */
886 smtp_write_command(&outblock, FALSE,
887 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
888 smtp_read_response(&inblock, responsebuffer,
889 sizeof(responsebuffer), '2', callout)
894 /* If that doesn't work, and a full check is requested,
895 try without the domain. */
898 (options & vopt_callout_fullpm) != 0 &&
899 smtp_write_command(&outblock, FALSE,
900 "RCPT TO:<postmaster>\r\n") >= 0 &&
901 smtp_read_response(&inblock, responsebuffer,
902 sizeof(responsebuffer), '2', callout)
905 /* Sort out the cache record */
907 new_domain_record.postmaster_stamp = time(NULL);
910 new_domain_record.postmaster_result = ccache_accept;
911 else if (errno == 0 && responsebuffer[0] == '5')
913 *failure_ptr = US"postmaster";
914 setflag(addr, af_verify_pmfail);
915 new_domain_record.postmaster_result = ccache_reject;
918 } /* Random not accepted */
919 } /* MAIL FROM: accepted */
921 /* For any failure of the main check, other than a negative response, we just
922 close the connection and carry on. We can identify a negative response by the
923 fact that errno is zero. For I/O errors it will be non-zero
925 Set up different error texts for logging and for sending back to the caller
926 as an SMTP response. Log in all cases, using a one-line format. For sender
927 callouts, give a full response to the caller, but for recipient callouts,
928 don't give the IP address because this may be an internal host whose identity
929 is not to be widely broadcast. */
933 if (errno == ETIMEDOUT)
935 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
940 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
943 string_sprintf("response to \"%s\" from %s [%s] was: %s",
944 big_buffer, host->name, host->address,
945 string_printing(responsebuffer));
947 addr->user_message = is_recipient?
948 string_sprintf("Callout verification failed:\n%s", responsebuffer)
950 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
951 host->address, big_buffer, responsebuffer);
953 /* Hard rejection ends the process */
955 if (responsebuffer[0] == '5') /* Address rejected */
963 /* End the SMTP conversation and close the connection. */
965 /* Cutthrough - on a successfull connect and recipient-verify with use-sender
966 and we have no cutthrough conn so far
967 here is where we want to leave the conn open */
968 if ( cutthrough_delivery
971 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
972 && !random_local_part
977 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
978 cutthrough_addr = *addr; /* Save the address_item for later logging */
979 cutthrough_addr.next = NULL;
980 cutthrough_addr.host_used = store_get(sizeof(host_item));
981 cutthrough_addr.host_used->name = host->name;
982 cutthrough_addr.host_used->address = host->address;
983 cutthrough_addr.host_used->port = port;
985 *(cutthrough_addr.parent = store_get(sizeof(address_item)))= *addr->parent;
986 ctblock.buffer = ctbuffer;
987 ctblock.buffersize = sizeof(ctbuffer);
988 ctblock.ptr = ctbuffer;
989 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
990 ctblock.sock = cutthrough_fd;
994 /* Ensure no cutthrough on multiple address verifies */
995 if (options & vopt_callout_recipsender)
996 cancel_cutthrough_connection("multiple verify calls");
997 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1000 tls_close(FALSE, TRUE);
1002 (void)close(inblock.sock);
1005 } /* Loop through all hosts, while !done */
1008 /* If we get here with done == TRUE, a successful callout happened, and yield
1009 will be set OK or FAIL according to the response to the RCPT command.
1010 Otherwise, we looped through the hosts but couldn't complete the business.
1011 However, there may be domain-specific information to cache in both cases.
1013 The value of the result field in the new_domain record is ccache_unknown if
1014 there was an error before or with MAIL FROM:, and errno was not zero,
1015 implying some kind of I/O error. We don't want to write the cache in that case.
1016 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
1018 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
1020 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
1023 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
1027 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
1028 (int)sizeof(dbdata_callout_cache));
1029 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
1030 " result=%d postmaster=%d random=%d\n",
1031 new_domain_record.result,
1032 new_domain_record.postmaster_result,
1033 new_domain_record.random_result);
1037 /* If a definite result was obtained for the callout, cache it unless caching
1042 if (!callout_no_cache && new_address_record.result != ccache_unknown)
1044 if (dbm_file == NULL)
1045 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
1046 if (dbm_file == NULL)
1048 HDEBUG(D_verify) debug_printf("no callout cache available\n");
1052 (void)dbfn_write(dbm_file, address_key, &new_address_record,
1053 (int)sizeof(dbdata_callout_cache_address));
1054 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
1055 (new_address_record.result == ccache_accept)? "positive" : "negative");
1060 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1061 temporary error. If there was only one host, and a response was received, leave
1062 it alone if supplying details. Otherwise, give a generic response. */
1066 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
1067 is_recipient? "recipient" : "sender");
1070 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
1072 addr->user_message = (!smtp_return_error_details)? dullmsg :
1073 string_sprintf("%s for <%s>.\n"
1074 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1075 "they may be permanently unreachable from this server. In the latter case,\n%s",
1076 dullmsg, addr->address,
1078 "the address will never be accepted."
1080 "you need to change the address or create an MX record for its domain\n"
1081 "if it is supposed to be generally accessible from the Internet.\n"
1082 "Talk to your mail administrator for details.");
1084 /* Force a specific error code */
1086 addr->basic_errno = ERRNO_CALLOUTDEFER;
1089 /* Come here from within the cache-reading code on fast-track exit. */
1092 if (dbm_file != NULL) dbfn_close(dbm_file);
1098 /* Called after recipient-acl to get a cutthrough connection open when
1099 one was requested and a recipient-verify wasn't subsequently done.
1102 open_cutthrough_connection( address_item * addr )
1106 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1107 /* We must use a copy of the address for verification, because it might
1111 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
1112 (void) verify_address(&addr2, NULL,
1113 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1114 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1116 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1122 /* Send given number of bytes from the buffer */
1124 cutthrough_send(int n)
1126 if(cutthrough_fd < 0)
1131 (tls_out.active == cutthrough_fd) ? tls_write(FALSE, ctblock.buffer, n) :
1133 send(cutthrough_fd, ctblock.buffer, n, 0) > 0
1136 transport_count += n;
1137 ctblock.ptr= ctblock.buffer;
1141 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1148 _cutthrough_puts(uschar * cp, int n)
1152 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1153 if(!cutthrough_send(ctblock.buffersize))
1156 *ctblock.ptr++ = *cp++;
1161 /* Buffered output of counted data block. Return boolean success */
1163 cutthrough_puts(uschar * cp, int n)
1165 if (cutthrough_fd < 0) return TRUE;
1166 if (_cutthrough_puts(cp, n)) return TRUE;
1167 cancel_cutthrough_connection("transmit failed");
1173 _cutthrough_flush_send( void )
1175 int n= ctblock.ptr-ctblock.buffer;
1178 if(!cutthrough_send(n))
1184 /* Send out any bufferred output. Return boolean success. */
1186 cutthrough_flush_send( void )
1188 if (_cutthrough_flush_send()) return TRUE;
1189 cancel_cutthrough_connection("transmit failed");
1195 cutthrough_put_nl( void )
1197 return cutthrough_puts(US"\r\n", 2);
1201 /* Get and check response from cutthrough target */
1203 cutthrough_response(char expect, uschar ** copy)
1205 smtp_inblock inblock;
1206 uschar inbuffer[4096];
1207 uschar responsebuffer[4096];
1209 inblock.buffer = inbuffer;
1210 inblock.buffersize = sizeof(inbuffer);
1211 inblock.ptr = inbuffer;
1212 inblock.ptrend = inbuffer;
1213 inblock.sock = cutthrough_fd;
1214 /* this relies on (inblock.sock == tls_out.active) */
1215 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
1216 cancel_cutthrough_connection("target timeout on read");
1221 *copy= cp= string_copy(responsebuffer);
1222 /* Trim the trailing end of line */
1223 cp += Ustrlen(responsebuffer);
1224 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1225 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1228 return responsebuffer[0];
1232 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1234 cutthrough_predata( void )
1236 if(cutthrough_fd < 0)
1239 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1240 cutthrough_puts(US"DATA\r\n", 6);
1241 cutthrough_flush_send();
1243 /* Assume nothing buffered. If it was it gets ignored. */
1244 return cutthrough_response('3', NULL) == '3';
1248 /* fd and use_crlf args only to match write_chunk() */
1250 cutthrough_write_chunk(int fd, uschar * s, int len, BOOL use_crlf)
1253 while(s && (s2 = Ustrchr(s, '\n')))
1255 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1263 /* Buffered send of headers. Return success boolean. */
1264 /* Expands newlines to wire format (CR,NL). */
1265 /* Also sends header-terminating blank line. */
1267 cutthrough_headers_send( void )
1269 if(cutthrough_fd < 0)
1272 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1273 but having a separate buffered-output function (for now)
1275 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1277 if (!transport_headers_send(&cutthrough_addr, cutthrough_fd,
1278 cutthrough_addr.transport->add_headers, cutthrough_addr.transport->remove_headers,
1279 &cutthrough_write_chunk, TRUE,
1280 cutthrough_addr.transport->rewrite_rules, cutthrough_addr.transport->rewrite_existflags))
1283 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1289 close_cutthrough_connection( const char * why )
1291 if(cutthrough_fd >= 0)
1293 /* We could be sending this after a bunch of data, but that is ok as
1294 the only way to cancel the transfer in dataphase is to drop the tcp
1295 conn before the final dot.
1297 ctblock.ptr = ctbuffer;
1298 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1299 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1300 _cutthrough_flush_send();
1301 /* No wait for response */
1304 tls_close(FALSE, TRUE);
1306 (void)close(cutthrough_fd);
1308 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1310 ctblock.ptr = ctbuffer;
1314 cancel_cutthrough_connection( const char * why )
1316 close_cutthrough_connection(why);
1317 cutthrough_delivery= FALSE;
1323 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1324 Log an OK response as a transmission.
1325 Close the connection.
1326 Return smtp response-class digit.
1329 cutthrough_finaldot( void )
1331 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1333 /* Assume data finshed with new-line */
1334 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl() || !cutthrough_flush_send())
1335 return cutthrough_addr.message;
1337 switch(cutthrough_response('2', &cutthrough_addr.message))
1340 delivery_log(LOG_MAIN, &cutthrough_addr, (int)'>', NULL);
1341 close_cutthrough_connection("delivered");
1345 delivery_log(LOG_MAIN, &cutthrough_addr, 0, US"tmp-reject from cutthrough after DATA:");
1349 delivery_log(LOG_MAIN|LOG_REJECT, &cutthrough_addr, 0, US"rejected after DATA:");
1355 return cutthrough_addr.message;
1360 /*************************************************
1361 * Copy error to toplevel address *
1362 *************************************************/
1364 /* This function is used when a verify fails or defers, to ensure that the
1365 failure or defer information is in the original toplevel address. This applies
1366 when an address is redirected to a single new address, and the failure or
1367 deferral happens to the child address.
1370 vaddr the verify address item
1371 addr the final address item
1374 Returns: the value of YIELD
1378 copy_error(address_item *vaddr, address_item *addr, int yield)
1382 vaddr->message = addr->message;
1383 vaddr->user_message = addr->user_message;
1384 vaddr->basic_errno = addr->basic_errno;
1385 vaddr->more_errno = addr->more_errno;
1386 vaddr->p.address_data = addr->p.address_data;
1387 copyflag(vaddr, addr, af_pass_message);
1395 /**************************************************
1396 * printf that automatically handles TLS if needed *
1397 ***************************************************/
1399 /* This function is used by verify_address() as a substitute for all fprintf()
1400 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1401 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1402 that assumes that we always use the smtp_out FILE* when not using TLS or the
1403 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1404 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1408 f the candidate FILE* to write to
1409 format format string
1410 ... optional arguments
1416 static void PRINTF_FUNCTION(2,3)
1417 respond_printf(FILE *f, const char *format, ...)
1421 va_start(ap, format);
1422 if (smtp_out && (f == smtp_out))
1423 smtp_vprintf(format, ap);
1425 vfprintf(f, format, ap);
1431 /*************************************************
1432 * Verify an email address *
1433 *************************************************/
1435 /* This function is used both for verification (-bv and at other times) and
1436 address testing (-bt), which is indicated by address_test_mode being set.
1439 vaddr contains the address to verify; the next field in this block
1441 f if not NULL, write the result to this file
1442 options various option bits:
1443 vopt_fake_sender => this sender verify is not for the real
1444 sender (it was verify=sender=xxxx or an address from a
1445 header line) - rewriting must not change sender_address
1446 vopt_is_recipient => this is a recipient address, otherwise
1447 it's a sender address - this affects qualification and
1448 rewriting and messages from callouts
1449 vopt_qualify => qualify an unqualified address; else error
1450 vopt_expn => called from SMTP EXPN command
1451 vopt_success_on_redirect => when a new address is generated
1452 the verification instantly succeeds
1454 These ones are used by do_callout() -- the options variable
1457 vopt_callout_fullpm => if postmaster check, do full one
1458 vopt_callout_no_cache => don't use callout cache
1459 vopt_callout_random => do the "random" thing
1460 vopt_callout_recipsender => use real sender for recipient
1461 vopt_callout_recippmaster => use postmaster for recipient
1463 callout if > 0, specifies that callout is required, and gives timeout
1464 for individual commands
1465 callout_overall if > 0, gives overall timeout for the callout function;
1466 if < 0, a default is used (see do_callout())
1467 callout_connect the connection timeout for callouts
1468 se_mailfrom when callout is requested to verify a sender, use this
1469 in MAIL FROM; NULL => ""
1470 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1471 thing and use this as the sender address (may be "")
1473 routed if not NULL, set TRUE if routing succeeded, so we can
1474 distinguish between routing failed and callout failed
1476 Returns: OK address verified
1477 FAIL address failed to verify
1478 DEFER can't tell at present
1482 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1483 int callout_overall, int callout_connect, uschar *se_mailfrom,
1484 uschar *pm_mailfrom, BOOL *routed)
1487 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1488 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1489 BOOL expn = (options & vopt_expn) != 0;
1490 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1493 int verify_type = expn? v_expn :
1494 address_test_mode? v_none :
1495 is_recipient? v_recipient : v_sender;
1496 address_item *addr_list;
1497 address_item *addr_new = NULL;
1498 address_item *addr_remote = NULL;
1499 address_item *addr_local = NULL;
1500 address_item *addr_succeed = NULL;
1501 uschar **failure_ptr = is_recipient?
1502 &recipient_verify_failure : &sender_verify_failure;
1503 uschar *ko_prefix, *cr;
1504 uschar *address = vaddr->address;
1505 uschar *save_sender;
1506 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1508 /* Clear, just in case */
1510 *failure_ptr = NULL;
1512 /* Set up a prefix and suffix for error message which allow us to use the same
1513 output statements both in EXPN mode (where an SMTP response is needed) and when
1514 debugging with an output file. */
1518 ko_prefix = US"553 ";
1521 else ko_prefix = cr = US"";
1523 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1525 if (parse_find_at(address) == NULL)
1527 if ((options & vopt_qualify) == 0)
1530 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1531 ko_prefix, address, cr);
1532 *failure_ptr = US"qualify";
1535 address = rewrite_address_qualify(address, is_recipient);
1540 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1541 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1544 /* Rewrite and report on it. Clear the domain and local part caches - these
1545 may have been set by domains and local part tests during an ACL. */
1547 if (global_rewrite_rules != NULL)
1549 uschar *old = address;
1550 address = rewrite_address(address, is_recipient, FALSE,
1551 global_rewrite_rules, rewrite_existflags);
1554 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1555 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1556 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1560 /* If this is the real sender address, we must update sender_address at
1561 this point, because it may be referred to in the routers. */
1563 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1564 sender_address = address;
1566 /* If the address was rewritten to <> no verification can be done, and we have
1567 to return OK. This rewriting is permitted only for sender addresses; for other
1568 addresses, such rewriting fails. */
1570 if (address[0] == 0) return OK;
1572 /* Flip the legacy TLS-related variables over to the outbound set in case
1573 they're used in the context of a transport used by verification. Reset them
1574 at exit from this routine. */
1576 modify_variable(US"tls_bits", &tls_out.bits);
1577 modify_variable(US"tls_certificate_verified", &tls_out.certificate_verified);
1578 modify_variable(US"tls_cipher", &tls_out.cipher);
1579 modify_variable(US"tls_peerdn", &tls_out.peerdn);
1580 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1581 modify_variable(US"tls_sni", &tls_out.sni);
1584 /* Save a copy of the sender address for re-instating if we change it to <>
1585 while verifying a sender address (a nice bit of self-reference there). */
1587 save_sender = sender_address;
1589 /* Update the address structure with the possibly qualified and rewritten
1590 address. Set it up as the starting address on the chain of new addresses. */
1592 vaddr->address = address;
1595 /* We need a loop, because an address can generate new addresses. We must also
1596 cope with generated pipes and files at the top level. (See also the code and
1597 comment in deliver.c.) However, it is usually the case that the router for
1598 user's .forward files has its verify flag turned off.
1600 If an address generates more than one child, the loop is used only when
1601 full_info is set, and this can only be set locally. Remote enquiries just get
1602 information about the top level address, not anything that it generated. */
1604 while (addr_new != NULL)
1607 address_item *addr = addr_new;
1609 addr_new = addr->next;
1614 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1615 debug_printf("Considering %s\n", addr->address);
1618 /* Handle generated pipe, file or reply addresses. We don't get these
1619 when handling EXPN, as it does only one level of expansion. */
1621 if (testflag(addr, af_pfr))
1628 if (addr->address[0] == '>')
1630 allow = testflag(addr, af_allow_reply);
1631 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1635 allow = (addr->address[0] == '|')?
1636 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1637 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1640 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1641 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1642 "%s\n", addr->message);
1644 fprintf(f, "\n transport = %s\n", addr->transport->name);
1646 fprintf(f, " *** forbidden ***\n");
1651 /* Just in case some router parameter refers to it. */
1653 return_path = (addr->p.errors_address != NULL)?
1654 addr->p.errors_address : sender_address;
1656 /* Split the address into domain and local part, handling the %-hack if
1657 necessary, and then route it. While routing a sender address, set
1658 $sender_address to <> because that is what it will be if we were trying to
1659 send a bounce to the sender. */
1661 if (routed != NULL) *routed = FALSE;
1662 if ((rc = deliver_split_address(addr)) == OK)
1664 if (!is_recipient) sender_address = null_sender;
1665 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1666 &addr_succeed, verify_type);
1667 sender_address = save_sender; /* Put back the real sender */
1670 /* If routing an address succeeded, set the flag that remembers, for use when
1671 an ACL cached a sender verify (in case a callout fails). Then if routing set
1672 up a list of hosts or the transport has a host list, and the callout option
1673 is set, and we aren't in a host checking run, do the callout verification,
1674 and set another flag that notes that a callout happened. */
1678 if (routed != NULL) *routed = TRUE;
1681 host_item *host_list = addr->host_list;
1683 /* Make up some data for use in the case where there is no remote
1686 transport_feedback tf = {
1687 NULL, /* interface (=> any) */
1688 US"smtp", /* port */
1689 US"smtp", /* protocol */
1691 US"$smtp_active_hostname", /* helo_data */
1692 FALSE, /* hosts_override */
1693 FALSE, /* hosts_randomize */
1694 FALSE, /* gethostbyname */
1695 TRUE, /* qualify_single */
1696 FALSE /* search_parents */
1699 /* If verification yielded a remote transport, we want to use that
1700 transport's options, so as to mimic what would happen if we were really
1701 sending a message to this address. */
1703 if (addr->transport != NULL && !addr->transport->info->local)
1705 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1707 /* If the transport has hosts and the router does not, or if the
1708 transport is configured to override the router's hosts, we must build a
1709 host list of the transport's hosts, and find the IP addresses */
1711 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1714 uschar *save_deliver_domain = deliver_domain;
1715 uschar *save_deliver_localpart = deliver_localpart;
1717 host_list = NULL; /* Ignore the router's hosts */
1719 deliver_domain = addr->domain;
1720 deliver_localpart = addr->local_part;
1721 s = expand_string(tf.hosts);
1722 deliver_domain = save_deliver_domain;
1723 deliver_localpart = save_deliver_localpart;
1727 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1728 "\"%s\" in %s transport for callout: %s", tf.hosts,
1729 addr->transport->name, expand_string_message);
1734 uschar *canonical_name;
1735 host_item *host, *nexthost;
1736 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1738 /* Just ignore failures to find a host address. If we don't manage
1739 to find any addresses, the callout will defer. Note that more than
1740 one address may be found for a single host, which will result in
1741 additional host items being inserted into the chain. Hence we must
1742 save the next host first. */
1744 flags = HOST_FIND_BY_A;
1745 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1746 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1748 for (host = host_list; host != NULL; host = nexthost)
1750 nexthost = host->next;
1751 if (tf.gethostbyname ||
1752 string_is_ip_address(host->name, NULL) != 0)
1753 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1755 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1756 &canonical_name, NULL);
1762 /* Can only do a callout if we have at least one host! If the callout
1763 fails, it will have set ${sender,recipient}_verify_failure. */
1765 if (host_list != NULL)
1767 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1768 if (host_checking && !host_checking_callout)
1771 debug_printf("... callout omitted by default when host testing\n"
1772 "(Use -bhc if you want the callouts to happen.)\n");
1777 deliver_set_expansions(addr);
1779 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1780 callout_connect, options, se_mailfrom, pm_mailfrom);
1785 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1786 "transport provided a host list\n");
1791 /* Otherwise, any failure is a routing failure */
1793 else *failure_ptr = US"route";
1795 /* A router may return REROUTED if it has set up a child address as a result
1796 of a change of domain name (typically from widening). In this case we always
1797 want to continue to verify the new child. */
1799 if (rc == REROUTED) continue;
1801 /* Handle hard failures */
1808 address_item *p = addr->parent;
1810 respond_printf(f, "%s%s %s", ko_prefix,
1811 full_info? addr->address : address,
1812 address_test_mode? "is undeliverable" : "failed to verify");
1813 if (!expn && admin_user)
1815 if (addr->basic_errno > 0)
1816 respond_printf(f, ": %s", strerror(addr->basic_errno));
1817 if (addr->message != NULL)
1818 respond_printf(f, ": %s", addr->message);
1821 /* Show parents iff doing full info */
1823 if (full_info) while (p != NULL)
1825 respond_printf(f, "%s\n <-- %s", cr, p->address);
1828 respond_printf(f, "%s\n", cr);
1830 cancel_cutthrough_connection("routing hard fail");
1834 yield = copy_error(vaddr, addr, FAIL);
1842 else if (rc == DEFER)
1847 address_item *p = addr->parent;
1848 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1849 full_info? addr->address : address);
1850 if (!expn && admin_user)
1852 if (addr->basic_errno > 0)
1853 respond_printf(f, ": %s", strerror(addr->basic_errno));
1854 if (addr->message != NULL)
1855 respond_printf(f, ": %s", addr->message);
1856 else if (addr->basic_errno <= 0)
1857 respond_printf(f, ": unknown error");
1860 /* Show parents iff doing full info */
1862 if (full_info) while (p != NULL)
1864 respond_printf(f, "%s\n <-- %s", cr, p->address);
1867 respond_printf(f, "%s\n", cr);
1869 cancel_cutthrough_connection("routing soft fail");
1873 yield = copy_error(vaddr, addr, DEFER);
1876 else if (yield == OK) yield = DEFER;
1879 /* If we are handling EXPN, we do not want to continue to route beyond
1880 the top level (whose address is in "address"). */
1884 uschar *ok_prefix = US"250-";
1885 if (addr_new == NULL)
1887 if (addr_local == NULL && addr_remote == NULL)
1888 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1890 respond_printf(f, "250 <%s>\r\n", address);
1892 else while (addr_new != NULL)
1894 address_item *addr2 = addr_new;
1895 addr_new = addr2->next;
1896 if (addr_new == NULL) ok_prefix = US"250 ";
1897 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1903 /* Successful routing other than EXPN. */
1907 /* Handle successful routing when short info wanted. Otherwise continue for
1908 other (generated) addresses. Short info is the operational case. Full info
1909 can be requested only when debug_selector != 0 and a file is supplied.
1911 There is a conflict between the use of aliasing as an alternate email
1912 address, and as a sort of mailing list. If an alias turns the incoming
1913 address into just one address (e.g. J.Caesar->jc44) you may well want to
1914 carry on verifying the generated address to ensure it is valid when
1915 checking incoming mail. If aliasing generates multiple addresses, you
1916 probably don't want to do this. Exim therefore treats the generation of
1917 just a single new address as a special case, and continues on to verify the
1918 generated address. */
1920 if (!full_info && /* Stop if short info wanted AND */
1921 (((addr_new == NULL || /* No new address OR */
1922 addr_new->next != NULL || /* More than one new address OR */
1923 testflag(addr_new, af_pfr))) /* New address is pfr */
1925 (addr_new != NULL && /* At least one new address AND */
1926 success_on_redirect))) /* success_on_redirect is set */
1928 if (f != NULL) fprintf(f, "%s %s\n", address,
1929 address_test_mode? "is deliverable" : "verified");
1931 /* If we have carried on to verify a child address, we want the value
1932 of $address_data to be that of the child */
1934 vaddr->p.address_data = addr->p.address_data;
1939 } /* Loop for generated addresses */
1941 /* Display the full results of the successful routing, including any generated
1942 addresses. Control gets here only when full_info is set, which requires f not
1943 to be NULL, and this occurs only when a top-level verify is called with the
1944 debugging switch on.
1946 If there are no local and no remote addresses, and there were no pipes, files,
1947 or autoreplies, and there were no errors or deferments, the message is to be
1948 discarded, usually because of the use of :blackhole: in an alias file. */
1950 if (allok && addr_local == NULL && addr_remote == NULL)
1952 fprintf(f, "mail to %s is discarded\n", address);
1956 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1958 while (addr_list != NULL)
1960 address_item *addr = addr_list;
1961 address_item *p = addr->parent;
1962 addr_list = addr->next;
1964 fprintf(f, "%s", CS addr->address);
1965 #ifdef EXPERIMENTAL_SRS
1966 if(addr->p.srs_sender)
1967 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1970 /* If the address is a duplicate, show something about it. */
1972 if (!testflag(addr, af_pfr))
1975 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1976 fprintf(f, " [duplicate, would not be delivered]");
1977 else tree_add_duplicate(addr->unique, addr);
1980 /* Now show its parents */
1984 fprintf(f, "\n <-- %s", p->address);
1989 /* Show router, and transport */
1991 fprintf(f, "router = %s, ", addr->router->name);
1992 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1993 addr->transport->name);
1995 /* Show any hosts that are set up by a router unless the transport
1996 is going to override them; fiddle a bit to get a nice format. */
1998 if (addr->host_list != NULL && addr->transport != NULL &&
1999 !addr->transport->overrides_hosts)
2004 for (h = addr->host_list; h != NULL; h = h->next)
2006 int len = Ustrlen(h->name);
2007 if (len > maxlen) maxlen = len;
2008 len = (h->address != NULL)? Ustrlen(h->address) : 7;
2009 if (len > maxaddlen) maxaddlen = len;
2011 for (h = addr->host_list; h != NULL; h = h->next)
2013 int len = Ustrlen(h->name);
2014 fprintf(f, " host %s ", h->name);
2015 while (len++ < maxlen) fprintf(f, " ");
2016 if (h->address != NULL)
2018 fprintf(f, "[%s] ", h->address);
2019 len = Ustrlen(h->address);
2021 else if (!addr->transport->info->local) /* Omit [unknown] for local */
2023 fprintf(f, "[unknown] ");
2027 while (len++ < maxaddlen) fprintf(f," ");
2028 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
2029 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2030 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
2037 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2038 the -bv or -bt case). */
2042 modify_variable(US"tls_bits", &tls_in.bits);
2043 modify_variable(US"tls_certificate_verified", &tls_in.certificate_verified);
2044 modify_variable(US"tls_cipher", &tls_in.cipher);
2045 modify_variable(US"tls_peerdn", &tls_in.peerdn);
2046 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
2047 modify_variable(US"tls_sni", &tls_in.sni);
2056 /*************************************************
2057 * Check headers for syntax errors *
2058 *************************************************/
2060 /* This function checks those header lines that contain addresses, and verifies
2061 that all the addresses therein are syntactially correct.
2064 msgptr where to put an error message
2071 verify_check_headers(uschar **msgptr)
2077 for (h = header_list; h != NULL && yield == OK; h = h->next)
2079 if (h->type != htype_from &&
2080 h->type != htype_reply_to &&
2081 h->type != htype_sender &&
2082 h->type != htype_to &&
2083 h->type != htype_cc &&
2084 h->type != htype_bcc)
2087 colon = Ustrchr(h->text, ':');
2089 while (isspace(*s)) s++;
2091 /* Loop for multiple addresses in the header, enabling group syntax. Note
2092 that we have to reset this after the header has been scanned. */
2094 parse_allow_group = TRUE;
2098 uschar *ss = parse_find_address_end(s, FALSE);
2099 uschar *recipient, *errmess;
2100 int terminator = *ss;
2101 int start, end, domain;
2103 /* Temporarily terminate the string at this point, and extract the
2104 operative address within, allowing group syntax. */
2107 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2110 /* Permit an unqualified address only if the message is local, or if the
2111 sending host is configured to be permitted to send them. */
2113 if (recipient != NULL && domain == 0)
2115 if (h->type == htype_from || h->type == htype_sender)
2117 if (!allow_unqualified_sender) recipient = NULL;
2121 if (!allow_unqualified_recipient) recipient = NULL;
2123 if (recipient == NULL) errmess = US"unqualified address not permitted";
2126 /* It's an error if no address could be extracted, except for the special
2127 case of an empty address. */
2129 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2131 uschar *verb = US"is";
2136 /* Arrange not to include any white space at the end in the
2137 error message or the header name. */
2139 while (t > s && isspace(t[-1])) t--;
2140 while (tt > h->text && isspace(tt[-1])) tt--;
2142 /* Add the address that failed to the error message, since in a
2143 header with very many addresses it is sometimes hard to spot
2144 which one is at fault. However, limit the amount of address to
2145 quote - cases have been seen where, for example, a missing double
2146 quote in a humungous To: header creates an "address" that is longer
2147 than string_sprintf can handle. */
2156 *msgptr = string_printing(
2157 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2158 errmess, tt - h->text, h->text, verb, len, s));
2161 break; /* Out of address loop */
2164 /* Advance to the next address */
2166 s = ss + (terminator? 1:0);
2167 while (isspace(*s)) s++;
2168 } /* Next address */
2170 parse_allow_group = FALSE;
2171 parse_found_group = FALSE;
2172 } /* Next header unless yield has been set FALSE */
2178 /*************************************************
2179 * Check header names for 8-bit characters *
2180 *************************************************/
2182 /* This function checks for invalid charcters in header names. See
2183 RFC 5322, 2.2. and RFC 6532, 3.
2186 msgptr where to put an error message
2193 verify_check_header_names_ascii(uschar **msgptr)
2198 for (h = header_list; h != NULL; h = h->next)
2200 colon = Ustrchr(h->text, ':');
2201 for(s = h->text; s < colon; s++)
2203 if ((*s < 33) || (*s > 126))
2205 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2206 colon - h->text, h->text);
2214 /*************************************************
2215 * Check for blind recipients *
2216 *************************************************/
2218 /* This function checks that every (envelope) recipient is mentioned in either
2219 the To: or Cc: header lines, thus detecting blind carbon copies.
2221 There are two ways of scanning that could be used: either scan the header lines
2222 and tick off the recipients, or scan the recipients and check the header lines.
2223 The original proposed patch did the former, but I have chosen to do the latter,
2224 because (a) it requires no memory and (b) will use fewer resources when there
2225 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2228 Returns: OK if there are no blind recipients
2229 FAIL if there is at least one blind recipient
2233 verify_check_notblind(void)
2236 for (i = 0; i < recipients_count; i++)
2240 uschar *address = recipients_list[i].address;
2242 for (h = header_list; !found && h != NULL; h = h->next)
2246 if (h->type != htype_to && h->type != htype_cc) continue;
2248 colon = Ustrchr(h->text, ':');
2250 while (isspace(*s)) s++;
2252 /* Loop for multiple addresses in the header, enabling group syntax. Note
2253 that we have to reset this after the header has been scanned. */
2255 parse_allow_group = TRUE;
2259 uschar *ss = parse_find_address_end(s, FALSE);
2260 uschar *recipient,*errmess;
2261 int terminator = *ss;
2262 int start, end, domain;
2264 /* Temporarily terminate the string at this point, and extract the
2265 operative address within, allowing group syntax. */
2268 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2271 /* If we found a valid recipient that has a domain, compare it with the
2272 envelope recipient. Local parts are compared case-sensitively, domains
2273 case-insensitively. By comparing from the start with length "domain", we
2274 include the "@" at the end, which ensures that we are comparing the whole
2275 local part of each address. */
2277 if (recipient != NULL && domain != 0)
2279 found = Ustrncmp(recipient, address, domain) == 0 &&
2280 strcmpic(recipient + domain, address + domain) == 0;
2284 /* Advance to the next address */
2286 s = ss + (terminator? 1:0);
2287 while (isspace(*s)) s++;
2288 } /* Next address */
2290 parse_allow_group = FALSE;
2291 parse_found_group = FALSE;
2292 } /* Next header (if found is false) */
2294 if (!found) return FAIL;
2295 } /* Next recipient */
2302 /*************************************************
2303 * Find if verified sender *
2304 *************************************************/
2306 /* Usually, just a single address is verified as the sender of the message.
2307 However, Exim can be made to verify other addresses as well (often related in
2308 some way), and this is useful in some environments. There may therefore be a
2309 chain of such addresses that have previously been tested. This function finds
2310 whether a given address is on the chain.
2312 Arguments: the address to be verified
2313 Returns: pointer to an address item, or NULL
2317 verify_checked_sender(uschar *sender)
2320 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2321 if (Ustrcmp(sender, addr->address) == 0) break;
2329 /*************************************************
2330 * Get valid header address *
2331 *************************************************/
2333 /* Scan the originator headers of the message, looking for an address that
2334 verifies successfully. RFC 822 says:
2336 o The "Sender" field mailbox should be sent notices of
2337 any problems in transport or delivery of the original
2338 messages. If there is no "Sender" field, then the
2339 "From" field mailbox should be used.
2341 o If the "Reply-To" field exists, then the reply should
2342 go to the addresses indicated in that field and not to
2343 the address(es) indicated in the "From" field.
2345 So we check a Sender field if there is one, else a Reply_to field, else a From
2346 field. As some strange messages may have more than one of these fields,
2347 especially if they are resent- fields, check all of them if there is more than
2351 user_msgptr points to where to put a user error message
2352 log_msgptr points to where to put a log error message
2353 callout timeout for callout check (passed to verify_address())
2354 callout_overall overall callout timeout (ditto)
2355 callout_connect connect callout timeout (ditto)
2356 se_mailfrom mailfrom for verify; NULL => ""
2357 pm_mailfrom sender for pm callout check (passed to verify_address())
2358 options callout options (passed to verify_address())
2359 verrno where to put the address basic_errno
2361 If log_msgptr is set to something without setting user_msgptr, the caller
2362 normally uses log_msgptr for both things.
2364 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2365 FAIL is given if no appropriate headers are found
2369 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2370 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2371 uschar *pm_mailfrom, int options, int *verrno)
2373 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2378 for (i = 0; i < 3 && !done; i++)
2381 for (h = header_list; h != NULL && !done; h = h->next)
2383 int terminator, new_ok;
2384 uschar *s, *ss, *endname;
2386 if (h->type != header_types[i]) continue;
2387 s = endname = Ustrchr(h->text, ':') + 1;
2389 /* Scan the addresses in the header, enabling group syntax. Note that we
2390 have to reset this after the header has been scanned. */
2392 parse_allow_group = TRUE;
2396 address_item *vaddr;
2398 while (isspace(*s) || *s == ',') s++;
2399 if (*s == 0) break; /* End of header */
2401 ss = parse_find_address_end(s, FALSE);
2403 /* The terminator is a comma or end of header, but there may be white
2404 space preceding it (including newline for the last address). Move back
2405 past any white space so we can check against any cached envelope sender
2406 address verifications. */
2408 while (isspace(ss[-1])) ss--;
2412 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2413 (int)(endname - h->text), h->text, s);
2415 /* See if we have already verified this address as an envelope sender,
2416 and if so, use the previous answer. */
2418 vaddr = verify_checked_sender(s);
2420 if (vaddr != NULL && /* Previously checked */
2421 (callout <= 0 || /* No callout needed; OR */
2422 vaddr->special_action > 256)) /* Callout was done */
2424 new_ok = vaddr->special_action & 255;
2425 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2426 *ss = terminator; /* Restore shortened string */
2429 /* Otherwise we run the verification now. We must restore the shortened
2430 string before running the verification, so the headers are correct, in
2431 case there is any rewriting. */
2435 int start, end, domain;
2436 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2441 /* If we found an empty address, just carry on with the next one, but
2442 kill the message. */
2444 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2451 /* If verification failed because of a syntax error, fail this
2452 function, and ensure that the failing address gets added to the error
2455 if (address == NULL)
2458 while (ss > s && isspace(ss[-1])) ss--;
2459 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2460 "scanning for sender: %s in \"%.*s\"",
2461 endname - h->text, h->text, *log_msgptr, ss - s, s);
2467 /* Else go ahead with the sender verification. But it isn't *the*
2468 sender of the message, so set vopt_fake_sender to stop sender_address
2469 being replaced after rewriting or qualification. */
2473 vaddr = deliver_make_addr(address, FALSE);
2474 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2475 callout, callout_overall, callout_connect, se_mailfrom,
2480 /* We now have the result, either newly found, or cached. If we are
2481 giving out error details, set a specific user error. This means that the
2482 last of these will be returned to the user if all three fail. We do not
2483 set a log message - the generic one below will be used. */
2487 *verrno = vaddr->basic_errno;
2488 if (smtp_return_error_details)
2490 *user_msgptr = string_sprintf("Rejected after DATA: "
2491 "could not verify \"%.*s\" header address\n%s: %s",
2492 endname - h->text, h->text, vaddr->address, vaddr->message);
2496 /* Success or defer */
2505 if (new_ok == DEFER) yield = DEFER;
2507 /* Move on to any more addresses in the header */
2510 } /* Next address */
2512 parse_allow_group = FALSE;
2513 parse_found_group = FALSE;
2514 } /* Next header, unless done */
2515 } /* Next header type unless done */
2517 if (yield == FAIL && *log_msgptr == NULL)
2518 *log_msgptr = US"there is no valid sender in any header line";
2520 if (yield == DEFER && *log_msgptr == NULL)
2521 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2529 /*************************************************
2530 * Get RFC 1413 identification *
2531 *************************************************/
2533 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2534 the timeout is set to zero, then the query is not done. There may also be lists
2535 of hosts and nets which are exempt. To guard against malefactors sending
2536 non-printing characters which could, for example, disrupt a message's headers,
2537 make sure the string consists of printing characters only.
2540 port the port to connect to; usually this is IDENT_PORT (113), but when
2541 running in the test harness with -bh a different value is used.
2545 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2549 verify_get_ident(int port)
2551 int sock, host_af, qlen;
2552 int received_sender_port, received_interface_port, n;
2554 uschar buffer[2048];
2556 /* Default is no ident. Check whether we want to do an ident check for this
2559 sender_ident = NULL;
2560 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2563 DEBUG(D_ident) debug_printf("doing ident callback\n");
2565 /* Set up a connection to the ident port of the remote host. Bind the local end
2566 to the incoming interface address. If the sender host address is an IPv6
2567 address, the incoming interface address will also be IPv6. */
2569 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2570 sock = ip_socket(SOCK_STREAM, host_af);
2571 if (sock < 0) return;
2573 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2575 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2580 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2583 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2585 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2586 sender_host_address);
2590 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2591 sender_host_address, strerror(errno));
2596 /* Construct and send the query. */
2598 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2599 qlen = Ustrlen(buffer);
2600 if (send(sock, buffer, qlen, 0) < 0)
2602 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2606 /* Read a response line. We put it into the rest of the buffer, using several
2607 recv() calls if necessary. */
2615 int size = sizeof(buffer) - (p - buffer);
2617 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2618 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2619 if (count <= 0) goto END_OFF; /* Read error or EOF */
2621 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2622 generous, and accept a plain \n terminator as well. The only illegal
2625 for (pp = p; pp < p + count; pp++)
2627 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2630 if (pp[-1] == '\r') pp--;
2632 goto GOT_DATA; /* Break out of both loops */
2636 /* Reached the end of the data without finding \n. Let the loop continue to
2637 read some more, if there is room. */
2644 /* We have received a line of data. Check it carefully. It must start with the
2645 same two port numbers that we sent, followed by data as defined by the RFC. For
2648 12345 , 25 : USERID : UNIX :root
2650 However, the amount of white space may be different to what we sent. In the
2651 "osname" field there may be several sub-fields, comma separated. The data we
2652 actually want to save follows the third colon. Some systems put leading spaces
2653 in it - we discard those. */
2655 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2656 &received_interface_port, &n) != 2 ||
2657 received_sender_port != sender_host_port ||
2658 received_interface_port != interface_port)
2661 p = buffer + qlen + n;
2662 while(isspace(*p)) p++;
2663 if (*p++ != ':') goto END_OFF;
2664 while(isspace(*p)) p++;
2665 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2667 while(isspace(*p)) p++;
2668 if (*p++ != ':') goto END_OFF;
2669 while (*p != 0 && *p != ':') p++;
2670 if (*p++ == 0) goto END_OFF;
2671 while(isspace(*p)) p++;
2672 if (*p == 0) goto END_OFF;
2674 /* The rest of the line is the data we want. We turn it into printing
2675 characters when we save it, so that it cannot mess up the format of any logging
2676 or Received: lines into which it gets inserted. We keep a maximum of 127
2679 sender_ident = string_printing(string_copyn(p, 127));
2680 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2690 /*************************************************
2691 * Match host to a single host-list item *
2692 *************************************************/
2694 /* This function compares a host (name or address) against a single item
2695 from a host list. The host name gets looked up if it is needed and is not
2696 already known. The function is called from verify_check_this_host() via
2697 match_check_list(), which is why most of its arguments are in a single block.
2700 arg the argument block (see below)
2701 ss the host-list item
2702 valueptr where to pass back looked up data, or NULL
2703 error for error message when returning ERROR
2706 host_name (a) the host name, or
2707 (b) NULL, implying use sender_host_name and
2708 sender_host_aliases, looking them up if required, or
2709 (c) the empty string, meaning that only IP address matches
2711 host_address the host address
2712 host_ipv4 the IPv4 address taken from an IPv6 one
2716 DEFER lookup deferred
2717 ERROR (a) failed to find the host name or IP address, or
2718 (b) unknown lookup type specified, or
2719 (c) host name encountered when only IP addresses are
2724 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2726 check_host_block *cb = (check_host_block *)arg;
2729 BOOL iplookup = FALSE;
2730 BOOL isquery = FALSE;
2731 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2736 /* Optimize for the special case when the pattern is "*". */
2738 if (*ss == '*' && ss[1] == 0) return OK;
2740 /* If the pattern is empty, it matches only in the case when there is no host -
2741 this can occur in ACL checking for SMTP input using the -bs option. In this
2742 situation, the host address is the empty string. */
2744 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2745 if (*ss == 0) return FAIL;
2747 /* If the pattern is precisely "@" then match against the primary host name,
2748 provided that host name matching is permitted; if it's "@[]" match against the
2749 local host's IP addresses. */
2755 if (isiponly) return ERROR;
2756 ss = primary_hostname;
2758 else if (Ustrcmp(ss, "@[]") == 0)
2760 ip_address_item *ip;
2761 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2762 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2767 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2768 a (possibly masked) comparision with the current IP address. */
2770 if (string_is_ip_address(ss, &maskoffset) != 0)
2771 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2773 /* The pattern is not an IP address. A common error that people make is to omit
2774 one component of an IPv4 address, either by accident, or believing that, for
2775 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,
2776 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2777 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2778 ancient specification.) To aid in debugging these cases, we give a specific
2779 error if the pattern contains only digits and dots or contains a slash preceded
2780 only by digits and dots (a slash at the start indicates a file name and of
2781 course slashes may be present in lookups, but not preceded only by digits and
2784 for (t = ss; isdigit(*t) || *t == '.'; t++);
2785 if (*t == 0 || (*t == '/' && t != ss))
2787 *error = US"malformed IPv4 address or address mask";
2791 /* See if there is a semicolon in the pattern */
2793 semicolon = Ustrchr(ss, ';');
2795 /* If we are doing an IP address only match, then all lookups must be IP
2796 address lookups, even if there is no "net-". */
2800 iplookup = semicolon != NULL;
2803 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2804 a lookup on a masked IP network, in textual form. We obey this code even if we
2805 have already set iplookup, so as to skip over the "net-" prefix and to set the
2806 mask length. The net- stuff really only applies to single-key lookups where the
2807 key is implicit. For query-style lookups the key is specified in the query.
2808 From release 4.30, the use of net- for query style is no longer needed, but we
2809 retain it for backward compatibility. */
2811 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2814 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2815 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2816 iplookup = (*t++ == '-');
2820 /* Do the IP address lookup if that is indeed what we have */
2828 uschar *filename, *key, *result;
2831 /* Find the search type */
2833 search_type = search_findtype(t, semicolon - t);
2835 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2836 search_error_message);
2838 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2839 is no file name, and the "key" is just the query. For query-style with a file
2840 name, we have to fish the file off the start of the query. For a single-key
2841 lookup, the key is the current IP address, masked appropriately, and
2842 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2843 dot separators instead of colons, except when the lookup type is "iplsearch".
2846 if (mac_islookup(search_type, lookup_absfilequery))
2848 filename = semicolon + 1;
2850 while (*key != 0 && !isspace(*key)) key++;
2851 filename = string_copyn(filename, key - filename);
2852 while (isspace(*key)) key++;
2854 else if (mac_islookup(search_type, lookup_querystyle))
2857 key = semicolon + 1;
2859 else /* Single-key style */
2861 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2863 insize = host_aton(cb->host_address, incoming);
2864 host_mask(insize, incoming, mlen);
2865 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2867 filename = semicolon + 1;
2870 /* Now do the actual lookup; note that there is no search_close() because
2871 of the caching arrangements. */
2873 handle = search_open(filename, search_type, 0, NULL, NULL);
2874 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2875 search_error_message);
2876 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2877 if (valueptr != NULL) *valueptr = result;
2878 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2881 /* The pattern is not an IP address or network reference of any kind. That is,
2882 it is a host name pattern. If this is an IP only match, there's an error in the
2887 *error = US"cannot match host name in match_ip list";
2891 /* Check the characters of the pattern to see if they comprise only letters,
2892 digits, full stops, and hyphens (the constituents of domain names). Allow
2893 underscores, as they are all too commonly found. Sigh. Also, if
2894 allow_utf8_domains is set, allow top-bit characters. */
2896 for (t = ss; *t != 0; t++)
2897 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2898 (!allow_utf8_domains || *t < 128)) break;
2900 /* If the pattern is a complete domain name, with no fancy characters, look up
2901 its IP address and match against that. Note that a multi-homed host will add
2902 items to the chain. */
2913 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2914 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2917 for (hh = &h; hh != NULL; hh = hh->next)
2919 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2923 if (rc == HOST_FIND_AGAIN) return DEFER;
2924 *error = string_sprintf("failed to find IP address for %s", ss);
2928 /* Almost all subsequent comparisons require the host name, and can be done
2929 using the general string matching function. When this function is called for
2930 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2931 must use sender_host_name and its aliases, looking them up if necessary. */
2933 if (cb->host_name != NULL) /* Explicit host name given */
2934 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2937 /* Host name not given; in principle we need the sender host name and its
2938 aliases. However, for query-style lookups, we do not need the name if the
2939 query does not contain $sender_host_name. From release 4.23, a reference to
2940 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2943 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2946 int partial, affixlen, starflags, id;
2949 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2952 if (id < 0) /* Unknown lookup type */
2954 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2955 search_error_message, ss);
2958 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2963 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2966 case DEFER: return DEFER;
2967 default: return FAIL;
2971 /* Not a query-style lookup; must ensure the host name is present, and then we
2972 do a check on the name and all its aliases. */
2974 if (sender_host_name == NULL)
2976 HDEBUG(D_host_lookup)
2977 debug_printf("sender host name required, to match against %s\n", ss);
2978 if (host_lookup_failed || host_name_lookup() != OK)
2980 *error = string_sprintf("failed to find host name for %s",
2981 sender_host_address);;
2984 host_build_sender_fullhost();
2987 /* Match on the sender host name, using the general matching function */
2989 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2993 case DEFER: return DEFER;
2996 /* If there are aliases, try matching on them. */
2998 aliases = sender_host_aliases;
2999 while (*aliases != NULL)
3001 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3004 case DEFER: return DEFER;
3013 /*************************************************
3014 * Check a specific host matches a host list *
3015 *************************************************/
3017 /* This function is passed a host list containing items in a number of
3018 different formats and the identity of a host. Its job is to determine whether
3019 the given host is in the set of hosts defined by the list. The host name is
3020 passed as a pointer so that it can be looked up if needed and not already
3021 known. This is commonly the case when called from verify_check_host() to check
3022 an incoming connection. When called from elsewhere the host name should usually
3025 This function is now just a front end to match_check_list(), which runs common
3026 code for scanning a list. We pass it the check_host() function to perform a
3030 listptr pointer to the host list
3031 cache_bits pointer to cache for named lists, or NULL
3032 host_name the host name or NULL, implying use sender_host_name and
3033 sender_host_aliases, looking them up if required
3034 host_address the IP address
3035 valueptr if not NULL, data from a lookup is passed back here
3037 Returns: OK if the host is in the defined set
3038 FAIL if the host is not in the defined set,
3039 DEFER if a data lookup deferred (not a host lookup)
3041 If the host name was needed in order to make a comparison, and could not be
3042 determined from the IP address, the result is FAIL unless the item
3043 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3046 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
3047 uschar *host_name, uschar *host_address, uschar **valueptr)
3050 unsigned int *local_cache_bits = cache_bits;
3051 uschar *save_host_address = deliver_host_address;
3052 check_host_block cb;
3053 cb.host_name = host_name;
3054 cb.host_address = host_address;
3056 if (valueptr != NULL) *valueptr = NULL;
3058 /* If the host address starts off ::ffff: it is an IPv6 address in
3059 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3062 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3063 host_address + 7 : host_address;
3065 /* During the running of the check, put the IP address into $host_address. In
3066 the case of calls from the smtp transport, it will already be there. However,
3067 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3068 the safe side, any existing setting is preserved, though as I write this
3069 (November 2004) I can't see any cases where it is actually needed. */
3071 deliver_host_address = host_address;
3072 rc = match_check_list(
3073 listptr, /* the list */
3074 0, /* separator character */
3075 &hostlist_anchor, /* anchor pointer */
3076 &local_cache_bits, /* cache pointer */
3077 check_host, /* function for testing */
3078 &cb, /* argument for function */
3079 MCL_HOST, /* type of check */
3080 (host_address == sender_host_address)?
3081 US"host" : host_address, /* text for debugging */
3082 valueptr); /* where to pass back data */
3083 deliver_host_address = save_host_address;
3090 /*************************************************
3091 * Check the remote host matches a list *
3092 *************************************************/
3094 /* This is a front end to verify_check_this_host(), created because checking
3095 the remote host is a common occurrence. With luck, a good compiler will spot
3096 the tail recursion and optimize it. If there's no host address, this is
3097 command-line SMTP input - check against an empty string for the address.
3100 listptr pointer to the host list
3102 Returns: the yield of verify_check_this_host(),
3103 i.e. OK, FAIL, or DEFER
3107 verify_check_host(uschar **listptr)
3109 return verify_check_this_host(listptr, sender_host_cache, NULL,
3110 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3117 /*************************************************
3118 * Invert an IP address *
3119 *************************************************/
3121 /* Originally just used for DNS xBL lists, now also used for the
3122 reverse_ip expansion operator.
3125 buffer where to put the answer
3126 address the address to invert
3130 invert_address(uschar *buffer, uschar *address)
3133 uschar *bptr = buffer;
3135 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3136 to the IPv4 part only. */
3138 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3140 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3143 if (host_aton(address, bin) == 1)
3147 for (i = 0; i < 4; i++)
3149 sprintf(CS bptr, "%d.", x & 255);
3150 while (*bptr) bptr++;
3155 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3156 in any DNS black lists, and the format in which they will be looked up is
3157 unknown. This is just a guess. */
3163 for (j = 3; j >= 0; j--)
3166 for (i = 0; i < 8; i++)
3168 sprintf(CS bptr, "%x.", x & 15);
3169 while (*bptr) bptr++;
3176 /* Remove trailing period -- this is needed so that both arbitrary
3177 dnsbl keydomains and inverted addresses may be combined with the
3178 same format string, "%s.%s" */
3185 /*************************************************
3186 * Perform a single dnsbl lookup *
3187 *************************************************/
3189 /* This function is called from verify_check_dnsbl() below. It is also called
3190 recursively from within itself when domain and domain_txt are different
3191 pointers, in order to get the TXT record from the alternate domain.
3194 domain the outer dnsbl domain
3195 domain_txt alternate domain to lookup TXT record on success; when the
3196 same domain is to be used, domain_txt == domain (that is,
3197 the pointers must be identical, not just the text)
3198 keydomain the current keydomain (for debug message)
3199 prepend subdomain to lookup (like keydomain, but
3200 reversed if IP address)
3201 iplist the list of matching IP addresses, or NULL for "any"
3202 bitmask true if bitmask matching is wanted
3203 match_type condition for 'succeed' result
3204 0 => Any RR in iplist (=)
3205 1 => No RR in iplist (!=)
3206 2 => All RRs in iplist (==)
3207 3 => Some RRs not in iplist (!==)
3208 the two bits are defined as MT_NOT and MT_ALL
3209 defer_return what to return for a defer
3211 Returns: OK if lookup succeeded
3216 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3217 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3223 dnsbl_cache_block *cb;
3224 int old_pool = store_pool;
3225 uschar query[256]; /* DNS domain max length */
3227 /* Construct the specific query domainname */
3229 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3231 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3232 "(ignored): %s...", query);
3236 /* Look for this query in the cache. */
3238 t = tree_search(dnsbl_cache, query);
3240 /* If not cached from a previous lookup, we must do a DNS lookup, and
3241 cache the result in permanent memory. */
3245 store_pool = POOL_PERM;
3247 /* Set up a tree entry to cache the lookup */
3249 t = store_get(sizeof(tree_node) + Ustrlen(query));
3250 Ustrcpy(t->name, query);
3251 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3252 (void)tree_insertnode(&dnsbl_cache, t);
3254 /* Do the DNS loopup . */
3256 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3257 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3258 cb->text_set = FALSE;
3262 /* If the lookup succeeded, cache the RHS address. The code allows for
3263 more than one address - this was for complete generality and the possible
3264 use of A6 records. However, A6 records have been reduced to experimental
3265 status (August 2001) and may die out. So they may never get used at all,
3266 let alone in dnsbl records. However, leave the code here, just in case.
3268 Quite apart from one A6 RR generating multiple addresses, there are DNS
3269 lists that return more than one A record, so we must handle multiple
3270 addresses generated in that way as well. */
3272 if (cb->rc == DNS_SUCCEED)
3275 dns_address **addrp = &(cb->rhs);
3276 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3278 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3280 if (rr->type == T_A)
3282 dns_address *da = dns_address_from_rr(&dnsa, rr);
3286 while (da->next != NULL) da = da->next;
3287 addrp = &(da->next);
3292 /* If we didn't find any A records, change the return code. This can
3293 happen when there is a CNAME record but there are no A records for what
3296 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3299 store_pool = old_pool;
3302 /* Previous lookup was cached */
3306 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3310 /* We now have the result of the DNS lookup, either newly done, or cached
3311 from a previous call. If the lookup succeeded, check against the address
3312 list if there is one. This may be a positive equality list (introduced by
3313 "="), a negative equality list (introduced by "!="), a positive bitmask
3314 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3316 if (cb->rc == DNS_SUCCEED)
3318 dns_address *da = NULL;
3319 uschar *addlist = cb->rhs->address;
3321 /* For A and AAAA records, there may be multiple addresses from multiple
3322 records. For A6 records (currently not expected to be used) there may be
3323 multiple addresses from a single record. */
3325 for (da = cb->rhs->next; da != NULL; da = da->next)
3326 addlist = string_sprintf("%s, %s", addlist, da->address);
3328 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3331 /* Address list check; this can be either for equality, or via a bitmask.
3332 In the latter case, all the bits must match. */
3336 for (da = cb->rhs; da != NULL; da = da->next)
3340 uschar *ptr = iplist;
3343 /* Handle exact matching */
3347 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3349 if (Ustrcmp(CS da->address, ip) == 0) break;
3353 /* Handle bitmask matching */
3360 /* At present, all known DNS blocking lists use A records, with
3361 IPv4 addresses on the RHS encoding the information they return. I
3362 wonder if this will linger on as the last vestige of IPv4 when IPv6
3363 is ubiquitous? Anyway, for now we use paranoia code to completely
3364 ignore IPv6 addresses. The default mask is 0, which always matches.
3365 We change this only for IPv4 addresses in the list. */
3367 if (host_aton(da->address, address) == 1) mask = address[0];
3369 /* Scan the returned addresses, skipping any that are IPv6 */
3371 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3373 if (host_aton(ip, address) != 1) continue;
3374 if ((address[0] & mask) == address[0]) break;
3380 (a) An IP address in an any ('=') list matched, or
3381 (b) No IP address in an all ('==') list matched
3383 then we're done searching. */
3385 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3388 /* If da == NULL, either
3390 (a) No IP address in an any ('=') list matched, or
3391 (b) An IP address in an all ('==') list didn't match
3393 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3396 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3404 res = US"was no match";
3407 res = US"was an exclude match";
3410 res = US"was an IP address that did not match";
3413 res = US"were no IP addresses that did not match";
3416 debug_printf("=> but we are not accepting this block class because\n");
3417 debug_printf("=> there %s for %s%c%s\n",
3419 ((match_type & MT_ALL) == 0)? "" : "=",
3420 bitmask? '&' : '=', iplist);
3426 /* Either there was no IP list, or the record matched, implying that the
3427 domain is on the list. We now want to find a corresponding TXT record. If an
3428 alternate domain is specified for the TXT record, call this function
3429 recursively to look that up; this has the side effect of re-checking that
3430 there is indeed an A record at the alternate domain. */
3432 if (domain_txt != domain)
3433 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3434 FALSE, match_type, defer_return);
3436 /* If there is no alternate domain, look up a TXT record in the main domain
3437 if it has not previously been cached. */
3441 cb->text_set = TRUE;
3442 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3445 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3447 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3448 if (rr->type == T_TXT) break;
3451 int len = (rr->data)[0];
3452 if (len > 511) len = 127;
3453 store_pool = POOL_PERM;
3454 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3455 store_pool = old_pool;
3460 dnslist_value = addlist;
3461 dnslist_text = cb->text;
3465 /* There was a problem with the DNS lookup */
3467 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3469 log_write(L_dnslist_defer, LOG_MAIN,
3470 "DNS list lookup defer (probably timeout) for %s: %s", query,
3471 (defer_return == OK)? US"assumed in list" :
3472 (defer_return == FAIL)? US"assumed not in list" :
3473 US"returned DEFER");
3474 return defer_return;
3477 /* No entry was found in the DNS; continue for next domain */
3481 debug_printf("DNS lookup for %s failed\n", query);
3482 debug_printf("=> that means %s is not listed at %s\n",
3492 /*************************************************
3493 * Check host against DNS black lists *
3494 *************************************************/
3496 /* This function runs checks against a list of DNS black lists, until one
3497 matches. Each item on the list can be of the form
3499 domain=ip-address/key
3501 The domain is the right-most domain that is used for the query, for example,
3502 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3503 if the DNS lookup returns a matching IP address. Several addresses may be
3504 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3506 If no key is given, what is looked up in the domain is the inverted IP address
3507 of the current client host. If a key is given, it is used to construct the
3508 domain for the lookup. For example:
3510 dsn.rfc-ignorant.org/$sender_address_domain
3512 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3513 then we check for a TXT record for an error message, and if found, save its
3514 value in $dnslist_text. We also cache everything in a tree, to optimize
3517 The TXT record is normally looked up in the same domain as the A record, but
3518 when many lists are combined in a single DNS domain, this will not be a very
3519 specific message. It is possible to specify a different domain for looking up
3520 TXT records; this is given before the main domain, comma-separated. For
3523 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3524 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3526 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3528 Note: an address for testing RBL is 192.203.178.39
3529 Note: an address for testing DUL is 192.203.178.4
3530 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3533 listptr the domain/address/data list
3535 Returns: OK successful lookup (i.e. the address is on the list), or
3536 lookup deferred after +include_unknown
3537 FAIL name not found, or no data found for the given type, or
3538 lookup deferred after +exclude_unknown (default)
3539 DEFER lookup failure, if +defer_unknown was set
3543 verify_check_dnsbl(uschar **listptr)
3546 int defer_return = FAIL;
3547 uschar *list = *listptr;
3550 uschar buffer[1024];
3551 uschar revadd[128]; /* Long enough for IPv6 address */
3553 /* Indicate that the inverted IP address is not yet set up */
3557 /* In case this is the first time the DNS resolver is being used. */
3559 dns_init(FALSE, FALSE);
3561 /* Loop through all the domains supplied, until something matches */
3563 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3566 BOOL bitmask = FALSE;
3573 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3575 /* Deal with special values that change the behaviour on defer */
3577 if (domain[0] == '+')
3579 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3580 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3581 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3583 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3588 /* See if there's explicit data to be looked up */
3590 key = Ustrchr(domain, '/');
3591 if (key != NULL) *key++ = 0;
3593 /* See if there's a list of addresses supplied after the domain name. This is
3594 introduced by an = or a & character; if preceded by = we require all matches
3595 and if preceded by ! we invert the result. */
3597 iplist = Ustrchr(domain, '=');
3601 iplist = Ustrchr(domain, '&');
3604 if (iplist != NULL) /* Found either = or & */
3606 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3608 match_type |= MT_NOT;
3612 *iplist++ = 0; /* Terminate domain, move on */
3614 /* If we found = (bitmask == FALSE), check for == or =& */
3616 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3618 bitmask = *iplist++ == '&';
3619 match_type |= MT_ALL;
3623 /* If there is a comma in the domain, it indicates that a second domain for
3624 looking up TXT records is provided, before the main domain. Otherwise we must
3625 set domain_txt == domain. */
3627 domain_txt = domain;
3628 comma = Ustrchr(domain, ',');
3635 /* Check that what we have left is a sensible domain name. There is no reason
3636 why these domains should in fact use the same syntax as hosts and email
3637 domains, but in practice they seem to. However, there is little point in
3638 actually causing an error here, because that would no doubt hold up incoming
3639 mail. Instead, I'll just log it. */
3641 for (s = domain; *s != 0; s++)
3643 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3645 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3646 "strange characters - is this right?", domain);
3651 /* Check the alternate domain if present */
3653 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3655 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3657 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3658 "strange characters - is this right?", domain_txt);
3663 /* If there is no key string, construct the query by adding the domain name
3664 onto the inverted host address, and perform a single DNS lookup. */
3668 if (sender_host_address == NULL) return FAIL; /* can never match */
3669 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3670 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3671 iplist, bitmask, match_type, defer_return);
3674 dnslist_domain = string_copy(domain_txt);
3675 dnslist_matched = string_copy(sender_host_address);
3676 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3677 sender_host_address, dnslist_domain);
3679 if (rc != FAIL) return rc; /* OK or DEFER */
3682 /* If there is a key string, it can be a list of domains or IP addresses to
3683 be concatenated with the main domain. */
3690 uschar keybuffer[256];
3691 uschar keyrevadd[128];
3693 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3694 sizeof(keybuffer))) != NULL)
3696 uschar *prepend = keydomain;
3698 if (string_is_ip_address(keydomain, NULL) != 0)
3700 invert_address(keyrevadd, keydomain);
3701 prepend = keyrevadd;
3704 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3705 bitmask, match_type, defer_return);
3709 dnslist_domain = string_copy(domain_txt);
3710 dnslist_matched = string_copy(keydomain);
3711 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3712 keydomain, dnslist_domain);
3716 /* If the lookup deferred, remember this fact. We keep trying the rest
3717 of the list to see if we get a useful result, and if we don't, we return
3718 DEFER at the end. */
3720 if (rc == DEFER) defer = TRUE;
3721 } /* continue with next keystring domain/address */
3723 if (defer) return DEFER;
3725 } /* continue with next dnsdb outer domain */
3732 /* End of verify.c */