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(int, 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, ':') ? AF_INET6 : AF_INET;
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(cutthrough.fd, '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(TRUE, US"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(TRUE, US"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 vopt_callout_hold => lazy close connection
494 se_mailfrom MAIL FROM address for sender verify; NULL => ""
495 pm_mailfrom if non-NULL, do the postmaster check with this sender
497 Returns: OK/FAIL/DEFER
501 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
502 int callout, int callout_overall, int callout_connect, int options,
503 uschar *se_mailfrom, uschar *pm_mailfrom)
506 int old_domain_cache_result = ccache_accept;
509 uschar *from_address;
510 uschar *random_local_part = NULL;
511 const uschar *save_deliver_domain = deliver_domain;
512 uschar **failure_ptr = options & vopt_is_recipient
513 ? &recipient_verify_failure : &sender_verify_failure;
514 dbdata_callout_cache new_domain_record;
515 dbdata_callout_cache_address new_address_record;
516 time_t callout_start_time;
518 new_domain_record.result = ccache_unknown;
519 new_domain_record.postmaster_result = ccache_unknown;
520 new_domain_record.random_result = ccache_unknown;
522 memset(&new_address_record, 0, sizeof(new_address_record));
524 /* For a recipient callout, the key used for the address cache record must
525 include the sender address if we are using the real sender in the callout,
526 because that may influence the result of the callout. */
528 if (options & vopt_is_recipient)
529 if (options & vopt_callout_recipsender)
531 from_address = sender_address;
532 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
533 if (cutthrough.delivery) options |= vopt_callout_no_cache;
535 else if (options & vopt_callout_recippmaster)
537 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
538 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
539 qualify_domain_sender);
544 address_key = addr->address;
547 /* For a sender callout, we must adjust the key if the mailfrom address is not
552 from_address = se_mailfrom ? se_mailfrom : US"";
553 address_key = *from_address
554 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
557 if (cached_callout_lookup(addr, address_key, from_address,
558 &options, &pm_mailfrom, &yield, failure_ptr,
559 &new_domain_record, &old_domain_cache_result))
561 cancel_cutthrough_connection(TRUE, US"cache-hit");
565 if (!addr->transport)
567 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
569 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
570 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
571 addr->transport->name, addr->transport->driver_name);
574 smtp_transport_options_block *ob =
575 (smtp_transport_options_block *)addr->transport->options_block;
578 /* The information wasn't available in the cache, so we have to do a real
579 callout and save the result in the cache for next time, unless no_cache is set,
580 or unless we have a previously cached negative random result. If we are to test
581 with a random local part, ensure that such a local part is available. If not,
582 log the fact, but carry on without randomising. */
584 if (options & vopt_callout_random && callout_random_local_part)
585 if (!(random_local_part = expand_string(callout_random_local_part)))
586 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
587 "callout_random_local_part: %s", expand_string_message);
589 /* Default the connect and overall callout timeouts if not set, and record the
590 time we are starting so that we can enforce it. */
592 if (callout_overall < 0) callout_overall = 4 * callout;
593 if (callout_connect < 0) callout_connect = callout;
594 callout_start_time = time(NULL);
596 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
597 output because a callout might take some time. When PIPELINING is active and
598 there are many recipients, the total time for doing lots of callouts can add up
599 and cause the client to time out. So in this case we forgo the PIPELINING
602 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
604 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
605 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
607 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
608 and we are holding a cutthrough conn open, we can just append the rcpt to
609 that conn for verification purposes (and later delivery also). Simplest
610 coding means skipping this whole loop and doing the append separately. */
612 /* Can we re-use an open cutthrough connection? */
613 if ( cutthrough.fd >= 0
614 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
615 == vopt_callout_recipsender
616 && !random_local_part
619 done = cutthrough_multi(addr, host_list, tf, &yield);
621 /* If we did not use a cached connection, make connections to the hosts
622 and do real callouts. The list of hosts is passed in as an argument. */
624 for (host = host_list; host && !done; host = host->next)
628 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
633 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
638 /* Check the overall callout timeout */
640 if (time(NULL) - callout_start_time >= callout_overall)
642 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
646 /* Set IPv4 or IPv6 */
648 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
650 /* Expand and interpret the interface and port strings. The latter will not
651 be used if there is a host-specific port (e.g. from a manualroute router).
652 This has to be delayed till now, because they may expand differently for
653 different hosts. If there's a failure, log it, but carry on with the
656 deliver_host = host->name;
657 deliver_host_address = host->address;
658 deliver_host_port = host->port;
659 deliver_domain = addr->domain;
660 transport_name = addr->transport->name;
662 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
664 || !smtp_get_port(tf->port, addr, &port, US"callout")
666 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
671 sx.host_af = host_af,
673 sx.interface = interface;
674 sx.helo_data = tf->helo_data;
675 sx.tblock = addr->transport;
678 tls_retry_connection:
679 /* Set the address state so that errors are recorded in it */
681 addr->transport_return = PENDING_DEFER;
682 ob->connect_timeout = callout_connect;
683 ob->command_timeout = callout;
685 /* Get the channel set up ready for a message (MAIL FROM being the next
686 SMTP command to send. If we tried TLS but it failed, try again without
689 yield = smtp_setup_conn(&sx, FALSE);
692 && addr->basic_errno == ERRNO_TLSFAILURE
693 && ob->tls_tempfail_tryclear
694 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
697 log_write(0, LOG_MAIN,
698 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
699 addr->message, host->name, host->address);
700 addr->transport_return = PENDING_DEFER;
701 yield = smtp_setup_conn(&sx, TRUE);
706 errno = addr->basic_errno;
707 transport_name = NULL;
708 deliver_host = deliver_host_address = NULL;
709 deliver_domain = save_deliver_domain;
711 /* Failure to accept HELO is cached; this blocks the whole domain for all
712 senders. I/O errors and defer responses are not cached. */
714 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
716 setflag(addr, af_verify_nsfail);
717 new_domain_record.result = ccache_reject;
725 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
726 the AUTH info for logging */
728 addr->authenticator = client_authenticator;
729 addr->auth_id = client_authenticated_id;
731 sx.from_addr = from_address;
732 sx.first_addr = sx.sync_addr = addr;
733 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
735 sx.completed_addr = FALSE;
737 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
738 ? ccache_reject_mfnull : ccache_accept;
740 /* Do the random local part check first. Temporarily replace the recipient
741 with the "random" value */
743 if (random_local_part)
745 uschar * main_address = addr->address;
746 const uschar * rcpt_domain = addr->domain;
749 uschar * errstr = NULL;
750 if ( testflag(addr, af_utf8_downcvt)
751 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
755 addr->message = errstr;
756 errno = ERRNO_EXPANDFAIL;
757 setflag(addr, af_verify_nsfail);
759 rcpt_domain = US""; /*XXX errorhandling! */
763 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
764 subsequents are done in cutthrough_multi()), but no way to
765 handle a subsequent because of the RSET vaporising the MAIL FROM.
766 So refuse to support any. Most cutthrough use will not involve
767 random_local_part, so no loss. */
768 cancel_cutthrough_connection(TRUE, US"random-recipient");
770 addr->address = string_sprintf("%s@%.1000s",
771 random_local_part, rcpt_domain);
774 /* If accepted, we aren't going to do any further tests below.
775 Otherwise, cache a real negative response, and get back to the right
776 state to send RCPT. Unless there's some problem such as a dropped
777 connection, we expect to succeed, because the commands succeeded above.
778 However, some servers drop the connection after responding to an
779 invalid recipient, so on (any) error we drop and remake the connection.
780 XXX We don't care about that for postmaster_full. Should we?
782 XXX could we add another flag to the context, and have the common
783 code emit the RSET too? Even pipelined after the RCPT...
784 Then the main-verify call could use it if there's to be a subsequent
786 The sync_responses() would need to be taught about it and we'd
787 need another return code filtering out to here.
790 /* Remember when we last did a random test */
791 new_domain_record.random_stamp = time(NULL);
793 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
794 switch(addr->transport_return)
797 new_domain_record.random_result = ccache_accept;
800 new_domain_record.random_result = ccache_reject;
802 /* Between each check, issue RSET, because some servers accept only
803 one recipient after MAIL FROM:<>.
804 XXX We don't care about that for postmaster_full. Should we? */
807 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
808 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
813 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
814 random_local_part = NULL;
816 tls_close(FALSE, TRUE);
818 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
819 (void)close(sx.inblock.sock);
820 sx.inblock.sock = sx.outblock.sock = -1;
821 #ifndef DISABLE_EVENT
822 (void) event_raise(addr->transport->event_action,
823 US"tcp:close", NULL);
825 addr->address = main_address;
826 addr->transport_return = PENDING_DEFER;
827 sx.first_addr = sx.sync_addr = addr;
830 sx.completed_addr = FALSE;
831 goto tls_retry_connection;
834 /* Re-setup for main verify, or for the error message when failing */
835 addr->address = main_address;
836 addr->transport_return = PENDING_DEFER;
837 sx.first_addr = sx.sync_addr = addr;
840 sx.completed_addr = FALSE;
845 /* Main verify. If the host is accepting all local parts, as determined
846 by the "random" check, we don't need to waste time doing any further
852 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
854 case 0: switch(addr->transport_return) /* ok so far */
856 case PENDING_OK: done = TRUE;
857 new_address_record.result = ccache_accept;
859 case FAIL: done = TRUE;
861 *failure_ptr = US"recipient";
862 new_address_record.result = ccache_reject;
868 case -1: /* MAIL response error */
869 *failure_ptr = US"mail";
870 if (errno == 0 && sx.buffer[0] == '5')
872 setflag(addr, af_verify_nsfail);
873 if (from_address[0] == 0)
874 new_domain_record.result = ccache_reject_mfnull;
877 /* non-MAIL read i/o error */
878 /* non-MAIL response timeout */
879 /* internal error; channel still usable */
880 default: break; /* transmit failed */
884 addr->auth_sndr = client_authenticated_sender;
886 deliver_host = deliver_host_address = NULL;
887 deliver_domain = save_deliver_domain;
889 /* Do postmaster check if requested; if a full check is required, we
890 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
892 if (done && pm_mailfrom)
894 /* Could possibly shift before main verify, just above, and be ok
895 for cutthrough. But no way to handle a subsequent rcpt, so just
897 cancel_cutthrough_connection(TRUE, US"postmaster verify");
898 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
900 done = smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0
901 && smtp_read_response(&sx.inblock, sx.buffer,
902 sizeof(sx.buffer), '2', callout);
906 uschar * main_address = addr->address;
908 /*XXX oops, affixes */
909 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
910 addr->transport_return = PENDING_DEFER;
912 sx.from_addr = pm_mailfrom;
913 sx.first_addr = sx.sync_addr = addr;
916 sx.completed_addr = FALSE;
918 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
919 && addr->transport_return == PENDING_OK
923 done = (options & vopt_callout_fullpm) != 0
924 && smtp_write_command(&sx.outblock, FALSE,
925 "RCPT TO:<postmaster>\r\n") >= 0
926 && smtp_read_response(&sx.inblock, sx.buffer,
927 sizeof(sx.buffer), '2', callout);
929 /* Sort out the cache record */
931 new_domain_record.postmaster_stamp = time(NULL);
934 new_domain_record.postmaster_result = ccache_accept;
935 else if (errno == 0 && sx.buffer[0] == '5')
937 *failure_ptr = US"postmaster";
938 setflag(addr, af_verify_pmfail);
939 new_domain_record.postmaster_result = ccache_reject;
942 addr->address = main_address;
945 /* For any failure of the main check, other than a negative response, we just
946 close the connection and carry on. We can identify a negative response by the
947 fact that errno is zero. For I/O errors it will be non-zero
949 Set up different error texts for logging and for sending back to the caller
950 as an SMTP response. Log in all cases, using a one-line format. For sender
951 callouts, give a full response to the caller, but for recipient callouts,
952 don't give the IP address because this may be an internal host whose identity
953 is not to be widely broadcast. */
959 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
960 sx.send_quit = FALSE;
966 extern int acl_where; /* src/acl.c */
968 addr->message = string_sprintf(
969 "response to \"EHLO\" did not include SMTPUTF8");
970 addr->user_message = acl_where == ACL_WHERE_RCPT
971 ? US"533 no support for internationalised mailbox name"
972 : US"550 mailbox unavailable";
979 sx.send_quit = FALSE;
983 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
985 /*XXX test here is ugly; seem to have a split of responsibility for
986 building this message. Need to reationalise. Where is it done
987 before here, and when not?
988 Not == 5xx resp to MAIL on main-verify
990 if (!addr->message) addr->message =
991 string_sprintf("response to \"%s\" was: %s",
992 big_buffer, string_printing(sx.buffer));
994 addr->user_message = options & vopt_is_recipient
995 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
996 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
997 host->address, big_buffer, sx.buffer);
999 /* Hard rejection ends the process */
1001 if (sx.buffer[0] == '5') /* Address rejected */
1009 /* End the SMTP conversation and close the connection. */
1011 /* Cutthrough - on a successful connect and recipient-verify with
1012 use-sender and we are 1st rcpt and have no cutthrough conn so far
1013 here is where we want to leave the conn open. Ditto for a lazy-close
1016 if ( (cutthrough.delivery || options & vopt_callout_hold)
1020 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1021 == vopt_callout_recipsender
1022 && !random_local_part
1024 && cutthrough.fd < 0
1028 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1030 ? "cutthrough delivery" : "potential further verifies and delivery");
1032 cutthrough.callout_hold_only = !cutthrough.delivery;
1033 cutthrough.is_tls = tls_out.active >= 0;
1034 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1035 cutthrough.nrcpt = 1;
1036 cutthrough.transport = addr->transport->name;
1037 cutthrough.interface = interface;
1038 cutthrough.snd_port = sending_port;
1039 cutthrough.peer_options = smtp_peer_options;
1040 cutthrough.host = *host;
1042 int oldpool = store_pool;
1043 store_pool = POOL_PERM;
1044 cutthrough.snd_ip = string_copy(sending_ip_address);
1045 cutthrough.host.name = string_copy(host->name);
1046 cutthrough.host.address = string_copy(host->address);
1047 store_pool = oldpool;
1049 cutthrough.addr = *addr; /* Save the address_item for later logging */
1050 cutthrough.addr.next = NULL;
1051 cutthrough.addr.host_used = &cutthrough.host;
1053 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1055 ctblock.buffer = ctbuffer;
1056 ctblock.buffersize = sizeof(ctbuffer);
1057 ctblock.ptr = ctbuffer;
1058 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1059 ctblock.sock = cutthrough.fd;
1063 /* Ensure no cutthrough on multiple verifies that were incompatible */
1064 if (options & vopt_callout_recipsender)
1065 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1068 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1070 /* Wait a short time for response, and discard it */
1071 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1075 if (sx.inblock.sock >= 0)
1078 tls_close(FALSE, TRUE);
1080 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1081 (void)close(sx.inblock.sock);
1082 sx.inblock.sock = sx.outblock.sock = -1;
1083 #ifndef DISABLE_EVENT
1084 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1089 if (!done || yield != OK)
1090 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1092 } /* Loop through all hosts, while !done */
1095 /* If we get here with done == TRUE, a successful callout happened, and yield
1096 will be set OK or FAIL according to the response to the RCPT command.
1097 Otherwise, we looped through the hosts but couldn't complete the business.
1098 However, there may be domain-specific information to cache in both cases. */
1100 if (!(options & vopt_callout_no_cache))
1101 cache_callout_write(&new_domain_record, addr->domain,
1102 done, &new_address_record, address_key);
1104 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1105 temporary error. If there was only one host, and a response was received, leave
1106 it alone if supplying details. Otherwise, give a generic response. */
1110 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1111 options & vopt_is_recipient ? "recipient" : "sender");
1114 addr->message = host_list->next || !addr->message
1115 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1117 addr->user_message = smtp_return_error_details
1118 ? string_sprintf("%s for <%s>.\n"
1119 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1120 "they may be permanently unreachable from this server. In the latter case,\n%s",
1121 dullmsg, addr->address,
1122 options & vopt_is_recipient
1123 ? "the address will never be accepted."
1124 : "you need to change the address or create an MX record for its domain\n"
1125 "if it is supposed to be generally accessible from the Internet.\n"
1126 "Talk to your mail administrator for details.")
1129 /* Force a specific error code */
1131 addr->basic_errno = ERRNO_CALLOUTDEFER;
1134 /* Come here from within the cache-reading code on fast-track exit. */
1137 tls_modify_variables(&tls_in);
1143 /* Called after recipient-acl to get a cutthrough connection open when
1144 one was requested and a recipient-verify wasn't subsequently done.
1147 open_cutthrough_connection( address_item * addr )
1152 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1153 /* We must use a copy of the address for verification, because it might
1157 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1158 rcpt_count > 1 ? "more" : "start");
1159 rc = verify_address(&addr2, NULL,
1160 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1161 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1163 addr->message = addr2.message;
1164 addr->user_message = addr2.user_message;
1165 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1171 /* Send given number of bytes from the buffer */
1173 cutthrough_send(int n)
1175 if(cutthrough.fd < 0)
1180 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1182 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1185 transport_count += n;
1186 ctblock.ptr= ctblock.buffer;
1190 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1197 _cutthrough_puts(uschar * cp, int n)
1201 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1202 if(!cutthrough_send(ctblock.buffersize))
1205 *ctblock.ptr++ = *cp++;
1210 /* Buffered output of counted data block. Return boolean success */
1212 cutthrough_puts(uschar * cp, int n)
1214 if (cutthrough.fd < 0) return TRUE;
1215 if (_cutthrough_puts(cp, n)) return TRUE;
1216 cancel_cutthrough_connection(TRUE, US"transmit failed");
1221 cutthrough_data_puts(uschar * cp, int n)
1223 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1228 _cutthrough_flush_send(void)
1230 int n = ctblock.ptr - ctblock.buffer;
1233 if(!cutthrough_send(n))
1239 /* Send out any bufferred output. Return boolean success. */
1241 cutthrough_flush_send(void)
1243 if (_cutthrough_flush_send()) return TRUE;
1244 cancel_cutthrough_connection(TRUE, US"transmit failed");
1250 cutthrough_put_nl(void)
1252 return cutthrough_puts(US"\r\n", 2);
1257 cutthrough_data_put_nl(void)
1259 cutthrough_data_puts(US"\r\n", 2);
1263 /* Get and check response from cutthrough target */
1265 cutthrough_response(int fd, char expect, uschar ** copy, int timeout)
1267 smtp_inblock inblock;
1268 uschar inbuffer[4096];
1269 uschar responsebuffer[4096];
1271 inblock.buffer = inbuffer;
1272 inblock.buffersize = sizeof(inbuffer);
1273 inblock.ptr = inbuffer;
1274 inblock.ptrend = inbuffer;
1276 /* this relies on (inblock.sock == tls_out.active) */
1277 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1278 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1283 *copy = cp = string_copy(responsebuffer);
1284 /* Trim the trailing end of line */
1285 cp += Ustrlen(responsebuffer);
1286 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1287 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1290 return responsebuffer[0];
1294 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1296 cutthrough_predata(void)
1298 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1301 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1302 cutthrough_puts(US"DATA\r\n", 6);
1303 cutthrough_flush_send();
1305 /* Assume nothing buffered. If it was it gets ignored. */
1306 return cutthrough_response(cutthrough.fd, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1310 /* fd and tctx args only to match write_chunk() */
1312 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1315 while(s && (s2 = Ustrchr(s, '\n')))
1317 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1325 /* Buffered send of headers. Return success boolean. */
1326 /* Expands newlines to wire format (CR,NL). */
1327 /* Also sends header-terminating blank line. */
1329 cutthrough_headers_send(void)
1333 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1336 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1337 but having a separate buffered-output function (for now)
1339 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1341 tctx.tblock = cutthrough.addr.transport;
1342 tctx.addr = &cutthrough.addr;
1343 tctx.check_string = US".";
1344 tctx.escape_string = US"..";
1345 tctx.options = topt_use_crlf;
1347 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1350 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1356 close_cutthrough_connection(const char * why)
1358 int fd = cutthrough.fd;
1361 /* We could be sending this after a bunch of data, but that is ok as
1362 the only way to cancel the transfer in dataphase is to drop the tcp
1363 conn before the final dot.
1365 ctblock.ptr = ctbuffer;
1366 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1367 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1368 _cutthrough_flush_send();
1369 cutthrough.fd = -1; /* avoid recursion via read timeout */
1371 /* Wait a short time for response, and discard it */
1372 cutthrough_response(fd, '2', NULL, 1);
1375 tls_close(FALSE, TRUE);
1377 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1379 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1381 ctblock.ptr = ctbuffer;
1385 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1387 if (cutthrough.delivery || close_noncutthrough_verifies)
1388 close_cutthrough_connection(why);
1389 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1394 release_cutthrough_connection(const uschar * why)
1396 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1398 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1404 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1405 Log an OK response as a transmission.
1406 Close the connection.
1407 Return smtp response-class digit.
1410 cutthrough_finaldot(void)
1413 address_item * addr;
1414 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1416 /* Assume data finshed with new-line */
1417 if( !cutthrough_puts(US".", 1)
1418 || !cutthrough_put_nl()
1419 || !cutthrough_flush_send()
1421 return cutthrough.addr.message;
1423 res = cutthrough_response(cutthrough.fd, '2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1424 for (addr = &cutthrough.addr; addr; addr = addr->next)
1426 addr->message = cutthrough.addr.message;
1430 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1431 close_cutthrough_connection("delivered");
1435 delivery_log(LOG_MAIN, addr, 0,
1436 US"tmp-reject from cutthrough after DATA:");
1440 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1441 US"rejected after DATA:");
1448 return cutthrough.addr.message;
1453 /*************************************************
1454 * Copy error to toplevel address *
1455 *************************************************/
1457 /* This function is used when a verify fails or defers, to ensure that the
1458 failure or defer information is in the original toplevel address. This applies
1459 when an address is redirected to a single new address, and the failure or
1460 deferral happens to the child address.
1463 vaddr the verify address item
1464 addr the final address item
1467 Returns: the value of YIELD
1471 copy_error(address_item *vaddr, address_item *addr, int yield)
1475 vaddr->message = addr->message;
1476 vaddr->user_message = addr->user_message;
1477 vaddr->basic_errno = addr->basic_errno;
1478 vaddr->more_errno = addr->more_errno;
1479 vaddr->prop.address_data = addr->prop.address_data;
1480 copyflag(vaddr, addr, af_pass_message);
1488 /**************************************************
1489 * printf that automatically handles TLS if needed *
1490 ***************************************************/
1492 /* This function is used by verify_address() as a substitute for all fprintf()
1493 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1494 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1495 that assumes that we always use the smtp_out FILE* when not using TLS or the
1496 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1497 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1501 f the candidate FILE* to write to
1502 format format string
1503 ... optional arguments
1509 static void PRINTF_FUNCTION(2,3)
1510 respond_printf(FILE *f, const char *format, ...)
1514 va_start(ap, format);
1515 if (smtp_out && (f == smtp_out))
1516 smtp_vprintf(format, ap);
1518 vfprintf(f, format, ap);
1524 /*************************************************
1525 * Verify an email address *
1526 *************************************************/
1528 /* This function is used both for verification (-bv and at other times) and
1529 address testing (-bt), which is indicated by address_test_mode being set.
1532 vaddr contains the address to verify; the next field in this block
1534 f if not NULL, write the result to this file
1535 options various option bits:
1536 vopt_fake_sender => this sender verify is not for the real
1537 sender (it was verify=sender=xxxx or an address from a
1538 header line) - rewriting must not change sender_address
1539 vopt_is_recipient => this is a recipient address, otherwise
1540 it's a sender address - this affects qualification and
1541 rewriting and messages from callouts
1542 vopt_qualify => qualify an unqualified address; else error
1543 vopt_expn => called from SMTP EXPN command
1544 vopt_success_on_redirect => when a new address is generated
1545 the verification instantly succeeds
1547 These ones are used by do_callout() -- the options variable
1550 vopt_callout_fullpm => if postmaster check, do full one
1551 vopt_callout_no_cache => don't use callout cache
1552 vopt_callout_random => do the "random" thing
1553 vopt_callout_recipsender => use real sender for recipient
1554 vopt_callout_recippmaster => use postmaster for recipient
1556 callout if > 0, specifies that callout is required, and gives timeout
1557 for individual commands
1558 callout_overall if > 0, gives overall timeout for the callout function;
1559 if < 0, a default is used (see do_callout())
1560 callout_connect the connection timeout for callouts
1561 se_mailfrom when callout is requested to verify a sender, use this
1562 in MAIL FROM; NULL => ""
1563 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1564 thing and use this as the sender address (may be "")
1566 routed if not NULL, set TRUE if routing succeeded, so we can
1567 distinguish between routing failed and callout failed
1569 Returns: OK address verified
1570 FAIL address failed to verify
1571 DEFER can't tell at present
1575 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1576 int callout_overall, int callout_connect, uschar *se_mailfrom,
1577 uschar *pm_mailfrom, BOOL *routed)
1580 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1581 BOOL expn = (options & vopt_expn) != 0;
1582 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1585 int verify_type = expn? v_expn :
1586 address_test_mode? v_none :
1587 options & vopt_is_recipient? v_recipient : v_sender;
1588 address_item *addr_list;
1589 address_item *addr_new = NULL;
1590 address_item *addr_remote = NULL;
1591 address_item *addr_local = NULL;
1592 address_item *addr_succeed = NULL;
1593 uschar **failure_ptr = options & vopt_is_recipient
1594 ? &recipient_verify_failure : &sender_verify_failure;
1595 uschar *ko_prefix, *cr;
1596 uschar *address = vaddr->address;
1597 uschar *save_sender;
1598 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1600 /* Clear, just in case */
1602 *failure_ptr = NULL;
1604 /* Set up a prefix and suffix for error message which allow us to use the same
1605 output statements both in EXPN mode (where an SMTP response is needed) and when
1606 debugging with an output file. */
1610 ko_prefix = US"553 ";
1613 else ko_prefix = cr = US"";
1615 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1617 if (parse_find_at(address) == NULL)
1619 if ((options & vopt_qualify) == 0)
1622 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1623 ko_prefix, address, cr);
1624 *failure_ptr = US"qualify";
1627 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1632 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1633 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1636 /* Rewrite and report on it. Clear the domain and local part caches - these
1637 may have been set by domains and local part tests during an ACL. */
1639 if (global_rewrite_rules != NULL)
1641 uschar *old = address;
1642 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1643 global_rewrite_rules, rewrite_existflags);
1646 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1647 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1648 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1652 /* If this is the real sender address, we must update sender_address at
1653 this point, because it may be referred to in the routers. */
1655 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1656 sender_address = address;
1658 /* If the address was rewritten to <> no verification can be done, and we have
1659 to return OK. This rewriting is permitted only for sender addresses; for other
1660 addresses, such rewriting fails. */
1662 if (address[0] == 0) return OK;
1664 /* Flip the legacy TLS-related variables over to the outbound set in case
1665 they're used in the context of a transport used by verification. Reset them
1666 at exit from this routine (so no returns allowed from here on). */
1668 tls_modify_variables(&tls_out);
1670 /* Save a copy of the sender address for re-instating if we change it to <>
1671 while verifying a sender address (a nice bit of self-reference there). */
1673 save_sender = sender_address;
1675 /* Observability variable for router/transport use */
1677 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1679 /* Update the address structure with the possibly qualified and rewritten
1680 address. Set it up as the starting address on the chain of new addresses. */
1682 vaddr->address = address;
1685 /* We need a loop, because an address can generate new addresses. We must also
1686 cope with generated pipes and files at the top level. (See also the code and
1687 comment in deliver.c.) However, it is usually the case that the router for
1688 user's .forward files has its verify flag turned off.
1690 If an address generates more than one child, the loop is used only when
1691 full_info is set, and this can only be set locally. Remote enquiries just get
1692 information about the top level address, not anything that it generated. */
1697 address_item *addr = addr_new;
1699 addr_new = addr->next;
1704 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1705 debug_printf("Considering %s\n", addr->address);
1708 /* Handle generated pipe, file or reply addresses. We don't get these
1709 when handling EXPN, as it does only one level of expansion. */
1711 if (testflag(addr, af_pfr))
1718 if (addr->address[0] == '>')
1720 allow = testflag(addr, af_allow_reply);
1721 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1725 allow = (addr->address[0] == '|')?
1726 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1727 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1730 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1731 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1732 "%s\n", addr->message);
1734 fprintf(f, "\n transport = %s\n", addr->transport->name);
1736 fprintf(f, " *** forbidden ***\n");
1741 /* Just in case some router parameter refers to it. */
1743 return_path = addr->prop.errors_address
1744 ? addr->prop.errors_address : sender_address;
1746 /* Split the address into domain and local part, handling the %-hack if
1747 necessary, and then route it. While routing a sender address, set
1748 $sender_address to <> because that is what it will be if we were trying to
1749 send a bounce to the sender. */
1751 if (routed) *routed = FALSE;
1752 if ((rc = deliver_split_address(addr)) == OK)
1754 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1755 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1756 &addr_succeed, verify_type);
1757 sender_address = save_sender; /* Put back the real sender */
1760 /* If routing an address succeeded, set the flag that remembers, for use when
1761 an ACL cached a sender verify (in case a callout fails). Then if routing set
1762 up a list of hosts or the transport has a host list, and the callout option
1763 is set, and we aren't in a host checking run, do the callout verification,
1764 and set another flag that notes that a callout happened. */
1768 if (routed) *routed = TRUE;
1771 transport_instance * tp;
1772 host_item * host_list = addr->host_list;
1774 /* Make up some data for use in the case where there is no remote
1777 transport_feedback tf = {
1778 NULL, /* interface (=> any) */
1779 US"smtp", /* port */
1780 US"smtp", /* protocol */
1782 US"$smtp_active_hostname", /* helo_data */
1783 FALSE, /* hosts_override */
1784 FALSE, /* hosts_randomize */
1785 FALSE, /* gethostbyname */
1786 TRUE, /* qualify_single */
1787 FALSE /* search_parents */
1790 /* If verification yielded a remote transport, we want to use that
1791 transport's options, so as to mimic what would happen if we were really
1792 sending a message to this address. */
1794 if ((tp = addr->transport) && !tp->info->local)
1796 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1798 /* If the transport has hosts and the router does not, or if the
1799 transport is configured to override the router's hosts, we must build a
1800 host list of the transport's hosts, and find the IP addresses */
1802 if (tf.hosts && (!host_list || tf.hosts_override))
1805 const uschar *save_deliver_domain = deliver_domain;
1806 uschar *save_deliver_localpart = deliver_localpart;
1808 host_list = NULL; /* Ignore the router's hosts */
1810 deliver_domain = addr->domain;
1811 deliver_localpart = addr->local_part;
1812 s = expand_string(tf.hosts);
1813 deliver_domain = save_deliver_domain;
1814 deliver_localpart = save_deliver_localpart;
1818 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1819 "\"%s\" in %s transport for callout: %s", tf.hosts,
1820 tp->name, expand_string_message);
1825 host_item *host, *nexthost;
1826 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1828 /* Just ignore failures to find a host address. If we don't manage
1829 to find any addresses, the callout will defer. Note that more than
1830 one address may be found for a single host, which will result in
1831 additional host items being inserted into the chain. Hence we must
1832 save the next host first. */
1834 flags = HOST_FIND_BY_A;
1835 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1836 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1838 for (host = host_list; host; host = nexthost)
1840 nexthost = host->next;
1841 if (tf.gethostbyname ||
1842 string_is_ip_address(host->name, NULL) != 0)
1843 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1846 dnssec_domains * dnssec_domains = NULL;
1847 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1849 smtp_transport_options_block * ob =
1850 (smtp_transport_options_block *) tp->options_block;
1851 dnssec_domains = &ob->dnssec;
1854 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1855 dnssec_domains, NULL, NULL);
1862 /* Can only do a callout if we have at least one host! If the callout
1863 fails, it will have set ${sender,recipient}_verify_failure. */
1867 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1868 if (host_checking && !host_checking_callout)
1871 debug_printf("... callout omitted by default when host testing\n"
1872 "(Use -bhc if you want the callouts to happen.)\n");
1877 deliver_set_expansions(addr);
1879 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1880 callout_connect, options, se_mailfrom, pm_mailfrom);
1885 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1886 "transport provided a host list\n");
1891 /* Otherwise, any failure is a routing failure */
1893 else *failure_ptr = US"route";
1895 /* A router may return REROUTED if it has set up a child address as a result
1896 of a change of domain name (typically from widening). In this case we always
1897 want to continue to verify the new child. */
1899 if (rc == REROUTED) continue;
1901 /* Handle hard failures */
1908 address_item *p = addr->parent;
1910 respond_printf(f, "%s%s %s", ko_prefix,
1911 full_info ? addr->address : address,
1912 address_test_mode ? "is undeliverable" : "failed to verify");
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);
1921 /* Show parents iff doing full info */
1923 if (full_info) while (p)
1925 respond_printf(f, "%s\n <-- %s", cr, p->address);
1928 respond_printf(f, "%s\n", cr);
1930 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1934 yield = copy_error(vaddr, addr, FAIL);
1942 else if (rc == DEFER)
1947 address_item *p = addr->parent;
1948 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1949 full_info? addr->address : address);
1950 if (!expn && admin_user)
1952 if (addr->basic_errno > 0)
1953 respond_printf(f, ": %s", strerror(addr->basic_errno));
1955 respond_printf(f, ": %s", addr->message);
1956 else if (addr->basic_errno <= 0)
1957 respond_printf(f, ": unknown error");
1960 /* Show parents iff doing full info */
1962 if (full_info) while (p)
1964 respond_printf(f, "%s\n <-- %s", cr, p->address);
1967 respond_printf(f, "%s\n", cr);
1969 cancel_cutthrough_connection(TRUE, US"routing soft fail");
1973 yield = copy_error(vaddr, addr, DEFER);
1976 if (yield == OK) yield = DEFER;
1979 /* If we are handling EXPN, we do not want to continue to route beyond
1980 the top level (whose address is in "address"). */
1984 uschar *ok_prefix = US"250-";
1987 if (!addr_local && !addr_remote)
1988 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1990 respond_printf(f, "250 <%s>\r\n", address);
1994 address_item *addr2 = addr_new;
1995 addr_new = addr2->next;
1996 if (!addr_new) ok_prefix = US"250 ";
1997 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2003 /* Successful routing other than EXPN. */
2007 /* Handle successful routing when short info wanted. Otherwise continue for
2008 other (generated) addresses. Short info is the operational case. Full info
2009 can be requested only when debug_selector != 0 and a file is supplied.
2011 There is a conflict between the use of aliasing as an alternate email
2012 address, and as a sort of mailing list. If an alias turns the incoming
2013 address into just one address (e.g. J.Caesar->jc44) you may well want to
2014 carry on verifying the generated address to ensure it is valid when
2015 checking incoming mail. If aliasing generates multiple addresses, you
2016 probably don't want to do this. Exim therefore treats the generation of
2017 just a single new address as a special case, and continues on to verify the
2018 generated address. */
2020 if ( !full_info /* Stop if short info wanted AND */
2021 && ( ( !addr_new /* No new address OR */
2022 || addr_new->next /* More than one new address OR */
2023 || testflag(addr_new, af_pfr) /* New address is pfr */
2026 ( addr_new /* At least one new address AND */
2027 && success_on_redirect /* success_on_redirect is set */
2031 if (f) fprintf(f, "%s %s\n",
2032 address, address_test_mode ? "is deliverable" : "verified");
2034 /* If we have carried on to verify a child address, we want the value
2035 of $address_data to be that of the child */
2037 vaddr->prop.address_data = addr->prop.address_data;
2039 /* If stopped because more than one new address, cannot cutthrough */
2041 if (addr_new && addr_new->next)
2042 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2048 } /* Loop for generated addresses */
2050 /* Display the full results of the successful routing, including any generated
2051 addresses. Control gets here only when full_info is set, which requires f not
2052 to be NULL, and this occurs only when a top-level verify is called with the
2053 debugging switch on.
2055 If there are no local and no remote addresses, and there were no pipes, files,
2056 or autoreplies, and there were no errors or deferments, the message is to be
2057 discarded, usually because of the use of :blackhole: in an alias file. */
2059 if (allok && !addr_local && !addr_remote)
2061 fprintf(f, "mail to %s is discarded\n", address);
2065 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2068 address_item *addr = addr_list;
2069 address_item *p = addr->parent;
2070 transport_instance * tp = addr->transport;
2072 addr_list = addr->next;
2074 fprintf(f, "%s", CS addr->address);
2075 #ifdef EXPERIMENTAL_SRS
2076 if(addr->prop.srs_sender)
2077 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2080 /* If the address is a duplicate, show something about it. */
2082 if (!testflag(addr, af_pfr))
2085 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2086 fprintf(f, " [duplicate, would not be delivered]");
2087 else tree_add_duplicate(addr->unique, addr);
2090 /* Now show its parents */
2092 for (p = addr->parent; p; p = p->parent)
2093 fprintf(f, "\n <-- %s", p->address);
2096 /* Show router, and transport */
2098 fprintf(f, "router = %s, transport = %s\n",
2099 addr->router->name, tp ? tp->name : US"unset");
2101 /* Show any hosts that are set up by a router unless the transport
2102 is going to override them; fiddle a bit to get a nice format. */
2104 if (addr->host_list && tp && !tp->overrides_hosts)
2109 for (h = addr->host_list; h; h = h->next)
2110 { /* get max lengths of host names, addrs */
2111 int len = Ustrlen(h->name);
2112 if (len > maxlen) maxlen = len;
2113 len = h->address ? Ustrlen(h->address) : 7;
2114 if (len > maxaddlen) maxaddlen = len;
2116 for (h = addr->host_list; h; h = h->next)
2118 fprintf(f, " host %-*s ", maxlen, h->name);
2121 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2122 else if (tp->info->local)
2123 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2125 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2127 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2128 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2129 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2130 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2136 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2137 the -bv or -bt case). */
2141 tls_modify_variables(&tls_in);
2149 /*************************************************
2150 * Check headers for syntax errors *
2151 *************************************************/
2153 /* This function checks those header lines that contain addresses, and verifies
2154 that all the addresses therein are syntactially correct.
2157 msgptr where to put an error message
2164 verify_check_headers(uschar **msgptr)
2170 for (h = header_list; h != NULL && yield == OK; h = h->next)
2172 if (h->type != htype_from &&
2173 h->type != htype_reply_to &&
2174 h->type != htype_sender &&
2175 h->type != htype_to &&
2176 h->type != htype_cc &&
2177 h->type != htype_bcc)
2180 colon = Ustrchr(h->text, ':');
2182 while (isspace(*s)) s++;
2184 /* Loop for multiple addresses in the header, enabling group syntax. Note
2185 that we have to reset this after the header has been scanned. */
2187 parse_allow_group = TRUE;
2191 uschar *ss = parse_find_address_end(s, FALSE);
2192 uschar *recipient, *errmess;
2193 int terminator = *ss;
2194 int start, end, domain;
2196 /* Temporarily terminate the string at this point, and extract the
2197 operative address within, allowing group syntax. */
2200 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2203 /* Permit an unqualified address only if the message is local, or if the
2204 sending host is configured to be permitted to send them. */
2206 if (recipient != NULL && domain == 0)
2208 if (h->type == htype_from || h->type == htype_sender)
2210 if (!allow_unqualified_sender) recipient = NULL;
2214 if (!allow_unqualified_recipient) recipient = NULL;
2216 if (recipient == NULL) errmess = US"unqualified address not permitted";
2219 /* It's an error if no address could be extracted, except for the special
2220 case of an empty address. */
2222 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2224 uschar *verb = US"is";
2229 /* Arrange not to include any white space at the end in the
2230 error message or the header name. */
2232 while (t > s && isspace(t[-1])) t--;
2233 while (tt > h->text && isspace(tt[-1])) tt--;
2235 /* Add the address that failed to the error message, since in a
2236 header with very many addresses it is sometimes hard to spot
2237 which one is at fault. However, limit the amount of address to
2238 quote - cases have been seen where, for example, a missing double
2239 quote in a humungous To: header creates an "address" that is longer
2240 than string_sprintf can handle. */
2249 /* deconst cast ok as we're passing a non-const to string_printing() */
2250 *msgptr = US string_printing(
2251 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2252 errmess, tt - h->text, h->text, verb, len, s));
2255 break; /* Out of address loop */
2258 /* Advance to the next address */
2260 s = ss + (terminator? 1:0);
2261 while (isspace(*s)) s++;
2262 } /* Next address */
2264 parse_allow_group = FALSE;
2265 parse_found_group = FALSE;
2266 } /* Next header unless yield has been set FALSE */
2272 /*************************************************
2273 * Check header names for 8-bit characters *
2274 *************************************************/
2276 /* This function checks for invalid characters in header names. See
2277 RFC 5322, 2.2. and RFC 6532, 3.
2280 msgptr where to put an error message
2287 verify_check_header_names_ascii(uschar **msgptr)
2292 for (h = header_list; h; h = h->next)
2294 colon = Ustrchr(h->text, ':');
2295 for(s = h->text; s < colon; s++)
2296 if ((*s < 33) || (*s > 126))
2298 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2299 colon - h->text, h->text);
2306 /*************************************************
2307 * Check for blind recipients *
2308 *************************************************/
2310 /* This function checks that every (envelope) recipient is mentioned in either
2311 the To: or Cc: header lines, thus detecting blind carbon copies.
2313 There are two ways of scanning that could be used: either scan the header lines
2314 and tick off the recipients, or scan the recipients and check the header lines.
2315 The original proposed patch did the former, but I have chosen to do the latter,
2316 because (a) it requires no memory and (b) will use fewer resources when there
2317 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2320 Returns: OK if there are no blind recipients
2321 FAIL if there is at least one blind recipient
2325 verify_check_notblind(void)
2328 for (i = 0; i < recipients_count; i++)
2332 uschar *address = recipients_list[i].address;
2334 for (h = header_list; !found && h != NULL; h = h->next)
2338 if (h->type != htype_to && h->type != htype_cc) continue;
2340 colon = Ustrchr(h->text, ':');
2342 while (isspace(*s)) s++;
2344 /* Loop for multiple addresses in the header, enabling group syntax. Note
2345 that we have to reset this after the header has been scanned. */
2347 parse_allow_group = TRUE;
2351 uschar *ss = parse_find_address_end(s, FALSE);
2352 uschar *recipient,*errmess;
2353 int terminator = *ss;
2354 int start, end, domain;
2356 /* Temporarily terminate the string at this point, and extract the
2357 operative address within, allowing group syntax. */
2360 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2363 /* If we found a valid recipient that has a domain, compare it with the
2364 envelope recipient. Local parts are compared case-sensitively, domains
2365 case-insensitively. By comparing from the start with length "domain", we
2366 include the "@" at the end, which ensures that we are comparing the whole
2367 local part of each address. */
2369 if (recipient != NULL && domain != 0)
2371 found = Ustrncmp(recipient, address, domain) == 0 &&
2372 strcmpic(recipient + domain, address + domain) == 0;
2376 /* Advance to the next address */
2378 s = ss + (terminator? 1:0);
2379 while (isspace(*s)) s++;
2380 } /* Next address */
2382 parse_allow_group = FALSE;
2383 parse_found_group = FALSE;
2384 } /* Next header (if found is false) */
2386 if (!found) return FAIL;
2387 } /* Next recipient */
2394 /*************************************************
2395 * Find if verified sender *
2396 *************************************************/
2398 /* Usually, just a single address is verified as the sender of the message.
2399 However, Exim can be made to verify other addresses as well (often related in
2400 some way), and this is useful in some environments. There may therefore be a
2401 chain of such addresses that have previously been tested. This function finds
2402 whether a given address is on the chain.
2404 Arguments: the address to be verified
2405 Returns: pointer to an address item, or NULL
2409 verify_checked_sender(uschar *sender)
2412 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2413 if (Ustrcmp(sender, addr->address) == 0) break;
2421 /*************************************************
2422 * Get valid header address *
2423 *************************************************/
2425 /* Scan the originator headers of the message, looking for an address that
2426 verifies successfully. RFC 822 says:
2428 o The "Sender" field mailbox should be sent notices of
2429 any problems in transport or delivery of the original
2430 messages. If there is no "Sender" field, then the
2431 "From" field mailbox should be used.
2433 o If the "Reply-To" field exists, then the reply should
2434 go to the addresses indicated in that field and not to
2435 the address(es) indicated in the "From" field.
2437 So we check a Sender field if there is one, else a Reply_to field, else a From
2438 field. As some strange messages may have more than one of these fields,
2439 especially if they are resent- fields, check all of them if there is more than
2443 user_msgptr points to where to put a user error message
2444 log_msgptr points to where to put a log error message
2445 callout timeout for callout check (passed to verify_address())
2446 callout_overall overall callout timeout (ditto)
2447 callout_connect connect callout timeout (ditto)
2448 se_mailfrom mailfrom for verify; NULL => ""
2449 pm_mailfrom sender for pm callout check (passed to verify_address())
2450 options callout options (passed to verify_address())
2451 verrno where to put the address basic_errno
2453 If log_msgptr is set to something without setting user_msgptr, the caller
2454 normally uses log_msgptr for both things.
2456 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2457 FAIL is given if no appropriate headers are found
2461 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2462 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2463 uschar *pm_mailfrom, int options, int *verrno)
2465 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2470 for (i = 0; i < 3 && !done; i++)
2473 for (h = header_list; h != NULL && !done; h = h->next)
2475 int terminator, new_ok;
2476 uschar *s, *ss, *endname;
2478 if (h->type != header_types[i]) continue;
2479 s = endname = Ustrchr(h->text, ':') + 1;
2481 /* Scan the addresses in the header, enabling group syntax. Note that we
2482 have to reset this after the header has been scanned. */
2484 parse_allow_group = TRUE;
2488 address_item *vaddr;
2490 while (isspace(*s) || *s == ',') s++;
2491 if (*s == 0) break; /* End of header */
2493 ss = parse_find_address_end(s, FALSE);
2495 /* The terminator is a comma or end of header, but there may be white
2496 space preceding it (including newline for the last address). Move back
2497 past any white space so we can check against any cached envelope sender
2498 address verifications. */
2500 while (isspace(ss[-1])) ss--;
2504 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2505 (int)(endname - h->text), h->text, s);
2507 /* See if we have already verified this address as an envelope sender,
2508 and if so, use the previous answer. */
2510 vaddr = verify_checked_sender(s);
2512 if (vaddr != NULL && /* Previously checked */
2513 (callout <= 0 || /* No callout needed; OR */
2514 vaddr->special_action > 256)) /* Callout was done */
2516 new_ok = vaddr->special_action & 255;
2517 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2518 *ss = terminator; /* Restore shortened string */
2521 /* Otherwise we run the verification now. We must restore the shortened
2522 string before running the verification, so the headers are correct, in
2523 case there is any rewriting. */
2527 int start, end, domain;
2528 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2533 /* If we found an empty address, just carry on with the next one, but
2534 kill the message. */
2536 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2543 /* If verification failed because of a syntax error, fail this
2544 function, and ensure that the failing address gets added to the error
2547 if (address == NULL)
2550 while (ss > s && isspace(ss[-1])) ss--;
2551 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2552 "scanning for sender: %s in \"%.*s\"",
2553 endname - h->text, h->text, *log_msgptr, ss - s, s);
2559 /* Else go ahead with the sender verification. But it isn't *the*
2560 sender of the message, so set vopt_fake_sender to stop sender_address
2561 being replaced after rewriting or qualification. */
2565 vaddr = deliver_make_addr(address, FALSE);
2566 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2567 callout, callout_overall, callout_connect, se_mailfrom,
2572 /* We now have the result, either newly found, or cached. If we are
2573 giving out error details, set a specific user error. This means that the
2574 last of these will be returned to the user if all three fail. We do not
2575 set a log message - the generic one below will be used. */
2579 *verrno = vaddr->basic_errno;
2580 if (smtp_return_error_details)
2582 *user_msgptr = string_sprintf("Rejected after DATA: "
2583 "could not verify \"%.*s\" header address\n%s: %s",
2584 endname - h->text, h->text, vaddr->address, vaddr->message);
2588 /* Success or defer */
2597 if (new_ok == DEFER) yield = DEFER;
2599 /* Move on to any more addresses in the header */
2602 } /* Next address */
2604 parse_allow_group = FALSE;
2605 parse_found_group = FALSE;
2606 } /* Next header, unless done */
2607 } /* Next header type unless done */
2609 if (yield == FAIL && *log_msgptr == NULL)
2610 *log_msgptr = US"there is no valid sender in any header line";
2612 if (yield == DEFER && *log_msgptr == NULL)
2613 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2621 /*************************************************
2622 * Get RFC 1413 identification *
2623 *************************************************/
2625 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2626 the timeout is set to zero, then the query is not done. There may also be lists
2627 of hosts and nets which are exempt. To guard against malefactors sending
2628 non-printing characters which could, for example, disrupt a message's headers,
2629 make sure the string consists of printing characters only.
2632 port the port to connect to; usually this is IDENT_PORT (113), but when
2633 running in the test harness with -bh a different value is used.
2637 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2641 verify_get_ident(int port)
2643 int sock, host_af, qlen;
2644 int received_sender_port, received_interface_port, n;
2646 uschar buffer[2048];
2648 /* Default is no ident. Check whether we want to do an ident check for this
2651 sender_ident = NULL;
2652 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2655 DEBUG(D_ident) debug_printf("doing ident callback\n");
2657 /* Set up a connection to the ident port of the remote host. Bind the local end
2658 to the incoming interface address. If the sender host address is an IPv6
2659 address, the incoming interface address will also be IPv6. */
2661 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2662 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2664 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2666 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2671 if (ip_connect(sock, host_af, sender_host_address, port,
2672 rfc1413_query_timeout, TRUE) < 0)
2674 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2675 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2676 sender_host_address);
2678 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2679 sender_host_address, strerror(errno));
2683 /* Construct and send the query. */
2685 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2686 qlen = Ustrlen(buffer);
2687 if (send(sock, buffer, qlen, 0) < 0)
2689 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2693 /* Read a response line. We put it into the rest of the buffer, using several
2694 recv() calls if necessary. */
2702 int size = sizeof(buffer) - (p - buffer);
2704 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2705 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2706 if (count <= 0) goto END_OFF; /* Read error or EOF */
2708 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2709 generous, and accept a plain \n terminator as well. The only illegal
2712 for (pp = p; pp < p + count; pp++)
2714 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2717 if (pp[-1] == '\r') pp--;
2719 goto GOT_DATA; /* Break out of both loops */
2723 /* Reached the end of the data without finding \n. Let the loop continue to
2724 read some more, if there is room. */
2731 /* We have received a line of data. Check it carefully. It must start with the
2732 same two port numbers that we sent, followed by data as defined by the RFC. For
2735 12345 , 25 : USERID : UNIX :root
2737 However, the amount of white space may be different to what we sent. In the
2738 "osname" field there may be several sub-fields, comma separated. The data we
2739 actually want to save follows the third colon. Some systems put leading spaces
2740 in it - we discard those. */
2742 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2743 &received_interface_port, &n) != 2 ||
2744 received_sender_port != sender_host_port ||
2745 received_interface_port != interface_port)
2748 p = buffer + qlen + n;
2749 while(isspace(*p)) p++;
2750 if (*p++ != ':') goto END_OFF;
2751 while(isspace(*p)) p++;
2752 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2754 while(isspace(*p)) p++;
2755 if (*p++ != ':') goto END_OFF;
2756 while (*p != 0 && *p != ':') p++;
2757 if (*p++ == 0) goto END_OFF;
2758 while(isspace(*p)) p++;
2759 if (*p == 0) goto END_OFF;
2761 /* The rest of the line is the data we want. We turn it into printing
2762 characters when we save it, so that it cannot mess up the format of any logging
2763 or Received: lines into which it gets inserted. We keep a maximum of 127
2764 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2766 sender_ident = US string_printing(string_copyn(p, 127));
2767 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2777 /*************************************************
2778 * Match host to a single host-list item *
2779 *************************************************/
2781 /* This function compares a host (name or address) against a single item
2782 from a host list. The host name gets looked up if it is needed and is not
2783 already known. The function is called from verify_check_this_host() via
2784 match_check_list(), which is why most of its arguments are in a single block.
2787 arg the argument block (see below)
2788 ss the host-list item
2789 valueptr where to pass back looked up data, or NULL
2790 error for error message when returning ERROR
2793 host_name (a) the host name, or
2794 (b) NULL, implying use sender_host_name and
2795 sender_host_aliases, looking them up if required, or
2796 (c) the empty string, meaning that only IP address matches
2798 host_address the host address
2799 host_ipv4 the IPv4 address taken from an IPv6 one
2803 DEFER lookup deferred
2804 ERROR (a) failed to find the host name or IP address, or
2805 (b) unknown lookup type specified, or
2806 (c) host name encountered when only IP addresses are
2811 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2813 check_host_block *cb = (check_host_block *)arg;
2816 BOOL iplookup = FALSE;
2817 BOOL isquery = FALSE;
2818 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2823 /* Optimize for the special case when the pattern is "*". */
2825 if (*ss == '*' && ss[1] == 0) return OK;
2827 /* If the pattern is empty, it matches only in the case when there is no host -
2828 this can occur in ACL checking for SMTP input using the -bs option. In this
2829 situation, the host address is the empty string. */
2831 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2832 if (*ss == 0) return FAIL;
2834 /* If the pattern is precisely "@" then match against the primary host name,
2835 provided that host name matching is permitted; if it's "@[]" match against the
2836 local host's IP addresses. */
2842 if (isiponly) return ERROR;
2843 ss = primary_hostname;
2845 else if (Ustrcmp(ss, "@[]") == 0)
2847 ip_address_item *ip;
2848 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2849 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2854 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2855 a (possibly masked) comparison with the current IP address. */
2857 if (string_is_ip_address(ss, &maskoffset) != 0)
2858 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2860 /* The pattern is not an IP address. A common error that people make is to omit
2861 one component of an IPv4 address, either by accident, or believing that, for
2862 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,
2863 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2864 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2865 ancient specification.) To aid in debugging these cases, we give a specific
2866 error if the pattern contains only digits and dots or contains a slash preceded
2867 only by digits and dots (a slash at the start indicates a file name and of
2868 course slashes may be present in lookups, but not preceded only by digits and
2871 for (t = ss; isdigit(*t) || *t == '.'; t++);
2872 if (*t == 0 || (*t == '/' && t != ss))
2874 *error = US"malformed IPv4 address or address mask";
2878 /* See if there is a semicolon in the pattern */
2880 semicolon = Ustrchr(ss, ';');
2882 /* If we are doing an IP address only match, then all lookups must be IP
2883 address lookups, even if there is no "net-". */
2887 iplookup = semicolon != NULL;
2890 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2891 a lookup on a masked IP network, in textual form. We obey this code even if we
2892 have already set iplookup, so as to skip over the "net-" prefix and to set the
2893 mask length. The net- stuff really only applies to single-key lookups where the
2894 key is implicit. For query-style lookups the key is specified in the query.
2895 From release 4.30, the use of net- for query style is no longer needed, but we
2896 retain it for backward compatibility. */
2898 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2901 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2902 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2903 iplookup = (*t++ == '-');
2907 /* Do the IP address lookup if that is indeed what we have */
2915 uschar *filename, *key, *result;
2918 /* Find the search type */
2920 search_type = search_findtype(t, semicolon - t);
2922 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2923 search_error_message);
2925 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2926 is no file name, and the "key" is just the query. For query-style with a file
2927 name, we have to fish the file off the start of the query. For a single-key
2928 lookup, the key is the current IP address, masked appropriately, and
2929 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2930 dot separators instead of colons, except when the lookup type is "iplsearch".
2933 if (mac_islookup(search_type, lookup_absfilequery))
2935 filename = semicolon + 1;
2937 while (*key != 0 && !isspace(*key)) key++;
2938 filename = string_copyn(filename, key - filename);
2939 while (isspace(*key)) key++;
2941 else if (mac_islookup(search_type, lookup_querystyle))
2944 key = semicolon + 1;
2946 else /* Single-key style */
2948 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2950 insize = host_aton(cb->host_address, incoming);
2951 host_mask(insize, incoming, mlen);
2952 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2954 filename = semicolon + 1;
2957 /* Now do the actual lookup; note that there is no search_close() because
2958 of the caching arrangements. */
2960 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2961 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2963 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2964 if (valueptr != NULL) *valueptr = result;
2965 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2968 /* The pattern is not an IP address or network reference of any kind. That is,
2969 it is a host name pattern. If this is an IP only match, there's an error in the
2974 *error = US"cannot match host name in match_ip list";
2978 /* Check the characters of the pattern to see if they comprise only letters,
2979 digits, full stops, and hyphens (the constituents of domain names). Allow
2980 underscores, as they are all too commonly found. Sigh. Also, if
2981 allow_utf8_domains is set, allow top-bit characters. */
2983 for (t = ss; *t != 0; t++)
2984 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2985 (!allow_utf8_domains || *t < 128)) break;
2987 /* If the pattern is a complete domain name, with no fancy characters, look up
2988 its IP address and match against that. Note that a multi-homed host will add
2989 items to the chain. */
3000 /* Using byname rather than bydns here means we cannot determine dnssec
3001 status. On the other hand it is unclear how that could be either
3002 propagated up or enforced. */
3004 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3005 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3008 for (hh = &h; hh != NULL; hh = hh->next)
3010 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3014 if (rc == HOST_FIND_AGAIN) return DEFER;
3015 *error = string_sprintf("failed to find IP address for %s", ss);
3019 /* Almost all subsequent comparisons require the host name, and can be done
3020 using the general string matching function. When this function is called for
3021 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3022 must use sender_host_name and its aliases, looking them up if necessary. */
3024 if (cb->host_name != NULL) /* Explicit host name given */
3025 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3028 /* Host name not given; in principle we need the sender host name and its
3029 aliases. However, for query-style lookups, we do not need the name if the
3030 query does not contain $sender_host_name. From release 4.23, a reference to
3031 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3034 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3036 const uschar *affix;
3037 int partial, affixlen, starflags, id;
3040 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3043 if (id < 0) /* Unknown lookup type */
3045 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3046 search_error_message, ss);
3049 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3054 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3057 case DEFER: return DEFER;
3058 default: return FAIL;
3062 /* Not a query-style lookup; must ensure the host name is present, and then we
3063 do a check on the name and all its aliases. */
3065 if (sender_host_name == NULL)
3067 HDEBUG(D_host_lookup)
3068 debug_printf("sender host name required, to match against %s\n", ss);
3069 if (host_lookup_failed || host_name_lookup() != OK)
3071 *error = string_sprintf("failed to find host name for %s",
3072 sender_host_address);;
3075 host_build_sender_fullhost();
3078 /* Match on the sender host name, using the general matching function */
3080 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3084 case DEFER: return DEFER;
3087 /* If there are aliases, try matching on them. */
3089 aliases = sender_host_aliases;
3090 while (*aliases != NULL)
3092 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3095 case DEFER: return DEFER;
3104 /*************************************************
3105 * Check a specific host matches a host list *
3106 *************************************************/
3108 /* This function is passed a host list containing items in a number of
3109 different formats and the identity of a host. Its job is to determine whether
3110 the given host is in the set of hosts defined by the list. The host name is
3111 passed as a pointer so that it can be looked up if needed and not already
3112 known. This is commonly the case when called from verify_check_host() to check
3113 an incoming connection. When called from elsewhere the host name should usually
3116 This function is now just a front end to match_check_list(), which runs common
3117 code for scanning a list. We pass it the check_host() function to perform a
3121 listptr pointer to the host list
3122 cache_bits pointer to cache for named lists, or NULL
3123 host_name the host name or NULL, implying use sender_host_name and
3124 sender_host_aliases, looking them up if required
3125 host_address the IP address
3126 valueptr if not NULL, data from a lookup is passed back here
3128 Returns: OK if the host is in the defined set
3129 FAIL if the host is not in the defined set,
3130 DEFER if a data lookup deferred (not a host lookup)
3132 If the host name was needed in order to make a comparison, and could not be
3133 determined from the IP address, the result is FAIL unless the item
3134 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3137 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3138 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3141 unsigned int *local_cache_bits = cache_bits;
3142 const uschar *save_host_address = deliver_host_address;
3143 check_host_block cb;
3144 cb.host_name = host_name;
3145 cb.host_address = host_address;
3147 if (valueptr != NULL) *valueptr = NULL;
3149 /* If the host address starts off ::ffff: it is an IPv6 address in
3150 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3153 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3154 host_address + 7 : host_address;
3156 /* During the running of the check, put the IP address into $host_address. In
3157 the case of calls from the smtp transport, it will already be there. However,
3158 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3159 the safe side, any existing setting is preserved, though as I write this
3160 (November 2004) I can't see any cases where it is actually needed. */
3162 deliver_host_address = host_address;
3163 rc = match_check_list(
3164 listptr, /* the list */
3165 0, /* separator character */
3166 &hostlist_anchor, /* anchor pointer */
3167 &local_cache_bits, /* cache pointer */
3168 check_host, /* function for testing */
3169 &cb, /* argument for function */
3170 MCL_HOST, /* type of check */
3171 (host_address == sender_host_address)?
3172 US"host" : host_address, /* text for debugging */
3173 valueptr); /* where to pass back data */
3174 deliver_host_address = save_host_address;
3181 /*************************************************
3182 * Check the given host item matches a list *
3183 *************************************************/
3185 verify_check_given_host(uschar **listptr, host_item *host)
3187 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3190 /*************************************************
3191 * Check the remote host matches a list *
3192 *************************************************/
3194 /* This is a front end to verify_check_this_host(), created because checking
3195 the remote host is a common occurrence. With luck, a good compiler will spot
3196 the tail recursion and optimize it. If there's no host address, this is
3197 command-line SMTP input - check against an empty string for the address.
3200 listptr pointer to the host list
3202 Returns: the yield of verify_check_this_host(),
3203 i.e. OK, FAIL, or DEFER
3207 verify_check_host(uschar **listptr)
3209 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3210 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3217 /*************************************************
3218 * Invert an IP address *
3219 *************************************************/
3221 /* Originally just used for DNS xBL lists, now also used for the
3222 reverse_ip expansion operator.
3225 buffer where to put the answer
3226 address the address to invert
3230 invert_address(uschar *buffer, uschar *address)
3233 uschar *bptr = buffer;
3235 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3236 to the IPv4 part only. */
3238 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3240 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3243 if (host_aton(address, bin) == 1)
3247 for (i = 0; i < 4; i++)
3249 sprintf(CS bptr, "%d.", x & 255);
3250 while (*bptr) bptr++;
3255 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3256 in any DNS black lists, and the format in which they will be looked up is
3257 unknown. This is just a guess. */
3263 for (j = 3; j >= 0; j--)
3266 for (i = 0; i < 8; i++)
3268 sprintf(CS bptr, "%x.", x & 15);
3269 while (*bptr) bptr++;
3276 /* Remove trailing period -- this is needed so that both arbitrary
3277 dnsbl keydomains and inverted addresses may be combined with the
3278 same format string, "%s.%s" */
3285 /*************************************************
3286 * Perform a single dnsbl lookup *
3287 *************************************************/
3289 /* This function is called from verify_check_dnsbl() below. It is also called
3290 recursively from within itself when domain and domain_txt are different
3291 pointers, in order to get the TXT record from the alternate domain.
3294 domain the outer dnsbl domain
3295 domain_txt alternate domain to lookup TXT record on success; when the
3296 same domain is to be used, domain_txt == domain (that is,
3297 the pointers must be identical, not just the text)
3298 keydomain the current keydomain (for debug message)
3299 prepend subdomain to lookup (like keydomain, but
3300 reversed if IP address)
3301 iplist the list of matching IP addresses, or NULL for "any"
3302 bitmask true if bitmask matching is wanted
3303 match_type condition for 'succeed' result
3304 0 => Any RR in iplist (=)
3305 1 => No RR in iplist (!=)
3306 2 => All RRs in iplist (==)
3307 3 => Some RRs not in iplist (!==)
3308 the two bits are defined as MT_NOT and MT_ALL
3309 defer_return what to return for a defer
3311 Returns: OK if lookup succeeded
3316 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3317 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3323 dnsbl_cache_block *cb;
3324 int old_pool = store_pool;
3325 uschar query[256]; /* DNS domain max length */
3327 /* Construct the specific query domainname */
3329 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3331 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3332 "(ignored): %s...", query);
3336 /* Look for this query in the cache. */
3338 if ( (t = tree_search(dnsbl_cache, query))
3339 && (cb = t->data.ptr)->expiry > time(NULL)
3342 /* Previous lookup was cached */
3345 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3348 /* If not cached from a previous lookup, we must do a DNS lookup, and
3349 cache the result in permanent memory. */
3355 store_pool = POOL_PERM;
3359 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3363 { /* Set up a tree entry to cache the lookup */
3364 t = store_get(sizeof(tree_node) + Ustrlen(query));
3365 Ustrcpy(t->name, query);
3366 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3367 (void)tree_insertnode(&dnsbl_cache, t);
3370 /* Do the DNS lookup . */
3372 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3373 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3374 cb->text_set = FALSE;
3378 /* If the lookup succeeded, cache the RHS address. The code allows for
3379 more than one address - this was for complete generality and the possible
3380 use of A6 records. However, A6 records have been reduced to experimental
3381 status (August 2001) and may die out. So they may never get used at all,
3382 let alone in dnsbl records. However, leave the code here, just in case.
3384 Quite apart from one A6 RR generating multiple addresses, there are DNS
3385 lists that return more than one A record, so we must handle multiple
3386 addresses generated in that way as well.
3388 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3389 or some suitably far-future time if none were found. */
3391 if (cb->rc == DNS_SUCCEED)
3394 dns_address **addrp = &(cb->rhs);
3395 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3397 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3399 if (rr->type == T_A)
3401 dns_address *da = dns_address_from_rr(&dnsa, rr);
3405 while (da->next != NULL) da = da->next;
3406 addrp = &(da->next);
3407 if (ttl > rr->ttl) ttl = rr->ttl;
3412 /* If we didn't find any A records, change the return code. This can
3413 happen when there is a CNAME record but there are no A records for what
3416 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3419 cb->expiry = time(NULL)+ttl;
3420 store_pool = old_pool;
3423 /* We now have the result of the DNS lookup, either newly done, or cached
3424 from a previous call. If the lookup succeeded, check against the address
3425 list if there is one. This may be a positive equality list (introduced by
3426 "="), a negative equality list (introduced by "!="), a positive bitmask
3427 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3429 if (cb->rc == DNS_SUCCEED)
3431 dns_address *da = NULL;
3432 uschar *addlist = cb->rhs->address;
3434 /* For A and AAAA records, there may be multiple addresses from multiple
3435 records. For A6 records (currently not expected to be used) there may be
3436 multiple addresses from a single record. */
3438 for (da = cb->rhs->next; da != NULL; da = da->next)
3439 addlist = string_sprintf("%s, %s", addlist, da->address);
3441 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3444 /* Address list check; this can be either for equality, or via a bitmask.
3445 In the latter case, all the bits must match. */
3449 for (da = cb->rhs; da != NULL; da = da->next)
3453 const uschar *ptr = iplist;
3456 /* Handle exact matching */
3460 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3462 if (Ustrcmp(CS da->address, ip) == 0) break;
3466 /* Handle bitmask matching */
3473 /* At present, all known DNS blocking lists use A records, with
3474 IPv4 addresses on the RHS encoding the information they return. I
3475 wonder if this will linger on as the last vestige of IPv4 when IPv6
3476 is ubiquitous? Anyway, for now we use paranoia code to completely
3477 ignore IPv6 addresses. The default mask is 0, which always matches.
3478 We change this only for IPv4 addresses in the list. */
3480 if (host_aton(da->address, address) == 1) mask = address[0];
3482 /* Scan the returned addresses, skipping any that are IPv6 */
3484 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3486 if (host_aton(ip, address) != 1) continue;
3487 if ((address[0] & mask) == address[0]) break;
3493 (a) An IP address in an any ('=') list matched, or
3494 (b) No IP address in an all ('==') list matched
3496 then we're done searching. */
3498 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3501 /* If da == NULL, either
3503 (a) No IP address in an any ('=') list matched, or
3504 (b) An IP address in an all ('==') list didn't match
3506 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3509 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3517 res = US"was no match";
3520 res = US"was an exclude match";
3523 res = US"was an IP address that did not match";
3526 res = US"were no IP addresses that did not match";
3529 debug_printf("=> but we are not accepting this block class because\n");
3530 debug_printf("=> there %s for %s%c%s\n",
3532 ((match_type & MT_ALL) == 0)? "" : "=",
3533 bitmask? '&' : '=', iplist);
3539 /* Either there was no IP list, or the record matched, implying that the
3540 domain is on the list. We now want to find a corresponding TXT record. If an
3541 alternate domain is specified for the TXT record, call this function
3542 recursively to look that up; this has the side effect of re-checking that
3543 there is indeed an A record at the alternate domain. */
3545 if (domain_txt != domain)
3546 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3547 FALSE, match_type, defer_return);
3549 /* If there is no alternate domain, look up a TXT record in the main domain
3550 if it has not previously been cached. */
3554 cb->text_set = TRUE;
3555 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3558 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3560 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3561 if (rr->type == T_TXT) break;
3564 int len = (rr->data)[0];
3565 if (len > 511) len = 127;
3566 store_pool = POOL_PERM;
3567 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3568 store_pool = old_pool;
3573 dnslist_value = addlist;
3574 dnslist_text = cb->text;
3578 /* There was a problem with the DNS lookup */
3580 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3582 log_write(L_dnslist_defer, LOG_MAIN,
3583 "DNS list lookup defer (probably timeout) for %s: %s", query,
3584 (defer_return == OK)? US"assumed in list" :
3585 (defer_return == FAIL)? US"assumed not in list" :
3586 US"returned DEFER");
3587 return defer_return;
3590 /* No entry was found in the DNS; continue for next domain */
3594 debug_printf("DNS lookup for %s failed\n", query);
3595 debug_printf("=> that means %s is not listed at %s\n",
3605 /*************************************************
3606 * Check host against DNS black lists *
3607 *************************************************/
3609 /* This function runs checks against a list of DNS black lists, until one
3610 matches. Each item on the list can be of the form
3612 domain=ip-address/key
3614 The domain is the right-most domain that is used for the query, for example,
3615 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3616 if the DNS lookup returns a matching IP address. Several addresses may be
3617 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3619 If no key is given, what is looked up in the domain is the inverted IP address
3620 of the current client host. If a key is given, it is used to construct the
3621 domain for the lookup. For example:
3623 dsn.rfc-ignorant.org/$sender_address_domain
3625 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3626 then we check for a TXT record for an error message, and if found, save its
3627 value in $dnslist_text. We also cache everything in a tree, to optimize
3630 The TXT record is normally looked up in the same domain as the A record, but
3631 when many lists are combined in a single DNS domain, this will not be a very
3632 specific message. It is possible to specify a different domain for looking up
3633 TXT records; this is given before the main domain, comma-separated. For
3636 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3637 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3639 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3641 Note: an address for testing RBL is 192.203.178.39
3642 Note: an address for testing DUL is 192.203.178.4
3643 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3647 listptr the domain/address/data list
3648 log_msgptr log message on error
3650 Returns: OK successful lookup (i.e. the address is on the list), or
3651 lookup deferred after +include_unknown
3652 FAIL name not found, or no data found for the given type, or
3653 lookup deferred after +exclude_unknown (default)
3654 DEFER lookup failure, if +defer_unknown was set
3658 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3661 int defer_return = FAIL;
3662 const uschar *list = *listptr;
3665 uschar buffer[1024];
3666 uschar revadd[128]; /* Long enough for IPv6 address */
3668 /* Indicate that the inverted IP address is not yet set up */
3672 /* In case this is the first time the DNS resolver is being used. */
3674 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3676 /* Loop through all the domains supplied, until something matches */
3678 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3681 BOOL bitmask = FALSE;
3688 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3690 /* Deal with special values that change the behaviour on defer */
3692 if (domain[0] == '+')
3694 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3695 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3696 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3698 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3703 /* See if there's explicit data to be looked up */
3705 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3707 /* See if there's a list of addresses supplied after the domain name. This is
3708 introduced by an = or a & character; if preceded by = we require all matches
3709 and if preceded by ! we invert the result. */
3711 if (!(iplist = Ustrchr(domain, '=')))
3714 iplist = Ustrchr(domain, '&');
3717 if (iplist) /* Found either = or & */
3719 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3721 match_type |= MT_NOT;
3725 *iplist++ = 0; /* Terminate domain, move on */
3727 /* If we found = (bitmask == FALSE), check for == or =& */
3729 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3731 bitmask = *iplist++ == '&';
3732 match_type |= MT_ALL;
3737 /* If there is a comma in the domain, it indicates that a second domain for
3738 looking up TXT records is provided, before the main domain. Otherwise we must
3739 set domain_txt == domain. */
3741 domain_txt = domain;
3742 comma = Ustrchr(domain, ',');
3749 /* Check that what we have left is a sensible domain name. There is no reason
3750 why these domains should in fact use the same syntax as hosts and email
3751 domains, but in practice they seem to. However, there is little point in
3752 actually causing an error here, because that would no doubt hold up incoming
3753 mail. Instead, I'll just log it. */
3755 for (s = domain; *s != 0; s++)
3757 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3759 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3760 "strange characters - is this right?", domain);
3765 /* Check the alternate domain if present */
3767 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3769 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3771 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3772 "strange characters - is this right?", domain_txt);
3777 /* If there is no key string, construct the query by adding the domain name
3778 onto the inverted host address, and perform a single DNS lookup. */
3782 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3784 *log_msgptr = string_sprintf
3785 ("cannot test auto-keyed dnslists condition in %s ACL",
3786 acl_wherenames[where]);
3789 if (sender_host_address == NULL) return FAIL; /* can never match */
3790 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3791 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3792 iplist, bitmask, match_type, defer_return);
3795 dnslist_domain = string_copy(domain_txt);
3796 dnslist_matched = string_copy(sender_host_address);
3797 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3798 sender_host_address, dnslist_domain);
3800 if (rc != FAIL) return rc; /* OK or DEFER */
3803 /* If there is a key string, it can be a list of domains or IP addresses to
3804 be concatenated with the main domain. */
3811 uschar keybuffer[256];
3812 uschar keyrevadd[128];
3814 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3815 sizeof(keybuffer))) != NULL)
3817 uschar *prepend = keydomain;
3819 if (string_is_ip_address(keydomain, NULL) != 0)
3821 invert_address(keyrevadd, keydomain);
3822 prepend = keyrevadd;
3825 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3826 bitmask, match_type, defer_return);
3830 dnslist_domain = string_copy(domain_txt);
3831 dnslist_matched = string_copy(keydomain);
3832 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3833 keydomain, dnslist_domain);
3837 /* If the lookup deferred, remember this fact. We keep trying the rest
3838 of the list to see if we get a useful result, and if we don't, we return
3839 DEFER at the end. */
3841 if (rc == DEFER) defer = TRUE;
3842 } /* continue with next keystring domain/address */
3844 if (defer) return DEFER;
3846 } /* continue with next dnsdb outer domain */
3853 /* End of verify.c */