1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2009 */
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). */
14 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
15 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
16 address_item cutthrough_addr;
18 /* Structure for caching DNSBL lookups */
20 typedef struct dnsbl_cache_block {
28 /* Anchor for DNSBL cache */
30 static tree_node *dnsbl_cache = NULL;
33 /* Bits for match_type in one_check_dnsbl() */
40 /*************************************************
41 * Retrieve a callout cache record *
42 *************************************************/
44 /* If a record exists, check whether it has expired.
47 dbm_file an open hints file
49 type "address" or "domain"
50 positive_expire expire time for positive records
51 negative_expire expire time for negative records
53 Returns: the cache record if a non-expired one exists, else NULL
56 static dbdata_callout_cache *
57 get_callout_cache_record(open_db *dbm_file, uschar *key, uschar *type,
58 int positive_expire, int negative_expire)
63 dbdata_callout_cache *cache_record;
65 cache_record = dbfn_read_with_length(dbm_file, key, &length);
67 if (cache_record == NULL)
69 HDEBUG(D_verify) debug_printf("callout cache: no %s record found\n", type);
73 /* We treat a record as "negative" if its result field is not positive, or if
74 it is a domain record and the postmaster field is negative. */
76 negative = cache_record->result != ccache_accept ||
77 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
78 expire = negative? negative_expire : positive_expire;
81 if (now - cache_record->time_stamp > expire)
83 HDEBUG(D_verify) debug_printf("callout cache: %s record expired\n", type);
87 /* If this is a non-reject domain record, check for the obsolete format version
88 that doesn't have the postmaster and random timestamps, by looking at the
89 length. If so, copy it to a new-style block, replicating the record's
90 timestamp. Then check the additional timestamps. (There's no point wasting
91 effort if connections are rejected.) */
93 if (type[0] == 'd' && cache_record->result != ccache_reject)
95 if (length == sizeof(dbdata_callout_cache_obs))
97 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache));
98 memcpy(new, cache_record, length);
99 new->postmaster_stamp = new->random_stamp = new->time_stamp;
103 if (now - cache_record->postmaster_stamp > expire)
104 cache_record->postmaster_result = ccache_unknown;
106 if (now - cache_record->random_stamp > expire)
107 cache_record->random_result = ccache_unknown;
110 HDEBUG(D_verify) debug_printf("callout cache: found %s record\n", type);
116 /*************************************************
117 * Do callout verification for an address *
118 *************************************************/
120 /* This function is called from verify_address() when the address has routed to
121 a host list, and a callout has been requested. Callouts are expensive; that is
122 why a cache is used to improve the efficiency.
125 addr the address that's been routed
126 host_list the list of hosts to try
127 tf the transport feedback block
129 ifstring "interface" option from transport, or NULL
130 portstring "port" option from transport, or NULL
131 protocolstring "protocol" option from transport, or NULL
132 callout the per-command callout timeout
133 callout_overall the overall callout timeout (if < 0 use 4*callout)
134 callout_connect the callout connection timeout (if < 0 use callout)
135 options the verification options - these bits are used:
136 vopt_is_recipient => this is a recipient address
137 vopt_callout_no_cache => don't use callout cache
138 vopt_callout_fullpm => if postmaster check, do full one
139 vopt_callout_random => do the "random" thing
140 vopt_callout_recipsender => use real sender for recipient
141 vopt_callout_recippmaster => use postmaster for recipient
142 se_mailfrom MAIL FROM address for sender verify; NULL => ""
143 pm_mailfrom if non-NULL, do the postmaster check with this sender
145 Returns: OK/FAIL/DEFER
149 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
150 int callout, int callout_overall, int callout_connect, int options,
151 uschar *se_mailfrom, uschar *pm_mailfrom)
153 BOOL is_recipient = (options & vopt_is_recipient) != 0;
154 BOOL callout_no_cache = (options & vopt_callout_no_cache) != 0;
155 BOOL callout_random = (options & vopt_callout_random) != 0;
158 int old_domain_cache_result = ccache_accept;
161 uschar *from_address;
162 uschar *random_local_part = NULL;
163 uschar *save_deliver_domain = deliver_domain;
164 uschar **failure_ptr = is_recipient?
165 &recipient_verify_failure : &sender_verify_failure;
167 open_db *dbm_file = NULL;
168 dbdata_callout_cache new_domain_record;
169 dbdata_callout_cache_address new_address_record;
171 time_t callout_start_time;
173 new_domain_record.result = ccache_unknown;
174 new_domain_record.postmaster_result = ccache_unknown;
175 new_domain_record.random_result = ccache_unknown;
177 memset(&new_address_record, 0, sizeof(new_address_record));
179 /* For a recipient callout, the key used for the address cache record must
180 include the sender address if we are using the real sender in the callout,
181 because that may influence the result of the callout. */
183 address_key = addr->address;
188 if ((options & vopt_callout_recipsender) != 0)
190 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
191 from_address = sender_address;
193 else if ((options & vopt_callout_recippmaster) != 0)
195 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
196 qualify_domain_sender);
197 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
201 /* For a sender callout, we must adjust the key if the mailfrom address is not
206 from_address = (se_mailfrom == NULL)? US"" : se_mailfrom;
207 if (from_address[0] != 0)
208 address_key = string_sprintf("%s/<%s>", addr->address, from_address);
211 /* Open the callout cache database, it it exists, for reading only at this
212 stage, unless caching has been disabled. */
214 if (callout_no_cache)
216 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
218 else if ((dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE)) == NULL)
220 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
223 /* If a cache database is available see if we can avoid the need to do an
224 actual callout by making use of previously-obtained data. */
226 if (dbm_file != NULL)
228 dbdata_callout_cache_address *cache_address_record;
229 dbdata_callout_cache *cache_record = get_callout_cache_record(dbm_file,
230 addr->domain, US"domain",
231 callout_cache_domain_positive_expire,
232 callout_cache_domain_negative_expire);
234 /* If an unexpired cache record was found for this domain, see if the callout
235 process can be short-circuited. */
237 if (cache_record != NULL)
239 /* In most cases, if an early command (up to and including MAIL FROM:<>)
240 was rejected, there is no point carrying on. The callout fails. However, if
241 we are doing a recipient verification with use_sender or use_postmaster
242 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
243 will be using a non-empty sender. We have to remember this situation so as
244 not to disturb the cached domain value if this whole verification succeeds
245 (we don't want it turning into "accept"). */
247 old_domain_cache_result = cache_record->result;
249 if (cache_record->result == ccache_reject ||
250 (*from_address == 0 && cache_record->result == ccache_reject_mfnull))
252 setflag(addr, af_verify_nsfail);
254 debug_printf("callout cache: domain gave initial rejection, or "
255 "does not accept HELO or MAIL FROM:<>\n");
256 setflag(addr, af_verify_nsfail);
257 addr->user_message = US"(result of an earlier callout reused).";
259 *failure_ptr = US"mail";
263 /* If a previous check on a "random" local part was accepted, we assume
264 that the server does not do any checking on local parts. There is therefore
265 no point in doing the callout, because it will always be successful. If a
266 random check previously failed, arrange not to do it again, but preserve
267 the data in the new record. If a random check is required but hasn't been
268 done, skip the remaining cache processing. */
270 if (callout_random) switch(cache_record->random_result)
274 debug_printf("callout cache: domain accepts random addresses\n");
275 goto END_CALLOUT; /* Default yield is OK */
279 debug_printf("callout cache: domain rejects random addresses\n");
280 callout_random = FALSE;
281 new_domain_record.random_result = ccache_reject;
282 new_domain_record.random_stamp = cache_record->random_stamp;
287 debug_printf("callout cache: need to check random address handling "
288 "(not cached or cache expired)\n");
292 /* If a postmaster check is requested, but there was a previous failure,
293 there is again no point in carrying on. If a postmaster check is required,
294 but has not been done before, we are going to have to do a callout, so skip
295 remaining cache processing. */
297 if (pm_mailfrom != NULL)
299 if (cache_record->postmaster_result == ccache_reject)
301 setflag(addr, af_verify_pmfail);
303 debug_printf("callout cache: domain does not accept "
304 "RCPT TO:<postmaster@domain>\n");
306 *failure_ptr = US"postmaster";
307 setflag(addr, af_verify_pmfail);
308 addr->user_message = US"(result of earlier verification reused).";
311 if (cache_record->postmaster_result == ccache_unknown)
314 debug_printf("callout cache: need to check RCPT "
315 "TO:<postmaster@domain> (not cached or cache expired)\n");
319 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
320 postmaster check if the address itself has to be checked. Also ensure
321 that the value in the cache record is preserved (with its old timestamp).
324 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
325 "TO:<postmaster@domain>\n");
327 new_domain_record.postmaster_result = ccache_accept;
328 new_domain_record.postmaster_stamp = cache_record->postmaster_stamp;
332 /* We can't give a result based on information about the domain. See if there
333 is an unexpired cache record for this specific address (combined with the
334 sender address if we are doing a recipient callout with a non-empty sender).
337 cache_address_record = (dbdata_callout_cache_address *)
338 get_callout_cache_record(dbm_file,
339 address_key, US"address",
340 callout_cache_positive_expire,
341 callout_cache_negative_expire);
343 if (cache_address_record != NULL)
345 if (cache_address_record->result == ccache_accept)
348 debug_printf("callout cache: address record is positive\n");
353 debug_printf("callout cache: address record is negative\n");
354 addr->user_message = US"Previous (cached) callout verification failure";
355 *failure_ptr = US"recipient";
361 /* Close the cache database while we actually do the callout for real. */
364 dbfn_close(dbm_file);
368 /* The information wasn't available in the cache, so we have to do a real
369 callout and save the result in the cache for next time, unless no_cache is set,
370 or unless we have a previously cached negative random result. If we are to test
371 with a random local part, ensure that such a local part is available. If not,
372 log the fact, but carry on without randomming. */
374 if (callout_random && callout_random_local_part != NULL)
376 random_local_part = expand_string(callout_random_local_part);
377 if (random_local_part == NULL)
378 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
379 "callout_random_local_part: %s", expand_string_message);
382 /* Default the connect and overall callout timeouts if not set, and record the
383 time we are starting so that we can enforce it. */
385 if (callout_overall < 0) callout_overall = 4 * callout;
386 if (callout_connect < 0) callout_connect = callout;
387 callout_start_time = time(NULL);
389 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
390 output because a callout might take some time. When PIPELINING is active and
391 there are many recipients, the total time for doing lots of callouts can add up
392 and cause the client to time out. So in this case we forgo the PIPELINING
395 if (smtp_out != NULL && !disable_callout_flush) mac_smtp_fflush();
397 /* Now make connections to the hosts and do real callouts. The list of hosts
398 is passed in as an argument. */
400 for (host = host_list; host != NULL && !done; host = host->next)
402 smtp_inblock inblock;
403 smtp_outblock outblock;
406 BOOL send_quit = TRUE;
407 uschar *active_hostname = smtp_active_hostname;
408 uschar *helo = US"HELO";
409 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
410 uschar inbuffer[4096];
411 uschar outbuffer[1024];
412 uschar responsebuffer[4096];
414 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
415 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
417 /* Skip this host if we don't have an IP address for it. */
419 if (host->address == NULL)
421 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
426 /* Check the overall callout timeout */
428 if (time(NULL) - callout_start_time >= callout_overall)
430 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
434 /* Set IPv4 or IPv6 */
436 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET:AF_INET6;
438 /* Expand and interpret the interface and port strings. The latter will not
439 be used if there is a host-specific port (e.g. from a manualroute router).
440 This has to be delayed till now, because they may expand differently for
441 different hosts. If there's a failure, log it, but carry on with the
444 deliver_host = host->name;
445 deliver_host_address = host->address;
446 deliver_domain = addr->domain;
448 if (!smtp_get_interface(tf->interface, host_af, addr, NULL, &interface,
450 !smtp_get_port(tf->port, addr, &port, US"callout"))
451 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
454 /* Set HELO string according to the protocol */
456 if (Ustrcmp(tf->protocol, "lmtp") == 0) helo = US"LHLO";
458 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", interface, port);
460 /* Set up the buffer for reading SMTP response packets. */
462 inblock.buffer = inbuffer;
463 inblock.buffersize = sizeof(inbuffer);
464 inblock.ptr = inbuffer;
465 inblock.ptrend = inbuffer;
467 /* Set up the buffer for holding SMTP commands while pipelining */
469 outblock.buffer = outbuffer;
470 outblock.buffersize = sizeof(outbuffer);
471 outblock.ptr = outbuffer;
472 outblock.cmd_count = 0;
473 outblock.authenticating = FALSE;
475 /* Connect to the host; on failure, just loop for the next one, but we
476 set the error for the last one. Use the callout_connect timeout. */
478 inblock.sock = outblock.sock =
479 smtp_connect(host, host_af, port, interface, callout_connect, TRUE, NULL);
480 /* reconsider DSCP here */
481 if (inblock.sock < 0)
483 addr->message = string_sprintf("could not connect to %s [%s]: %s",
484 host->name, host->address, strerror(errno));
485 deliver_host = deliver_host_address = NULL;
486 deliver_domain = save_deliver_domain;
490 /* Expand the helo_data string to find the host name to use. */
492 if (tf->helo_data != NULL)
494 uschar *s = expand_string(tf->helo_data);
496 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: failed to expand transport's "
497 "helo_data value for callout: %s", addr->address,
498 expand_string_message);
499 else active_hostname = s;
502 deliver_host = deliver_host_address = NULL;
503 deliver_domain = save_deliver_domain;
505 /* Wait for initial response, and send HELO. The smtp_write_command()
506 function leaves its command in big_buffer. This is used in error responses.
507 Initialize it in case the connection is rejected. */
509 Ustrcpy(big_buffer, "initial connection");
512 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
514 smtp_write_command(&outblock, FALSE, "%s %s\r\n", helo,
515 active_hostname) >= 0 &&
516 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
519 /* Failure to accept HELO is cached; this blocks the whole domain for all
520 senders. I/O errors and defer responses are not cached. */
524 *failure_ptr = US"mail"; /* At or before MAIL */
525 if (errno == 0 && responsebuffer[0] == '5')
527 setflag(addr, af_verify_nsfail);
528 new_domain_record.result = ccache_reject;
532 /* Send the MAIL command */
535 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
536 from_address) >= 0 &&
537 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
540 /* If the host does not accept MAIL FROM:<>, arrange to cache this
541 information, but again, don't record anything for an I/O error or a defer. Do
542 not cache rejections of MAIL when a non-empty sender has been used, because
543 that blocks the whole domain for all senders. */
547 *failure_ptr = US"mail"; /* At or before MAIL */
548 if (errno == 0 && responsebuffer[0] == '5')
550 setflag(addr, af_verify_nsfail);
551 if (from_address[0] == 0)
552 new_domain_record.result = ccache_reject_mfnull;
556 /* Otherwise, proceed to check a "random" address (if required), then the
557 given address, and the postmaster address (if required). Between each check,
558 issue RSET, because some servers accept only one recipient after MAIL
561 Before doing this, set the result in the domain cache record to "accept",
562 unless its previous value was ccache_reject_mfnull. In that case, the domain
563 rejects MAIL FROM:<> and we want to continue to remember that. When that is
564 the case, we have got here only in the case of a recipient verification with
565 a non-null sender. */
569 new_domain_record.result =
570 (old_domain_cache_result == ccache_reject_mfnull)?
571 ccache_reject_mfnull: ccache_accept;
573 /* Do the random local part check first */
575 if (random_local_part != NULL)
577 uschar randombuffer[1024];
579 smtp_write_command(&outblock, FALSE,
580 "RCPT TO:<%.1000s@%.1000s>\r\n", random_local_part,
581 addr->domain) >= 0 &&
582 smtp_read_response(&inblock, randombuffer,
583 sizeof(randombuffer), '2', callout);
585 /* Remember when we last did a random test */
587 new_domain_record.random_stamp = time(NULL);
589 /* If accepted, we aren't going to do any further tests below. */
593 new_domain_record.random_result = ccache_accept;
596 /* Otherwise, cache a real negative response, and get back to the right
597 state to send RCPT. Unless there's some problem such as a dropped
598 connection, we expect to succeed, because the commands succeeded above. */
602 if (randombuffer[0] == '5')
603 new_domain_record.random_result = ccache_reject;
606 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
607 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
610 smtp_write_command(&outblock, FALSE, "MAIL FROM:<%s>\r\n",
611 from_address) >= 0 &&
612 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
615 else done = FALSE; /* Some timeout/connection problem */
618 /* If the host is accepting all local parts, as determined by the "random"
619 check, we don't need to waste time doing any further checking. */
621 if (new_domain_record.random_result != ccache_accept && done)
623 /* Get the rcpt_include_affixes flag from the transport if there is one,
624 but assume FALSE if there is not. */
627 smtp_write_command(&outblock, FALSE, "RCPT TO:<%.1000s>\r\n",
628 transport_rcpt_address(addr,
629 (addr->transport == NULL)? FALSE :
630 addr->transport->rcpt_include_affixes)) >= 0 &&
631 smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer),
635 new_address_record.result = ccache_accept;
636 else if (errno == 0 && responsebuffer[0] == '5')
638 *failure_ptr = US"recipient";
639 new_address_record.result = ccache_reject;
642 /* Do postmaster check if requested; if a full check is required, we
643 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
645 if (done && pm_mailfrom != NULL)
647 /*XXX not suitable for cutthrough - sequencing problems */
648 cutthrough_delivery= FALSE;
651 smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0 &&
652 smtp_read_response(&inblock, responsebuffer,
653 sizeof(responsebuffer), '2', callout) &&
655 smtp_write_command(&outblock, FALSE,
656 "MAIL FROM:<%s>\r\n", pm_mailfrom) >= 0 &&
657 smtp_read_response(&inblock, responsebuffer,
658 sizeof(responsebuffer), '2', callout) &&
660 /* First try using the current domain */
663 smtp_write_command(&outblock, FALSE,
664 "RCPT TO:<postmaster@%.1000s>\r\n", addr->domain) >= 0 &&
665 smtp_read_response(&inblock, responsebuffer,
666 sizeof(responsebuffer), '2', callout)
671 /* If that doesn't work, and a full check is requested,
672 try without the domain. */
675 (options & vopt_callout_fullpm) != 0 &&
676 smtp_write_command(&outblock, FALSE,
677 "RCPT TO:<postmaster>\r\n") >= 0 &&
678 smtp_read_response(&inblock, responsebuffer,
679 sizeof(responsebuffer), '2', callout)
682 /* Sort out the cache record */
684 new_domain_record.postmaster_stamp = time(NULL);
687 new_domain_record.postmaster_result = ccache_accept;
688 else if (errno == 0 && responsebuffer[0] == '5')
690 *failure_ptr = US"postmaster";
691 setflag(addr, af_verify_pmfail);
692 new_domain_record.postmaster_result = ccache_reject;
695 } /* Random not accepted */
696 } /* MAIL FROM: accepted */
698 /* For any failure of the main check, other than a negative response, we just
699 close the connection and carry on. We can identify a negative response by the
700 fact that errno is zero. For I/O errors it will be non-zero
702 Set up different error texts for logging and for sending back to the caller
703 as an SMTP response. Log in all cases, using a one-line format. For sender
704 callouts, give a full response to the caller, but for recipient callouts,
705 don't give the IP address because this may be an internal host whose identity
706 is not to be widely broadcast. */
710 if (errno == ETIMEDOUT)
712 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
717 if (*responsebuffer == 0) Ustrcpy(responsebuffer, US"connection dropped");
720 string_sprintf("response to \"%s\" from %s [%s] was: %s",
721 big_buffer, host->name, host->address,
722 string_printing(responsebuffer));
724 addr->user_message = is_recipient?
725 string_sprintf("Callout verification failed:\n%s", responsebuffer)
727 string_sprintf("Called: %s\nSent: %s\nResponse: %s",
728 host->address, big_buffer, responsebuffer);
730 /* Hard rejection ends the process */
732 if (responsebuffer[0] == '5') /* Address rejected */
740 /* End the SMTP conversation and close the connection. */
742 /*XXX cutthrough - if "done"
744 and we have no cutthrough conn so far
745 here is where we want to leave the conn open */
746 /* and leave some form of marker for it */
747 /*XXX in fact for simplicity we should abandon cutthrough as soon as more than one address
749 /*XXX what about TLS? */
750 if ( cutthrough_delivery
754 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster)) == vopt_callout_recipsender
755 && !random_local_part
759 cutthrough_fd= outblock.sock; /* We assume no buffer in use in the outblock */
760 cutthrough_addr= *addr; /* Save the address_item for later logging */
764 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
765 (void)close(inblock.sock);
768 } /* Loop through all hosts, while !done */
770 /* If we get here with done == TRUE, a successful callout happened, and yield
771 will be set OK or FAIL according to the response to the RCPT command.
772 Otherwise, we looped through the hosts but couldn't complete the business.
773 However, there may be domain-specific information to cache in both cases.
775 The value of the result field in the new_domain record is ccache_unknown if
776 there was an error before or with MAIL FROM:, and errno was not zero,
777 implying some kind of I/O error. We don't want to write the cache in that case.
778 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
780 if (!callout_no_cache && new_domain_record.result != ccache_unknown)
782 if ((dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE))
785 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
789 (void)dbfn_write(dbm_file, addr->domain, &new_domain_record,
790 (int)sizeof(dbdata_callout_cache));
791 HDEBUG(D_verify) debug_printf("wrote callout cache domain record:\n"
792 " result=%d postmaster=%d random=%d\n",
793 new_domain_record.result,
794 new_domain_record.postmaster_result,
795 new_domain_record.random_result);
799 /* If a definite result was obtained for the callout, cache it unless caching
804 if (!callout_no_cache && new_address_record.result != ccache_unknown)
806 if (dbm_file == NULL)
807 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE);
808 if (dbm_file == NULL)
810 HDEBUG(D_verify) debug_printf("no callout cache available\n");
814 (void)dbfn_write(dbm_file, address_key, &new_address_record,
815 (int)sizeof(dbdata_callout_cache_address));
816 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record\n",
817 (new_address_record.result == ccache_accept)? "positive" : "negative");
822 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
823 temporary error. If there was only one host, and a response was received, leave
824 it alone if supplying details. Otherwise, give a generic response. */
828 uschar *dullmsg = string_sprintf("Could not complete %s verify callout",
829 is_recipient? "recipient" : "sender");
832 if (host_list->next != NULL || addr->message == NULL) addr->message = dullmsg;
834 addr->user_message = (!smtp_return_error_details)? dullmsg :
835 string_sprintf("%s for <%s>.\n"
836 "The mail server(s) for the domain may be temporarily unreachable, or\n"
837 "they may be permanently unreachable from this server. In the latter case,\n%s",
838 dullmsg, addr->address,
840 "the address will never be accepted."
842 "you need to change the address or create an MX record for its domain\n"
843 "if it is supposed to be generally accessible from the Internet.\n"
844 "Talk to your mail administrator for details.");
846 /* Force a specific error code */
848 addr->basic_errno = ERRNO_CALLOUTDEFER;
851 /* Come here from within the cache-reading code on fast-track exit. */
854 if (dbm_file != NULL) dbfn_close(dbm_file);
861 open_cutthrough_connection( address_item * addr )
865 /* Use a recipient-verify-callout to set up the cutthrough connection. */
866 /* We must use a copy of the address for verification, because it might
870 HDEBUG(D_acl) debug_printf("----------- start cutthrough setup ------------\n");
871 (void) verify_address(&addr2, NULL,
872 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
873 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
875 HDEBUG(D_acl) debug_printf("----------- end cutthrough setup ------------\n");
880 static smtp_outblock ctblock;
881 uschar ctbuffer[8192];
885 cancel_cutthrough_connection( void )
887 ctblock.ptr = ctbuffer;
888 cutthrough_delivery= FALSE;
889 if(cutthrough_fd >= 0) /*XXX get that initialised, also at RSET */
893 /* We could be sending this after a bunch of data, but that is ok as
894 the only way to cancel the transfer in dataphase is to drop the tcp
895 conn before the final dot.
897 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> QUIT\n");
898 rc= send(cutthrough_fd, "QUIT\r\n", 6, 0);
899 /*XXX error handling? TLS? See flush_buffer() in smtp_out.c */
901 (void)close(cutthrough_fd);
903 HDEBUG(D_acl) debug_printf("----------- cutthrough shutdown ------------\n");
909 /* Buffered output counted data block. Return boolean success */
911 cutthrough_puts(uschar * cp, int n)
913 if(cutthrough_fd >= 0)
916 /*XXX TLS? See flush_buffer() in smtp_out.c */
918 if(ctblock.ptr >= ctblock.buffer+ctblock.buffersize)
920 if(send(cutthrough_fd, ctblock.buffer, ctblock.buffersize, 0) < 0)
922 transport_count += ctblock.buffersize;
923 ctblock.ptr= ctblock.buffer;
926 *ctblock.ptr++ = *cp++;
931 cancel_cutthrough_connection();
936 cutthrough_flush_send( void )
938 if(cutthrough_fd >= 0)
940 if(send(cutthrough_fd, ctblock.buffer, ctblock.ptr-ctblock.buffer, 0) < 0)
942 transport_count += ctblock.ptr-ctblock.buffer;
943 ctblock.ptr= ctblock.buffer;
948 cancel_cutthrough_connection();
954 cutthrough_put_nl( void )
956 return cutthrough_puts(US"\r\n", 2);
960 /* Get and check response from cutthrough target */
962 cutthrough_response(char expect, uschar ** copy)
964 smtp_inblock inblock;
965 uschar inbuffer[4096];
966 uschar responsebuffer[4096];
968 inblock.buffer = inbuffer;
969 inblock.buffersize = sizeof(inbuffer);
970 inblock.ptr = inbuffer;
971 inblock.ptrend = inbuffer;
972 inblock.sock = cutthrough_fd;
973 if(!smtp_read_response(&inblock, responsebuffer, sizeof(responsebuffer), expect, CUTTHROUGH_DATA_TIMEOUT))
974 cancel_cutthrough_connection();
979 *copy= cp= string_copy(responsebuffer);
980 /* Trim the trailing end of line */
981 cp += Ustrlen(responsebuffer);
982 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
983 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
986 return responsebuffer[0];
990 /* Negotiate dataphase with the cutthrough target, returning success boolean */
992 cutthrough_predata( void )
996 if(cutthrough_fd < 0)
999 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> DATA\n");
1000 rc= send(cutthrough_fd, "DATA\r\n", 6, 0);
1003 HDEBUG(D_transport|D_acl) debug_printf("send failed: %s\n", strerror(errno));
1004 cancel_cutthrough_connection();
1007 /*XXX error handling? TLS? See flush_buffer() in smtp_out.c */
1009 /* Assume nothing buffered. If it was it gets ignored. */
1010 return cutthrough_response('3', NULL) == '3';
1014 /* Buffered send of headers. Return success boolean. */
1015 /* Also sends header-terminating blank line. */
1016 /* Sets up the "ctblock" buffer as a side-effect. */
1018 cutthrough_headers_send( void )
1022 if(cutthrough_fd < 0)
1025 ctblock.buffer = ctbuffer;
1026 ctblock.buffersize = sizeof(ctbuffer);
1027 ctblock.ptr = ctbuffer;
1028 /* ctblock.cmd_count = 0; ctblock.authenticating = FALSE; */
1029 ctblock.sock = cutthrough_fd;
1031 for(h= header_list; h != NULL; h= h->next)
1032 if(h->type != htype_old && h->text != NULL)
1033 if(!cutthrough_puts(h->text, h->slen))
1036 if(!cutthrough_put_nl())
1041 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1042 Log an OK response as a transmission.
1043 Return smtp response-class digit.
1044 XXX where do fail responses from target get logged?
1047 cutthrough_finaldot( void )
1049 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> .\n");
1051 /* Assume data finshed with new-line */
1052 if(!cutthrough_puts(US".", 1) || !cutthrough_put_nl()
1053 || !cutthrough_flush_send()
1054 || cutthrough_response('2', &cutthrough_addr.message) != '2')
1055 return cutthrough_addr.message;
1057 (void)close(cutthrough_fd);
1059 HDEBUG(D_acl) debug_printf("----------- cutthrough close ------------\n");
1061 delivery_log(&cutthrough_addr, (int)'>');
1065 /* delivery S= zero! (transport_count) */
1066 /* not TLS yet hence no X, CV, DN */
1068 return cutthrough_addr.message;
1072 /*************************************************
1073 * Copy error to toplevel address *
1074 *************************************************/
1076 /* This function is used when a verify fails or defers, to ensure that the
1077 failure or defer information is in the original toplevel address. This applies
1078 when an address is redirected to a single new address, and the failure or
1079 deferral happens to the child address.
1082 vaddr the verify address item
1083 addr the final address item
1086 Returns: the value of YIELD
1090 copy_error(address_item *vaddr, address_item *addr, int yield)
1094 vaddr->message = addr->message;
1095 vaddr->user_message = addr->user_message;
1096 vaddr->basic_errno = addr->basic_errno;
1097 vaddr->more_errno = addr->more_errno;
1098 vaddr->p.address_data = addr->p.address_data;
1099 copyflag(vaddr, addr, af_pass_message);
1107 /**************************************************
1108 * printf that automatically handles TLS if needed *
1109 ***************************************************/
1111 /* This function is used by verify_address() as a substitute for all fprintf()
1112 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1113 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1114 that assumes that we always use the smtp_out FILE* when not using TLS or the
1115 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1116 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1120 f the candidate FILE* to write to
1121 format format string
1122 ... optional arguments
1128 static void PRINTF_FUNCTION(2,3)
1129 respond_printf(FILE *f, const char *format, ...)
1133 va_start(ap, format);
1134 if (smtp_out && (f == smtp_out))
1135 smtp_vprintf(format, ap);
1137 vfprintf(f, format, ap);
1143 /*************************************************
1144 * Verify an email address *
1145 *************************************************/
1147 /* This function is used both for verification (-bv and at other times) and
1148 address testing (-bt), which is indicated by address_test_mode being set.
1151 vaddr contains the address to verify; the next field in this block
1153 f if not NULL, write the result to this file
1154 options various option bits:
1155 vopt_fake_sender => this sender verify is not for the real
1156 sender (it was verify=sender=xxxx or an address from a
1157 header line) - rewriting must not change sender_address
1158 vopt_is_recipient => this is a recipient address, otherwise
1159 it's a sender address - this affects qualification and
1160 rewriting and messages from callouts
1161 vopt_qualify => qualify an unqualified address; else error
1162 vopt_expn => called from SMTP EXPN command
1163 vopt_success_on_redirect => when a new address is generated
1164 the verification instantly succeeds
1166 These ones are used by do_callout() -- the options variable
1169 vopt_callout_fullpm => if postmaster check, do full one
1170 vopt_callout_no_cache => don't use callout cache
1171 vopt_callout_random => do the "random" thing
1172 vopt_callout_recipsender => use real sender for recipient
1173 vopt_callout_recippmaster => use postmaster for recipient
1175 callout if > 0, specifies that callout is required, and gives timeout
1176 for individual commands
1177 callout_overall if > 0, gives overall timeout for the callout function;
1178 if < 0, a default is used (see do_callout())
1179 callout_connect the connection timeout for callouts
1180 se_mailfrom when callout is requested to verify a sender, use this
1181 in MAIL FROM; NULL => ""
1182 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1183 thing and use this as the sender address (may be "")
1185 routed if not NULL, set TRUE if routing succeeded, so we can
1186 distinguish between routing failed and callout failed
1188 Returns: OK address verified
1189 FAIL address failed to verify
1190 DEFER can't tell at present
1194 verify_address(address_item *vaddr, FILE *f, int options, int callout,
1195 int callout_overall, int callout_connect, uschar *se_mailfrom,
1196 uschar *pm_mailfrom, BOOL *routed)
1199 BOOL full_info = (f == NULL)? FALSE : (debug_selector != 0);
1200 BOOL is_recipient = (options & vopt_is_recipient) != 0;
1201 BOOL expn = (options & vopt_expn) != 0;
1202 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1205 int verify_type = expn? v_expn :
1206 address_test_mode? v_none :
1207 is_recipient? v_recipient : v_sender;
1208 address_item *addr_list;
1209 address_item *addr_new = NULL;
1210 address_item *addr_remote = NULL;
1211 address_item *addr_local = NULL;
1212 address_item *addr_succeed = NULL;
1213 uschar **failure_ptr = is_recipient?
1214 &recipient_verify_failure : &sender_verify_failure;
1215 uschar *ko_prefix, *cr;
1216 uschar *address = vaddr->address;
1217 uschar *save_sender;
1218 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1220 /* Clear, just in case */
1222 *failure_ptr = NULL;
1224 /* Set up a prefix and suffix for error message which allow us to use the same
1225 output statements both in EXPN mode (where an SMTP response is needed) and when
1226 debugging with an output file. */
1230 ko_prefix = US"553 ";
1233 else ko_prefix = cr = US"";
1235 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1237 if (parse_find_at(address) == NULL)
1239 if ((options & vopt_qualify) == 0)
1242 respond_printf(f, "%sA domain is required for \"%s\"%s\n",
1243 ko_prefix, address, cr);
1244 *failure_ptr = US"qualify";
1247 address = rewrite_address_qualify(address, is_recipient);
1252 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1253 debug_printf("%s %s\n", address_test_mode? "Testing" : "Verifying", address);
1256 /* Rewrite and report on it. Clear the domain and local part caches - these
1257 may have been set by domains and local part tests during an ACL. */
1259 if (global_rewrite_rules != NULL)
1261 uschar *old = address;
1262 address = rewrite_address(address, is_recipient, FALSE,
1263 global_rewrite_rules, rewrite_existflags);
1266 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1267 for (i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1268 if (f != NULL && !expn) fprintf(f, "Address rewritten as: %s\n", address);
1272 /* If this is the real sender address, we must update sender_address at
1273 this point, because it may be referred to in the routers. */
1275 if ((options & (vopt_fake_sender|vopt_is_recipient)) == 0)
1276 sender_address = address;
1278 /* If the address was rewritten to <> no verification can be done, and we have
1279 to return OK. This rewriting is permitted only for sender addresses; for other
1280 addresses, such rewriting fails. */
1282 if (address[0] == 0) return OK;
1284 /* Save a copy of the sender address for re-instating if we change it to <>
1285 while verifying a sender address (a nice bit of self-reference there). */
1287 save_sender = sender_address;
1289 /* Update the address structure with the possibly qualified and rewritten
1290 address. Set it up as the starting address on the chain of new addresses. */
1292 vaddr->address = address;
1295 /* We need a loop, because an address can generate new addresses. We must also
1296 cope with generated pipes and files at the top level. (See also the code and
1297 comment in deliver.c.) However, it is usually the case that the router for
1298 user's .forward files has its verify flag turned off.
1300 If an address generates more than one child, the loop is used only when
1301 full_info is set, and this can only be set locally. Remote enquiries just get
1302 information about the top level address, not anything that it generated. */
1304 while (addr_new != NULL)
1307 address_item *addr = addr_new;
1309 addr_new = addr->next;
1314 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1315 debug_printf("Considering %s\n", addr->address);
1318 /* Handle generated pipe, file or reply addresses. We don't get these
1319 when handling EXPN, as it does only one level of expansion. */
1321 if (testflag(addr, af_pfr))
1328 if (addr->address[0] == '>')
1330 allow = testflag(addr, af_allow_reply);
1331 fprintf(f, "%s -> mail %s", addr->parent->address, addr->address + 1);
1335 allow = (addr->address[0] == '|')?
1336 testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1337 fprintf(f, "%s -> %s", addr->parent->address, addr->address);
1340 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1341 fprintf(f, "\n*** Error in setting up pipe, file, or autoreply:\n"
1342 "%s\n", addr->message);
1344 fprintf(f, "\n transport = %s\n", addr->transport->name);
1346 fprintf(f, " *** forbidden ***\n");
1351 /* Just in case some router parameter refers to it. */
1353 return_path = (addr->p.errors_address != NULL)?
1354 addr->p.errors_address : sender_address;
1356 /* Split the address into domain and local part, handling the %-hack if
1357 necessary, and then route it. While routing a sender address, set
1358 $sender_address to <> because that is what it will be if we were trying to
1359 send a bounce to the sender. */
1361 if (routed != NULL) *routed = FALSE;
1362 if ((rc = deliver_split_address(addr)) == OK)
1364 if (!is_recipient) sender_address = null_sender;
1365 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1366 &addr_succeed, verify_type);
1367 sender_address = save_sender; /* Put back the real sender */
1370 /* If routing an address succeeded, set the flag that remembers, for use when
1371 an ACL cached a sender verify (in case a callout fails). Then if routing set
1372 up a list of hosts or the transport has a host list, and the callout option
1373 is set, and we aren't in a host checking run, do the callout verification,
1374 and set another flag that notes that a callout happened. */
1378 if (routed != NULL) *routed = TRUE;
1381 host_item *host_list = addr->host_list;
1383 /* Make up some data for use in the case where there is no remote
1386 transport_feedback tf = {
1387 NULL, /* interface (=> any) */
1388 US"smtp", /* port */
1389 US"smtp", /* protocol */
1391 US"$smtp_active_hostname", /* helo_data */
1392 FALSE, /* hosts_override */
1393 FALSE, /* hosts_randomize */
1394 FALSE, /* gethostbyname */
1395 TRUE, /* qualify_single */
1396 FALSE /* search_parents */
1399 /* If verification yielded a remote transport, we want to use that
1400 transport's options, so as to mimic what would happen if we were really
1401 sending a message to this address. */
1403 if (addr->transport != NULL && !addr->transport->info->local)
1405 (void)(addr->transport->setup)(addr->transport, addr, &tf, 0, 0, NULL);
1407 /* If the transport has hosts and the router does not, or if the
1408 transport is configured to override the router's hosts, we must build a
1409 host list of the transport's hosts, and find the IP addresses */
1411 if (tf.hosts != NULL && (host_list == NULL || tf.hosts_override))
1414 uschar *save_deliver_domain = deliver_domain;
1415 uschar *save_deliver_localpart = deliver_localpart;
1417 host_list = NULL; /* Ignore the router's hosts */
1419 deliver_domain = addr->domain;
1420 deliver_localpart = addr->local_part;
1421 s = expand_string(tf.hosts);
1422 deliver_domain = save_deliver_domain;
1423 deliver_localpart = save_deliver_localpart;
1427 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1428 "\"%s\" in %s transport for callout: %s", tf.hosts,
1429 addr->transport->name, expand_string_message);
1434 uschar *canonical_name;
1435 host_item *host, *nexthost;
1436 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1438 /* Just ignore failures to find a host address. If we don't manage
1439 to find any addresses, the callout will defer. Note that more than
1440 one address may be found for a single host, which will result in
1441 additional host items being inserted into the chain. Hence we must
1442 save the next host first. */
1444 flags = HOST_FIND_BY_A;
1445 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1446 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1448 for (host = host_list; host != NULL; host = nexthost)
1450 nexthost = host->next;
1451 if (tf.gethostbyname ||
1452 string_is_ip_address(host->name, NULL) != 0)
1453 (void)host_find_byname(host, NULL, flags, &canonical_name, TRUE);
1455 (void)host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1456 &canonical_name, NULL);
1462 /* Can only do a callout if we have at least one host! If the callout
1463 fails, it will have set ${sender,recipient}_verify_failure. */
1465 if (host_list != NULL)
1467 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1468 if (host_checking && !host_checking_callout)
1471 debug_printf("... callout omitted by default when host testing\n"
1472 "(Use -bhc if you want the callouts to happen.)\n");
1476 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1477 callout_connect, options, se_mailfrom, pm_mailfrom);
1482 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1483 "transport provided a host list\n");
1488 /* Otherwise, any failure is a routing failure */
1490 else *failure_ptr = US"route";
1492 /* A router may return REROUTED if it has set up a child address as a result
1493 of a change of domain name (typically from widening). In this case we always
1494 want to continue to verify the new child. */
1496 if (rc == REROUTED) continue;
1498 /* Handle hard failures */
1505 address_item *p = addr->parent;
1507 respond_printf(f, "%s%s %s", ko_prefix,
1508 full_info? addr->address : address,
1509 address_test_mode? "is undeliverable" : "failed to verify");
1510 if (!expn && admin_user)
1512 if (addr->basic_errno > 0)
1513 respond_printf(f, ": %s", strerror(addr->basic_errno));
1514 if (addr->message != NULL)
1515 respond_printf(f, ": %s", addr->message);
1518 /* Show parents iff doing full info */
1520 if (full_info) while (p != NULL)
1522 respond_printf(f, "%s\n <-- %s", cr, p->address);
1525 respond_printf(f, "%s\n", cr);
1527 cancel_cutthrough_connection();
1529 if (!full_info) return copy_error(vaddr, addr, FAIL);
1535 else if (rc == DEFER)
1540 address_item *p = addr->parent;
1541 respond_printf(f, "%s%s cannot be resolved at this time", ko_prefix,
1542 full_info? addr->address : address);
1543 if (!expn && admin_user)
1545 if (addr->basic_errno > 0)
1546 respond_printf(f, ": %s", strerror(addr->basic_errno));
1547 if (addr->message != NULL)
1548 respond_printf(f, ": %s", addr->message);
1549 else if (addr->basic_errno <= 0)
1550 respond_printf(f, ": unknown error");
1553 /* Show parents iff doing full info */
1555 if (full_info) while (p != NULL)
1557 respond_printf(f, "%s\n <-- %s", cr, p->address);
1560 respond_printf(f, "%s\n", cr);
1562 cancel_cutthrough_connection();
1564 if (!full_info) return copy_error(vaddr, addr, DEFER);
1565 else if (yield == OK) yield = DEFER;
1568 /* If we are handling EXPN, we do not want to continue to route beyond
1569 the top level (whose address is in "address"). */
1573 uschar *ok_prefix = US"250-";
1574 if (addr_new == NULL)
1576 if (addr_local == NULL && addr_remote == NULL)
1577 respond_printf(f, "250 mail to <%s> is discarded\r\n", address);
1579 respond_printf(f, "250 <%s>\r\n", address);
1581 else while (addr_new != NULL)
1583 address_item *addr2 = addr_new;
1584 addr_new = addr2->next;
1585 if (addr_new == NULL) ok_prefix = US"250 ";
1586 respond_printf(f, "%s<%s>\r\n", ok_prefix, addr2->address);
1591 /* Successful routing other than EXPN. */
1595 /* Handle successful routing when short info wanted. Otherwise continue for
1596 other (generated) addresses. Short info is the operational case. Full info
1597 can be requested only when debug_selector != 0 and a file is supplied.
1599 There is a conflict between the use of aliasing as an alternate email
1600 address, and as a sort of mailing list. If an alias turns the incoming
1601 address into just one address (e.g. J.Caesar->jc44) you may well want to
1602 carry on verifying the generated address to ensure it is valid when
1603 checking incoming mail. If aliasing generates multiple addresses, you
1604 probably don't want to do this. Exim therefore treats the generation of
1605 just a single new address as a special case, and continues on to verify the
1606 generated address. */
1608 if (!full_info && /* Stop if short info wanted AND */
1609 (((addr_new == NULL || /* No new address OR */
1610 addr_new->next != NULL || /* More than one new address OR */
1611 testflag(addr_new, af_pfr))) /* New address is pfr */
1613 (addr_new != NULL && /* At least one new address AND */
1614 success_on_redirect))) /* success_on_redirect is set */
1616 if (f != NULL) fprintf(f, "%s %s\n", address,
1617 address_test_mode? "is deliverable" : "verified");
1619 /* If we have carried on to verify a child address, we want the value
1620 of $address_data to be that of the child */
1622 vaddr->p.address_data = addr->p.address_data;
1626 } /* Loop for generated addresses */
1628 /* Display the full results of the successful routing, including any generated
1629 addresses. Control gets here only when full_info is set, which requires f not
1630 to be NULL, and this occurs only when a top-level verify is called with the
1631 debugging switch on.
1633 If there are no local and no remote addresses, and there were no pipes, files,
1634 or autoreplies, and there were no errors or deferments, the message is to be
1635 discarded, usually because of the use of :blackhole: in an alias file. */
1637 if (allok && addr_local == NULL && addr_remote == NULL)
1639 fprintf(f, "mail to %s is discarded\n", address);
1643 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
1645 while (addr_list != NULL)
1647 address_item *addr = addr_list;
1648 address_item *p = addr->parent;
1649 addr_list = addr->next;
1651 fprintf(f, "%s", CS addr->address);
1652 #ifdef EXPERIMENTAL_SRS
1653 if(addr->p.srs_sender)
1654 fprintf(f, " [srs = %s]", addr->p.srs_sender);
1657 /* If the address is a duplicate, show something about it. */
1659 if (!testflag(addr, af_pfr))
1662 if ((tnode = tree_search(tree_duplicates, addr->unique)) != NULL)
1663 fprintf(f, " [duplicate, would not be delivered]");
1664 else tree_add_duplicate(addr->unique, addr);
1667 /* Now show its parents */
1671 fprintf(f, "\n <-- %s", p->address);
1676 /* Show router, and transport */
1678 fprintf(f, "router = %s, ", addr->router->name);
1679 fprintf(f, "transport = %s\n", (addr->transport == NULL)? US"unset" :
1680 addr->transport->name);
1682 /* Show any hosts that are set up by a router unless the transport
1683 is going to override them; fiddle a bit to get a nice format. */
1685 if (addr->host_list != NULL && addr->transport != NULL &&
1686 !addr->transport->overrides_hosts)
1691 for (h = addr->host_list; h != NULL; h = h->next)
1693 int len = Ustrlen(h->name);
1694 if (len > maxlen) maxlen = len;
1695 len = (h->address != NULL)? Ustrlen(h->address) : 7;
1696 if (len > maxaddlen) maxaddlen = len;
1698 for (h = addr->host_list; h != NULL; h = h->next)
1700 int len = Ustrlen(h->name);
1701 fprintf(f, " host %s ", h->name);
1702 while (len++ < maxlen) fprintf(f, " ");
1703 if (h->address != NULL)
1705 fprintf(f, "[%s] ", h->address);
1706 len = Ustrlen(h->address);
1708 else if (!addr->transport->info->local) /* Omit [unknown] for local */
1710 fprintf(f, "[unknown] ");
1714 while (len++ < maxaddlen) fprintf(f," ");
1715 if (h->mx >= 0) fprintf(f, "MX=%d", h->mx);
1716 if (h->port != PORT_NONE) fprintf(f, " port=%d", h->port);
1717 if (h->status == hstatus_unusable) fprintf(f, " ** unusable **");
1724 /* Will be DEFER or FAIL if any one address has, only for full_info (which is
1725 the -bv or -bt case). */
1733 /*************************************************
1734 * Check headers for syntax errors *
1735 *************************************************/
1737 /* This function checks those header lines that contain addresses, and verifies
1738 that all the addresses therein are syntactially correct.
1741 msgptr where to put an error message
1748 verify_check_headers(uschar **msgptr)
1754 for (h = header_list; h != NULL && yield == OK; h = h->next)
1756 if (h->type != htype_from &&
1757 h->type != htype_reply_to &&
1758 h->type != htype_sender &&
1759 h->type != htype_to &&
1760 h->type != htype_cc &&
1761 h->type != htype_bcc)
1764 colon = Ustrchr(h->text, ':');
1766 while (isspace(*s)) s++;
1768 /* Loop for multiple addresses in the header, enabling group syntax. Note
1769 that we have to reset this after the header has been scanned. */
1771 parse_allow_group = TRUE;
1775 uschar *ss = parse_find_address_end(s, FALSE);
1776 uschar *recipient, *errmess;
1777 int terminator = *ss;
1778 int start, end, domain;
1780 /* Temporarily terminate the string at this point, and extract the
1781 operative address within, allowing group syntax. */
1784 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1787 /* Permit an unqualified address only if the message is local, or if the
1788 sending host is configured to be permitted to send them. */
1790 if (recipient != NULL && domain == 0)
1792 if (h->type == htype_from || h->type == htype_sender)
1794 if (!allow_unqualified_sender) recipient = NULL;
1798 if (!allow_unqualified_recipient) recipient = NULL;
1800 if (recipient == NULL) errmess = US"unqualified address not permitted";
1803 /* It's an error if no address could be extracted, except for the special
1804 case of an empty address. */
1806 if (recipient == NULL && Ustrcmp(errmess, "empty address") != 0)
1808 uschar *verb = US"is";
1813 /* Arrange not to include any white space at the end in the
1814 error message or the header name. */
1816 while (t > s && isspace(t[-1])) t--;
1817 while (tt > h->text && isspace(tt[-1])) tt--;
1819 /* Add the address that failed to the error message, since in a
1820 header with very many addresses it is sometimes hard to spot
1821 which one is at fault. However, limit the amount of address to
1822 quote - cases have been seen where, for example, a missing double
1823 quote in a humungous To: header creates an "address" that is longer
1824 than string_sprintf can handle. */
1833 *msgptr = string_printing(
1834 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
1835 errmess, tt - h->text, h->text, verb, len, s));
1838 break; /* Out of address loop */
1841 /* Advance to the next address */
1843 s = ss + (terminator? 1:0);
1844 while (isspace(*s)) s++;
1845 } /* Next address */
1847 parse_allow_group = FALSE;
1848 parse_found_group = FALSE;
1849 } /* Next header unless yield has been set FALSE */
1856 /*************************************************
1857 * Check for blind recipients *
1858 *************************************************/
1860 /* This function checks that every (envelope) recipient is mentioned in either
1861 the To: or Cc: header lines, thus detecting blind carbon copies.
1863 There are two ways of scanning that could be used: either scan the header lines
1864 and tick off the recipients, or scan the recipients and check the header lines.
1865 The original proposed patch did the former, but I have chosen to do the latter,
1866 because (a) it requires no memory and (b) will use fewer resources when there
1867 are many addresses in To: and/or Cc: and only one or two envelope recipients.
1870 Returns: OK if there are no blind recipients
1871 FAIL if there is at least one blind recipient
1875 verify_check_notblind(void)
1878 for (i = 0; i < recipients_count; i++)
1882 uschar *address = recipients_list[i].address;
1884 for (h = header_list; !found && h != NULL; h = h->next)
1888 if (h->type != htype_to && h->type != htype_cc) continue;
1890 colon = Ustrchr(h->text, ':');
1892 while (isspace(*s)) s++;
1894 /* Loop for multiple addresses in the header, enabling group syntax. Note
1895 that we have to reset this after the header has been scanned. */
1897 parse_allow_group = TRUE;
1901 uschar *ss = parse_find_address_end(s, FALSE);
1902 uschar *recipient,*errmess;
1903 int terminator = *ss;
1904 int start, end, domain;
1906 /* Temporarily terminate the string at this point, and extract the
1907 operative address within, allowing group syntax. */
1910 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
1913 /* If we found a valid recipient that has a domain, compare it with the
1914 envelope recipient. Local parts are compared case-sensitively, domains
1915 case-insensitively. By comparing from the start with length "domain", we
1916 include the "@" at the end, which ensures that we are comparing the whole
1917 local part of each address. */
1919 if (recipient != NULL && domain != 0)
1921 found = Ustrncmp(recipient, address, domain) == 0 &&
1922 strcmpic(recipient + domain, address + domain) == 0;
1926 /* Advance to the next address */
1928 s = ss + (terminator? 1:0);
1929 while (isspace(*s)) s++;
1930 } /* Next address */
1932 parse_allow_group = FALSE;
1933 parse_found_group = FALSE;
1934 } /* Next header (if found is false) */
1936 if (!found) return FAIL;
1937 } /* Next recipient */
1944 /*************************************************
1945 * Find if verified sender *
1946 *************************************************/
1948 /* Usually, just a single address is verified as the sender of the message.
1949 However, Exim can be made to verify other addresses as well (often related in
1950 some way), and this is useful in some environments. There may therefore be a
1951 chain of such addresses that have previously been tested. This function finds
1952 whether a given address is on the chain.
1954 Arguments: the address to be verified
1955 Returns: pointer to an address item, or NULL
1959 verify_checked_sender(uschar *sender)
1962 for (addr = sender_verified_list; addr != NULL; addr = addr->next)
1963 if (Ustrcmp(sender, addr->address) == 0) break;
1971 /*************************************************
1972 * Get valid header address *
1973 *************************************************/
1975 /* Scan the originator headers of the message, looking for an address that
1976 verifies successfully. RFC 822 says:
1978 o The "Sender" field mailbox should be sent notices of
1979 any problems in transport or delivery of the original
1980 messages. If there is no "Sender" field, then the
1981 "From" field mailbox should be used.
1983 o If the "Reply-To" field exists, then the reply should
1984 go to the addresses indicated in that field and not to
1985 the address(es) indicated in the "From" field.
1987 So we check a Sender field if there is one, else a Reply_to field, else a From
1988 field. As some strange messages may have more than one of these fields,
1989 especially if they are resent- fields, check all of them if there is more than
1993 user_msgptr points to where to put a user error message
1994 log_msgptr points to where to put a log error message
1995 callout timeout for callout check (passed to verify_address())
1996 callout_overall overall callout timeout (ditto)
1997 callout_connect connect callout timeout (ditto)
1998 se_mailfrom mailfrom for verify; NULL => ""
1999 pm_mailfrom sender for pm callout check (passed to verify_address())
2000 options callout options (passed to verify_address())
2001 verrno where to put the address basic_errno
2003 If log_msgptr is set to something without setting user_msgptr, the caller
2004 normally uses log_msgptr for both things.
2006 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2007 FAIL is given if no appropriate headers are found
2011 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2012 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2013 uschar *pm_mailfrom, int options, int *verrno)
2015 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2020 for (i = 0; i < 3 && !done; i++)
2023 for (h = header_list; h != NULL && !done; h = h->next)
2025 int terminator, new_ok;
2026 uschar *s, *ss, *endname;
2028 if (h->type != header_types[i]) continue;
2029 s = endname = Ustrchr(h->text, ':') + 1;
2031 /* Scan the addresses in the header, enabling group syntax. Note that we
2032 have to reset this after the header has been scanned. */
2034 parse_allow_group = TRUE;
2038 address_item *vaddr;
2040 while (isspace(*s) || *s == ',') s++;
2041 if (*s == 0) break; /* End of header */
2043 ss = parse_find_address_end(s, FALSE);
2045 /* The terminator is a comma or end of header, but there may be white
2046 space preceding it (including newline for the last address). Move back
2047 past any white space so we can check against any cached envelope sender
2048 address verifications. */
2050 while (isspace(ss[-1])) ss--;
2054 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2055 (int)(endname - h->text), h->text, s);
2057 /* See if we have already verified this address as an envelope sender,
2058 and if so, use the previous answer. */
2060 vaddr = verify_checked_sender(s);
2062 if (vaddr != NULL && /* Previously checked */
2063 (callout <= 0 || /* No callout needed; OR */
2064 vaddr->special_action > 256)) /* Callout was done */
2066 new_ok = vaddr->special_action & 255;
2067 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2068 *ss = terminator; /* Restore shortened string */
2071 /* Otherwise we run the verification now. We must restore the shortened
2072 string before running the verification, so the headers are correct, in
2073 case there is any rewriting. */
2077 int start, end, domain;
2078 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2083 /* If we found an empty address, just carry on with the next one, but
2084 kill the message. */
2086 if (address == NULL && Ustrcmp(*log_msgptr, "empty address") == 0)
2093 /* If verification failed because of a syntax error, fail this
2094 function, and ensure that the failing address gets added to the error
2097 if (address == NULL)
2100 while (ss > s && isspace(ss[-1])) ss--;
2101 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2102 "scanning for sender: %s in \"%.*s\"",
2103 endname - h->text, h->text, *log_msgptr, ss - s, s);
2109 /* Else go ahead with the sender verification. But it isn't *the*
2110 sender of the message, so set vopt_fake_sender to stop sender_address
2111 being replaced after rewriting or qualification. */
2115 vaddr = deliver_make_addr(address, FALSE);
2116 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2117 callout, callout_overall, callout_connect, se_mailfrom,
2122 /* We now have the result, either newly found, or cached. If we are
2123 giving out error details, set a specific user error. This means that the
2124 last of these will be returned to the user if all three fail. We do not
2125 set a log message - the generic one below will be used. */
2129 *verrno = vaddr->basic_errno;
2130 if (smtp_return_error_details)
2132 *user_msgptr = string_sprintf("Rejected after DATA: "
2133 "could not verify \"%.*s\" header address\n%s: %s",
2134 endname - h->text, h->text, vaddr->address, vaddr->message);
2138 /* Success or defer */
2147 if (new_ok == DEFER) yield = DEFER;
2149 /* Move on to any more addresses in the header */
2152 } /* Next address */
2154 parse_allow_group = FALSE;
2155 parse_found_group = FALSE;
2156 } /* Next header, unless done */
2157 } /* Next header type unless done */
2159 if (yield == FAIL && *log_msgptr == NULL)
2160 *log_msgptr = US"there is no valid sender in any header line";
2162 if (yield == DEFER && *log_msgptr == NULL)
2163 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2171 /*************************************************
2172 * Get RFC 1413 identification *
2173 *************************************************/
2175 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2176 the timeout is set to zero, then the query is not done. There may also be lists
2177 of hosts and nets which are exempt. To guard against malefactors sending
2178 non-printing characters which could, for example, disrupt a message's headers,
2179 make sure the string consists of printing characters only.
2182 port the port to connect to; usually this is IDENT_PORT (113), but when
2183 running in the test harness with -bh a different value is used.
2187 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2191 verify_get_ident(int port)
2193 int sock, host_af, qlen;
2194 int received_sender_port, received_interface_port, n;
2196 uschar buffer[2048];
2198 /* Default is no ident. Check whether we want to do an ident check for this
2201 sender_ident = NULL;
2202 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2205 DEBUG(D_ident) debug_printf("doing ident callback\n");
2207 /* Set up a connection to the ident port of the remote host. Bind the local end
2208 to the incoming interface address. If the sender host address is an IPv6
2209 address, the incoming interface address will also be IPv6. */
2211 host_af = (Ustrchr(sender_host_address, ':') == NULL)? AF_INET : AF_INET6;
2212 sock = ip_socket(SOCK_STREAM, host_af);
2213 if (sock < 0) return;
2215 if (ip_bind(sock, host_af, interface_address, 0) < 0)
2217 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2222 if (ip_connect(sock, host_af, sender_host_address, port, rfc1413_query_timeout)
2225 if (errno == ETIMEDOUT && (log_extra_selector & LX_ident_timeout) != 0)
2227 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2228 sender_host_address);
2232 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2233 sender_host_address, strerror(errno));
2238 /* Construct and send the query. */
2240 sprintf(CS buffer, "%d , %d\r\n", sender_host_port, interface_port);
2241 qlen = Ustrlen(buffer);
2242 if (send(sock, buffer, qlen, 0) < 0)
2244 DEBUG(D_ident) debug_printf("ident send failed: %s\n", strerror(errno));
2248 /* Read a response line. We put it into the rest of the buffer, using several
2249 recv() calls if necessary. */
2257 int size = sizeof(buffer) - (p - buffer);
2259 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2260 count = ip_recv(sock, p, size, rfc1413_query_timeout);
2261 if (count <= 0) goto END_OFF; /* Read error or EOF */
2263 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2264 generous, and accept a plain \n terminator as well. The only illegal
2267 for (pp = p; pp < p + count; pp++)
2269 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2272 if (pp[-1] == '\r') pp--;
2274 goto GOT_DATA; /* Break out of both loops */
2278 /* Reached the end of the data without finding \n. Let the loop continue to
2279 read some more, if there is room. */
2286 /* We have received a line of data. Check it carefully. It must start with the
2287 same two port numbers that we sent, followed by data as defined by the RFC. For
2290 12345 , 25 : USERID : UNIX :root
2292 However, the amount of white space may be different to what we sent. In the
2293 "osname" field there may be several sub-fields, comma separated. The data we
2294 actually want to save follows the third colon. Some systems put leading spaces
2295 in it - we discard those. */
2297 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2298 &received_interface_port, &n) != 2 ||
2299 received_sender_port != sender_host_port ||
2300 received_interface_port != interface_port)
2303 p = buffer + qlen + n;
2304 while(isspace(*p)) p++;
2305 if (*p++ != ':') goto END_OFF;
2306 while(isspace(*p)) p++;
2307 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2309 while(isspace(*p)) p++;
2310 if (*p++ != ':') goto END_OFF;
2311 while (*p != 0 && *p != ':') p++;
2312 if (*p++ == 0) goto END_OFF;
2313 while(isspace(*p)) p++;
2314 if (*p == 0) goto END_OFF;
2316 /* The rest of the line is the data we want. We turn it into printing
2317 characters when we save it, so that it cannot mess up the format of any logging
2318 or Received: lines into which it gets inserted. We keep a maximum of 127
2321 sender_ident = string_printing(string_copyn(p, 127));
2322 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2332 /*************************************************
2333 * Match host to a single host-list item *
2334 *************************************************/
2336 /* This function compares a host (name or address) against a single item
2337 from a host list. The host name gets looked up if it is needed and is not
2338 already known. The function is called from verify_check_this_host() via
2339 match_check_list(), which is why most of its arguments are in a single block.
2342 arg the argument block (see below)
2343 ss the host-list item
2344 valueptr where to pass back looked up data, or NULL
2345 error for error message when returning ERROR
2348 host_name (a) the host name, or
2349 (b) NULL, implying use sender_host_name and
2350 sender_host_aliases, looking them up if required, or
2351 (c) the empty string, meaning that only IP address matches
2353 host_address the host address
2354 host_ipv4 the IPv4 address taken from an IPv6 one
2358 DEFER lookup deferred
2359 ERROR (a) failed to find the host name or IP address, or
2360 (b) unknown lookup type specified, or
2361 (c) host name encountered when only IP addresses are
2366 check_host(void *arg, uschar *ss, uschar **valueptr, uschar **error)
2368 check_host_block *cb = (check_host_block *)arg;
2371 BOOL iplookup = FALSE;
2372 BOOL isquery = FALSE;
2373 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2378 /* Optimize for the special case when the pattern is "*". */
2380 if (*ss == '*' && ss[1] == 0) return OK;
2382 /* If the pattern is empty, it matches only in the case when there is no host -
2383 this can occur in ACL checking for SMTP input using the -bs option. In this
2384 situation, the host address is the empty string. */
2386 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2387 if (*ss == 0) return FAIL;
2389 /* If the pattern is precisely "@" then match against the primary host name,
2390 provided that host name matching is permitted; if it's "@[]" match against the
2391 local host's IP addresses. */
2397 if (isiponly) return ERROR;
2398 ss = primary_hostname;
2400 else if (Ustrcmp(ss, "@[]") == 0)
2402 ip_address_item *ip;
2403 for (ip = host_find_interfaces(); ip != NULL; ip = ip->next)
2404 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2409 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2410 a (possibly masked) comparision with the current IP address. */
2412 if (string_is_ip_address(ss, &maskoffset) != 0)
2413 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2415 /* The pattern is not an IP address. A common error that people make is to omit
2416 one component of an IPv4 address, either by accident, or believing that, for
2417 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,
2418 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2419 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2420 ancient specification.) To aid in debugging these cases, we give a specific
2421 error if the pattern contains only digits and dots or contains a slash preceded
2422 only by digits and dots (a slash at the start indicates a file name and of
2423 course slashes may be present in lookups, but not preceded only by digits and
2426 for (t = ss; isdigit(*t) || *t == '.'; t++);
2427 if (*t == 0 || (*t == '/' && t != ss))
2429 *error = US"malformed IPv4 address or address mask";
2433 /* See if there is a semicolon in the pattern */
2435 semicolon = Ustrchr(ss, ';');
2437 /* If we are doing an IP address only match, then all lookups must be IP
2438 address lookups, even if there is no "net-". */
2442 iplookup = semicolon != NULL;
2445 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2446 a lookup on a masked IP network, in textual form. We obey this code even if we
2447 have already set iplookup, so as to skip over the "net-" prefix and to set the
2448 mask length. The net- stuff really only applies to single-key lookups where the
2449 key is implicit. For query-style lookups the key is specified in the query.
2450 From release 4.30, the use of net- for query style is no longer needed, but we
2451 retain it for backward compatibility. */
2453 if (Ustrncmp(ss, "net", 3) == 0 && semicolon != NULL)
2456 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2457 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2458 iplookup = (*t++ == '-');
2462 /* Do the IP address lookup if that is indeed what we have */
2470 uschar *filename, *key, *result;
2473 /* Find the search type */
2475 search_type = search_findtype(t, semicolon - t);
2477 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2478 search_error_message);
2480 /* Adjust parameters for the type of lookup. For a query-style lookup, there
2481 is no file name, and the "key" is just the query. For query-style with a file
2482 name, we have to fish the file off the start of the query. For a single-key
2483 lookup, the key is the current IP address, masked appropriately, and
2484 reconverted to text form, with the mask appended. For IPv6 addresses, specify
2485 dot separators instead of colons, except when the lookup type is "iplsearch".
2488 if (mac_islookup(search_type, lookup_absfilequery))
2490 filename = semicolon + 1;
2492 while (*key != 0 && !isspace(*key)) key++;
2493 filename = string_copyn(filename, key - filename);
2494 while (isspace(*key)) key++;
2496 else if (mac_islookup(search_type, lookup_querystyle))
2499 key = semicolon + 1;
2501 else /* Single-key style */
2503 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
2505 insize = host_aton(cb->host_address, incoming);
2506 host_mask(insize, incoming, mlen);
2507 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
2509 filename = semicolon + 1;
2512 /* Now do the actual lookup; note that there is no search_close() because
2513 of the caching arrangements. */
2515 handle = search_open(filename, search_type, 0, NULL, NULL);
2516 if (handle == NULL) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
2517 search_error_message);
2518 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL);
2519 if (valueptr != NULL) *valueptr = result;
2520 return (result != NULL)? OK : search_find_defer? DEFER: FAIL;
2523 /* The pattern is not an IP address or network reference of any kind. That is,
2524 it is a host name pattern. If this is an IP only match, there's an error in the
2529 *error = US"cannot match host name in match_ip list";
2533 /* Check the characters of the pattern to see if they comprise only letters,
2534 digits, full stops, and hyphens (the constituents of domain names). Allow
2535 underscores, as they are all too commonly found. Sigh. Also, if
2536 allow_utf8_domains is set, allow top-bit characters. */
2538 for (t = ss; *t != 0; t++)
2539 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
2540 (!allow_utf8_domains || *t < 128)) break;
2542 /* If the pattern is a complete domain name, with no fancy characters, look up
2543 its IP address and match against that. Note that a multi-homed host will add
2544 items to the chain. */
2555 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
2556 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
2559 for (hh = &h; hh != NULL; hh = hh->next)
2561 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
2565 if (rc == HOST_FIND_AGAIN) return DEFER;
2566 *error = string_sprintf("failed to find IP address for %s", ss);
2570 /* Almost all subsequent comparisons require the host name, and can be done
2571 using the general string matching function. When this function is called for
2572 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
2573 must use sender_host_name and its aliases, looking them up if necessary. */
2575 if (cb->host_name != NULL) /* Explicit host name given */
2576 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
2579 /* Host name not given; in principle we need the sender host name and its
2580 aliases. However, for query-style lookups, we do not need the name if the
2581 query does not contain $sender_host_name. From release 4.23, a reference to
2582 $sender_host_name causes it to be looked up, so we don't need to do the lookup
2585 if ((semicolon = Ustrchr(ss, ';')) != NULL)
2588 int partial, affixlen, starflags, id;
2591 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags);
2594 if (id < 0) /* Unknown lookup type */
2596 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
2597 search_error_message, ss);
2600 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
2605 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
2608 case DEFER: return DEFER;
2609 default: return FAIL;
2613 /* Not a query-style lookup; must ensure the host name is present, and then we
2614 do a check on the name and all its aliases. */
2616 if (sender_host_name == NULL)
2618 HDEBUG(D_host_lookup)
2619 debug_printf("sender host name required, to match against %s\n", ss);
2620 if (host_lookup_failed || host_name_lookup() != OK)
2622 *error = string_sprintf("failed to find host name for %s",
2623 sender_host_address);;
2626 host_build_sender_fullhost();
2629 /* Match on the sender host name, using the general matching function */
2631 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE,
2635 case DEFER: return DEFER;
2638 /* If there are aliases, try matching on them. */
2640 aliases = sender_host_aliases;
2641 while (*aliases != NULL)
2643 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
2646 case DEFER: return DEFER;
2655 /*************************************************
2656 * Check a specific host matches a host list *
2657 *************************************************/
2659 /* This function is passed a host list containing items in a number of
2660 different formats and the identity of a host. Its job is to determine whether
2661 the given host is in the set of hosts defined by the list. The host name is
2662 passed as a pointer so that it can be looked up if needed and not already
2663 known. This is commonly the case when called from verify_check_host() to check
2664 an incoming connection. When called from elsewhere the host name should usually
2667 This function is now just a front end to match_check_list(), which runs common
2668 code for scanning a list. We pass it the check_host() function to perform a
2672 listptr pointer to the host list
2673 cache_bits pointer to cache for named lists, or NULL
2674 host_name the host name or NULL, implying use sender_host_name and
2675 sender_host_aliases, looking them up if required
2676 host_address the IP address
2677 valueptr if not NULL, data from a lookup is passed back here
2679 Returns: OK if the host is in the defined set
2680 FAIL if the host is not in the defined set,
2681 DEFER if a data lookup deferred (not a host lookup)
2683 If the host name was needed in order to make a comparison, and could not be
2684 determined from the IP address, the result is FAIL unless the item
2685 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
2688 verify_check_this_host(uschar **listptr, unsigned int *cache_bits,
2689 uschar *host_name, uschar *host_address, uschar **valueptr)
2692 unsigned int *local_cache_bits = cache_bits;
2693 uschar *save_host_address = deliver_host_address;
2694 check_host_block cb;
2695 cb.host_name = host_name;
2696 cb.host_address = host_address;
2698 if (valueptr != NULL) *valueptr = NULL;
2700 /* If the host address starts off ::ffff: it is an IPv6 address in
2701 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
2704 cb.host_ipv4 = (Ustrncmp(host_address, "::ffff:", 7) == 0)?
2705 host_address + 7 : host_address;
2707 /* During the running of the check, put the IP address into $host_address. In
2708 the case of calls from the smtp transport, it will already be there. However,
2709 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
2710 the safe side, any existing setting is preserved, though as I write this
2711 (November 2004) I can't see any cases where it is actually needed. */
2713 deliver_host_address = host_address;
2714 rc = match_check_list(
2715 listptr, /* the list */
2716 0, /* separator character */
2717 &hostlist_anchor, /* anchor pointer */
2718 &local_cache_bits, /* cache pointer */
2719 check_host, /* function for testing */
2720 &cb, /* argument for function */
2721 MCL_HOST, /* type of check */
2722 (host_address == sender_host_address)?
2723 US"host" : host_address, /* text for debugging */
2724 valueptr); /* where to pass back data */
2725 deliver_host_address = save_host_address;
2732 /*************************************************
2733 * Check the remote host matches a list *
2734 *************************************************/
2736 /* This is a front end to verify_check_this_host(), created because checking
2737 the remote host is a common occurrence. With luck, a good compiler will spot
2738 the tail recursion and optimize it. If there's no host address, this is
2739 command-line SMTP input - check against an empty string for the address.
2742 listptr pointer to the host list
2744 Returns: the yield of verify_check_this_host(),
2745 i.e. OK, FAIL, or DEFER
2749 verify_check_host(uschar **listptr)
2751 return verify_check_this_host(listptr, sender_host_cache, NULL,
2752 (sender_host_address == NULL)? US"" : sender_host_address, NULL);
2759 /*************************************************
2760 * Invert an IP address *
2761 *************************************************/
2763 /* Originally just used for DNS xBL lists, now also used for the
2764 reverse_ip expansion operator.
2767 buffer where to put the answer
2768 address the address to invert
2772 invert_address(uschar *buffer, uschar *address)
2775 uschar *bptr = buffer;
2777 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
2778 to the IPv4 part only. */
2780 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
2782 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
2785 if (host_aton(address, bin) == 1)
2789 for (i = 0; i < 4; i++)
2791 sprintf(CS bptr, "%d.", x & 255);
2792 while (*bptr) bptr++;
2797 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
2798 in any DNS black lists, and the format in which they will be looked up is
2799 unknown. This is just a guess. */
2805 for (j = 3; j >= 0; j--)
2808 for (i = 0; i < 8; i++)
2810 sprintf(CS bptr, "%x.", x & 15);
2811 while (*bptr) bptr++;
2818 /* Remove trailing period -- this is needed so that both arbitrary
2819 dnsbl keydomains and inverted addresses may be combined with the
2820 same format string, "%s.%s" */
2827 /*************************************************
2828 * Perform a single dnsbl lookup *
2829 *************************************************/
2831 /* This function is called from verify_check_dnsbl() below. It is also called
2832 recursively from within itself when domain and domain_txt are different
2833 pointers, in order to get the TXT record from the alternate domain.
2836 domain the outer dnsbl domain
2837 domain_txt alternate domain to lookup TXT record on success; when the
2838 same domain is to be used, domain_txt == domain (that is,
2839 the pointers must be identical, not just the text)
2840 keydomain the current keydomain (for debug message)
2841 prepend subdomain to lookup (like keydomain, but
2842 reversed if IP address)
2843 iplist the list of matching IP addresses, or NULL for "any"
2844 bitmask true if bitmask matching is wanted
2845 match_type condition for 'succeed' result
2846 0 => Any RR in iplist (=)
2847 1 => No RR in iplist (!=)
2848 2 => All RRs in iplist (==)
2849 3 => Some RRs not in iplist (!==)
2850 the two bits are defined as MT_NOT and MT_ALL
2851 defer_return what to return for a defer
2853 Returns: OK if lookup succeeded
2858 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
2859 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
2865 dnsbl_cache_block *cb;
2866 int old_pool = store_pool;
2867 uschar query[256]; /* DNS domain max length */
2869 /* Construct the specific query domainname */
2871 if (!string_format(query, sizeof(query), "%s.%s", prepend, domain))
2873 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
2874 "(ignored): %s...", query);
2878 /* Look for this query in the cache. */
2880 t = tree_search(dnsbl_cache, query);
2882 /* If not cached from a previous lookup, we must do a DNS lookup, and
2883 cache the result in permanent memory. */
2887 store_pool = POOL_PERM;
2889 /* Set up a tree entry to cache the lookup */
2891 t = store_get(sizeof(tree_node) + Ustrlen(query));
2892 Ustrcpy(t->name, query);
2893 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block));
2894 (void)tree_insertnode(&dnsbl_cache, t);
2896 /* Do the DNS loopup . */
2898 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
2899 cb->rc = dns_basic_lookup(&dnsa, query, T_A);
2900 cb->text_set = FALSE;
2904 /* If the lookup succeeded, cache the RHS address. The code allows for
2905 more than one address - this was for complete generality and the possible
2906 use of A6 records. However, A6 records have been reduced to experimental
2907 status (August 2001) and may die out. So they may never get used at all,
2908 let alone in dnsbl records. However, leave the code here, just in case.
2910 Quite apart from one A6 RR generating multiple addresses, there are DNS
2911 lists that return more than one A record, so we must handle multiple
2912 addresses generated in that way as well. */
2914 if (cb->rc == DNS_SUCCEED)
2917 dns_address **addrp = &(cb->rhs);
2918 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
2920 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
2922 if (rr->type == T_A)
2924 dns_address *da = dns_address_from_rr(&dnsa, rr);
2928 while (da->next != NULL) da = da->next;
2929 addrp = &(da->next);
2934 /* If we didn't find any A records, change the return code. This can
2935 happen when there is a CNAME record but there are no A records for what
2938 if (cb->rhs == NULL) cb->rc = DNS_NODATA;
2941 store_pool = old_pool;
2944 /* Previous lookup was cached */
2948 HDEBUG(D_dnsbl) debug_printf("using result of previous DNS lookup\n");
2952 /* We now have the result of the DNS lookup, either newly done, or cached
2953 from a previous call. If the lookup succeeded, check against the address
2954 list if there is one. This may be a positive equality list (introduced by
2955 "="), a negative equality list (introduced by "!="), a positive bitmask
2956 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
2958 if (cb->rc == DNS_SUCCEED)
2960 dns_address *da = NULL;
2961 uschar *addlist = cb->rhs->address;
2963 /* For A and AAAA records, there may be multiple addresses from multiple
2964 records. For A6 records (currently not expected to be used) there may be
2965 multiple addresses from a single record. */
2967 for (da = cb->rhs->next; da != NULL; da = da->next)
2968 addlist = string_sprintf("%s, %s", addlist, da->address);
2970 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
2973 /* Address list check; this can be either for equality, or via a bitmask.
2974 In the latter case, all the bits must match. */
2978 for (da = cb->rhs; da != NULL; da = da->next)
2982 uschar *ptr = iplist;
2985 /* Handle exact matching */
2989 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
2991 if (Ustrcmp(CS da->address, ip) == 0) break;
2995 /* Handle bitmask matching */
3002 /* At present, all known DNS blocking lists use A records, with
3003 IPv4 addresses on the RHS encoding the information they return. I
3004 wonder if this will linger on as the last vestige of IPv4 when IPv6
3005 is ubiquitous? Anyway, for now we use paranoia code to completely
3006 ignore IPv6 addresses. The default mask is 0, which always matches.
3007 We change this only for IPv4 addresses in the list. */
3009 if (host_aton(da->address, address) == 1) mask = address[0];
3011 /* Scan the returned addresses, skipping any that are IPv6 */
3013 while ((res = string_nextinlist(&ptr, &ipsep, ip, sizeof(ip))) != NULL)
3015 if (host_aton(ip, address) != 1) continue;
3016 if ((address[0] & mask) == address[0]) break;
3022 (a) An IP address in an any ('=') list matched, or
3023 (b) No IP address in an all ('==') list matched
3025 then we're done searching. */
3027 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3030 /* If da == NULL, either
3032 (a) No IP address in an any ('=') list matched, or
3033 (b) An IP address in an all ('==') list didn't match
3035 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3038 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3046 res = US"was no match";
3049 res = US"was an exclude match";
3052 res = US"was an IP address that did not match";
3055 res = US"were no IP addresses that did not match";
3058 debug_printf("=> but we are not accepting this block class because\n");
3059 debug_printf("=> there %s for %s%c%s\n",
3061 ((match_type & MT_ALL) == 0)? "" : "=",
3062 bitmask? '&' : '=', iplist);
3068 /* Either there was no IP list, or the record matched, implying that the
3069 domain is on the list. We now want to find a corresponding TXT record. If an
3070 alternate domain is specified for the TXT record, call this function
3071 recursively to look that up; this has the side effect of re-checking that
3072 there is indeed an A record at the alternate domain. */
3074 if (domain_txt != domain)
3075 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3076 FALSE, match_type, defer_return);
3078 /* If there is no alternate domain, look up a TXT record in the main domain
3079 if it has not previously been cached. */
3083 cb->text_set = TRUE;
3084 if (dns_basic_lookup(&dnsa, query, T_TXT) == DNS_SUCCEED)
3087 for (rr = dns_next_rr(&dnsa, &dnss, RESET_ANSWERS);
3089 rr = dns_next_rr(&dnsa, &dnss, RESET_NEXT))
3090 if (rr->type == T_TXT) break;
3093 int len = (rr->data)[0];
3094 if (len > 511) len = 127;
3095 store_pool = POOL_PERM;
3096 cb->text = string_sprintf("%.*s", len, (const uschar *)(rr->data+1));
3097 store_pool = old_pool;
3102 dnslist_value = addlist;
3103 dnslist_text = cb->text;
3107 /* There was a problem with the DNS lookup */
3109 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3111 log_write(L_dnslist_defer, LOG_MAIN,
3112 "DNS list lookup defer (probably timeout) for %s: %s", query,
3113 (defer_return == OK)? US"assumed in list" :
3114 (defer_return == FAIL)? US"assumed not in list" :
3115 US"returned DEFER");
3116 return defer_return;
3119 /* No entry was found in the DNS; continue for next domain */
3123 debug_printf("DNS lookup for %s failed\n", query);
3124 debug_printf("=> that means %s is not listed at %s\n",
3134 /*************************************************
3135 * Check host against DNS black lists *
3136 *************************************************/
3138 /* This function runs checks against a list of DNS black lists, until one
3139 matches. Each item on the list can be of the form
3141 domain=ip-address/key
3143 The domain is the right-most domain that is used for the query, for example,
3144 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3145 if the DNS lookup returns a matching IP address. Several addresses may be
3146 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3148 If no key is given, what is looked up in the domain is the inverted IP address
3149 of the current client host. If a key is given, it is used to construct the
3150 domain for the lookup. For example:
3152 dsn.rfc-ignorant.org/$sender_address_domain
3154 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3155 then we check for a TXT record for an error message, and if found, save its
3156 value in $dnslist_text. We also cache everything in a tree, to optimize
3159 The TXT record is normally looked up in the same domain as the A record, but
3160 when many lists are combined in a single DNS domain, this will not be a very
3161 specific message. It is possible to specify a different domain for looking up
3162 TXT records; this is given before the main domain, comma-separated. For
3165 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3166 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3168 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3170 Note: an address for testing RBL is 192.203.178.39
3171 Note: an address for testing DUL is 192.203.178.4
3172 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3175 listptr the domain/address/data list
3177 Returns: OK successful lookup (i.e. the address is on the list), or
3178 lookup deferred after +include_unknown
3179 FAIL name not found, or no data found for the given type, or
3180 lookup deferred after +exclude_unknown (default)
3181 DEFER lookup failure, if +defer_unknown was set
3185 verify_check_dnsbl(uschar **listptr)
3188 int defer_return = FAIL;
3189 uschar *list = *listptr;
3192 uschar buffer[1024];
3193 uschar revadd[128]; /* Long enough for IPv6 address */
3195 /* Indicate that the inverted IP address is not yet set up */
3199 /* In case this is the first time the DNS resolver is being used. */
3201 dns_init(FALSE, FALSE);
3203 /* Loop through all the domains supplied, until something matches */
3205 while ((domain = string_nextinlist(&list, &sep, buffer, sizeof(buffer))) != NULL)
3208 BOOL bitmask = FALSE;
3215 HDEBUG(D_dnsbl) debug_printf("DNS list check: %s\n", domain);
3217 /* Deal with special values that change the behaviour on defer */
3219 if (domain[0] == '+')
3221 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3222 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3223 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3225 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3230 /* See if there's explicit data to be looked up */
3232 key = Ustrchr(domain, '/');
3233 if (key != NULL) *key++ = 0;
3235 /* See if there's a list of addresses supplied after the domain name. This is
3236 introduced by an = or a & character; if preceded by = we require all matches
3237 and if preceded by ! we invert the result. */
3239 iplist = Ustrchr(domain, '=');
3243 iplist = Ustrchr(domain, '&');
3246 if (iplist != NULL) /* Found either = or & */
3248 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3250 match_type |= MT_NOT;
3254 *iplist++ = 0; /* Terminate domain, move on */
3256 /* If we found = (bitmask == FALSE), check for == or =& */
3258 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3260 bitmask = *iplist++ == '&';
3261 match_type |= MT_ALL;
3265 /* If there is a comma in the domain, it indicates that a second domain for
3266 looking up TXT records is provided, before the main domain. Otherwise we must
3267 set domain_txt == domain. */
3269 domain_txt = domain;
3270 comma = Ustrchr(domain, ',');
3277 /* Check that what we have left is a sensible domain name. There is no reason
3278 why these domains should in fact use the same syntax as hosts and email
3279 domains, but in practice they seem to. However, there is little point in
3280 actually causing an error here, because that would no doubt hold up incoming
3281 mail. Instead, I'll just log it. */
3283 for (s = domain; *s != 0; s++)
3285 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3287 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3288 "strange characters - is this right?", domain);
3293 /* Check the alternate domain if present */
3295 if (domain_txt != domain) for (s = domain_txt; *s != 0; s++)
3297 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3299 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3300 "strange characters - is this right?", domain_txt);
3305 /* If there is no key string, construct the query by adding the domain name
3306 onto the inverted host address, and perform a single DNS lookup. */
3310 if (sender_host_address == NULL) return FAIL; /* can never match */
3311 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3312 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3313 iplist, bitmask, match_type, defer_return);
3316 dnslist_domain = string_copy(domain_txt);
3317 dnslist_matched = string_copy(sender_host_address);
3318 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3319 sender_host_address, dnslist_domain);
3321 if (rc != FAIL) return rc; /* OK or DEFER */
3324 /* If there is a key string, it can be a list of domains or IP addresses to
3325 be concatenated with the main domain. */
3332 uschar keybuffer[256];
3333 uschar keyrevadd[128];
3335 while ((keydomain = string_nextinlist(&key, &keysep, keybuffer,
3336 sizeof(keybuffer))) != NULL)
3338 uschar *prepend = keydomain;
3340 if (string_is_ip_address(keydomain, NULL) != 0)
3342 invert_address(keyrevadd, keydomain);
3343 prepend = keyrevadd;
3346 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3347 bitmask, match_type, defer_return);
3351 dnslist_domain = string_copy(domain_txt);
3352 dnslist_matched = string_copy(keydomain);
3353 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3354 keydomain, dnslist_domain);
3358 /* If the lookup deferred, remember this fact. We keep trying the rest
3359 of the list to see if we get a useful result, and if we don't, we return
3360 DEFER at the end. */
3362 if (rc == DEFER) defer = TRUE;
3363 } /* continue with next keystring domain/address */
3365 if (defer) return DEFER;
3367 } /* continue with next dnsdb outer domain */
3372 /* End of verify.c */