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.
783 Avoid using a SIZE option on the MAIL for all randon-rcpt checks.
786 sx.avoid_option = OPTION_SIZE;
788 /* Remember when we last did a random test */
789 new_domain_record.random_stamp = time(NULL);
791 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
792 switch(addr->transport_return)
795 new_domain_record.random_result = ccache_accept;
796 yield = OK; /* Only usable result we can return */
799 case FAIL: /* the preferred result */
800 new_domain_record.random_result = ccache_reject;
803 /* Between each check, issue RSET, because some servers accept only
804 one recipient after MAIL FROM:<>.
805 XXX We don't care about that for postmaster_full. Should we? */
808 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
809 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
814 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
815 random_local_part = NULL;
817 tls_close(FALSE, TRUE);
819 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
820 (void)close(sx.inblock.sock);
821 sx.inblock.sock = sx.outblock.sock = -1;
822 #ifndef DISABLE_EVENT
823 (void) event_raise(addr->transport->event_action,
824 US"tcp:close", NULL);
826 addr->address = main_address;
827 addr->transport_return = PENDING_DEFER;
828 sx.first_addr = sx.sync_addr = addr;
831 sx.completed_addr = FALSE;
832 goto tls_retry_connection;
835 /* Re-setup for main verify, or for the error message when failing */
836 addr->address = main_address;
837 addr->transport_return = PENDING_DEFER;
838 sx.first_addr = sx.sync_addr = addr;
841 sx.completed_addr = FALSE;
846 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
847 for sndr-verify never use it. */
851 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
852 sx.avoid_option = OPTION_SIZE;
855 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
857 case 0: switch(addr->transport_return) /* ok so far */
859 case PENDING_OK: done = TRUE;
860 new_address_record.result = ccache_accept;
862 case FAIL: done = TRUE;
864 *failure_ptr = US"recipient";
865 new_address_record.result = ccache_reject;
871 case -1: /* MAIL response error */
872 *failure_ptr = US"mail";
873 if (errno == 0 && sx.buffer[0] == '5')
875 setflag(addr, af_verify_nsfail);
876 if (from_address[0] == 0)
877 new_domain_record.result = ccache_reject_mfnull;
880 /* non-MAIL read i/o error */
881 /* non-MAIL response timeout */
882 /* internal error; channel still usable */
883 default: break; /* transmit failed */
887 addr->auth_sndr = client_authenticated_sender;
889 deliver_host = deliver_host_address = NULL;
890 deliver_domain = save_deliver_domain;
892 /* Do postmaster check if requested; if a full check is required, we
893 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
895 if (done && pm_mailfrom)
897 /* Could possibly shift before main verify, just above, and be ok
898 for cutthrough. But no way to handle a subsequent rcpt, so just
900 cancel_cutthrough_connection("postmaster verify");
901 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
903 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
904 && smtp_read_response(&sx.inblock, sx.buffer,
905 sizeof(sx.buffer), '2', callout);
909 uschar * main_address = addr->address;
911 /*XXX oops, affixes */
912 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
913 addr->transport_return = PENDING_DEFER;
915 sx.from_addr = pm_mailfrom;
916 sx.first_addr = sx.sync_addr = addr;
919 sx.completed_addr = FALSE;
920 sx.avoid_option = OPTION_SIZE;
922 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
923 && addr->transport_return == PENDING_OK
927 done = (options & vopt_callout_fullpm) != 0
928 && smtp_write_command(&sx.outblock, FALSE,
929 "RCPT TO:<postmaster>\r\n") >= 0
930 && smtp_read_response(&sx.inblock, sx.buffer,
931 sizeof(sx.buffer), '2', callout);
933 /* Sort out the cache record */
935 new_domain_record.postmaster_stamp = time(NULL);
938 new_domain_record.postmaster_result = ccache_accept;
939 else if (errno == 0 && sx.buffer[0] == '5')
941 *failure_ptr = US"postmaster";
942 setflag(addr, af_verify_pmfail);
943 new_domain_record.postmaster_result = ccache_reject;
946 addr->address = main_address;
949 /* For any failure of the main check, other than a negative response, we just
950 close the connection and carry on. We can identify a negative response by the
951 fact that errno is zero. For I/O errors it will be non-zero
953 Set up different error texts for logging and for sending back to the caller
954 as an SMTP response. Log in all cases, using a one-line format. For sender
955 callouts, give a full response to the caller, but for recipient callouts,
956 don't give the IP address because this may be an internal host whose identity
957 is not to be widely broadcast. */
963 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
964 sx.send_quit = FALSE;
970 extern int acl_where; /* src/acl.c */
972 addr->message = string_sprintf(
973 "response to \"EHLO\" did not include SMTPUTF8");
974 addr->user_message = acl_where == ACL_WHERE_RCPT
975 ? US"533 no support for internationalised mailbox name"
976 : US"550 mailbox unavailable";
983 sx.send_quit = FALSE;
987 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
989 /*XXX test here is ugly; seem to have a split of responsibility for
990 building this message. Need to reationalise. Where is it done
991 before here, and when not?
992 Not == 5xx resp to MAIL on main-verify
994 if (!addr->message) addr->message =
995 string_sprintf("response to \"%s\" was: %s",
996 big_buffer, string_printing(sx.buffer));
998 addr->user_message = options & vopt_is_recipient
999 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
1000 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1001 host->address, big_buffer, sx.buffer);
1003 /* Hard rejection ends the process */
1005 if (sx.buffer[0] == '5') /* Address rejected */
1013 /* End the SMTP conversation and close the connection. */
1015 /* Cutthrough - on a successful connect and recipient-verify with
1016 use-sender and we are 1st rcpt and have no cutthrough conn so far
1017 here is where we want to leave the conn open */
1018 if ( cutthrough.delivery
1022 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1023 == vopt_callout_recipsender
1024 && !random_local_part
1026 && cutthrough.fd < 0
1030 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for cutthrough delivery\n");
1032 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1033 cutthrough.nrcpt = 1;
1034 cutthrough.interface = interface;
1035 cutthrough.host = *host;
1036 cutthrough.addr = *addr; /* Save the address_item for later logging */
1037 cutthrough.addr.next = NULL;
1038 cutthrough.addr.host_used = &cutthrough.host;
1040 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1042 ctblock.buffer = ctbuffer;
1043 ctblock.buffersize = sizeof(ctbuffer);
1044 ctblock.ptr = ctbuffer;
1045 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1046 ctblock.sock = cutthrough.fd;
1050 /* Ensure no cutthrough on multiple address verifies */
1051 if (options & vopt_callout_recipsender)
1052 cancel_cutthrough_connection("not usable for cutthrough");
1055 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1057 /* Wait a short time for response, and discard it */
1058 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1062 if (sx.inblock.sock >= 0)
1065 tls_close(FALSE, TRUE);
1067 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1068 (void)close(sx.inblock.sock);
1069 sx.inblock.sock = sx.outblock.sock = -1;
1070 #ifndef DISABLE_EVENT
1071 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1076 if (!done || yield != OK)
1077 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1079 } /* Loop through all hosts, while !done */
1082 /* If we get here with done == TRUE, a successful callout happened, and yield
1083 will be set OK or FAIL according to the response to the RCPT command.
1084 Otherwise, we looped through the hosts but couldn't complete the business.
1085 However, there may be domain-specific information to cache in both cases. */
1087 if (!(options & vopt_callout_no_cache))
1088 cache_callout_write(&new_domain_record, addr->domain,
1089 done, &new_address_record, address_key);
1091 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1092 temporary error. If there was only one host, and a response was received, leave
1093 it alone if supplying details. Otherwise, give a generic response. */
1097 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1098 options & vopt_is_recipient ? "recipient" : "sender");
1101 addr->message = host_list->next || !addr->message
1102 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1104 addr->user_message = smtp_return_error_details
1105 ? string_sprintf("%s for <%s>.\n"
1106 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1107 "they may be permanently unreachable from this server. In the latter case,\n%s",
1108 dullmsg, addr->address,
1109 options & vopt_is_recipient
1110 ? "the address will never be accepted."
1111 : "you need to change the address or create an MX record for its domain\n"
1112 "if it is supposed to be generally accessible from the Internet.\n"
1113 "Talk to your mail administrator for details.")
1116 /* Force a specific error code */
1118 addr->basic_errno = ERRNO_CALLOUTDEFER;
1121 /* Come here from within the cache-reading code on fast-track exit. */
1124 tls_modify_variables(&tls_in);
1130 /* Called after recipient-acl to get a cutthrough connection open when
1131 one was requested and a recipient-verify wasn't subsequently done.
1134 open_cutthrough_connection( address_item * addr )
1139 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1140 /* We must use a copy of the address for verification, because it might
1144 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1145 rcpt_count > 1 ? "more" : "start");
1146 rc = verify_address(&addr2, NULL,
1147 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1148 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1150 addr->message = addr2.message;
1151 addr->user_message = addr2.user_message;
1152 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1158 /* Send given number of bytes from the buffer */
1160 cutthrough_send(int n)
1162 if(cutthrough.fd < 0)
1167 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1169 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1172 transport_count += n;
1173 ctblock.ptr= ctblock.buffer;
1177 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1184 _cutthrough_puts(uschar * cp, int n)
1188 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1189 if(!cutthrough_send(ctblock.buffersize))
1192 *ctblock.ptr++ = *cp++;
1197 /* Buffered output of counted data block. Return boolean success */
1199 cutthrough_puts(uschar * cp, int n)
1201 if (cutthrough.fd < 0) return TRUE;
1202 if (_cutthrough_puts(cp, n)) return TRUE;
1203 cancel_cutthrough_connection("transmit failed");
1209 _cutthrough_flush_send(void)
1211 int n= ctblock.ptr-ctblock.buffer;
1214 if(!cutthrough_send(n))
1220 /* Send out any bufferred output. Return boolean success. */
1222 cutthrough_flush_send(void)
1224 if (_cutthrough_flush_send()) return TRUE;
1225 cancel_cutthrough_connection("transmit failed");
1231 cutthrough_put_nl(void)
1233 return cutthrough_puts(US"\r\n", 2);
1237 /* Get and check response from cutthrough target */
1239 cutthrough_response(char expect, uschar ** copy, int timeout)
1241 smtp_inblock inblock;
1242 uschar inbuffer[4096];
1243 uschar responsebuffer[4096];
1245 inblock.buffer = inbuffer;
1246 inblock.buffersize = sizeof(inbuffer);
1247 inblock.ptr = inbuffer;
1248 inblock.ptrend = inbuffer;
1249 inblock.sock = cutthrough.fd;
1250 /* this relies on (inblock.sock == tls_out.active) */
1251 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1252 cancel_cutthrough_connection("target timeout on read");
1257 *copy = cp = string_copy(responsebuffer);
1258 /* Trim the trailing end of line */
1259 cp += Ustrlen(responsebuffer);
1260 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1261 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1264 return responsebuffer[0];
1268 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1270 cutthrough_predata(void)
1272 if(cutthrough.fd < 0)
1275 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1276 cutthrough_puts(US"DATA\r\n", 6);
1277 cutthrough_flush_send();
1279 /* Assume nothing buffered. If it was it gets ignored. */
1280 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1284 /* fd and tctx args only to match write_chunk() */
1286 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1289 while(s && (s2 = Ustrchr(s, '\n')))
1291 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1299 /* Buffered send of headers. Return success boolean. */
1300 /* Expands newlines to wire format (CR,NL). */
1301 /* Also sends header-terminating blank line. */
1303 cutthrough_headers_send(void)
1307 if(cutthrough.fd < 0)
1310 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1311 but having a separate buffered-output function (for now)
1313 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1315 tctx.tblock = cutthrough.addr.transport;
1316 tctx.addr = &cutthrough.addr;
1317 tctx.check_string = US".";
1318 tctx.escape_string = US"..";
1319 tctx.options = topt_use_crlf;
1321 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1324 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1330 close_cutthrough_connection(const char * why)
1332 if(cutthrough.fd >= 0)
1334 /* We could be sending this after a bunch of data, but that is ok as
1335 the only way to cancel the transfer in dataphase is to drop the tcp
1336 conn before the final dot.
1338 ctblock.ptr = ctbuffer;
1339 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1340 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1341 _cutthrough_flush_send();
1343 /* Wait a short time for response, and discard it */
1344 cutthrough_response('2', NULL, 1);
1347 tls_close(FALSE, TRUE);
1349 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1350 (void)close(cutthrough.fd);
1352 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1354 ctblock.ptr = ctbuffer;
1358 cancel_cutthrough_connection(const char * why)
1360 close_cutthrough_connection(why);
1361 cutthrough.delivery = FALSE;
1367 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1368 Log an OK response as a transmission.
1369 Close the connection.
1370 Return smtp response-class digit.
1373 cutthrough_finaldot(void)
1376 address_item * addr;
1377 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1379 /* Assume data finshed with new-line */
1380 if( !cutthrough_puts(US".", 1)
1381 || !cutthrough_put_nl()
1382 || !cutthrough_flush_send()
1384 return cutthrough.addr.message;
1386 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1387 for (addr = &cutthrough.addr; addr; addr = addr->next)
1389 addr->message = cutthrough.addr.message;
1393 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1394 close_cutthrough_connection("delivered");
1398 delivery_log(LOG_MAIN, addr, 0,
1399 US"tmp-reject from cutthrough after DATA:");
1403 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1404 US"rejected after DATA:");
1411 return cutthrough.addr.message;
1416 /*************************************************
1417 * Copy error to toplevel address *
1418 *************************************************/
1420 /* This function is used when a verify fails or defers, to ensure that the
1421 failure or defer information is in the original toplevel address. This applies
1422 when an address is redirected to a single new address, and the failure or
1423 deferral happens to the child address.
1426 vaddr the verify address item
1427 addr the final address item
1430 Returns: the value of YIELD
1434 copy_error(address_item *vaddr, address_item *addr, int yield)
1438 vaddr->message = addr->message;
1439 vaddr->user_message = addr->user_message;
1440 vaddr->basic_errno = addr->basic_errno;
1441 vaddr->more_errno = addr->more_errno;
1442 vaddr->prop.address_data = addr->prop.address_data;
1443 copyflag(vaddr, addr, af_pass_message);
1451 /**************************************************
1452 * printf that automatically handles TLS if needed *
1453 ***************************************************/
1455 /* This function is used by verify_address() as a substitute for all fprintf()
1456 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1457 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1458 that assumes that we always use the smtp_out FILE* when not using TLS or the
1459 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1460 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1464 f the candidate FILE* to write to
1465 format format string
1466 ... optional arguments
1472 static void PRINTF_FUNCTION(2,3)
1473 respond_printf(FILE *f, const char *format, ...)
1477 va_start(ap, format);
1478 if (smtp_out && (f == smtp_out))
1479 smtp_vprintf(format, ap);
1481 vfprintf(f, format, ap);
1487 /*************************************************
1488 * Verify an email address *
1489 *************************************************/
1491 /* This function is used both for verification (-bv and at other times) and
1492 address testing (-bt), which is indicated by address_test_mode being set.
1495 vaddr contains the address to verify; the next field in this block
1497 f if not NULL, write the result to this file
1498 options various option bits:
1499 vopt_fake_sender => this sender verify is not for the real
1500 sender (it was verify=sender=xxxx or an address from a
1501 header line) - rewriting must not change sender_address
1502 vopt_is_recipient => this is a recipient address, otherwise
1503 it's a sender address - this affects qualification and
1504 rewriting and messages from callouts
1505 vopt_qualify => qualify an unqualified address; else error
1506 vopt_expn => called from SMTP EXPN command
1507 vopt_success_on_redirect => when a new address is generated
1508 the verification instantly succeeds
1510 These ones are used by do_callout() -- the options variable
1513 vopt_callout_fullpm => if postmaster check, do full one
1514 vopt_callout_no_cache => don't use callout cache
1515 vopt_callout_random => do the "random" thing
1516 vopt_callout_recipsender => use real sender for recipient
1517 vopt_callout_recippmaster => use postmaster for recipient
1519 callout if > 0, specifies that callout is required, and gives timeout
1520 for individual commands
1521 callout_overall if > 0, gives overall timeout for the callout function;
1522 if < 0, a default is used (see do_callout())
1523 callout_connect the connection timeout for callouts
1524 se_mailfrom when callout is requested to verify a sender, use this
1525 in MAIL FROM; NULL => ""
1526 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1527 thing and use this as the sender address (may be "")
1529 routed if not NULL, set TRUE if routing succeeded, so we can
1530 distinguish between routing failed and callout failed
1532 Returns: OK address verified
1533 FAIL address failed to verify
1534 DEFER can't tell at present
1538 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1539 int callout_overall, int callout_connect, uschar *se_mailfrom,
1540 uschar *pm_mailfrom, BOOL *routed)
1543 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1544 BOOL expn = (options & vopt_expn) != 0;
1545 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1548 int verify_type = expn? v_expn :
1549 address_test_mode? v_none :
1550 options & vopt_is_recipient? v_recipient : v_sender;
1551 address_item *addr_list;
1552 address_item *addr_new = NULL;
1553 address_item *addr_remote = NULL;
1554 address_item *addr_local = NULL;
1555 address_item *addr_succeed = NULL;
1556 uschar **failure_ptr = options & vopt_is_recipient
1557 ? &recipient_verify_failure : &sender_verify_failure;
1558 uschar *ko_prefix, *cr;
1559 uschar *address = vaddr->address;
1560 uschar *save_sender;
1561 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1563 /* Clear, just in case */
1565 *failure_ptr = NULL;
1567 /* Set up a prefix and suffix for error message which allow us to use the same
1568 output statements both in EXPN mode (where an SMTP response is needed) and when
1569 debugging with an output file. */
1573 ko_prefix = US"553 ";
1576 else ko_prefix = cr = US"";
1578 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1580 if (parse_find_at(address) == NULL)
1582 if ((options & vopt_qualify) == 0)
1585 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1586 ko_prefix, address, cr);
1587 *failure_ptr = US"qualify";
1590 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1595 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1596 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1599 /* Rewrite and report on it. Clear the domain and local part caches - these
1600 may have been set by domains and local part tests during an ACL. */
1602 if (global_rewrite_rules != NULL)
1604 uschar *old = address;
1605 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1606 global_rewrite_rules, rewrite_existflags);
1609 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1610 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1611 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1615 /* If this is the real sender address, we must update sender_address at
1616 this point, because it may be referred to in the routers. */
1618 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1619 sender_address = address;
1621 /* If the address was rewritten to <> no verification can be done, and we have
1622 to return OK. This rewriting is permitted only for sender addresses; for other
1623 addresses, such rewriting fails. */
1625 if (address[0] == 0) return OK;
1627 /* Flip the legacy TLS-related variables over to the outbound set in case
1628 they're used in the context of a transport used by verification. Reset them
1629 at exit from this routine (so no returns allowed from here on). */
1631 tls_modify_variables(&tls_out);
1633 /* Save a copy of the sender address for re-instating if we change it to <>
1634 while verifying a sender address (a nice bit of self-reference there). */
1636 save_sender = sender_address;
1638 /* Observability variable for router/transport use */
1640 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1642 /* Update the address structure with the possibly qualified and rewritten
1643 address. Set it up as the starting address on the chain of new addresses. */
1645 vaddr->address = address;
1648 /* We need a loop, because an address can generate new addresses. We must also
1649 cope with generated pipes and files at the top level. (See also the code and
1650 comment in deliver.c.) However, it is usually the case that the router for
1651 user's .forward files has its verify flag turned off.
1653 If an address generates more than one child, the loop is used only when
1654 full_info is set, and this can only be set locally. Remote enquiries just get
1655 information about the top level address, not anything that it generated. */
1660 address_item *addr = addr_new;
1662 addr_new = addr->next;
1667 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1668 debug_printf("Considering %s\n", addr->address);
1671 /* Handle generated pipe, file or reply addresses. We don't get these
1672 when handling EXPN, as it does only one level of expansion. */
1674 if (testflag(addr, af_pfr))
1681 if (addr->address[0] == '>')
1683 allow = testflag(addr, af_allow_reply);
1684 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1688 allow = (addr->address[0] == '|')?
1689 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1690 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1693 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1694 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1695 "%s\n", addr->message);
1697 fprintf(f, "\n transport = %s\n", addr->transport->name);
1699 fprintf(f, " *** forbidden ***\n");
1704 /* Just in case some router parameter refers to it. */
1706 return_path = addr->prop.errors_address
1707 ? addr->prop.errors_address : sender_address;
1709 /* Split the address into domain and local part, handling the %-hack if
1710 necessary, and then route it. While routing a sender address, set
1711 $sender_address to <> because that is what it will be if we were trying to
1712 send a bounce to the sender. */
1714 if (routed) *routed = FALSE;
1715 if ((rc = deliver_split_address(addr)) == OK)
1717 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1718 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1719 &addr_succeed, verify_type);
1720 sender_address = save_sender; /* Put back the real sender */
1723 /* If routing an address succeeded, set the flag that remembers, for use when
1724 an ACL cached a sender verify (in case a callout fails). Then if routing set
1725 up a list of hosts or the transport has a host list, and the callout option
1726 is set, and we aren't in a host checking run, do the callout verification,
1727 and set another flag that notes that a callout happened. */
1731 if (routed) *routed = TRUE;
1734 transport_instance * tp;
1735 host_item * host_list = addr->host_list;
1737 /* Make up some data for use in the case where there is no remote
1740 transport_feedback tf = {
1741 NULL, /* interface (=> any) */
1742 US"smtp", /* port */
1743 US"smtp", /* protocol */
1745 US"$smtp_active_hostname", /* helo_data */
1746 FALSE, /* hosts_override */
1747 FALSE, /* hosts_randomize */
1748 FALSE, /* gethostbyname */
1749 TRUE, /* qualify_single */
1750 FALSE /* search_parents */
1753 /* If verification yielded a remote transport, we want to use that
1754 transport's options, so as to mimic what would happen if we were really
1755 sending a message to this address. */
1757 if ((tp = addr->transport) && !tp->info->local)
1759 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1761 /* If the transport has hosts and the router does not, or if the
1762 transport is configured to override the router's hosts, we must build a
1763 host list of the transport's hosts, and find the IP addresses */
1765 if (tf.hosts && (!host_list || tf.hosts_override))
1768 const uschar *save_deliver_domain = deliver_domain;
1769 uschar *save_deliver_localpart = deliver_localpart;
1771 host_list = NULL; /* Ignore the router's hosts */
1773 deliver_domain = addr->domain;
1774 deliver_localpart = addr->local_part;
1775 s = expand_string(tf.hosts);
1776 deliver_domain = save_deliver_domain;
1777 deliver_localpart = save_deliver_localpart;
1781 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1782 "\"%s\" in %s transport for callout: %s", tf.hosts,
1783 tp->name, expand_string_message);
1788 host_item *host, *nexthost;
1789 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1791 /* Just ignore failures to find a host address. If we don't manage
1792 to find any addresses, the callout will defer. Note that more than
1793 one address may be found for a single host, which will result in
1794 additional host items being inserted into the chain. Hence we must
1795 save the next host first. */
1797 flags = HOST_FIND_BY_A;
1798 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1799 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1801 for (host = host_list; host; host = nexthost)
1803 nexthost = host->next;
1804 if (tf.gethostbyname ||
1805 string_is_ip_address(host->name, NULL) != 0)
1806 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1809 dnssec_domains * dnssec_domains = NULL;
1810 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1812 smtp_transport_options_block * ob =
1813 (smtp_transport_options_block *) tp->options_block;
1814 dnssec_domains = &ob->dnssec;
1817 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1818 dnssec_domains, NULL, NULL);
1825 /* Can only do a callout if we have at least one host! If the callout
1826 fails, it will have set ${sender,recipient}_verify_failure. */
1830 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1831 if (host_checking && !host_checking_callout)
1834 debug_printf("... callout omitted by default when host testing\n"
1835 "(Use -bhc if you want the callouts to happen.)\n");
1840 deliver_set_expansions(addr);
1842 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1843 callout_connect, options, se_mailfrom, pm_mailfrom);
1848 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1849 "transport provided a host list\n");
1854 /* Otherwise, any failure is a routing failure */
1856 else *failure_ptr = US"route";
1858 /* A router may return REROUTED if it has set up a child address as a result
1859 of a change of domain name (typically from widening). In this case we always
1860 want to continue to verify the new child. */
1862 if (rc == REROUTED) continue;
1864 /* Handle hard failures */
1871 address_item *p = addr->parent;
1873 respond_printf(f, "%s%s %s", ko_prefix,
1874 full_info ? addr->address : address,
1875 address_test_mode ? "is undeliverable" : "failed to verify");
1876 if (!expn && admin_user)
1878 if (addr->basic_errno > 0)
1879 respond_printf(f, ": %s", strerror(addr->basic_errno));
1881 respond_printf(f, ": %s", addr->message);
1884 /* Show parents iff doing full info */
1886 if (full_info) while (p)
1888 respond_printf(f, "%s\n <-- %s", cr, p->address);
1891 respond_printf(f, "%s\n", cr);
1893 cancel_cutthrough_connection("routing hard fail");
1897 yield = copy_error(vaddr, addr, FAIL);
1905 else if (rc == DEFER)
1910 address_item *p = addr->parent;
1911 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1912 full_info? addr->address : address);
1913 if (!expn && admin_user)
1915 if (addr->basic_errno > 0)
1916 respond_printf(f, ": %s", strerror(addr->basic_errno));
1918 respond_printf(f, ": %s", addr->message);
1919 else if (addr->basic_errno <= 0)
1920 respond_printf(f, ": unknown error");
1923 /* Show parents iff doing full info */
1925 if (full_info) while (p)
1927 respond_printf(f, "%s\n <-- %s", cr, p->address);
1930 respond_printf(f, "%s\n", cr);
1932 cancel_cutthrough_connection("routing soft fail");
1936 yield = copy_error(vaddr, addr, DEFER);
1939 if (yield == OK) yield = DEFER;
1942 /* If we are handling EXPN, we do not want to continue to route beyond
1943 the top level (whose address is in "address"). */
1947 uschar *ok_prefix = US"250-";
1950 if (!addr_local && !addr_remote)
1951 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1953 respond_printf(f, "250 <%s>\r\n", address);
1957 address_item *addr2 = addr_new;
1958 addr_new = addr2->next;
1959 if (!addr_new) ok_prefix = US"250 ";
1960 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1966 /* Successful routing other than EXPN. */
1970 /* Handle successful routing when short info wanted. Otherwise continue for
1971 other (generated) addresses. Short info is the operational case. Full info
1972 can be requested only when debug_selector != 0 and a file is supplied.
1974 There is a conflict between the use of aliasing as an alternate email
1975 address, and as a sort of mailing list. If an alias turns the incoming
1976 address into just one address (e.g. J.Caesar->jc44) you may well want to
1977 carry on verifying the generated address to ensure it is valid when
1978 checking incoming mail. If aliasing generates multiple addresses, you
1979 probably don't want to do this. Exim therefore treats the generation of
1980 just a single new address as a special case, and continues on to verify the
1981 generated address. */
1983 if ( !full_info /* Stop if short info wanted AND */
1984 && ( ( !addr_new /* No new address OR */
1985 || addr_new->next /* More than one new address OR */
1986 || testflag(addr_new, af_pfr) /* New address is pfr */
1989 ( addr_new /* At least one new address AND */
1990 && success_on_redirect /* success_on_redirect is set */
1994 if (f) fprintf(f, "%s %s\n",
1995 address, address_test_mode ? "is deliverable" : "verified");
1997 /* If we have carried on to verify a child address, we want the value
1998 of $address_data to be that of the child */
2000 vaddr->prop.address_data = addr->prop.address_data;
2002 /* If stopped because more than one new address, cannot cutthrough */
2004 if (addr_new && addr_new->next)
2005 cancel_cutthrough_connection("multiple addresses from routing");
2011 } /* Loop for generated addresses */
2013 /* Display the full results of the successful routing, including any generated
2014 addresses. Control gets here only when full_info is set, which requires f not
2015 to be NULL, and this occurs only when a top-level verify is called with the
2016 debugging switch on.
2018 If there are no local and no remote addresses, and there were no pipes, files,
2019 or autoreplies, and there were no errors or deferments, the message is to be
2020 discarded, usually because of the use of :blackhole: in an alias file. */
2022 if (allok && !addr_local && !addr_remote)
2024 fprintf(f, "mail to %s is discarded\n", address);
2028 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2031 address_item *addr = addr_list;
2032 address_item *p = addr->parent;
2033 transport_instance * tp = addr->transport;
2035 addr_list = addr->next;
2037 fprintf(f, "%s", CS addr->address);
2038 #ifdef EXPERIMENTAL_SRS
2039 if(addr->prop.srs_sender)
2040 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2043 /* If the address is a duplicate, show something about it. */
2045 if (!testflag(addr, af_pfr))
2048 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2049 fprintf(f, " [duplicate, would not be delivered]");
2050 else tree_add_duplicate(addr->unique, addr);
2053 /* Now show its parents */
2055 for (p = addr->parent; p; p = p->parent)
2056 fprintf(f, "\n <-- %s", p->address);
2059 /* Show router, and transport */
2061 fprintf(f, "router = %s, transport = %s\n",
2062 addr->router->name, tp ? tp->name : US"unset");
2064 /* Show any hosts that are set up by a router unless the transport
2065 is going to override them; fiddle a bit to get a nice format. */
2067 if (addr->host_list && tp && !tp->overrides_hosts)
2072 for (h = addr->host_list; h; h = h->next)
2073 { /* get max lengths of host names, addrs */
2074 int len = Ustrlen(h->name);
2075 if (len > maxlen) maxlen = len;
2076 len = h->address ? Ustrlen(h->address) : 7;
2077 if (len > maxaddlen) maxaddlen = len;
2079 for (h = addr->host_list; h; h = h->next)
2081 fprintf(f, " host %-*s ", maxlen, h->name);
2084 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2085 else if (tp->info->local)
2086 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2088 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2090 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2091 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2092 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2093 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2099 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2100 the -bv or -bt case). */
2104 tls_modify_variables(&tls_in);
2112 /*************************************************
2113 * Check headers for syntax errors *
2114 *************************************************/
2116 /* This function checks those header lines that contain addresses, and verifies
2117 that all the addresses therein are syntactially correct.
2120 msgptr where to put an error message
2127 verify_check_headers(uschar **msgptr)
2133 for (h = header_list; h != NULL && yield == OK; h = h->next)
2135 if (h->type != htype_from &&
2136 h->type != htype_reply_to &&
2137 h->type != htype_sender &&
2138 h->type != htype_to &&
2139 h->type != htype_cc &&
2140 h->type != htype_bcc)
2143 colon = Ustrchr(h->text, ':');
2145 while (isspace(*s)) s++;
2147 /* Loop for multiple addresses in the header, enabling group syntax. Note
2148 that we have to reset this after the header has been scanned. */
2150 parse_allow_group = TRUE;
2154 uschar *ss = parse_find_address_end(s, FALSE);
2155 uschar *recipient, *errmess;
2156 int terminator = *ss;
2157 int start, end, domain;
2159 /* Temporarily terminate the string at this point, and extract the
2160 operative address within, allowing group syntax. */
2163 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2166 /* Permit an unqualified address only if the message is local, or if the
2167 sending host is configured to be permitted to send them. */
2169 if (recipient != NULL && domain == 0)
2171 if (h->type == htype_from || h->type == htype_sender)
2173 if (!allow_unqualified_sender) recipient = NULL;
2177 if (!allow_unqualified_recipient) recipient = NULL;
2179 if (recipient == NULL) errmess = US"unqualified address not permitted";
2182 /* It's an error if no address could be extracted, except for the special
2183 case of an empty address. */
2185 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2187 uschar *verb = US"is";
2192 /* Arrange not to include any white space at the end in the
2193 error message or the header name. */
2195 while (t > s && isspace(t[-1])) t--;
2196 while (tt > h->text && isspace(tt[-1])) tt--;
2198 /* Add the address that failed to the error message, since in a
2199 header with very many addresses it is sometimes hard to spot
2200 which one is at fault. However, limit the amount of address to
2201 quote - cases have been seen where, for example, a missing double
2202 quote in a humungous To: header creates an "address" that is longer
2203 than string_sprintf can handle. */
2212 /* deconst cast ok as we're passing a non-const to string_printing() */
2213 *msgptr = US string_printing(
2214 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2215 errmess, tt - h->text, h->text, verb, len, s));
2218 break; /* Out of address loop */
2221 /* Advance to the next address */
2223 s = ss + (terminator? 1:0);
2224 while (isspace(*s)) s++;
2225 } /* Next address */
2227 parse_allow_group = FALSE;
2228 parse_found_group = FALSE;
2229 } /* Next header unless yield has been set FALSE */
2235 /*************************************************
2236 * Check header names for 8-bit characters *
2237 *************************************************/
2239 /* This function checks for invalid characters in header names. See
2240 RFC 5322, 2.2. and RFC 6532, 3.
2243 msgptr where to put an error message
2250 verify_check_header_names_ascii(uschar **msgptr)
2255 for (h = header_list; h != NULL; h = h->next)
2257 colon = Ustrchr(h->text, ':');
2258 for(s = h->text; s < colon; s++)
2260 if ((*s < 33) || (*s > 126))
2262 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2263 colon - h->text, h->text);
2271 /*************************************************
2272 * Check for blind recipients *
2273 *************************************************/
2275 /* This function checks that every (envelope) recipient is mentioned in either
2276 the To: or Cc: header lines, thus detecting blind carbon copies.
2278 There are two ways of scanning that could be used: either scan the header lines
2279 and tick off the recipients, or scan the recipients and check the header lines.
2280 The original proposed patch did the former, but I have chosen to do the latter,
2281 because (a) it requires no memory and (b) will use fewer resources when there
2282 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2285 Returns: OK if there are no blind recipients
2286 FAIL if there is at least one blind recipient
2290 verify_check_notblind(void)
2293 for (i = 0; i < recipients_count; i++)
2297 uschar *address = recipients_list[i].address;
2299 for (h = header_list; !found && h != NULL; h = h->next)
2303 if (h->type != htype_to && h->type != htype_cc) continue;
2305 colon = Ustrchr(h->text, ':');
2307 while (isspace(*s)) s++;
2309 /* Loop for multiple addresses in the header, enabling group syntax. Note
2310 that we have to reset this after the header has been scanned. */
2312 parse_allow_group = TRUE;
2316 uschar *ss = parse_find_address_end(s, FALSE);
2317 uschar *recipient,*errmess;
2318 int terminator = *ss;
2319 int start, end, domain;
2321 /* Temporarily terminate the string at this point, and extract the
2322 operative address within, allowing group syntax. */
2325 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2328 /* If we found a valid recipient that has a domain, compare it with the
2329 envelope recipient. Local parts are compared case-sensitively, domains
2330 case-insensitively. By comparing from the start with length "domain", we
2331 include the "@" at the end, which ensures that we are comparing the whole
2332 local part of each address. */
2334 if (recipient != NULL && domain != 0)
2336 found = Ustrncmp(recipient, address, domain) == 0 &&
2337 strcmpic(recipient + domain, address + domain) == 0;
2341 /* Advance to the next address */
2343 s = ss + (terminator? 1:0);
2344 while (isspace(*s)) s++;
2345 } /* Next address */
2347 parse_allow_group = FALSE;
2348 parse_found_group = FALSE;
2349 } /* Next header (if found is false) */
2351 if (!found) return FAIL;
2352 } /* Next recipient */
2359 /*************************************************
2360 * Find if verified sender *
2361 *************************************************/
2363 /* Usually, just a single address is verified as the sender of the message.
2364 However, Exim can be made to verify other addresses as well (often related in
2365 some way), and this is useful in some environments. There may therefore be a
2366 chain of such addresses that have previously been tested. This function finds
2367 whether a given address is on the chain.
2369 Arguments: the address to be verified
2370 Returns: pointer to an address item, or NULL
2374 verify_checked_sender(uschar *sender)
2377 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2378 if (Ustrcmp(sender, addr->address) == 0) break;
2386 /*************************************************
2387 * Get valid header address *
2388 *************************************************/
2390 /* Scan the originator headers of the message, looking for an address that
2391 verifies successfully. RFC 822 says:
2393 o The "Sender" field mailbox should be sent notices of
2394 any problems in transport or delivery of the original
2395 messages. If there is no "Sender" field, then the
2396 "From" field mailbox should be used.
2398 o If the "Reply-To" field exists, then the reply should
2399 go to the addresses indicated in that field and not to
2400 the address(es) indicated in the "From" field.
2402 So we check a Sender field if there is one, else a Reply_to field, else a From
2403 field. As some strange messages may have more than one of these fields,
2404 especially if they are resent- fields, check all of them if there is more than
2408 user_msgptr points to where to put a user error message
2409 log_msgptr points to where to put a log error message
2410 callout timeout for callout check (passed to verify_address())
2411 callout_overall overall callout timeout (ditto)
2412 callout_connect connect callout timeout (ditto)
2413 se_mailfrom mailfrom for verify; NULL => ""
2414 pm_mailfrom sender for pm callout check (passed to verify_address())
2415 options callout options (passed to verify_address())
2416 verrno where to put the address basic_errno
2418 If log_msgptr is set to something without setting user_msgptr, the caller
2419 normally uses log_msgptr for both things.
2421 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2422 FAIL is given if no appropriate headers are found
2426 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2427 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2428 uschar *pm_mailfrom, int options, int *verrno)
2430 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2435 for (i = 0; i < 3 && !done; i++)
2438 for (h = header_list; h != NULL && !done; h = h->next)
2440 int terminator, new_ok;
2441 uschar *s, *ss, *endname;
2443 if (h->type != header_types[i]) continue;
2444 s = endname = Ustrchr(h->text, ':') + 1;
2446 /* Scan the addresses in the header, enabling group syntax. Note that we
2447 have to reset this after the header has been scanned. */
2449 parse_allow_group = TRUE;
2453 address_item *vaddr;
2455 while (isspace(*s) || *s == ',') s++;
2456 if (*s == 0) break; /* End of header */
2458 ss = parse_find_address_end(s, FALSE);
2460 /* The terminator is a comma or end of header, but there may be white
2461 space preceding it (including newline for the last address). Move back
2462 past any white space so we can check against any cached envelope sender
2463 address verifications. */
2465 while (isspace(ss[-1])) ss--;
2469 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2470 (int)(endname - h->text), h->text, s);
2472 /* See if we have already verified this address as an envelope sender,
2473 and if so, use the previous answer. */
2475 vaddr = verify_checked_sender(s);
2477 if (vaddr != NULL && /* Previously checked */
2478 (callout <= 0 || /* No callout needed; OR */
2479 vaddr->special_action > 256)) /* Callout was done */
2481 new_ok = vaddr->special_action & 255;
2482 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2483 *ss = terminator; /* Restore shortened string */
2486 /* Otherwise we run the verification now. We must restore the shortened
2487 string before running the verification, so the headers are correct, in
2488 case there is any rewriting. */
2492 int start, end, domain;
2493 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2498 /* If we found an empty address, just carry on with the next one, but
2499 kill the message. */
2501 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2508 /* If verification failed because of a syntax error, fail this
2509 function, and ensure that the failing address gets added to the error
2512 if (address == NULL)
2515 while (ss > s && isspace(ss[-1])) ss--;
2516 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2517 "scanning for sender: %s in \"%.*s\"",
2518 endname - h->text, h->text, *log_msgptr, ss - s, s);
2524 /* Else go ahead with the sender verification. But it isn't *the*
2525 sender of the message, so set vopt_fake_sender to stop sender_address
2526 being replaced after rewriting or qualification. */
2530 vaddr = deliver_make_addr(address, FALSE);
2531 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2532 callout, callout_overall, callout_connect, se_mailfrom,
2537 /* We now have the result, either newly found, or cached. If we are
2538 giving out error details, set a specific user error. This means that the
2539 last of these will be returned to the user if all three fail. We do not
2540 set a log message - the generic one below will be used. */
2544 *verrno = vaddr->basic_errno;
2545 if (smtp_return_error_details)
2547 *user_msgptr = string_sprintf("Rejected after DATA: "
2548 "could not verify \"%.*s\" header address\n%s: %s",
2549 endname - h->text, h->text, vaddr->address, vaddr->message);
2553 /* Success or defer */
2562 if (new_ok == DEFER) yield = DEFER;
2564 /* Move on to any more addresses in the header */
2567 } /* Next address */
2569 parse_allow_group = FALSE;
2570 parse_found_group = FALSE;
2571 } /* Next header, unless done */
2572 } /* Next header type unless done */
2574 if (yield == FAIL && *log_msgptr == NULL)
2575 *log_msgptr = US"there is no valid sender in any header line";
2577 if (yield == DEFER && *log_msgptr == NULL)
2578 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2586 /*************************************************
2587 * Get RFC 1413 identification *
2588 *************************************************/
2590 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2591 the timeout is set to zero, then the query is not done. There may also be lists
2592 of hosts and nets which are exempt. To guard against malefactors sending
2593 non-printing characters which could, for example, disrupt a message's headers,
2594 make sure the string consists of printing characters only.
2597 port the port to connect to; usually this is IDENT_PORT (113), but when
2598 running in the test harness with -bh a different value is used.
2602 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2606 verify_get_ident(int port)
2608 int sock, host_af, qlen;
2609 int received_sender_port, received_interface_port, n;
2611 uschar buffer[2048];
2613 /* Default is no ident. Check whether we want to do an ident check for this
2616 sender_ident = NULL;
2617 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2620 DEBUG(D_ident) debug_printf("doing ident callback\n");
2622 /* Set up a connection to the ident port of the remote host. Bind the local end
2623 to the incoming interface address. If the sender host address is an IPv6
2624 address, the incoming interface address will also be IPv6. */
2626 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2627 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2629 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2631 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2636 if (ip_connect(sock, host_af, sender_host_address, port,
2637 rfc1413_query_timeout, TRUE) < 0)
2639 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2640 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2641 sender_host_address);
2643 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2644 sender_host_address, strerror(errno));
2648 /* Construct and send the query. */
2650 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2651 qlen = Ustrlen(buffer);
2652 if (send(sock, buffer, qlen, 0) < 0)
2654 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2658 /* Read a response line. We put it into the rest of the buffer, using several
2659 recv() calls if necessary. */
2667 int size = sizeof(buffer) - (p - buffer);
2669 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2670 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2671 if (count <= 0) goto END_OFF; /* Read error or EOF */
2673 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2674 generous, and accept a plain \n terminator as well. The only illegal
2677 for (pp = p; pp < p + count; pp++)
2679 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2682 if (pp[-1] == '\r') pp--;
2684 goto GOT_DATA; /* Break out of both loops */
2688 /* Reached the end of the data without finding \n. Let the loop continue to
2689 read some more, if there is room. */
2696 /* We have received a line of data. Check it carefully. It must start with the
2697 same two port numbers that we sent, followed by data as defined by the RFC. For
2700 12345 , 25 : USERID : UNIX :root
2702 However, the amount of white space may be different to what we sent. In the
2703 "osname" field there may be several sub-fields, comma separated. The data we
2704 actually want to save follows the third colon. Some systems put leading spaces
2705 in it - we discard those. */
2707 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2708 &received_interface_port, &n) != 2 ||
2709 received_sender_port != sender_host_port ||
2710 received_interface_port != interface_port)
2713 p = buffer + qlen + n;
2714 while(isspace(*p)) p++;
2715 if (*p++ != ':') goto END_OFF;
2716 while(isspace(*p)) p++;
2717 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2719 while(isspace(*p)) p++;
2720 if (*p++ != ':') goto END_OFF;
2721 while (*p != 0 && *p != ':') p++;
2722 if (*p++ == 0) goto END_OFF;
2723 while(isspace(*p)) p++;
2724 if (*p == 0) goto END_OFF;
2726 /* The rest of the line is the data we want. We turn it into printing
2727 characters when we save it, so that it cannot mess up the format of any logging
2728 or Received: lines into which it gets inserted. We keep a maximum of 127
2729 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2731 sender_ident = US string_printing(string_copyn(p, 127));
2732 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2742 /*************************************************
2743 * Match host to a single host-list item *
2744 *************************************************/
2746 /* This function compares a host (name or address) against a single item
2747 from a host list. The host name gets looked up if it is needed and is not
2748 already known. The function is called from verify_check_this_host() via
2749 match_check_list(), which is why most of its arguments are in a single block.
2752 arg the argument block (see below)
2753 ss the host-list item
2754 valueptr where to pass back looked up data, or NULL
2755 error for error message when returning ERROR
2758 host_name (a) the host name, or
2759 (b) NULL, implying use sender_host_name and
2760 sender_host_aliases, looking them up if required, or
2761 (c) the empty string, meaning that only IP address matches
2763 host_address the host address
2764 host_ipv4 the IPv4 address taken from an IPv6 one
2768 DEFER lookup deferred
2769 ERROR (a) failed to find the host name or IP address, or
2770 (b) unknown lookup type specified, or
2771 (c) host name encountered when only IP addresses are
2776 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2778 check_host_block *cb = (check_host_block *)arg;
2781 BOOL iplookup = FALSE;
2782 BOOL isquery = FALSE;
2783 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2788 /* Optimize for the special case when the pattern is "*". */
2790 if (*ss == '*' && ss[1] == 0) return OK;
2792 /* If the pattern is empty, it matches only in the case when there is no host -
2793 this can occur in ACL checking for SMTP input using the -bs option. In this
2794 situation, the host address is the empty string. */
2796 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2797 if (*ss == 0) return FAIL;
2799 /* If the pattern is precisely "@" then match against the primary host name,
2800 provided that host name matching is permitted; if it's "@[]" match against the
2801 local host's IP addresses. */
2807 if (isiponly) return ERROR;
2808 ss = primary_hostname;
2810 else if (Ustrcmp(ss, "@[]") == 0)
2812 ip_address_item *ip;
2813 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2814 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2819 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2820 a (possibly masked) comparison with the current IP address. */
2822 if (string_is_ip_address(ss, &maskoffset) != 0)
2823 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2825 /* The pattern is not an IP address. A common error that people make is to omit
2826 one component of an IPv4 address, either by accident, or believing that, for
2827 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,
2828 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2829 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2830 ancient specification.) To aid in debugging these cases, we give a specific
2831 error if the pattern contains only digits and dots or contains a slash preceded
2832 only by digits and dots (a slash at the start indicates a file name and of
2833 course slashes may be present in lookups, but not preceded only by digits and
2836 for (t = ss; isdigit(*t) || *t == '.'; t++);
2837 if (*t == 0 || (*t == '/' && t != ss))
2839 *error = US"malformed IPv4 address or address mask";
2843 /* See if there is a semicolon in the pattern */
2845 semicolon = Ustrchr(ss, ';');
2847 /* If we are doing an IP address only match, then all lookups must be IP
2848 address lookups, even if there is no "net-". */
2852 iplookup = semicolon != NULL;
2855 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2856 a lookup on a masked IP network, in textual form. We obey this code even if we
2857 have already set iplookup, so as to skip over the "net-" prefix and to set the
2858 mask length. The net- stuff really only applies to single-key lookups where the
2859 key is implicit. For query-style lookups the key is specified in the query.
2860 From release 4.30, the use of net- for query style is no longer needed, but we
2861 retain it for backward compatibility. */
2863 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2866 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2867 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2868 iplookup = (*t++ == '-');
2872 /* Do the IP address lookup if that is indeed what we have */
2880 uschar *filename, *key, *result;
2883 /* Find the search type */
2885 search_type = search_findtype(t, semicolon - t);
2887 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2888 search_error_message);
2890 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2891 is no file name, and the "key" is just the query. For query-style with a file
2892 name, we have to fish the file off the start of the query. For a single-key
2893 lookup, the key is the current IP address, masked appropriately, and
2894 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2895 dot separators instead of colons, except when the lookup type is "iplsearch".
2898 if (mac_islookup(search_type, lookup_absfilequery))
2900 filename = semicolon + 1;
2902 while (*key != 0 && !isspace(*key)) key++;
2903 filename = string_copyn(filename, key - filename);
2904 while (isspace(*key)) key++;
2906 else if (mac_islookup(search_type, lookup_querystyle))
2909 key = semicolon + 1;
2911 else /* Single-key style */
2913 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2915 insize = host_aton(cb->host_address, incoming);
2916 host_mask(insize, incoming, mlen);
2917 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2919 filename = semicolon + 1;
2922 /* Now do the actual lookup; note that there is no search_close() because
2923 of the caching arrangements. */
2925 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2926 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2928 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2929 if (valueptr != NULL) *valueptr = result;
2930 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2933 /* The pattern is not an IP address or network reference of any kind. That is,
2934 it is a host name pattern. If this is an IP only match, there's an error in the
2939 *error = US"cannot match host name in match_ip list";
2943 /* Check the characters of the pattern to see if they comprise only letters,
2944 digits, full stops, and hyphens (the constituents of domain names). Allow
2945 underscores, as they are all too commonly found. Sigh. Also, if
2946 allow_utf8_domains is set, allow top-bit characters. */
2948 for (t = ss; *t != 0; t++)
2949 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2950 (!allow_utf8_domains || *t < 128)) break;
2952 /* If the pattern is a complete domain name, with no fancy characters, look up
2953 its IP address and match against that. Note that a multi-homed host will add
2954 items to the chain. */
2965 /* Using byname rather than bydns here means we cannot determine dnssec
2966 status. On the other hand it is unclear how that could be either
2967 propagated up or enforced. */
2969 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2970 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2973 for (hh = &h; hh != NULL; hh = hh->next)
2975 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2979 if (rc == HOST_FIND_AGAIN) return DEFER;
2980 *error = string_sprintf("failed to find IP address for %s", ss);
2984 /* Almost all subsequent comparisons require the host name, and can be done
2985 using the general string matching function. When this function is called for
2986 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2987 must use sender_host_name and its aliases, looking them up if necessary. */
2989 if (cb->host_name != NULL) /* Explicit host name given */
2990 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2993 /* Host name not given; in principle we need the sender host name and its
2994 aliases. However, for query-style lookups, we do not need the name if the
2995 query does not contain $sender_host_name. From release 4.23, a reference to
2996 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2999 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3001 const uschar *affix;
3002 int partial, affixlen, starflags, id;
3005 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3008 if (id < 0) /* Unknown lookup type */
3010 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3011 search_error_message, ss);
3014 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3019 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3022 case DEFER: return DEFER;
3023 default: return FAIL;
3027 /* Not a query-style lookup; must ensure the host name is present, and then we
3028 do a check on the name and all its aliases. */
3030 if (sender_host_name == NULL)
3032 HDEBUG(D_host_lookup)
3033 debug_printf("sender host name required, to match against %s\n", ss);
3034 if (host_lookup_failed || host_name_lookup() != OK)
3036 *error = string_sprintf("failed to find host name for %s",
3037 sender_host_address);;
3040 host_build_sender_fullhost();
3043 /* Match on the sender host name, using the general matching function */
3045 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3049 case DEFER: return DEFER;
3052 /* If there are aliases, try matching on them. */
3054 aliases = sender_host_aliases;
3055 while (*aliases != NULL)
3057 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3060 case DEFER: return DEFER;
3069 /*************************************************
3070 * Check a specific host matches a host list *
3071 *************************************************/
3073 /* This function is passed a host list containing items in a number of
3074 different formats and the identity of a host. Its job is to determine whether
3075 the given host is in the set of hosts defined by the list. The host name is
3076 passed as a pointer so that it can be looked up if needed and not already
3077 known. This is commonly the case when called from verify_check_host() to check
3078 an incoming connection. When called from elsewhere the host name should usually
3081 This function is now just a front end to match_check_list(), which runs common
3082 code for scanning a list. We pass it the check_host() function to perform a
3086 listptr pointer to the host list
3087 cache_bits pointer to cache for named lists, or NULL
3088 host_name the host name or NULL, implying use sender_host_name and
3089 sender_host_aliases, looking them up if required
3090 host_address the IP address
3091 valueptr if not NULL, data from a lookup is passed back here
3093 Returns: OK if the host is in the defined set
3094 FAIL if the host is not in the defined set,
3095 DEFER if a data lookup deferred (not a host lookup)
3097 If the host name was needed in order to make a comparison, and could not be
3098 determined from the IP address, the result is FAIL unless the item
3099 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3102 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3103 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3106 unsigned int *local_cache_bits = cache_bits;
3107 const uschar *save_host_address = deliver_host_address;
3108 check_host_block cb;
3109 cb.host_name = host_name;
3110 cb.host_address = host_address;
3112 if (valueptr != NULL) *valueptr = NULL;
3114 /* If the host address starts off ::ffff: it is an IPv6 address in
3115 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3118 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3119 host_address + 7 : host_address;
3121 /* During the running of the check, put the IP address into $host_address. In
3122 the case of calls from the smtp transport, it will already be there. However,
3123 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3124 the safe side, any existing setting is preserved, though as I write this
3125 (November 2004) I can't see any cases where it is actually needed. */
3127 deliver_host_address = host_address;
3128 rc = match_check_list(
3129 listptr, /* the list */
3130 0, /* separator character */
3131 &hostlist_anchor, /* anchor pointer */
3132 &local_cache_bits, /* cache pointer */
3133 check_host, /* function for testing */
3134 &cb, /* argument for function */
3135 MCL_HOST, /* type of check */
3136 (host_address == sender_host_address)?
3137 US"host" : host_address, /* text for debugging */
3138 valueptr); /* where to pass back data */
3139 deliver_host_address = save_host_address;
3146 /*************************************************
3147 * Check the given host item matches a list *
3148 *************************************************/
3150 verify_check_given_host(uschar **listptr, host_item *host)
3152 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3155 /*************************************************
3156 * Check the remote host matches a list *
3157 *************************************************/
3159 /* This is a front end to verify_check_this_host(), created because checking
3160 the remote host is a common occurrence. With luck, a good compiler will spot
3161 the tail recursion and optimize it. If there's no host address, this is
3162 command-line SMTP input - check against an empty string for the address.
3165 listptr pointer to the host list
3167 Returns: the yield of verify_check_this_host(),
3168 i.e. OK, FAIL, or DEFER
3172 verify_check_host(uschar **listptr)
3174 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3175 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3182 /*************************************************
3183 * Invert an IP address *
3184 *************************************************/
3186 /* Originally just used for DNS xBL lists, now also used for the
3187 reverse_ip expansion operator.
3190 buffer where to put the answer
3191 address the address to invert
3195 invert_address(uschar *buffer, uschar *address)
3198 uschar *bptr = buffer;
3200 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3201 to the IPv4 part only. */
3203 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3205 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3208 if (host_aton(address, bin) == 1)
3212 for (i = 0; i < 4; i++)
3214 sprintf(CS bptr, "%d.", x & 255);
3215 while (*bptr) bptr++;
3220 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3221 in any DNS black lists, and the format in which they will be looked up is
3222 unknown. This is just a guess. */
3228 for (j = 3; j >= 0; j--)
3231 for (i = 0; i < 8; i++)
3233 sprintf(CS bptr, "%x.", x & 15);
3234 while (*bptr) bptr++;
3241 /* Remove trailing period -- this is needed so that both arbitrary
3242 dnsbl keydomains and inverted addresses may be combined with the
3243 same format string, "%s.%s" */
3250 /*************************************************
3251 * Perform a single dnsbl lookup *
3252 *************************************************/
3254 /* This function is called from verify_check_dnsbl() below. It is also called
3255 recursively from within itself when domain and domain_txt are different
3256 pointers, in order to get the TXT record from the alternate domain.
3259 domain the outer dnsbl domain
3260 domain_txt alternate domain to lookup TXT record on success; when the
3261 same domain is to be used, domain_txt == domain (that is,
3262 the pointers must be identical, not just the text)
3263 keydomain the current keydomain (for debug message)
3264 prepend subdomain to lookup (like keydomain, but
3265 reversed if IP address)
3266 iplist the list of matching IP addresses, or NULL for "any"
3267 bitmask true if bitmask matching is wanted
3268 match_type condition for 'succeed' result
3269 0 => Any RR in iplist (=)
3270 1 => No RR in iplist (!=)
3271 2 => All RRs in iplist (==)
3272 3 => Some RRs not in iplist (!==)
3273 the two bits are defined as MT_NOT and MT_ALL
3274 defer_return what to return for a defer
3276 Returns: OK if lookup succeeded
3281 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3282 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3288 dnsbl_cache_block *cb;
3289 int old_pool = store_pool;
3290 uschar query[256]; /* DNS domain max length */
3292 /* Construct the specific query domainname */
3294 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3296 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3297 "(ignored): %s...", query);
3301 /* Look for this query in the cache. */
3303 if ( (t = tree_search(dnsbl_cache, query))
3304 && (cb = t->data.ptr)->expiry > time(NULL)
3307 /* Previous lookup was cached */
3310 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3313 /* If not cached from a previous lookup, we must do a DNS lookup, and
3314 cache the result in permanent memory. */
3320 store_pool = POOL_PERM;
3324 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3328 { /* Set up a tree entry to cache the lookup */
3329 t = store_get(sizeof(tree_node) + Ustrlen(query));
3330 Ustrcpy(t->name, query);
3331 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3332 (void)tree_insertnode(&dnsbl_cache, t);
3335 /* Do the DNS lookup . */
3337 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3338 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3339 cb->text_set = FALSE;
3343 /* If the lookup succeeded, cache the RHS address. The code allows for
3344 more than one address - this was for complete generality and the possible
3345 use of A6 records. However, A6 records have been reduced to experimental
3346 status (August 2001) and may die out. So they may never get used at all,
3347 let alone in dnsbl records. However, leave the code here, just in case.
3349 Quite apart from one A6 RR generating multiple addresses, there are DNS
3350 lists that return more than one A record, so we must handle multiple
3351 addresses generated in that way as well.
3353 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3354 or some suitably far-future time if none were found. */
3356 if (cb->rc == DNS_SUCCEED)
3359 dns_address **addrp = &(cb->rhs);
3360 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3362 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3364 if (rr->type == T_A)
3366 dns_address *da = dns_address_from_rr(&dnsa, rr);
3370 while (da->next != NULL) da = da->next;
3371 addrp = &(da->next);
3372 if (ttl > rr->ttl) ttl = rr->ttl;
3377 /* If we didn't find any A records, change the return code. This can
3378 happen when there is a CNAME record but there are no A records for what
3381 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3384 cb->expiry = time(NULL)+ttl;
3385 store_pool = old_pool;
3388 /* We now have the result of the DNS lookup, either newly done, or cached
3389 from a previous call. If the lookup succeeded, check against the address
3390 list if there is one. This may be a positive equality list (introduced by
3391 "="), a negative equality list (introduced by "!="), a positive bitmask
3392 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3394 if (cb->rc == DNS_SUCCEED)
3396 dns_address *da = NULL;
3397 uschar *addlist = cb->rhs->address;
3399 /* For A and AAAA records, there may be multiple addresses from multiple
3400 records. For A6 records (currently not expected to be used) there may be
3401 multiple addresses from a single record. */
3403 for (da = cb->rhs->next; da != NULL; da = da->next)
3404 addlist = string_sprintf("%s, %s", addlist, da->address);
3406 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3409 /* Address list check; this can be either for equality, or via a bitmask.
3410 In the latter case, all the bits must match. */
3414 for (da = cb->rhs; da != NULL; da = da->next)
3418 const uschar *ptr = iplist;
3421 /* Handle exact matching */
3425 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3427 if (Ustrcmp(CS da->address, ip) == 0) break;
3431 /* Handle bitmask matching */
3438 /* At present, all known DNS blocking lists use A records, with
3439 IPv4 addresses on the RHS encoding the information they return. I
3440 wonder if this will linger on as the last vestige of IPv4 when IPv6
3441 is ubiquitous? Anyway, for now we use paranoia code to completely
3442 ignore IPv6 addresses. The default mask is 0, which always matches.
3443 We change this only for IPv4 addresses in the list. */
3445 if (host_aton(da->address, address) == 1) mask = address[0];
3447 /* Scan the returned addresses, skipping any that are IPv6 */
3449 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3451 if (host_aton(ip, address) != 1) continue;
3452 if ((address[0] & mask) == address[0]) break;
3458 (a) An IP address in an any ('=') list matched, or
3459 (b) No IP address in an all ('==') list matched
3461 then we're done searching. */
3463 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3466 /* If da == NULL, either
3468 (a) No IP address in an any ('=') list matched, or
3469 (b) An IP address in an all ('==') list didn't match
3471 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3474 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3482 res = US"was no match";
3485 res = US"was an exclude match";
3488 res = US"was an IP address that did not match";
3491 res = US"were no IP addresses that did not match";
3494 debug_printf("=> but we are not accepting this block class because\n");
3495 debug_printf("=> there %s for %s%c%s\n",
3497 ((match_type & MT_ALL) == 0)? "" : "=",
3498 bitmask? '&' : '=', iplist);
3504 /* Either there was no IP list, or the record matched, implying that the
3505 domain is on the list. We now want to find a corresponding TXT record. If an
3506 alternate domain is specified for the TXT record, call this function
3507 recursively to look that up; this has the side effect of re-checking that
3508 there is indeed an A record at the alternate domain. */
3510 if (domain_txt != domain)
3511 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3512 FALSE, match_type, defer_return);
3514 /* If there is no alternate domain, look up a TXT record in the main domain
3515 if it has not previously been cached. */
3519 cb->text_set = TRUE;
3520 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3523 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3525 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3526 if (rr->type == T_TXT) break;
3529 int len = (rr->data)[0];
3530 if (len > 511) len = 127;
3531 store_pool = POOL_PERM;
3532 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3533 store_pool = old_pool;
3538 dnslist_value = addlist;
3539 dnslist_text = cb->text;
3543 /* There was a problem with the DNS lookup */
3545 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3547 log_write(L_dnslist_defer, LOG_MAIN,
3548 "DNS list lookup defer (probably timeout) for %s: %s", query,
3549 (defer_return == OK)? US"assumed in list" :
3550 (defer_return == FAIL)? US"assumed not in list" :
3551 US"returned DEFER");
3552 return defer_return;
3555 /* No entry was found in the DNS; continue for next domain */
3559 debug_printf("DNS lookup for %s failed\n", query);
3560 debug_printf("=> that means %s is not listed at %s\n",
3570 /*************************************************
3571 * Check host against DNS black lists *
3572 *************************************************/
3574 /* This function runs checks against a list of DNS black lists, until one
3575 matches. Each item on the list can be of the form
3577 domain=ip-address/key
3579 The domain is the right-most domain that is used for the query, for example,
3580 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3581 if the DNS lookup returns a matching IP address. Several addresses may be
3582 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3584 If no key is given, what is looked up in the domain is the inverted IP address
3585 of the current client host. If a key is given, it is used to construct the
3586 domain for the lookup. For example:
3588 dsn.rfc-ignorant.org/$sender_address_domain
3590 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3591 then we check for a TXT record for an error message, and if found, save its
3592 value in $dnslist_text. We also cache everything in a tree, to optimize
3595 The TXT record is normally looked up in the same domain as the A record, but
3596 when many lists are combined in a single DNS domain, this will not be a very
3597 specific message. It is possible to specify a different domain for looking up
3598 TXT records; this is given before the main domain, comma-separated. For
3601 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3602 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3604 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3606 Note: an address for testing RBL is 192.203.178.39
3607 Note: an address for testing DUL is 192.203.178.4
3608 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3612 listptr the domain/address/data list
3613 log_msgptr log message on error
3615 Returns: OK successful lookup (i.e. the address is on the list), or
3616 lookup deferred after +include_unknown
3617 FAIL name not found, or no data found for the given type, or
3618 lookup deferred after +exclude_unknown (default)
3619 DEFER lookup failure, if +defer_unknown was set
3623 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3626 int defer_return = FAIL;
3627 const uschar *list = *listptr;
3630 uschar buffer[1024];
3631 uschar revadd[128]; /* Long enough for IPv6 address */
3633 /* Indicate that the inverted IP address is not yet set up */
3637 /* In case this is the first time the DNS resolver is being used. */
3639 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3641 /* Loop through all the domains supplied, until something matches */
3643 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3646 BOOL bitmask = FALSE;
3653 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3655 /* Deal with special values that change the behaviour on defer */
3657 if (domain[0] == '+')
3659 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3660 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3661 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3663 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3668 /* See if there's explicit data to be looked up */
3670 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3672 /* See if there's a list of addresses supplied after the domain name. This is
3673 introduced by an = or a & character; if preceded by = we require all matches
3674 and if preceded by ! we invert the result. */
3676 if (!(iplist = Ustrchr(domain, '=')))
3679 iplist = Ustrchr(domain, '&');
3682 if (iplist) /* Found either = or & */
3684 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3686 match_type |= MT_NOT;
3690 *iplist++ = 0; /* Terminate domain, move on */
3692 /* If we found = (bitmask == FALSE), check for == or =& */
3694 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3696 bitmask = *iplist++ == '&';
3697 match_type |= MT_ALL;
3702 /* If there is a comma in the domain, it indicates that a second domain for
3703 looking up TXT records is provided, before the main domain. Otherwise we must
3704 set domain_txt == domain. */
3706 domain_txt = domain;
3707 comma = Ustrchr(domain, ',');
3714 /* Check that what we have left is a sensible domain name. There is no reason
3715 why these domains should in fact use the same syntax as hosts and email
3716 domains, but in practice they seem to. However, there is little point in
3717 actually causing an error here, because that would no doubt hold up incoming
3718 mail. Instead, I'll just log it. */
3720 for (s = domain; *s != 0; s++)
3722 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3724 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3725 "strange characters - is this right?", domain);
3730 /* Check the alternate domain if present */
3732 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3734 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3736 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3737 "strange characters - is this right?", domain_txt);
3742 /* If there is no key string, construct the query by adding the domain name
3743 onto the inverted host address, and perform a single DNS lookup. */
3747 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3749 *log_msgptr = string_sprintf
3750 ("cannot test auto-keyed dnslists condition in %s ACL",
3751 acl_wherenames[where]);
3754 if (sender_host_address == NULL) return FAIL; /* can never match */
3755 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3756 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3757 iplist, bitmask, match_type, defer_return);
3760 dnslist_domain = string_copy(domain_txt);
3761 dnslist_matched = string_copy(sender_host_address);
3762 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3763 sender_host_address, dnslist_domain);
3765 if (rc != FAIL) return rc; /* OK or DEFER */
3768 /* If there is a key string, it can be a list of domains or IP addresses to
3769 be concatenated with the main domain. */
3776 uschar keybuffer[256];
3777 uschar keyrevadd[128];
3779 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3780 sizeof(keybuffer))) != NULL)
3782 uschar *prepend = keydomain;
3784 if (string_is_ip_address(keydomain, NULL) != 0)
3786 invert_address(keyrevadd, keydomain);
3787 prepend = keyrevadd;
3790 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3791 bitmask, match_type, defer_return);
3795 dnslist_domain = string_copy(domain_txt);
3796 dnslist_matched = string_copy(keydomain);
3797 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3798 keydomain, dnslist_domain);
3802 /* If the lookup deferred, remember this fact. We keep trying the rest
3803 of the list to see if we get a useful result, and if we don't, we return
3804 DEFER at the end. */
3806 if (rc == DEFER) defer = TRUE;
3807 } /* continue with next keystring domain/address */
3809 if (defer) return DEFER;
3811 } /* continue with next dnsdb outer domain */
3818 /* End of verify.c */