1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 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() */
42 static uschar cutthrough_response(char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 cache_record = dbfn_read_with_length(dbm_file, key, &length);
73 if (cache_record == NULL)
75 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
79 /* We treat a record as "negative" if its result field is not positive, or if
80 it is a domain record and the postmaster field is negative. */
82 negative = cache_record->result != ccache_accept ||
83 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
84 expire = negative? negative_expire : positive_expire;
87 if (now - cache_record->time_stamp > expire)
89 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
93 /* If this is a non-reject domain record, check for the obsolete format version
94 that doesn't have the postmaster and random timestamps, by looking at the
95 length. If so, copy it to a new-style block, replicating the record's
96 timestamp. Then check the additional timestamps. (There's no point wasting
97 effort if connections are rejected.) */
99 if (type[0] == 'd' && cache_record->result != ccache_reject)
101 if (length == sizeof(dbdata_callout_cache_obs))
103 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
104 memcpy(new, cache_record, length);
105 new->postmaster_stamp = new->random_stamp = new->time_stamp;
109 if (now - cache_record->postmaster_stamp > expire)
110 cache_record->postmaster_result = ccache_unknown;
112 if (now - cache_record->random_stamp > expire)
113 cache_record->random_result = ccache_unknown;
116 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
122 /* Check the callout cache.
123 Options * pm_mailfrom may be modified by cache partial results.
125 Return: TRUE if result found
129 cached_callout_lookup(address_item * addr, uschar * address_key,
130 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
131 int * yield, uschar ** failure_ptr,
132 dbdata_callout_cache * new_domain_record, int * old_domain_res)
134 int options = *opt_ptr;
136 open_db *dbm_file = NULL;
138 /* Open the callout cache database, it it exists, for reading only at this
139 stage, unless caching has been disabled. */
141 if (options & vopt_callout_no_cache)
143 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
145 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
147 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
151 /* If a cache database is available see if we can avoid the need to do an
152 actual callout by making use of previously-obtained data. */
154 dbdata_callout_cache_address * cache_address_record;
155 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
156 addr->domain, US"domain",
157 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
159 /* If an unexpired cache record was found for this domain, see if the callout
160 process can be short-circuited. */
164 /* In most cases, if an early command (up to and including MAIL FROM:<>)
165 was rejected, there is no point carrying on. The callout fails. However, if
166 we are doing a recipient verification with use_sender or use_postmaster
167 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
168 will be using a non-empty sender. We have to remember this situation so as
169 not to disturb the cached domain value if this whole verification succeeds
170 (we don't want it turning into "accept"). */
172 *old_domain_res = cache_record->result;
174 if ( cache_record->result == ccache_reject
175 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
177 setflag(addr, af_verify_nsfail);
179 debug_printf("callout cache: domain gave initial rejection, or "
180 "does not accept HELO or MAIL FROM:<>\n");
181 setflag(addr, af_verify_nsfail);
182 addr->user_message = US"(result of an earlier callout reused).";
184 *failure_ptr = US"mail";
185 dbfn_close(dbm_file);
189 /* If a previous check on a "random" local part was accepted, we assume
190 that the server does not do any checking on local parts. There is therefore
191 no point in doing the callout, because it will always be successful. If a
192 random check previously failed, arrange not to do it again, but preserve
193 the data in the new record. If a random check is required but hasn't been
194 done, skip the remaining cache processing. */
196 if (options & vopt_callout_random) switch(cache_record->random_result)
200 debug_printf("callout cache: domain accepts random addresses\n");
201 dbfn_close(dbm_file);
202 return TRUE; /* Default yield is OK */
206 debug_printf("callout cache: domain rejects random addresses\n");
207 *opt_ptr = options & ~vopt_callout_random;
208 new_domain_record->random_result = ccache_reject;
209 new_domain_record->random_stamp = cache_record->random_stamp;
214 debug_printf("callout cache: need to check random address handling "
215 "(not cached or cache expired)\n");
216 dbfn_close(dbm_file);
220 /* If a postmaster check is requested, but there was a previous failure,
221 there is again no point in carrying on. If a postmaster check is required,
222 but has not been done before, we are going to have to do a callout, so skip
223 remaining cache processing. */
227 if (cache_record->postmaster_result == ccache_reject)
229 setflag(addr, af_verify_pmfail);
231 debug_printf("callout cache: domain does not accept "
232 "RCPT TO:<postmaster@domain>\n");
234 *failure_ptr = US"postmaster";
235 setflag(addr, af_verify_pmfail);
236 addr->user_message = US"(result of earlier verification reused).";
237 dbfn_close(dbm_file);
240 if (cache_record->postmaster_result == ccache_unknown)
243 debug_printf("callout cache: need to check RCPT "
244 "TO:<postmaster@domain> (not cached or cache expired)\n");
245 dbfn_close(dbm_file);
249 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
250 postmaster check if the address itself has to be checked. Also ensure
251 that the value in the cache record is preserved (with its old timestamp).
254 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
255 "TO:<postmaster@domain>\n");
257 new_domain_record->postmaster_result = ccache_accept;
258 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
262 /* We can't give a result based on information about the domain. See if there
263 is an unexpired cache record for this specific address (combined with the
264 sender address if we are doing a recipient callout with a non-empty sender).
267 if (!(cache_address_record = (dbdata_callout_cache_address *)
268 get_callout_cache_record(dbm_file, address_key, US"address",
269 callout_cache_positive_expire, callout_cache_negative_expire)))
271 dbfn_close(dbm_file);
275 if (cache_address_record->result == ccache_accept)
278 debug_printf("callout cache: address record is positive\n");
283 debug_printf("callout cache: address record is negative\n");
284 addr->user_message = US"Previous (cached) callout verification failure";
285 *failure_ptr = US"recipient";
289 /* Close the cache database while we actually do the callout for real. */
291 dbfn_close(dbm_file);
298 /* Write results to callout cache
301 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
302 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
305 open_db *dbm_file = NULL;
307 /* If we get here with done == TRUE, a successful callout happened, and yield
308 will be set OK or FAIL according to the response to the RCPT command.
309 Otherwise, we looped through the hosts but couldn't complete the business.
310 However, there may be domain-specific information to cache in both cases.
312 The value of the result field in the new_domain record is ccache_unknown if
313 there was an error before or with MAIL FROM:, and errno was not zero,
314 implying some kind of I/O error. We don't want to write the cache in that case.
315 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
317 if (dom_rec->result != ccache_unknown)
318 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
320 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
324 (void)dbfn_write(dbm_file, domain, dom_rec,
325 (int)sizeof(dbdata_callout_cache));
326 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
327 " result=%d postmaster=%d random=%d\n",
330 dom_rec->postmaster_result,
331 dom_rec->random_result);
334 /* If a definite result was obtained for the callout, cache it unless caching
337 if (done && addr_rec->result != ccache_unknown)
340 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
343 HDEBUG(D_verify) debug_printf("no callout cache available\n");
347 (void)dbfn_write(dbm_file, address_key, addr_rec,
348 (int)sizeof(dbdata_callout_cache_address));
349 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
350 addr_rec->result == ccache_accept ? "positive" : "negative",
355 if (dbm_file) dbfn_close(dbm_file);
359 /* Cutthrough-multi. If the existing cached cutthrough connection matches
360 the one we would make for a subsequent recipient, use it. Send the RCPT TO
361 and check the result, nonpipelined as it may be wanted immediately for
362 recipient-verification.
364 It seems simpler to deal with this case separately from the main callout loop.
365 We will need to remember it has sent, or not, so that rcpt-acl tail code
366 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
368 Return: TRUE for a definitive result for the recipient
371 cutthrough_multi(address_item * addr, host_item * host_list,
372 transport_feedback * tf, int * yield)
377 if (addr->transport == cutthrough.addr.transport)
378 for (host = host_list; host; host = host->next)
379 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
385 deliver_host = host->name;
386 deliver_host_address = host->address;
387 deliver_host_port = host->port;
388 deliver_domain = addr->domain;
389 transport_name = addr->transport->name;
391 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
393 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
395 !smtp_get_port(tf->port, addr, &port, US"callout"))
396 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
399 if ( ( interface == cutthrough.interface
401 && cutthrough.interface
402 && Ustrcmp(interface, cutthrough.interface) == 0
404 && port == cutthrough.host.port
407 uschar * resp = NULL;
409 /* Match! Send the RCPT TO, set done from the response */
411 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
412 transport_rcpt_address(addr,
413 addr->transport->rcpt_include_affixes)) >= 0 &&
414 cutthrough_response('2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
416 /* This would go horribly wrong if a callout fail was ignored by ACL.
417 We punt by abandoning cutthrough on a reject, like the
422 address_item * na = store_get(sizeof(address_item));
423 *na = cutthrough.addr;
424 cutthrough.addr = *addr;
425 cutthrough.addr.host_used = &cutthrough.host;
426 cutthrough.addr.next = na;
432 cancel_cutthrough_connection("recipient rejected");
433 if (!resp || errno == ETIMEDOUT)
435 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
440 Ustrcpy(resp, US"connection dropped");
443 string_sprintf("response to \"%s\" from %s [%s] was: %s",
444 big_buffer, host->name, host->address,
445 string_printing(resp));
448 string_sprintf("Callout verification failed:\n%s", resp);
450 /* Hard rejection ends the process */
452 if (resp[0] == '5') /* Address rejected */
460 break; /* host_list */
463 cancel_cutthrough_connection("incompatible connection");
468 /*************************************************
469 * Do callout verification for an address *
470 *************************************************/
472 /* This function is called from verify_address() when the address has routed to
473 a host list, and a callout has been requested. Callouts are expensive; that is
474 why a cache is used to improve the efficiency.
477 addr the address that's been routed
478 host_list the list of hosts to try
479 tf the transport feedback block
481 ifstring "interface" option from transport, or NULL
482 portstring "port" option from transport, or NULL
483 protocolstring "protocol" option from transport, or NULL
484 callout the per-command callout timeout
485 callout_overall the overall callout timeout (if < 0 use 4*callout)
486 callout_connect the callout connection timeout (if < 0 use callout)
487 options the verification options - these bits are used:
488 vopt_is_recipient => this is a recipient address
489 vopt_callout_no_cache => don't use callout cache
490 vopt_callout_fullpm => if postmaster check, do full one
491 vopt_callout_random => do the "random" thing
492 vopt_callout_recipsender => use real sender for recipient
493 vopt_callout_recippmaster => use postmaster for recipient
494 se_mailfrom MAIL FROM address for sender verify; NULL => ""
495 pm_mailfrom if non-NULL, do the postmaster check with this sender
497 Returns: OK/FAIL/DEFER
501 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
502 int callout, int callout_overall, int callout_connect, int options,
503 uschar *se_mailfrom, uschar *pm_mailfrom)
506 int old_domain_cache_result = ccache_accept;
509 uschar *from_address;
510 uschar *random_local_part = NULL;
511 const uschar *save_deliver_domain = deliver_domain;
512 uschar **failure_ptr = options & vopt_is_recipient
513 ? &recipient_verify_failure : &sender_verify_failure;
514 dbdata_callout_cache new_domain_record;
515 dbdata_callout_cache_address new_address_record;
516 time_t callout_start_time;
518 new_domain_record.result = ccache_unknown;
519 new_domain_record.postmaster_result = ccache_unknown;
520 new_domain_record.random_result = ccache_unknown;
522 memset(&new_address_record, 0, sizeof(new_address_record));
524 /* For a recipient callout, the key used for the address cache record must
525 include the sender address if we are using the real sender in the callout,
526 because that may influence the result of the callout. */
528 if (options & vopt_is_recipient)
529 if (options & vopt_callout_recipsender)
531 from_address = sender_address;
532 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
533 if (cutthrough.delivery) options |= vopt_callout_no_cache;
535 else if (options & vopt_callout_recippmaster)
537 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
538 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
539 qualify_domain_sender);
544 address_key = addr->address;
547 /* For a sender callout, we must adjust the key if the mailfrom address is not
552 from_address = se_mailfrom ? se_mailfrom : US"";
553 address_key = *from_address
554 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
557 if (cached_callout_lookup(addr, address_key, from_address,
558 &options, &pm_mailfrom, &yield, failure_ptr,
559 &new_domain_record, &old_domain_cache_result))
562 if (!addr->transport)
564 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
566 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
567 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
568 addr->transport->name, addr->transport->driver_name);
571 smtp_transport_options_block *ob =
572 (smtp_transport_options_block *)addr->transport->options_block;
575 /* The information wasn't available in the cache, so we have to do a real
576 callout and save the result in the cache for next time, unless no_cache is set,
577 or unless we have a previously cached negative random result. If we are to test
578 with a random local part, ensure that such a local part is available. If not,
579 log the fact, but carry on without randomising. */
581 if (options & vopt_callout_random && callout_random_local_part)
582 if (!(random_local_part = expand_string(callout_random_local_part)))
583 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
584 "callout_random_local_part: %s", expand_string_message);
586 /* Default the connect and overall callout timeouts if not set, and record the
587 time we are starting so that we can enforce it. */
589 if (callout_overall < 0) callout_overall = 4 * callout;
590 if (callout_connect < 0) callout_connect = callout;
591 callout_start_time = time(NULL);
593 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
594 output because a callout might take some time. When PIPELINING is active and
595 there are many recipients, the total time for doing lots of callouts can add up
596 and cause the client to time out. So in this case we forgo the PIPELINING
599 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
601 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
602 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
604 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
605 and we are holding a cutthrough conn open, we can just append the rcpt to
606 that conn for verification purposes (and later delivery also). Simplest
607 coding means skipping this whole loop and doing the append separately. */
609 /* Can we re-use an open cutthrough connection? */
610 if ( cutthrough.fd >= 0
611 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
612 == vopt_callout_recipsender
613 && !random_local_part
616 done = cutthrough_multi(addr, host_list, tf, &yield);
618 /* If we did not use a cached connection, make connections to the hosts
619 and do real callouts. The list of hosts is passed in as an argument. */
621 for (host = host_list; host && !done; host = host->next)
625 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
627 uschar responsebuffer[4096];
631 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
636 /* Check the overall callout timeout */
638 if (time(NULL) - callout_start_time >= callout_overall)
640 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
644 /* Set IPv4 or IPv6 */
646 host_af = Ustrchr(host->address, ':') == NULL ? AF_INET : AF_INET6;
648 /* Expand and interpret the interface and port strings. The latter will not
649 be used if there is a host-specific port (e.g. from a manualroute router).
650 This has to be delayed till now, because they may expand differently for
651 different hosts. If there's a failure, log it, but carry on with the
654 deliver_host = host->name;
655 deliver_host_address = host->address;
656 deliver_host_port = host->port;
657 deliver_domain = addr->domain;
658 transport_name = addr->transport->name;
660 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
662 || !smtp_get_port(tf->port, addr, &port, US"callout")
664 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
669 sx.host_af = host_af,
671 sx.interface = interface;
672 sx.helo_data = tf->helo_data;
673 sx.tblock = addr->transport;
675 tls_retry_connection:
676 /* Set the address state so that errors are recorded in it */
678 addr->transport_return = PENDING_DEFER;
679 ob->connect_timeout = callout_connect;
680 ob->command_timeout = callout;
682 /* Get the channel set up ready for a message (MAIL FROM being the next
683 SMTP command to send. If we tried TLS but it failed, try again without
686 if ( (yield = smtp_setup_conn(&sx, FALSE, TRUE)) == DEFER
687 && addr->basic_errno == ERRNO_TLSFAILURE
688 && ob->tls_tempfail_tryclear
689 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
692 log_write(0, LOG_MAIN, "TLS session failure:"
693 " callout unencrypted to %s [%s] (not in hosts_require_tls)",
694 host->name, host->address);
695 yield = smtp_setup_conn(&sx, TRUE, TRUE);
699 if (addr->message) addr->message = string_sprintf("%s [%s] %s",
700 host->name, host->address, addr->message);
701 errno = addr->basic_errno;
702 transport_name = NULL;
703 deliver_host = deliver_host_address = NULL;
704 deliver_domain = save_deliver_domain;
706 /* Failure to accept HELO is cached; this blocks the whole domain for all
707 senders. I/O errors and defer responses are not cached. */
709 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
711 setflag(addr, af_verify_nsfail);
712 new_domain_record.result = ccache_reject;
720 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
721 the AUTH info for logging */
723 addr->authenticator = client_authenticator;
724 addr->auth_id = client_authenticated_id;
726 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
729 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob);
733 addr->auth_sndr = client_authenticated_sender;
735 /* Send the MAIL command */
738 (smtp_write_command(&sx.outblock, FALSE,
740 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
741 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
744 "MAIL FROM:<%s>%s%s\r\n",
747 options & vopt_is_recipient && sx.peer_offered & PEER_OFFERED_SIZE
748 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition)
752 && smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
756 deliver_host = deliver_host_address = NULL;
757 deliver_domain = save_deliver_domain;
759 /* If the host does not accept MAIL FROM:<>, arrange to cache this
760 information, but again, don't record anything for an I/O error or a defer. Do
761 not cache rejections of MAIL when a non-empty sender has been used, because
762 that blocks the whole domain for all senders. */
766 *failure_ptr = US"mail"; /* At or before MAIL */
767 if (errno == 0 && responsebuffer[0] == '5')
769 setflag(addr, af_verify_nsfail);
770 if (from_address[0] == 0)
771 new_domain_record.result = ccache_reject_mfnull;
775 /* Otherwise, proceed to check a "random" address (if required), then the
776 given address, and the postmaster address (if required). Between each check,
777 issue RSET, because some servers accept only one recipient after MAIL
780 Before doing this, set the result in the domain cache record to "accept",
781 unless its previous value was ccache_reject_mfnull. In that case, the domain
782 rejects MAIL FROM:<> and we want to continue to remember that. When that is
783 the case, we have got here only in the case of a recipient verification with
784 a non-null sender. */
788 const uschar * rcpt_domain = addr->domain;
791 uschar * errstr = NULL;
792 if ( testflag(addr, af_utf8_downcvt)
793 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
797 addr->message = errstr;
798 errno = ERRNO_EXPANDFAIL;
799 setflag(addr, af_verify_nsfail);
801 rcpt_domain = US""; /*XXX errorhandling! */
805 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
806 ? ccache_reject_mfnull : ccache_accept;
808 /* Do the random local part check first */
810 if (random_local_part)
812 uschar randombuffer[1024];
814 smtp_write_command(&sx.outblock, FALSE,
815 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
817 smtp_read_response(&sx.inblock, randombuffer,
818 sizeof(randombuffer), '2', callout);
820 /* Remember when we last did a random test */
822 new_domain_record.random_stamp = time(NULL);
824 /* If accepted, we aren't going to do any further tests below. */
827 new_domain_record.random_result = ccache_accept;
829 /* Otherwise, cache a real negative response, and get back to the right
830 state to send RCPT. Unless there's some problem such as a dropped
831 connection, we expect to succeed, because the commands succeeded above.
832 However, some servers drop the connection after responding to an
833 invalid recipient, so on (any) error we drop and remake the connection.
838 /* This would be ok for 1st rcpt a cutthrough, but no way to
839 handle a subsequent. So refuse to support any */
840 cancel_cutthrough_connection("random-recipient");
842 if (randombuffer[0] == '5')
843 new_domain_record.random_result = ccache_reject;
846 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
847 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
850 smtp_write_command(&sx.outblock, FALSE,
852 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
853 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
856 "MAIL FROM:<%s>\r\n",
857 from_address) >= 0 &&
858 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
864 debug_printf("problem after random/rset/mfrom; reopen conn\n");
865 random_local_part = NULL;
867 tls_close(FALSE, TRUE);
869 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
870 (void)close(sx.inblock.sock);
871 #ifndef DISABLE_EVENT
872 (void) event_raise(addr->transport->event_action,
873 US"tcp:close", NULL);
875 goto tls_retry_connection;
878 else done = FALSE; /* Some timeout/connection problem */
881 /* If the host is accepting all local parts, as determined by the "random"
882 check, we don't need to waste time doing any further checking. */
884 if (new_domain_record.random_result != ccache_accept && done)
886 /* Get the rcpt_include_affixes flag from the transport if there is one,
887 but assume FALSE if there is not. */
889 uschar * rcpt = transport_rcpt_address(addr,
890 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
893 /*XXX should the conversion be moved into transport_rcpt_address() ? */
894 if ( testflag(addr, af_utf8_downcvt)
895 && !(rcpt = string_address_utf8_to_alabel(rcpt, NULL))
898 errno = ERRNO_EXPANDFAIL;
899 *failure_ptr = US"recipient";
906 smtp_write_command(&sx.outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
908 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
912 new_address_record.result = ccache_accept;
913 else if (errno == 0 && responsebuffer[0] == '5')
915 *failure_ptr = US"recipient";
916 new_address_record.result = ccache_reject;
919 /* Do postmaster check if requested; if a full check is required, we
920 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
922 if (done && pm_mailfrom)
924 /* Could possibly shift before main verify, just above, and be ok
925 for cutthrough. But no way to handle a subsequent rcpt, so just
927 cancel_cutthrough_connection("postmaster verify");
928 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
931 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
932 smtp_read_response(&sx.inblock, responsebuffer,
933 sizeof(responsebuffer), '2', callout) &&
935 smtp_write_command(&sx.outblock, FALSE,
936 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
937 smtp_read_response(&sx.inblock, responsebuffer,
938 sizeof(responsebuffer), '2', callout) &&
940 /* First try using the current domain */
943 smtp_write_command(&sx.outblock, FALSE,
944 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
945 smtp_read_response(&sx.inblock, responsebuffer,
946 sizeof(responsebuffer), '2', callout)
951 /* If that doesn't work, and a full check is requested,
952 try without the domain. */
955 (options & vopt_callout_fullpm) != 0 &&
956 smtp_write_command(&sx.outblock, FALSE,
957 "RCPT TO:<postmaster>\r\n") >= 0 &&
958 smtp_read_response(&sx.inblock, responsebuffer,
959 sizeof(responsebuffer), '2', callout)
962 /* Sort out the cache record */
964 new_domain_record.postmaster_stamp = time(NULL);
967 new_domain_record.postmaster_result = ccache_accept;
968 else if (errno == 0 && responsebuffer[0] == '5')
970 *failure_ptr = US"postmaster";
971 setflag(addr, af_verify_pmfail);
972 new_domain_record.postmaster_result = ccache_reject;
975 } /* Random not accepted */
976 } /* MAIL FROM: accepted */
978 /* For any failure of the main check, other than a negative response, we just
979 close the connection and carry on. We can identify a negative response by the
980 fact that errno is zero. For I/O errors it will be non-zero
982 Set up different error texts for logging and for sending back to the caller
983 as an SMTP response. Log in all cases, using a one-line format. For sender
984 callouts, give a full response to the caller, but for recipient callouts,
985 don't give the IP address because this may be an internal host whose identity
986 is not to be widely broadcast. */
989 if (!done) switch(errno)
992 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
993 sx.send_quit = FALSE;
999 extern int acl_where; /* src/acl.c */
1001 addr->message = string_sprintf(
1002 "response to \"EHLO\" from %s [%s] did not include SMTPUTF8",
1003 host->name, host->address);
1004 addr->user_message = acl_where == ACL_WHERE_RCPT
1005 ? US"533 no support for internationalised mailbox name"
1006 : US"550 mailbox unavailable";
1013 sx.send_quit = FALSE;
1017 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1020 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1021 big_buffer, host->name, host->address,
1022 string_printing(responsebuffer));
1024 addr->user_message = options & vopt_is_recipient
1025 ? string_sprintf("Callout verification failed:\n%s", responsebuffer)
1026 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1027 host->address, big_buffer, responsebuffer);
1029 /* Hard rejection ends the process */
1031 if (responsebuffer[0] == '5') /* Address rejected */
1039 /* End the SMTP conversation and close the connection. */
1041 /* Cutthrough - on a successful connect and recipient-verify with
1042 use-sender and we are 1st rcpt and have no cutthrough conn so far
1043 here is where we want to leave the conn open */
1044 if ( cutthrough.delivery
1048 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1049 == vopt_callout_recipsender
1050 && !random_local_part
1052 && cutthrough.fd < 0
1056 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1058 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1059 cutthrough.nrcpt = 1;
1060 cutthrough.interface = interface;
1061 cutthrough.host = *host;
1062 cutthrough.addr = *addr; /* Save the address_item for later logging */
1063 cutthrough.addr.next = NULL;
1064 cutthrough.addr.host_used = &cutthrough.host;
1066 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1068 ctblock.buffer = ctbuffer;
1069 ctblock.buffersize = sizeof(ctbuffer);
1070 ctblock.ptr = ctbuffer;
1071 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1072 ctblock.sock = cutthrough.fd;
1076 /* Ensure no cutthrough on multiple address verifies */
1077 if (options & vopt_callout_recipsender)
1078 cancel_cutthrough_connection("not usable for cutthrough");
1081 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1083 /* Wait a short time for response, and discard it */
1084 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
1088 if (sx.inblock.sock >= 0)
1091 tls_close(FALSE, TRUE);
1093 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1094 (void)close(sx.inblock.sock);
1095 sx.inblock.sock = sx.outblock.sock = -1;
1096 #ifndef DISABLE_EVENT
1097 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1102 } /* Loop through all hosts, while !done */
1105 /* If we get here with done == TRUE, a successful callout happened, and yield
1106 will be set OK or FAIL according to the response to the RCPT command.
1107 Otherwise, we looped through the hosts but couldn't complete the business.
1108 However, there may be domain-specific information to cache in both cases. */
1110 if (!(options & vopt_callout_no_cache))
1111 cache_callout_write(&new_domain_record, addr->domain,
1112 done, &new_address_record, address_key);
1114 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1115 temporary error. If there was only one host, and a response was received, leave
1116 it alone if supplying details. Otherwise, give a generic response. */
1120 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1121 options & vopt_is_recipient ? "recipient" : "sender");
1124 addr->message = host_list->next || !addr->message
1125 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1127 addr->user_message = smtp_return_error_details
1128 ? string_sprintf("%s for <%s>.\n"
1129 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1130 "they may be permanently unreachable from this server. In the latter case,\n%s",
1131 dullmsg, addr->address,
1132 options & vopt_is_recipient
1133 ? "the address will never be accepted."
1134 : "you need to change the address or create an MX record for its domain\n"
1135 "if it is supposed to be generally accessible from the Internet.\n"
1136 "Talk to your mail administrator for details.")
1139 /* Force a specific error code */
1141 addr->basic_errno = ERRNO_CALLOUTDEFER;
1144 /* Come here from within the cache-reading code on fast-track exit. */
1147 tls_modify_variables(&tls_in);
1153 /* Called after recipient-acl to get a cutthrough connection open when
1154 one was requested and a recipient-verify wasn't subsequently done.
1157 open_cutthrough_connection( address_item * addr )
1162 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1163 /* We must use a copy of the address for verification, because it might
1167 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1168 rcpt_count > 1 ? "more" : "start");
1169 rc = verify_address(&addr2, NULL,
1170 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1171 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1173 addr->message = addr2.message;
1174 addr->user_message = addr2.user_message;
1175 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1181 /* Send given number of bytes from the buffer */
1183 cutthrough_send(int n)
1185 if(cutthrough.fd < 0)
1190 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1192 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1195 transport_count += n;
1196 ctblock.ptr= ctblock.buffer;
1200 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1207 _cutthrough_puts(uschar * cp, int n)
1211 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1212 if(!cutthrough_send(ctblock.buffersize))
1215 *ctblock.ptr++ = *cp++;
1220 /* Buffered output of counted data block. Return boolean success */
1222 cutthrough_puts(uschar * cp, int n)
1224 if (cutthrough.fd < 0) return TRUE;
1225 if (_cutthrough_puts(cp, n)) return TRUE;
1226 cancel_cutthrough_connection("transmit failed");
1232 _cutthrough_flush_send(void)
1234 int n= ctblock.ptr-ctblock.buffer;
1237 if(!cutthrough_send(n))
1243 /* Send out any bufferred output. Return boolean success. */
1245 cutthrough_flush_send(void)
1247 if (_cutthrough_flush_send()) return TRUE;
1248 cancel_cutthrough_connection("transmit failed");
1254 cutthrough_put_nl(void)
1256 return cutthrough_puts(US"\r\n", 2);
1260 /* Get and check response from cutthrough target */
1262 cutthrough_response(char expect, uschar ** copy, int timeout)
1264 smtp_inblock inblock;
1265 uschar inbuffer[4096];
1266 uschar responsebuffer[4096];
1268 inblock.buffer = inbuffer;
1269 inblock.buffersize = sizeof(inbuffer);
1270 inblock.ptr = inbuffer;
1271 inblock.ptrend = inbuffer;
1272 inblock.sock = cutthrough.fd;
1273 /* this relies on (inblock.sock == tls_out.active) */
1274 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1275 cancel_cutthrough_connection("target timeout on read");
1280 *copy = cp = string_copy(responsebuffer);
1281 /* Trim the trailing end of line */
1282 cp += Ustrlen(responsebuffer);
1283 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1284 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1287 return responsebuffer[0];
1291 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1293 cutthrough_predata(void)
1295 if(cutthrough.fd < 0)
1298 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1299 cutthrough_puts(US"DATA\r\n", 6);
1300 cutthrough_flush_send();
1302 /* Assume nothing buffered. If it was it gets ignored. */
1303 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1307 /* fd and tctx args only to match write_chunk() */
1309 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1312 while(s && (s2 = Ustrchr(s, '\n')))
1314 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1322 /* Buffered send of headers. Return success boolean. */
1323 /* Expands newlines to wire format (CR,NL). */
1324 /* Also sends header-terminating blank line. */
1326 cutthrough_headers_send(void)
1330 if(cutthrough.fd < 0)
1333 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1334 but having a separate buffered-output function (for now)
1336 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1338 tctx.tblock = cutthrough.addr.transport;
1339 tctx.addr = &cutthrough.addr;
1340 tctx.check_string = US".";
1341 tctx.escape_string = US"..";
1342 tctx.options = topt_use_crlf;
1344 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1347 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1353 close_cutthrough_connection(const char * why)
1355 if(cutthrough.fd >= 0)
1357 /* We could be sending this after a bunch of data, but that is ok as
1358 the only way to cancel the transfer in dataphase is to drop the tcp
1359 conn before the final dot.
1361 ctblock.ptr = ctbuffer;
1362 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1363 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1364 _cutthrough_flush_send();
1366 /* Wait a short time for response, and discard it */
1367 cutthrough_response('2', NULL, 1);
1370 tls_close(FALSE, TRUE);
1372 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1373 (void)close(cutthrough.fd);
1375 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1377 ctblock.ptr = ctbuffer;
1381 cancel_cutthrough_connection(const char * why)
1383 close_cutthrough_connection(why);
1384 cutthrough.delivery = FALSE;
1390 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1391 Log an OK response as a transmission.
1392 Close the connection.
1393 Return smtp response-class digit.
1396 cutthrough_finaldot(void)
1399 address_item * addr;
1400 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1402 /* Assume data finshed with new-line */
1403 if( !cutthrough_puts(US".", 1)
1404 || !cutthrough_put_nl()
1405 || !cutthrough_flush_send()
1407 return cutthrough.addr.message;
1409 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1410 for (addr = &cutthrough.addr; addr; addr = addr->next)
1412 addr->message = cutthrough.addr.message;
1416 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1417 close_cutthrough_connection("delivered");
1421 delivery_log(LOG_MAIN, addr, 0,
1422 US"tmp-reject from cutthrough after DATA:");
1426 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1427 US"rejected after DATA:");
1434 return cutthrough.addr.message;
1439 /*************************************************
1440 * Copy error to toplevel address *
1441 *************************************************/
1443 /* This function is used when a verify fails or defers, to ensure that the
1444 failure or defer information is in the original toplevel address. This applies
1445 when an address is redirected to a single new address, and the failure or
1446 deferral happens to the child address.
1449 vaddr the verify address item
1450 addr the final address item
1453 Returns: the value of YIELD
1457 copy_error(address_item *vaddr, address_item *addr, int yield)
1461 vaddr->message = addr->message;
1462 vaddr->user_message = addr->user_message;
1463 vaddr->basic_errno = addr->basic_errno;
1464 vaddr->more_errno = addr->more_errno;
1465 vaddr->prop.address_data = addr->prop.address_data;
1466 copyflag(vaddr, addr, af_pass_message);
1474 /**************************************************
1475 * printf that automatically handles TLS if needed *
1476 ***************************************************/
1478 /* This function is used by verify_address() as a substitute for all fprintf()
1479 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1480 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1481 that assumes that we always use the smtp_out FILE* when not using TLS or the
1482 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1483 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1487 f the candidate FILE* to write to
1488 format format string
1489 ... optional arguments
1495 static void PRINTF_FUNCTION(2,3)
1496 respond_printf(FILE *f, const char *format, ...)
1500 va_start(ap, format);
1501 if (smtp_out && (f == smtp_out))
1502 smtp_vprintf(format, ap);
1504 vfprintf(f, format, ap);
1510 /*************************************************
1511 * Verify an email address *
1512 *************************************************/
1514 /* This function is used both for verification (-bv and at other times) and
1515 address testing (-bt), which is indicated by address_test_mode being set.
1518 vaddr contains the address to verify; the next field in this block
1520 f if not NULL, write the result to this file
1521 options various option bits:
1522 vopt_fake_sender => this sender verify is not for the real
1523 sender (it was verify=sender=xxxx or an address from a
1524 header line) - rewriting must not change sender_address
1525 vopt_is_recipient => this is a recipient address, otherwise
1526 it's a sender address - this affects qualification and
1527 rewriting and messages from callouts
1528 vopt_qualify => qualify an unqualified address; else error
1529 vopt_expn => called from SMTP EXPN command
1530 vopt_success_on_redirect => when a new address is generated
1531 the verification instantly succeeds
1533 These ones are used by do_callout() -- the options variable
1536 vopt_callout_fullpm => if postmaster check, do full one
1537 vopt_callout_no_cache => don't use callout cache
1538 vopt_callout_random => do the "random" thing
1539 vopt_callout_recipsender => use real sender for recipient
1540 vopt_callout_recippmaster => use postmaster for recipient
1542 callout if > 0, specifies that callout is required, and gives timeout
1543 for individual commands
1544 callout_overall if > 0, gives overall timeout for the callout function;
1545 if < 0, a default is used (see do_callout())
1546 callout_connect the connection timeout for callouts
1547 se_mailfrom when callout is requested to verify a sender, use this
1548 in MAIL FROM; NULL => ""
1549 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1550 thing and use this as the sender address (may be "")
1552 routed if not NULL, set TRUE if routing succeeded, so we can
1553 distinguish between routing failed and callout failed
1555 Returns: OK address verified
1556 FAIL address failed to verify
1557 DEFER can't tell at present
1561 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1562 int callout_overall, int callout_connect, uschar *se_mailfrom,
1563 uschar *pm_mailfrom, BOOL *routed)
1566 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1567 BOOL expn = (options & vopt_expn) != 0;
1568 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1571 int verify_type = expn? v_expn :
1572 address_test_mode? v_none :
1573 options & vopt_is_recipient? v_recipient : v_sender;
1574 address_item *addr_list;
1575 address_item *addr_new = NULL;
1576 address_item *addr_remote = NULL;
1577 address_item *addr_local = NULL;
1578 address_item *addr_succeed = NULL;
1579 uschar **failure_ptr = options & vopt_is_recipient
1580 ? &recipient_verify_failure : &sender_verify_failure;
1581 uschar *ko_prefix, *cr;
1582 uschar *address = vaddr->address;
1583 uschar *save_sender;
1584 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1586 /* Clear, just in case */
1588 *failure_ptr = NULL;
1590 /* Set up a prefix and suffix for error message which allow us to use the same
1591 output statements both in EXPN mode (where an SMTP response is needed) and when
1592 debugging with an output file. */
1596 ko_prefix = US"553 ";
1599 else ko_prefix = cr = US"";
1601 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1603 if (parse_find_at(address) == NULL)
1605 if ((options & vopt_qualify) == 0)
1608 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1609 ko_prefix, address, cr);
1610 *failure_ptr = US"qualify";
1613 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1618 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1619 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1622 /* Rewrite and report on it. Clear the domain and local part caches - these
1623 may have been set by domains and local part tests during an ACL. */
1625 if (global_rewrite_rules != NULL)
1627 uschar *old = address;
1628 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1629 global_rewrite_rules, rewrite_existflags);
1632 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1633 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1634 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1638 /* If this is the real sender address, we must update sender_address at
1639 this point, because it may be referred to in the routers. */
1641 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1642 sender_address = address;
1644 /* If the address was rewritten to <> no verification can be done, and we have
1645 to return OK. This rewriting is permitted only for sender addresses; for other
1646 addresses, such rewriting fails. */
1648 if (address[0] == 0) return OK;
1650 /* Flip the legacy TLS-related variables over to the outbound set in case
1651 they're used in the context of a transport used by verification. Reset them
1652 at exit from this routine (so no returns allowed from here on). */
1654 tls_modify_variables(&tls_out);
1656 /* Save a copy of the sender address for re-instating if we change it to <>
1657 while verifying a sender address (a nice bit of self-reference there). */
1659 save_sender = sender_address;
1661 /* Observability variable for router/transport use */
1663 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1665 /* Update the address structure with the possibly qualified and rewritten
1666 address. Set it up as the starting address on the chain of new addresses. */
1668 vaddr->address = address;
1671 /* We need a loop, because an address can generate new addresses. We must also
1672 cope with generated pipes and files at the top level. (See also the code and
1673 comment in deliver.c.) However, it is usually the case that the router for
1674 user's .forward files has its verify flag turned off.
1676 If an address generates more than one child, the loop is used only when
1677 full_info is set, and this can only be set locally. Remote enquiries just get
1678 information about the top level address, not anything that it generated. */
1683 address_item *addr = addr_new;
1685 addr_new = addr->next;
1690 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1691 debug_printf("Considering %s\n", addr->address);
1694 /* Handle generated pipe, file or reply addresses. We don't get these
1695 when handling EXPN, as it does only one level of expansion. */
1697 if (testflag(addr, af_pfr))
1704 if (addr->address[0] == '>')
1706 allow = testflag(addr, af_allow_reply);
1707 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1711 allow = (addr->address[0] == '|')?
1712 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1713 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1716 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1717 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1718 "%s\n", addr->message);
1720 fprintf(f, "\n transport = %s\n", addr->transport->name);
1722 fprintf(f, " *** forbidden ***\n");
1727 /* Just in case some router parameter refers to it. */
1729 return_path = addr->prop.errors_address
1730 ? addr->prop.errors_address : sender_address;
1732 /* Split the address into domain and local part, handling the %-hack if
1733 necessary, and then route it. While routing a sender address, set
1734 $sender_address to <> because that is what it will be if we were trying to
1735 send a bounce to the sender. */
1737 if (routed) *routed = FALSE;
1738 if ((rc = deliver_split_address(addr)) == OK)
1740 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1741 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1742 &addr_succeed, verify_type);
1743 sender_address = save_sender; /* Put back the real sender */
1746 /* If routing an address succeeded, set the flag that remembers, for use when
1747 an ACL cached a sender verify (in case a callout fails). Then if routing set
1748 up a list of hosts or the transport has a host list, and the callout option
1749 is set, and we aren't in a host checking run, do the callout verification,
1750 and set another flag that notes that a callout happened. */
1754 if (routed) *routed = TRUE;
1757 transport_instance * tp;
1758 host_item * host_list = addr->host_list;
1760 /* Make up some data for use in the case where there is no remote
1763 transport_feedback tf = {
1764 NULL, /* interface (=> any) */
1765 US"smtp", /* port */
1766 US"smtp", /* protocol */
1768 US"$smtp_active_hostname", /* helo_data */
1769 FALSE, /* hosts_override */
1770 FALSE, /* hosts_randomize */
1771 FALSE, /* gethostbyname */
1772 TRUE, /* qualify_single */
1773 FALSE /* search_parents */
1776 /* If verification yielded a remote transport, we want to use that
1777 transport's options, so as to mimic what would happen if we were really
1778 sending a message to this address. */
1780 if ((tp = addr->transport) && !tp->info->local)
1782 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1784 /* If the transport has hosts and the router does not, or if the
1785 transport is configured to override the router's hosts, we must build a
1786 host list of the transport's hosts, and find the IP addresses */
1788 if (tf.hosts && (!host_list || tf.hosts_override))
1791 const uschar *save_deliver_domain = deliver_domain;
1792 uschar *save_deliver_localpart = deliver_localpart;
1794 host_list = NULL; /* Ignore the router's hosts */
1796 deliver_domain = addr->domain;
1797 deliver_localpart = addr->local_part;
1798 s = expand_string(tf.hosts);
1799 deliver_domain = save_deliver_domain;
1800 deliver_localpart = save_deliver_localpart;
1804 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1805 "\"%s\" in %s transport for callout: %s", tf.hosts,
1806 tp->name, expand_string_message);
1811 host_item *host, *nexthost;
1812 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1814 /* Just ignore failures to find a host address. If we don't manage
1815 to find any addresses, the callout will defer. Note that more than
1816 one address may be found for a single host, which will result in
1817 additional host items being inserted into the chain. Hence we must
1818 save the next host first. */
1820 flags = HOST_FIND_BY_A;
1821 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1822 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1824 for (host = host_list; host; host = nexthost)
1826 nexthost = host->next;
1827 if (tf.gethostbyname ||
1828 string_is_ip_address(host->name, NULL) != 0)
1829 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1832 dnssec_domains * dnssec_domains = NULL;
1833 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1835 smtp_transport_options_block * ob =
1836 (smtp_transport_options_block *) tp->options_block;
1837 dnssec_domains = &ob->dnssec;
1840 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1841 dnssec_domains, NULL, NULL);
1848 /* Can only do a callout if we have at least one host! If the callout
1849 fails, it will have set ${sender,recipient}_verify_failure. */
1853 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1854 if (host_checking && !host_checking_callout)
1857 debug_printf("... callout omitted by default when host testing\n"
1858 "(Use -bhc if you want the callouts to happen.)\n");
1863 deliver_set_expansions(addr);
1865 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1866 callout_connect, options, se_mailfrom, pm_mailfrom);
1871 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1872 "transport provided a host list\n");
1877 /* Otherwise, any failure is a routing failure */
1879 else *failure_ptr = US"route";
1881 /* A router may return REROUTED if it has set up a child address as a result
1882 of a change of domain name (typically from widening). In this case we always
1883 want to continue to verify the new child. */
1885 if (rc == REROUTED) continue;
1887 /* Handle hard failures */
1894 address_item *p = addr->parent;
1896 respond_printf(f, "%s%s %s", ko_prefix,
1897 full_info ? addr->address : address,
1898 address_test_mode ? "is undeliverable" : "failed to verify");
1899 if (!expn && admin_user)
1901 if (addr->basic_errno > 0)
1902 respond_printf(f, ": %s", strerror(addr->basic_errno));
1904 respond_printf(f, ": %s", addr->message);
1907 /* Show parents iff doing full info */
1909 if (full_info) while (p)
1911 respond_printf(f, "%s\n <-- %s", cr, p->address);
1914 respond_printf(f, "%s\n", cr);
1916 cancel_cutthrough_connection("routing hard fail");
1920 yield = copy_error(vaddr, addr, FAIL);
1928 else if (rc == DEFER)
1933 address_item *p = addr->parent;
1934 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1935 full_info? addr->address : address);
1936 if (!expn && admin_user)
1938 if (addr->basic_errno > 0)
1939 respond_printf(f, ": %s", strerror(addr->basic_errno));
1941 respond_printf(f, ": %s", addr->message);
1942 else if (addr->basic_errno <= 0)
1943 respond_printf(f, ": unknown error");
1946 /* Show parents iff doing full info */
1948 if (full_info) while (p)
1950 respond_printf(f, "%s\n <-- %s", cr, p->address);
1953 respond_printf(f, "%s\n", cr);
1955 cancel_cutthrough_connection("routing soft fail");
1959 yield = copy_error(vaddr, addr, DEFER);
1962 if (yield == OK) yield = DEFER;
1965 /* If we are handling EXPN, we do not want to continue to route beyond
1966 the top level (whose address is in "address"). */
1970 uschar *ok_prefix = US"250-";
1973 if (!addr_local && !addr_remote)
1974 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1976 respond_printf(f, "250 <%s>\r\n", address);
1980 address_item *addr2 = addr_new;
1981 addr_new = addr2->next;
1982 if (!addr_new) ok_prefix = US"250 ";
1983 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1989 /* Successful routing other than EXPN. */
1993 /* Handle successful routing when short info wanted. Otherwise continue for
1994 other (generated) addresses. Short info is the operational case. Full info
1995 can be requested only when debug_selector != 0 and a file is supplied.
1997 There is a conflict between the use of aliasing as an alternate email
1998 address, and as a sort of mailing list. If an alias turns the incoming
1999 address into just one address (e.g. J.Caesar->jc44) you may well want to
2000 carry on verifying the generated address to ensure it is valid when
2001 checking incoming mail. If aliasing generates multiple addresses, you
2002 probably don't want to do this. Exim therefore treats the generation of
2003 just a single new address as a special case, and continues on to verify the
2004 generated address. */
2006 if ( !full_info /* Stop if short info wanted AND */
2007 && ( ( !addr_new /* No new address OR */
2008 || addr_new->next /* More than one new address OR */
2009 || testflag(addr_new, af_pfr) /* New address is pfr */
2012 ( addr_new /* At least one new address AND */
2013 && success_on_redirect /* success_on_redirect is set */
2017 if (f) fprintf(f, "%s %s\n",
2018 address, address_test_mode ? "is deliverable" : "verified");
2020 /* If we have carried on to verify a child address, we want the value
2021 of $address_data to be that of the child */
2023 vaddr->prop.address_data = addr->prop.address_data;
2025 /* If stopped because more than one new address, cannot cutthrough */
2027 if (addr_new && addr_new->next)
2028 cancel_cutthrough_connection("multiple addresses from routing");
2034 } /* Loop for generated addresses */
2036 /* Display the full results of the successful routing, including any generated
2037 addresses. Control gets here only when full_info is set, which requires f not
2038 to be NULL, and this occurs only when a top-level verify is called with the
2039 debugging switch on.
2041 If there are no local and no remote addresses, and there were no pipes, files,
2042 or autoreplies, and there were no errors or deferments, the message is to be
2043 discarded, usually because of the use of :blackhole: in an alias file. */
2045 if (allok && !addr_local && !addr_remote)
2047 fprintf(f, "mail to %s is discarded\n", address);
2051 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2054 address_item *addr = addr_list;
2055 address_item *p = addr->parent;
2056 transport_instance * tp = addr->transport;
2058 addr_list = addr->next;
2060 fprintf(f, "%s", CS addr->address);
2061 #ifdef EXPERIMENTAL_SRS
2062 if(addr->prop.srs_sender)
2063 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2066 /* If the address is a duplicate, show something about it. */
2068 if (!testflag(addr, af_pfr))
2071 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2072 fprintf(f, " [duplicate, would not be delivered]");
2073 else tree_add_duplicate(addr->unique, addr);
2076 /* Now show its parents */
2078 for (p = addr->parent; p; p = p->parent)
2079 fprintf(f, "\n <-- %s", p->address);
2082 /* Show router, and transport */
2084 fprintf(f, "router = %s, transport = %s\n",
2085 addr->router->name, tp ? tp->name : US"unset");
2087 /* Show any hosts that are set up by a router unless the transport
2088 is going to override them; fiddle a bit to get a nice format. */
2090 if (addr->host_list && tp && !tp->overrides_hosts)
2095 for (h = addr->host_list; h; h = h->next)
2096 { /* get max lengths of host names, addrs */
2097 int len = Ustrlen(h->name);
2098 if (len > maxlen) maxlen = len;
2099 len = h->address ? Ustrlen(h->address) : 7;
2100 if (len > maxaddlen) maxaddlen = len;
2102 for (h = addr->host_list; h; h = h->next)
2104 fprintf(f, " host %-*s ", maxlen, h->name);
2107 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2108 else if (tp->info->local)
2109 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2111 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2113 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2114 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2115 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2116 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2122 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2123 the -bv or -bt case). */
2127 tls_modify_variables(&tls_in);
2135 /*************************************************
2136 * Check headers for syntax errors *
2137 *************************************************/
2139 /* This function checks those header lines that contain addresses, and verifies
2140 that all the addresses therein are syntactially correct.
2143 msgptr where to put an error message
2150 verify_check_headers(uschar **msgptr)
2156 for (h = header_list; h != NULL && yield == OK; h = h->next)
2158 if (h->type != htype_from &&
2159 h->type != htype_reply_to &&
2160 h->type != htype_sender &&
2161 h->type != htype_to &&
2162 h->type != htype_cc &&
2163 h->type != htype_bcc)
2166 colon = Ustrchr(h->text, ':');
2168 while (isspace(*s)) s++;
2170 /* Loop for multiple addresses in the header, enabling group syntax. Note
2171 that we have to reset this after the header has been scanned. */
2173 parse_allow_group = TRUE;
2177 uschar *ss = parse_find_address_end(s, FALSE);
2178 uschar *recipient, *errmess;
2179 int terminator = *ss;
2180 int start, end, domain;
2182 /* Temporarily terminate the string at this point, and extract the
2183 operative address within, allowing group syntax. */
2186 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2189 /* Permit an unqualified address only if the message is local, or if the
2190 sending host is configured to be permitted to send them. */
2192 if (recipient != NULL && domain == 0)
2194 if (h->type == htype_from || h->type == htype_sender)
2196 if (!allow_unqualified_sender) recipient = NULL;
2200 if (!allow_unqualified_recipient) recipient = NULL;
2202 if (recipient == NULL) errmess = US"unqualified address not permitted";
2205 /* It's an error if no address could be extracted, except for the special
2206 case of an empty address. */
2208 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2210 uschar *verb = US"is";
2215 /* Arrange not to include any white space at the end in the
2216 error message or the header name. */
2218 while (t > s && isspace(t[-1])) t--;
2219 while (tt > h->text && isspace(tt[-1])) tt--;
2221 /* Add the address that failed to the error message, since in a
2222 header with very many addresses it is sometimes hard to spot
2223 which one is at fault. However, limit the amount of address to
2224 quote - cases have been seen where, for example, a missing double
2225 quote in a humungous To: header creates an "address" that is longer
2226 than string_sprintf can handle. */
2235 /* deconst cast ok as we're passing a non-const to string_printing() */
2236 *msgptr = US string_printing(
2237 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2238 errmess, tt - h->text, h->text, verb, len, s));
2241 break; /* Out of address loop */
2244 /* Advance to the next address */
2246 s = ss + (terminator? 1:0);
2247 while (isspace(*s)) s++;
2248 } /* Next address */
2250 parse_allow_group = FALSE;
2251 parse_found_group = FALSE;
2252 } /* Next header unless yield has been set FALSE */
2258 /*************************************************
2259 * Check header names for 8-bit characters *
2260 *************************************************/
2262 /* This function checks for invalid characters in header names. See
2263 RFC 5322, 2.2. and RFC 6532, 3.
2266 msgptr where to put an error message
2273 verify_check_header_names_ascii(uschar **msgptr)
2278 for (h = header_list; h != NULL; h = h->next)
2280 colon = Ustrchr(h->text, ':');
2281 for(s = h->text; s < colon; s++)
2283 if ((*s < 33) || (*s > 126))
2285 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2286 colon - h->text, h->text);
2294 /*************************************************
2295 * Check for blind recipients *
2296 *************************************************/
2298 /* This function checks that every (envelope) recipient is mentioned in either
2299 the To: or Cc: header lines, thus detecting blind carbon copies.
2301 There are two ways of scanning that could be used: either scan the header lines
2302 and tick off the recipients, or scan the recipients and check the header lines.
2303 The original proposed patch did the former, but I have chosen to do the latter,
2304 because (a) it requires no memory and (b) will use fewer resources when there
2305 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2308 Returns: OK if there are no blind recipients
2309 FAIL if there is at least one blind recipient
2313 verify_check_notblind(void)
2316 for (i = 0; i < recipients_count; i++)
2320 uschar *address = recipients_list[i].address;
2322 for (h = header_list; !found && h != NULL; h = h->next)
2326 if (h->type != htype_to && h->type != htype_cc) continue;
2328 colon = Ustrchr(h->text, ':');
2330 while (isspace(*s)) s++;
2332 /* Loop for multiple addresses in the header, enabling group syntax. Note
2333 that we have to reset this after the header has been scanned. */
2335 parse_allow_group = TRUE;
2339 uschar *ss = parse_find_address_end(s, FALSE);
2340 uschar *recipient,*errmess;
2341 int terminator = *ss;
2342 int start, end, domain;
2344 /* Temporarily terminate the string at this point, and extract the
2345 operative address within, allowing group syntax. */
2348 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2351 /* If we found a valid recipient that has a domain, compare it with the
2352 envelope recipient. Local parts are compared case-sensitively, domains
2353 case-insensitively. By comparing from the start with length "domain", we
2354 include the "@" at the end, which ensures that we are comparing the whole
2355 local part of each address. */
2357 if (recipient != NULL && domain != 0)
2359 found = Ustrncmp(recipient, address, domain) == 0 &&
2360 strcmpic(recipient + domain, address + domain) == 0;
2364 /* Advance to the next address */
2366 s = ss + (terminator? 1:0);
2367 while (isspace(*s)) s++;
2368 } /* Next address */
2370 parse_allow_group = FALSE;
2371 parse_found_group = FALSE;
2372 } /* Next header (if found is false) */
2374 if (!found) return FAIL;
2375 } /* Next recipient */
2382 /*************************************************
2383 * Find if verified sender *
2384 *************************************************/
2386 /* Usually, just a single address is verified as the sender of the message.
2387 However, Exim can be made to verify other addresses as well (often related in
2388 some way), and this is useful in some environments. There may therefore be a
2389 chain of such addresses that have previously been tested. This function finds
2390 whether a given address is on the chain.
2392 Arguments: the address to be verified
2393 Returns: pointer to an address item, or NULL
2397 verify_checked_sender(uschar *sender)
2400 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2401 if (Ustrcmp(sender, addr->address) == 0) break;
2409 /*************************************************
2410 * Get valid header address *
2411 *************************************************/
2413 /* Scan the originator headers of the message, looking for an address that
2414 verifies successfully. RFC 822 says:
2416 o The "Sender" field mailbox should be sent notices of
2417 any problems in transport or delivery of the original
2418 messages. If there is no "Sender" field, then the
2419 "From" field mailbox should be used.
2421 o If the "Reply-To" field exists, then the reply should
2422 go to the addresses indicated in that field and not to
2423 the address(es) indicated in the "From" field.
2425 So we check a Sender field if there is one, else a Reply_to field, else a From
2426 field. As some strange messages may have more than one of these fields,
2427 especially if they are resent- fields, check all of them if there is more than
2431 user_msgptr points to where to put a user error message
2432 log_msgptr points to where to put a log error message
2433 callout timeout for callout check (passed to verify_address())
2434 callout_overall overall callout timeout (ditto)
2435 callout_connect connect callout timeout (ditto)
2436 se_mailfrom mailfrom for verify; NULL => ""
2437 pm_mailfrom sender for pm callout check (passed to verify_address())
2438 options callout options (passed to verify_address())
2439 verrno where to put the address basic_errno
2441 If log_msgptr is set to something without setting user_msgptr, the caller
2442 normally uses log_msgptr for both things.
2444 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2445 FAIL is given if no appropriate headers are found
2449 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2450 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2451 uschar *pm_mailfrom, int options, int *verrno)
2453 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2458 for (i = 0; i < 3 && !done; i++)
2461 for (h = header_list; h != NULL && !done; h = h->next)
2463 int terminator, new_ok;
2464 uschar *s, *ss, *endname;
2466 if (h->type != header_types[i]) continue;
2467 s = endname = Ustrchr(h->text, ':') + 1;
2469 /* Scan the addresses in the header, enabling group syntax. Note that we
2470 have to reset this after the header has been scanned. */
2472 parse_allow_group = TRUE;
2476 address_item *vaddr;
2478 while (isspace(*s) || *s == ',') s++;
2479 if (*s == 0) break; /* End of header */
2481 ss = parse_find_address_end(s, FALSE);
2483 /* The terminator is a comma or end of header, but there may be white
2484 space preceding it (including newline for the last address). Move back
2485 past any white space so we can check against any cached envelope sender
2486 address verifications. */
2488 while (isspace(ss[-1])) ss--;
2492 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2493 (int)(endname - h->text), h->text, s);
2495 /* See if we have already verified this address as an envelope sender,
2496 and if so, use the previous answer. */
2498 vaddr = verify_checked_sender(s);
2500 if (vaddr != NULL && /* Previously checked */
2501 (callout <= 0 || /* No callout needed; OR */
2502 vaddr->special_action > 256)) /* Callout was done */
2504 new_ok = vaddr->special_action & 255;
2505 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2506 *ss = terminator; /* Restore shortened string */
2509 /* Otherwise we run the verification now. We must restore the shortened
2510 string before running the verification, so the headers are correct, in
2511 case there is any rewriting. */
2515 int start, end, domain;
2516 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2521 /* If we found an empty address, just carry on with the next one, but
2522 kill the message. */
2524 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2531 /* If verification failed because of a syntax error, fail this
2532 function, and ensure that the failing address gets added to the error
2535 if (address == NULL)
2538 while (ss > s && isspace(ss[-1])) ss--;
2539 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2540 "scanning for sender: %s in \"%.*s\"",
2541 endname - h->text, h->text, *log_msgptr, ss - s, s);
2547 /* Else go ahead with the sender verification. But it isn't *the*
2548 sender of the message, so set vopt_fake_sender to stop sender_address
2549 being replaced after rewriting or qualification. */
2553 vaddr = deliver_make_addr(address, FALSE);
2554 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2555 callout, callout_overall, callout_connect, se_mailfrom,
2560 /* We now have the result, either newly found, or cached. If we are
2561 giving out error details, set a specific user error. This means that the
2562 last of these will be returned to the user if all three fail. We do not
2563 set a log message - the generic one below will be used. */
2567 *verrno = vaddr->basic_errno;
2568 if (smtp_return_error_details)
2570 *user_msgptr = string_sprintf("Rejected after DATA: "
2571 "could not verify \"%.*s\" header address\n%s: %s",
2572 endname - h->text, h->text, vaddr->address, vaddr->message);
2576 /* Success or defer */
2585 if (new_ok == DEFER) yield = DEFER;
2587 /* Move on to any more addresses in the header */
2590 } /* Next address */
2592 parse_allow_group = FALSE;
2593 parse_found_group = FALSE;
2594 } /* Next header, unless done */
2595 } /* Next header type unless done */
2597 if (yield == FAIL && *log_msgptr == NULL)
2598 *log_msgptr = US"there is no valid sender in any header line";
2600 if (yield == DEFER && *log_msgptr == NULL)
2601 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2609 /*************************************************
2610 * Get RFC 1413 identification *
2611 *************************************************/
2613 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2614 the timeout is set to zero, then the query is not done. There may also be lists
2615 of hosts and nets which are exempt. To guard against malefactors sending
2616 non-printing characters which could, for example, disrupt a message's headers,
2617 make sure the string consists of printing characters only.
2620 port the port to connect to; usually this is IDENT_PORT (113), but when
2621 running in the test harness with -bh a different value is used.
2625 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2629 verify_get_ident(int port)
2631 int sock, host_af, qlen;
2632 int received_sender_port, received_interface_port, n;
2634 uschar buffer[2048];
2636 /* Default is no ident. Check whether we want to do an ident check for this
2639 sender_ident = NULL;
2640 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2643 DEBUG(D_ident) debug_printf("doing ident callback\n");
2645 /* Set up a connection to the ident port of the remote host. Bind the local end
2646 to the incoming interface address. If the sender host address is an IPv6
2647 address, the incoming interface address will also be IPv6. */
2649 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2650 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2652 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2654 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2659 if (ip_connect(sock, host_af, sender_host_address, port,
2660 rfc1413_query_timeout, TRUE) < 0)
2662 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2663 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2664 sender_host_address);
2666 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2667 sender_host_address, strerror(errno));
2671 /* Construct and send the query. */
2673 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2674 qlen = Ustrlen(buffer);
2675 if (send(sock, buffer, qlen, 0) < 0)
2677 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2681 /* Read a response line. We put it into the rest of the buffer, using several
2682 recv() calls if necessary. */
2690 int size = sizeof(buffer) - (p - buffer);
2692 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2693 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2694 if (count <= 0) goto END_OFF; /* Read error or EOF */
2696 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2697 generous, and accept a plain \n terminator as well. The only illegal
2700 for (pp = p; pp < p + count; pp++)
2702 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2705 if (pp[-1] == '\r') pp--;
2707 goto GOT_DATA; /* Break out of both loops */
2711 /* Reached the end of the data without finding \n. Let the loop continue to
2712 read some more, if there is room. */
2719 /* We have received a line of data. Check it carefully. It must start with the
2720 same two port numbers that we sent, followed by data as defined by the RFC. For
2723 12345 , 25 : USERID : UNIX :root
2725 However, the amount of white space may be different to what we sent. In the
2726 "osname" field there may be several sub-fields, comma separated. The data we
2727 actually want to save follows the third colon. Some systems put leading spaces
2728 in it - we discard those. */
2730 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2731 &received_interface_port, &n) != 2 ||
2732 received_sender_port != sender_host_port ||
2733 received_interface_port != interface_port)
2736 p = buffer + qlen + n;
2737 while(isspace(*p)) p++;
2738 if (*p++ != ':') goto END_OFF;
2739 while(isspace(*p)) p++;
2740 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2742 while(isspace(*p)) p++;
2743 if (*p++ != ':') goto END_OFF;
2744 while (*p != 0 && *p != ':') p++;
2745 if (*p++ == 0) goto END_OFF;
2746 while(isspace(*p)) p++;
2747 if (*p == 0) goto END_OFF;
2749 /* The rest of the line is the data we want. We turn it into printing
2750 characters when we save it, so that it cannot mess up the format of any logging
2751 or Received: lines into which it gets inserted. We keep a maximum of 127
2752 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2754 sender_ident = US string_printing(string_copyn(p, 127));
2755 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2765 /*************************************************
2766 * Match host to a single host-list item *
2767 *************************************************/
2769 /* This function compares a host (name or address) against a single item
2770 from a host list. The host name gets looked up if it is needed and is not
2771 already known. The function is called from verify_check_this_host() via
2772 match_check_list(), which is why most of its arguments are in a single block.
2775 arg the argument block (see below)
2776 ss the host-list item
2777 valueptr where to pass back looked up data, or NULL
2778 error for error message when returning ERROR
2781 host_name (a) the host name, or
2782 (b) NULL, implying use sender_host_name and
2783 sender_host_aliases, looking them up if required, or
2784 (c) the empty string, meaning that only IP address matches
2786 host_address the host address
2787 host_ipv4 the IPv4 address taken from an IPv6 one
2791 DEFER lookup deferred
2792 ERROR (a) failed to find the host name or IP address, or
2793 (b) unknown lookup type specified, or
2794 (c) host name encountered when only IP addresses are
2799 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2801 check_host_block *cb = (check_host_block *)arg;
2804 BOOL iplookup = FALSE;
2805 BOOL isquery = FALSE;
2806 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2811 /* Optimize for the special case when the pattern is "*". */
2813 if (*ss == '*' && ss[1] == 0) return OK;
2815 /* If the pattern is empty, it matches only in the case when there is no host -
2816 this can occur in ACL checking for SMTP input using the -bs option. In this
2817 situation, the host address is the empty string. */
2819 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2820 if (*ss == 0) return FAIL;
2822 /* If the pattern is precisely "@" then match against the primary host name,
2823 provided that host name matching is permitted; if it's "@[]" match against the
2824 local host's IP addresses. */
2830 if (isiponly) return ERROR;
2831 ss = primary_hostname;
2833 else if (Ustrcmp(ss, "@[]") == 0)
2835 ip_address_item *ip;
2836 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2837 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2842 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2843 a (possibly masked) comparison with the current IP address. */
2845 if (string_is_ip_address(ss, &maskoffset) != 0)
2846 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2848 /* The pattern is not an IP address. A common error that people make is to omit
2849 one component of an IPv4 address, either by accident, or believing that, for
2850 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,
2851 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2852 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2853 ancient specification.) To aid in debugging these cases, we give a specific
2854 error if the pattern contains only digits and dots or contains a slash preceded
2855 only by digits and dots (a slash at the start indicates a file name and of
2856 course slashes may be present in lookups, but not preceded only by digits and
2859 for (t = ss; isdigit(*t) || *t == '.'; t++);
2860 if (*t == 0 || (*t == '/' && t != ss))
2862 *error = US"malformed IPv4 address or address mask";
2866 /* See if there is a semicolon in the pattern */
2868 semicolon = Ustrchr(ss, ';');
2870 /* If we are doing an IP address only match, then all lookups must be IP
2871 address lookups, even if there is no "net-". */
2875 iplookup = semicolon != NULL;
2878 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2879 a lookup on a masked IP network, in textual form. We obey this code even if we
2880 have already set iplookup, so as to skip over the "net-" prefix and to set the
2881 mask length. The net- stuff really only applies to single-key lookups where the
2882 key is implicit. For query-style lookups the key is specified in the query.
2883 From release 4.30, the use of net- for query style is no longer needed, but we
2884 retain it for backward compatibility. */
2886 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2889 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2890 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2891 iplookup = (*t++ == '-');
2895 /* Do the IP address lookup if that is indeed what we have */
2903 uschar *filename, *key, *result;
2906 /* Find the search type */
2908 search_type = search_findtype(t, semicolon - t);
2910 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2911 search_error_message);
2913 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2914 is no file name, and the "key" is just the query. For query-style with a file
2915 name, we have to fish the file off the start of the query. For a single-key
2916 lookup, the key is the current IP address, masked appropriately, and
2917 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2918 dot separators instead of colons, except when the lookup type is "iplsearch".
2921 if (mac_islookup(search_type, lookup_absfilequery))
2923 filename = semicolon + 1;
2925 while (*key != 0 && !isspace(*key)) key++;
2926 filename = string_copyn(filename, key - filename);
2927 while (isspace(*key)) key++;
2929 else if (mac_islookup(search_type, lookup_querystyle))
2932 key = semicolon + 1;
2934 else /* Single-key style */
2936 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2938 insize = host_aton(cb->host_address, incoming);
2939 host_mask(insize, incoming, mlen);
2940 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2942 filename = semicolon + 1;
2945 /* Now do the actual lookup; note that there is no search_close() because
2946 of the caching arrangements. */
2948 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2949 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2951 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2952 if (valueptr != NULL) *valueptr = result;
2953 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2956 /* The pattern is not an IP address or network reference of any kind. That is,
2957 it is a host name pattern. If this is an IP only match, there's an error in the
2962 *error = US"cannot match host name in match_ip list";
2966 /* Check the characters of the pattern to see if they comprise only letters,
2967 digits, full stops, and hyphens (the constituents of domain names). Allow
2968 underscores, as they are all too commonly found. Sigh. Also, if
2969 allow_utf8_domains is set, allow top-bit characters. */
2971 for (t = ss; *t != 0; t++)
2972 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2973 (!allow_utf8_domains || *t < 128)) break;
2975 /* If the pattern is a complete domain name, with no fancy characters, look up
2976 its IP address and match against that. Note that a multi-homed host will add
2977 items to the chain. */
2988 /* Using byname rather than bydns here means we cannot determine dnssec
2989 status. On the other hand it is unclear how that could be either
2990 propagated up or enforced. */
2992 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2993 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2996 for (hh = &h; hh != NULL; hh = hh->next)
2998 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3002 if (rc == HOST_FIND_AGAIN) return DEFER;
3003 *error = string_sprintf("failed to find IP address for %s", ss);
3007 /* Almost all subsequent comparisons require the host name, and can be done
3008 using the general string matching function. When this function is called for
3009 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3010 must use sender_host_name and its aliases, looking them up if necessary. */
3012 if (cb->host_name != NULL) /* Explicit host name given */
3013 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3016 /* Host name not given; in principle we need the sender host name and its
3017 aliases. However, for query-style lookups, we do not need the name if the
3018 query does not contain $sender_host_name. From release 4.23, a reference to
3019 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3022 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3024 const uschar *affix;
3025 int partial, affixlen, starflags, id;
3028 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3031 if (id < 0) /* Unknown lookup type */
3033 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3034 search_error_message, ss);
3037 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3042 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3045 case DEFER: return DEFER;
3046 default: return FAIL;
3050 /* Not a query-style lookup; must ensure the host name is present, and then we
3051 do a check on the name and all its aliases. */
3053 if (sender_host_name == NULL)
3055 HDEBUG(D_host_lookup)
3056 debug_printf("sender host name required, to match against %s\n", ss);
3057 if (host_lookup_failed || host_name_lookup() != OK)
3059 *error = string_sprintf("failed to find host name for %s",
3060 sender_host_address);;
3063 host_build_sender_fullhost();
3066 /* Match on the sender host name, using the general matching function */
3068 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3072 case DEFER: return DEFER;
3075 /* If there are aliases, try matching on them. */
3077 aliases = sender_host_aliases;
3078 while (*aliases != NULL)
3080 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3083 case DEFER: return DEFER;
3092 /*************************************************
3093 * Check a specific host matches a host list *
3094 *************************************************/
3096 /* This function is passed a host list containing items in a number of
3097 different formats and the identity of a host. Its job is to determine whether
3098 the given host is in the set of hosts defined by the list. The host name is
3099 passed as a pointer so that it can be looked up if needed and not already
3100 known. This is commonly the case when called from verify_check_host() to check
3101 an incoming connection. When called from elsewhere the host name should usually
3104 This function is now just a front end to match_check_list(), which runs common
3105 code for scanning a list. We pass it the check_host() function to perform a
3109 listptr pointer to the host list
3110 cache_bits pointer to cache for named lists, or NULL
3111 host_name the host name or NULL, implying use sender_host_name and
3112 sender_host_aliases, looking them up if required
3113 host_address the IP address
3114 valueptr if not NULL, data from a lookup is passed back here
3116 Returns: OK if the host is in the defined set
3117 FAIL if the host is not in the defined set,
3118 DEFER if a data lookup deferred (not a host lookup)
3120 If the host name was needed in order to make a comparison, and could not be
3121 determined from the IP address, the result is FAIL unless the item
3122 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3125 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3126 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3129 unsigned int *local_cache_bits = cache_bits;
3130 const uschar *save_host_address = deliver_host_address;
3131 check_host_block cb;
3132 cb.host_name = host_name;
3133 cb.host_address = host_address;
3135 if (valueptr != NULL) *valueptr = NULL;
3137 /* If the host address starts off ::ffff: it is an IPv6 address in
3138 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3141 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3142 host_address + 7 : host_address;
3144 /* During the running of the check, put the IP address into $host_address. In
3145 the case of calls from the smtp transport, it will already be there. However,
3146 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3147 the safe side, any existing setting is preserved, though as I write this
3148 (November 2004) I can't see any cases where it is actually needed. */
3150 deliver_host_address = host_address;
3151 rc = match_check_list(
3152 listptr, /* the list */
3153 0, /* separator character */
3154 &hostlist_anchor, /* anchor pointer */
3155 &local_cache_bits, /* cache pointer */
3156 check_host, /* function for testing */
3157 &cb, /* argument for function */
3158 MCL_HOST, /* type of check */
3159 (host_address == sender_host_address)?
3160 US"host" : host_address, /* text for debugging */
3161 valueptr); /* where to pass back data */
3162 deliver_host_address = save_host_address;
3169 /*************************************************
3170 * Check the given host item matches a list *
3171 *************************************************/
3173 verify_check_given_host(uschar **listptr, host_item *host)
3175 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3178 /*************************************************
3179 * Check the remote host matches a list *
3180 *************************************************/
3182 /* This is a front end to verify_check_this_host(), created because checking
3183 the remote host is a common occurrence. With luck, a good compiler will spot
3184 the tail recursion and optimize it. If there's no host address, this is
3185 command-line SMTP input - check against an empty string for the address.
3188 listptr pointer to the host list
3190 Returns: the yield of verify_check_this_host(),
3191 i.e. OK, FAIL, or DEFER
3195 verify_check_host(uschar **listptr)
3197 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3198 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3205 /*************************************************
3206 * Invert an IP address *
3207 *************************************************/
3209 /* Originally just used for DNS xBL lists, now also used for the
3210 reverse_ip expansion operator.
3213 buffer where to put the answer
3214 address the address to invert
3218 invert_address(uschar *buffer, uschar *address)
3221 uschar *bptr = buffer;
3223 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3224 to the IPv4 part only. */
3226 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3228 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3231 if (host_aton(address, bin) == 1)
3235 for (i = 0; i < 4; i++)
3237 sprintf(CS bptr, "%d.", x & 255);
3238 while (*bptr) bptr++;
3243 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3244 in any DNS black lists, and the format in which they will be looked up is
3245 unknown. This is just a guess. */
3251 for (j = 3; j >= 0; j--)
3254 for (i = 0; i < 8; i++)
3256 sprintf(CS bptr, "%x.", x & 15);
3257 while (*bptr) bptr++;
3264 /* Remove trailing period -- this is needed so that both arbitrary
3265 dnsbl keydomains and inverted addresses may be combined with the
3266 same format string, "%s.%s" */
3273 /*************************************************
3274 * Perform a single dnsbl lookup *
3275 *************************************************/
3277 /* This function is called from verify_check_dnsbl() below. It is also called
3278 recursively from within itself when domain and domain_txt are different
3279 pointers, in order to get the TXT record from the alternate domain.
3282 domain the outer dnsbl domain
3283 domain_txt alternate domain to lookup TXT record on success; when the
3284 same domain is to be used, domain_txt == domain (that is,
3285 the pointers must be identical, not just the text)
3286 keydomain the current keydomain (for debug message)
3287 prepend subdomain to lookup (like keydomain, but
3288 reversed if IP address)
3289 iplist the list of matching IP addresses, or NULL for "any"
3290 bitmask true if bitmask matching is wanted
3291 match_type condition for 'succeed' result
3292 0 => Any RR in iplist (=)
3293 1 => No RR in iplist (!=)
3294 2 => All RRs in iplist (==)
3295 3 => Some RRs not in iplist (!==)
3296 the two bits are defined as MT_NOT and MT_ALL
3297 defer_return what to return for a defer
3299 Returns: OK if lookup succeeded
3304 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3305 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3311 dnsbl_cache_block *cb;
3312 int old_pool = store_pool;
3313 uschar query[256]; /* DNS domain max length */
3315 /* Construct the specific query domainname */
3317 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3319 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3320 "(ignored): %s...", query);
3324 /* Look for this query in the cache. */
3326 if ( (t = tree_search(dnsbl_cache, query))
3327 && (cb = t->data.ptr)->expiry > time(NULL)
3330 /* Previous lookup was cached */
3333 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3336 /* If not cached from a previous lookup, we must do a DNS lookup, and
3337 cache the result in permanent memory. */
3343 store_pool = POOL_PERM;
3347 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3351 { /* Set up a tree entry to cache the lookup */
3352 t = store_get(sizeof(tree_node) + Ustrlen(query));
3353 Ustrcpy(t->name, query);
3354 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3355 (void)tree_insertnode(&dnsbl_cache, t);
3358 /* Do the DNS lookup . */
3360 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3361 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3362 cb->text_set = FALSE;
3366 /* If the lookup succeeded, cache the RHS address. The code allows for
3367 more than one address - this was for complete generality and the possible
3368 use of A6 records. However, A6 records have been reduced to experimental
3369 status (August 2001) and may die out. So they may never get used at all,
3370 let alone in dnsbl records. However, leave the code here, just in case.
3372 Quite apart from one A6 RR generating multiple addresses, there are DNS
3373 lists that return more than one A record, so we must handle multiple
3374 addresses generated in that way as well.
3376 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3377 or some suitably far-future time if none were found. */
3379 if (cb->rc == DNS_SUCCEED)
3382 dns_address **addrp = &(cb->rhs);
3383 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3385 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3387 if (rr->type == T_A)
3389 dns_address *da = dns_address_from_rr(&dnsa, rr);
3393 while (da->next != NULL) da = da->next;
3394 addrp = &(da->next);
3395 if (ttl > rr->ttl) ttl = rr->ttl;
3400 /* If we didn't find any A records, change the return code. This can
3401 happen when there is a CNAME record but there are no A records for what
3404 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3407 cb->expiry = time(NULL)+ttl;
3408 store_pool = old_pool;
3411 /* We now have the result of the DNS lookup, either newly done, or cached
3412 from a previous call. If the lookup succeeded, check against the address
3413 list if there is one. This may be a positive equality list (introduced by
3414 "="), a negative equality list (introduced by "!="), a positive bitmask
3415 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3417 if (cb->rc == DNS_SUCCEED)
3419 dns_address *da = NULL;
3420 uschar *addlist = cb->rhs->address;
3422 /* For A and AAAA records, there may be multiple addresses from multiple
3423 records. For A6 records (currently not expected to be used) there may be
3424 multiple addresses from a single record. */
3426 for (da = cb->rhs->next; da != NULL; da = da->next)
3427 addlist = string_sprintf("%s, %s", addlist, da->address);
3429 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3432 /* Address list check; this can be either for equality, or via a bitmask.
3433 In the latter case, all the bits must match. */
3437 for (da = cb->rhs; da != NULL; da = da->next)
3441 const uschar *ptr = iplist;
3444 /* Handle exact matching */
3448 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3450 if (Ustrcmp(CS da->address, ip) == 0) break;
3454 /* Handle bitmask matching */
3461 /* At present, all known DNS blocking lists use A records, with
3462 IPv4 addresses on the RHS encoding the information they return. I
3463 wonder if this will linger on as the last vestige of IPv4 when IPv6
3464 is ubiquitous? Anyway, for now we use paranoia code to completely
3465 ignore IPv6 addresses. The default mask is 0, which always matches.
3466 We change this only for IPv4 addresses in the list. */
3468 if (host_aton(da->address, address) == 1) mask = address[0];
3470 /* Scan the returned addresses, skipping any that are IPv6 */
3472 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3474 if (host_aton(ip, address) != 1) continue;
3475 if ((address[0] & mask) == address[0]) break;
3481 (a) An IP address in an any ('=') list matched, or
3482 (b) No IP address in an all ('==') list matched
3484 then we're done searching. */
3486 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3489 /* If da == NULL, either
3491 (a) No IP address in an any ('=') list matched, or
3492 (b) An IP address in an all ('==') list didn't match
3494 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3497 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3505 res = US"was no match";
3508 res = US"was an exclude match";
3511 res = US"was an IP address that did not match";
3514 res = US"were no IP addresses that did not match";
3517 debug_printf("=> but we are not accepting this block class because\n");
3518 debug_printf("=> there %s for %s%c%s\n",
3520 ((match_type & MT_ALL) == 0)? "" : "=",
3521 bitmask? '&' : '=', iplist);
3527 /* Either there was no IP list, or the record matched, implying that the
3528 domain is on the list. We now want to find a corresponding TXT record. If an
3529 alternate domain is specified for the TXT record, call this function
3530 recursively to look that up; this has the side effect of re-checking that
3531 there is indeed an A record at the alternate domain. */
3533 if (domain_txt != domain)
3534 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3535 FALSE, match_type, defer_return);
3537 /* If there is no alternate domain, look up a TXT record in the main domain
3538 if it has not previously been cached. */
3542 cb->text_set = TRUE;
3543 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3546 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3548 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3549 if (rr->type == T_TXT) break;
3552 int len = (rr->data)[0];
3553 if (len > 511) len = 127;
3554 store_pool = POOL_PERM;
3555 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3556 store_pool = old_pool;
3561 dnslist_value = addlist;
3562 dnslist_text = cb->text;
3566 /* There was a problem with the DNS lookup */
3568 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3570 log_write(L_dnslist_defer, LOG_MAIN,
3571 "DNS list lookup defer (probably timeout) for %s: %s", query,
3572 (defer_return == OK)? US"assumed in list" :
3573 (defer_return == FAIL)? US"assumed not in list" :
3574 US"returned DEFER");
3575 return defer_return;
3578 /* No entry was found in the DNS; continue for next domain */
3582 debug_printf("DNS lookup for %s failed\n", query);
3583 debug_printf("=> that means %s is not listed at %s\n",
3593 /*************************************************
3594 * Check host against DNS black lists *
3595 *************************************************/
3597 /* This function runs checks against a list of DNS black lists, until one
3598 matches. Each item on the list can be of the form
3600 domain=ip-address/key
3602 The domain is the right-most domain that is used for the query, for example,
3603 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3604 if the DNS lookup returns a matching IP address. Several addresses may be
3605 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3607 If no key is given, what is looked up in the domain is the inverted IP address
3608 of the current client host. If a key is given, it is used to construct the
3609 domain for the lookup. For example:
3611 dsn.rfc-ignorant.org/$sender_address_domain
3613 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3614 then we check for a TXT record for an error message, and if found, save its
3615 value in $dnslist_text. We also cache everything in a tree, to optimize
3618 The TXT record is normally looked up in the same domain as the A record, but
3619 when many lists are combined in a single DNS domain, this will not be a very
3620 specific message. It is possible to specify a different domain for looking up
3621 TXT records; this is given before the main domain, comma-separated. For
3624 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3625 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3627 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3629 Note: an address for testing RBL is 192.203.178.39
3630 Note: an address for testing DUL is 192.203.178.4
3631 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3635 listptr the domain/address/data list
3636 log_msgptr log message on error
3638 Returns: OK successful lookup (i.e. the address is on the list), or
3639 lookup deferred after +include_unknown
3640 FAIL name not found, or no data found for the given type, or
3641 lookup deferred after +exclude_unknown (default)
3642 DEFER lookup failure, if +defer_unknown was set
3646 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3649 int defer_return = FAIL;
3650 const uschar *list = *listptr;
3653 uschar buffer[1024];
3654 uschar revadd[128]; /* Long enough for IPv6 address */
3656 /* Indicate that the inverted IP address is not yet set up */
3660 /* In case this is the first time the DNS resolver is being used. */
3662 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3664 /* Loop through all the domains supplied, until something matches */
3666 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3669 BOOL bitmask = FALSE;
3676 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3678 /* Deal with special values that change the behaviour on defer */
3680 if (domain[0] == '+')
3682 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3683 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3684 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3686 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3691 /* See if there's explicit data to be looked up */
3693 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3695 /* See if there's a list of addresses supplied after the domain name. This is
3696 introduced by an = or a & character; if preceded by = we require all matches
3697 and if preceded by ! we invert the result. */
3699 if (!(iplist = Ustrchr(domain, '=')))
3702 iplist = Ustrchr(domain, '&');
3705 if (iplist) /* Found either = or & */
3707 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3709 match_type |= MT_NOT;
3713 *iplist++ = 0; /* Terminate domain, move on */
3715 /* If we found = (bitmask == FALSE), check for == or =& */
3717 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3719 bitmask = *iplist++ == '&';
3720 match_type |= MT_ALL;
3725 /* If there is a comma in the domain, it indicates that a second domain for
3726 looking up TXT records is provided, before the main domain. Otherwise we must
3727 set domain_txt == domain. */
3729 domain_txt = domain;
3730 comma = Ustrchr(domain, ',');
3737 /* Check that what we have left is a sensible domain name. There is no reason
3738 why these domains should in fact use the same syntax as hosts and email
3739 domains, but in practice they seem to. However, there is little point in
3740 actually causing an error here, because that would no doubt hold up incoming
3741 mail. Instead, I'll just log it. */
3743 for (s = domain; *s != 0; s++)
3745 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3747 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3748 "strange characters - is this right?", domain);
3753 /* Check the alternate domain if present */
3755 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3757 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3759 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3760 "strange characters - is this right?", domain_txt);
3765 /* If there is no key string, construct the query by adding the domain name
3766 onto the inverted host address, and perform a single DNS lookup. */
3770 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3772 *log_msgptr = string_sprintf
3773 ("cannot test auto-keyed dnslists condition in %s ACL",
3774 acl_wherenames[where]);
3777 if (sender_host_address == NULL) return FAIL; /* can never match */
3778 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3779 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3780 iplist, bitmask, match_type, defer_return);
3783 dnslist_domain = string_copy(domain_txt);
3784 dnslist_matched = string_copy(sender_host_address);
3785 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3786 sender_host_address, dnslist_domain);
3788 if (rc != FAIL) return rc; /* OK or DEFER */
3791 /* If there is a key string, it can be a list of domains or IP addresses to
3792 be concatenated with the main domain. */
3799 uschar keybuffer[256];
3800 uschar keyrevadd[128];
3802 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3803 sizeof(keybuffer))) != NULL)
3805 uschar *prepend = keydomain;
3807 if (string_is_ip_address(keydomain, NULL) != 0)
3809 invert_address(keyrevadd, keydomain);
3810 prepend = keyrevadd;
3813 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3814 bitmask, match_type, defer_return);
3818 dnslist_domain = string_copy(domain_txt);
3819 dnslist_matched = string_copy(keydomain);
3820 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3821 keydomain, dnslist_domain);
3825 /* If the lookup deferred, remember this fact. We keep trying the rest
3826 of the list to see if we get a useful result, and if we don't, we return
3827 DEFER at the end. */
3829 if (rc == DEFER) defer = TRUE;
3830 } /* continue with next keystring domain/address */
3832 if (defer) return DEFER;
3834 } /* continue with next dnsdb outer domain */
3841 /* End of verify.c */