1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
42 static uschar cutthrough_response(char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 cache_record = dbfn_read_with_length(dbm_file, key, &length);
73 if (cache_record == NULL)
75 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
79 /* We treat a record as "negative" if its result field is not positive, or if
80 it is a domain record and the postmaster field is negative. */
82 negative = cache_record->result != ccache_accept ||
83 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
84 expire = negative? negative_expire : positive_expire;
87 if (now - cache_record->time_stamp > expire)
89 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
93 /* If this is a non-reject domain record, check for the obsolete format version
94 that doesn't have the postmaster and random timestamps, by looking at the
95 length. If so, copy it to a new-style block, replicating the record's
96 timestamp. Then check the additional timestamps. (There's no point wasting
97 effort if connections are rejected.) */
99 if (type[0] == 'd' && cache_record->result != ccache_reject)
101 if (length == sizeof(dbdata_callout_cache_obs))
103 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
104 memcpy(new, cache_record, length);
105 new->postmaster_stamp = new->random_stamp = new->time_stamp;
109 if (now - cache_record->postmaster_stamp > expire)
110 cache_record->postmaster_result = ccache_unknown;
112 if (now - cache_record->random_stamp > expire)
113 cache_record->random_result = ccache_unknown;
116 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
122 /* Check the callout cache.
123 Options * pm_mailfrom may be modified by cache partial results.
125 Return: TRUE if result found
129 cached_callout_lookup(address_item * addr, uschar * address_key,
130 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
131 int * yield, uschar ** failure_ptr,
132 dbdata_callout_cache * new_domain_record, int * old_domain_res)
134 int options = *opt_ptr;
136 open_db *dbm_file = NULL;
138 /* Open the callout cache database, it it exists, for reading only at this
139 stage, unless caching has been disabled. */
141 if (options & vopt_callout_no_cache)
143 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
145 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
147 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
151 /* If a cache database is available see if we can avoid the need to do an
152 actual callout by making use of previously-obtained data. */
154 dbdata_callout_cache_address * cache_address_record;
155 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
156 addr->domain, US"domain",
157 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
159 /* If an unexpired cache record was found for this domain, see if the callout
160 process can be short-circuited. */
164 /* In most cases, if an early command (up to and including MAIL FROM:<>)
165 was rejected, there is no point carrying on. The callout fails. However, if
166 we are doing a recipient verification with use_sender or use_postmaster
167 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
168 will be using a non-empty sender. We have to remember this situation so as
169 not to disturb the cached domain value if this whole verification succeeds
170 (we don't want it turning into "accept"). */
172 *old_domain_res = cache_record->result;
174 if ( cache_record->result == ccache_reject
175 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
177 setflag(addr, af_verify_nsfail);
179 debug_printf("callout cache: domain gave initial rejection, or "
180 "does not accept HELO or MAIL FROM:<>\n");
181 setflag(addr, af_verify_nsfail);
182 addr->user_message = US"(result of an earlier callout reused).";
184 *failure_ptr = US"mail";
185 dbfn_close(dbm_file);
189 /* If a previous check on a "random" local part was accepted, we assume
190 that the server does not do any checking on local parts. There is therefore
191 no point in doing the callout, because it will always be successful. If a
192 random check previously failed, arrange not to do it again, but preserve
193 the data in the new record. If a random check is required but hasn't been
194 done, skip the remaining cache processing. */
196 if (options & vopt_callout_random) switch(cache_record->random_result)
200 debug_printf("callout cache: domain accepts random addresses\n");
201 dbfn_close(dbm_file);
202 return TRUE; /* Default yield is OK */
206 debug_printf("callout cache: domain rejects random addresses\n");
207 *opt_ptr = options & ~vopt_callout_random;
208 new_domain_record->random_result = ccache_reject;
209 new_domain_record->random_stamp = cache_record->random_stamp;
214 debug_printf("callout cache: need to check random address handling "
215 "(not cached or cache expired)\n");
216 dbfn_close(dbm_file);
220 /* If a postmaster check is requested, but there was a previous failure,
221 there is again no point in carrying on. If a postmaster check is required,
222 but has not been done before, we are going to have to do a callout, so skip
223 remaining cache processing. */
227 if (cache_record->postmaster_result == ccache_reject)
229 setflag(addr, af_verify_pmfail);
231 debug_printf("callout cache: domain does not accept "
232 "RCPT TO:<postmaster@domain>\n");
234 *failure_ptr = US"postmaster";
235 setflag(addr, af_verify_pmfail);
236 addr->user_message = US"(result of earlier verification reused).";
237 dbfn_close(dbm_file);
240 if (cache_record->postmaster_result == ccache_unknown)
243 debug_printf("callout cache: need to check RCPT "
244 "TO:<postmaster@domain> (not cached or cache expired)\n");
245 dbfn_close(dbm_file);
249 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
250 postmaster check if the address itself has to be checked. Also ensure
251 that the value in the cache record is preserved (with its old timestamp).
254 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
255 "TO:<postmaster@domain>\n");
257 new_domain_record->postmaster_result = ccache_accept;
258 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
262 /* We can't give a result based on information about the domain. See if there
263 is an unexpired cache record for this specific address (combined with the
264 sender address if we are doing a recipient callout with a non-empty sender).
267 if (!(cache_address_record = (dbdata_callout_cache_address *)
268 get_callout_cache_record(dbm_file, address_key, US"address",
269 callout_cache_positive_expire, callout_cache_negative_expire)))
271 dbfn_close(dbm_file);
275 if (cache_address_record->result == ccache_accept)
278 debug_printf("callout cache: address record is positive\n");
283 debug_printf("callout cache: address record is negative\n");
284 addr->user_message = US"Previous (cached) callout verification failure";
285 *failure_ptr = US"recipient";
289 /* Close the cache database while we actually do the callout for real. */
291 dbfn_close(dbm_file);
298 /* Write results to callout cache
301 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
302 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
305 open_db *dbm_file = NULL;
307 /* If we get here with done == TRUE, a successful callout happened, and yield
308 will be set OK or FAIL according to the response to the RCPT command.
309 Otherwise, we looped through the hosts but couldn't complete the business.
310 However, there may be domain-specific information to cache in both cases.
312 The value of the result field in the new_domain record is ccache_unknown if
313 there was an error before or with MAIL FROM:, and errno was not zero,
314 implying some kind of I/O error. We don't want to write the cache in that case.
315 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
317 if (dom_rec->result != ccache_unknown)
318 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
320 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
324 (void)dbfn_write(dbm_file, domain, dom_rec,
325 (int)sizeof(dbdata_callout_cache));
326 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
327 " result=%d postmaster=%d random=%d\n",
330 dom_rec->postmaster_result,
331 dom_rec->random_result);
334 /* If a definite result was obtained for the callout, cache it unless caching
337 if (done && addr_rec->result != ccache_unknown)
340 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
343 HDEBUG(D_verify) debug_printf("no callout cache available\n");
347 (void)dbfn_write(dbm_file, address_key, addr_rec,
348 (int)sizeof(dbdata_callout_cache_address));
349 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
350 addr_rec->result == ccache_accept ? "positive" : "negative",
355 if (dbm_file) dbfn_close(dbm_file);
359 /*************************************************
360 * Do callout verification for an address *
361 *************************************************/
363 /* This function is called from verify_address() when the address has routed to
364 a host list, and a callout has been requested. Callouts are expensive; that is
365 why a cache is used to improve the efficiency.
368 addr the address that's been routed
369 host_list the list of hosts to try
370 tf the transport feedback block
372 ifstring "interface" option from transport, or NULL
373 portstring "port" option from transport, or NULL
374 protocolstring "protocol" option from transport, or NULL
375 callout the per-command callout timeout
376 callout_overall the overall callout timeout (if < 0 use 4*callout)
377 callout_connect the callout connection timeout (if < 0 use callout)
378 options the verification options - these bits are used:
379 vopt_is_recipient => this is a recipient address
380 vopt_callout_no_cache => don't use callout cache
381 vopt_callout_fullpm => if postmaster check, do full one
382 vopt_callout_random => do the "random" thing
383 vopt_callout_recipsender => use real sender for recipient
384 vopt_callout_recippmaster => use postmaster for recipient
385 se_mailfrom MAIL FROM address for sender verify; NULL => ""
386 pm_mailfrom if non-NULL, do the postmaster check with this sender
388 Returns: OK/FAIL/DEFER
392 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
393 int callout, int callout_overall, int callout_connect, int options,
394 uschar *se_mailfrom, uschar *pm_mailfrom)
397 int old_domain_cache_result = ccache_accept;
400 uschar *from_address;
401 uschar *random_local_part = NULL;
402 const uschar *save_deliver_domain = deliver_domain;
403 uschar **failure_ptr = options & vopt_is_recipient
404 ? &recipient_verify_failure : &sender_verify_failure;
405 dbdata_callout_cache new_domain_record;
406 dbdata_callout_cache_address new_address_record;
408 time_t callout_start_time;
410 new_domain_record.result = ccache_unknown;
411 new_domain_record.postmaster_result = ccache_unknown;
412 new_domain_record.random_result = ccache_unknown;
414 memset(&new_address_record, 0, sizeof(new_address_record));
416 /* For a recipient callout, the key used for the address cache record must
417 include the sender address if we are using the real sender in the callout,
418 because that may influence the result of the callout. */
420 if (options & vopt_is_recipient)
421 if (options & vopt_callout_recipsender)
423 from_address = sender_address;
424 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
425 if (cutthrough.delivery) options |= vopt_callout_no_cache;
427 else if (options & vopt_callout_recippmaster)
429 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
430 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
431 qualify_domain_sender);
436 address_key = addr->address;
439 /* For a sender callout, we must adjust the key if the mailfrom address is not
444 from_address = se_mailfrom ? se_mailfrom : US"";
445 address_key = *from_address
446 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
449 if (cached_callout_lookup(addr, address_key, from_address,
450 &options, &pm_mailfrom, &yield, failure_ptr,
451 &new_domain_record, &old_domain_cache_result))
454 if (!addr->transport)
456 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
458 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
459 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
460 addr->transport->name, addr->transport->driver_name);
463 smtp_transport_options_block *ob =
464 (smtp_transport_options_block *)addr->transport->options_block;
466 /* The information wasn't available in the cache, so we have to do a real
467 callout and save the result in the cache for next time, unless no_cache is set,
468 or unless we have a previously cached negative random result. If we are to test
469 with a random local part, ensure that such a local part is available. If not,
470 log the fact, but carry on without randomising. */
472 if (options & vopt_callout_random && callout_random_local_part)
473 if (!(random_local_part = expand_string(callout_random_local_part)))
474 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
475 "callout_random_local_part: %s", expand_string_message);
477 /* Default the connect and overall callout timeouts if not set, and record the
478 time we are starting so that we can enforce it. */
480 if (callout_overall < 0) callout_overall = 4 * callout;
481 if (callout_connect < 0) callout_connect = callout;
482 callout_start_time = time(NULL);
484 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
485 output because a callout might take some time. When PIPELINING is active and
486 there are many recipients, the total time for doing lots of callouts can add up
487 and cause the client to time out. So in this case we forgo the PIPELINING
490 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
492 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
493 and we are holding a cutthrough conn open, we can just append the rcpt to
494 that conn for verification purposes (and later delivery also). Simplest
495 coding means skipping this whole loop and doing the append separately.
497 We will need to remember it has been appended so that rcpt-acl tail code
498 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
501 /* Can we re-use an open cutthrough connection? */
502 if ( cutthrough.fd >= 0
503 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
504 == vopt_callout_recipsender
505 && !random_local_part
509 if (addr->transport == cutthrough.addr.transport)
510 for (host = host_list; host; host = host->next)
511 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
514 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
517 deliver_host = host->name;
518 deliver_host_address = host->address;
519 deliver_host_port = host->port;
520 deliver_domain = addr->domain;
521 transport_name = addr->transport->name;
523 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
525 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
527 !smtp_get_port(tf->port, addr, &port, US"callout"))
528 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
531 if ( ( interface == cutthrough.interface
533 && cutthrough.interface
534 && Ustrcmp(interface, cutthrough.interface) == 0
536 && port == cutthrough.host.port
539 uschar * resp = NULL;
541 /* Match! Send the RCPT TO, append the addr, set done */
543 smtp_write_command(&ctblock, FALSE, "RCPT TO:<%.1000s>\r\n",
544 transport_rcpt_address(addr,
545 (addr->transport == NULL)? FALSE :
546 addr->transport->rcpt_include_affixes)) >= 0 &&
547 cutthrough_response('2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
549 /* This would go horribly wrong if a callout fail was ignored by ACL.
550 We punt by abandoning cutthrough on a reject, like the
555 address_item * na = store_get(sizeof(address_item));
556 *na = cutthrough.addr;
557 cutthrough.addr = *addr;
558 cutthrough.addr.host_used = &cutthrough.host;
559 cutthrough.addr.next = na;
565 cancel_cutthrough_connection("recipient rejected");
566 if (!resp || errno == ETIMEDOUT)
568 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
573 Ustrcpy(resp, US"connection dropped");
576 string_sprintf("response to \"%s\" from %s [%s] was: %s",
577 big_buffer, host->name, host->address,
578 string_printing(resp));
581 string_sprintf("Callout verification failed:\n%s", resp);
583 /* Hard rejection ends the process */
585 if (resp[0] == '5') /* Address rejected */
593 break; /* host_list */
596 cancel_cutthrough_connection("incompatible connection");
599 /* Now make connections to the hosts and do real callouts. The list of hosts
600 is passed in as an argument. */
602 for (host = host_list; host && !done; host = host->next)
606 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
608 uschar responsebuffer[4096];
610 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
611 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
613 /* Skip this host if we don't have an IP address for it. */
617 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
622 /* Check the overall callout timeout */
624 if (time(NULL) - callout_start_time >= callout_overall)
626 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
630 /* Set IPv4 or IPv6 */
632 host_af = Ustrchr(host->address, ':') == NULL ? AF_INET : AF_INET6;
634 /* Expand and interpret the interface and port strings. The latter will not
635 be used if there is a host-specific port (e.g. from a manualroute router).
636 This has to be delayed till now, because they may expand differently for
637 different hosts. If there's a failure, log it, but carry on with the
640 deliver_host = host->name;
641 deliver_host_address = host->address;
642 deliver_host_port = host->port;
643 deliver_domain = addr->domain;
644 transport_name = addr->transport->name;
646 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
648 || !smtp_get_port(tf->port, addr, &port, US"callout")
650 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
655 sx.host_af = host_af,
657 sx.interface = interface;
658 sx.helo_data = tf->helo_data;
659 sx.tblock = addr->transport;
661 tls_retry_connection:
662 /* Set the address state so that errors are recorded in it */
664 addr->transport_return = PENDING_DEFER;
665 ob->connect_timeout = callout_connect;
666 ob->command_timeout = callout;
668 /* Get the channel set up ready for a message (MAIL FROM being the next
669 SMTP command to send. If we tried TLS but it failed, try again without
672 if ( (yield = smtp_setup_conn(&sx, FALSE, TRUE)) == DEFER
673 && addr->basic_errno == ERRNO_TLSFAILURE
674 && ob->tls_tempfail_tryclear
675 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
678 log_write(0, LOG_MAIN, "TLS session failure:"
679 " callout unencrypted to %s [%s] (not in hosts_require_tls)",
680 host->name, host->address);
681 yield = smtp_setup_conn(&sx, TRUE, TRUE);
685 if (addr->message) addr->message = string_sprintf("%s [%s] %s",
686 host->name, host->address, addr->message);
687 errno = addr->basic_errno;
688 transport_name = NULL;
689 deliver_host = deliver_host_address = NULL;
690 deliver_domain = save_deliver_domain;
692 /* Failure to accept HELO is cached; this blocks the whole domain for all
693 senders. I/O errors and defer responses are not cached. */
695 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
697 setflag(addr, af_verify_nsfail);
698 new_domain_record.result = ccache_reject;
706 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
707 the AUTH info for logging */
709 addr->authenticator = client_authenticator;
710 addr->auth_id = client_authenticated_id;
712 /* Build a mail-AUTH string (re-using responsebuffer for convenience */
715 !smtp_mail_auth_str(responsebuffer, sizeof(responsebuffer), addr, ob)
717 (addr->auth_sndr = client_authenticated_sender),
719 /* Send the MAIL command */
721 (smtp_write_command(&sx.outblock, FALSE,
723 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
724 ? "MAIL FROM:<%s>%s%s SMTPUTF8\r\n"
727 "MAIL FROM:<%s>%s%s\r\n",
730 options & vopt_is_recipient && sx.peer_offered & PEER_OFFERED_SIZE
731 ? string_sprintf(" SIZE=%d", message_size + ob->size_addition)
737 && smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
740 deliver_host = deliver_host_address = NULL;
741 deliver_domain = save_deliver_domain;
743 /* If the host does not accept MAIL FROM:<>, arrange to cache this
744 information, but again, don't record anything for an I/O error or a defer. Do
745 not cache rejections of MAIL when a non-empty sender has been used, because
746 that blocks the whole domain for all senders. */
750 *failure_ptr = US"mail"; /* At or before MAIL */
751 if (errno == 0 && responsebuffer[0] == '5')
753 setflag(addr, af_verify_nsfail);
754 if (from_address[0] == 0)
755 new_domain_record.result = ccache_reject_mfnull;
759 /* Otherwise, proceed to check a "random" address (if required), then the
760 given address, and the postmaster address (if required). Between each check,
761 issue RSET, because some servers accept only one recipient after MAIL
764 Before doing this, set the result in the domain cache record to "accept",
765 unless its previous value was ccache_reject_mfnull. In that case, the domain
766 rejects MAIL FROM:<> and we want to continue to remember that. When that is
767 the case, we have got here only in the case of a recipient verification with
768 a non-null sender. */
772 const uschar * rcpt_domain = addr->domain;
775 uschar * errstr = NULL;
776 if ( testflag(addr, af_utf8_downcvt)
777 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
781 addr->message = errstr;
782 errno = ERRNO_EXPANDFAIL;
783 setflag(addr, af_verify_nsfail);
785 rcpt_domain = US""; /*XXX errorhandling! */
789 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
790 ? ccache_reject_mfnull : ccache_accept;
792 /* Do the random local part check first */
794 if (random_local_part != NULL)
796 uschar randombuffer[1024];
798 smtp_write_command(&sx.outblock, FALSE,
799 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
801 smtp_read_response(&sx.inblock, randombuffer,
802 sizeof(randombuffer), '2', callout);
804 /* Remember when we last did a random test */
806 new_domain_record.random_stamp = time(NULL);
808 /* If accepted, we aren't going to do any further tests below. */
811 new_domain_record.random_result = ccache_accept;
813 /* Otherwise, cache a real negative response, and get back to the right
814 state to send RCPT. Unless there's some problem such as a dropped
815 connection, we expect to succeed, because the commands succeeded above.
816 However, some servers drop the connection after responding to an
817 invalid recipient, so on (any) error we drop and remake the connection.
822 /* This would be ok for 1st rcpt a cutthrough, but no way to
823 handle a subsequent. So refuse to support any */
824 cancel_cutthrough_connection("random-recipient");
826 if (randombuffer[0] == '5')
827 new_domain_record.random_result = ccache_reject;
830 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
831 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
834 smtp_write_command(&sx.outblock, FALSE,
836 addr->prop.utf8_msg && !addr->prop.utf8_downcvt
837 ? "MAIL FROM:<%s> SMTPUTF8\r\n"
840 "MAIL FROM:<%s>\r\n",
841 from_address) >= 0 &&
842 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
848 debug_printf("problem after random/rset/mfrom; reopen conn\n");
849 random_local_part = NULL;
851 tls_close(FALSE, TRUE);
853 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
854 (void)close(sx.inblock.sock);
855 #ifndef DISABLE_EVENT
856 (void) event_raise(addr->transport->event_action,
857 US"tcp:close", NULL);
859 goto tls_retry_connection;
862 else done = FALSE; /* Some timeout/connection problem */
865 /* If the host is accepting all local parts, as determined by the "random"
866 check, we don't need to waste time doing any further checking. */
868 if (new_domain_record.random_result != ccache_accept && done)
870 /* Get the rcpt_include_affixes flag from the transport if there is one,
871 but assume FALSE if there is not. */
873 uschar * rcpt = transport_rcpt_address(addr,
874 addr->transport ? addr->transport->rcpt_include_affixes : FALSE);
877 /*XXX should the conversion be moved into transport_rcpt_address() ? */
878 if ( testflag(addr, af_utf8_downcvt)
879 && !(rcpt = string_address_utf8_to_alabel(rcpt, NULL))
882 errno = ERRNO_EXPANDFAIL;
883 *failure_ptr = US"recipient";
890 smtp_write_command(&sx.outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
892 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
896 new_address_record.result = ccache_accept;
897 else if (errno == 0 && responsebuffer[0] == '5')
899 *failure_ptr = US"recipient";
900 new_address_record.result = ccache_reject;
903 /* Do postmaster check if requested; if a full check is required, we
904 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
906 if (done && pm_mailfrom)
908 /* Could possibly shift before main verify, just above, and be ok
909 for cutthrough. But no way to handle a subsequent rcpt, so just
911 cancel_cutthrough_connection("postmaster verify");
912 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of postmaster verify\n");
915 smtp_write_command(&sx.outblock, FALSE, "RSET\r\n") >= 0 &&
916 smtp_read_response(&sx.inblock, responsebuffer,
917 sizeof(responsebuffer), '2', callout) &&
919 smtp_write_command(&sx.outblock, FALSE,
920 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
921 smtp_read_response(&sx.inblock, responsebuffer,
922 sizeof(responsebuffer), '2', callout) &&
924 /* First try using the current domain */
927 smtp_write_command(&sx.outblock, FALSE,
928 "RCPT TO:<postmaster@%.1000s>\r\n", rcpt_domain) >= 0 &&
929 smtp_read_response(&sx.inblock, responsebuffer,
930 sizeof(responsebuffer), '2', callout)
935 /* If that doesn't work, and a full check is requested,
936 try without the domain. */
939 (options & vopt_callout_fullpm) != 0 &&
940 smtp_write_command(&sx.outblock, FALSE,
941 "RCPT TO:<postmaster>\r\n") >= 0 &&
942 smtp_read_response(&sx.inblock, responsebuffer,
943 sizeof(responsebuffer), '2', callout)
946 /* Sort out the cache record */
948 new_domain_record.postmaster_stamp = time(NULL);
951 new_domain_record.postmaster_result = ccache_accept;
952 else if (errno == 0 && responsebuffer[0] == '5')
954 *failure_ptr = US"postmaster";
955 setflag(addr, af_verify_pmfail);
956 new_domain_record.postmaster_result = ccache_reject;
959 } /* Random not accepted */
960 } /* MAIL FROM: accepted */
962 /* For any failure of the main check, other than a negative response, we just
963 close the connection and carry on. We can identify a negative response by the
964 fact that errno is zero. For I/O errors it will be non-zero
966 Set up different error texts for logging and for sending back to the caller
967 as an SMTP response. Log in all cases, using a one-line format. For sender
968 callouts, give a full response to the caller, but for recipient callouts,
969 don't give the IP address because this may be an internal host whose identity
970 is not to be widely broadcast. */
973 if (!done) switch(errno)
976 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
977 sx.send_quit = FALSE;
983 extern int acl_where; /* src/acl.c */
985 addr->message = string_sprintf(
986 "response to \"EHLO\" from %s [%s] did not include SMTPUTF8",
987 host->name, host->address);
988 addr->user_message = acl_where == ACL_WHERE_RCPT
989 ? US"533 no support for internationalised mailbox name"
990 : US"550 mailbox unavailable";
997 sx.send_quit = FALSE;
1001 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
1004 string_sprintf("response to \"%s\" from %s [%s] was: %s",
1005 big_buffer, host->name, host->address,
1006 string_printing(responsebuffer));
1008 addr->user_message = options & vopt_is_recipient
1009 ? string_sprintf("Callout verification failed:\n%s", responsebuffer)
1010 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1011 host->address, big_buffer, responsebuffer);
1013 /* Hard rejection ends the process */
1015 if (responsebuffer[0] == '5') /* Address rejected */
1023 /* End the SMTP conversation and close the connection. */
1025 /* Cutthrough - on a successful connect and recipient-verify with
1026 use-sender and we are 1st rcpt and have no cutthrough conn so far
1027 here is where we want to leave the conn open */
1028 if ( cutthrough.delivery
1032 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1033 == vopt_callout_recipsender
1034 && !random_local_part
1036 && cutthrough.fd < 0
1040 HDEBUG(D_acl|D_v) debug_printf("holding verify callout open for cutthrough delivery\n");
1042 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1043 cutthrough.nrcpt = 1;
1044 cutthrough.interface = interface;
1045 cutthrough.host = *host;
1046 cutthrough.addr = *addr; /* Save the address_item for later logging */
1047 cutthrough.addr.next = NULL;
1048 cutthrough.addr.host_used = &cutthrough.host;
1050 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1052 ctblock.buffer = ctbuffer;
1053 ctblock.buffersize = sizeof(ctbuffer);
1054 ctblock.ptr = ctbuffer;
1055 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1056 ctblock.sock = cutthrough.fd;
1060 /* Ensure no cutthrough on multiple address verifies */
1061 if (options & vopt_callout_recipsender)
1062 cancel_cutthrough_connection("not usable for cutthrough");
1065 (void) smtp_write_command(&sx.outblock, FALSE, "QUIT\r\n");
1067 /* Wait a short time for response, and discard it */
1068 smtp_read_response(&sx.inblock, responsebuffer, sizeof(responsebuffer),
1072 if (sx.inblock.sock >= 0)
1075 tls_close(FALSE, TRUE);
1077 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1078 (void)close(sx.inblock.sock);
1079 sx.inblock.sock = sx.outblock.sock = -1;
1080 #ifndef DISABLE_EVENT
1081 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1086 } /* Loop through all hosts, while !done */
1089 /* If we get here with done == TRUE, a successful callout happened, and yield
1090 will be set OK or FAIL according to the response to the RCPT command.
1091 Otherwise, we looped through the hosts but couldn't complete the business.
1092 However, there may be domain-specific information to cache in both cases. */
1094 if (!(options & vopt_callout_no_cache))
1095 cache_callout_write(&new_domain_record, addr->domain,
1096 done, &new_address_record, address_key);
1098 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1099 temporary error. If there was only one host, and a response was received, leave
1100 it alone if supplying details. Otherwise, give a generic response. */
1104 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1105 options & vopt_is_recipient ? "recipient" : "sender");
1108 addr->message = host_list->next || !addr->message
1109 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1111 addr->user_message = smtp_return_error_details
1112 ? string_sprintf("%s for <%s>.\n"
1113 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1114 "they may be permanently unreachable from this server. In the latter case,\n%s",
1115 dullmsg, addr->address,
1116 options & vopt_is_recipient
1117 ? "the address will never be accepted."
1118 : "you need to change the address or create an MX record for its domain\n"
1119 "if it is supposed to be generally accessible from the Internet.\n"
1120 "Talk to your mail administrator for details.")
1123 /* Force a specific error code */
1125 addr->basic_errno = ERRNO_CALLOUTDEFER;
1128 /* Come here from within the cache-reading code on fast-track exit. */
1131 tls_modify_variables(&tls_in);
1137 /* Called after recipient-acl to get a cutthrough connection open when
1138 one was requested and a recipient-verify wasn't subsequently done.
1141 open_cutthrough_connection( address_item * addr )
1146 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1147 /* We must use a copy of the address for verification, because it might
1151 HDEBUG(D_acl) debug_printf("----------- %s cutthrough setup ------------\n",
1152 rcpt_count > 1 ? "more" : "start");
1153 rc = verify_address(&addr2, NULL,
1154 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1155 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1157 addr->message = addr2.message;
1158 addr->user_message = addr2.user_message;
1159 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
1165 /* Send given number of bytes from the buffer */
1167 cutthrough_send(int n)
1169 if(cutthrough.fd < 0)
1174 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1176 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1179 transport_count += n;
1180 ctblock.ptr= ctblock.buffer;
1184 HDEBUG(D_transport|D_acl) debug_printf("cutthrough_send failed: %s\n", strerror(errno));
1191 _cutthrough_puts(uschar * cp, int n)
1195 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1196 if(!cutthrough_send(ctblock.buffersize))
1199 *ctblock.ptr++ = *cp++;
1204 /* Buffered output of counted data block. Return boolean success */
1206 cutthrough_puts(uschar * cp, int n)
1208 if (cutthrough.fd < 0) return TRUE;
1209 if (_cutthrough_puts(cp, n)) return TRUE;
1210 cancel_cutthrough_connection("transmit failed");
1216 _cutthrough_flush_send(void)
1218 int n= ctblock.ptr-ctblock.buffer;
1221 if(!cutthrough_send(n))
1227 /* Send out any bufferred output. Return boolean success. */
1229 cutthrough_flush_send(void)
1231 if (_cutthrough_flush_send()) return TRUE;
1232 cancel_cutthrough_connection("transmit failed");
1238 cutthrough_put_nl(void)
1240 return cutthrough_puts(US"\r\n", 2);
1244 /* Get and check response from cutthrough target */
1246 cutthrough_response(char expect, uschar ** copy, int timeout)
1248 smtp_inblock inblock;
1249 uschar inbuffer[4096];
1250 uschar responsebuffer[4096];
1252 inblock.buffer = inbuffer;
1253 inblock.buffersize = sizeof(inbuffer);
1254 inblock.ptr = inbuffer;
1255 inblock.ptrend = inbuffer;
1256 inblock.sock = cutthrough.fd;
1257 /* this relies on (inblock.sock == tls_out.active) */
1258 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1259 cancel_cutthrough_connection("target timeout on read");
1264 *copy = cp = string_copy(responsebuffer);
1265 /* Trim the trailing end of line */
1266 cp += Ustrlen(responsebuffer);
1267 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1268 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1271 return responsebuffer[0];
1275 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1277 cutthrough_predata(void)
1279 if(cutthrough.fd < 0)
1282 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1283 cutthrough_puts(US"DATA\r\n", 6);
1284 cutthrough_flush_send();
1286 /* Assume nothing buffered. If it was it gets ignored. */
1287 return cutthrough_response('3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1291 /* fd and tctx args only to match write_chunk() */
1293 cutthrough_write_chunk(int fd, transport_ctx * tctx, uschar * s, int len)
1296 while(s && (s2 = Ustrchr(s, '\n')))
1298 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1306 /* Buffered send of headers. Return success boolean. */
1307 /* Expands newlines to wire format (CR,NL). */
1308 /* Also sends header-terminating blank line. */
1310 cutthrough_headers_send(void)
1314 if(cutthrough.fd < 0)
1317 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1318 but having a separate buffered-output function (for now)
1320 HDEBUG(D_acl) debug_printf("----------- start cutthrough headers send -----------\n");
1322 tctx.tblock = cutthrough.addr.transport;
1323 tctx.addr = &cutthrough.addr;
1324 tctx.check_string = US".";
1325 tctx.escape_string = US"..";
1326 tctx.options = topt_use_crlf;
1328 if (!transport_headers_send(cutthrough.fd, &tctx, &cutthrough_write_chunk))
1331 HDEBUG(D_acl) debug_printf("----------- done cutthrough headers send ------------\n");
1337 close_cutthrough_connection(const char * why)
1339 if(cutthrough.fd >= 0)
1341 /* We could be sending this after a bunch of data, but that is ok as
1342 the only way to cancel the transfer in dataphase is to drop the tcp
1343 conn before the final dot.
1345 ctblock.ptr = ctbuffer;
1346 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
1347 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1348 _cutthrough_flush_send();
1350 /* Wait a short time for response, and discard it */
1351 cutthrough_response('2', NULL, 1);
1354 tls_close(FALSE, TRUE);
1356 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
1357 (void)close(cutthrough.fd);
1359 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown (%s) ------------\n", why);
1361 ctblock.ptr = ctbuffer;
1365 cancel_cutthrough_connection(const char * why)
1367 close_cutthrough_connection(why);
1368 cutthrough.delivery = FALSE;
1374 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1375 Log an OK response as a transmission.
1376 Close the connection.
1377 Return smtp response-class digit.
1380 cutthrough_finaldot(void)
1383 address_item * addr;
1384 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1386 /* Assume data finshed with new-line */
1387 if( !cutthrough_puts(US".", 1)
1388 || !cutthrough_put_nl()
1389 || !cutthrough_flush_send()
1391 return cutthrough.addr.message;
1393 res = cutthrough_response('2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1394 for (addr = &cutthrough.addr; addr; addr = addr->next)
1396 addr->message = cutthrough.addr.message;
1400 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1401 close_cutthrough_connection("delivered");
1405 delivery_log(LOG_MAIN, addr, 0,
1406 US"tmp-reject from cutthrough after DATA:");
1410 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1411 US"rejected after DATA:");
1418 return cutthrough.addr.message;
1423 /*************************************************
1424 * Copy error to toplevel address *
1425 *************************************************/
1427 /* This function is used when a verify fails or defers, to ensure that the
1428 failure or defer information is in the original toplevel address. This applies
1429 when an address is redirected to a single new address, and the failure or
1430 deferral happens to the child address.
1433 vaddr the verify address item
1434 addr the final address item
1437 Returns: the value of YIELD
1441 copy_error(address_item *vaddr, address_item *addr, int yield)
1445 vaddr->message = addr->message;
1446 vaddr->user_message = addr->user_message;
1447 vaddr->basic_errno = addr->basic_errno;
1448 vaddr->more_errno = addr->more_errno;
1449 vaddr->prop.address_data = addr->prop.address_data;
1450 copyflag(vaddr, addr, af_pass_message);
1458 /**************************************************
1459 * printf that automatically handles TLS if needed *
1460 ***************************************************/
1462 /* This function is used by verify_address() as a substitute for all fprintf()
1463 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1464 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1465 that assumes that we always use the smtp_out FILE* when not using TLS or the
1466 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1467 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1471 f the candidate FILE* to write to
1472 format format string
1473 ... optional arguments
1479 static void PRINTF_FUNCTION(2,3)
1480 respond_printf(FILE *f, const char *format, ...)
1484 va_start(ap, format);
1485 if (smtp_out && (f == smtp_out))
1486 smtp_vprintf(format, ap);
1488 vfprintf(f, format, ap);
1494 /*************************************************
1495 * Verify an email address *
1496 *************************************************/
1498 /* This function is used both for verification (-bv and at other times) and
1499 address testing (-bt), which is indicated by address_test_mode being set.
1502 vaddr contains the address to verify; the next field in this block
1504 f if not NULL, write the result to this file
1505 options various option bits:
1506 vopt_fake_sender => this sender verify is not for the real
1507 sender (it was verify=sender=xxxx or an address from a
1508 header line) - rewriting must not change sender_address
1509 vopt_is_recipient => this is a recipient address, otherwise
1510 it's a sender address - this affects qualification and
1511 rewriting and messages from callouts
1512 vopt_qualify => qualify an unqualified address; else error
1513 vopt_expn => called from SMTP EXPN command
1514 vopt_success_on_redirect => when a new address is generated
1515 the verification instantly succeeds
1517 These ones are used by do_callout() -- the options variable
1520 vopt_callout_fullpm => if postmaster check, do full one
1521 vopt_callout_no_cache => don't use callout cache
1522 vopt_callout_random => do the "random" thing
1523 vopt_callout_recipsender => use real sender for recipient
1524 vopt_callout_recippmaster => use postmaster for recipient
1526 callout if > 0, specifies that callout is required, and gives timeout
1527 for individual commands
1528 callout_overall if > 0, gives overall timeout for the callout function;
1529 if < 0, a default is used (see do_callout())
1530 callout_connect the connection timeout for callouts
1531 se_mailfrom when callout is requested to verify a sender, use this
1532 in MAIL FROM; NULL => ""
1533 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1534 thing and use this as the sender address (may be "")
1536 routed if not NULL, set TRUE if routing succeeded, so we can
1537 distinguish between routing failed and callout failed
1539 Returns: OK address verified
1540 FAIL address failed to verify
1541 DEFER can't tell at present
1545 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1546 int callout_overall, int callout_connect, uschar *se_mailfrom,
1547 uschar *pm_mailfrom, BOOL *routed)
1550 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1551 BOOL expn = (options & vopt_expn) != 0;
1552 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1555 int verify_type = expn? v_expn :
1556 address_test_mode? v_none :
1557 options & vopt_is_recipient? v_recipient : v_sender;
1558 address_item *addr_list;
1559 address_item *addr_new = NULL;
1560 address_item *addr_remote = NULL;
1561 address_item *addr_local = NULL;
1562 address_item *addr_succeed = NULL;
1563 uschar **failure_ptr = options & vopt_is_recipient
1564 ? &recipient_verify_failure : &sender_verify_failure;
1565 uschar *ko_prefix, *cr;
1566 uschar *address = vaddr->address;
1567 uschar *save_sender;
1568 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1570 /* Clear, just in case */
1572 *failure_ptr = NULL;
1574 /* Set up a prefix and suffix for error message which allow us to use the same
1575 output statements both in EXPN mode (where an SMTP response is needed) and when
1576 debugging with an output file. */
1580 ko_prefix = US"553 ";
1583 else ko_prefix = cr = US"";
1585 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1587 if (parse_find_at(address) == NULL)
1589 if ((options & vopt_qualify) == 0)
1592 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1593 ko_prefix, address, cr);
1594 *failure_ptr = US"qualify";
1597 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1602 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1603 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1606 /* Rewrite and report on it. Clear the domain and local part caches - these
1607 may have been set by domains and local part tests during an ACL. */
1609 if (global_rewrite_rules != NULL)
1611 uschar *old = address;
1612 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1613 global_rewrite_rules, rewrite_existflags);
1616 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1617 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1618 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1622 /* If this is the real sender address, we must update sender_address at
1623 this point, because it may be referred to in the routers. */
1625 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1626 sender_address = address;
1628 /* If the address was rewritten to <> no verification can be done, and we have
1629 to return OK. This rewriting is permitted only for sender addresses; for other
1630 addresses, such rewriting fails. */
1632 if (address[0] == 0) return OK;
1634 /* Flip the legacy TLS-related variables over to the outbound set in case
1635 they're used in the context of a transport used by verification. Reset them
1636 at exit from this routine (so no returns allowed from here on). */
1638 tls_modify_variables(&tls_out);
1640 /* Save a copy of the sender address for re-instating if we change it to <>
1641 while verifying a sender address (a nice bit of self-reference there). */
1643 save_sender = sender_address;
1645 /* Observability variable for router/transport use */
1647 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1649 /* Update the address structure with the possibly qualified and rewritten
1650 address. Set it up as the starting address on the chain of new addresses. */
1652 vaddr->address = address;
1655 /* We need a loop, because an address can generate new addresses. We must also
1656 cope with generated pipes and files at the top level. (See also the code and
1657 comment in deliver.c.) However, it is usually the case that the router for
1658 user's .forward files has its verify flag turned off.
1660 If an address generates more than one child, the loop is used only when
1661 full_info is set, and this can only be set locally. Remote enquiries just get
1662 information about the top level address, not anything that it generated. */
1667 address_item *addr = addr_new;
1669 addr_new = addr->next;
1674 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1675 debug_printf("Considering %s\n", addr->address);
1678 /* Handle generated pipe, file or reply addresses. We don't get these
1679 when handling EXPN, as it does only one level of expansion. */
1681 if (testflag(addr, af_pfr))
1688 if (addr->address[0] == '>')
1690 allow = testflag(addr, af_allow_reply);
1691 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1695 allow = (addr->address[0] == '|')?
1696 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1697 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1700 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1701 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1702 "%s\n", addr->message);
1704 fprintf(f, "\n transport = %s\n", addr->transport->name);
1706 fprintf(f, " *** forbidden ***\n");
1711 /* Just in case some router parameter refers to it. */
1713 return_path = addr->prop.errors_address
1714 ? addr->prop.errors_address : sender_address;
1716 /* Split the address into domain and local part, handling the %-hack if
1717 necessary, and then route it. While routing a sender address, set
1718 $sender_address to <> because that is what it will be if we were trying to
1719 send a bounce to the sender. */
1721 if (routed) *routed = FALSE;
1722 if ((rc = deliver_split_address(addr)) == OK)
1724 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1725 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1726 &addr_succeed, verify_type);
1727 sender_address = save_sender; /* Put back the real sender */
1730 /* If routing an address succeeded, set the flag that remembers, for use when
1731 an ACL cached a sender verify (in case a callout fails). Then if routing set
1732 up a list of hosts or the transport has a host list, and the callout option
1733 is set, and we aren't in a host checking run, do the callout verification,
1734 and set another flag that notes that a callout happened. */
1738 if (routed) *routed = TRUE;
1741 transport_instance * tp;
1742 host_item * host_list = addr->host_list;
1744 /* Make up some data for use in the case where there is no remote
1747 transport_feedback tf = {
1748 NULL, /* interface (=> any) */
1749 US"smtp", /* port */
1750 US"smtp", /* protocol */
1752 US"$smtp_active_hostname", /* helo_data */
1753 FALSE, /* hosts_override */
1754 FALSE, /* hosts_randomize */
1755 FALSE, /* gethostbyname */
1756 TRUE, /* qualify_single */
1757 FALSE /* search_parents */
1760 /* If verification yielded a remote transport, we want to use that
1761 transport's options, so as to mimic what would happen if we were really
1762 sending a message to this address. */
1764 if ((tp = addr->transport) && !tp->info->local)
1766 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1768 /* If the transport has hosts and the router does not, or if the
1769 transport is configured to override the router's hosts, we must build a
1770 host list of the transport's hosts, and find the IP addresses */
1772 if (tf.hosts && (!host_list || tf.hosts_override))
1775 const uschar *save_deliver_domain = deliver_domain;
1776 uschar *save_deliver_localpart = deliver_localpart;
1778 host_list = NULL; /* Ignore the router's hosts */
1780 deliver_domain = addr->domain;
1781 deliver_localpart = addr->local_part;
1782 s = expand_string(tf.hosts);
1783 deliver_domain = save_deliver_domain;
1784 deliver_localpart = save_deliver_localpart;
1788 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1789 "\"%s\" in %s transport for callout: %s", tf.hosts,
1790 tp->name, expand_string_message);
1795 host_item *host, *nexthost;
1796 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1798 /* Just ignore failures to find a host address. If we don't manage
1799 to find any addresses, the callout will defer. Note that more than
1800 one address may be found for a single host, which will result in
1801 additional host items being inserted into the chain. Hence we must
1802 save the next host first. */
1804 flags = HOST_FIND_BY_A;
1805 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1806 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1808 for (host = host_list; host; host = nexthost)
1810 nexthost = host->next;
1811 if (tf.gethostbyname ||
1812 string_is_ip_address(host->name, NULL) != 0)
1813 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1816 dnssec_domains * dnssec_domains = NULL;
1817 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1819 smtp_transport_options_block * ob =
1820 (smtp_transport_options_block *) tp->options_block;
1821 dnssec_domains = &ob->dnssec;
1824 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1825 dnssec_domains, NULL, NULL);
1832 /* Can only do a callout if we have at least one host! If the callout
1833 fails, it will have set ${sender,recipient}_verify_failure. */
1837 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1838 if (host_checking && !host_checking_callout)
1841 debug_printf("... callout omitted by default when host testing\n"
1842 "(Use -bhc if you want the callouts to happen.)\n");
1847 deliver_set_expansions(addr);
1849 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1850 callout_connect, options, se_mailfrom, pm_mailfrom);
1855 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1856 "transport provided a host list\n");
1861 /* Otherwise, any failure is a routing failure */
1863 else *failure_ptr = US"route";
1865 /* A router may return REROUTED if it has set up a child address as a result
1866 of a change of domain name (typically from widening). In this case we always
1867 want to continue to verify the new child. */
1869 if (rc == REROUTED) continue;
1871 /* Handle hard failures */
1878 address_item *p = addr->parent;
1880 respond_printf(f, "%s%s %s", ko_prefix,
1881 full_info ? addr->address : address,
1882 address_test_mode ? "is undeliverable" : "failed to verify");
1883 if (!expn && admin_user)
1885 if (addr->basic_errno > 0)
1886 respond_printf(f, ": %s", strerror(addr->basic_errno));
1888 respond_printf(f, ": %s", addr->message);
1891 /* Show parents iff doing full info */
1893 if (full_info) while (p)
1895 respond_printf(f, "%s\n <-- %s", cr, p->address);
1898 respond_printf(f, "%s\n", cr);
1900 cancel_cutthrough_connection("routing hard fail");
1904 yield = copy_error(vaddr, addr, FAIL);
1912 else if (rc == DEFER)
1917 address_item *p = addr->parent;
1918 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1919 full_info? addr->address : address);
1920 if (!expn && admin_user)
1922 if (addr->basic_errno > 0)
1923 respond_printf(f, ": %s", strerror(addr->basic_errno));
1925 respond_printf(f, ": %s", addr->message);
1926 else if (addr->basic_errno <= 0)
1927 respond_printf(f, ": unknown error");
1930 /* Show parents iff doing full info */
1932 if (full_info) while (p)
1934 respond_printf(f, "%s\n <-- %s", cr, p->address);
1937 respond_printf(f, "%s\n", cr);
1939 cancel_cutthrough_connection("routing soft fail");
1943 yield = copy_error(vaddr, addr, DEFER);
1946 if (yield == OK) yield = DEFER;
1949 /* If we are handling EXPN, we do not want to continue to route beyond
1950 the top level (whose address is in "address"). */
1954 uschar *ok_prefix = US"250-";
1957 if (!addr_local && !addr_remote)
1958 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1960 respond_printf(f, "250 <%s>\r\n", address);
1964 address_item *addr2 = addr_new;
1965 addr_new = addr2->next;
1966 if (!addr_new) ok_prefix = US"250 ";
1967 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1973 /* Successful routing other than EXPN. */
1977 /* Handle successful routing when short info wanted. Otherwise continue for
1978 other (generated) addresses. Short info is the operational case. Full info
1979 can be requested only when debug_selector != 0 and a file is supplied.
1981 There is a conflict between the use of aliasing as an alternate email
1982 address, and as a sort of mailing list. If an alias turns the incoming
1983 address into just one address (e.g. J.Caesar->jc44) you may well want to
1984 carry on verifying the generated address to ensure it is valid when
1985 checking incoming mail. If aliasing generates multiple addresses, you
1986 probably don't want to do this. Exim therefore treats the generation of
1987 just a single new address as a special case, and continues on to verify the
1988 generated address. */
1990 if ( !full_info /* Stop if short info wanted AND */
1991 && ( ( !addr_new /* No new address OR */
1992 || addr_new->next /* More than one new address OR */
1993 || testflag(addr_new, af_pfr) /* New address is pfr */
1996 ( addr_new /* At least one new address AND */
1997 && success_on_redirect /* success_on_redirect is set */
2001 if (f) fprintf(f, "%s %s\n",
2002 address, address_test_mode ? "is deliverable" : "verified");
2004 /* If we have carried on to verify a child address, we want the value
2005 of $address_data to be that of the child */
2007 vaddr->prop.address_data = addr->prop.address_data;
2009 /* If stopped because more than one new address, cannot cutthrough */
2011 if (addr_new && addr_new->next)
2012 cancel_cutthrough_connection("multiple addresses from routing");
2018 } /* Loop for generated addresses */
2020 /* Display the full results of the successful routing, including any generated
2021 addresses. Control gets here only when full_info is set, which requires f not
2022 to be NULL, and this occurs only when a top-level verify is called with the
2023 debugging switch on.
2025 If there are no local and no remote addresses, and there were no pipes, files,
2026 or autoreplies, and there were no errors or deferments, the message is to be
2027 discarded, usually because of the use of :blackhole: in an alias file. */
2029 if (allok && !addr_local && !addr_remote)
2031 fprintf(f, "mail to %s is discarded\n", address);
2035 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2038 address_item *addr = addr_list;
2039 address_item *p = addr->parent;
2040 transport_instance * tp = addr->transport;
2042 addr_list = addr->next;
2044 fprintf(f, "%s", CS addr->address);
2045 #ifdef EXPERIMENTAL_SRS
2046 if(addr->prop.srs_sender)
2047 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2050 /* If the address is a duplicate, show something about it. */
2052 if (!testflag(addr, af_pfr))
2055 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2056 fprintf(f, " [duplicate, would not be delivered]");
2057 else tree_add_duplicate(addr->unique, addr);
2060 /* Now show its parents */
2062 for (p = addr->parent; p; p = p->parent)
2063 fprintf(f, "\n <-- %s", p->address);
2066 /* Show router, and transport */
2068 fprintf(f, "router = %s, transport = %s\n",
2069 addr->router->name, tp ? tp->name : US"unset");
2071 /* Show any hosts that are set up by a router unless the transport
2072 is going to override them; fiddle a bit to get a nice format. */
2074 if (addr->host_list && tp && !tp->overrides_hosts)
2079 for (h = addr->host_list; h; h = h->next)
2080 { /* get max lengths of host names, addrs */
2081 int len = Ustrlen(h->name);
2082 if (len > maxlen) maxlen = len;
2083 len = h->address ? Ustrlen(h->address) : 7;
2084 if (len > maxaddlen) maxaddlen = len;
2086 for (h = addr->host_list; h; h = h->next)
2088 fprintf(f, " host %-*s ", maxlen, h->name);
2091 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2092 else if (tp->info->local)
2093 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2095 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2097 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2098 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2099 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2100 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2106 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2107 the -bv or -bt case). */
2111 tls_modify_variables(&tls_in);
2119 /*************************************************
2120 * Check headers for syntax errors *
2121 *************************************************/
2123 /* This function checks those header lines that contain addresses, and verifies
2124 that all the addresses therein are syntactially correct.
2127 msgptr where to put an error message
2134 verify_check_headers(uschar **msgptr)
2140 for (h = header_list; h != NULL && yield == OK; h = h->next)
2142 if (h->type != htype_from &&
2143 h->type != htype_reply_to &&
2144 h->type != htype_sender &&
2145 h->type != htype_to &&
2146 h->type != htype_cc &&
2147 h->type != htype_bcc)
2150 colon = Ustrchr(h->text, ':');
2152 while (isspace(*s)) s++;
2154 /* Loop for multiple addresses in the header, enabling group syntax. Note
2155 that we have to reset this after the header has been scanned. */
2157 parse_allow_group = TRUE;
2161 uschar *ss = parse_find_address_end(s, FALSE);
2162 uschar *recipient, *errmess;
2163 int terminator = *ss;
2164 int start, end, domain;
2166 /* Temporarily terminate the string at this point, and extract the
2167 operative address within, allowing group syntax. */
2170 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2173 /* Permit an unqualified address only if the message is local, or if the
2174 sending host is configured to be permitted to send them. */
2176 if (recipient != NULL && domain == 0)
2178 if (h->type == htype_from || h->type == htype_sender)
2180 if (!allow_unqualified_sender) recipient = NULL;
2184 if (!allow_unqualified_recipient) recipient = NULL;
2186 if (recipient == NULL) errmess = US"unqualified address not permitted";
2189 /* It's an error if no address could be extracted, except for the special
2190 case of an empty address. */
2192 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2194 uschar *verb = US"is";
2199 /* Arrange not to include any white space at the end in the
2200 error message or the header name. */
2202 while (t > s && isspace(t[-1])) t--;
2203 while (tt > h->text && isspace(tt[-1])) tt--;
2205 /* Add the address that failed to the error message, since in a
2206 header with very many addresses it is sometimes hard to spot
2207 which one is at fault. However, limit the amount of address to
2208 quote - cases have been seen where, for example, a missing double
2209 quote in a humungous To: header creates an "address" that is longer
2210 than string_sprintf can handle. */
2219 /* deconst cast ok as we're passing a non-const to string_printing() */
2220 *msgptr = US string_printing(
2221 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2222 errmess, tt - h->text, h->text, verb, len, s));
2225 break; /* Out of address loop */
2228 /* Advance to the next address */
2230 s = ss + (terminator? 1:0);
2231 while (isspace(*s)) s++;
2232 } /* Next address */
2234 parse_allow_group = FALSE;
2235 parse_found_group = FALSE;
2236 } /* Next header unless yield has been set FALSE */
2242 /*************************************************
2243 * Check header names for 8-bit characters *
2244 *************************************************/
2246 /* This function checks for invalid characters in header names. See
2247 RFC 5322, 2.2. and RFC 6532, 3.
2250 msgptr where to put an error message
2257 verify_check_header_names_ascii(uschar **msgptr)
2262 for (h = header_list; h != NULL; h = h->next)
2264 colon = Ustrchr(h->text, ':');
2265 for(s = h->text; s < colon; s++)
2267 if ((*s < 33) || (*s > 126))
2269 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2270 colon - h->text, h->text);
2278 /*************************************************
2279 * Check for blind recipients *
2280 *************************************************/
2282 /* This function checks that every (envelope) recipient is mentioned in either
2283 the To: or Cc: header lines, thus detecting blind carbon copies.
2285 There are two ways of scanning that could be used: either scan the header lines
2286 and tick off the recipients, or scan the recipients and check the header lines.
2287 The original proposed patch did the former, but I have chosen to do the latter,
2288 because (a) it requires no memory and (b) will use fewer resources when there
2289 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2292 Returns: OK if there are no blind recipients
2293 FAIL if there is at least one blind recipient
2297 verify_check_notblind(void)
2300 for (i = 0; i < recipients_count; i++)
2304 uschar *address = recipients_list[i].address;
2306 for (h = header_list; !found && h != NULL; h = h->next)
2310 if (h->type != htype_to && h->type != htype_cc) continue;
2312 colon = Ustrchr(h->text, ':');
2314 while (isspace(*s)) s++;
2316 /* Loop for multiple addresses in the header, enabling group syntax. Note
2317 that we have to reset this after the header has been scanned. */
2319 parse_allow_group = TRUE;
2323 uschar *ss = parse_find_address_end(s, FALSE);
2324 uschar *recipient,*errmess;
2325 int terminator = *ss;
2326 int start, end, domain;
2328 /* Temporarily terminate the string at this point, and extract the
2329 operative address within, allowing group syntax. */
2332 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2335 /* If we found a valid recipient that has a domain, compare it with the
2336 envelope recipient. Local parts are compared case-sensitively, domains
2337 case-insensitively. By comparing from the start with length "domain", we
2338 include the "@" at the end, which ensures that we are comparing the whole
2339 local part of each address. */
2341 if (recipient != NULL && domain != 0)
2343 found = Ustrncmp(recipient, address, domain) == 0 &&
2344 strcmpic(recipient + domain, address + domain) == 0;
2348 /* Advance to the next address */
2350 s = ss + (terminator? 1:0);
2351 while (isspace(*s)) s++;
2352 } /* Next address */
2354 parse_allow_group = FALSE;
2355 parse_found_group = FALSE;
2356 } /* Next header (if found is false) */
2358 if (!found) return FAIL;
2359 } /* Next recipient */
2366 /*************************************************
2367 * Find if verified sender *
2368 *************************************************/
2370 /* Usually, just a single address is verified as the sender of the message.
2371 However, Exim can be made to verify other addresses as well (often related in
2372 some way), and this is useful in some environments. There may therefore be a
2373 chain of such addresses that have previously been tested. This function finds
2374 whether a given address is on the chain.
2376 Arguments: the address to be verified
2377 Returns: pointer to an address item, or NULL
2381 verify_checked_sender(uschar *sender)
2384 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2385 if (Ustrcmp(sender, addr->address) == 0) break;
2393 /*************************************************
2394 * Get valid header address *
2395 *************************************************/
2397 /* Scan the originator headers of the message, looking for an address that
2398 verifies successfully. RFC 822 says:
2400 o The "Sender" field mailbox should be sent notices of
2401 any problems in transport or delivery of the original
2402 messages. If there is no "Sender" field, then the
2403 "From" field mailbox should be used.
2405 o If the "Reply-To" field exists, then the reply should
2406 go to the addresses indicated in that field and not to
2407 the address(es) indicated in the "From" field.
2409 So we check a Sender field if there is one, else a Reply_to field, else a From
2410 field. As some strange messages may have more than one of these fields,
2411 especially if they are resent- fields, check all of them if there is more than
2415 user_msgptr points to where to put a user error message
2416 log_msgptr points to where to put a log error message
2417 callout timeout for callout check (passed to verify_address())
2418 callout_overall overall callout timeout (ditto)
2419 callout_connect connect callout timeout (ditto)
2420 se_mailfrom mailfrom for verify; NULL => ""
2421 pm_mailfrom sender for pm callout check (passed to verify_address())
2422 options callout options (passed to verify_address())
2423 verrno where to put the address basic_errno
2425 If log_msgptr is set to something without setting user_msgptr, the caller
2426 normally uses log_msgptr for both things.
2428 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2429 FAIL is given if no appropriate headers are found
2433 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2434 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2435 uschar *pm_mailfrom, int options, int *verrno)
2437 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2442 for (i = 0; i < 3 && !done; i++)
2445 for (h = header_list; h != NULL && !done; h = h->next)
2447 int terminator, new_ok;
2448 uschar *s, *ss, *endname;
2450 if (h->type != header_types[i]) continue;
2451 s = endname = Ustrchr(h->text, ':') + 1;
2453 /* Scan the addresses in the header, enabling group syntax. Note that we
2454 have to reset this after the header has been scanned. */
2456 parse_allow_group = TRUE;
2460 address_item *vaddr;
2462 while (isspace(*s) || *s == ',') s++;
2463 if (*s == 0) break; /* End of header */
2465 ss = parse_find_address_end(s, FALSE);
2467 /* The terminator is a comma or end of header, but there may be white
2468 space preceding it (including newline for the last address). Move back
2469 past any white space so we can check against any cached envelope sender
2470 address verifications. */
2472 while (isspace(ss[-1])) ss--;
2476 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2477 (int)(endname - h->text), h->text, s);
2479 /* See if we have already verified this address as an envelope sender,
2480 and if so, use the previous answer. */
2482 vaddr = verify_checked_sender(s);
2484 if (vaddr != NULL && /* Previously checked */
2485 (callout <= 0 || /* No callout needed; OR */
2486 vaddr->special_action > 256)) /* Callout was done */
2488 new_ok = vaddr->special_action & 255;
2489 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2490 *ss = terminator; /* Restore shortened string */
2493 /* Otherwise we run the verification now. We must restore the shortened
2494 string before running the verification, so the headers are correct, in
2495 case there is any rewriting. */
2499 int start, end, domain;
2500 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2505 /* If we found an empty address, just carry on with the next one, but
2506 kill the message. */
2508 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2515 /* If verification failed because of a syntax error, fail this
2516 function, and ensure that the failing address gets added to the error
2519 if (address == NULL)
2522 while (ss > s && isspace(ss[-1])) ss--;
2523 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2524 "scanning for sender: %s in \"%.*s\"",
2525 endname - h->text, h->text, *log_msgptr, ss - s, s);
2531 /* Else go ahead with the sender verification. But it isn't *the*
2532 sender of the message, so set vopt_fake_sender to stop sender_address
2533 being replaced after rewriting or qualification. */
2537 vaddr = deliver_make_addr(address, FALSE);
2538 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2539 callout, callout_overall, callout_connect, se_mailfrom,
2544 /* We now have the result, either newly found, or cached. If we are
2545 giving out error details, set a specific user error. This means that the
2546 last of these will be returned to the user if all three fail. We do not
2547 set a log message - the generic one below will be used. */
2551 *verrno = vaddr->basic_errno;
2552 if (smtp_return_error_details)
2554 *user_msgptr = string_sprintf("Rejected after DATA: "
2555 "could not verify \"%.*s\" header address\n%s: %s",
2556 endname - h->text, h->text, vaddr->address, vaddr->message);
2560 /* Success or defer */
2569 if (new_ok == DEFER) yield = DEFER;
2571 /* Move on to any more addresses in the header */
2574 } /* Next address */
2576 parse_allow_group = FALSE;
2577 parse_found_group = FALSE;
2578 } /* Next header, unless done */
2579 } /* Next header type unless done */
2581 if (yield == FAIL && *log_msgptr == NULL)
2582 *log_msgptr = US"there is no valid sender in any header line";
2584 if (yield == DEFER && *log_msgptr == NULL)
2585 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2593 /*************************************************
2594 * Get RFC 1413 identification *
2595 *************************************************/
2597 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2598 the timeout is set to zero, then the query is not done. There may also be lists
2599 of hosts and nets which are exempt. To guard against malefactors sending
2600 non-printing characters which could, for example, disrupt a message's headers,
2601 make sure the string consists of printing characters only.
2604 port the port to connect to; usually this is IDENT_PORT (113), but when
2605 running in the test harness with -bh a different value is used.
2609 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2613 verify_get_ident(int port)
2615 int sock, host_af, qlen;
2616 int received_sender_port, received_interface_port, n;
2618 uschar buffer[2048];
2620 /* Default is no ident. Check whether we want to do an ident check for this
2623 sender_ident = NULL;
2624 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2627 DEBUG(D_ident) debug_printf("doing ident callback\n");
2629 /* Set up a connection to the ident port of the remote host. Bind the local end
2630 to the incoming interface address. If the sender host address is an IPv6
2631 address, the incoming interface address will also be IPv6. */
2633 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2634 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2636 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2638 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2643 if (ip_connect(sock, host_af, sender_host_address, port,
2644 rfc1413_query_timeout, TRUE) < 0)
2646 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2647 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2648 sender_host_address);
2650 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2651 sender_host_address, strerror(errno));
2655 /* Construct and send the query. */
2657 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2658 qlen = Ustrlen(buffer);
2659 if (send(sock, buffer, qlen, 0) < 0)
2661 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2665 /* Read a response line. We put it into the rest of the buffer, using several
2666 recv() calls if necessary. */
2674 int size = sizeof(buffer) - (p - buffer);
2676 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2677 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2678 if (count <= 0) goto END_OFF; /* Read error or EOF */
2680 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2681 generous, and accept a plain \n terminator as well. The only illegal
2684 for (pp = p; pp < p + count; pp++)
2686 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2689 if (pp[-1] == '\r') pp--;
2691 goto GOT_DATA; /* Break out of both loops */
2695 /* Reached the end of the data without finding \n. Let the loop continue to
2696 read some more, if there is room. */
2703 /* We have received a line of data. Check it carefully. It must start with the
2704 same two port numbers that we sent, followed by data as defined by the RFC. For
2707 12345 , 25 : USERID : UNIX :root
2709 However, the amount of white space may be different to what we sent. In the
2710 "osname" field there may be several sub-fields, comma separated. The data we
2711 actually want to save follows the third colon. Some systems put leading spaces
2712 in it - we discard those. */
2714 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2715 &received_interface_port, &n) != 2 ||
2716 received_sender_port != sender_host_port ||
2717 received_interface_port != interface_port)
2720 p = buffer + qlen + n;
2721 while(isspace(*p)) p++;
2722 if (*p++ != ':') goto END_OFF;
2723 while(isspace(*p)) p++;
2724 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2726 while(isspace(*p)) p++;
2727 if (*p++ != ':') goto END_OFF;
2728 while (*p != 0 && *p != ':') p++;
2729 if (*p++ == 0) goto END_OFF;
2730 while(isspace(*p)) p++;
2731 if (*p == 0) goto END_OFF;
2733 /* The rest of the line is the data we want. We turn it into printing
2734 characters when we save it, so that it cannot mess up the format of any logging
2735 or Received: lines into which it gets inserted. We keep a maximum of 127
2736 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2738 sender_ident = US string_printing(string_copyn(p, 127));
2739 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2749 /*************************************************
2750 * Match host to a single host-list item *
2751 *************************************************/
2753 /* This function compares a host (name or address) against a single item
2754 from a host list. The host name gets looked up if it is needed and is not
2755 already known. The function is called from verify_check_this_host() via
2756 match_check_list(), which is why most of its arguments are in a single block.
2759 arg the argument block (see below)
2760 ss the host-list item
2761 valueptr where to pass back looked up data, or NULL
2762 error for error message when returning ERROR
2765 host_name (a) the host name, or
2766 (b) NULL, implying use sender_host_name and
2767 sender_host_aliases, looking them up if required, or
2768 (c) the empty string, meaning that only IP address matches
2770 host_address the host address
2771 host_ipv4 the IPv4 address taken from an IPv6 one
2775 DEFER lookup deferred
2776 ERROR (a) failed to find the host name or IP address, or
2777 (b) unknown lookup type specified, or
2778 (c) host name encountered when only IP addresses are
2783 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2785 check_host_block *cb = (check_host_block *)arg;
2788 BOOL iplookup = FALSE;
2789 BOOL isquery = FALSE;
2790 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2795 /* Optimize for the special case when the pattern is "*". */
2797 if (*ss == '*' && ss[1] == 0) return OK;
2799 /* If the pattern is empty, it matches only in the case when there is no host -
2800 this can occur in ACL checking for SMTP input using the -bs option. In this
2801 situation, the host address is the empty string. */
2803 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2804 if (*ss == 0) return FAIL;
2806 /* If the pattern is precisely "@" then match against the primary host name,
2807 provided that host name matching is permitted; if it's "@[]" match against the
2808 local host's IP addresses. */
2814 if (isiponly) return ERROR;
2815 ss = primary_hostname;
2817 else if (Ustrcmp(ss, "@[]") == 0)
2819 ip_address_item *ip;
2820 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2821 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2826 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2827 a (possibly masked) comparison with the current IP address. */
2829 if (string_is_ip_address(ss, &maskoffset) != 0)
2830 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2832 /* The pattern is not an IP address. A common error that people make is to omit
2833 one component of an IPv4 address, either by accident, or believing that, for
2834 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,
2835 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2836 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2837 ancient specification.) To aid in debugging these cases, we give a specific
2838 error if the pattern contains only digits and dots or contains a slash preceded
2839 only by digits and dots (a slash at the start indicates a file name and of
2840 course slashes may be present in lookups, but not preceded only by digits and
2843 for (t = ss; isdigit(*t) || *t == '.'; t++);
2844 if (*t == 0 || (*t == '/' && t != ss))
2846 *error = US"malformed IPv4 address or address mask";
2850 /* See if there is a semicolon in the pattern */
2852 semicolon = Ustrchr(ss, ';');
2854 /* If we are doing an IP address only match, then all lookups must be IP
2855 address lookups, even if there is no "net-". */
2859 iplookup = semicolon != NULL;
2862 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2863 a lookup on a masked IP network, in textual form. We obey this code even if we
2864 have already set iplookup, so as to skip over the "net-" prefix and to set the
2865 mask length. The net- stuff really only applies to single-key lookups where the
2866 key is implicit. For query-style lookups the key is specified in the query.
2867 From release 4.30, the use of net- for query style is no longer needed, but we
2868 retain it for backward compatibility. */
2870 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2873 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2874 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2875 iplookup = (*t++ == '-');
2879 /* Do the IP address lookup if that is indeed what we have */
2887 uschar *filename, *key, *result;
2890 /* Find the search type */
2892 search_type = search_findtype(t, semicolon - t);
2894 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2895 search_error_message);
2897 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2898 is no file name, and the "key" is just the query. For query-style with a file
2899 name, we have to fish the file off the start of the query. For a single-key
2900 lookup, the key is the current IP address, masked appropriately, and
2901 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2902 dot separators instead of colons, except when the lookup type is "iplsearch".
2905 if (mac_islookup(search_type, lookup_absfilequery))
2907 filename = semicolon + 1;
2909 while (*key != 0 && !isspace(*key)) key++;
2910 filename = string_copyn(filename, key - filename);
2911 while (isspace(*key)) key++;
2913 else if (mac_islookup(search_type, lookup_querystyle))
2916 key = semicolon + 1;
2918 else /* Single-key style */
2920 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2922 insize = host_aton(cb->host_address, incoming);
2923 host_mask(insize, incoming, mlen);
2924 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2926 filename = semicolon + 1;
2929 /* Now do the actual lookup; note that there is no search_close() because
2930 of the caching arrangements. */
2932 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2933 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2935 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2936 if (valueptr != NULL) *valueptr = result;
2937 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2940 /* The pattern is not an IP address or network reference of any kind. That is,
2941 it is a host name pattern. If this is an IP only match, there's an error in the
2946 *error = US"cannot match host name in match_ip list";
2950 /* Check the characters of the pattern to see if they comprise only letters,
2951 digits, full stops, and hyphens (the constituents of domain names). Allow
2952 underscores, as they are all too commonly found. Sigh. Also, if
2953 allow_utf8_domains is set, allow top-bit characters. */
2955 for (t = ss; *t != 0; t++)
2956 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2957 (!allow_utf8_domains || *t < 128)) break;
2959 /* If the pattern is a complete domain name, with no fancy characters, look up
2960 its IP address and match against that. Note that a multi-homed host will add
2961 items to the chain. */
2972 /* Using byname rather than bydns here means we cannot determine dnssec
2973 status. On the other hand it is unclear how that could be either
2974 propagated up or enforced. */
2976 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2977 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2980 for (hh = &h; hh != NULL; hh = hh->next)
2982 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2986 if (rc == HOST_FIND_AGAIN) return DEFER;
2987 *error = string_sprintf("failed to find IP address for %s", ss);
2991 /* Almost all subsequent comparisons require the host name, and can be done
2992 using the general string matching function. When this function is called for
2993 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2994 must use sender_host_name and its aliases, looking them up if necessary. */
2996 if (cb->host_name != NULL) /* Explicit host name given */
2997 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3000 /* Host name not given; in principle we need the sender host name and its
3001 aliases. However, for query-style lookups, we do not need the name if the
3002 query does not contain $sender_host_name. From release 4.23, a reference to
3003 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3006 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3008 const uschar *affix;
3009 int partial, affixlen, starflags, id;
3012 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3015 if (id < 0) /* Unknown lookup type */
3017 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3018 search_error_message, ss);
3021 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3026 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3029 case DEFER: return DEFER;
3030 default: return FAIL;
3034 /* Not a query-style lookup; must ensure the host name is present, and then we
3035 do a check on the name and all its aliases. */
3037 if (sender_host_name == NULL)
3039 HDEBUG(D_host_lookup)
3040 debug_printf("sender host name required, to match against %s\n", ss);
3041 if (host_lookup_failed || host_name_lookup() != OK)
3043 *error = string_sprintf("failed to find host name for %s",
3044 sender_host_address);;
3047 host_build_sender_fullhost();
3050 /* Match on the sender host name, using the general matching function */
3052 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3056 case DEFER: return DEFER;
3059 /* If there are aliases, try matching on them. */
3061 aliases = sender_host_aliases;
3062 while (*aliases != NULL)
3064 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3067 case DEFER: return DEFER;
3076 /*************************************************
3077 * Check a specific host matches a host list *
3078 *************************************************/
3080 /* This function is passed a host list containing items in a number of
3081 different formats and the identity of a host. Its job is to determine whether
3082 the given host is in the set of hosts defined by the list. The host name is
3083 passed as a pointer so that it can be looked up if needed and not already
3084 known. This is commonly the case when called from verify_check_host() to check
3085 an incoming connection. When called from elsewhere the host name should usually
3088 This function is now just a front end to match_check_list(), which runs common
3089 code for scanning a list. We pass it the check_host() function to perform a
3093 listptr pointer to the host list
3094 cache_bits pointer to cache for named lists, or NULL
3095 host_name the host name or NULL, implying use sender_host_name and
3096 sender_host_aliases, looking them up if required
3097 host_address the IP address
3098 valueptr if not NULL, data from a lookup is passed back here
3100 Returns: OK if the host is in the defined set
3101 FAIL if the host is not in the defined set,
3102 DEFER if a data lookup deferred (not a host lookup)
3104 If the host name was needed in order to make a comparison, and could not be
3105 determined from the IP address, the result is FAIL unless the item
3106 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3109 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3110 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3113 unsigned int *local_cache_bits = cache_bits;
3114 const uschar *save_host_address = deliver_host_address;
3115 check_host_block cb;
3116 cb.host_name = host_name;
3117 cb.host_address = host_address;
3119 if (valueptr != NULL) *valueptr = NULL;
3121 /* If the host address starts off ::ffff: it is an IPv6 address in
3122 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3125 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3126 host_address + 7 : host_address;
3128 /* During the running of the check, put the IP address into $host_address. In
3129 the case of calls from the smtp transport, it will already be there. However,
3130 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3131 the safe side, any existing setting is preserved, though as I write this
3132 (November 2004) I can't see any cases where it is actually needed. */
3134 deliver_host_address = host_address;
3135 rc = match_check_list(
3136 listptr, /* the list */
3137 0, /* separator character */
3138 &hostlist_anchor, /* anchor pointer */
3139 &local_cache_bits, /* cache pointer */
3140 check_host, /* function for testing */
3141 &cb, /* argument for function */
3142 MCL_HOST, /* type of check */
3143 (host_address == sender_host_address)?
3144 US"host" : host_address, /* text for debugging */
3145 valueptr); /* where to pass back data */
3146 deliver_host_address = save_host_address;
3153 /*************************************************
3154 * Check the given host item matches a list *
3155 *************************************************/
3157 verify_check_given_host(uschar **listptr, host_item *host)
3159 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3162 /*************************************************
3163 * Check the remote host matches a list *
3164 *************************************************/
3166 /* This is a front end to verify_check_this_host(), created because checking
3167 the remote host is a common occurrence. With luck, a good compiler will spot
3168 the tail recursion and optimize it. If there's no host address, this is
3169 command-line SMTP input - check against an empty string for the address.
3172 listptr pointer to the host list
3174 Returns: the yield of verify_check_this_host(),
3175 i.e. OK, FAIL, or DEFER
3179 verify_check_host(uschar **listptr)
3181 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3182 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3189 /*************************************************
3190 * Invert an IP address *
3191 *************************************************/
3193 /* Originally just used for DNS xBL lists, now also used for the
3194 reverse_ip expansion operator.
3197 buffer where to put the answer
3198 address the address to invert
3202 invert_address(uschar *buffer, uschar *address)
3205 uschar *bptr = buffer;
3207 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3208 to the IPv4 part only. */
3210 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3212 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3215 if (host_aton(address, bin) == 1)
3219 for (i = 0; i < 4; i++)
3221 sprintf(CS bptr, "%d.", x & 255);
3222 while (*bptr) bptr++;
3227 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3228 in any DNS black lists, and the format in which they will be looked up is
3229 unknown. This is just a guess. */
3235 for (j = 3; j >= 0; j--)
3238 for (i = 0; i < 8; i++)
3240 sprintf(CS bptr, "%x.", x & 15);
3241 while (*bptr) bptr++;
3248 /* Remove trailing period -- this is needed so that both arbitrary
3249 dnsbl keydomains and inverted addresses may be combined with the
3250 same format string, "%s.%s" */
3257 /*************************************************
3258 * Perform a single dnsbl lookup *
3259 *************************************************/
3261 /* This function is called from verify_check_dnsbl() below. It is also called
3262 recursively from within itself when domain and domain_txt are different
3263 pointers, in order to get the TXT record from the alternate domain.
3266 domain the outer dnsbl domain
3267 domain_txt alternate domain to lookup TXT record on success; when the
3268 same domain is to be used, domain_txt == domain (that is,
3269 the pointers must be identical, not just the text)
3270 keydomain the current keydomain (for debug message)
3271 prepend subdomain to lookup (like keydomain, but
3272 reversed if IP address)
3273 iplist the list of matching IP addresses, or NULL for "any"
3274 bitmask true if bitmask matching is wanted
3275 match_type condition for 'succeed' result
3276 0 => Any RR in iplist (=)
3277 1 => No RR in iplist (!=)
3278 2 => All RRs in iplist (==)
3279 3 => Some RRs not in iplist (!==)
3280 the two bits are defined as MT_NOT and MT_ALL
3281 defer_return what to return for a defer
3283 Returns: OK if lookup succeeded
3288 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3289 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3295 dnsbl_cache_block *cb;
3296 int old_pool = store_pool;
3297 uschar query[256]; /* DNS domain max length */
3299 /* Construct the specific query domainname */
3301 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3303 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3304 "(ignored): %s...", query);
3308 /* Look for this query in the cache. */
3310 if ( (t = tree_search(dnsbl_cache, query))
3311 && (cb = t->data.ptr)->expiry > time(NULL)
3314 /* Previous lookup was cached */
3317 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3320 /* If not cached from a previous lookup, we must do a DNS lookup, and
3321 cache the result in permanent memory. */
3327 store_pool = POOL_PERM;
3331 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3335 { /* Set up a tree entry to cache the lookup */
3336 t = store_get(sizeof(tree_node) + Ustrlen(query));
3337 Ustrcpy(t->name, query);
3338 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3339 (void)tree_insertnode(&dnsbl_cache, t);
3342 /* Do the DNS lookup . */
3344 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3345 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3346 cb->text_set = FALSE;
3350 /* If the lookup succeeded, cache the RHS address. The code allows for
3351 more than one address - this was for complete generality and the possible
3352 use of A6 records. However, A6 records have been reduced to experimental
3353 status (August 2001) and may die out. So they may never get used at all,
3354 let alone in dnsbl records. However, leave the code here, just in case.
3356 Quite apart from one A6 RR generating multiple addresses, there are DNS
3357 lists that return more than one A record, so we must handle multiple
3358 addresses generated in that way as well.
3360 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3361 or some suitably far-future time if none were found. */
3363 if (cb->rc == DNS_SUCCEED)
3366 dns_address **addrp = &(cb->rhs);
3367 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3369 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3371 if (rr->type == T_A)
3373 dns_address *da = dns_address_from_rr(&dnsa, rr);
3377 while (da->next != NULL) da = da->next;
3378 addrp = &(da->next);
3379 if (ttl > rr->ttl) ttl = rr->ttl;
3384 /* If we didn't find any A records, change the return code. This can
3385 happen when there is a CNAME record but there are no A records for what
3388 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3391 cb->expiry = time(NULL)+ttl;
3392 store_pool = old_pool;
3395 /* We now have the result of the DNS lookup, either newly done, or cached
3396 from a previous call. If the lookup succeeded, check against the address
3397 list if there is one. This may be a positive equality list (introduced by
3398 "="), a negative equality list (introduced by "!="), a positive bitmask
3399 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3401 if (cb->rc == DNS_SUCCEED)
3403 dns_address *da = NULL;
3404 uschar *addlist = cb->rhs->address;
3406 /* For A and AAAA records, there may be multiple addresses from multiple
3407 records. For A6 records (currently not expected to be used) there may be
3408 multiple addresses from a single record. */
3410 for (da = cb->rhs->next; da != NULL; da = da->next)
3411 addlist = string_sprintf("%s, %s", addlist, da->address);
3413 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3416 /* Address list check; this can be either for equality, or via a bitmask.
3417 In the latter case, all the bits must match. */
3421 for (da = cb->rhs; da != NULL; da = da->next)
3425 const uschar *ptr = iplist;
3428 /* Handle exact matching */
3432 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3434 if (Ustrcmp(CS da->address, ip) == 0) break;
3438 /* Handle bitmask matching */
3445 /* At present, all known DNS blocking lists use A records, with
3446 IPv4 addresses on the RHS encoding the information they return. I
3447 wonder if this will linger on as the last vestige of IPv4 when IPv6
3448 is ubiquitous? Anyway, for now we use paranoia code to completely
3449 ignore IPv6 addresses. The default mask is 0, which always matches.
3450 We change this only for IPv4 addresses in the list. */
3452 if (host_aton(da->address, address) == 1) mask = address[0];
3454 /* Scan the returned addresses, skipping any that are IPv6 */
3456 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3458 if (host_aton(ip, address) != 1) continue;
3459 if ((address[0] & mask) == address[0]) break;
3465 (a) An IP address in an any ('=') list matched, or
3466 (b) No IP address in an all ('==') list matched
3468 then we're done searching. */
3470 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3473 /* If da == NULL, either
3475 (a) No IP address in an any ('=') list matched, or
3476 (b) An IP address in an all ('==') list didn't match
3478 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3481 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3489 res = US"was no match";
3492 res = US"was an exclude match";
3495 res = US"was an IP address that did not match";
3498 res = US"were no IP addresses that did not match";
3501 debug_printf("=> but we are not accepting this block class because\n");
3502 debug_printf("=> there %s for %s%c%s\n",
3504 ((match_type & MT_ALL) == 0)? "" : "=",
3505 bitmask? '&' : '=', iplist);
3511 /* Either there was no IP list, or the record matched, implying that the
3512 domain is on the list. We now want to find a corresponding TXT record. If an
3513 alternate domain is specified for the TXT record, call this function
3514 recursively to look that up; this has the side effect of re-checking that
3515 there is indeed an A record at the alternate domain. */
3517 if (domain_txt != domain)
3518 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3519 FALSE, match_type, defer_return);
3521 /* If there is no alternate domain, look up a TXT record in the main domain
3522 if it has not previously been cached. */
3526 cb->text_set = TRUE;
3527 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3530 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3532 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3533 if (rr->type == T_TXT) break;
3536 int len = (rr->data)[0];
3537 if (len > 511) len = 127;
3538 store_pool = POOL_PERM;
3539 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3540 store_pool = old_pool;
3545 dnslist_value = addlist;
3546 dnslist_text = cb->text;
3550 /* There was a problem with the DNS lookup */
3552 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3554 log_write(L_dnslist_defer, LOG_MAIN,
3555 "DNS list lookup defer (probably timeout) for %s: %s", query,
3556 (defer_return == OK)? US"assumed in list" :
3557 (defer_return == FAIL)? US"assumed not in list" :
3558 US"returned DEFER");
3559 return defer_return;
3562 /* No entry was found in the DNS; continue for next domain */
3566 debug_printf("DNS lookup for %s failed\n", query);
3567 debug_printf("=> that means %s is not listed at %s\n",
3577 /*************************************************
3578 * Check host against DNS black lists *
3579 *************************************************/
3581 /* This function runs checks against a list of DNS black lists, until one
3582 matches. Each item on the list can be of the form
3584 domain=ip-address/key
3586 The domain is the right-most domain that is used for the query, for example,
3587 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3588 if the DNS lookup returns a matching IP address. Several addresses may be
3589 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3591 If no key is given, what is looked up in the domain is the inverted IP address
3592 of the current client host. If a key is given, it is used to construct the
3593 domain for the lookup. For example:
3595 dsn.rfc-ignorant.org/$sender_address_domain
3597 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3598 then we check for a TXT record for an error message, and if found, save its
3599 value in $dnslist_text. We also cache everything in a tree, to optimize
3602 The TXT record is normally looked up in the same domain as the A record, but
3603 when many lists are combined in a single DNS domain, this will not be a very
3604 specific message. It is possible to specify a different domain for looking up
3605 TXT records; this is given before the main domain, comma-separated. For
3608 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3609 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3611 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3613 Note: an address for testing RBL is 192.203.178.39
3614 Note: an address for testing DUL is 192.203.178.4
3615 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3619 listptr the domain/address/data list
3620 log_msgptr log message on error
3622 Returns: OK successful lookup (i.e. the address is on the list), or
3623 lookup deferred after +include_unknown
3624 FAIL name not found, or no data found for the given type, or
3625 lookup deferred after +exclude_unknown (default)
3626 DEFER lookup failure, if +defer_unknown was set
3630 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3633 int defer_return = FAIL;
3634 const uschar *list = *listptr;
3637 uschar buffer[1024];
3638 uschar revadd[128]; /* Long enough for IPv6 address */
3640 /* Indicate that the inverted IP address is not yet set up */
3644 /* In case this is the first time the DNS resolver is being used. */
3646 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3648 /* Loop through all the domains supplied, until something matches */
3650 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3653 BOOL bitmask = FALSE;
3660 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3662 /* Deal with special values that change the behaviour on defer */
3664 if (domain[0] == '+')
3666 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3667 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3668 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3670 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3675 /* See if there's explicit data to be looked up */
3677 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3679 /* See if there's a list of addresses supplied after the domain name. This is
3680 introduced by an = or a & character; if preceded by = we require all matches
3681 and if preceded by ! we invert the result. */
3683 if (!(iplist = Ustrchr(domain, '=')))
3686 iplist = Ustrchr(domain, '&');
3689 if (iplist) /* Found either = or & */
3691 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3693 match_type |= MT_NOT;
3697 *iplist++ = 0; /* Terminate domain, move on */
3699 /* If we found = (bitmask == FALSE), check for == or =& */
3701 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3703 bitmask = *iplist++ == '&';
3704 match_type |= MT_ALL;
3709 /* If there is a comma in the domain, it indicates that a second domain for
3710 looking up TXT records is provided, before the main domain. Otherwise we must
3711 set domain_txt == domain. */
3713 domain_txt = domain;
3714 comma = Ustrchr(domain, ',');
3721 /* Check that what we have left is a sensible domain name. There is no reason
3722 why these domains should in fact use the same syntax as hosts and email
3723 domains, but in practice they seem to. However, there is little point in
3724 actually causing an error here, because that would no doubt hold up incoming
3725 mail. Instead, I'll just log it. */
3727 for (s = domain; *s != 0; s++)
3729 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3731 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3732 "strange characters - is this right?", domain);
3737 /* Check the alternate domain if present */
3739 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3741 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3743 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3744 "strange characters - is this right?", domain_txt);
3749 /* If there is no key string, construct the query by adding the domain name
3750 onto the inverted host address, and perform a single DNS lookup. */
3754 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3756 *log_msgptr = string_sprintf
3757 ("cannot test auto-keyed dnslists condition in %s ACL",
3758 acl_wherenames[where]);
3761 if (sender_host_address == NULL) return FAIL; /* can never match */
3762 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3763 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3764 iplist, bitmask, match_type, defer_return);
3767 dnslist_domain = string_copy(domain_txt);
3768 dnslist_matched = string_copy(sender_host_address);
3769 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3770 sender_host_address, dnslist_domain);
3772 if (rc != FAIL) return rc; /* OK or DEFER */
3775 /* If there is a key string, it can be a list of domains or IP addresses to
3776 be concatenated with the main domain. */
3783 uschar keybuffer[256];
3784 uschar keyrevadd[128];
3786 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3787 sizeof(keybuffer))) != NULL)
3789 uschar *prepend = keydomain;
3791 if (string_is_ip_address(keydomain, NULL) != 0)
3793 invert_address(keyrevadd, keydomain);
3794 prepend = keyrevadd;
3797 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3798 bitmask, match_type, defer_return);
3802 dnslist_domain = string_copy(domain_txt);
3803 dnslist_matched = string_copy(keydomain);
3804 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3805 keydomain, dnslist_domain);
3809 /* If the lookup deferred, remember this fact. We keep trying the rest
3810 of the list to see if we get a useful result, and if we don't, we return
3811 DEFER at the end. */
3813 if (rc == DEFER) defer = TRUE;
3814 } /* continue with next keystring domain/address */
3816 if (defer) return DEFER;
3818 } /* continue with next dnsdb outer domain */
3825 /* End of verify.c */