1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with verifying things. The original code for callout
9 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
13 #include "transports/smtp.h"
15 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
16 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
17 static smtp_outblock ctblock;
18 uschar ctbuffer[8192];
21 /* Structure for caching DNSBL lookups */
23 typedef struct dnsbl_cache_block {
32 /* Anchor for DNSBL cache */
34 static tree_node *dnsbl_cache = NULL;
37 /* Bits for match_type in one_check_dnsbl() */
42 static uschar cutthrough_response(int, char, uschar **, int);
46 /*************************************************
47 * Retrieve a callout cache record *
48 *************************************************/
50 /* If a record exists, check whether it has expired.
53 dbm_file an open hints file
55 type "address" or "domain"
56 positive_expire expire time for positive records
57 negative_expire expire time for negative records
59 Returns: the cache record if a non-expired one exists, else NULL
62 static dbdata_callout_cache *
63 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
64 int positive_expire, int negative_expire)
69 dbdata_callout_cache *cache_record;
71 cache_record = dbfn_read_with_length(dbm_file, key, &length);
73 if (cache_record == NULL)
75 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
79 /* We treat a record as "negative" if its result field is not positive, or if
80 it is a domain record and the postmaster field is negative. */
82 negative = cache_record->result != ccache_accept ||
83 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
84 expire = negative? negative_expire : positive_expire;
87 if (now - cache_record->time_stamp > expire)
89 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
93 /* If this is a non-reject domain record, check for the obsolete format version
94 that doesn't have the postmaster and random timestamps, by looking at the
95 length. If so, copy it to a new-style block, replicating the record's
96 timestamp. Then check the additional timestamps. (There's no point wasting
97 effort if connections are rejected.) */
99 if (type[0] == 'd' && cache_record->result != ccache_reject)
101 if (length == sizeof(dbdata_callout_cache_obs))
103 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
104 memcpy(new, cache_record, length);
105 new->postmaster_stamp = new->random_stamp = new->time_stamp;
109 if (now - cache_record->postmaster_stamp > expire)
110 cache_record->postmaster_result = ccache_unknown;
112 if (now - cache_record->random_stamp > expire)
113 cache_record->random_result = ccache_unknown;
116 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
122 /* Check the callout cache.
123 Options * pm_mailfrom may be modified by cache partial results.
125 Return: TRUE if result found
129 cached_callout_lookup(address_item * addr, uschar * address_key,
130 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
131 int * yield, uschar ** failure_ptr,
132 dbdata_callout_cache * new_domain_record, int * old_domain_res)
134 int options = *opt_ptr;
136 open_db *dbm_file = NULL;
138 /* Open the callout cache database, it it exists, for reading only at this
139 stage, unless caching has been disabled. */
141 if (options & vopt_callout_no_cache)
143 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
145 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)))
147 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
151 /* If a cache database is available see if we can avoid the need to do an
152 actual callout by making use of previously-obtained data. */
154 dbdata_callout_cache_address * cache_address_record;
155 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
156 addr->domain, US"domain",
157 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
159 /* If an unexpired cache record was found for this domain, see if the callout
160 process can be short-circuited. */
164 /* In most cases, if an early command (up to and including MAIL FROM:<>)
165 was rejected, there is no point carrying on. The callout fails. However, if
166 we are doing a recipient verification with use_sender or use_postmaster
167 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
168 will be using a non-empty sender. We have to remember this situation so as
169 not to disturb the cached domain value if this whole verification succeeds
170 (we don't want it turning into "accept"). */
172 *old_domain_res = cache_record->result;
174 if ( cache_record->result == ccache_reject
175 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
177 setflag(addr, af_verify_nsfail);
179 debug_printf("callout cache: domain gave initial rejection, or "
180 "does not accept HELO or MAIL FROM:<>\n");
181 setflag(addr, af_verify_nsfail);
182 addr->user_message = US"(result of an earlier callout reused).";
184 *failure_ptr = US"mail";
185 dbfn_close(dbm_file);
189 /* If a previous check on a "random" local part was accepted, we assume
190 that the server does not do any checking on local parts. There is therefore
191 no point in doing the callout, because it will always be successful. If a
192 random check previously failed, arrange not to do it again, but preserve
193 the data in the new record. If a random check is required but hasn't been
194 done, skip the remaining cache processing. */
196 if (options & vopt_callout_random) switch(cache_record->random_result)
200 debug_printf("callout cache: domain accepts random addresses\n");
201 dbfn_close(dbm_file);
202 return TRUE; /* Default yield is OK */
206 debug_printf("callout cache: domain rejects random addresses\n");
207 *opt_ptr = options & ~vopt_callout_random;
208 new_domain_record->random_result = ccache_reject;
209 new_domain_record->random_stamp = cache_record->random_stamp;
214 debug_printf("callout cache: need to check random address handling "
215 "(not cached or cache expired)\n");
216 dbfn_close(dbm_file);
220 /* If a postmaster check is requested, but there was a previous failure,
221 there is again no point in carrying on. If a postmaster check is required,
222 but has not been done before, we are going to have to do a callout, so skip
223 remaining cache processing. */
227 if (cache_record->postmaster_result == ccache_reject)
229 setflag(addr, af_verify_pmfail);
231 debug_printf("callout cache: domain does not accept "
232 "RCPT TO:<postmaster@domain>\n");
234 *failure_ptr = US"postmaster";
235 setflag(addr, af_verify_pmfail);
236 addr->user_message = US"(result of earlier verification reused).";
237 dbfn_close(dbm_file);
240 if (cache_record->postmaster_result == ccache_unknown)
243 debug_printf("callout cache: need to check RCPT "
244 "TO:<postmaster@domain> (not cached or cache expired)\n");
245 dbfn_close(dbm_file);
249 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
250 postmaster check if the address itself has to be checked. Also ensure
251 that the value in the cache record is preserved (with its old timestamp).
254 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
255 "TO:<postmaster@domain>\n");
257 new_domain_record->postmaster_result = ccache_accept;
258 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
262 /* We can't give a result based on information about the domain. See if there
263 is an unexpired cache record for this specific address (combined with the
264 sender address if we are doing a recipient callout with a non-empty sender).
267 if (!(cache_address_record = (dbdata_callout_cache_address *)
268 get_callout_cache_record(dbm_file, address_key, US"address",
269 callout_cache_positive_expire, callout_cache_negative_expire)))
271 dbfn_close(dbm_file);
275 if (cache_address_record->result == ccache_accept)
278 debug_printf("callout cache: address record is positive\n");
283 debug_printf("callout cache: address record is negative\n");
284 addr->user_message = US"Previous (cached) callout verification failure";
285 *failure_ptr = US"recipient";
289 /* Close the cache database while we actually do the callout for real. */
291 dbfn_close(dbm_file);
298 /* Write results to callout cache
301 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
302 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
305 open_db *dbm_file = NULL;
307 /* If we get here with done == TRUE, a successful callout happened, and yield
308 will be set OK or FAIL according to the response to the RCPT command.
309 Otherwise, we looped through the hosts but couldn't complete the business.
310 However, there may be domain-specific information to cache in both cases.
312 The value of the result field in the new_domain record is ccache_unknown if
313 there was an error before or with MAIL FROM:, and errno was not zero,
314 implying some kind of I/O error. We don't want to write the cache in that case.
315 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
317 if (dom_rec->result != ccache_unknown)
318 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE)))
320 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
324 (void)dbfn_write(dbm_file, domain, dom_rec,
325 (int)sizeof(dbdata_callout_cache));
326 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
327 " result=%d postmaster=%d random=%d\n",
330 dom_rec->postmaster_result,
331 dom_rec->random_result);
334 /* If a definite result was obtained for the callout, cache it unless caching
337 if (done && addr_rec->result != ccache_unknown)
340 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
343 HDEBUG(D_verify) debug_printf("no callout cache available\n");
347 (void)dbfn_write(dbm_file, address_key, addr_rec,
348 (int)sizeof(dbdata_callout_cache_address));
349 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
350 addr_rec->result == ccache_accept ? "positive" : "negative",
355 if (dbm_file) dbfn_close(dbm_file);
359 /* Cutthrough-multi. If the existing cached cutthrough connection matches
360 the one we would make for a subsequent recipient, use it. Send the RCPT TO
361 and check the result, nonpipelined as it may be wanted immediately for
362 recipient-verification.
364 It seems simpler to deal with this case separately from the main callout loop.
365 We will need to remember it has sent, or not, so that rcpt-acl tail code
366 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
368 Return: TRUE for a definitive result for the recipient
371 cutthrough_multi(address_item * addr, host_item * host_list,
372 transport_feedback * tf, int * yield)
377 if (addr->transport == cutthrough.addr.transport)
378 for (host = host_list; host; host = host->next)
379 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
382 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
385 deliver_host = host->name;
386 deliver_host_address = host->address;
387 deliver_host_port = host->port;
388 deliver_domain = addr->domain;
389 transport_name = addr->transport->name;
391 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
393 if (!smtp_get_interface(tf->interface, host_af, addr, &interface,
395 !smtp_get_port(tf->port, addr, &port, US"callout"))
396 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
399 if ( ( interface == cutthrough.interface
401 && cutthrough.interface
402 && Ustrcmp(interface, cutthrough.interface) == 0
404 && port == cutthrough.host.port
407 uschar * resp = NULL;
409 /* Match! Send the RCPT TO, set done from the response */
411 smtp_write_command(&ctblock, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
412 transport_rcpt_address(addr,
413 addr->transport->rcpt_include_affixes)) >= 0 &&
414 cutthrough_response(cutthrough.fd, '2', &resp, CUTTHROUGH_DATA_TIMEOUT) == '2';
416 /* This would go horribly wrong if a callout fail was ignored by ACL.
417 We punt by abandoning cutthrough on a reject, like the
422 address_item * na = store_get(sizeof(address_item));
423 *na = cutthrough.addr;
424 cutthrough.addr = *addr;
425 cutthrough.addr.host_used = &cutthrough.host;
426 cutthrough.addr.next = na;
432 cancel_cutthrough_connection(TRUE, US"recipient rejected");
433 if (!resp || errno == ETIMEDOUT)
435 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
440 Ustrcpy(resp, US"connection dropped");
443 string_sprintf("response to \"%s\" was: %s",
444 big_buffer, string_printing(resp));
447 string_sprintf("Callout verification failed:\n%s", resp);
449 /* Hard rejection ends the process */
451 if (resp[0] == '5') /* Address rejected */
459 break; /* host_list */
462 cancel_cutthrough_connection(TRUE, US"incompatible connection");
467 /*************************************************
468 * Do callout verification for an address *
469 *************************************************/
471 /* This function is called from verify_address() when the address has routed to
472 a host list, and a callout has been requested. Callouts are expensive; that is
473 why a cache is used to improve the efficiency.
476 addr the address that's been routed
477 host_list the list of hosts to try
478 tf the transport feedback block
480 ifstring "interface" option from transport, or NULL
481 portstring "port" option from transport, or NULL
482 protocolstring "protocol" option from transport, or NULL
483 callout the per-command callout timeout
484 callout_overall the overall callout timeout (if < 0 use 4*callout)
485 callout_connect the callout connection timeout (if < 0 use callout)
486 options the verification options - these bits are used:
487 vopt_is_recipient => this is a recipient address
488 vopt_callout_no_cache => don't use callout cache
489 vopt_callout_fullpm => if postmaster check, do full one
490 vopt_callout_random => do the "random" thing
491 vopt_callout_recipsender => use real sender for recipient
492 vopt_callout_recippmaster => use postmaster for recipient
493 vopt_callout_hold => lazy close connection
494 se_mailfrom MAIL FROM address for sender verify; NULL => ""
495 pm_mailfrom if non-NULL, do the postmaster check with this sender
497 Returns: OK/FAIL/DEFER
501 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
502 int callout, int callout_overall, int callout_connect, int options,
503 uschar *se_mailfrom, uschar *pm_mailfrom)
506 int old_domain_cache_result = ccache_accept;
509 uschar *from_address;
510 uschar *random_local_part = NULL;
511 const uschar *save_deliver_domain = deliver_domain;
512 uschar **failure_ptr = options & vopt_is_recipient
513 ? &recipient_verify_failure : &sender_verify_failure;
514 dbdata_callout_cache new_domain_record;
515 dbdata_callout_cache_address new_address_record;
516 time_t callout_start_time;
518 new_domain_record.result = ccache_unknown;
519 new_domain_record.postmaster_result = ccache_unknown;
520 new_domain_record.random_result = ccache_unknown;
522 memset(&new_address_record, 0, sizeof(new_address_record));
524 /* For a recipient callout, the key used for the address cache record must
525 include the sender address if we are using the real sender in the callout,
526 because that may influence the result of the callout. */
528 if (options & vopt_is_recipient)
529 if (options & vopt_callout_recipsender)
531 from_address = sender_address;
532 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
533 if (cutthrough.delivery) options |= vopt_callout_no_cache;
535 else if (options & vopt_callout_recippmaster)
537 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
538 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
539 qualify_domain_sender);
544 address_key = addr->address;
547 /* For a sender callout, we must adjust the key if the mailfrom address is not
552 from_address = se_mailfrom ? se_mailfrom : US"";
553 address_key = *from_address
554 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
557 if (cached_callout_lookup(addr, address_key, from_address,
558 &options, &pm_mailfrom, &yield, failure_ptr,
559 &new_domain_record, &old_domain_cache_result))
561 cancel_cutthrough_connection(TRUE, US"cache-hit");
565 if (!addr->transport)
567 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
569 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
570 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
571 addr->transport->name, addr->transport->driver_name);
574 smtp_transport_options_block *ob =
575 (smtp_transport_options_block *)addr->transport->options_block;
578 /* The information wasn't available in the cache, so we have to do a real
579 callout and save the result in the cache for next time, unless no_cache is set,
580 or unless we have a previously cached negative random result. If we are to test
581 with a random local part, ensure that such a local part is available. If not,
582 log the fact, but carry on without randomising. */
584 if (options & vopt_callout_random && callout_random_local_part)
585 if (!(random_local_part = expand_string(callout_random_local_part)))
586 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
587 "callout_random_local_part: %s", expand_string_message);
589 /* Default the connect and overall callout timeouts if not set, and record the
590 time we are starting so that we can enforce it. */
592 if (callout_overall < 0) callout_overall = 4 * callout;
593 if (callout_connect < 0) callout_connect = callout;
594 callout_start_time = time(NULL);
596 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
597 output because a callout might take some time. When PIPELINING is active and
598 there are many recipients, the total time for doing lots of callouts can add up
599 and cause the client to time out. So in this case we forgo the PIPELINING
602 if (smtp_out && !disable_callout_flush) mac_smtp_fflush();
604 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
605 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
607 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
608 and we are holding a cutthrough conn open, we can just append the rcpt to
609 that conn for verification purposes (and later delivery also). Simplest
610 coding means skipping this whole loop and doing the append separately. */
612 /* Can we re-use an open cutthrough connection? */
613 if ( cutthrough.fd >= 0
614 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
615 == vopt_callout_recipsender
616 && !random_local_part
619 done = cutthrough_multi(addr, host_list, tf, &yield);
621 /* If we did not use a cached connection, make connections to the hosts
622 and do real callouts. The list of hosts is passed in as an argument. */
624 for (host = host_list; host && !done; host = host->next)
628 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
633 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
638 /* Check the overall callout timeout */
640 if (time(NULL) - callout_start_time >= callout_overall)
642 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
646 /* Set IPv4 or IPv6 */
648 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
650 /* Expand and interpret the interface and port strings. The latter will not
651 be used if there is a host-specific port (e.g. from a manualroute router).
652 This has to be delayed till now, because they may expand differently for
653 different hosts. If there's a failure, log it, but carry on with the
656 deliver_host = host->name;
657 deliver_host_address = host->address;
658 deliver_host_port = host->port;
659 deliver_domain = addr->domain;
660 transport_name = addr->transport->name;
662 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
664 || !smtp_get_port(tf->port, addr, &port, US"callout")
666 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
671 sx.host_af = host_af,
673 sx.interface = interface;
674 sx.helo_data = tf->helo_data;
675 sx.tblock = addr->transport;
678 tls_retry_connection:
679 /* Set the address state so that errors are recorded in it */
681 addr->transport_return = PENDING_DEFER;
682 ob->connect_timeout = callout_connect;
683 ob->command_timeout = callout;
685 /* Get the channel set up ready for a message (MAIL FROM being the next
686 SMTP command to send. If we tried TLS but it failed, try again without
689 yield = smtp_setup_conn(&sx, FALSE);
692 && addr->basic_errno == ERRNO_TLSFAILURE
693 && ob->tls_tempfail_tryclear
694 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
697 log_write(0, LOG_MAIN,
698 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
699 addr->message, host->name, host->address);
700 addr->transport_return = PENDING_DEFER;
701 yield = smtp_setup_conn(&sx, TRUE);
706 errno = addr->basic_errno;
707 transport_name = NULL;
708 deliver_host = deliver_host_address = NULL;
709 deliver_domain = save_deliver_domain;
711 /* Failure to accept HELO is cached; this blocks the whole domain for all
712 senders. I/O errors and defer responses are not cached. */
714 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
716 setflag(addr, af_verify_nsfail);
717 new_domain_record.result = ccache_reject;
725 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
726 the AUTH info for logging */
728 addr->authenticator = client_authenticator;
729 addr->auth_id = client_authenticated_id;
731 sx.from_addr = from_address;
732 sx.first_addr = sx.sync_addr = addr;
733 sx.ok = FALSE; /*XXX these 3 last might not be needed for verify? */
735 sx.completed_addr = FALSE;
737 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
738 ? ccache_reject_mfnull : ccache_accept;
740 /* Do the random local part check first. Temporarily replace the recipient
741 with the "random" value */
743 if (random_local_part)
745 uschar * main_address = addr->address;
746 const uschar * rcpt_domain = addr->domain;
749 uschar * errstr = NULL;
750 if ( testflag(addr, af_utf8_downcvt)
751 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
755 addr->message = errstr;
756 errno = ERRNO_EXPANDFAIL;
757 setflag(addr, af_verify_nsfail);
759 rcpt_domain = US""; /*XXX errorhandling! */
763 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
764 subsequents are done in cutthrough_multi()), but no way to
765 handle a subsequent because of the RSET vaporising the MAIL FROM.
766 So refuse to support any. Most cutthrough use will not involve
767 random_local_part, so no loss. */
768 cancel_cutthrough_connection(TRUE, US"random-recipient");
770 addr->address = string_sprintf("%s@%.1000s",
771 random_local_part, rcpt_domain);
774 /* If accepted, we aren't going to do any further tests below.
775 Otherwise, cache a real negative response, and get back to the right
776 state to send RCPT. Unless there's some problem such as a dropped
777 connection, we expect to succeed, because the commands succeeded above.
778 However, some servers drop the connection after responding to an
779 invalid recipient, so on (any) error we drop and remake the connection.
780 XXX We don't care about that for postmaster_full. Should we?
782 XXX could we add another flag to the context, and have the common
783 code emit the RSET too? Even pipelined after the RCPT...
784 Then the main-verify call could use it if there's to be a subsequent
786 The sync_responses() would need to be taught about it and we'd
787 need another return code filtering out to here.
790 /* Remember when we last did a random test */
791 new_domain_record.random_stamp = time(NULL);
793 if (smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0)
794 switch(addr->transport_return)
797 new_domain_record.random_result = ccache_accept;
800 new_domain_record.random_result = ccache_reject;
802 /* Between each check, issue RSET, because some servers accept only
803 one recipient after MAIL FROM:<>.
804 XXX We don't care about that for postmaster_full. Should we? */
807 smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0 &&
808 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
813 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
814 random_local_part = NULL;
816 tls_close(FALSE, TRUE);
818 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
819 (void)close(sx.inblock.sock);
820 sx.inblock.sock = sx.outblock.sock = -1;
821 #ifndef DISABLE_EVENT
822 (void) event_raise(addr->transport->event_action,
823 US"tcp:close", NULL);
825 addr->address = main_address;
826 addr->transport_return = PENDING_DEFER;
827 sx.first_addr = sx.sync_addr = addr;
830 sx.completed_addr = FALSE;
831 goto tls_retry_connection;
834 /* Re-setup for main verify, or for the error message when failing */
835 addr->address = main_address;
836 addr->transport_return = PENDING_DEFER;
837 sx.first_addr = sx.sync_addr = addr;
840 sx.completed_addr = FALSE;
845 /* Main verify. If the host is accepting all local parts, as determined
846 by the "random" check, we don't need to waste time doing any further
852 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
854 case 0: switch(addr->transport_return) /* ok so far */
856 case PENDING_OK: done = TRUE;
857 new_address_record.result = ccache_accept;
859 case FAIL: done = TRUE;
861 *failure_ptr = US"recipient";
862 new_address_record.result = ccache_reject;
868 case -1: /* MAIL response error */
869 *failure_ptr = US"mail";
870 if (errno == 0 && sx.buffer[0] == '5')
872 setflag(addr, af_verify_nsfail);
873 if (from_address[0] == 0)
874 new_domain_record.result = ccache_reject_mfnull;
877 /* non-MAIL read i/o error */
878 /* non-MAIL response timeout */
879 /* internal error; channel still usable */
880 default: break; /* transmit failed */
884 addr->auth_sndr = client_authenticated_sender;
886 deliver_host = deliver_host_address = NULL;
887 deliver_domain = save_deliver_domain;
889 /* Do postmaster check if requested; if a full check is required, we
890 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
892 if (done && pm_mailfrom)
894 /* Could possibly shift before main verify, just above, and be ok
895 for cutthrough. But no way to handle a subsequent rcpt, so just
897 cancel_cutthrough_connection(TRUE, US"postmaster verify");
898 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
900 done = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0
901 && smtp_read_response(&sx.inblock, sx.buffer,
902 sizeof(sx.buffer), '2', callout);
906 uschar * main_address = addr->address;
908 /*XXX oops, affixes */
909 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
910 addr->transport_return = PENDING_DEFER;
912 sx.from_addr = pm_mailfrom;
913 sx.first_addr = sx.sync_addr = addr;
916 sx.completed_addr = FALSE;
918 if( smtp_write_mail_and_rcpt_cmds(&sx, &yield) == 0
919 && addr->transport_return == PENDING_OK
923 done = (options & vopt_callout_fullpm) != 0
924 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
925 "RCPT TO:<postmaster>\r\n") >= 0
926 && smtp_read_response(&sx.inblock, sx.buffer,
927 sizeof(sx.buffer), '2', callout);
929 /* Sort out the cache record */
931 new_domain_record.postmaster_stamp = time(NULL);
934 new_domain_record.postmaster_result = ccache_accept;
935 else if (errno == 0 && sx.buffer[0] == '5')
937 *failure_ptr = US"postmaster";
938 setflag(addr, af_verify_pmfail);
939 new_domain_record.postmaster_result = ccache_reject;
942 addr->address = main_address;
945 /* For any failure of the main check, other than a negative response, we just
946 close the connection and carry on. We can identify a negative response by the
947 fact that errno is zero. For I/O errors it will be non-zero
949 Set up different error texts for logging and for sending back to the caller
950 as an SMTP response. Log in all cases, using a one-line format. For sender
951 callouts, give a full response to the caller, but for recipient callouts,
952 don't give the IP address because this may be an internal host whose identity
953 is not to be widely broadcast. */
959 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
960 sx.send_quit = FALSE;
966 extern int acl_where; /* src/acl.c */
968 addr->message = string_sprintf(
969 "response to \"EHLO\" did not include SMTPUTF8");
970 addr->user_message = acl_where == ACL_WHERE_RCPT
971 ? US"533 no support for internationalised mailbox name"
972 : US"550 mailbox unavailable";
979 sx.send_quit = FALSE;
983 if (*sx.buffer == 0) Ustrcpy(sx.buffer, US"connection dropped");
985 /*XXX test here is ugly; seem to have a split of responsibility for
986 building this message. Need to reationalise. Where is it done
987 before here, and when not?
988 Not == 5xx resp to MAIL on main-verify
990 if (!addr->message) addr->message =
991 string_sprintf("response to \"%s\" was: %s",
992 big_buffer, string_printing(sx.buffer));
994 addr->user_message = options & vopt_is_recipient
995 ? string_sprintf("Callout verification failed:\n%s", sx.buffer)
996 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
997 host->address, big_buffer, sx.buffer);
999 /* Hard rejection ends the process */
1001 if (sx.buffer[0] == '5') /* Address rejected */
1009 /* End the SMTP conversation and close the connection. */
1011 /* Cutthrough - on a successful connect and recipient-verify with
1012 use-sender and we are 1st rcpt and have no cutthrough conn so far
1013 here is where we want to leave the conn open. Ditto for a lazy-close
1016 if ( (cutthrough.delivery || options & vopt_callout_hold)
1020 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1021 == vopt_callout_recipsender
1022 && !random_local_part
1024 && cutthrough.fd < 0
1028 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1030 ? "cutthrough delivery" : "potential further verifies and delivery");
1032 cutthrough.callout_hold_only = !cutthrough.delivery;
1033 cutthrough.is_tls = tls_out.active >= 0;
1034 cutthrough.fd = sx.outblock.sock; /* We assume no buffer in use in the outblock */
1035 cutthrough.nrcpt = 1;
1036 cutthrough.transport = addr->transport->name;
1037 cutthrough.interface = interface;
1038 cutthrough.snd_port = sending_port;
1039 cutthrough.peer_options = smtp_peer_options;
1040 cutthrough.host = *host;
1042 int oldpool = store_pool;
1043 store_pool = POOL_PERM;
1044 cutthrough.snd_ip = string_copy(sending_ip_address);
1045 cutthrough.host.name = string_copy(host->name);
1046 cutthrough.host.address = string_copy(host->address);
1047 store_pool = oldpool;
1049 cutthrough.addr = *addr; /* Save the address_item for later logging */
1050 cutthrough.addr.next = NULL;
1051 cutthrough.addr.host_used = &cutthrough.host;
1053 *(cutthrough.addr.parent = store_get(sizeof(address_item))) =
1055 ctblock.buffer = ctbuffer;
1056 ctblock.buffersize = sizeof(ctbuffer);
1057 ctblock.ptr = ctbuffer;
1058 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1059 ctblock.sock = cutthrough.fd;
1063 /* Ensure no cutthrough on multiple verifies that were incompatible */
1064 if (options & vopt_callout_recipsender)
1065 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1068 (void) smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
1070 /* Wait a short time for response, and discard it */
1071 smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
1075 if (sx.inblock.sock >= 0)
1078 tls_close(FALSE, TRUE);
1080 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1081 (void)close(sx.inblock.sock);
1082 sx.inblock.sock = sx.outblock.sock = -1;
1083 #ifndef DISABLE_EVENT
1084 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1089 if (!done || yield != OK)
1090 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1092 } /* Loop through all hosts, while !done */
1095 /* If we get here with done == TRUE, a successful callout happened, and yield
1096 will be set OK or FAIL according to the response to the RCPT command.
1097 Otherwise, we looped through the hosts but couldn't complete the business.
1098 However, there may be domain-specific information to cache in both cases. */
1100 if (!(options & vopt_callout_no_cache))
1101 cache_callout_write(&new_domain_record, addr->domain,
1102 done, &new_address_record, address_key);
1104 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1105 temporary error. If there was only one host, and a response was received, leave
1106 it alone if supplying details. Otherwise, give a generic response. */
1110 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1111 options & vopt_is_recipient ? "recipient" : "sender");
1114 addr->message = host_list->next || !addr->message
1115 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1117 addr->user_message = smtp_return_error_details
1118 ? string_sprintf("%s for <%s>.\n"
1119 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1120 "they may be permanently unreachable from this server. In the latter case,\n%s",
1121 dullmsg, addr->address,
1122 options & vopt_is_recipient
1123 ? "the address will never be accepted."
1124 : "you need to change the address or create an MX record for its domain\n"
1125 "if it is supposed to be generally accessible from the Internet.\n"
1126 "Talk to your mail administrator for details.")
1129 /* Force a specific error code */
1131 addr->basic_errno = ERRNO_CALLOUTDEFER;
1134 /* Come here from within the cache-reading code on fast-track exit. */
1137 tls_modify_variables(&tls_in);
1143 /* Called after recipient-acl to get a cutthrough connection open when
1144 one was requested and a recipient-verify wasn't subsequently done.
1147 open_cutthrough_connection( address_item * addr )
1152 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1153 /* We must use a copy of the address for verification, because it might
1157 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1158 rcpt_count > 1 ? "more" : "start");
1159 rc = verify_address(&addr2, NULL,
1160 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1161 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1163 addr->message = addr2.message;
1164 addr->user_message = addr2.user_message;
1165 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1171 /* Send given number of bytes from the buffer */
1173 cutthrough_send(int n)
1175 if(cutthrough.fd < 0)
1180 (tls_out.active == cutthrough.fd) ? tls_write(FALSE, ctblock.buffer, n) :
1182 send(cutthrough.fd, ctblock.buffer, n, 0) > 0
1185 transport_count += n;
1186 ctblock.ptr= ctblock.buffer;
1190 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1197 _cutthrough_puts(uschar * cp, int n)
1201 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
1202 if(!cutthrough_send(ctblock.buffersize))
1205 *ctblock.ptr++ = *cp++;
1210 /* Buffered output of counted data block. Return boolean success */
1212 cutthrough_puts(uschar * cp, int n)
1214 if (cutthrough.fd < 0) return TRUE;
1215 if (_cutthrough_puts(cp, n)) return TRUE;
1216 cancel_cutthrough_connection(TRUE, US"transmit failed");
1221 cutthrough_data_puts(uschar * cp, int n)
1223 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1229 _cutthrough_flush_send(void)
1231 int n = ctblock.ptr - ctblock.buffer;
1234 if(!cutthrough_send(n))
1240 /* Send out any bufferred output. Return boolean success. */
1242 cutthrough_flush_send(void)
1244 if (_cutthrough_flush_send()) return TRUE;
1245 cancel_cutthrough_connection(TRUE, US"transmit failed");
1251 cutthrough_put_nl(void)
1253 return cutthrough_puts(US"\r\n", 2);
1258 cutthrough_data_put_nl(void)
1260 cutthrough_data_puts(US"\r\n", 2);
1264 /* Get and check response from cutthrough target */
1266 cutthrough_response(int fd, char expect, uschar ** copy, int timeout)
1268 smtp_inblock inblock;
1269 uschar inbuffer[4096];
1270 uschar responsebuffer[4096];
1272 inblock.buffer = inbuffer;
1273 inblock.buffersize = sizeof(inbuffer);
1274 inblock.ptr = inbuffer;
1275 inblock.ptrend = inbuffer;
1277 /* this relies on (inblock.sock == tls_out.active) */
1278 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, timeout))
1279 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1284 *copy = cp = string_copy(responsebuffer);
1285 /* Trim the trailing end of line */
1286 cp += Ustrlen(responsebuffer);
1287 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1288 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1291 return responsebuffer[0];
1295 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1297 cutthrough_predata(void)
1299 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1302 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1303 cutthrough_puts(US"DATA\r\n", 6);
1304 cutthrough_flush_send();
1306 /* Assume nothing buffered. If it was it gets ignored. */
1307 return cutthrough_response(cutthrough.fd, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1311 /* tctx arg only to match write_chunk() */
1313 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1316 while(s && (s2 = Ustrchr(s, '\n')))
1318 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1326 /* Buffered send of headers. Return success boolean. */
1327 /* Expands newlines to wire format (CR,NL). */
1328 /* Also sends header-terminating blank line. */
1330 cutthrough_headers_send(void)
1334 if(cutthrough.fd < 0 || cutthrough.callout_hold_only)
1337 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1338 but having a separate buffered-output function (for now)
1340 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1342 tctx.u.fd = cutthrough.fd;
1343 tctx.tblock = cutthrough.addr.transport;
1344 tctx.addr = &cutthrough.addr;
1345 tctx.check_string = US".";
1346 tctx.escape_string = US"..";
1347 /*XXX check under spool_files_wireformat. Might be irrelevant */
1348 tctx.options = topt_use_crlf;
1350 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1353 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1359 close_cutthrough_connection(const uschar * why)
1361 int fd = cutthrough.fd;
1364 /* We could be sending this after a bunch of data, but that is ok as
1365 the only way to cancel the transfer in dataphase is to drop the tcp
1366 conn before the final dot.
1368 ctblock.ptr = ctbuffer;
1369 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1370 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1371 _cutthrough_flush_send();
1372 cutthrough.fd = -1; /* avoid recursion via read timeout */
1374 /* Wait a short time for response, and discard it */
1375 cutthrough_response(fd, '2', NULL, 1);
1378 tls_close(FALSE, TRUE);
1380 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1382 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1384 ctblock.ptr = ctbuffer;
1388 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1390 if (cutthrough.delivery || close_noncutthrough_verifies)
1391 close_cutthrough_connection(why);
1392 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1397 release_cutthrough_connection(const uschar * why)
1399 if (cutthrough.fd < 0) return;
1400 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1402 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1408 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1409 Log an OK response as a transmission.
1410 Close the connection.
1411 Return smtp response-class digit.
1414 cutthrough_finaldot(void)
1417 address_item * addr;
1418 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1420 /* Assume data finshed with new-line */
1421 if( !cutthrough_puts(US".", 1)
1422 || !cutthrough_put_nl()
1423 || !cutthrough_flush_send()
1425 return cutthrough.addr.message;
1427 res = cutthrough_response(cutthrough.fd, '2', &cutthrough.addr.message, CUTTHROUGH_DATA_TIMEOUT);
1428 for (addr = &cutthrough.addr; addr; addr = addr->next)
1430 addr->message = cutthrough.addr.message;
1434 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1435 close_cutthrough_connection(US"delivered");
1439 delivery_log(LOG_MAIN, addr, 0,
1440 US"tmp-reject from cutthrough after DATA:");
1444 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1445 US"rejected after DATA:");
1452 return cutthrough.addr.message;
1457 /*************************************************
1458 * Copy error to toplevel address *
1459 *************************************************/
1461 /* This function is used when a verify fails or defers, to ensure that the
1462 failure or defer information is in the original toplevel address. This applies
1463 when an address is redirected to a single new address, and the failure or
1464 deferral happens to the child address.
1467 vaddr the verify address item
1468 addr the final address item
1471 Returns: the value of YIELD
1475 copy_error(address_item *vaddr, address_item *addr, int yield)
1479 vaddr->message = addr->message;
1480 vaddr->user_message = addr->user_message;
1481 vaddr->basic_errno = addr->basic_errno;
1482 vaddr->more_errno = addr->more_errno;
1483 vaddr->prop.address_data = addr->prop.address_data;
1484 copyflag(vaddr, addr, af_pass_message);
1492 /**************************************************
1493 * printf that automatically handles TLS if needed *
1494 ***************************************************/
1496 /* This function is used by verify_address() as a substitute for all fprintf()
1497 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1498 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1499 that assumes that we always use the smtp_out FILE* when not using TLS or the
1500 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1501 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1505 f the candidate FILE* to write to
1506 format format string
1507 ... optional arguments
1513 static void PRINTF_FUNCTION(2,3)
1514 respond_printf(FILE *f, const char *format, ...)
1518 va_start(ap, format);
1519 if (smtp_out && (f == smtp_out))
1520 smtp_vprintf(format, ap);
1522 vfprintf(f, format, ap);
1528 /*************************************************
1529 * Verify an email address *
1530 *************************************************/
1532 /* This function is used both for verification (-bv and at other times) and
1533 address testing (-bt), which is indicated by address_test_mode being set.
1536 vaddr contains the address to verify; the next field in this block
1538 f if not NULL, write the result to this file
1539 options various option bits:
1540 vopt_fake_sender => this sender verify is not for the real
1541 sender (it was verify=sender=xxxx or an address from a
1542 header line) - rewriting must not change sender_address
1543 vopt_is_recipient => this is a recipient address, otherwise
1544 it's a sender address - this affects qualification and
1545 rewriting and messages from callouts
1546 vopt_qualify => qualify an unqualified address; else error
1547 vopt_expn => called from SMTP EXPN command
1548 vopt_success_on_redirect => when a new address is generated
1549 the verification instantly succeeds
1551 These ones are used by do_callout() -- the options variable
1554 vopt_callout_fullpm => if postmaster check, do full one
1555 vopt_callout_no_cache => don't use callout cache
1556 vopt_callout_random => do the "random" thing
1557 vopt_callout_recipsender => use real sender for recipient
1558 vopt_callout_recippmaster => use postmaster for recipient
1560 callout if > 0, specifies that callout is required, and gives timeout
1561 for individual commands
1562 callout_overall if > 0, gives overall timeout for the callout function;
1563 if < 0, a default is used (see do_callout())
1564 callout_connect the connection timeout for callouts
1565 se_mailfrom when callout is requested to verify a sender, use this
1566 in MAIL FROM; NULL => ""
1567 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1568 thing and use this as the sender address (may be "")
1570 routed if not NULL, set TRUE if routing succeeded, so we can
1571 distinguish between routing failed and callout failed
1573 Returns: OK address verified
1574 FAIL address failed to verify
1575 DEFER can't tell at present
1579 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1580 int callout_overall, int callout_connect, uschar *se_mailfrom,
1581 uschar *pm_mailfrom, BOOL *routed)
1584 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1585 BOOL expn = (options & vopt_expn) != 0;
1586 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1589 int verify_type = expn? v_expn :
1590 address_test_mode? v_none :
1591 options & vopt_is_recipient? v_recipient : v_sender;
1592 address_item *addr_list;
1593 address_item *addr_new = NULL;
1594 address_item *addr_remote = NULL;
1595 address_item *addr_local = NULL;
1596 address_item *addr_succeed = NULL;
1597 uschar **failure_ptr = options & vopt_is_recipient
1598 ? &recipient_verify_failure : &sender_verify_failure;
1599 uschar *ko_prefix, *cr;
1600 uschar *address = vaddr->address;
1601 uschar *save_sender;
1602 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1604 /* Clear, just in case */
1606 *failure_ptr = NULL;
1608 /* Set up a prefix and suffix for error message which allow us to use the same
1609 output statements both in EXPN mode (where an SMTP response is needed) and when
1610 debugging with an output file. */
1614 ko_prefix = US"553 ";
1617 else ko_prefix = cr = US"";
1619 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1621 if (parse_find_at(address) == NULL)
1623 if ((options & vopt_qualify) == 0)
1626 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1627 ko_prefix, address, cr);
1628 *failure_ptr = US"qualify";
1631 address = rewrite_address_qualify(address, options & vopt_is_recipient);
1636 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1637 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1640 /* Rewrite and report on it. Clear the domain and local part caches - these
1641 may have been set by domains and local part tests during an ACL. */
1643 if (global_rewrite_rules != NULL)
1645 uschar *old = address;
1646 address = rewrite_address(address, options & vopt_is_recipient, FALSE,
1647 global_rewrite_rules, rewrite_existflags);
1650 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1651 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1652 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1656 /* If this is the real sender address, we must update sender_address at
1657 this point, because it may be referred to in the routers. */
1659 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1660 sender_address = address;
1662 /* If the address was rewritten to <> no verification can be done, and we have
1663 to return OK. This rewriting is permitted only for sender addresses; for other
1664 addresses, such rewriting fails. */
1666 if (address[0] == 0) return OK;
1668 /* Flip the legacy TLS-related variables over to the outbound set in case
1669 they're used in the context of a transport used by verification. Reset them
1670 at exit from this routine (so no returns allowed from here on). */
1672 tls_modify_variables(&tls_out);
1674 /* Save a copy of the sender address for re-instating if we change it to <>
1675 while verifying a sender address (a nice bit of self-reference there). */
1677 save_sender = sender_address;
1679 /* Observability variable for router/transport use */
1681 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1683 /* Update the address structure with the possibly qualified and rewritten
1684 address. Set it up as the starting address on the chain of new addresses. */
1686 vaddr->address = address;
1689 /* We need a loop, because an address can generate new addresses. We must also
1690 cope with generated pipes and files at the top level. (See also the code and
1691 comment in deliver.c.) However, it is usually the case that the router for
1692 user's .forward files has its verify flag turned off.
1694 If an address generates more than one child, the loop is used only when
1695 full_info is set, and this can only be set locally. Remote enquiries just get
1696 information about the top level address, not anything that it generated. */
1701 address_item *addr = addr_new;
1703 addr_new = addr->next;
1708 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1709 debug_printf("Considering %s\n", addr->address);
1712 /* Handle generated pipe, file or reply addresses. We don't get these
1713 when handling EXPN, as it does only one level of expansion. */
1715 if (testflag(addr, af_pfr))
1722 if (addr->address[0] == '>')
1724 allow = testflag(addr, af_allow_reply);
1725 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1729 allow = (addr->address[0] == '|')?
1730 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1731 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1734 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1735 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1736 "%s\n", addr->message);
1738 fprintf(f, "\n transport = %s\n", addr->transport->name);
1740 fprintf(f, " *** forbidden ***\n");
1745 /* Just in case some router parameter refers to it. */
1747 return_path = addr->prop.errors_address
1748 ? addr->prop.errors_address : sender_address;
1750 /* Split the address into domain and local part, handling the %-hack if
1751 necessary, and then route it. While routing a sender address, set
1752 $sender_address to <> because that is what it will be if we were trying to
1753 send a bounce to the sender. */
1755 if (routed) *routed = FALSE;
1756 if ((rc = deliver_split_address(addr)) == OK)
1758 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1759 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1760 &addr_succeed, verify_type);
1761 sender_address = save_sender; /* Put back the real sender */
1764 /* If routing an address succeeded, set the flag that remembers, for use when
1765 an ACL cached a sender verify (in case a callout fails). Then if routing set
1766 up a list of hosts or the transport has a host list, and the callout option
1767 is set, and we aren't in a host checking run, do the callout verification,
1768 and set another flag that notes that a callout happened. */
1772 if (routed) *routed = TRUE;
1775 transport_instance * tp;
1776 host_item * host_list = addr->host_list;
1778 /* Make up some data for use in the case where there is no remote
1781 transport_feedback tf = {
1782 NULL, /* interface (=> any) */
1783 US"smtp", /* port */
1784 US"smtp", /* protocol */
1786 US"$smtp_active_hostname", /* helo_data */
1787 FALSE, /* hosts_override */
1788 FALSE, /* hosts_randomize */
1789 FALSE, /* gethostbyname */
1790 TRUE, /* qualify_single */
1791 FALSE /* search_parents */
1794 /* If verification yielded a remote transport, we want to use that
1795 transport's options, so as to mimic what would happen if we were really
1796 sending a message to this address. */
1798 if ((tp = addr->transport) && !tp->info->local)
1800 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1802 /* If the transport has hosts and the router does not, or if the
1803 transport is configured to override the router's hosts, we must build a
1804 host list of the transport's hosts, and find the IP addresses */
1806 if (tf.hosts && (!host_list || tf.hosts_override))
1809 const uschar *save_deliver_domain = deliver_domain;
1810 uschar *save_deliver_localpart = deliver_localpart;
1812 host_list = NULL; /* Ignore the router's hosts */
1814 deliver_domain = addr->domain;
1815 deliver_localpart = addr->local_part;
1816 s = expand_string(tf.hosts);
1817 deliver_domain = save_deliver_domain;
1818 deliver_localpart = save_deliver_localpart;
1822 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1823 "\"%s\" in %s transport for callout: %s", tf.hosts,
1824 tp->name, expand_string_message);
1829 host_item *host, *nexthost;
1830 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1832 /* Just ignore failures to find a host address. If we don't manage
1833 to find any addresses, the callout will defer. Note that more than
1834 one address may be found for a single host, which will result in
1835 additional host items being inserted into the chain. Hence we must
1836 save the next host first. */
1838 flags = HOST_FIND_BY_A;
1839 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1840 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1842 for (host = host_list; host; host = nexthost)
1844 nexthost = host->next;
1845 if (tf.gethostbyname ||
1846 string_is_ip_address(host->name, NULL) != 0)
1847 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1850 dnssec_domains * dnssec_domains = NULL;
1851 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1853 smtp_transport_options_block * ob =
1854 (smtp_transport_options_block *) tp->options_block;
1855 dnssec_domains = &ob->dnssec;
1858 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1859 dnssec_domains, NULL, NULL);
1866 /* Can only do a callout if we have at least one host! If the callout
1867 fails, it will have set ${sender,recipient}_verify_failure. */
1871 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1872 if (host_checking && !host_checking_callout)
1875 debug_printf("... callout omitted by default when host testing\n"
1876 "(Use -bhc if you want the callouts to happen.)\n");
1881 deliver_set_expansions(addr);
1883 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1884 callout_connect, options, se_mailfrom, pm_mailfrom);
1889 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1890 "transport provided a host list\n");
1895 /* Otherwise, any failure is a routing failure */
1897 else *failure_ptr = US"route";
1899 /* A router may return REROUTED if it has set up a child address as a result
1900 of a change of domain name (typically from widening). In this case we always
1901 want to continue to verify the new child. */
1903 if (rc == REROUTED) continue;
1905 /* Handle hard failures */
1912 address_item *p = addr->parent;
1914 respond_printf(f, "%s%s %s", ko_prefix,
1915 full_info ? addr->address : address,
1916 address_test_mode ? "is undeliverable" : "failed to verify");
1917 if (!expn && admin_user)
1919 if (addr->basic_errno > 0)
1920 respond_printf(f, ": %s", strerror(addr->basic_errno));
1922 respond_printf(f, ": %s", addr->message);
1925 /* Show parents iff doing full info */
1927 if (full_info) while (p)
1929 respond_printf(f, "%s\n <-- %s", cr, p->address);
1932 respond_printf(f, "%s\n", cr);
1934 cancel_cutthrough_connection(TRUE, US"routing hard fail");
1938 yield = copy_error(vaddr, addr, FAIL);
1946 else if (rc == DEFER)
1951 address_item *p = addr->parent;
1952 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1953 full_info? addr->address : address);
1954 if (!expn && admin_user)
1956 if (addr->basic_errno > 0)
1957 respond_printf(f, ": %s", strerror(addr->basic_errno));
1959 respond_printf(f, ": %s", addr->message);
1960 else if (addr->basic_errno <= 0)
1961 respond_printf(f, ": unknown error");
1964 /* Show parents iff doing full info */
1966 if (full_info) while (p)
1968 respond_printf(f, "%s\n <-- %s", cr, p->address);
1971 respond_printf(f, "%s\n", cr);
1973 cancel_cutthrough_connection(TRUE, US"routing soft fail");
1977 yield = copy_error(vaddr, addr, DEFER);
1980 if (yield == OK) yield = DEFER;
1983 /* If we are handling EXPN, we do not want to continue to route beyond
1984 the top level (whose address is in "address"). */
1988 uschar *ok_prefix = US"250-";
1991 if (!addr_local && !addr_remote)
1992 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1994 respond_printf(f, "250 <%s>\r\n", address);
1998 address_item *addr2 = addr_new;
1999 addr_new = addr2->next;
2000 if (!addr_new) ok_prefix = US"250 ";
2001 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
2007 /* Successful routing other than EXPN. */
2011 /* Handle successful routing when short info wanted. Otherwise continue for
2012 other (generated) addresses. Short info is the operational case. Full info
2013 can be requested only when debug_selector != 0 and a file is supplied.
2015 There is a conflict between the use of aliasing as an alternate email
2016 address, and as a sort of mailing list. If an alias turns the incoming
2017 address into just one address (e.g. J.Caesar->jc44) you may well want to
2018 carry on verifying the generated address to ensure it is valid when
2019 checking incoming mail. If aliasing generates multiple addresses, you
2020 probably don't want to do this. Exim therefore treats the generation of
2021 just a single new address as a special case, and continues on to verify the
2022 generated address. */
2024 if ( !full_info /* Stop if short info wanted AND */
2025 && ( ( !addr_new /* No new address OR */
2026 || addr_new->next /* More than one new address OR */
2027 || testflag(addr_new, af_pfr) /* New address is pfr */
2030 ( addr_new /* At least one new address AND */
2031 && success_on_redirect /* success_on_redirect is set */
2035 if (f) fprintf(f, "%s %s\n",
2036 address, address_test_mode ? "is deliverable" : "verified");
2038 /* If we have carried on to verify a child address, we want the value
2039 of $address_data to be that of the child */
2041 vaddr->prop.address_data = addr->prop.address_data;
2043 /* If stopped because more than one new address, cannot cutthrough */
2045 if (addr_new && addr_new->next)
2046 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2052 } /* Loop for generated addresses */
2054 /* Display the full results of the successful routing, including any generated
2055 addresses. Control gets here only when full_info is set, which requires f not
2056 to be NULL, and this occurs only when a top-level verify is called with the
2057 debugging switch on.
2059 If there are no local and no remote addresses, and there were no pipes, files,
2060 or autoreplies, and there were no errors or deferments, the message is to be
2061 discarded, usually because of the use of :blackhole: in an alias file. */
2063 if (allok && !addr_local && !addr_remote)
2065 fprintf(f, "mail to %s is discarded\n", address);
2069 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2072 address_item *addr = addr_list;
2073 address_item *p = addr->parent;
2074 transport_instance * tp = addr->transport;
2076 addr_list = addr->next;
2078 fprintf(f, "%s", CS addr->address);
2079 #ifdef EXPERIMENTAL_SRS
2080 if(addr->prop.srs_sender)
2081 fprintf(f, " [srs = %s]", addr->prop.srs_sender);
2084 /* If the address is a duplicate, show something about it. */
2086 if (!testflag(addr, af_pfr))
2089 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2090 fprintf(f, " [duplicate, would not be delivered]");
2091 else tree_add_duplicate(addr->unique, addr);
2094 /* Now show its parents */
2096 for (p = addr->parent; p; p = p->parent)
2097 fprintf(f, "\n <-- %s", p->address);
2100 /* Show router, and transport */
2102 fprintf(f, "router = %s, transport = %s\n",
2103 addr->router->name, tp ? tp->name : US"unset");
2105 /* Show any hosts that are set up by a router unless the transport
2106 is going to override them; fiddle a bit to get a nice format. */
2108 if (addr->host_list && tp && !tp->overrides_hosts)
2113 for (h = addr->host_list; h; h = h->next)
2114 { /* get max lengths of host names, addrs */
2115 int len = Ustrlen(h->name);
2116 if (len > maxlen) maxlen = len;
2117 len = h->address ? Ustrlen(h->address) : 7;
2118 if (len > maxaddlen) maxaddlen = len;
2120 for (h = addr->host_list; h; h = h->next)
2122 fprintf(f, " host %-*s ", maxlen, h->name);
2125 fprintf(f, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2126 else if (tp->info->local)
2127 fprintf(f, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2129 fprintf(f, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2131 if (h->mx >= 0) fprintf(f, " MX=%d", h->mx);
2132 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
2133 if (running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", f);
2134 if (h->status == hstatus_unusable) fputs(" ** unusable **", f);
2140 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2141 the -bv or -bt case). */
2145 tls_modify_variables(&tls_in);
2153 /*************************************************
2154 * Check headers for syntax errors *
2155 *************************************************/
2157 /* This function checks those header lines that contain addresses, and verifies
2158 that all the addresses therein are syntactially correct.
2161 msgptr where to put an error message
2168 verify_check_headers(uschar **msgptr)
2174 for (h = header_list; h != NULL && yield == OK; h = h->next)
2176 if (h->type != htype_from &&
2177 h->type != htype_reply_to &&
2178 h->type != htype_sender &&
2179 h->type != htype_to &&
2180 h->type != htype_cc &&
2181 h->type != htype_bcc)
2184 colon = Ustrchr(h->text, ':');
2186 while (isspace(*s)) s++;
2188 /* Loop for multiple addresses in the header, enabling group syntax. Note
2189 that we have to reset this after the header has been scanned. */
2191 parse_allow_group = TRUE;
2195 uschar *ss = parse_find_address_end(s, FALSE);
2196 uschar *recipient, *errmess;
2197 int terminator = *ss;
2198 int start, end, domain;
2200 /* Temporarily terminate the string at this point, and extract the
2201 operative address within, allowing group syntax. */
2204 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2207 /* Permit an unqualified address only if the message is local, or if the
2208 sending host is configured to be permitted to send them. */
2210 if (recipient != NULL && domain == 0)
2212 if (h->type == htype_from || h->type == htype_sender)
2214 if (!allow_unqualified_sender) recipient = NULL;
2218 if (!allow_unqualified_recipient) recipient = NULL;
2220 if (recipient == NULL) errmess = US"unqualified address not permitted";
2223 /* It's an error if no address could be extracted, except for the special
2224 case of an empty address. */
2226 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
2228 uschar *verb = US"is";
2233 /* Arrange not to include any white space at the end in the
2234 error message or the header name. */
2236 while (t > s && isspace(t[-1])) t--;
2237 while (tt > h->text && isspace(tt[-1])) tt--;
2239 /* Add the address that failed to the error message, since in a
2240 header with very many addresses it is sometimes hard to spot
2241 which one is at fault. However, limit the amount of address to
2242 quote - cases have been seen where, for example, a missing double
2243 quote in a humungous To: header creates an "address" that is longer
2244 than string_sprintf can handle. */
2253 /* deconst cast ok as we're passing a non-const to string_printing() */
2254 *msgptr = US string_printing(
2255 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2256 errmess, tt - h->text, h->text, verb, len, s));
2259 break; /* Out of address loop */
2262 /* Advance to the next address */
2264 s = ss + (terminator? 1:0);
2265 while (isspace(*s)) s++;
2266 } /* Next address */
2268 parse_allow_group = FALSE;
2269 parse_found_group = FALSE;
2270 } /* Next header unless yield has been set FALSE */
2276 /*************************************************
2277 * Check header names for 8-bit characters *
2278 *************************************************/
2280 /* This function checks for invalid characters in header names. See
2281 RFC 5322, 2.2. and RFC 6532, 3.
2284 msgptr where to put an error message
2291 verify_check_header_names_ascii(uschar **msgptr)
2296 for (h = header_list; h; h = h->next)
2298 colon = Ustrchr(h->text, ':');
2299 for(s = h->text; s < colon; s++)
2300 if ((*s < 33) || (*s > 126))
2302 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2303 colon - h->text, h->text);
2310 /*************************************************
2311 * Check for blind recipients *
2312 *************************************************/
2314 /* This function checks that every (envelope) recipient is mentioned in either
2315 the To: or Cc: header lines, thus detecting blind carbon copies.
2317 There are two ways of scanning that could be used: either scan the header lines
2318 and tick off the recipients, or scan the recipients and check the header lines.
2319 The original proposed patch did the former, but I have chosen to do the latter,
2320 because (a) it requires no memory and (b) will use fewer resources when there
2321 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2324 Returns: OK if there are no blind recipients
2325 FAIL if there is at least one blind recipient
2329 verify_check_notblind(void)
2332 for (i = 0; i < recipients_count; i++)
2336 uschar *address = recipients_list[i].address;
2338 for (h = header_list; !found && h != NULL; h = h->next)
2342 if (h->type != htype_to && h->type != htype_cc) continue;
2344 colon = Ustrchr(h->text, ':');
2346 while (isspace(*s)) s++;
2348 /* Loop for multiple addresses in the header, enabling group syntax. Note
2349 that we have to reset this after the header has been scanned. */
2351 parse_allow_group = TRUE;
2355 uschar *ss = parse_find_address_end(s, FALSE);
2356 uschar *recipient,*errmess;
2357 int terminator = *ss;
2358 int start, end, domain;
2360 /* Temporarily terminate the string at this point, and extract the
2361 operative address within, allowing group syntax. */
2364 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2367 /* If we found a valid recipient that has a domain, compare it with the
2368 envelope recipient. Local parts are compared case-sensitively, domains
2369 case-insensitively. By comparing from the start with length "domain", we
2370 include the "@" at the end, which ensures that we are comparing the whole
2371 local part of each address. */
2373 if (recipient != NULL && domain != 0)
2375 found = Ustrncmp(recipient, address, domain) == 0 &&
2376 strcmpic(recipient + domain, address + domain) == 0;
2380 /* Advance to the next address */
2382 s = ss + (terminator? 1:0);
2383 while (isspace(*s)) s++;
2384 } /* Next address */
2386 parse_allow_group = FALSE;
2387 parse_found_group = FALSE;
2388 } /* Next header (if found is false) */
2390 if (!found) return FAIL;
2391 } /* Next recipient */
2398 /*************************************************
2399 * Find if verified sender *
2400 *************************************************/
2402 /* Usually, just a single address is verified as the sender of the message.
2403 However, Exim can be made to verify other addresses as well (often related in
2404 some way), and this is useful in some environments. There may therefore be a
2405 chain of such addresses that have previously been tested. This function finds
2406 whether a given address is on the chain.
2408 Arguments: the address to be verified
2409 Returns: pointer to an address item, or NULL
2413 verify_checked_sender(uschar *sender)
2416 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
2417 if (Ustrcmp(sender, addr->address) == 0) break;
2425 /*************************************************
2426 * Get valid header address *
2427 *************************************************/
2429 /* Scan the originator headers of the message, looking for an address that
2430 verifies successfully. RFC 822 says:
2432 o The "Sender" field mailbox should be sent notices of
2433 any problems in transport or delivery of the original
2434 messages. If there is no "Sender" field, then the
2435 "From" field mailbox should be used.
2437 o If the "Reply-To" field exists, then the reply should
2438 go to the addresses indicated in that field and not to
2439 the address(es) indicated in the "From" field.
2441 So we check a Sender field if there is one, else a Reply_to field, else a From
2442 field. As some strange messages may have more than one of these fields,
2443 especially if they are resent- fields, check all of them if there is more than
2447 user_msgptr points to where to put a user error message
2448 log_msgptr points to where to put a log error message
2449 callout timeout for callout check (passed to verify_address())
2450 callout_overall overall callout timeout (ditto)
2451 callout_connect connect callout timeout (ditto)
2452 se_mailfrom mailfrom for verify; NULL => ""
2453 pm_mailfrom sender for pm callout check (passed to verify_address())
2454 options callout options (passed to verify_address())
2455 verrno where to put the address basic_errno
2457 If log_msgptr is set to something without setting user_msgptr, the caller
2458 normally uses log_msgptr for both things.
2460 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2461 FAIL is given if no appropriate headers are found
2465 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2466 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2467 uschar *pm_mailfrom, int options, int *verrno)
2469 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2474 for (i = 0; i < 3 && !done; i++)
2477 for (h = header_list; h != NULL && !done; h = h->next)
2479 int terminator, new_ok;
2480 uschar *s, *ss, *endname;
2482 if (h->type != header_types[i]) continue;
2483 s = endname = Ustrchr(h->text, ':') + 1;
2485 /* Scan the addresses in the header, enabling group syntax. Note that we
2486 have to reset this after the header has been scanned. */
2488 parse_allow_group = TRUE;
2492 address_item *vaddr;
2494 while (isspace(*s) || *s == ',') s++;
2495 if (*s == 0) break; /* End of header */
2497 ss = parse_find_address_end(s, FALSE);
2499 /* The terminator is a comma or end of header, but there may be white
2500 space preceding it (including newline for the last address). Move back
2501 past any white space so we can check against any cached envelope sender
2502 address verifications. */
2504 while (isspace(ss[-1])) ss--;
2508 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2509 (int)(endname - h->text), h->text, s);
2511 /* See if we have already verified this address as an envelope sender,
2512 and if so, use the previous answer. */
2514 vaddr = verify_checked_sender(s);
2516 if (vaddr != NULL && /* Previously checked */
2517 (callout <= 0 || /* No callout needed; OR */
2518 vaddr->special_action > 256)) /* Callout was done */
2520 new_ok = vaddr->special_action & 255;
2521 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2522 *ss = terminator; /* Restore shortened string */
2525 /* Otherwise we run the verification now. We must restore the shortened
2526 string before running the verification, so the headers are correct, in
2527 case there is any rewriting. */
2531 int start, end, domain;
2532 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2537 /* If we found an empty address, just carry on with the next one, but
2538 kill the message. */
2540 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2547 /* If verification failed because of a syntax error, fail this
2548 function, and ensure that the failing address gets added to the error
2551 if (address == NULL)
2554 while (ss > s && isspace(ss[-1])) ss--;
2555 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2556 "scanning for sender: %s in \"%.*s\"",
2557 endname - h->text, h->text, *log_msgptr, ss - s, s);
2563 /* Else go ahead with the sender verification. But it isn't *the*
2564 sender of the message, so set vopt_fake_sender to stop sender_address
2565 being replaced after rewriting or qualification. */
2569 vaddr = deliver_make_addr(address, FALSE);
2570 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2571 callout, callout_overall, callout_connect, se_mailfrom,
2576 /* We now have the result, either newly found, or cached. If we are
2577 giving out error details, set a specific user error. This means that the
2578 last of these will be returned to the user if all three fail. We do not
2579 set a log message - the generic one below will be used. */
2583 *verrno = vaddr->basic_errno;
2584 if (smtp_return_error_details)
2586 *user_msgptr = string_sprintf("Rejected after DATA: "
2587 "could not verify \"%.*s\" header address\n%s: %s",
2588 endname - h->text, h->text, vaddr->address, vaddr->message);
2592 /* Success or defer */
2601 if (new_ok == DEFER) yield = DEFER;
2603 /* Move on to any more addresses in the header */
2606 } /* Next address */
2608 parse_allow_group = FALSE;
2609 parse_found_group = FALSE;
2610 } /* Next header, unless done */
2611 } /* Next header type unless done */
2613 if (yield == FAIL && *log_msgptr == NULL)
2614 *log_msgptr = US"there is no valid sender in any header line";
2616 if (yield == DEFER && *log_msgptr == NULL)
2617 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2625 /*************************************************
2626 * Get RFC 1413 identification *
2627 *************************************************/
2629 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2630 the timeout is set to zero, then the query is not done. There may also be lists
2631 of hosts and nets which are exempt. To guard against malefactors sending
2632 non-printing characters which could, for example, disrupt a message's headers,
2633 make sure the string consists of printing characters only.
2636 port the port to connect to; usually this is IDENT_PORT (113), but when
2637 running in the test harness with -bh a different value is used.
2641 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2645 verify_get_ident(int port)
2647 int sock, host_af, qlen;
2648 int received_sender_port, received_interface_port, n;
2650 uschar buffer[2048];
2652 /* Default is no ident. Check whether we want to do an ident check for this
2655 sender_ident = NULL;
2656 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2659 DEBUG(D_ident) debug_printf("doing ident callback\n");
2661 /* Set up a connection to the ident port of the remote host. Bind the local end
2662 to the incoming interface address. If the sender host address is an IPv6
2663 address, the incoming interface address will also be IPv6. */
2665 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2666 if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2668 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2670 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2675 if (ip_connect(sock, host_af, sender_host_address, port,
2676 rfc1413_query_timeout, TRUE) < 0)
2678 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2679 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2680 sender_host_address);
2682 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2683 sender_host_address, strerror(errno));
2687 /* Construct and send the query. */
2689 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2690 qlen = Ustrlen(buffer);
2691 if (send(sock, buffer, qlen, 0) < 0)
2693 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2697 /* Read a response line. We put it into the rest of the buffer, using several
2698 recv() calls if necessary. */
2706 int size = sizeof(buffer) - (p - buffer);
2708 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2709 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2710 if (count <= 0) goto END_OFF; /* Read error or EOF */
2712 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2713 generous, and accept a plain \n terminator as well. The only illegal
2716 for (pp = p; pp < p + count; pp++)
2718 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2721 if (pp[-1] == '\r') pp--;
2723 goto GOT_DATA; /* Break out of both loops */
2727 /* Reached the end of the data without finding \n. Let the loop continue to
2728 read some more, if there is room. */
2735 /* We have received a line of data. Check it carefully. It must start with the
2736 same two port numbers that we sent, followed by data as defined by the RFC. For
2739 12345 , 25 : USERID : UNIX :root
2741 However, the amount of white space may be different to what we sent. In the
2742 "osname" field there may be several sub-fields, comma separated. The data we
2743 actually want to save follows the third colon. Some systems put leading spaces
2744 in it - we discard those. */
2746 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2747 &received_interface_port, &n) != 2 ||
2748 received_sender_port != sender_host_port ||
2749 received_interface_port != interface_port)
2752 p = buffer + qlen + n;
2753 while(isspace(*p)) p++;
2754 if (*p++ != ':') goto END_OFF;
2755 while(isspace(*p)) p++;
2756 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2758 while(isspace(*p)) p++;
2759 if (*p++ != ':') goto END_OFF;
2760 while (*p != 0 && *p != ':') p++;
2761 if (*p++ == 0) goto END_OFF;
2762 while(isspace(*p)) p++;
2763 if (*p == 0) goto END_OFF;
2765 /* The rest of the line is the data we want. We turn it into printing
2766 characters when we save it, so that it cannot mess up the format of any logging
2767 or Received: lines into which it gets inserted. We keep a maximum of 127
2768 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2770 sender_ident = US string_printing(string_copyn(p, 127));
2771 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2781 /*************************************************
2782 * Match host to a single host-list item *
2783 *************************************************/
2785 /* This function compares a host (name or address) against a single item
2786 from a host list. The host name gets looked up if it is needed and is not
2787 already known. The function is called from verify_check_this_host() via
2788 match_check_list(), which is why most of its arguments are in a single block.
2791 arg the argument block (see below)
2792 ss the host-list item
2793 valueptr where to pass back looked up data, or NULL
2794 error for error message when returning ERROR
2797 host_name (a) the host name, or
2798 (b) NULL, implying use sender_host_name and
2799 sender_host_aliases, looking them up if required, or
2800 (c) the empty string, meaning that only IP address matches
2802 host_address the host address
2803 host_ipv4 the IPv4 address taken from an IPv6 one
2807 DEFER lookup deferred
2808 ERROR (a) failed to find the host name or IP address, or
2809 (b) unknown lookup type specified, or
2810 (c) host name encountered when only IP addresses are
2815 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2817 check_host_block *cb = (check_host_block *)arg;
2820 BOOL iplookup = FALSE;
2821 BOOL isquery = FALSE;
2822 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2827 /* Optimize for the special case when the pattern is "*". */
2829 if (*ss == '*' && ss[1] == 0) return OK;
2831 /* If the pattern is empty, it matches only in the case when there is no host -
2832 this can occur in ACL checking for SMTP input using the -bs option. In this
2833 situation, the host address is the empty string. */
2835 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2836 if (*ss == 0) return FAIL;
2838 /* If the pattern is precisely "@" then match against the primary host name,
2839 provided that host name matching is permitted; if it's "@[]" match against the
2840 local host's IP addresses. */
2846 if (isiponly) return ERROR;
2847 ss = primary_hostname;
2849 else if (Ustrcmp(ss, "@[]") == 0)
2851 ip_address_item *ip;
2852 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2853 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2858 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2859 a (possibly masked) comparison with the current IP address. */
2861 if (string_is_ip_address(ss, &maskoffset) != 0)
2862 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2864 /* The pattern is not an IP address. A common error that people make is to omit
2865 one component of an IPv4 address, either by accident, or believing that, for
2866 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,
2867 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2868 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2869 ancient specification.) To aid in debugging these cases, we give a specific
2870 error if the pattern contains only digits and dots or contains a slash preceded
2871 only by digits and dots (a slash at the start indicates a file name and of
2872 course slashes may be present in lookups, but not preceded only by digits and
2875 for (t = ss; isdigit(*t) || *t == '.'; t++);
2876 if (*t == 0 || (*t == '/' && t != ss))
2878 *error = US"malformed IPv4 address or address mask";
2882 /* See if there is a semicolon in the pattern */
2884 semicolon = Ustrchr(ss, ';');
2886 /* If we are doing an IP address only match, then all lookups must be IP
2887 address lookups, even if there is no "net-". */
2891 iplookup = semicolon != NULL;
2894 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2895 a lookup on a masked IP network, in textual form. We obey this code even if we
2896 have already set iplookup, so as to skip over the "net-" prefix and to set the
2897 mask length. The net- stuff really only applies to single-key lookups where the
2898 key is implicit. For query-style lookups the key is specified in the query.
2899 From release 4.30, the use of net- for query style is no longer needed, but we
2900 retain it for backward compatibility. */
2902 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2905 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2906 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2907 iplookup = (*t++ == '-');
2911 /* Do the IP address lookup if that is indeed what we have */
2919 uschar *filename, *key, *result;
2922 /* Find the search type */
2924 search_type = search_findtype(t, semicolon - t);
2926 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2927 search_error_message);
2929 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2930 is no file name, and the "key" is just the query. For query-style with a file
2931 name, we have to fish the file off the start of the query. For a single-key
2932 lookup, the key is the current IP address, masked appropriately, and
2933 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2934 dot separators instead of colons, except when the lookup type is "iplsearch".
2937 if (mac_islookup(search_type, lookup_absfilequery))
2939 filename = semicolon + 1;
2941 while (*key != 0 && !isspace(*key)) key++;
2942 filename = string_copyn(filename, key - filename);
2943 while (isspace(*key)) key++;
2945 else if (mac_islookup(search_type, lookup_querystyle))
2948 key = semicolon + 1;
2950 else /* Single-key style */
2952 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2954 insize = host_aton(cb->host_address, incoming);
2955 host_mask(insize, incoming, mlen);
2956 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2958 filename = semicolon + 1;
2961 /* Now do the actual lookup; note that there is no search_close() because
2962 of the caching arrangements. */
2964 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
2965 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
2967 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2968 if (valueptr != NULL) *valueptr = result;
2969 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2972 /* The pattern is not an IP address or network reference of any kind. That is,
2973 it is a host name pattern. If this is an IP only match, there's an error in the
2978 *error = US"cannot match host name in match_ip list";
2982 /* Check the characters of the pattern to see if they comprise only letters,
2983 digits, full stops, and hyphens (the constituents of domain names). Allow
2984 underscores, as they are all too commonly found. Sigh. Also, if
2985 allow_utf8_domains is set, allow top-bit characters. */
2987 for (t = ss; *t != 0; t++)
2988 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2989 (!allow_utf8_domains || *t < 128)) break;
2991 /* If the pattern is a complete domain name, with no fancy characters, look up
2992 its IP address and match against that. Note that a multi-homed host will add
2993 items to the chain. */
3004 /* Using byname rather than bydns here means we cannot determine dnssec
3005 status. On the other hand it is unclear how that could be either
3006 propagated up or enforced. */
3008 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3009 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3012 for (hh = &h; hh != NULL; hh = hh->next)
3014 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3018 if (rc == HOST_FIND_AGAIN) return DEFER;
3019 *error = string_sprintf("failed to find IP address for %s", ss);
3023 /* Almost all subsequent comparisons require the host name, and can be done
3024 using the general string matching function. When this function is called for
3025 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3026 must use sender_host_name and its aliases, looking them up if necessary. */
3028 if (cb->host_name != NULL) /* Explicit host name given */
3029 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3032 /* Host name not given; in principle we need the sender host name and its
3033 aliases. However, for query-style lookups, we do not need the name if the
3034 query does not contain $sender_host_name. From release 4.23, a reference to
3035 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3038 if ((semicolon = Ustrchr(ss, ';')) != NULL)
3040 const uschar *affix;
3041 int partial, affixlen, starflags, id;
3044 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
3047 if (id < 0) /* Unknown lookup type */
3049 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3050 search_error_message, ss);
3053 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3058 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3061 case DEFER: return DEFER;
3062 default: return FAIL;
3066 /* Not a query-style lookup; must ensure the host name is present, and then we
3067 do a check on the name and all its aliases. */
3069 if (sender_host_name == NULL)
3071 HDEBUG(D_host_lookup)
3072 debug_printf("sender host name required, to match against %s\n", ss);
3073 if (host_lookup_failed || host_name_lookup() != OK)
3075 *error = string_sprintf("failed to find host name for %s",
3076 sender_host_address);;
3079 host_build_sender_fullhost();
3082 /* Match on the sender host name, using the general matching function */
3084 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
3088 case DEFER: return DEFER;
3091 /* If there are aliases, try matching on them. */
3093 aliases = sender_host_aliases;
3094 while (*aliases != NULL)
3096 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3099 case DEFER: return DEFER;
3108 /*************************************************
3109 * Check a specific host matches a host list *
3110 *************************************************/
3112 /* This function is passed a host list containing items in a number of
3113 different formats and the identity of a host. Its job is to determine whether
3114 the given host is in the set of hosts defined by the list. The host name is
3115 passed as a pointer so that it can be looked up if needed and not already
3116 known. This is commonly the case when called from verify_check_host() to check
3117 an incoming connection. When called from elsewhere the host name should usually
3120 This function is now just a front end to match_check_list(), which runs common
3121 code for scanning a list. We pass it the check_host() function to perform a
3125 listptr pointer to the host list
3126 cache_bits pointer to cache for named lists, or NULL
3127 host_name the host name or NULL, implying use sender_host_name and
3128 sender_host_aliases, looking them up if required
3129 host_address the IP address
3130 valueptr if not NULL, data from a lookup is passed back here
3132 Returns: OK if the host is in the defined set
3133 FAIL if the host is not in the defined set,
3134 DEFER if a data lookup deferred (not a host lookup)
3136 If the host name was needed in order to make a comparison, and could not be
3137 determined from the IP address, the result is FAIL unless the item
3138 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3141 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3142 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3145 unsigned int *local_cache_bits = cache_bits;
3146 const uschar *save_host_address = deliver_host_address;
3147 check_host_block cb;
3148 cb.host_name = host_name;
3149 cb.host_address = host_address;
3151 if (valueptr != NULL) *valueptr = NULL;
3153 /* If the host address starts off ::ffff: it is an IPv6 address in
3154 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3157 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
3158 host_address + 7 : host_address;
3160 /* During the running of the check, put the IP address into $host_address. In
3161 the case of calls from the smtp transport, it will already be there. However,
3162 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3163 the safe side, any existing setting is preserved, though as I write this
3164 (November 2004) I can't see any cases where it is actually needed. */
3166 deliver_host_address = host_address;
3167 rc = match_check_list(
3168 listptr, /* the list */
3169 0, /* separator character */
3170 &hostlist_anchor, /* anchor pointer */
3171 &local_cache_bits, /* cache pointer */
3172 check_host, /* function for testing */
3173 &cb, /* argument for function */
3174 MCL_HOST, /* type of check */
3175 (host_address == sender_host_address)?
3176 US"host" : host_address, /* text for debugging */
3177 valueptr); /* where to pass back data */
3178 deliver_host_address = save_host_address;
3185 /*************************************************
3186 * Check the given host item matches a list *
3187 *************************************************/
3189 verify_check_given_host(uschar **listptr, host_item *host)
3191 return verify_check_this_host(CUSS listptr, NULL, host->name, host->address, NULL);
3194 /*************************************************
3195 * Check the remote host matches a list *
3196 *************************************************/
3198 /* This is a front end to verify_check_this_host(), created because checking
3199 the remote host is a common occurrence. With luck, a good compiler will spot
3200 the tail recursion and optimize it. If there's no host address, this is
3201 command-line SMTP input - check against an empty string for the address.
3204 listptr pointer to the host list
3206 Returns: the yield of verify_check_this_host(),
3207 i.e. OK, FAIL, or DEFER
3211 verify_check_host(uschar **listptr)
3213 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3214 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
3221 /*************************************************
3222 * Invert an IP address *
3223 *************************************************/
3225 /* Originally just used for DNS xBL lists, now also used for the
3226 reverse_ip expansion operator.
3229 buffer where to put the answer
3230 address the address to invert
3234 invert_address(uschar *buffer, uschar *address)
3237 uschar *bptr = buffer;
3239 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3240 to the IPv4 part only. */
3242 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3244 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3247 if (host_aton(address, bin) == 1)
3251 for (i = 0; i < 4; i++)
3253 sprintf(CS bptr, "%d.", x & 255);
3254 while (*bptr) bptr++;
3259 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3260 in any DNS black lists, and the format in which they will be looked up is
3261 unknown. This is just a guess. */
3267 for (j = 3; j >= 0; j--)
3270 for (i = 0; i < 8; i++)
3272 sprintf(CS bptr, "%x.", x & 15);
3273 while (*bptr) bptr++;
3280 /* Remove trailing period -- this is needed so that both arbitrary
3281 dnsbl keydomains and inverted addresses may be combined with the
3282 same format string, "%s.%s" */
3289 /*************************************************
3290 * Perform a single dnsbl lookup *
3291 *************************************************/
3293 /* This function is called from verify_check_dnsbl() below. It is also called
3294 recursively from within itself when domain and domain_txt are different
3295 pointers, in order to get the TXT record from the alternate domain.
3298 domain the outer dnsbl domain
3299 domain_txt alternate domain to lookup TXT record on success; when the
3300 same domain is to be used, domain_txt == domain (that is,
3301 the pointers must be identical, not just the text)
3302 keydomain the current keydomain (for debug message)
3303 prepend subdomain to lookup (like keydomain, but
3304 reversed if IP address)
3305 iplist the list of matching IP addresses, or NULL for "any"
3306 bitmask true if bitmask matching is wanted
3307 match_type condition for 'succeed' result
3308 0 => Any RR in iplist (=)
3309 1 => No RR in iplist (!=)
3310 2 => All RRs in iplist (==)
3311 3 => Some RRs not in iplist (!==)
3312 the two bits are defined as MT_NOT and MT_ALL
3313 defer_return what to return for a defer
3315 Returns: OK if lookup succeeded
3320 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3321 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3327 dnsbl_cache_block *cb;
3328 int old_pool = store_pool;
3329 uschar query[256]; /* DNS domain max length */
3331 /* Construct the specific query domainname */
3333 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
3335 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3336 "(ignored): %s...", query);
3340 /* Look for this query in the cache. */
3342 if ( (t = tree_search(dnsbl_cache, query))
3343 && (cb = t->data.ptr)->expiry > time(NULL)
3346 /* Previous lookup was cached */
3349 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
3352 /* If not cached from a previous lookup, we must do a DNS lookup, and
3353 cache the result in permanent memory. */
3359 store_pool = POOL_PERM;
3363 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3367 { /* Set up a tree entry to cache the lookup */
3368 t = store_get(sizeof(tree_node) + Ustrlen(query));
3369 Ustrcpy(t->name, query);
3370 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
3371 (void)tree_insertnode(&dnsbl_cache, t);
3374 /* Do the DNS lookup . */
3376 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3377 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
3378 cb->text_set = FALSE;
3382 /* If the lookup succeeded, cache the RHS address. The code allows for
3383 more than one address - this was for complete generality and the possible
3384 use of A6 records. However, A6 records have been reduced to experimental
3385 status (August 2001) and may die out. So they may never get used at all,
3386 let alone in dnsbl records. However, leave the code here, just in case.
3388 Quite apart from one A6 RR generating multiple addresses, there are DNS
3389 lists that return more than one A record, so we must handle multiple
3390 addresses generated in that way as well.
3392 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3393 or some suitably far-future time if none were found. */
3395 if (cb->rc == DNS_SUCCEED)
3398 dns_address **addrp = &(cb->rhs);
3399 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3401 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3403 if (rr->type == T_A)
3405 dns_address *da = dns_address_from_rr(&dnsa, rr);
3409 while (da->next != NULL) da = da->next;
3410 addrp = &(da->next);
3411 if (ttl > rr->ttl) ttl = rr->ttl;
3416 /* If we didn't find any A records, change the return code. This can
3417 happen when there is a CNAME record but there are no A records for what
3420 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
3423 cb->expiry = time(NULL)+ttl;
3424 store_pool = old_pool;
3427 /* We now have the result of the DNS lookup, either newly done, or cached
3428 from a previous call. If the lookup succeeded, check against the address
3429 list if there is one. This may be a positive equality list (introduced by
3430 "="), a negative equality list (introduced by "!="), a positive bitmask
3431 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3433 if (cb->rc == DNS_SUCCEED)
3435 dns_address *da = NULL;
3436 uschar *addlist = cb->rhs->address;
3438 /* For A and AAAA records, there may be multiple addresses from multiple
3439 records. For A6 records (currently not expected to be used) there may be
3440 multiple addresses from a single record. */
3442 for (da = cb->rhs->next; da != NULL; da = da->next)
3443 addlist = string_sprintf("%s, %s", addlist, da->address);
3445 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3448 /* Address list check; this can be either for equality, or via a bitmask.
3449 In the latter case, all the bits must match. */
3453 for (da = cb->rhs; da != NULL; da = da->next)
3457 const uschar *ptr = iplist;
3460 /* Handle exact matching */
3464 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3466 if (Ustrcmp(CS da->address, ip) == 0) break;
3470 /* Handle bitmask matching */
3477 /* At present, all known DNS blocking lists use A records, with
3478 IPv4 addresses on the RHS encoding the information they return. I
3479 wonder if this will linger on as the last vestige of IPv4 when IPv6
3480 is ubiquitous? Anyway, for now we use paranoia code to completely
3481 ignore IPv6 addresses. The default mask is 0, which always matches.
3482 We change this only for IPv4 addresses in the list. */
3484 if (host_aton(da->address, address) == 1) mask = address[0];
3486 /* Scan the returned addresses, skipping any that are IPv6 */
3488 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3490 if (host_aton(ip, address) != 1) continue;
3491 if ((address[0] & mask) == address[0]) break;
3497 (a) An IP address in an any ('=') list matched, or
3498 (b) No IP address in an all ('==') list matched
3500 then we're done searching. */
3502 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3505 /* If da == NULL, either
3507 (a) No IP address in an any ('=') list matched, or
3508 (b) An IP address in an all ('==') list didn't match
3510 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3513 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3521 res = US"was no match";
3524 res = US"was an exclude match";
3527 res = US"was an IP address that did not match";
3530 res = US"were no IP addresses that did not match";
3533 debug_printf("=> but we are not accepting this block class because\n");
3534 debug_printf("=> there %s for %s%c%s\n",
3536 ((match_type & MT_ALL) == 0)? "" : "=",
3537 bitmask? '&' : '=', iplist);
3543 /* Either there was no IP list, or the record matched, implying that the
3544 domain is on the list. We now want to find a corresponding TXT record. If an
3545 alternate domain is specified for the TXT record, call this function
3546 recursively to look that up; this has the side effect of re-checking that
3547 there is indeed an A record at the alternate domain. */
3549 if (domain_txt != domain)
3550 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3551 FALSE, match_type, defer_return);
3553 /* If there is no alternate domain, look up a TXT record in the main domain
3554 if it has not previously been cached. */
3558 cb->text_set = TRUE;
3559 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3562 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3564 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3565 if (rr->type == T_TXT) break;
3568 int len = (rr->data)[0];
3569 if (len > 511) len = 127;
3570 store_pool = POOL_PERM;
3571 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3572 store_pool = old_pool;
3577 dnslist_value = addlist;
3578 dnslist_text = cb->text;
3582 /* There was a problem with the DNS lookup */
3584 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3586 log_write(L_dnslist_defer, LOG_MAIN,
3587 "DNS list lookup defer (probably timeout) for %s: %s", query,
3588 (defer_return == OK)? US"assumed in list" :
3589 (defer_return == FAIL)? US"assumed not in list" :
3590 US"returned DEFER");
3591 return defer_return;
3594 /* No entry was found in the DNS; continue for next domain */
3598 debug_printf("DNS lookup for %s failed\n", query);
3599 debug_printf("=> that means %s is not listed at %s\n",
3609 /*************************************************
3610 * Check host against DNS black lists *
3611 *************************************************/
3613 /* This function runs checks against a list of DNS black lists, until one
3614 matches. Each item on the list can be of the form
3616 domain=ip-address/key
3618 The domain is the right-most domain that is used for the query, for example,
3619 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3620 if the DNS lookup returns a matching IP address. Several addresses may be
3621 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3623 If no key is given, what is looked up in the domain is the inverted IP address
3624 of the current client host. If a key is given, it is used to construct the
3625 domain for the lookup. For example:
3627 dsn.rfc-ignorant.org/$sender_address_domain
3629 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3630 then we check for a TXT record for an error message, and if found, save its
3631 value in $dnslist_text. We also cache everything in a tree, to optimize
3634 The TXT record is normally looked up in the same domain as the A record, but
3635 when many lists are combined in a single DNS domain, this will not be a very
3636 specific message. It is possible to specify a different domain for looking up
3637 TXT records; this is given before the main domain, comma-separated. For
3640 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3641 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3643 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3645 Note: an address for testing RBL is 192.203.178.39
3646 Note: an address for testing DUL is 192.203.178.4
3647 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3651 listptr the domain/address/data list
3652 log_msgptr log message on error
3654 Returns: OK successful lookup (i.e. the address is on the list), or
3655 lookup deferred after +include_unknown
3656 FAIL name not found, or no data found for the given type, or
3657 lookup deferred after +exclude_unknown (default)
3658 DEFER lookup failure, if +defer_unknown was set
3662 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3665 int defer_return = FAIL;
3666 const uschar *list = *listptr;
3669 uschar buffer[1024];
3670 uschar revadd[128]; /* Long enough for IPv6 address */
3672 /* Indicate that the inverted IP address is not yet set up */
3676 /* In case this is the first time the DNS resolver is being used. */
3678 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3680 /* Loop through all the domains supplied, until something matches */
3682 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3685 BOOL bitmask = FALSE;
3692 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3694 /* Deal with special values that change the behaviour on defer */
3696 if (domain[0] == '+')
3698 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3699 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3700 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3702 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3707 /* See if there's explicit data to be looked up */
3709 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3711 /* See if there's a list of addresses supplied after the domain name. This is
3712 introduced by an = or a & character; if preceded by = we require all matches
3713 and if preceded by ! we invert the result. */
3715 if (!(iplist = Ustrchr(domain, '=')))
3718 iplist = Ustrchr(domain, '&');
3721 if (iplist) /* Found either = or & */
3723 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3725 match_type |= MT_NOT;
3729 *iplist++ = 0; /* Terminate domain, move on */
3731 /* If we found = (bitmask == FALSE), check for == or =& */
3733 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3735 bitmask = *iplist++ == '&';
3736 match_type |= MT_ALL;
3741 /* If there is a comma in the domain, it indicates that a second domain for
3742 looking up TXT records is provided, before the main domain. Otherwise we must
3743 set domain_txt == domain. */
3745 domain_txt = domain;
3746 comma = Ustrchr(domain, ',');
3753 /* Check that what we have left is a sensible domain name. There is no reason
3754 why these domains should in fact use the same syntax as hosts and email
3755 domains, but in practice they seem to. However, there is little point in
3756 actually causing an error here, because that would no doubt hold up incoming
3757 mail. Instead, I'll just log it. */
3759 for (s = domain; *s != 0; s++)
3761 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3763 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3764 "strange characters - is this right?", domain);
3769 /* Check the alternate domain if present */
3771 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3773 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3775 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3776 "strange characters - is this right?", domain_txt);
3781 /* If there is no key string, construct the query by adding the domain name
3782 onto the inverted host address, and perform a single DNS lookup. */
3786 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3788 *log_msgptr = string_sprintf
3789 ("cannot test auto-keyed dnslists condition in %s ACL",
3790 acl_wherenames[where]);
3793 if (sender_host_address == NULL) return FAIL; /* can never match */
3794 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3795 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3796 iplist, bitmask, match_type, defer_return);
3799 dnslist_domain = string_copy(domain_txt);
3800 dnslist_matched = string_copy(sender_host_address);
3801 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3802 sender_host_address, dnslist_domain);
3804 if (rc != FAIL) return rc; /* OK or DEFER */
3807 /* If there is a key string, it can be a list of domains or IP addresses to
3808 be concatenated with the main domain. */
3815 uschar keybuffer[256];
3816 uschar keyrevadd[128];
3818 while ((keydomain = string_nextinlist(CUSS &key, &keysep, keybuffer,
3819 sizeof(keybuffer))) != NULL)
3821 uschar *prepend = keydomain;
3823 if (string_is_ip_address(keydomain, NULL) != 0)
3825 invert_address(keyrevadd, keydomain);
3826 prepend = keyrevadd;
3829 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3830 bitmask, match_type, defer_return);
3834 dnslist_domain = string_copy(domain_txt);
3835 dnslist_matched = string_copy(keydomain);
3836 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3837 keydomain, dnslist_domain);
3841 /* If the lookup deferred, remember this fact. We keep trying the rest
3842 of the list to see if we get a useful result, and if we don't, we return
3843 DEFER at the end. */
3845 if (rc == DEFER) defer = TRUE;
3846 } /* continue with next keystring domain/address */
3848 if (defer) return DEFER;
3850 } /* continue with next dnsdb outer domain */
3857 /* End of verify.c */