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;
794 new_domain_record.random_result = ccache_reject;
796 /* Between each check, issue RSET, because some servers accept only
797 one recipient after MAIL FROM:<>.
798 XXX We don't care about that for postmaster_full. Should we? */
801 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
802 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
807 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
808 random_local_part = NULL;
810 tls_close(FALSE, TRUE);
812 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
813 (void)close(sx.inblock.sock);
814 sx.inblock.sock = sx.outblock.sock = -1;
815 #ifndef DISABLE_EVENT
816 (void) event_raise(addr->transport->event_action,
817 US"tcp:close", NULL);
819 addr->address = main_address;
820 addr->transport_return = PENDING_DEFER;
821 sx.first_addr = sx.sync_addr = addr;
824 sx.completed_addr = FALSE;
825 goto tls_retry_connection;
828 /* Re-setup for main verify, or for the error message when failing */
829 addr->address = main_address;
830 addr->transport_return = PENDING_DEFER;
831 sx.first_addr = sx.sync_addr = addr;
834 sx.completed_addr = FALSE;
839 /* Main verify. If the host is accepting all local parts, as determined
840 by the "random" check, we don't need to waste time doing any further
846 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
848 case 0: switch(addr->transport_return) /* ok so far */
850 case PENDING_OK: done = TRUE;
851 new_address_record.result = ccache_accept;
853 case FAIL: done = TRUE;
855 *failure_ptr = US"recipient";
856 new_address_record.result = ccache_reject;
862 case -1: /* MAIL response error */
863 *failure_ptr = US"mail";
864 if (errno == 0 && sx.buffer[0] == '5')
866 setflag(addr, af_verify_nsfail);
867 if (from_address[0] == 0)
868 new_domain_record.result = ccache_reject_mfnull;
871 /* non-MAIL read i/o error */
872 /* non-MAIL response timeout */
873 /* internal error; channel still usable */
874 default: break; /* transmit failed */
878 addr->auth_sndr = client_authenticated_sender;
880 deliver_host = deliver_host_address = NULL;
881 deliver_domain = save_deliver_domain;
883 /* Do postmaster check if requested; if a full check is required, we
884 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
886 if (done && pm_mailfrom)
888 /* Could possibly shift before main verify, just above, and be ok
889 for cutthrough. But no way to handle a subsequent rcpt, so just
891 cancel_cutthrough_connection("postmaster verify");
892 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
894 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
895 && smtp_read_response(&sx.inblock, sx.buffer,
896 sizeof(sx.buffer), '2', callout);
900 uschar * main_address = addr->address;
902 /*XXX oops, affixes */
903 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
904 addr->transport_return = PENDING_DEFER;
906 sx.from_addr = pm_mailfrom;
907 sx.first_addr = sx.sync_addr = addr;
910 sx.completed_addr = FALSE;
912 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
913 && addr->transport_return == PENDING_OK
917 done = (options & vopt_callout_fullpm) != 0
918 && smtp_write_command(&sx.outblock, FALSE,
919 "RCPT TO:<postmaster>\r\n") >= 0
920 && smtp_read_response(&sx.inblock, sx.buffer,
921 sizeof(sx.buffer), '2', callout);
923 /* Sort out the cache record */
925 new_domain_record.postmaster_stamp = time(NULL);
928 new_domain_record.postmaster_result = ccache_accept;
929 else if (errno == 0 && sx.buffer[0] == '5')
931 *failure_ptr = US"postmaster";
932 setflag(addr, af_verify_pmfail);
933 new_domain_record.postmaster_result = ccache_reject;
936 addr->address = main_address;
939 /* For any failure of the main check, other than a negative response, we just
940 close the connection and carry on. We can identify a negative response by the
941 fact that errno is zero. For I/O errors it will be non-zero
943 Set up different error texts for logging and for sending back to the caller
944 as an SMTP response. Log in all cases, using a one-line format. For sender
945 callouts, give a full response to the caller, but for recipient callouts,
946 don't give the IP address because this may be an internal host whose identity
947 is not to be widely broadcast. */
953 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
954 sx.send_quit = FALSE;
960 extern int acl_where; /* src/acl.c */
962 addr->message = string_sprintf(
963 "response to \"EHLO\" did not include SMTPUTF8");
964 addr->user_message = acl_where == ACL_WHERE_RCPT
965 ? US"533 no support for internationalised mailbox name"
966 : US"550 mailbox unavailable";
973 sx.send_quit = FALSE;
977 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
979 /*XXX test here is ugly; seem to have a split of responsibility for
980 building this message. Need to reationalise. Where is it done
981 before here, and when not?
982 Not == 5xx resp to MAIL on main-verify
984 if (!addr->message) addr->message =
985 string_sprintf("response to \"%s\" was: %s",
986 big_buffer, string_printing(sx.buffer));
988 addr->user_message = options & vopt_is_recipient
989 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
990 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
991 host->address, big_buffer, sx.buffer);
993 /* Hard rejection ends the process */
995 if (sx.buffer[0] == '5') /* Address rejected */
1003 /* End the SMTP conversation and close the connection. */
1005 /* Cutthrough - on a successful connect and recipient-verify with
1006 use-sender and we are 1st rcpt and have no cutthrough conn so far
1007 here is where we want to leave the conn open */
1008 if ( cutthrough.delivery
1012 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1013 == vopt_callout_recipsender
1014 && !random_local_part
1016 && cutthrough.fd < 0
1020 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for cutthrough delivery\n");
1022 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1023 cutthrough.nrcpt = 1;
1024 cutthrough.interface = interface;
1025 cutthrough.host = *host;
1026 cutthrough.addr = *addr; /* Save the address_item for later logging */
1027 cutthrough.addr.next = NULL;
1028 cutthrough.addr.host_used = &cutthrough.host;
1030 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1032 ctblock.buffer = ctbuffer;
1033 ctblock.buffersize = sizeof(ctbuffer);
1034 ctblock.ptr = ctbuffer;
1035 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1036 ctblock.sock = cutthrough.fd;
1040 /* Ensure no cutthrough on multiple address verifies */
1041 if (options & vopt_callout_recipsender)
1042 cancel_cutthrough_connection("not usable for cutthrough");
1045 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1047 /* Wait a short time for response, and discard it */
1048 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1052 if (sx.inblock.sock >= 0)
1055 tls_close(FALSE, TRUE);
1057 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1058 (void)close(sx.inblock.sock);
1059 sx.inblock.sock = sx.outblock.sock = -1;
1060 #ifndef DISABLE_EVENT
1061 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1066 if (!done || yield != OK)
1067 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1069 } /* Loop through all hosts, while !done */
1072 /* If we get here with done == TRUE, a successful callout happened, and yield
1073 will be set OK or FAIL according to the response to the RCPT command.
1074 Otherwise, we looped through the hosts but couldn't complete the business.
1075 However, there may be domain-specific information to cache in both cases. */
1077 if (!(options & vopt_callout_no_cache))
1078 cache_callout_write(&new_domain_record, addr->domain,
1079 done, &new_address_record, address_key);
1081 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1082 temporary error. If there was only one host, and a response was received, leave
1083 it alone if supplying details. Otherwise, give a generic response. */
1087 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1088 options & vopt_is_recipient ? "recipient" : "sender");
1091 addr->message = host_list->next || !addr->message
1092 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1094 addr->user_message = smtp_return_error_details
1095 ? string_sprintf("%s for <%s>.\n"
1096 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1097 "they may be permanently unreachable from this server. In the latter case,\n%s",
1098 dullmsg, addr->address,
1099 options & vopt_is_recipient
1100 ? "the address will never be accepted."
1101 : "you need to change the address or create an MX record for its domain\n"
1102 "if it is supposed to be generally accessible from the Internet.\n"
1103 "Talk to your mail administrator for details.")
1106 /* Force a specific error code */
1108 addr->basic_errno = ERRNO_CALLOUTDEFER;
1111 /* Come here from within the cache-reading code on fast-track exit. */
1114 tls_modify_variables(&tls_in);
1120 /* Called after recipient-acl to get a cutthrough connection open when
1121 one was requested and a recipient-verify wasn't subsequently done.
1124 open_cutthrough_connection( address_item * addr )
1129 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1130 /* We must use a copy of the address for verification, because it might
1134 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1135 rcpt_count > 1 ? "more" : "start");
1136 rc = verify_address(&addr2, NULL,
1137 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1138 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1140 addr->message = addr2.message;
1141 addr->user_message = addr2.user_message;
1142 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1148 /* Send given number of bytes from the buffer */
1150 cutthrough_send(int n)
1152 if(cutthrough.fd < 0)
1157 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1159 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1162 transport_count += n;
1163 ctblock.ptr= ctblock.buffer;
1167 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1174 _cutthrough_puts(uschar * cp, int n)
1178 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1179 if(!cutthrough_send(ctblock.buffersize))
1182 *ctblock.ptr++ = *cp++;
1187 /* Buffered output of counted data block. Return boolean success */
1189 cutthrough_puts(uschar * cp, int n)
1191 if (cutthrough.fd < 0) return TRUE;
1192 if (_cutthrough_puts(cp, n)) return TRUE;
1193 cancel_cutthrough_connection("transmit failed");
1199 _cutthrough_flush_send(void)
1201 int n= ctblock.ptr-ctblock.buffer;
1204 if(!cutthrough_send(n))
1210 /* Send out any bufferred output. Return boolean success. */
1212 cutthrough_flush_send(void)
1214 if (_cutthrough_flush_send()) return TRUE;
1215 cancel_cutthrough_connection("transmit failed");
1221 cutthrough_put_nl(void)
1223 return cutthrough_puts(US"\r\n", 2);
1227 /* Get and check response from cutthrough target */
1229 cutthrough_response(char expect, uschar ** copy, int timeout)
1231 smtp_inblock inblock;
1232 uschar inbuffer[4096];
1233 uschar responsebuffer[4096];
1235 inblock.buffer = inbuffer;
1236 inblock.buffersize = sizeof(inbuffer);
1237 inblock.ptr = inbuffer;
1238 inblock.ptrend = inbuffer;
1239 inblock.sock = cutthrough.fd;
1240 /* this relies on (inblock.sock == tls_out.active) */
1241 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1242 cancel_cutthrough_connection("target timeout on read");
1247 *copy = cp = string_copy(responsebuffer);
1248 /* Trim the trailing end of line */
1249 cp += Ustrlen(responsebuffer);
1250 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1251 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1254 return responsebuffer[0];
1258 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1260 cutthrough_predata(void)
1262 if(cutthrough.fd < 0)
1265 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1266 cutthrough_puts(US"DATA\r\n", 6);
1267 cutthrough_flush_send();
1269 /* Assume nothing buffered. If it was it gets ignored. */
1270 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1274 /* fd and tctx args only to match write_chunk() */
1276 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1279 while(s && (s2 = Ustrchr(s, '\n')))
1281 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1289 /* Buffered send of headers. Return success boolean. */
1290 /* Expands newlines to wire format (CR,NL). */
1291 /* Also sends header-terminating blank line. */
1293 cutthrough_headers_send(void)
1297 if(cutthrough.fd < 0)
1300 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1301 but having a separate buffered-output function (for now)
1303 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1305 tctx.tblock = cutthrough.addr.transport;
1306 tctx.addr = &cutthrough.addr;
1307 tctx.check_string = US".";
1308 tctx.escape_string = US"..";
1309 tctx.options = topt_use_crlf;
1311 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1314 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1320 close_cutthrough_connection(const char * why)
1322 if(cutthrough.fd >= 0)
1324 /* We could be sending this after a bunch of data, but that is ok as
1325 the only way to cancel the transfer in dataphase is to drop the tcp
1326 conn before the final dot.
1328 ctblock.ptr = ctbuffer;
1329 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1330 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1331 _cutthrough_flush_send();
1333 /* Wait a short time for response, and discard it */
1334 cutthrough_response('2', NULL, 1);
1337 tls_close(FALSE, TRUE);
1339 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1340 (void)close(cutthrough.fd);
1342 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1344 ctblock.ptr = ctbuffer;
1348 cancel_cutthrough_connection(const char * why)
1350 close_cutthrough_connection(why);
1351 cutthrough.delivery = FALSE;
1357 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1358 Log an OK response as a transmission.
1359 Close the connection.
1360 Return smtp response-class digit.
1363 cutthrough_finaldot(void)
1366 address_item * addr;
1367 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1369 /* Assume data finshed with new-line */
1370 if( !cutthrough_puts(US".", 1)
1371 || !cutthrough_put_nl()
1372 || !cutthrough_flush_send()
1374 return cutthrough.addr.message;
1376 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1377 for (addr = &cutthrough.addr; addr; addr = addr->next)
1379 addr->message = cutthrough.addr.message;
1383 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1384 close_cutthrough_connection("delivered");
1388 delivery_log(LOG_MAIN, addr, 0,
1389 US"tmp-reject from cutthrough after DATA:");
1393 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1394 US"rejected after DATA:");
1401 return cutthrough.addr.message;
1406 /*************************************************
1407 * Copy error to toplevel address *
1408 *************************************************/
1410 /* This function is used when a verify fails or defers, to ensure that the
1411 failure or defer information is in the original toplevel address. This applies
1412 when an address is redirected to a single new address, and the failure or
1413 deferral happens to the child address.
1416 vaddr the verify address item
1417 addr the final address item
1420 Returns: the value of YIELD
1424 copy_error(address_item *vaddr, address_item *addr, int yield)
1428 vaddr->message = addr->message;
1429 vaddr->user_message = addr->user_message;
1430 vaddr->basic_errno = addr->basic_errno;
1431 vaddr->more_errno = addr->more_errno;
1432 vaddr->prop.address_data = addr->prop.address_data;
1433 copyflag(vaddr, addr, af_pass_message);
1441 /**************************************************
1442 * printf that automatically handles TLS if needed *
1443 ***************************************************/
1445 /* This function is used by verify_address() as a substitute for all fprintf()
1446 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1447 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1448 that assumes that we always use the smtp_out FILE* when not using TLS or the
1449 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1450 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1454 f the candidate FILE* to write to
1455 format format string
1456 ... optional arguments
1462 static void PRINTF_FUNCTION(2,3)
1463 respond_printf(FILE *f, const char *format, ...)
1467 va_start(ap, format);
1468 if (smtp_out && (f == smtp_out))
1469 smtp_vprintf(format, ap);
1471 vfprintf(f, format, ap);
1477 /*************************************************
1478 * Verify an email address *
1479 *************************************************/
1481 /* This function is used both for verification (-bv and at other times) and
1482 address testing (-bt), which is indicated by address_test_mode being set.
1485 vaddr contains the address to verify; the next field in this block
1487 f if not NULL, write the result to this file
1488 options various option bits:
1489 vopt_fake_sender => this sender verify is not for the real
1490 sender (it was verify=sender=xxxx or an address from a
1491 header line) - rewriting must not change sender_address
1492 vopt_is_recipient => this is a recipient address, otherwise
1493 it's a sender address - this affects qualification and
1494 rewriting and messages from callouts
1495 vopt_qualify => qualify an unqualified address; else error
1496 vopt_expn => called from SMTP EXPN command
1497 vopt_success_on_redirect => when a new address is generated
1498 the verification instantly succeeds
1500 These ones are used by do_callout() -- the options variable
1503 vopt_callout_fullpm => if postmaster check, do full one
1504 vopt_callout_no_cache => don't use callout cache
1505 vopt_callout_random => do the "random" thing
1506 vopt_callout_recipsender => use real sender for recipient
1507 vopt_callout_recippmaster => use postmaster for recipient
1509 callout if > 0, specifies that callout is required, and gives timeout
1510 for individual commands
1511 callout_overall if > 0, gives overall timeout for the callout function;
1512 if < 0, a default is used (see do_callout())
1513 callout_connect the connection timeout for callouts
1514 se_mailfrom when callout is requested to verify a sender, use this
1515 in MAIL FROM; NULL => ""
1516 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1517 thing and use this as the sender address (may be "")
1519 routed if not NULL, set TRUE if routing succeeded, so we can
1520 distinguish between routing failed and callout failed
1522 Returns: OK address verified
1523 FAIL address failed to verify
1524 DEFER can't tell at present
1528 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1529 int callout_overall, int callout_connect, uschar *se_mailfrom,
1530 uschar *pm_mailfrom, BOOL *routed)
1533 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1534 BOOL expn = (options & vopt_expn) != 0;
1535 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1538 int verify_type = expn? v_expn :
1539 address_test_mode? v_none :
1540 options & vopt_is_recipient? v_recipient : v_sender;
1541 address_item *addr_list;
1542 address_item *addr_new = NULL;
1543 address_item *addr_remote = NULL;
1544 address_item *addr_local = NULL;
1545 address_item *addr_succeed = NULL;
1546 uschar **failure_ptr = options & vopt_is_recipient
1547 ? &recipient_verify_failure : &sender_verify_failure;
1548 uschar *ko_prefix, *cr;
1549 uschar *address = vaddr->address;
1550 uschar *save_sender;
1551 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1553 /* Clear, just in case */
1555 *failure_ptr = NULL;
1557 /* Set up a prefix and suffix for error message which allow us to use the same
1558 output statements both in EXPN mode (where an SMTP response is needed) and when
1559 debugging with an output file. */
1563 ko_prefix = US"553 ";
1566 else ko_prefix = cr = US"";
1568 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1570 if (parse_find_at(address) == NULL)
1572 if ((options & vopt_qualify) == 0)
1575 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1576 ko_prefix, address, cr);
1577 *failure_ptr = US"qualify";
1580 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1585 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1586 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1589 /* Rewrite and report on it. Clear the domain and local part caches - these
1590 may have been set by domains and local part tests during an ACL. */
1592 if (global_rewrite_rules != NULL)
1594 uschar *old = address;
1595 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1596 global_rewrite_rules, rewrite_existflags);
1599 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1600 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1601 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1605 /* If this is the real sender address, we must update sender_address at
1606 this point, because it may be referred to in the routers. */
1608 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1609 sender_address = address;
1611 /* If the address was rewritten to <> no verification can be done, and we have
1612 to return OK. This rewriting is permitted only for sender addresses; for other
1613 addresses, such rewriting fails. */
1615 if (address[0] == 0) return OK;
1617 /* Flip the legacy TLS-related variables over to the outbound set in case
1618 they're used in the context of a transport used by verification. Reset them
1619 at exit from this routine (so no returns allowed from here on). */
1621 tls_modify_variables(&tls_out);
1623 /* Save a copy of the sender address for re-instating if we change it to <>
1624 while verifying a sender address (a nice bit of self-reference there). */
1626 save_sender = sender_address;
1628 /* Observability variable for router/transport use */
1630 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1632 /* Update the address structure with the possibly qualified and rewritten
1633 address. Set it up as the starting address on the chain of new addresses. */
1635 vaddr->address = address;
1638 /* We need a loop, because an address can generate new addresses. We must also
1639 cope with generated pipes and files at the top level. (See also the code and
1640 comment in deliver.c.) However, it is usually the case that the router for
1641 user's .forward files has its verify flag turned off.
1643 If an address generates more than one child, the loop is used only when
1644 full_info is set, and this can only be set locally. Remote enquiries just get
1645 information about the top level address, not anything that it generated. */
1650 address_item *addr = addr_new;
1652 addr_new = addr->next;
1657 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1658 debug_printf("Considering %s\n", addr->address);
1661 /* Handle generated pipe, file or reply addresses. We don't get these
1662 when handling EXPN, as it does only one level of expansion. */
1664 if (testflag(addr, af_pfr))
1671 if (addr->address[0] == '>')
1673 allow = testflag(addr, af_allow_reply);
1674 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1678 allow = (addr->address[0] == '|')?
1679 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1680 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1683 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1684 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1685 "%s\n", addr->message);
1687 fprintf(f, "\n transport = %s\n", addr->transport->name);
1689 fprintf(f, " *** forbidden ***\n");
1694 /* Just in case some router parameter refers to it. */
1696 return_path = addr->prop.errors_address
1697 ? addr->prop.errors_address : sender_address;
1699 /* Split the address into domain and local part, handling the %-hack if
1700 necessary, and then route it. While routing a sender address, set
1701 $sender_address to <> because that is what it will be if we were trying to
1702 send a bounce to the sender. */
1704 if (routed) *routed = FALSE;
1705 if ((rc = deliver_split_address(addr)) == OK)
1707 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1708 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1709 &addr_succeed, verify_type);
1710 sender_address = save_sender; /* Put back the real sender */
1713 /* If routing an address succeeded, set the flag that remembers, for use when
1714 an ACL cached a sender verify (in case a callout fails). Then if routing set
1715 up a list of hosts or the transport has a host list, and the callout option
1716 is set, and we aren't in a host checking run, do the callout verification,
1717 and set another flag that notes that a callout happened. */
1721 if (routed) *routed = TRUE;
1724 transport_instance * tp;
1725 host_item * host_list = addr->host_list;
1727 /* Make up some data for use in the case where there is no remote
1730 transport_feedback tf = {
1731 NULL, /* interface (=> any) */
1732 US"smtp", /* port */
1733 US"smtp", /* protocol */
1735 US"$smtp_active_hostname", /* helo_data */
1736 FALSE, /* hosts_override */
1737 FALSE, /* hosts_randomize */
1738 FALSE, /* gethostbyname */
1739 TRUE, /* qualify_single */
1740 FALSE /* search_parents */
1743 /* If verification yielded a remote transport, we want to use that
1744 transport's options, so as to mimic what would happen if we were really
1745 sending a message to this address. */
1747 if ((tp = addr->transport) && !tp->info->local)
1749 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1751 /* If the transport has hosts and the router does not, or if the
1752 transport is configured to override the router's hosts, we must build a
1753 host list of the transport's hosts, and find the IP addresses */
1755 if (tf.hosts && (!host_list || tf.hosts_override))
1758 const uschar *save_deliver_domain = deliver_domain;
1759 uschar *save_deliver_localpart = deliver_localpart;
1761 host_list = NULL; /* Ignore the router's hosts */
1763 deliver_domain = addr->domain;
1764 deliver_localpart = addr->local_part;
1765 s = expand_string(tf.hosts);
1766 deliver_domain = save_deliver_domain;
1767 deliver_localpart = save_deliver_localpart;
1771 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1772 "\"%s\" in %s transport for callout: %s", tf.hosts,
1773 tp->name, expand_string_message);
1778 host_item *host, *nexthost;
1779 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1781 /* Just ignore failures to find a host address. If we don't manage
1782 to find any addresses, the callout will defer. Note that more than
1783 one address may be found for a single host, which will result in
1784 additional host items being inserted into the chain. Hence we must
1785 save the next host first. */
1787 flags = HOST_FIND_BY_A;
1788 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1789 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1791 for (host = host_list; host; host = nexthost)
1793 nexthost = host->next;
1794 if (tf.gethostbyname ||
1795 string_is_ip_address(host->name, NULL) != 0)
1796 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1799 dnssec_domains * dnssec_domains = NULL;
1800 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1802 smtp_transport_options_block * ob =
1803 (smtp_transport_options_block *) tp->options_block;
1804 dnssec_domains = &ob->dnssec;
1807 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1808 dnssec_domains, NULL, NULL);
1815 /* Can only do a callout if we have at least one host! If the callout
1816 fails, it will have set ${sender,recipient}_verify_failure. */
1820 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1821 if (host_checking && !host_checking_callout)
1824 debug_printf("... callout omitted by default when host testing\n"
1825 "(Use -bhc if you want the callouts to happen.)\n");
1830 deliver_set_expansions(addr);
1832 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1833 callout_connect, options, se_mailfrom, pm_mailfrom);
1838 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1839 "transport provided a host list\n");
1844 /* Otherwise, any failure is a routing failure */
1846 else *failure_ptr = US"route";
1848 /* A router may return REROUTED if it has set up a child address as a result
1849 of a change of domain name (typically from widening). In this case we always
1850 want to continue to verify the new child. */
1852 if (rc == REROUTED) continue;
1854 /* Handle hard failures */
1861 address_item *p = addr->parent;
1863 respond_printf(f, "%s%s %s", ko_prefix,
1864 full_info ? addr->address : address,
1865 address_test_mode ? "is undeliverable" : "failed to verify");
1866 if (!expn && admin_user)
1868 if (addr->basic_errno > 0)
1869 respond_printf(f, ": %s", strerror(addr->basic_errno));
1871 respond_printf(f, ": %s", addr->message);
1874 /* Show parents iff doing full info */
1876 if (full_info) while (p)
1878 respond_printf(f, "%s\n <-- %s", cr, p->address);
1881 respond_printf(f, "%s\n", cr);
1883 cancel_cutthrough_connection("routing hard fail");
1887 yield = copy_error(vaddr, addr, FAIL);
1895 else if (rc == DEFER)
1900 address_item *p = addr->parent;
1901 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1902 full_info? addr->address : address);
1903 if (!expn && admin_user)
1905 if (addr->basic_errno > 0)
1906 respond_printf(f, ": %s", strerror(addr->basic_errno));
1908 respond_printf(f, ": %s", addr->message);
1909 else if (addr->basic_errno <= 0)
1910 respond_printf(f, ": unknown error");
1913 /* Show parents iff doing full info */
1915 if (full_info) while (p)
1917 respond_printf(f, "%s\n <-- %s", cr, p->address);
1920 respond_printf(f, "%s\n", cr);
1922 cancel_cutthrough_connection("routing soft fail");
1926 yield = copy_error(vaddr, addr, DEFER);
1929 if (yield == OK) yield = DEFER;
1932 /* If we are handling EXPN, we do not want to continue to route beyond
1933 the top level (whose address is in "address"). */
1937 uschar *ok_prefix = US"250-";
1940 if (!addr_local && !addr_remote)
1941 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1943 respond_printf(f, "250 <%s>\r\n", address);
1947 address_item *addr2 = addr_new;
1948 addr_new = addr2->next;
1949 if (!addr_new) ok_prefix = US"250 ";
1950 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1956 /* Successful routing other than EXPN. */
1960 /* Handle successful routing when short info wanted. Otherwise continue for
1961 other (generated) addresses. Short info is the operational case. Full info
1962 can be requested only when debug_selector != 0 and a file is supplied.
1964 There is a conflict between the use of aliasing as an alternate email
1965 address, and as a sort of mailing list. If an alias turns the incoming
1966 address into just one address (e.g. J.Caesar->jc44) you may well want to
1967 carry on verifying the generated address to ensure it is valid when
1968 checking incoming mail. If aliasing generates multiple addresses, you
1969 probably don't want to do this. Exim therefore treats the generation of
1970 just a single new address as a special case, and continues on to verify the
1971 generated address. */
1973 if ( !full_info /* Stop if short info wanted AND */
1974 && ( ( !addr_new /* No new address OR */
1975 || addr_new->next /* More than one new address OR */
1976 || testflag(addr_new, af_pfr) /* New address is pfr */
1979 ( addr_new /* At least one new address AND */
1980 && success_on_redirect /* success_on_redirect is set */
1984 if (f) fprintf(f, "%s %s\n",
1985 address, address_test_mode ? "is deliverable" : "verified");
1987 /* If we have carried on to verify a child address, we want the value
1988 of $address_data to be that of the child */
1990 vaddr->prop.address_data = addr->prop.address_data;
1992 /* If stopped because more than one new address, cannot cutthrough */
1994 if (addr_new && addr_new->next)
1995 cancel_cutthrough_connection("multiple addresses from routing");
2001 } /* Loop for generated addresses */
2003 /* Display the full results of the successful routing, including any generated
2004 addresses. Control gets here only when full_info is set, which requires f not
2005 to be NULL, and this occurs only when a top-level verify is called with the
2006 debugging switch on.
2008 If there are no local and no remote addresses, and there were no pipes, files,
2009 or autoreplies, and there were no errors or deferments, the message is to be
2010 discarded, usually because of the use of :blackhole: in an alias file. */
2012 if (allok && !addr_local && !addr_remote)
2014 fprintf(f, "mail to %s is discarded\n", address);
2018 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2021 address_item *addr = addr_list;
2022 address_item *p = addr->parent;
2023 transport_instance * tp = addr->transport;
2025 addr_list = addr->next;
2027 fprintf(f, "%s", CS addr->address);
2028 #ifdef EXPERIMENTAL_SRS
2029 if(addr->prop.srs_sender)
2030 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2033 /* If the address is a duplicate, show something about it. */
2035 if (!testflag(addr, af_pfr))
2038 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2039 fprintf(f, " [duplicate, would not be delivered]");
2040 else tree_add_duplicate(addr->unique, addr);
2043 /* Now show its parents */
2045 for (p = addr->parent; p; p = p->parent)
2046 fprintf(f, "\n <-- %s", p->address);
2049 /* Show router, and transport */
2051 fprintf(f, "router = %s, transport = %s\n",
2052 addr->router->name, tp ? tp->name : US"unset");
2054 /* Show any hosts that are set up by a router unless the transport
2055 is going to override them; fiddle a bit to get a nice format. */
2057 if (addr->host_list && tp && !tp->overrides_hosts)
2062 for (h = addr->host_list; h; h = h->next)
2063 { /* get max lengths of host names, addrs */
2064 int len = Ustrlen(h->name);
2065 if (len > maxlen) maxlen = len;
2066 len = h->address ? Ustrlen(h->address) : 7;
2067 if (len > maxaddlen) maxaddlen = len;
2069 for (h = addr->host_list; h; h = h->next)
2071 fprintf(f, " host %-*s ", maxlen, h->name);
2074 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2075 else if (tp->info->local)
2076 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2078 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2080 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2081 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2082 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2083 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2089 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2090 the -bv or -bt case). */
2094 tls_modify_variables(&tls_in);
2102 /*************************************************
2103 * Check headers for syntax errors *
2104 *************************************************/
2106 /* This function checks those header lines that contain addresses, and verifies
2107 that all the addresses therein are syntactially correct.
2110 msgptr where to put an error message
2117 verify_check_headers(uschar **msgptr)
2123 for (h = header_list; h != NULL && yield == OK; h = h->next)
2125 if (h->type != htype_from &&
2126 h->type != htype_reply_to &&
2127 h->type != htype_sender &&
2128 h->type != htype_to &&
2129 h->type != htype_cc &&
2130 h->type != htype_bcc)
2133 colon = Ustrchr(h->text, ':');
2135 while (isspace(*s)) s++;
2137 /* Loop for multiple addresses in the header, enabling group syntax. Note
2138 that we have to reset this after the header has been scanned. */
2140 parse_allow_group = TRUE;
2144 uschar *ss = parse_find_address_end(s, FALSE);
2145 uschar *recipient, *errmess;
2146 int terminator = *ss;
2147 int start, end, domain;
2149 /* Temporarily terminate the string at this point, and extract the
2150 operative address within, allowing group syntax. */
2153 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2156 /* Permit an unqualified address only if the message is local, or if the
2157 sending host is configured to be permitted to send them. */
2159 if (recipient != NULL && domain == 0)
2161 if (h->type == htype_from || h->type == htype_sender)
2163 if (!allow_unqualified_sender) recipient = NULL;
2167 if (!allow_unqualified_recipient) recipient = NULL;
2169 if (recipient == NULL) errmess = US"unqualified address not permitted";
2172 /* It's an error if no address could be extracted, except for the special
2173 case of an empty address. */
2175 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2177 uschar *verb = US"is";
2182 /* Arrange not to include any white space at the end in the
2183 error message or the header name. */
2185 while (t > s && isspace(t[-1])) t--;
2186 while (tt > h->text && isspace(tt[-1])) tt--;
2188 /* Add the address that failed to the error message, since in a
2189 header with very many addresses it is sometimes hard to spot
2190 which one is at fault. However, limit the amount of address to
2191 quote - cases have been seen where, for example, a missing double
2192 quote in a humungous To: header creates an "address" that is longer
2193 than string_sprintf can handle. */
2202 /* deconst cast ok as we're passing a non-const to string_printing() */
2203 *msgptr = US string_printing(
2204 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2205 errmess, tt - h->text, h->text, verb, len, s));
2208 break; /* Out of address loop */
2211 /* Advance to the next address */
2213 s = ss + (terminator? 1:0);
2214 while (isspace(*s)) s++;
2215 } /* Next address */
2217 parse_allow_group = FALSE;
2218 parse_found_group = FALSE;
2219 } /* Next header unless yield has been set FALSE */
2225 /*************************************************
2226 * Check header names for 8-bit characters *
2227 *************************************************/
2229 /* This function checks for invalid characters in header names. See
2230 RFC 5322, 2.2. and RFC 6532, 3.
2233 msgptr where to put an error message
2240 verify_check_header_names_ascii(uschar **msgptr)
2245 for (h = header_list; h != NULL; h = h->next)
2247 colon = Ustrchr(h->text, ':');
2248 for(s = h->text; s < colon; s++)
2250 if ((*s < 33) || (*s > 126))
2252 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2253 colon - h->text, h->text);
2261 /*************************************************
2262 * Check for blind recipients *
2263 *************************************************/
2265 /* This function checks that every (envelope) recipient is mentioned in either
2266 the To: or Cc: header lines, thus detecting blind carbon copies.
2268 There are two ways of scanning that could be used: either scan the header lines
2269 and tick off the recipients, or scan the recipients and check the header lines.
2270 The original proposed patch did the former, but I have chosen to do the latter,
2271 because (a) it requires no memory and (b) will use fewer resources when there
2272 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2275 Returns: OK if there are no blind recipients
2276 FAIL if there is at least one blind recipient
2280 verify_check_notblind(void)
2283 for (i = 0; i < recipients_count; i++)
2287 uschar *address = recipients_list[i].address;
2289 for (h = header_list; !found && h != NULL; h = h->next)
2293 if (h->type != htype_to && h->type != htype_cc) continue;
2295 colon = Ustrchr(h->text, ':');
2297 while (isspace(*s)) s++;
2299 /* Loop for multiple addresses in the header, enabling group syntax. Note
2300 that we have to reset this after the header has been scanned. */
2302 parse_allow_group = TRUE;
2306 uschar *ss = parse_find_address_end(s, FALSE);
2307 uschar *recipient,*errmess;
2308 int terminator = *ss;
2309 int start, end, domain;
2311 /* Temporarily terminate the string at this point, and extract the
2312 operative address within, allowing group syntax. */
2315 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2318 /* If we found a valid recipient that has a domain, compare it with the
2319 envelope recipient. Local parts are compared case-sensitively, domains
2320 case-insensitively. By comparing from the start with length "domain", we
2321 include the "@" at the end, which ensures that we are comparing the whole
2322 local part of each address. */
2324 if (recipient != NULL && domain != 0)
2326 found = Ustrncmp(recipient, address, domain) == 0 &&
2327 strcmpic(recipient + domain, address + domain) == 0;
2331 /* Advance to the next address */
2333 s = ss + (terminator? 1:0);
2334 while (isspace(*s)) s++;
2335 } /* Next address */
2337 parse_allow_group = FALSE;
2338 parse_found_group = FALSE;
2339 } /* Next header (if found is false) */
2341 if (!found) return FAIL;
2342 } /* Next recipient */
2349 /*************************************************
2350 * Find if verified sender *
2351 *************************************************/
2353 /* Usually, just a single address is verified as the sender of the message.
2354 However, Exim can be made to verify other addresses as well (often related in
2355 some way), and this is useful in some environments. There may therefore be a
2356 chain of such addresses that have previously been tested. This function finds
2357 whether a given address is on the chain.
2359 Arguments: the address to be verified
2360 Returns: pointer to an address item, or NULL
2364 verify_checked_sender(uschar *sender)
2367 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2368 if (Ustrcmp(sender, addr->address) == 0) break;
2376 /*************************************************
2377 * Get valid header address *
2378 *************************************************/
2380 /* Scan the originator headers of the message, looking for an address that
2381 verifies successfully. RFC 822 says:
2383 o The "Sender" field mailbox should be sent notices of
2384 any problems in transport or delivery of the original
2385 messages. If there is no "Sender" field, then the
2386 "From" field mailbox should be used.
2388 o If the "Reply-To" field exists, then the reply should
2389 go to the addresses indicated in that field and not to
2390 the address(es) indicated in the "From" field.
2392 So we check a Sender field if there is one, else a Reply_to field, else a From
2393 field. As some strange messages may have more than one of these fields,
2394 especially if they are resent- fields, check all of them if there is more than
2398 user_msgptr points to where to put a user error message
2399 log_msgptr points to where to put a log error message
2400 callout timeout for callout check (passed to verify_address())
2401 callout_overall overall callout timeout (ditto)
2402 callout_connect connect callout timeout (ditto)
2403 se_mailfrom mailfrom for verify; NULL => ""
2404 pm_mailfrom sender for pm callout check (passed to verify_address())
2405 options callout options (passed to verify_address())
2406 verrno where to put the address basic_errno
2408 If log_msgptr is set to something without setting user_msgptr, the caller
2409 normally uses log_msgptr for both things.
2411 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2412 FAIL is given if no appropriate headers are found
2416 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2417 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2418 uschar *pm_mailfrom, int options, int *verrno)
2420 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2425 for (i = 0; i < 3 && !done; i++)
2428 for (h = header_list; h != NULL && !done; h = h->next)
2430 int terminator, new_ok;
2431 uschar *s, *ss, *endname;
2433 if (h->type != header_types[i]) continue;
2434 s = endname = Ustrchr(h->text, ':') + 1;
2436 /* Scan the addresses in the header, enabling group syntax. Note that we
2437 have to reset this after the header has been scanned. */
2439 parse_allow_group = TRUE;
2443 address_item *vaddr;
2445 while (isspace(*s) || *s == ',') s++;
2446 if (*s == 0) break; /* End of header */
2448 ss = parse_find_address_end(s, FALSE);
2450 /* The terminator is a comma or end of header, but there may be white
2451 space preceding it (including newline for the last address). Move back
2452 past any white space so we can check against any cached envelope sender
2453 address verifications. */
2455 while (isspace(ss[-1])) ss--;
2459 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2460 (int)(endname - h->text), h->text, s);
2462 /* See if we have already verified this address as an envelope sender,
2463 and if so, use the previous answer. */
2465 vaddr = verify_checked_sender(s);
2467 if (vaddr != NULL && /* Previously checked */
2468 (callout <= 0 || /* No callout needed; OR */
2469 vaddr->special_action > 256)) /* Callout was done */
2471 new_ok = vaddr->special_action & 255;
2472 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2473 *ss = terminator; /* Restore shortened string */
2476 /* Otherwise we run the verification now. We must restore the shortened
2477 string before running the verification, so the headers are correct, in
2478 case there is any rewriting. */
2482 int start, end, domain;
2483 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2488 /* If we found an empty address, just carry on with the next one, but
2489 kill the message. */
2491 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2498 /* If verification failed because of a syntax error, fail this
2499 function, and ensure that the failing address gets added to the error
2502 if (address == NULL)
2505 while (ss > s && isspace(ss[-1])) ss--;
2506 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2507 "scanning for sender: %s in \"%.*s\"",
2508 endname - h->text, h->text, *log_msgptr, ss - s, s);
2514 /* Else go ahead with the sender verification. But it isn't *the*
2515 sender of the message, so set vopt_fake_sender to stop sender_address
2516 being replaced after rewriting or qualification. */
2520 vaddr = deliver_make_addr(address, FALSE);
2521 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2522 callout, callout_overall, callout_connect, se_mailfrom,
2527 /* We now have the result, either newly found, or cached. If we are
2528 giving out error details, set a specific user error. This means that the
2529 last of these will be returned to the user if all three fail. We do not
2530 set a log message - the generic one below will be used. */
2534 *verrno = vaddr->basic_errno;
2535 if (smtp_return_error_details)
2537 *user_msgptr = string_sprintf("Rejected after DATA: "
2538 "could not verify \"%.*s\" header address\n%s: %s",
2539 endname - h->text, h->text, vaddr->address, vaddr->message);
2543 /* Success or defer */
2552 if (new_ok == DEFER) yield = DEFER;
2554 /* Move on to any more addresses in the header */
2557 } /* Next address */
2559 parse_allow_group = FALSE;
2560 parse_found_group = FALSE;
2561 } /* Next header, unless done */
2562 } /* Next header type unless done */
2564 if (yield == FAIL && *log_msgptr == NULL)
2565 *log_msgptr = US"there is no valid sender in any header line";
2567 if (yield == DEFER && *log_msgptr == NULL)
2568 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2576 /*************************************************
2577 * Get RFC 1413 identification *
2578 *************************************************/
2580 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2581 the timeout is set to zero, then the query is not done. There may also be lists
2582 of hosts and nets which are exempt. To guard against malefactors sending
2583 non-printing characters which could, for example, disrupt a message's headers,
2584 make sure the string consists of printing characters only.
2587 port the port to connect to; usually this is IDENT_PORT (113), but when
2588 running in the test harness with -bh a different value is used.
2592 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2596 verify_get_ident(int port)
2598 int sock, host_af, qlen;
2599 int received_sender_port, received_interface_port, n;
2601 uschar buffer[2048];
2603 /* Default is no ident. Check whether we want to do an ident check for this
2606 sender_ident = NULL;
2607 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2610 DEBUG(D_ident) debug_printf("doing ident callback\n");
2612 /* Set up a connection to the ident port of the remote host. Bind the local end
2613 to the incoming interface address. If the sender host address is an IPv6
2614 address, the incoming interface address will also be IPv6. */
2616 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2617 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2619 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2621 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2626 if (ip_connect(sock, host_af, sender_host_address, port,
2627 rfc1413_query_timeout, TRUE) < 0)
2629 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2630 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2631 sender_host_address);
2633 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2634 sender_host_address, strerror(errno));
2638 /* Construct and send the query. */
2640 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2641 qlen = Ustrlen(buffer);
2642 if (send(sock, buffer, qlen, 0) < 0)
2644 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2648 /* Read a response line. We put it into the rest of the buffer, using several
2649 recv() calls if necessary. */
2657 int size = sizeof(buffer) - (p - buffer);
2659 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2660 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2661 if (count <= 0) goto END_OFF; /* Read error or EOF */
2663 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2664 generous, and accept a plain \n terminator as well. The only illegal
2667 for (pp = p; pp < p + count; pp++)
2669 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2672 if (pp[-1] == '\r') pp--;
2674 goto GOT_DATA; /* Break out of both loops */
2678 /* Reached the end of the data without finding \n. Let the loop continue to
2679 read some more, if there is room. */
2686 /* We have received a line of data. Check it carefully. It must start with the
2687 same two port numbers that we sent, followed by data as defined by the RFC. For
2690 12345 , 25 : USERID : UNIX :root
2692 However, the amount of white space may be different to what we sent. In the
2693 "osname" field there may be several sub-fields, comma separated. The data we
2694 actually want to save follows the third colon. Some systems put leading spaces
2695 in it - we discard those. */
2697 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2698 &received_interface_port, &n) != 2 ||
2699 received_sender_port != sender_host_port ||
2700 received_interface_port != interface_port)
2703 p = buffer + qlen + n;
2704 while(isspace(*p)) p++;
2705 if (*p++ != ':') goto END_OFF;
2706 while(isspace(*p)) p++;
2707 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2709 while(isspace(*p)) p++;
2710 if (*p++ != ':') goto END_OFF;
2711 while (*p != 0 && *p != ':') p++;
2712 if (*p++ == 0) goto END_OFF;
2713 while(isspace(*p)) p++;
2714 if (*p == 0) goto END_OFF;
2716 /* The rest of the line is the data we want. We turn it into printing
2717 characters when we save it, so that it cannot mess up the format of any logging
2718 or Received: lines into which it gets inserted. We keep a maximum of 127
2719 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2721 sender_ident = US string_printing(string_copyn(p, 127));
2722 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2732 /*************************************************
2733 * Match host to a single host-list item *
2734 *************************************************/
2736 /* This function compares a host (name or address) against a single item
2737 from a host list. The host name gets looked up if it is needed and is not
2738 already known. The function is called from verify_check_this_host() via
2739 match_check_list(), which is why most of its arguments are in a single block.
2742 arg the argument block (see below)
2743 ss the host-list item
2744 valueptr where to pass back looked up data, or NULL
2745 error for error message when returning ERROR
2748 host_name (a) the host name, or
2749 (b) NULL, implying use sender_host_name and
2750 sender_host_aliases, looking them up if required, or
2751 (c) the empty string, meaning that only IP address matches
2753 host_address the host address
2754 host_ipv4 the IPv4 address taken from an IPv6 one
2758 DEFER lookup deferred
2759 ERROR (a) failed to find the host name or IP address, or
2760 (b) unknown lookup type specified, or
2761 (c) host name encountered when only IP addresses are
2766 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2768 check_host_block *cb = (check_host_block *)arg;
2771 BOOL iplookup = FALSE;
2772 BOOL isquery = FALSE;
2773 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2778 /* Optimize for the special case when the pattern is "*". */
2780 if (*ss == '*' && ss[1] == 0) return OK;
2782 /* If the pattern is empty, it matches only in the case when there is no host -
2783 this can occur in ACL checking for SMTP input using the -bs option. In this
2784 situation, the host address is the empty string. */
2786 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2787 if (*ss == 0) return FAIL;
2789 /* If the pattern is precisely "@" then match against the primary host name,
2790 provided that host name matching is permitted; if it's "@[]" match against the
2791 local host's IP addresses. */
2797 if (isiponly) return ERROR;
2798 ss = primary_hostname;
2800 else if (Ustrcmp(ss, "@[]") == 0)
2802 ip_address_item *ip;
2803 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2804 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2809 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2810 a (possibly masked) comparison with the current IP address. */
2812 if (string_is_ip_address(ss, &maskoffset) != 0)
2813 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2815 /* The pattern is not an IP address. A common error that people make is to omit
2816 one component of an IPv4 address, either by accident, or believing that, for
2817 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,
2818 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2819 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2820 ancient specification.) To aid in debugging these cases, we give a specific
2821 error if the pattern contains only digits and dots or contains a slash preceded
2822 only by digits and dots (a slash at the start indicates a file name and of
2823 course slashes may be present in lookups, but not preceded only by digits and
2826 for (t = ss; isdigit(*t) || *t == '.'; t++);
2827 if (*t == 0 || (*t == '/' && t != ss))
2829 *error = US"malformed IPv4 address or address mask";
2833 /* See if there is a semicolon in the pattern */
2835 semicolon = Ustrchr(ss, ';');
2837 /* If we are doing an IP address only match, then all lookups must be IP
2838 address lookups, even if there is no "net-". */
2842 iplookup = semicolon != NULL;
2845 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2846 a lookup on a masked IP network, in textual form. We obey this code even if we
2847 have already set iplookup, so as to skip over the "net-" prefix and to set the
2848 mask length. The net- stuff really only applies to single-key lookups where the
2849 key is implicit. For query-style lookups the key is specified in the query.
2850 From release 4.30, the use of net- for query style is no longer needed, but we
2851 retain it for backward compatibility. */
2853 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2856 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2857 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2858 iplookup = (*t++ == '-');
2862 /* Do the IP address lookup if that is indeed what we have */
2870 uschar *filename, *key, *result;
2873 /* Find the search type */
2875 search_type = search_findtype(t, semicolon - t);
2877 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2878 search_error_message);
2880 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2881 is no file name, and the "key" is just the query. For query-style with a file
2882 name, we have to fish the file off the start of the query. For a single-key
2883 lookup, the key is the current IP address, masked appropriately, and
2884 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2885 dot separators instead of colons, except when the lookup type is "iplsearch".
2888 if (mac_islookup(search_type, lookup_absfilequery))
2890 filename = semicolon + 1;
2892 while (*key != 0 && !isspace(*key)) key++;
2893 filename = string_copyn(filename, key - filename);
2894 while (isspace(*key)) key++;
2896 else if (mac_islookup(search_type, lookup_querystyle))
2899 key = semicolon + 1;
2901 else /* Single-key style */
2903 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2905 insize = host_aton(cb->host_address, incoming);
2906 host_mask(insize, incoming, mlen);
2907 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2909 filename = semicolon + 1;
2912 /* Now do the actual lookup; note that there is no search_close() because
2913 of the caching arrangements. */
2915 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2916 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2918 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2919 if (valueptr != NULL) *valueptr = result;
2920 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2923 /* The pattern is not an IP address or network reference of any kind. That is,
2924 it is a host name pattern. If this is an IP only match, there's an error in the
2929 *error = US"cannot match host name in match_ip list";
2933 /* Check the characters of the pattern to see if they comprise only letters,
2934 digits, full stops, and hyphens (the constituents of domain names). Allow
2935 underscores, as they are all too commonly found. Sigh. Also, if
2936 allow_utf8_domains is set, allow top-bit characters. */
2938 for (t = ss; *t != 0; t++)
2939 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2940 (!allow_utf8_domains || *t < 128)) break;
2942 /* If the pattern is a complete domain name, with no fancy characters, look up
2943 its IP address and match against that. Note that a multi-homed host will add
2944 items to the chain. */
2955 /* Using byname rather than bydns here means we cannot determine dnssec
2956 status. On the other hand it is unclear how that could be either
2957 propagated up or enforced. */
2959 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2960 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2963 for (hh = &h; hh != NULL; hh = hh->next)
2965 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2969 if (rc == HOST_FIND_AGAIN) return DEFER;
2970 *error = string_sprintf("failed to find IP address for %s", ss);
2974 /* Almost all subsequent comparisons require the host name, and can be done
2975 using the general string matching function. When this function is called for
2976 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2977 must use sender_host_name and its aliases, looking them up if necessary. */
2979 if (cb->host_name != NULL) /* Explicit host name given */
2980 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2983 /* Host name not given; in principle we need the sender host name and its
2984 aliases. However, for query-style lookups, we do not need the name if the
2985 query does not contain $sender_host_name. From release 4.23, a reference to
2986 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2989 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2991 const uschar *affix;
2992 int partial, affixlen, starflags, id;
2995 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2998 if (id < 0) /* Unknown lookup type */
3000 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3001 search_error_message, ss);
3004 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3009 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3012 case DEFER: return DEFER;
3013 default: return FAIL;
3017 /* Not a query-style lookup; must ensure the host name is present, and then we
3018 do a check on the name and all its aliases. */
3020 if (sender_host_name == NULL)
3022 HDEBUG(D_host_lookup)
3023 debug_printf("sender host name required, to match against %s\n", ss);
3024 if (host_lookup_failed || host_name_lookup() != OK)
3026 *error = string_sprintf("failed to find host name for %s",
3027 sender_host_address);;
3030 host_build_sender_fullhost();
3033 /* Match on the sender host name, using the general matching function */
3035 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3039 case DEFER: return DEFER;
3042 /* If there are aliases, try matching on them. */
3044 aliases = sender_host_aliases;
3045 while (*aliases != NULL)
3047 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3050 case DEFER: return DEFER;
3059 /*************************************************
3060 * Check a specific host matches a host list *
3061 *************************************************/
3063 /* This function is passed a host list containing items in a number of
3064 different formats and the identity of a host. Its job is to determine whether
3065 the given host is in the set of hosts defined by the list. The host name is
3066 passed as a pointer so that it can be looked up if needed and not already
3067 known. This is commonly the case when called from verify_check_host() to check
3068 an incoming connection. When called from elsewhere the host name should usually
3071 This function is now just a front end to match_check_list(), which runs common
3072 code for scanning a list. We pass it the check_host() function to perform a
3076 listptr pointer to the host list
3077 cache_bits pointer to cache for named lists, or NULL
3078 host_name the host name or NULL, implying use sender_host_name and
3079 sender_host_aliases, looking them up if required
3080 host_address the IP address
3081 valueptr if not NULL, data from a lookup is passed back here
3083 Returns: OK if the host is in the defined set
3084 FAIL if the host is not in the defined set,
3085 DEFER if a data lookup deferred (not a host lookup)
3087 If the host name was needed in order to make a comparison, and could not be
3088 determined from the IP address, the result is FAIL unless the item
3089 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3092 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3093 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3096 unsigned int *local_cache_bits = cache_bits;
3097 const uschar *save_host_address = deliver_host_address;
3098 check_host_block cb;
3099 cb.host_name = host_name;
3100 cb.host_address = host_address;
3102 if (valueptr != NULL) *valueptr = NULL;
3104 /* If the host address starts off ::ffff: it is an IPv6 address in
3105 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3108 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3109 host_address + 7 : host_address;
3111 /* During the running of the check, put the IP address into $host_address. In
3112 the case of calls from the smtp transport, it will already be there. However,
3113 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3114 the safe side, any existing setting is preserved, though as I write this
3115 (November 2004) I can't see any cases where it is actually needed. */
3117 deliver_host_address = host_address;
3118 rc = match_check_list(
3119 listptr, /* the list */
3120 0, /* separator character */
3121 &hostlist_anchor, /* anchor pointer */
3122 &local_cache_bits, /* cache pointer */
3123 check_host, /* function for testing */
3124 &cb, /* argument for function */
3125 MCL_HOST, /* type of check */
3126 (host_address == sender_host_address)?
3127 US"host" : host_address, /* text for debugging */
3128 valueptr); /* where to pass back data */
3129 deliver_host_address = save_host_address;
3136 /*************************************************
3137 * Check the given host item matches a list *
3138 *************************************************/
3140 verify_check_given_host(uschar **listptr, host_item *host)
3142 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3145 /*************************************************
3146 * Check the remote host matches a list *
3147 *************************************************/
3149 /* This is a front end to verify_check_this_host(), created because checking
3150 the remote host is a common occurrence. With luck, a good compiler will spot
3151 the tail recursion and optimize it. If there's no host address, this is
3152 command-line SMTP input - check against an empty string for the address.
3155 listptr pointer to the host list
3157 Returns: the yield of verify_check_this_host(),
3158 i.e. OK, FAIL, or DEFER
3162 verify_check_host(uschar **listptr)
3164 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3165 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3172 /*************************************************
3173 * Invert an IP address *
3174 *************************************************/
3176 /* Originally just used for DNS xBL lists, now also used for the
3177 reverse_ip expansion operator.
3180 buffer where to put the answer
3181 address the address to invert
3185 invert_address(uschar *buffer, uschar *address)
3188 uschar *bptr = buffer;
3190 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3191 to the IPv4 part only. */
3193 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3195 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3198 if (host_aton(address, bin) == 1)
3202 for (i = 0; i < 4; i++)
3204 sprintf(CS bptr, "%d.", x & 255);
3205 while (*bptr) bptr++;
3210 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3211 in any DNS black lists, and the format in which they will be looked up is
3212 unknown. This is just a guess. */
3218 for (j = 3; j >= 0; j--)
3221 for (i = 0; i < 8; i++)
3223 sprintf(CS bptr, "%x.", x & 15);
3224 while (*bptr) bptr++;
3231 /* Remove trailing period -- this is needed so that both arbitrary
3232 dnsbl keydomains and inverted addresses may be combined with the
3233 same format string, "%s.%s" */
3240 /*************************************************
3241 * Perform a single dnsbl lookup *
3242 *************************************************/
3244 /* This function is called from verify_check_dnsbl() below. It is also called
3245 recursively from within itself when domain and domain_txt are different
3246 pointers, in order to get the TXT record from the alternate domain.
3249 domain the outer dnsbl domain
3250 domain_txt alternate domain to lookup TXT record on success; when the
3251 same domain is to be used, domain_txt == domain (that is,
3252 the pointers must be identical, not just the text)
3253 keydomain the current keydomain (for debug message)
3254 prepend subdomain to lookup (like keydomain, but
3255 reversed if IP address)
3256 iplist the list of matching IP addresses, or NULL for "any"
3257 bitmask true if bitmask matching is wanted
3258 match_type condition for 'succeed' result
3259 0 => Any RR in iplist (=)
3260 1 => No RR in iplist (!=)
3261 2 => All RRs in iplist (==)
3262 3 => Some RRs not in iplist (!==)
3263 the two bits are defined as MT_NOT and MT_ALL
3264 defer_return what to return for a defer
3266 Returns: OK if lookup succeeded
3271 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3272 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3278 dnsbl_cache_block *cb;
3279 int old_pool = store_pool;
3280 uschar query[256]; /* DNS domain max length */
3282 /* Construct the specific query domainname */
3284 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3286 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3287 "(ignored): %s...", query);
3291 /* Look for this query in the cache. */
3293 if ( (t = tree_search(dnsbl_cache, query))
3294 && (cb = t->data.ptr)->expiry > time(NULL)
3297 /* Previous lookup was cached */
3300 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3303 /* If not cached from a previous lookup, we must do a DNS lookup, and
3304 cache the result in permanent memory. */
3310 store_pool = POOL_PERM;
3314 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3318 { /* Set up a tree entry to cache the lookup */
3319 t = store_get(sizeof(tree_node) + Ustrlen(query));
3320 Ustrcpy(t->name, query);
3321 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3322 (void)tree_insertnode(&dnsbl_cache, t);
3325 /* Do the DNS lookup . */
3327 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3328 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3329 cb->text_set = FALSE;
3333 /* If the lookup succeeded, cache the RHS address. The code allows for
3334 more than one address - this was for complete generality and the possible
3335 use of A6 records. However, A6 records have been reduced to experimental
3336 status (August 2001) and may die out. So they may never get used at all,
3337 let alone in dnsbl records. However, leave the code here, just in case.
3339 Quite apart from one A6 RR generating multiple addresses, there are DNS
3340 lists that return more than one A record, so we must handle multiple
3341 addresses generated in that way as well.
3343 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3344 or some suitably far-future time if none were found. */
3346 if (cb->rc == DNS_SUCCEED)
3349 dns_address **addrp = &(cb->rhs);
3350 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3352 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3354 if (rr->type == T_A)
3356 dns_address *da = dns_address_from_rr(&dnsa, rr);
3360 while (da->next != NULL) da = da->next;
3361 addrp = &(da->next);
3362 if (ttl > rr->ttl) ttl = rr->ttl;
3367 /* If we didn't find any A records, change the return code. This can
3368 happen when there is a CNAME record but there are no A records for what
3371 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3374 cb->expiry = time(NULL)+ttl;
3375 store_pool = old_pool;
3378 /* We now have the result of the DNS lookup, either newly done, or cached
3379 from a previous call. If the lookup succeeded, check against the address
3380 list if there is one. This may be a positive equality list (introduced by
3381 "="), a negative equality list (introduced by "!="), a positive bitmask
3382 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3384 if (cb->rc == DNS_SUCCEED)
3386 dns_address *da = NULL;
3387 uschar *addlist = cb->rhs->address;
3389 /* For A and AAAA records, there may be multiple addresses from multiple
3390 records. For A6 records (currently not expected to be used) there may be
3391 multiple addresses from a single record. */
3393 for (da = cb->rhs->next; da != NULL; da = da->next)
3394 addlist = string_sprintf("%s, %s", addlist, da->address);
3396 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3399 /* Address list check; this can be either for equality, or via a bitmask.
3400 In the latter case, all the bits must match. */
3404 for (da = cb->rhs; da != NULL; da = da->next)
3408 const uschar *ptr = iplist;
3411 /* Handle exact matching */
3415 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3417 if (Ustrcmp(CS da->address, ip) == 0) break;
3421 /* Handle bitmask matching */
3428 /* At present, all known DNS blocking lists use A records, with
3429 IPv4 addresses on the RHS encoding the information they return. I
3430 wonder if this will linger on as the last vestige of IPv4 when IPv6
3431 is ubiquitous? Anyway, for now we use paranoia code to completely
3432 ignore IPv6 addresses. The default mask is 0, which always matches.
3433 We change this only for IPv4 addresses in the list. */
3435 if (host_aton(da->address, address) == 1) mask = address[0];
3437 /* Scan the returned addresses, skipping any that are IPv6 */
3439 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3441 if (host_aton(ip, address) != 1) continue;
3442 if ((address[0] & mask) == address[0]) break;
3448 (a) An IP address in an any ('=') list matched, or
3449 (b) No IP address in an all ('==') list matched
3451 then we're done searching. */
3453 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3456 /* If da == NULL, either
3458 (a) No IP address in an any ('=') list matched, or
3459 (b) An IP address in an all ('==') list didn't match
3461 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3464 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3472 res = US"was no match";
3475 res = US"was an exclude match";
3478 res = US"was an IP address that did not match";
3481 res = US"were no IP addresses that did not match";
3484 debug_printf("=> but we are not accepting this block class because\n");
3485 debug_printf("=> there %s for %s%c%s\n",
3487 ((match_type & MT_ALL) == 0)? "" : "=",
3488 bitmask? '&' : '=', iplist);
3494 /* Either there was no IP list, or the record matched, implying that the
3495 domain is on the list. We now want to find a corresponding TXT record. If an
3496 alternate domain is specified for the TXT record, call this function
3497 recursively to look that up; this has the side effect of re-checking that
3498 there is indeed an A record at the alternate domain. */
3500 if (domain_txt != domain)
3501 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3502 FALSE, match_type, defer_return);
3504 /* If there is no alternate domain, look up a TXT record in the main domain
3505 if it has not previously been cached. */
3509 cb->text_set = TRUE;
3510 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3513 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3515 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3516 if (rr->type == T_TXT) break;
3519 int len = (rr->data)[0];
3520 if (len > 511) len = 127;
3521 store_pool = POOL_PERM;
3522 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3523 store_pool = old_pool;
3528 dnslist_value = addlist;
3529 dnslist_text = cb->text;
3533 /* There was a problem with the DNS lookup */
3535 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3537 log_write(L_dnslist_defer, LOG_MAIN,
3538 "DNS list lookup defer (probably timeout) for %s: %s", query,
3539 (defer_return == OK)? US"assumed in list" :
3540 (defer_return == FAIL)? US"assumed not in list" :
3541 US"returned DEFER");
3542 return defer_return;
3545 /* No entry was found in the DNS; continue for next domain */
3549 debug_printf("DNS lookup for %s failed\n", query);
3550 debug_printf("=> that means %s is not listed at %s\n",
3560 /*************************************************
3561 * Check host against DNS black lists *
3562 *************************************************/
3564 /* This function runs checks against a list of DNS black lists, until one
3565 matches. Each item on the list can be of the form
3567 domain=ip-address/key
3569 The domain is the right-most domain that is used for the query, for example,
3570 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3571 if the DNS lookup returns a matching IP address. Several addresses may be
3572 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3574 If no key is given, what is looked up in the domain is the inverted IP address
3575 of the current client host. If a key is given, it is used to construct the
3576 domain for the lookup. For example:
3578 dsn.rfc-ignorant.org/$sender_address_domain
3580 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3581 then we check for a TXT record for an error message, and if found, save its
3582 value in $dnslist_text. We also cache everything in a tree, to optimize
3585 The TXT record is normally looked up in the same domain as the A record, but
3586 when many lists are combined in a single DNS domain, this will not be a very
3587 specific message. It is possible to specify a different domain for looking up
3588 TXT records; this is given before the main domain, comma-separated. For
3591 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3592 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3594 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3596 Note: an address for testing RBL is 192.203.178.39
3597 Note: an address for testing DUL is 192.203.178.4
3598 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3602 listptr the domain/address/data list
3603 log_msgptr log message on error
3605 Returns: OK successful lookup (i.e. the address is on the list), or
3606 lookup deferred after +include_unknown
3607 FAIL name not found, or no data found for the given type, or
3608 lookup deferred after +exclude_unknown (default)
3609 DEFER lookup failure, if +defer_unknown was set
3613 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3616 int defer_return = FAIL;
3617 const uschar *list = *listptr;
3620 uschar buffer[1024];
3621 uschar revadd[128]; /* Long enough for IPv6 address */
3623 /* Indicate that the inverted IP address is not yet set up */
3627 /* In case this is the first time the DNS resolver is being used. */
3629 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3631 /* Loop through all the domains supplied, until something matches */
3633 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3636 BOOL bitmask = FALSE;
3643 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3645 /* Deal with special values that change the behaviour on defer */
3647 if (domain[0] == '+')
3649 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3650 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3651 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3653 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3658 /* See if there's explicit data to be looked up */
3660 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3662 /* See if there's a list of addresses supplied after the domain name. This is
3663 introduced by an = or a & character; if preceded by = we require all matches
3664 and if preceded by ! we invert the result. */
3666 if (!(iplist = Ustrchr(domain, '=')))
3669 iplist = Ustrchr(domain, '&');
3672 if (iplist) /* Found either = or & */
3674 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3676 match_type |= MT_NOT;
3680 *iplist++ = 0; /* Terminate domain, move on */
3682 /* If we found = (bitmask == FALSE), check for == or =& */
3684 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3686 bitmask = *iplist++ == '&';
3687 match_type |= MT_ALL;
3692 /* If there is a comma in the domain, it indicates that a second domain for
3693 looking up TXT records is provided, before the main domain. Otherwise we must
3694 set domain_txt == domain. */
3696 domain_txt = domain;
3697 comma = Ustrchr(domain, ',');
3704 /* Check that what we have left is a sensible domain name. There is no reason
3705 why these domains should in fact use the same syntax as hosts and email
3706 domains, but in practice they seem to. However, there is little point in
3707 actually causing an error here, because that would no doubt hold up incoming
3708 mail. Instead, I'll just log it. */
3710 for (s = domain; *s != 0; s++)
3712 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3714 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3715 "strange characters - is this right?", domain);
3720 /* Check the alternate domain if present */
3722 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3724 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3726 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3727 "strange characters - is this right?", domain_txt);
3732 /* If there is no key string, construct the query by adding the domain name
3733 onto the inverted host address, and perform a single DNS lookup. */
3737 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3739 *log_msgptr = string_sprintf
3740 ("cannot test auto-keyed dnslists condition in %s ACL",
3741 acl_wherenames[where]);
3744 if (sender_host_address == NULL) return FAIL; /* can never match */
3745 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3746 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3747 iplist, bitmask, match_type, defer_return);
3750 dnslist_domain = string_copy(domain_txt);
3751 dnslist_matched = string_copy(sender_host_address);
3752 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3753 sender_host_address, dnslist_domain);
3755 if (rc != FAIL) return rc; /* OK or DEFER */
3758 /* If there is a key string, it can be a list of domains or IP addresses to
3759 be concatenated with the main domain. */
3766 uschar keybuffer[256];
3767 uschar keyrevadd[128];
3769 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3770 sizeof(keybuffer))) != NULL)
3772 uschar *prepend = keydomain;
3774 if (string_is_ip_address(keydomain, NULL) != 0)
3776 invert_address(keyrevadd, keydomain);
3777 prepend = keyrevadd;
3780 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3781 bitmask, match_type, defer_return);
3785 dnslist_domain = string_copy(domain_txt);
3786 dnslist_matched = string_copy(keydomain);
3787 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3788 keydomain, dnslist_domain);
3792 /* If the lookup deferred, remember this fact. We keep trying the rest
3793 of the list to see if we get a useful result, and if we don't, we return
3794 DEFER at the end. */
3796 if (rc == DEFER) defer = TRUE;
3797 } /* continue with next keystring domain/address */
3799 if (defer) return DEFER;
3801 } /* continue with next dnsdb outer domain */
3808 /* End of verify.c */