1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
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\" was: %s",
444 big_buffer, string_printing(resp));
447 string_sprintf("Callout verification failed:\n%s", resp);
449 /* Hard rejection ends the process */
451 if (resp[0] == '5') /* Address rejected */
459 break; /* host_list */
462 cancel_cutthrough_connection("incompatible connection");
467 /*************************************************
468 * Do callout verification for an address *
469 *************************************************/
471 /* This function is called from verify_address() when the address has routed to
472 a host list, and a callout has been requested. Callouts are expensive; that is
473 why a cache is used to improve the efficiency.
476 addr the address that's been routed
477 host_list the list of hosts to try
478 tf the transport feedback block
480 ifstring "interface" option from transport, or NULL
481 portstring "port" option from transport, or NULL
482 protocolstring "protocol" option from transport, or NULL
483 callout the per-command callout timeout
484 callout_overall the overall callout timeout (if < 0 use 4*callout)
485 callout_connect the callout connection timeout (if < 0 use callout)
486 options the verification options - these bits are used:
487 vopt_is_recipient => this is a recipient address
488 vopt_callout_no_cache => don't use callout cache
489 vopt_callout_fullpm => if postmaster check, do full one
490 vopt_callout_random => do the "random" thing
491 vopt_callout_recipsender => use real sender for recipient
492 vopt_callout_recippmaster => use postmaster for recipient
493 se_mailfrom MAIL FROM address for sender verify; NULL => ""
494 pm_mailfrom if non-NULL, do the postmaster check with this sender
496 Returns: OK/FAIL/DEFER
500 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
501 int callout, int callout_overall, int callout_connect, int options,
502 uschar *se_mailfrom, uschar *pm_mailfrom)
505 int old_domain_cache_result = ccache_accept;
508 uschar *from_address;
509 uschar *random_local_part = NULL;
510 const uschar *save_deliver_domain = deliver_domain;
511 uschar **failure_ptr = options & vopt_is_recipient
512 ? &recipient_verify_failure : &sender_verify_failure;
513 dbdata_callout_cache new_domain_record;
514 dbdata_callout_cache_address new_address_record;
515 time_t callout_start_time;
517 new_domain_record.result = ccache_unknown;
518 new_domain_record.postmaster_result = ccache_unknown;
519 new_domain_record.random_result = ccache_unknown;
521 memset(&new_address_record, 0, sizeof(new_address_record));
523 /* For a recipient callout, the key used for the address cache record must
524 include the sender address if we are using the real sender in the callout,
525 because that may influence the result of the callout. */
527 if (options & vopt_is_recipient)
528 if (options & vopt_callout_recipsender)
530 from_address = sender_address;
531 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
532 if (cutthrough.delivery) options |= vopt_callout_no_cache;
534 else if (options & vopt_callout_recippmaster)
536 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
537 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
538 qualify_domain_sender);
543 address_key = addr->address;
546 /* For a sender callout, we must adjust the key if the mailfrom address is not
551 from_address = se_mailfrom ? se_mailfrom : US"";
552 address_key = *from_address
553 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
556 if (cached_callout_lookup(addr, address_key, from_address,
557 &options, &pm_mailfrom, &yield, failure_ptr,
558 &new_domain_record, &old_domain_cache_result))
561 if (!addr->transport)
563 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
565 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
566 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
567 addr->transport->name, addr->transport->driver_name);
570 smtp_transport_options_block *ob =
571 (smtp_transport_options_block *)addr->transport->options_block;
574 /* The information wasn't available in the cache, so we have to do a real
575 callout and save the result in the cache for next time, unless no_cache is set,
576 or unless we have a previously cached negative random result. If we are to test
577 with a random local part, ensure that such a local part is available. If not,
578 log the fact, but carry on without randomising. */
580 if (options & vopt_callout_random && callout_random_local_part)
581 if (!(random_local_part = expand_string(callout_random_local_part)))
582 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
583 "callout_random_local_part: %s", expand_string_message);
585 /* Default the connect and overall callout timeouts if not set, and record the
586 time we are starting so that we can enforce it. */
588 if (callout_overall < 0) callout_overall = 4 * callout;
589 if (callout_connect < 0) callout_connect = callout;
590 callout_start_time = time(NULL);
592 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
593 output because a callout might take some time. When PIPELINING is active and
594 there are many recipients, the total time for doing lots of callouts can add up
595 and cause the client to time out. So in this case we forgo the PIPELINING
598 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
600 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
601 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
603 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
604 and we are holding a cutthrough conn open, we can just append the rcpt to
605 that conn for verification purposes (and later delivery also). Simplest
606 coding means skipping this whole loop and doing the append separately. */
608 /* Can we re-use an open cutthrough connection? */
609 if ( cutthrough.fd >= 0
610 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
611 == vopt_callout_recipsender
612 && !random_local_part
615 done = cutthrough_multi(addr, host_list, tf, &yield);
617 /* If we did not use a cached connection, make connections to the hosts
618 and do real callouts. The list of hosts is passed in as an argument. */
620 for (host = host_list; host && !done; host = host->next)
624 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
629 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
634 /* Check the overall callout timeout */
636 if (time(NULL) - callout_start_time >= callout_overall)
638 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
642 /* Set IPv4 or IPv6 */
644 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
646 /* Expand and interpret the interface and port strings. The latter will not
647 be used if there is a host-specific port (e.g. from a manualroute router).
648 This has to be delayed till now, because they may expand differently for
649 different hosts. If there's a failure, log it, but carry on with the
652 deliver_host = host->name;
653 deliver_host_address = host->address;
654 deliver_host_port = host->port;
655 deliver_domain = addr->domain;
656 transport_name = addr->transport->name;
658 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
660 || !smtp_get_port(tf->port, addr, &port, US"callout")
662 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
667 sx.host_af = host_af,
669 sx.interface = interface;
670 sx.helo_data = tf->helo_data;
671 sx.tblock = addr->transport;
674 tls_retry_connection:
675 /* Set the address state so that errors are recorded in it */
677 addr->transport_return = PENDING_DEFER;
678 ob->connect_timeout = callout_connect;
679 ob->command_timeout = callout;
681 /* Get the channel set up ready for a message (MAIL FROM being the next
682 SMTP command to send. If we tried TLS but it failed, try again without
685 yield = smtp_setup_conn(&sx, FALSE);
688 && addr->basic_errno == ERRNO_TLSFAILURE
689 && ob->tls_tempfail_tryclear
690 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
693 log_write(0, LOG_MAIN, "TLS session failure:"
694 " callout unencrypted to %s [%s] (not in hosts_require_tls)",
695 host->name, host->address);
696 addr->transport_return = PENDING_DEFER;
697 yield = smtp_setup_conn(&sx, TRUE);
702 errno = addr->basic_errno;
703 transport_name = NULL;
704 deliver_host = deliver_host_address = NULL;
705 deliver_domain = save_deliver_domain;
707 /* Failure to accept HELO is cached; this blocks the whole domain for all
708 senders. I/O errors and defer responses are not cached. */
710 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
712 setflag(addr, af_verify_nsfail);
713 new_domain_record.result = ccache_reject;
721 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
722 the AUTH info for logging */
724 addr->authenticator = client_authenticator;
725 addr->auth_id = client_authenticated_id;
727 sx.from_addr = from_address;
728 sx.first_addr = sx.sync_addr = addr;
729 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
731 sx.completed_addr = FALSE;
733 new_domain_record.result =
734 old_domain_cache_result == ccache_reject_mfnull
735 ? ccache_reject_mfnull : ccache_accept;
737 /* Do the random local part check first. Temporarily replace the recipient
738 with the "random" value */
740 if (random_local_part)
742 uschar * main_address = addr->address;
743 const uschar * rcpt_domain = addr->domain;
746 uschar * errstr = NULL;
747 if ( testflag(addr, af_utf8_downcvt)
748 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
752 addr->message = errstr;
753 errno = ERRNO_EXPANDFAIL;
754 setflag(addr, af_verify_nsfail);
756 rcpt_domain = US""; /*XXX errorhandling! */
760 /* This would be ok for 1st rcpt of a cutthrough (XXX do we have a count?) , but no way to
761 handle a subsequent because of the RSET. So refuse to support any. */
762 cancel_cutthrough_connection("random-recipient");
764 addr->address = string_sprintf("%s@%.1000s",
765 random_local_part, rcpt_domain);
768 /* If accepted, we aren't going to do any further tests below.
769 Otherwise, cache a real negative response, and get back to the right
770 state to send RCPT. Unless there's some problem such as a dropped
771 connection, we expect to succeed, because the commands succeeded above.
772 However, some servers drop the connection after responding to an
773 invalid recipient, so on (any) error we drop and remake the connection.
774 XXX We don't care about that for postmaster_full. Should we?
776 XXX could we add another flag to the context, and have the common
777 code emit the RSET too? Even pipelined after the RCPT...
778 Then the main-verify call could use it if there's to be a subsequent
780 The sync_responses() would need to be taught about it and we'd
781 need another return code filtering out to here.
784 /* Remember when we last did a random test */
785 new_domain_record.random_stamp = time(NULL);
787 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
788 switch(addr->transport_return)
791 new_domain_record.random_result = ccache_accept;
792 yield = OK; /* Only usable result we can return */
796 new_domain_record.random_result = ccache_reject;
798 /* Between each check, issue RSET, because some servers accept only
799 one recipient after MAIL FROM:<>.
800 XXX We don't care about that for postmaster_full. Should we? */
803 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
804 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
809 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
810 random_local_part = NULL;
812 tls_close(FALSE, TRUE);
814 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
815 (void)close(sx.inblock.sock);
816 sx.inblock.sock = sx.outblock.sock = -1;
817 #ifndef DISABLE_EVENT
818 (void) event_raise(addr->transport->event_action,
819 US"tcp:close", NULL);
821 addr->address = main_address;
822 addr->transport_return = PENDING_DEFER;
823 sx.first_addr = sx.sync_addr = addr;
826 sx.completed_addr = FALSE;
827 goto tls_retry_connection;
830 /* Re-setup for main verify, or for the error message when failing */
831 addr->address = main_address;
832 addr->transport_return = PENDING_DEFER;
833 sx.first_addr = sx.sync_addr = addr;
836 sx.completed_addr = FALSE;
841 /* Main verify. If the host is accepting all local parts, as determined
842 by the "random" check, we don't need to waste time doing any further
848 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
850 case 0: switch(addr->transport_return) /* ok so far */
852 case PENDING_OK: done = TRUE;
853 new_address_record.result = ccache_accept;
855 case FAIL: done = TRUE;
857 *failure_ptr = US"recipient";
858 new_address_record.result = ccache_reject;
864 case -1: /* MAIL response error */
865 *failure_ptr = US"mail";
866 if (errno == 0 && sx.buffer[0] == '5')
868 setflag(addr, af_verify_nsfail);
869 if (from_address[0] == 0)
870 new_domain_record.result = ccache_reject_mfnull;
873 /* non-MAIL read i/o error */
874 /* non-MAIL response timeout */
875 /* internal error; channel still usable */
876 default: break; /* transmit failed */
880 addr->auth_sndr = client_authenticated_sender;
882 deliver_host = deliver_host_address = NULL;
883 deliver_domain = save_deliver_domain;
885 /* Do postmaster check if requested; if a full check is required, we
886 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
888 if (done && pm_mailfrom)
890 /* Could possibly shift before main verify, just above, and be ok
891 for cutthrough. But no way to handle a subsequent rcpt, so just
893 cancel_cutthrough_connection("postmaster verify");
894 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
896 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
897 && smtp_read_response(&sx.inblock, sx.buffer,
898 sizeof(sx.buffer), '2', callout);
902 uschar * main_address = addr->address;
904 /*XXX oops, affixes */
905 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
906 addr->transport_return = PENDING_DEFER;
908 sx.from_addr = pm_mailfrom;
909 sx.first_addr = sx.sync_addr = addr;
912 sx.completed_addr = FALSE;
914 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
915 && addr->transport_return == PENDING_OK
919 done = (options & vopt_callout_fullpm) != 0
920 && smtp_write_command(&sx.outblock, FALSE,
921 "RCPT TO:<postmaster>\r\n") >= 0
922 && smtp_read_response(&sx.inblock, sx.buffer,
923 sizeof(sx.buffer), '2', callout);
925 /* Sort out the cache record */
927 new_domain_record.postmaster_stamp = time(NULL);
930 new_domain_record.postmaster_result = ccache_accept;
931 else if (errno == 0 && sx.buffer[0] == '5')
933 *failure_ptr = US"postmaster";
934 setflag(addr, af_verify_pmfail);
935 new_domain_record.postmaster_result = ccache_reject;
938 addr->address = main_address;
941 /* For any failure of the main check, other than a negative response, we just
942 close the connection and carry on. We can identify a negative response by the
943 fact that errno is zero. For I/O errors it will be non-zero
945 Set up different error texts for logging and for sending back to the caller
946 as an SMTP response. Log in all cases, using a one-line format. For sender
947 callouts, give a full response to the caller, but for recipient callouts,
948 don't give the IP address because this may be an internal host whose identity
949 is not to be widely broadcast. */
955 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
956 sx.send_quit = FALSE;
962 extern int acl_where; /* src/acl.c */
964 addr->message = string_sprintf(
965 "response to \"EHLO\" did not include SMTPUTF8");
966 addr->user_message = acl_where == ACL_WHERE_RCPT
967 ? US"533 no support for internationalised mailbox name"
968 : US"550 mailbox unavailable";
975 sx.send_quit = FALSE;
979 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
981 /*XXX test here is ugly; seem to have a split of responsibility for
982 building this message. Need to reationalise. Where is it done
983 before here, and when not?
984 Not == 5xx resp to MAIL on main-verify
986 if (!addr->message) addr->message =
987 string_sprintf("response to \"%s\" was: %s",
988 big_buffer, string_printing(sx.buffer));
990 addr->user_message = options & vopt_is_recipient
991 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
992 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
993 host->address, big_buffer, sx.buffer);
995 /* Hard rejection ends the process */
997 if (sx.buffer[0] == '5') /* Address rejected */
1005 /* End the SMTP conversation and close the connection. */
1007 /* Cutthrough - on a successful connect and recipient-verify with
1008 use-sender and we are 1st rcpt and have no cutthrough conn so far
1009 here is where we want to leave the conn open */
1010 if ( cutthrough.delivery
1014 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1015 == vopt_callout_recipsender
1016 && !random_local_part
1018 && cutthrough.fd < 0
1022 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for cutthrough delivery\n");
1024 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1025 cutthrough.nrcpt = 1;
1026 cutthrough.interface = interface;
1027 cutthrough.host = *host;
1028 cutthrough.addr = *addr; /* Save the address_item for later logging */
1029 cutthrough.addr.next = NULL;
1030 cutthrough.addr.host_used = &cutthrough.host;
1032 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1034 ctblock.buffer = ctbuffer;
1035 ctblock.buffersize = sizeof(ctbuffer);
1036 ctblock.ptr = ctbuffer;
1037 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1038 ctblock.sock = cutthrough.fd;
1042 /* Ensure no cutthrough on multiple address verifies */
1043 if (options & vopt_callout_recipsender)
1044 cancel_cutthrough_connection("not usable for cutthrough");
1047 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1049 /* Wait a short time for response, and discard it */
1050 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1054 if (sx.inblock.sock >= 0)
1057 tls_close(FALSE, TRUE);
1059 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1060 (void)close(sx.inblock.sock);
1061 sx.inblock.sock = sx.outblock.sock = -1;
1062 #ifndef DISABLE_EVENT
1063 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1068 if (!done || yield != OK)
1069 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1071 } /* Loop through all hosts, while !done */
1074 /* If we get here with done == TRUE, a successful callout happened, and yield
1075 will be set OK or FAIL according to the response to the RCPT command.
1076 Otherwise, we looped through the hosts but couldn't complete the business.
1077 However, there may be domain-specific information to cache in both cases. */
1079 if (!(options & vopt_callout_no_cache))
1080 cache_callout_write(&new_domain_record, addr->domain,
1081 done, &new_address_record, address_key);
1083 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1084 temporary error. If there was only one host, and a response was received, leave
1085 it alone if supplying details. Otherwise, give a generic response. */
1089 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1090 options & vopt_is_recipient ? "recipient" : "sender");
1093 addr->message = host_list->next || !addr->message
1094 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1096 addr->user_message = smtp_return_error_details
1097 ? string_sprintf("%s for <%s>.\n"
1098 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1099 "they may be permanently unreachable from this server. In the latter case,\n%s",
1100 dullmsg, addr->address,
1101 options & vopt_is_recipient
1102 ? "the address will never be accepted."
1103 : "you need to change the address or create an MX record for its domain\n"
1104 "if it is supposed to be generally accessible from the Internet.\n"
1105 "Talk to your mail administrator for details.")
1108 /* Force a specific error code */
1110 addr->basic_errno = ERRNO_CALLOUTDEFER;
1113 /* Come here from within the cache-reading code on fast-track exit. */
1116 tls_modify_variables(&tls_in);
1122 /* Called after recipient-acl to get a cutthrough connection open when
1123 one was requested and a recipient-verify wasn't subsequently done.
1126 open_cutthrough_connection( address_item * addr )
1131 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1132 /* We must use a copy of the address for verification, because it might
1136 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1137 rcpt_count > 1 ? "more" : "start");
1138 rc = verify_address(&addr2, NULL,
1139 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1140 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1142 addr->message = addr2.message;
1143 addr->user_message = addr2.user_message;
1144 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1150 /* Send given number of bytes from the buffer */
1152 cutthrough_send(int n)
1154 if(cutthrough.fd < 0)
1159 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1161 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1164 transport_count += n;
1165 ctblock.ptr= ctblock.buffer;
1169 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1176 _cutthrough_puts(uschar * cp, int n)
1180 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1181 if(!cutthrough_send(ctblock.buffersize))
1184 *ctblock.ptr++ = *cp++;
1189 /* Buffered output of counted data block. Return boolean success */
1191 cutthrough_puts(uschar * cp, int n)
1193 if (cutthrough.fd < 0) return TRUE;
1194 if (_cutthrough_puts(cp, n)) return TRUE;
1195 cancel_cutthrough_connection("transmit failed");
1201 _cutthrough_flush_send(void)
1203 int n= ctblock.ptr-ctblock.buffer;
1206 if(!cutthrough_send(n))
1212 /* Send out any bufferred output. Return boolean success. */
1214 cutthrough_flush_send(void)
1216 if (_cutthrough_flush_send()) return TRUE;
1217 cancel_cutthrough_connection("transmit failed");
1223 cutthrough_put_nl(void)
1225 return cutthrough_puts(US"\r\n", 2);
1229 /* Get and check response from cutthrough target */
1231 cutthrough_response(char expect, uschar ** copy, int timeout)
1233 smtp_inblock inblock;
1234 uschar inbuffer[4096];
1235 uschar responsebuffer[4096];
1237 inblock.buffer = inbuffer;
1238 inblock.buffersize = sizeof(inbuffer);
1239 inblock.ptr = inbuffer;
1240 inblock.ptrend = inbuffer;
1241 inblock.sock = cutthrough.fd;
1242 /* this relies on (inblock.sock == tls_out.active) */
1243 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1244 cancel_cutthrough_connection("target timeout on read");
1249 *copy = cp = string_copy(responsebuffer);
1250 /* Trim the trailing end of line */
1251 cp += Ustrlen(responsebuffer);
1252 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1253 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1256 return responsebuffer[0];
1260 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1262 cutthrough_predata(void)
1264 if(cutthrough.fd < 0)
1267 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1268 cutthrough_puts(US"DATA\r\n", 6);
1269 cutthrough_flush_send();
1271 /* Assume nothing buffered. If it was it gets ignored. */
1272 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1276 /* fd and tctx args only to match write_chunk() */
1278 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1281 while(s && (s2 = Ustrchr(s, '\n')))
1283 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1291 /* Buffered send of headers. Return success boolean. */
1292 /* Expands newlines to wire format (CR,NL). */
1293 /* Also sends header-terminating blank line. */
1295 cutthrough_headers_send(void)
1299 if(cutthrough.fd < 0)
1302 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1303 but having a separate buffered-output function (for now)
1305 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1307 tctx.tblock = cutthrough.addr.transport;
1308 tctx.addr = &cutthrough.addr;
1309 tctx.check_string = US".";
1310 tctx.escape_string = US"..";
1311 tctx.options = topt_use_crlf;
1313 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1316 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1322 close_cutthrough_connection(const char * why)
1324 if(cutthrough.fd >= 0)
1326 /* We could be sending this after a bunch of data, but that is ok as
1327 the only way to cancel the transfer in dataphase is to drop the tcp
1328 conn before the final dot.
1330 ctblock.ptr = ctbuffer;
1331 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1332 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1333 _cutthrough_flush_send();
1335 /* Wait a short time for response, and discard it */
1336 cutthrough_response('2', NULL, 1);
1339 tls_close(FALSE, TRUE);
1341 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1342 (void)close(cutthrough.fd);
1344 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1346 ctblock.ptr = ctbuffer;
1350 cancel_cutthrough_connection(const char * why)
1352 close_cutthrough_connection(why);
1353 cutthrough.delivery = FALSE;
1359 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1360 Log an OK response as a transmission.
1361 Close the connection.
1362 Return smtp response-class digit.
1365 cutthrough_finaldot(void)
1368 address_item * addr;
1369 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1371 /* Assume data finshed with new-line */
1372 if( !cutthrough_puts(US".", 1)
1373 || !cutthrough_put_nl()
1374 || !cutthrough_flush_send()
1376 return cutthrough.addr.message;
1378 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1379 for (addr = &cutthrough.addr; addr; addr = addr->next)
1381 addr->message = cutthrough.addr.message;
1385 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1386 close_cutthrough_connection("delivered");
1390 delivery_log(LOG_MAIN, addr, 0,
1391 US"tmp-reject from cutthrough after DATA:");
1395 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1396 US"rejected after DATA:");
1403 return cutthrough.addr.message;
1408 /*************************************************
1409 * Copy error to toplevel address *
1410 *************************************************/
1412 /* This function is used when a verify fails or defers, to ensure that the
1413 failure or defer information is in the original toplevel address. This applies
1414 when an address is redirected to a single new address, and the failure or
1415 deferral happens to the child address.
1418 vaddr the verify address item
1419 addr the final address item
1422 Returns: the value of YIELD
1426 copy_error(address_item *vaddr, address_item *addr, int yield)
1430 vaddr->message = addr->message;
1431 vaddr->user_message = addr->user_message;
1432 vaddr->basic_errno = addr->basic_errno;
1433 vaddr->more_errno = addr->more_errno;
1434 vaddr->prop.address_data = addr->prop.address_data;
1435 copyflag(vaddr, addr, af_pass_message);
1443 /**************************************************
1444 * printf that automatically handles TLS if needed *
1445 ***************************************************/
1447 /* This function is used by verify_address() as a substitute for all fprintf()
1448 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1449 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1450 that assumes that we always use the smtp_out FILE* when not using TLS or the
1451 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1452 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1456 f the candidate FILE* to write to
1457 format format string
1458 ... optional arguments
1464 static void PRINTF_FUNCTION(2,3)
1465 respond_printf(FILE *f, const char *format, ...)
1469 va_start(ap, format);
1470 if (smtp_out && (f == smtp_out))
1471 smtp_vprintf(format, ap);
1473 vfprintf(f, format, ap);
1479 /*************************************************
1480 * Verify an email address *
1481 *************************************************/
1483 /* This function is used both for verification (-bv and at other times) and
1484 address testing (-bt), which is indicated by address_test_mode being set.
1487 vaddr contains the address to verify; the next field in this block
1489 f if not NULL, write the result to this file
1490 options various option bits:
1491 vopt_fake_sender => this sender verify is not for the real
1492 sender (it was verify=sender=xxxx or an address from a
1493 header line) - rewriting must not change sender_address
1494 vopt_is_recipient => this is a recipient address, otherwise
1495 it's a sender address - this affects qualification and
1496 rewriting and messages from callouts
1497 vopt_qualify => qualify an unqualified address; else error
1498 vopt_expn => called from SMTP EXPN command
1499 vopt_success_on_redirect => when a new address is generated
1500 the verification instantly succeeds
1502 These ones are used by do_callout() -- the options variable
1505 vopt_callout_fullpm => if postmaster check, do full one
1506 vopt_callout_no_cache => don't use callout cache
1507 vopt_callout_random => do the "random" thing
1508 vopt_callout_recipsender => use real sender for recipient
1509 vopt_callout_recippmaster => use postmaster for recipient
1511 callout if > 0, specifies that callout is required, and gives timeout
1512 for individual commands
1513 callout_overall if > 0, gives overall timeout for the callout function;
1514 if < 0, a default is used (see do_callout())
1515 callout_connect the connection timeout for callouts
1516 se_mailfrom when callout is requested to verify a sender, use this
1517 in MAIL FROM; NULL => ""
1518 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1519 thing and use this as the sender address (may be "")
1521 routed if not NULL, set TRUE if routing succeeded, so we can
1522 distinguish between routing failed and callout failed
1524 Returns: OK address verified
1525 FAIL address failed to verify
1526 DEFER can't tell at present
1530 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1531 int callout_overall, int callout_connect, uschar *se_mailfrom,
1532 uschar *pm_mailfrom, BOOL *routed)
1535 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1536 BOOL expn = (options & vopt_expn) != 0;
1537 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1540 int verify_type = expn? v_expn :
1541 address_test_mode? v_none :
1542 options & vopt_is_recipient? v_recipient : v_sender;
1543 address_item *addr_list;
1544 address_item *addr_new = NULL;
1545 address_item *addr_remote = NULL;
1546 address_item *addr_local = NULL;
1547 address_item *addr_succeed = NULL;
1548 uschar **failure_ptr = options & vopt_is_recipient
1549 ? &recipient_verify_failure : &sender_verify_failure;
1550 uschar *ko_prefix, *cr;
1551 uschar *address = vaddr->address;
1552 uschar *save_sender;
1553 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1555 /* Clear, just in case */
1557 *failure_ptr = NULL;
1559 /* Set up a prefix and suffix for error message which allow us to use the same
1560 output statements both in EXPN mode (where an SMTP response is needed) and when
1561 debugging with an output file. */
1565 ko_prefix = US"553 ";
1568 else ko_prefix = cr = US"";
1570 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1572 if (parse_find_at(address) == NULL)
1574 if ((options & vopt_qualify) == 0)
1577 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1578 ko_prefix, address, cr);
1579 *failure_ptr = US"qualify";
1582 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1587 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1588 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1591 /* Rewrite and report on it. Clear the domain and local part caches - these
1592 may have been set by domains and local part tests during an ACL. */
1594 if (global_rewrite_rules != NULL)
1596 uschar *old = address;
1597 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1598 global_rewrite_rules, rewrite_existflags);
1601 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1602 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1603 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1607 /* If this is the real sender address, we must update sender_address at
1608 this point, because it may be referred to in the routers. */
1610 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1611 sender_address = address;
1613 /* If the address was rewritten to <> no verification can be done, and we have
1614 to return OK. This rewriting is permitted only for sender addresses; for other
1615 addresses, such rewriting fails. */
1617 if (address[0] == 0) return OK;
1619 /* Flip the legacy TLS-related variables over to the outbound set in case
1620 they're used in the context of a transport used by verification. Reset them
1621 at exit from this routine (so no returns allowed from here on). */
1623 tls_modify_variables(&tls_out);
1625 /* Save a copy of the sender address for re-instating if we change it to <>
1626 while verifying a sender address (a nice bit of self-reference there). */
1628 save_sender = sender_address;
1630 /* Observability variable for router/transport use */
1632 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1634 /* Update the address structure with the possibly qualified and rewritten
1635 address. Set it up as the starting address on the chain of new addresses. */
1637 vaddr->address = address;
1640 /* We need a loop, because an address can generate new addresses. We must also
1641 cope with generated pipes and files at the top level. (See also the code and
1642 comment in deliver.c.) However, it is usually the case that the router for
1643 user's .forward files has its verify flag turned off.
1645 If an address generates more than one child, the loop is used only when
1646 full_info is set, and this can only be set locally. Remote enquiries just get
1647 information about the top level address, not anything that it generated. */
1652 address_item *addr = addr_new;
1654 addr_new = addr->next;
1659 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1660 debug_printf("Considering %s\n", addr->address);
1663 /* Handle generated pipe, file or reply addresses. We don't get these
1664 when handling EXPN, as it does only one level of expansion. */
1666 if (testflag(addr, af_pfr))
1673 if (addr->address[0] == '>')
1675 allow = testflag(addr, af_allow_reply);
1676 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1680 allow = (addr->address[0] == '|')?
1681 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1682 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1685 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1686 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1687 "%s\n", addr->message);
1689 fprintf(f, "\n transport = %s\n", addr->transport->name);
1691 fprintf(f, " *** forbidden ***\n");
1696 /* Just in case some router parameter refers to it. */
1698 return_path = addr->prop.errors_address
1699 ? addr->prop.errors_address : sender_address;
1701 /* Split the address into domain and local part, handling the %-hack if
1702 necessary, and then route it. While routing a sender address, set
1703 $sender_address to <> because that is what it will be if we were trying to
1704 send a bounce to the sender. */
1706 if (routed) *routed = FALSE;
1707 if ((rc = deliver_split_address(addr)) == OK)
1709 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1710 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1711 &addr_succeed, verify_type);
1712 sender_address = save_sender; /* Put back the real sender */
1715 /* If routing an address succeeded, set the flag that remembers, for use when
1716 an ACL cached a sender verify (in case a callout fails). Then if routing set
1717 up a list of hosts or the transport has a host list, and the callout option
1718 is set, and we aren't in a host checking run, do the callout verification,
1719 and set another flag that notes that a callout happened. */
1723 if (routed) *routed = TRUE;
1726 transport_instance * tp;
1727 host_item * host_list = addr->host_list;
1729 /* Make up some data for use in the case where there is no remote
1732 transport_feedback tf = {
1733 NULL, /* interface (=> any) */
1734 US"smtp", /* port */
1735 US"smtp", /* protocol */
1737 US"$smtp_active_hostname", /* helo_data */
1738 FALSE, /* hosts_override */
1739 FALSE, /* hosts_randomize */
1740 FALSE, /* gethostbyname */
1741 TRUE, /* qualify_single */
1742 FALSE /* search_parents */
1745 /* If verification yielded a remote transport, we want to use that
1746 transport's options, so as to mimic what would happen if we were really
1747 sending a message to this address. */
1749 if ((tp = addr->transport) && !tp->info->local)
1751 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1753 /* If the transport has hosts and the router does not, or if the
1754 transport is configured to override the router's hosts, we must build a
1755 host list of the transport's hosts, and find the IP addresses */
1757 if (tf.hosts && (!host_list || tf.hosts_override))
1760 const uschar *save_deliver_domain = deliver_domain;
1761 uschar *save_deliver_localpart = deliver_localpart;
1763 host_list = NULL; /* Ignore the router's hosts */
1765 deliver_domain = addr->domain;
1766 deliver_localpart = addr->local_part;
1767 s = expand_string(tf.hosts);
1768 deliver_domain = save_deliver_domain;
1769 deliver_localpart = save_deliver_localpart;
1773 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1774 "\"%s\" in %s transport for callout: %s", tf.hosts,
1775 tp->name, expand_string_message);
1780 host_item *host, *nexthost;
1781 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1783 /* Just ignore failures to find a host address. If we don't manage
1784 to find any addresses, the callout will defer. Note that more than
1785 one address may be found for a single host, which will result in
1786 additional host items being inserted into the chain. Hence we must
1787 save the next host first. */
1789 flags = HOST_FIND_BY_A;
1790 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1791 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1793 for (host = host_list; host; host = nexthost)
1795 nexthost = host->next;
1796 if (tf.gethostbyname ||
1797 string_is_ip_address(host->name, NULL) != 0)
1798 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1801 dnssec_domains * dnssec_domains = NULL;
1802 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1804 smtp_transport_options_block * ob =
1805 (smtp_transport_options_block *) tp->options_block;
1806 dnssec_domains = &ob->dnssec;
1809 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1810 dnssec_domains, NULL, NULL);
1817 /* Can only do a callout if we have at least one host! If the callout
1818 fails, it will have set ${sender,recipient}_verify_failure. */
1822 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1823 if (host_checking && !host_checking_callout)
1826 debug_printf("... callout omitted by default when host testing\n"
1827 "(Use -bhc if you want the callouts to happen.)\n");
1832 deliver_set_expansions(addr);
1834 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1835 callout_connect, options, se_mailfrom, pm_mailfrom);
1840 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1841 "transport provided a host list\n");
1846 /* Otherwise, any failure is a routing failure */
1848 else *failure_ptr = US"route";
1850 /* A router may return REROUTED if it has set up a child address as a result
1851 of a change of domain name (typically from widening). In this case we always
1852 want to continue to verify the new child. */
1854 if (rc == REROUTED) continue;
1856 /* Handle hard failures */
1863 address_item *p = addr->parent;
1865 respond_printf(f, "%s%s %s", ko_prefix,
1866 full_info ? addr->address : address,
1867 address_test_mode ? "is undeliverable" : "failed to verify");
1868 if (!expn && admin_user)
1870 if (addr->basic_errno > 0)
1871 respond_printf(f, ": %s", strerror(addr->basic_errno));
1873 respond_printf(f, ": %s", addr->message);
1876 /* Show parents iff doing full info */
1878 if (full_info) while (p)
1880 respond_printf(f, "%s\n <-- %s", cr, p->address);
1883 respond_printf(f, "%s\n", cr);
1885 cancel_cutthrough_connection("routing hard fail");
1889 yield = copy_error(vaddr, addr, FAIL);
1897 else if (rc == DEFER)
1902 address_item *p = addr->parent;
1903 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1904 full_info? addr->address : address);
1905 if (!expn && admin_user)
1907 if (addr->basic_errno > 0)
1908 respond_printf(f, ": %s", strerror(addr->basic_errno));
1910 respond_printf(f, ": %s", addr->message);
1911 else if (addr->basic_errno <= 0)
1912 respond_printf(f, ": unknown error");
1915 /* Show parents iff doing full info */
1917 if (full_info) while (p)
1919 respond_printf(f, "%s\n <-- %s", cr, p->address);
1922 respond_printf(f, "%s\n", cr);
1924 cancel_cutthrough_connection("routing soft fail");
1928 yield = copy_error(vaddr, addr, DEFER);
1931 if (yield == OK) yield = DEFER;
1934 /* If we are handling EXPN, we do not want to continue to route beyond
1935 the top level (whose address is in "address"). */
1939 uschar *ok_prefix = US"250-";
1942 if (!addr_local && !addr_remote)
1943 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1945 respond_printf(f, "250 <%s>\r\n", address);
1949 address_item *addr2 = addr_new;
1950 addr_new = addr2->next;
1951 if (!addr_new) ok_prefix = US"250 ";
1952 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1958 /* Successful routing other than EXPN. */
1962 /* Handle successful routing when short info wanted. Otherwise continue for
1963 other (generated) addresses. Short info is the operational case. Full info
1964 can be requested only when debug_selector != 0 and a file is supplied.
1966 There is a conflict between the use of aliasing as an alternate email
1967 address, and as a sort of mailing list. If an alias turns the incoming
1968 address into just one address (e.g. J.Caesar->jc44) you may well want to
1969 carry on verifying the generated address to ensure it is valid when
1970 checking incoming mail. If aliasing generates multiple addresses, you
1971 probably don't want to do this. Exim therefore treats the generation of
1972 just a single new address as a special case, and continues on to verify the
1973 generated address. */
1975 if ( !full_info /* Stop if short info wanted AND */
1976 && ( ( !addr_new /* No new address OR */
1977 || addr_new->next /* More than one new address OR */
1978 || testflag(addr_new, af_pfr) /* New address is pfr */
1981 ( addr_new /* At least one new address AND */
1982 && success_on_redirect /* success_on_redirect is set */
1986 if (f) fprintf(f, "%s %s\n",
1987 address, address_test_mode ? "is deliverable" : "verified");
1989 /* If we have carried on to verify a child address, we want the value
1990 of $address_data to be that of the child */
1992 vaddr->prop.address_data = addr->prop.address_data;
1994 /* If stopped because more than one new address, cannot cutthrough */
1996 if (addr_new && addr_new->next)
1997 cancel_cutthrough_connection("multiple addresses from routing");
2003 } /* Loop for generated addresses */
2005 /* Display the full results of the successful routing, including any generated
2006 addresses. Control gets here only when full_info is set, which requires f not
2007 to be NULL, and this occurs only when a top-level verify is called with the
2008 debugging switch on.
2010 If there are no local and no remote addresses, and there were no pipes, files,
2011 or autoreplies, and there were no errors or deferments, the message is to be
2012 discarded, usually because of the use of :blackhole: in an alias file. */
2014 if (allok && !addr_local && !addr_remote)
2016 fprintf(f, "mail to %s is discarded\n", address);
2020 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2023 address_item *addr = addr_list;
2024 address_item *p = addr->parent;
2025 transport_instance * tp = addr->transport;
2027 addr_list = addr->next;
2029 fprintf(f, "%s", CS addr->address);
2030 #ifdef EXPERIMENTAL_SRS
2031 if(addr->prop.srs_sender)
2032 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2035 /* If the address is a duplicate, show something about it. */
2037 if (!testflag(addr, af_pfr))
2040 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2041 fprintf(f, " [duplicate, would not be delivered]");
2042 else tree_add_duplicate(addr->unique, addr);
2045 /* Now show its parents */
2047 for (p = addr->parent; p; p = p->parent)
2048 fprintf(f, "\n <-- %s", p->address);
2051 /* Show router, and transport */
2053 fprintf(f, "router = %s, transport = %s\n",
2054 addr->router->name, tp ? tp->name : US"unset");
2056 /* Show any hosts that are set up by a router unless the transport
2057 is going to override them; fiddle a bit to get a nice format. */
2059 if (addr->host_list && tp && !tp->overrides_hosts)
2064 for (h = addr->host_list; h; h = h->next)
2065 { /* get max lengths of host names, addrs */
2066 int len = Ustrlen(h->name);
2067 if (len > maxlen) maxlen = len;
2068 len = h->address ? Ustrlen(h->address) : 7;
2069 if (len > maxaddlen) maxaddlen = len;
2071 for (h = addr->host_list; h; h = h->next)
2073 fprintf(f, " host %-*s ", maxlen, h->name);
2076 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2077 else if (tp->info->local)
2078 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2080 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2082 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2083 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2084 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2085 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2091 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2092 the -bv or -bt case). */
2096 tls_modify_variables(&tls_in);
2104 /*************************************************
2105 * Check headers for syntax errors *
2106 *************************************************/
2108 /* This function checks those header lines that contain addresses, and verifies
2109 that all the addresses therein are syntactially correct.
2112 msgptr where to put an error message
2119 verify_check_headers(uschar **msgptr)
2125 for (h = header_list; h != NULL && yield == OK; h = h->next)
2127 if (h->type != htype_from &&
2128 h->type != htype_reply_to &&
2129 h->type != htype_sender &&
2130 h->type != htype_to &&
2131 h->type != htype_cc &&
2132 h->type != htype_bcc)
2135 colon = Ustrchr(h->text, ':');
2137 while (isspace(*s)) s++;
2139 /* Loop for multiple addresses in the header, enabling group syntax. Note
2140 that we have to reset this after the header has been scanned. */
2142 parse_allow_group = TRUE;
2146 uschar *ss = parse_find_address_end(s, FALSE);
2147 uschar *recipient, *errmess;
2148 int terminator = *ss;
2149 int start, end, domain;
2151 /* Temporarily terminate the string at this point, and extract the
2152 operative address within, allowing group syntax. */
2155 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2158 /* Permit an unqualified address only if the message is local, or if the
2159 sending host is configured to be permitted to send them. */
2161 if (recipient != NULL && domain == 0)
2163 if (h->type == htype_from || h->type == htype_sender)
2165 if (!allow_unqualified_sender) recipient = NULL;
2169 if (!allow_unqualified_recipient) recipient = NULL;
2171 if (recipient == NULL) errmess = US"unqualified address not permitted";
2174 /* It's an error if no address could be extracted, except for the special
2175 case of an empty address. */
2177 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2179 uschar *verb = US"is";
2184 /* Arrange not to include any white space at the end in the
2185 error message or the header name. */
2187 while (t > s && isspace(t[-1])) t--;
2188 while (tt > h->text && isspace(tt[-1])) tt--;
2190 /* Add the address that failed to the error message, since in a
2191 header with very many addresses it is sometimes hard to spot
2192 which one is at fault. However, limit the amount of address to
2193 quote - cases have been seen where, for example, a missing double
2194 quote in a humungous To: header creates an "address" that is longer
2195 than string_sprintf can handle. */
2204 /* deconst cast ok as we're passing a non-const to string_printing() */
2205 *msgptr = US string_printing(
2206 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2207 errmess, tt - h->text, h->text, verb, len, s));
2210 break; /* Out of address loop */
2213 /* Advance to the next address */
2215 s = ss + (terminator? 1:0);
2216 while (isspace(*s)) s++;
2217 } /* Next address */
2219 parse_allow_group = FALSE;
2220 parse_found_group = FALSE;
2221 } /* Next header unless yield has been set FALSE */
2227 /*************************************************
2228 * Check header names for 8-bit characters *
2229 *************************************************/
2231 /* This function checks for invalid characters in header names. See
2232 RFC 5322, 2.2. and RFC 6532, 3.
2235 msgptr where to put an error message
2242 verify_check_header_names_ascii(uschar **msgptr)
2247 for (h = header_list; h != NULL; h = h->next)
2249 colon = Ustrchr(h->text, ':');
2250 for(s = h->text; s < colon; s++)
2252 if ((*s < 33) || (*s > 126))
2254 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2255 colon - h->text, h->text);
2263 /*************************************************
2264 * Check for blind recipients *
2265 *************************************************/
2267 /* This function checks that every (envelope) recipient is mentioned in either
2268 the To: or Cc: header lines, thus detecting blind carbon copies.
2270 There are two ways of scanning that could be used: either scan the header lines
2271 and tick off the recipients, or scan the recipients and check the header lines.
2272 The original proposed patch did the former, but I have chosen to do the latter,
2273 because (a) it requires no memory and (b) will use fewer resources when there
2274 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2277 Returns: OK if there are no blind recipients
2278 FAIL if there is at least one blind recipient
2282 verify_check_notblind(void)
2285 for (i = 0; i < recipients_count; i++)
2289 uschar *address = recipients_list[i].address;
2291 for (h = header_list; !found && h != NULL; h = h->next)
2295 if (h->type != htype_to && h->type != htype_cc) continue;
2297 colon = Ustrchr(h->text, ':');
2299 while (isspace(*s)) s++;
2301 /* Loop for multiple addresses in the header, enabling group syntax. Note
2302 that we have to reset this after the header has been scanned. */
2304 parse_allow_group = TRUE;
2308 uschar *ss = parse_find_address_end(s, FALSE);
2309 uschar *recipient,*errmess;
2310 int terminator = *ss;
2311 int start, end, domain;
2313 /* Temporarily terminate the string at this point, and extract the
2314 operative address within, allowing group syntax. */
2317 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2320 /* If we found a valid recipient that has a domain, compare it with the
2321 envelope recipient. Local parts are compared case-sensitively, domains
2322 case-insensitively. By comparing from the start with length "domain", we
2323 include the "@" at the end, which ensures that we are comparing the whole
2324 local part of each address. */
2326 if (recipient != NULL && domain != 0)
2328 found = Ustrncmp(recipient, address, domain) == 0 &&
2329 strcmpic(recipient + domain, address + domain) == 0;
2333 /* Advance to the next address */
2335 s = ss + (terminator? 1:0);
2336 while (isspace(*s)) s++;
2337 } /* Next address */
2339 parse_allow_group = FALSE;
2340 parse_found_group = FALSE;
2341 } /* Next header (if found is false) */
2343 if (!found) return FAIL;
2344 } /* Next recipient */
2351 /*************************************************
2352 * Find if verified sender *
2353 *************************************************/
2355 /* Usually, just a single address is verified as the sender of the message.
2356 However, Exim can be made to verify other addresses as well (often related in
2357 some way), and this is useful in some environments. There may therefore be a
2358 chain of such addresses that have previously been tested. This function finds
2359 whether a given address is on the chain.
2361 Arguments: the address to be verified
2362 Returns: pointer to an address item, or NULL
2366 verify_checked_sender(uschar *sender)
2369 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2370 if (Ustrcmp(sender, addr->address) == 0) break;
2378 /*************************************************
2379 * Get valid header address *
2380 *************************************************/
2382 /* Scan the originator headers of the message, looking for an address that
2383 verifies successfully. RFC 822 says:
2385 o The "Sender" field mailbox should be sent notices of
2386 any problems in transport or delivery of the original
2387 messages. If there is no "Sender" field, then the
2388 "From" field mailbox should be used.
2390 o If the "Reply-To" field exists, then the reply should
2391 go to the addresses indicated in that field and not to
2392 the address(es) indicated in the "From" field.
2394 So we check a Sender field if there is one, else a Reply_to field, else a From
2395 field. As some strange messages may have more than one of these fields,
2396 especially if they are resent- fields, check all of them if there is more than
2400 user_msgptr points to where to put a user error message
2401 log_msgptr points to where to put a log error message
2402 callout timeout for callout check (passed to verify_address())
2403 callout_overall overall callout timeout (ditto)
2404 callout_connect connect callout timeout (ditto)
2405 se_mailfrom mailfrom for verify; NULL => ""
2406 pm_mailfrom sender for pm callout check (passed to verify_address())
2407 options callout options (passed to verify_address())
2408 verrno where to put the address basic_errno
2410 If log_msgptr is set to something without setting user_msgptr, the caller
2411 normally uses log_msgptr for both things.
2413 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2414 FAIL is given if no appropriate headers are found
2418 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2419 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2420 uschar *pm_mailfrom, int options, int *verrno)
2422 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2427 for (i = 0; i < 3 && !done; i++)
2430 for (h = header_list; h != NULL && !done; h = h->next)
2432 int terminator, new_ok;
2433 uschar *s, *ss, *endname;
2435 if (h->type != header_types[i]) continue;
2436 s = endname = Ustrchr(h->text, ':') + 1;
2438 /* Scan the addresses in the header, enabling group syntax. Note that we
2439 have to reset this after the header has been scanned. */
2441 parse_allow_group = TRUE;
2445 address_item *vaddr;
2447 while (isspace(*s) || *s == ',') s++;
2448 if (*s == 0) break; /* End of header */
2450 ss = parse_find_address_end(s, FALSE);
2452 /* The terminator is a comma or end of header, but there may be white
2453 space preceding it (including newline for the last address). Move back
2454 past any white space so we can check against any cached envelope sender
2455 address verifications. */
2457 while (isspace(ss[-1])) ss--;
2461 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2462 (int)(endname - h->text), h->text, s);
2464 /* See if we have already verified this address as an envelope sender,
2465 and if so, use the previous answer. */
2467 vaddr = verify_checked_sender(s);
2469 if (vaddr != NULL && /* Previously checked */
2470 (callout <= 0 || /* No callout needed; OR */
2471 vaddr->special_action > 256)) /* Callout was done */
2473 new_ok = vaddr->special_action & 255;
2474 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2475 *ss = terminator; /* Restore shortened string */
2478 /* Otherwise we run the verification now. We must restore the shortened
2479 string before running the verification, so the headers are correct, in
2480 case there is any rewriting. */
2484 int start, end, domain;
2485 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2490 /* If we found an empty address, just carry on with the next one, but
2491 kill the message. */
2493 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2500 /* If verification failed because of a syntax error, fail this
2501 function, and ensure that the failing address gets added to the error
2504 if (address == NULL)
2507 while (ss > s && isspace(ss[-1])) ss--;
2508 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2509 "scanning for sender: %s in \"%.*s\"",
2510 endname - h->text, h->text, *log_msgptr, ss - s, s);
2516 /* Else go ahead with the sender verification. But it isn't *the*
2517 sender of the message, so set vopt_fake_sender to stop sender_address
2518 being replaced after rewriting or qualification. */
2522 vaddr = deliver_make_addr(address, FALSE);
2523 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2524 callout, callout_overall, callout_connect, se_mailfrom,
2529 /* We now have the result, either newly found, or cached. If we are
2530 giving out error details, set a specific user error. This means that the
2531 last of these will be returned to the user if all three fail. We do not
2532 set a log message - the generic one below will be used. */
2536 *verrno = vaddr->basic_errno;
2537 if (smtp_return_error_details)
2539 *user_msgptr = string_sprintf("Rejected after DATA: "
2540 "could not verify \"%.*s\" header address\n%s: %s",
2541 endname - h->text, h->text, vaddr->address, vaddr->message);
2545 /* Success or defer */
2554 if (new_ok == DEFER) yield = DEFER;
2556 /* Move on to any more addresses in the header */
2559 } /* Next address */
2561 parse_allow_group = FALSE;
2562 parse_found_group = FALSE;
2563 } /* Next header, unless done */
2564 } /* Next header type unless done */
2566 if (yield == FAIL && *log_msgptr == NULL)
2567 *log_msgptr = US"there is no valid sender in any header line";
2569 if (yield == DEFER && *log_msgptr == NULL)
2570 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2578 /*************************************************
2579 * Get RFC 1413 identification *
2580 *************************************************/
2582 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2583 the timeout is set to zero, then the query is not done. There may also be lists
2584 of hosts and nets which are exempt. To guard against malefactors sending
2585 non-printing characters which could, for example, disrupt a message's headers,
2586 make sure the string consists of printing characters only.
2589 port the port to connect to; usually this is IDENT_PORT (113), but when
2590 running in the test harness with -bh a different value is used.
2594 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2598 verify_get_ident(int port)
2600 int sock, host_af, qlen;
2601 int received_sender_port, received_interface_port, n;
2603 uschar buffer[2048];
2605 /* Default is no ident. Check whether we want to do an ident check for this
2608 sender_ident = NULL;
2609 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2612 DEBUG(D_ident) debug_printf("doing ident callback\n");
2614 /* Set up a connection to the ident port of the remote host. Bind the local end
2615 to the incoming interface address. If the sender host address is an IPv6
2616 address, the incoming interface address will also be IPv6. */
2618 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2619 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2621 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2623 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2628 if (ip_connect(sock, host_af, sender_host_address, port,
2629 rfc1413_query_timeout, TRUE) < 0)
2631 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2632 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2633 sender_host_address);
2635 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2636 sender_host_address, strerror(errno));
2640 /* Construct and send the query. */
2642 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2643 qlen = Ustrlen(buffer);
2644 if (send(sock, buffer, qlen, 0) < 0)
2646 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2650 /* Read a response line. We put it into the rest of the buffer, using several
2651 recv() calls if necessary. */
2659 int size = sizeof(buffer) - (p - buffer);
2661 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2662 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2663 if (count <= 0) goto END_OFF; /* Read error or EOF */
2665 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2666 generous, and accept a plain \n terminator as well. The only illegal
2669 for (pp = p; pp < p + count; pp++)
2671 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2674 if (pp[-1] == '\r') pp--;
2676 goto GOT_DATA; /* Break out of both loops */
2680 /* Reached the end of the data without finding \n. Let the loop continue to
2681 read some more, if there is room. */
2688 /* We have received a line of data. Check it carefully. It must start with the
2689 same two port numbers that we sent, followed by data as defined by the RFC. For
2692 12345 , 25 : USERID : UNIX :root
2694 However, the amount of white space may be different to what we sent. In the
2695 "osname" field there may be several sub-fields, comma separated. The data we
2696 actually want to save follows the third colon. Some systems put leading spaces
2697 in it - we discard those. */
2699 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2700 &received_interface_port, &n) != 2 ||
2701 received_sender_port != sender_host_port ||
2702 received_interface_port != interface_port)
2705 p = buffer + qlen + n;
2706 while(isspace(*p)) p++;
2707 if (*p++ != ':') goto END_OFF;
2708 while(isspace(*p)) p++;
2709 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2711 while(isspace(*p)) p++;
2712 if (*p++ != ':') goto END_OFF;
2713 while (*p != 0 && *p != ':') p++;
2714 if (*p++ == 0) goto END_OFF;
2715 while(isspace(*p)) p++;
2716 if (*p == 0) goto END_OFF;
2718 /* The rest of the line is the data we want. We turn it into printing
2719 characters when we save it, so that it cannot mess up the format of any logging
2720 or Received: lines into which it gets inserted. We keep a maximum of 127
2721 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2723 sender_ident = US string_printing(string_copyn(p, 127));
2724 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2734 /*************************************************
2735 * Match host to a single host-list item *
2736 *************************************************/
2738 /* This function compares a host (name or address) against a single item
2739 from a host list. The host name gets looked up if it is needed and is not
2740 already known. The function is called from verify_check_this_host() via
2741 match_check_list(), which is why most of its arguments are in a single block.
2744 arg the argument block (see below)
2745 ss the host-list item
2746 valueptr where to pass back looked up data, or NULL
2747 error for error message when returning ERROR
2750 host_name (a) the host name, or
2751 (b) NULL, implying use sender_host_name and
2752 sender_host_aliases, looking them up if required, or
2753 (c) the empty string, meaning that only IP address matches
2755 host_address the host address
2756 host_ipv4 the IPv4 address taken from an IPv6 one
2760 DEFER lookup deferred
2761 ERROR (a) failed to find the host name or IP address, or
2762 (b) unknown lookup type specified, or
2763 (c) host name encountered when only IP addresses are
2768 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2770 check_host_block *cb = (check_host_block *)arg;
2773 BOOL iplookup = FALSE;
2774 BOOL isquery = FALSE;
2775 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2780 /* Optimize for the special case when the pattern is "*". */
2782 if (*ss == '*' && ss[1] == 0) return OK;
2784 /* If the pattern is empty, it matches only in the case when there is no host -
2785 this can occur in ACL checking for SMTP input using the -bs option. In this
2786 situation, the host address is the empty string. */
2788 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2789 if (*ss == 0) return FAIL;
2791 /* If the pattern is precisely "@" then match against the primary host name,
2792 provided that host name matching is permitted; if it's "@[]" match against the
2793 local host's IP addresses. */
2799 if (isiponly) return ERROR;
2800 ss = primary_hostname;
2802 else if (Ustrcmp(ss, "@[]") == 0)
2804 ip_address_item *ip;
2805 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2806 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2811 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2812 a (possibly masked) comparison with the current IP address. */
2814 if (string_is_ip_address(ss, &maskoffset) != 0)
2815 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2817 /* The pattern is not an IP address. A common error that people make is to omit
2818 one component of an IPv4 address, either by accident, or believing that, for
2819 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,
2820 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2821 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2822 ancient specification.) To aid in debugging these cases, we give a specific
2823 error if the pattern contains only digits and dots or contains a slash preceded
2824 only by digits and dots (a slash at the start indicates a file name and of
2825 course slashes may be present in lookups, but not preceded only by digits and
2828 for (t = ss; isdigit(*t) || *t == '.'; t++);
2829 if (*t == 0 || (*t == '/' && t != ss))
2831 *error = US"malformed IPv4 address or address mask";
2835 /* See if there is a semicolon in the pattern */
2837 semicolon = Ustrchr(ss, ';');
2839 /* If we are doing an IP address only match, then all lookups must be IP
2840 address lookups, even if there is no "net-". */
2844 iplookup = semicolon != NULL;
2847 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2848 a lookup on a masked IP network, in textual form. We obey this code even if we
2849 have already set iplookup, so as to skip over the "net-" prefix and to set the
2850 mask length. The net- stuff really only applies to single-key lookups where the
2851 key is implicit. For query-style lookups the key is specified in the query.
2852 From release 4.30, the use of net- for query style is no longer needed, but we
2853 retain it for backward compatibility. */
2855 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2858 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2859 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2860 iplookup = (*t++ == '-');
2864 /* Do the IP address lookup if that is indeed what we have */
2872 uschar *filename, *key, *result;
2875 /* Find the search type */
2877 search_type = search_findtype(t, semicolon - t);
2879 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2880 search_error_message);
2882 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2883 is no file name, and the "key" is just the query. For query-style with a file
2884 name, we have to fish the file off the start of the query. For a single-key
2885 lookup, the key is the current IP address, masked appropriately, and
2886 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2887 dot separators instead of colons, except when the lookup type is "iplsearch".
2890 if (mac_islookup(search_type, lookup_absfilequery))
2892 filename = semicolon + 1;
2894 while (*key != 0 && !isspace(*key)) key++;
2895 filename = string_copyn(filename, key - filename);
2896 while (isspace(*key)) key++;
2898 else if (mac_islookup(search_type, lookup_querystyle))
2901 key = semicolon + 1;
2903 else /* Single-key style */
2905 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2907 insize = host_aton(cb->host_address, incoming);
2908 host_mask(insize, incoming, mlen);
2909 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2911 filename = semicolon + 1;
2914 /* Now do the actual lookup; note that there is no search_close() because
2915 of the caching arrangements. */
2917 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2918 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2920 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2921 if (valueptr != NULL) *valueptr = result;
2922 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2925 /* The pattern is not an IP address or network reference of any kind. That is,
2926 it is a host name pattern. If this is an IP only match, there's an error in the
2931 *error = US"cannot match host name in match_ip list";
2935 /* Check the characters of the pattern to see if they comprise only letters,
2936 digits, full stops, and hyphens (the constituents of domain names). Allow
2937 underscores, as they are all too commonly found. Sigh. Also, if
2938 allow_utf8_domains is set, allow top-bit characters. */
2940 for (t = ss; *t != 0; t++)
2941 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2942 (!allow_utf8_domains || *t < 128)) break;
2944 /* If the pattern is a complete domain name, with no fancy characters, look up
2945 its IP address and match against that. Note that a multi-homed host will add
2946 items to the chain. */
2957 /* Using byname rather than bydns here means we cannot determine dnssec
2958 status. On the other hand it is unclear how that could be either
2959 propagated up or enforced. */
2961 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2962 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2965 for (hh = &h; hh != NULL; hh = hh->next)
2967 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2971 if (rc == HOST_FIND_AGAIN) return DEFER;
2972 *error = string_sprintf("failed to find IP address for %s", ss);
2976 /* Almost all subsequent comparisons require the host name, and can be done
2977 using the general string matching function. When this function is called for
2978 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2979 must use sender_host_name and its aliases, looking them up if necessary. */
2981 if (cb->host_name != NULL) /* Explicit host name given */
2982 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2985 /* Host name not given; in principle we need the sender host name and its
2986 aliases. However, for query-style lookups, we do not need the name if the
2987 query does not contain $sender_host_name. From release 4.23, a reference to
2988 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2991 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2993 const uschar *affix;
2994 int partial, affixlen, starflags, id;
2997 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3000 if (id < 0) /* Unknown lookup type */
3002 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3003 search_error_message, ss);
3006 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3011 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3014 case DEFER: return DEFER;
3015 default: return FAIL;
3019 /* Not a query-style lookup; must ensure the host name is present, and then we
3020 do a check on the name and all its aliases. */
3022 if (sender_host_name == NULL)
3024 HDEBUG(D_host_lookup)
3025 debug_printf("sender host name required, to match against %s\n", ss);
3026 if (host_lookup_failed || host_name_lookup() != OK)
3028 *error = string_sprintf("failed to find host name for %s",
3029 sender_host_address);;
3032 host_build_sender_fullhost();
3035 /* Match on the sender host name, using the general matching function */
3037 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3041 case DEFER: return DEFER;
3044 /* If there are aliases, try matching on them. */
3046 aliases = sender_host_aliases;
3047 while (*aliases != NULL)
3049 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3052 case DEFER: return DEFER;
3061 /*************************************************
3062 * Check a specific host matches a host list *
3063 *************************************************/
3065 /* This function is passed a host list containing items in a number of
3066 different formats and the identity of a host. Its job is to determine whether
3067 the given host is in the set of hosts defined by the list. The host name is
3068 passed as a pointer so that it can be looked up if needed and not already
3069 known. This is commonly the case when called from verify_check_host() to check
3070 an incoming connection. When called from elsewhere the host name should usually
3073 This function is now just a front end to match_check_list(), which runs common
3074 code for scanning a list. We pass it the check_host() function to perform a
3078 listptr pointer to the host list
3079 cache_bits pointer to cache for named lists, or NULL
3080 host_name the host name or NULL, implying use sender_host_name and
3081 sender_host_aliases, looking them up if required
3082 host_address the IP address
3083 valueptr if not NULL, data from a lookup is passed back here
3085 Returns: OK if the host is in the defined set
3086 FAIL if the host is not in the defined set,
3087 DEFER if a data lookup deferred (not a host lookup)
3089 If the host name was needed in order to make a comparison, and could not be
3090 determined from the IP address, the result is FAIL unless the item
3091 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3094 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3095 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3098 unsigned int *local_cache_bits = cache_bits;
3099 const uschar *save_host_address = deliver_host_address;
3100 check_host_block cb;
3101 cb.host_name = host_name;
3102 cb.host_address = host_address;
3104 if (valueptr != NULL) *valueptr = NULL;
3106 /* If the host address starts off ::ffff: it is an IPv6 address in
3107 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3110 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3111 host_address + 7 : host_address;
3113 /* During the running of the check, put the IP address into $host_address. In
3114 the case of calls from the smtp transport, it will already be there. However,
3115 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3116 the safe side, any existing setting is preserved, though as I write this
3117 (November 2004) I can't see any cases where it is actually needed. */
3119 deliver_host_address = host_address;
3120 rc = match_check_list(
3121 listptr, /* the list */
3122 0, /* separator character */
3123 &hostlist_anchor, /* anchor pointer */
3124 &local_cache_bits, /* cache pointer */
3125 check_host, /* function for testing */
3126 &cb, /* argument for function */
3127 MCL_HOST, /* type of check */
3128 (host_address == sender_host_address)?
3129 US"host" : host_address, /* text for debugging */
3130 valueptr); /* where to pass back data */
3131 deliver_host_address = save_host_address;
3138 /*************************************************
3139 * Check the given host item matches a list *
3140 *************************************************/
3142 verify_check_given_host(uschar **listptr, host_item *host)
3144 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3147 /*************************************************
3148 * Check the remote host matches a list *
3149 *************************************************/
3151 /* This is a front end to verify_check_this_host(), created because checking
3152 the remote host is a common occurrence. With luck, a good compiler will spot
3153 the tail recursion and optimize it. If there's no host address, this is
3154 command-line SMTP input - check against an empty string for the address.
3157 listptr pointer to the host list
3159 Returns: the yield of verify_check_this_host(),
3160 i.e. OK, FAIL, or DEFER
3164 verify_check_host(uschar **listptr)
3166 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3167 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3174 /*************************************************
3175 * Invert an IP address *
3176 *************************************************/
3178 /* Originally just used for DNS xBL lists, now also used for the
3179 reverse_ip expansion operator.
3182 buffer where to put the answer
3183 address the address to invert
3187 invert_address(uschar *buffer, uschar *address)
3190 uschar *bptr = buffer;
3192 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3193 to the IPv4 part only. */
3195 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3197 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3200 if (host_aton(address, bin) == 1)
3204 for (i = 0; i < 4; i++)
3206 sprintf(CS bptr, "%d.", x & 255);
3207 while (*bptr) bptr++;
3212 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3213 in any DNS black lists, and the format in which they will be looked up is
3214 unknown. This is just a guess. */
3220 for (j = 3; j >= 0; j--)
3223 for (i = 0; i < 8; i++)
3225 sprintf(CS bptr, "%x.", x & 15);
3226 while (*bptr) bptr++;
3233 /* Remove trailing period -- this is needed so that both arbitrary
3234 dnsbl keydomains and inverted addresses may be combined with the
3235 same format string, "%s.%s" */
3242 /*************************************************
3243 * Perform a single dnsbl lookup *
3244 *************************************************/
3246 /* This function is called from verify_check_dnsbl() below. It is also called
3247 recursively from within itself when domain and domain_txt are different
3248 pointers, in order to get the TXT record from the alternate domain.
3251 domain the outer dnsbl domain
3252 domain_txt alternate domain to lookup TXT record on success; when the
3253 same domain is to be used, domain_txt == domain (that is,
3254 the pointers must be identical, not just the text)
3255 keydomain the current keydomain (for debug message)
3256 prepend subdomain to lookup (like keydomain, but
3257 reversed if IP address)
3258 iplist the list of matching IP addresses, or NULL for "any"
3259 bitmask true if bitmask matching is wanted
3260 match_type condition for 'succeed' result
3261 0 => Any RR in iplist (=)
3262 1 => No RR in iplist (!=)
3263 2 => All RRs in iplist (==)
3264 3 => Some RRs not in iplist (!==)
3265 the two bits are defined as MT_NOT and MT_ALL
3266 defer_return what to return for a defer
3268 Returns: OK if lookup succeeded
3273 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3274 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3280 dnsbl_cache_block *cb;
3281 int old_pool = store_pool;
3282 uschar query[256]; /* DNS domain max length */
3284 /* Construct the specific query domainname */
3286 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3288 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3289 "(ignored): %s...", query);
3293 /* Look for this query in the cache. */
3295 if ( (t = tree_search(dnsbl_cache, query))
3296 && (cb = t->data.ptr)->expiry > time(NULL)
3299 /* Previous lookup was cached */
3302 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3305 /* If not cached from a previous lookup, we must do a DNS lookup, and
3306 cache the result in permanent memory. */
3312 store_pool = POOL_PERM;
3316 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3320 { /* Set up a tree entry to cache the lookup */
3321 t = store_get(sizeof(tree_node) + Ustrlen(query));
3322 Ustrcpy(t->name, query);
3323 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3324 (void)tree_insertnode(&dnsbl_cache, t);
3327 /* Do the DNS lookup . */
3329 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3330 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3331 cb->text_set = FALSE;
3335 /* If the lookup succeeded, cache the RHS address. The code allows for
3336 more than one address - this was for complete generality and the possible
3337 use of A6 records. However, A6 records have been reduced to experimental
3338 status (August 2001) and may die out. So they may never get used at all,
3339 let alone in dnsbl records. However, leave the code here, just in case.
3341 Quite apart from one A6 RR generating multiple addresses, there are DNS
3342 lists that return more than one A record, so we must handle multiple
3343 addresses generated in that way as well.
3345 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3346 or some suitably far-future time if none were found. */
3348 if (cb->rc == DNS_SUCCEED)
3351 dns_address **addrp = &(cb->rhs);
3352 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3354 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3356 if (rr->type == T_A)
3358 dns_address *da = dns_address_from_rr(&dnsa, rr);
3362 while (da->next != NULL) da = da->next;
3363 addrp = &(da->next);
3364 if (ttl > rr->ttl) ttl = rr->ttl;
3369 /* If we didn't find any A records, change the return code. This can
3370 happen when there is a CNAME record but there are no A records for what
3373 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3376 cb->expiry = time(NULL)+ttl;
3377 store_pool = old_pool;
3380 /* We now have the result of the DNS lookup, either newly done, or cached
3381 from a previous call. If the lookup succeeded, check against the address
3382 list if there is one. This may be a positive equality list (introduced by
3383 "="), a negative equality list (introduced by "!="), a positive bitmask
3384 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3386 if (cb->rc == DNS_SUCCEED)
3388 dns_address *da = NULL;
3389 uschar *addlist = cb->rhs->address;
3391 /* For A and AAAA records, there may be multiple addresses from multiple
3392 records. For A6 records (currently not expected to be used) there may be
3393 multiple addresses from a single record. */
3395 for (da = cb->rhs->next; da != NULL; da = da->next)
3396 addlist = string_sprintf("%s, %s", addlist, da->address);
3398 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3401 /* Address list check; this can be either for equality, or via a bitmask.
3402 In the latter case, all the bits must match. */
3406 for (da = cb->rhs; da != NULL; da = da->next)
3410 const uschar *ptr = iplist;
3413 /* Handle exact matching */
3417 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3419 if (Ustrcmp(CS da->address, ip) == 0) break;
3423 /* Handle bitmask matching */
3430 /* At present, all known DNS blocking lists use A records, with
3431 IPv4 addresses on the RHS encoding the information they return. I
3432 wonder if this will linger on as the last vestige of IPv4 when IPv6
3433 is ubiquitous? Anyway, for now we use paranoia code to completely
3434 ignore IPv6 addresses. The default mask is 0, which always matches.
3435 We change this only for IPv4 addresses in the list. */
3437 if (host_aton(da->address, address) == 1) mask = address[0];
3439 /* Scan the returned addresses, skipping any that are IPv6 */
3441 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3443 if (host_aton(ip, address) != 1) continue;
3444 if ((address[0] & mask) == address[0]) break;
3450 (a) An IP address in an any ('=') list matched, or
3451 (b) No IP address in an all ('==') list matched
3453 then we're done searching. */
3455 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3458 /* If da == NULL, either
3460 (a) No IP address in an any ('=') list matched, or
3461 (b) An IP address in an all ('==') list didn't match
3463 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3466 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3474 res = US"was no match";
3477 res = US"was an exclude match";
3480 res = US"was an IP address that did not match";
3483 res = US"were no IP addresses that did not match";
3486 debug_printf("=> but we are not accepting this block class because\n");
3487 debug_printf("=> there %s for %s%c%s\n",
3489 ((match_type & MT_ALL) == 0)? "" : "=",
3490 bitmask? '&' : '=', iplist);
3496 /* Either there was no IP list, or the record matched, implying that the
3497 domain is on the list. We now want to find a corresponding TXT record. If an
3498 alternate domain is specified for the TXT record, call this function
3499 recursively to look that up; this has the side effect of re-checking that
3500 there is indeed an A record at the alternate domain. */
3502 if (domain_txt != domain)
3503 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3504 FALSE, match_type, defer_return);
3506 /* If there is no alternate domain, look up a TXT record in the main domain
3507 if it has not previously been cached. */
3511 cb->text_set = TRUE;
3512 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3515 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3517 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3518 if (rr->type == T_TXT) break;
3521 int len = (rr->data)[0];
3522 if (len > 511) len = 127;
3523 store_pool = POOL_PERM;
3524 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3525 store_pool = old_pool;
3530 dnslist_value = addlist;
3531 dnslist_text = cb->text;
3535 /* There was a problem with the DNS lookup */
3537 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3539 log_write(L_dnslist_defer, LOG_MAIN,
3540 "DNS list lookup defer (probably timeout) for %s: %s", query,
3541 (defer_return == OK)? US"assumed in list" :
3542 (defer_return == FAIL)? US"assumed not in list" :
3543 US"returned DEFER");
3544 return defer_return;
3547 /* No entry was found in the DNS; continue for next domain */
3551 debug_printf("DNS lookup for %s failed\n", query);
3552 debug_printf("=> that means %s is not listed at %s\n",
3562 /*************************************************
3563 * Check host against DNS black lists *
3564 *************************************************/
3566 /* This function runs checks against a list of DNS black lists, until one
3567 matches. Each item on the list can be of the form
3569 domain=ip-address/key
3571 The domain is the right-most domain that is used for the query, for example,
3572 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3573 if the DNS lookup returns a matching IP address. Several addresses may be
3574 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3576 If no key is given, what is looked up in the domain is the inverted IP address
3577 of the current client host. If a key is given, it is used to construct the
3578 domain for the lookup. For example:
3580 dsn.rfc-ignorant.org/$sender_address_domain
3582 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3583 then we check for a TXT record for an error message, and if found, save its
3584 value in $dnslist_text. We also cache everything in a tree, to optimize
3587 The TXT record is normally looked up in the same domain as the A record, but
3588 when many lists are combined in a single DNS domain, this will not be a very
3589 specific message. It is possible to specify a different domain for looking up
3590 TXT records; this is given before the main domain, comma-separated. For
3593 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3594 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3596 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3598 Note: an address for testing RBL is 192.203.178.39
3599 Note: an address for testing DUL is 192.203.178.4
3600 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3604 listptr the domain/address/data list
3605 log_msgptr log message on error
3607 Returns: OK successful lookup (i.e. the address is on the list), or
3608 lookup deferred after +include_unknown
3609 FAIL name not found, or no data found for the given type, or
3610 lookup deferred after +exclude_unknown (default)
3611 DEFER lookup failure, if +defer_unknown was set
3615 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3618 int defer_return = FAIL;
3619 const uschar *list = *listptr;
3622 uschar buffer[1024];
3623 uschar revadd[128]; /* Long enough for IPv6 address */
3625 /* Indicate that the inverted IP address is not yet set up */
3629 /* In case this is the first time the DNS resolver is being used. */
3631 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3633 /* Loop through all the domains supplied, until something matches */
3635 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3638 BOOL bitmask = FALSE;
3645 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3647 /* Deal with special values that change the behaviour on defer */
3649 if (domain[0] == '+')
3651 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3652 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3653 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3655 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3660 /* See if there's explicit data to be looked up */
3662 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3664 /* See if there's a list of addresses supplied after the domain name. This is
3665 introduced by an = or a & character; if preceded by = we require all matches
3666 and if preceded by ! we invert the result. */
3668 if (!(iplist = Ustrchr(domain, '=')))
3671 iplist = Ustrchr(domain, '&');
3674 if (iplist) /* Found either = or & */
3676 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3678 match_type |= MT_NOT;
3682 *iplist++ = 0; /* Terminate domain, move on */
3684 /* If we found = (bitmask == FALSE), check for == or =& */
3686 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3688 bitmask = *iplist++ == '&';
3689 match_type |= MT_ALL;
3694 /* If there is a comma in the domain, it indicates that a second domain for
3695 looking up TXT records is provided, before the main domain. Otherwise we must
3696 set domain_txt == domain. */
3698 domain_txt = domain;
3699 comma = Ustrchr(domain, ',');
3706 /* Check that what we have left is a sensible domain name. There is no reason
3707 why these domains should in fact use the same syntax as hosts and email
3708 domains, but in practice they seem to. However, there is little point in
3709 actually causing an error here, because that would no doubt hold up incoming
3710 mail. Instead, I'll just log it. */
3712 for (s = domain; *s != 0; s++)
3714 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3716 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3717 "strange characters - is this right?", domain);
3722 /* Check the alternate domain if present */
3724 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3726 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3728 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3729 "strange characters - is this right?", domain_txt);
3734 /* If there is no key string, construct the query by adding the domain name
3735 onto the inverted host address, and perform a single DNS lookup. */
3739 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3741 *log_msgptr = string_sprintf
3742 ("cannot test auto-keyed dnslists condition in %s ACL",
3743 acl_wherenames[where]);
3746 if (sender_host_address == NULL) return FAIL; /* can never match */
3747 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3748 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3749 iplist, bitmask, match_type, defer_return);
3752 dnslist_domain = string_copy(domain_txt);
3753 dnslist_matched = string_copy(sender_host_address);
3754 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3755 sender_host_address, dnslist_domain);
3757 if (rc != FAIL) return rc; /* OK or DEFER */
3760 /* If there is a key string, it can be a list of domains or IP addresses to
3761 be concatenated with the main domain. */
3768 uschar keybuffer[256];
3769 uschar keyrevadd[128];
3771 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3772 sizeof(keybuffer))) != NULL)
3774 uschar *prepend = keydomain;
3776 if (string_is_ip_address(keydomain, NULL) != 0)
3778 invert_address(keyrevadd, keydomain);
3779 prepend = keyrevadd;
3782 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3783 bitmask, match_type, defer_return);
3787 dnslist_domain = string_copy(domain_txt);
3788 dnslist_matched = string_copy(keydomain);
3789 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3790 keydomain, dnslist_domain);
3794 /* If the lookup deferred, remember this fact. We keep trying the rest
3795 of the list to see if we get a useful result, and if we don't, we return
3796 DEFER at the end. */
3798 if (rc == DEFER) defer = TRUE;
3799 } /* continue with next keystring domain/address */
3801 if (defer) return DEFER;
3803 } /* continue with next dnsdb outer domain */
3810 /* End of verify.c */