1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim Maintainers 2020 */
7 /* See the file NOTICE for conditions of use and distribution. */
9 /* Functions concerned with verifying things. The original code for callout
10 caching was contributed by Kevin Fleming (but I hacked it around a bit). */
14 #include "transports/smtp.h"
16 #define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
17 #define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
18 static smtp_context ctctx;
19 uschar ctbuffer[8192];
22 /* Structure for caching DNSBL lookups */
24 typedef struct dnsbl_cache_block {
33 /* Anchor for DNSBL cache */
35 static tree_node *dnsbl_cache = NULL;
38 /* Bits for match_type in one_check_dnsbl() */
43 static uschar cutthrough_response(client_conn_ctx *, char, uschar **, int);
47 /*************************************************
48 * Retrieve a callout cache record *
49 *************************************************/
51 /* If a record exists, check whether it has expired.
54 dbm_file an open hints file
56 type "address" or "domain"
57 positive_expire expire time for positive records
58 negative_expire expire time for negative records
60 Returns: the cache record if a non-expired one exists, else NULL
63 static dbdata_callout_cache *
64 get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
65 int positive_expire, int negative_expire)
70 dbdata_callout_cache *cache_record;
72 if (!(cache_record = dbfn_read_with_length(dbm_file, key, &length)))
74 HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
78 /* We treat a record as "negative" if its result field is not positive, or if
79 it is a domain record and the postmaster field is negative. */
81 negative = cache_record->result != ccache_accept ||
82 (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
83 expire = negative? negative_expire : positive_expire;
86 if (now - cache_record->time_stamp > expire)
88 HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
92 /* If this is a non-reject domain record, check for the obsolete format version
93 that doesn't have the postmaster and random timestamps, by looking at the
94 length. If so, copy it to a new-style block, replicating the record's
95 timestamp. Then check the additional timestamps. (There's no point wasting
96 effort if connections are rejected.) */
98 if (type[0] == 'd' && cache_record->result != ccache_reject)
100 if (length == sizeof(dbdata_callout_cache_obs))
102 dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache), FALSE);
103 memcpy(new, cache_record, length);
104 new->postmaster_stamp = new->random_stamp = new->time_stamp;
108 if (now - cache_record->postmaster_stamp > expire)
109 cache_record->postmaster_result = ccache_unknown;
111 if (now - cache_record->random_stamp > expire)
112 cache_record->random_result = ccache_unknown;
115 HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
121 /* Check the callout cache.
122 Options * pm_mailfrom may be modified by cache partial results.
124 Return: TRUE if result found
128 cached_callout_lookup(address_item * addr, uschar * address_key,
129 uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
130 int * yield, uschar ** failure_ptr,
131 dbdata_callout_cache * new_domain_record, int * old_domain_res)
133 int options = *opt_ptr;
135 open_db *dbm_file = NULL;
137 /* Open the callout cache database, it it exists, for reading only at this
138 stage, unless caching has been disabled. */
140 if (options & vopt_callout_no_cache)
142 HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
144 else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE, TRUE)))
146 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
150 /* If a cache database is available see if we can avoid the need to do an
151 actual callout by making use of previously-obtained data. */
153 dbdata_callout_cache_address * cache_address_record;
154 dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
155 addr->domain, US"domain",
156 callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
158 /* If an unexpired cache record was found for this domain, see if the callout
159 process can be short-circuited. */
163 /* In most cases, if an early command (up to and including MAIL FROM:<>)
164 was rejected, there is no point carrying on. The callout fails. However, if
165 we are doing a recipient verification with use_sender or use_postmaster
166 set, a previous failure of MAIL FROM:<> doesn't count, because this time we
167 will be using a non-empty sender. We have to remember this situation so as
168 not to disturb the cached domain value if this whole verification succeeds
169 (we don't want it turning into "accept"). */
171 *old_domain_res = cache_record->result;
173 if ( cache_record->result == ccache_reject
174 || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
177 debug_printf("callout cache: domain gave initial rejection, or "
178 "does not accept HELO or MAIL FROM:<>\n");
179 setflag(addr, af_verify_nsfail);
180 addr->user_message = US"(result of an earlier callout reused).";
182 *failure_ptr = US"mail";
183 dbfn_close(dbm_file);
187 /* If a previous check on a "random" local part was accepted, we assume
188 that the server does not do any checking on local parts. There is therefore
189 no point in doing the callout, because it will always be successful. If a
190 random check previously failed, arrange not to do it again, but preserve
191 the data in the new record. If a random check is required but hasn't been
192 done, skip the remaining cache processing. */
194 if (options & vopt_callout_random) switch(cache_record->random_result)
198 debug_printf("callout cache: domain accepts random addresses\n");
199 *failure_ptr = US"random";
200 dbfn_close(dbm_file);
201 return TRUE; /* Default yield is OK */
205 debug_printf("callout cache: domain rejects random addresses\n");
206 *opt_ptr = options & ~vopt_callout_random;
207 new_domain_record->random_result = ccache_reject;
208 new_domain_record->random_stamp = cache_record->random_stamp;
213 debug_printf("callout cache: need to check random address handling "
214 "(not cached or cache expired)\n");
215 dbfn_close(dbm_file);
219 /* If a postmaster check is requested, but there was a previous failure,
220 there is again no point in carrying on. If a postmaster check is required,
221 but has not been done before, we are going to have to do a callout, so skip
222 remaining cache processing. */
226 if (cache_record->postmaster_result == ccache_reject)
228 setflag(addr, af_verify_pmfail);
230 debug_printf("callout cache: domain does not accept "
231 "RCPT TO:<postmaster@domain>\n");
233 *failure_ptr = US"postmaster";
234 setflag(addr, af_verify_pmfail);
235 addr->user_message = US"(result of earlier verification reused).";
236 dbfn_close(dbm_file);
239 if (cache_record->postmaster_result == ccache_unknown)
242 debug_printf("callout cache: need to check RCPT "
243 "TO:<postmaster@domain> (not cached or cache expired)\n");
244 dbfn_close(dbm_file);
248 /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
249 postmaster check if the address itself has to be checked. Also ensure
250 that the value in the cache record is preserved (with its old timestamp).
253 HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
254 "TO:<postmaster@domain>\n");
256 new_domain_record->postmaster_result = ccache_accept;
257 new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
261 /* We can't give a result based on information about the domain. See if there
262 is an unexpired cache record for this specific address (combined with the
263 sender address if we are doing a recipient callout with a non-empty sender).
266 if (!(cache_address_record = (dbdata_callout_cache_address *)
267 get_callout_cache_record(dbm_file, address_key, US"address",
268 callout_cache_positive_expire, callout_cache_negative_expire)))
270 dbfn_close(dbm_file);
274 if (cache_address_record->result == ccache_accept)
277 debug_printf("callout cache: address record is positive\n");
282 debug_printf("callout cache: address record is negative\n");
283 addr->user_message = US"Previous (cached) callout verification failure";
284 *failure_ptr = US"recipient";
288 /* Close the cache database while we actually do the callout for real. */
290 dbfn_close(dbm_file);
297 /* Write results to callout cache
300 cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
301 int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
304 open_db *dbm_file = NULL;
306 /* If we get here with done == TRUE, a successful callout happened, and yield
307 will be set OK or FAIL according to the response to the RCPT command.
308 Otherwise, we looped through the hosts but couldn't complete the business.
309 However, there may be domain-specific information to cache in both cases.
311 The value of the result field in the new_domain record is ccache_unknown if
312 there was an error before or with MAIL FROM:, and errno was not zero,
313 implying some kind of I/O error. We don't want to write the cache in that case.
314 Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
316 if (dom_rec->result != ccache_unknown)
317 if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE)))
319 HDEBUG(D_verify) debug_printf("callout cache: not available\n");
323 (void)dbfn_write(dbm_file, domain, dom_rec,
324 (int)sizeof(dbdata_callout_cache));
325 HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
326 " result=%d postmaster=%d random=%d\n",
329 dom_rec->postmaster_result,
330 dom_rec->random_result);
333 /* If a definite result was obtained for the callout, cache it unless caching
336 if (done && addr_rec->result != ccache_unknown)
339 dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE);
342 HDEBUG(D_verify) debug_printf("no callout cache available\n");
346 (void)dbfn_write(dbm_file, address_key, addr_rec,
347 (int)sizeof(dbdata_callout_cache_address));
348 HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
349 addr_rec->result == ccache_accept ? "positive" : "negative",
354 if (dbm_file) dbfn_close(dbm_file);
358 /* Cutthrough-multi. If the existing cached cutthrough connection matches
359 the one we would make for a subsequent recipient, use it. Send the RCPT TO
360 and check the result, nonpipelined as it may be wanted immediately for
361 recipient-verification.
363 It seems simpler to deal with this case separately from the main callout loop.
364 We will need to remember it has sent, or not, so that rcpt-acl tail code
365 can do it there for the non-rcpt-verify case. For this we keep an addresscount.
367 Return: TRUE for a definitive result for the recipient
370 cutthrough_multi(address_item * addr, host_item * host_list,
371 transport_feedback * tf, int * yield)
375 if (addr->transport == cutthrough.addr.transport)
376 for (host_item * host = host_list; host; host = host->next)
377 if (Ustrcmp(host->address, cutthrough.host.address) == 0)
380 uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
383 deliver_host = host->name;
384 deliver_host_address = host->address;
385 deliver_host_port = host->port;
386 deliver_domain = addr->domain;
387 transport_name = addr->transport->name;
389 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
391 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
393 || !smtp_get_port(tf->port, addr, &port, US"callout")
395 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
398 smtp_port_for_connect(host, port);
400 if ( ( interface == cutthrough.interface
402 && cutthrough.interface
403 && Ustrcmp(interface, cutthrough.interface) == 0
405 && host->port == cutthrough.host.port
408 uschar * resp = NULL;
410 /* Match! Send the RCPT TO, set done from the response */
412 smtp_write_command(&ctctx, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
413 transport_rcpt_address(addr,
414 addr->transport->rcpt_include_affixes)) >= 0
415 && cutthrough_response(&cutthrough.cctx, '2', &resp,
416 CUTTHROUGH_DATA_TIMEOUT) == '2';
418 /* This would go horribly wrong if a callout fail was ignored by ACL.
419 We punt by abandoning cutthrough on a reject, like the
424 address_item * na = store_get(sizeof(address_item), FALSE);
425 *na = cutthrough.addr;
426 cutthrough.addr = *addr;
427 cutthrough.addr.host_used = &cutthrough.host;
428 cutthrough.addr.next = na;
434 cancel_cutthrough_connection(TRUE, US"recipient rejected");
435 if (!resp || errno == ETIMEDOUT)
437 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
442 Ustrcpy(resp, US"connection dropped");
445 string_sprintf("response to \"%s\" was: %s",
446 big_buffer, string_printing(resp));
449 string_sprintf("Callout verification failed:\n%s", resp);
451 /* Hard rejection ends the process */
453 if (resp[0] == '5') /* Address rejected */
461 break; /* host_list */
464 cancel_cutthrough_connection(TRUE, US"incompatible connection");
469 /*************************************************
470 * Do callout verification for an address *
471 *************************************************/
473 /* This function is called from verify_address() when the address has routed to
474 a host list, and a callout has been requested. Callouts are expensive; that is
475 why a cache is used to improve the efficiency.
478 addr the address that's been routed
479 host_list the list of hosts to try
480 tf the transport feedback block
482 ifstring "interface" option from transport, or NULL
483 portstring "port" option from transport, or NULL
484 protocolstring "protocol" option from transport, or NULL
485 callout the per-command callout timeout
486 callout_overall the overall callout timeout (if < 0 use 4*callout)
487 callout_connect the callout connection timeout (if < 0 use callout)
488 options the verification options - these bits are used:
489 vopt_is_recipient => this is a recipient address
490 vopt_callout_no_cache => don't use callout cache
491 vopt_callout_fullpm => if postmaster check, do full one
492 vopt_callout_random => do the "random" thing
493 vopt_callout_recipsender => use real sender for recipient
494 vopt_callout_recippmaster => use postmaster for recipient
495 vopt_callout_hold => lazy close connection
496 se_mailfrom MAIL FROM address for sender verify; NULL => ""
497 pm_mailfrom if non-NULL, do the postmaster check with this sender
499 Returns: OK/FAIL/DEFER
503 do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
504 int callout, int callout_overall, int callout_connect, int options,
505 uschar *se_mailfrom, uschar *pm_mailfrom)
508 int old_domain_cache_result = ccache_accept;
511 uschar *from_address;
512 uschar *random_local_part = NULL;
513 const uschar *save_deliver_domain = deliver_domain;
514 uschar **failure_ptr = options & vopt_is_recipient
515 ? &recipient_verify_failure : &sender_verify_failure;
516 dbdata_callout_cache new_domain_record;
517 dbdata_callout_cache_address new_address_record;
518 time_t callout_start_time;
520 new_domain_record.result = ccache_unknown;
521 new_domain_record.postmaster_result = ccache_unknown;
522 new_domain_record.random_result = ccache_unknown;
524 memset(&new_address_record, 0, sizeof(new_address_record));
526 /* For a recipient callout, the key used for the address cache record must
527 include the sender address if we are using the real sender in the callout,
528 because that may influence the result of the callout. */
530 if (options & vopt_is_recipient)
531 if (options & vopt_callout_recipsender)
533 from_address = sender_address;
534 address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
535 if (cutthrough.delivery) options |= vopt_callout_no_cache;
537 else if (options & vopt_callout_recippmaster)
539 from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
540 address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
541 qualify_domain_sender);
546 address_key = addr->address;
549 /* For a sender callout, we must adjust the key if the mailfrom address is not
554 from_address = se_mailfrom ? se_mailfrom : US"";
555 address_key = *from_address
556 ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
559 if (cached_callout_lookup(addr, address_key, from_address,
560 &options, &pm_mailfrom, &yield, failure_ptr,
561 &new_domain_record, &old_domain_cache_result))
563 cancel_cutthrough_connection(TRUE, US"cache-hit");
567 if (!addr->transport)
569 HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
571 else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
572 log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
573 addr->transport->name, addr->transport->driver_name);
576 smtp_transport_options_block *ob =
577 (smtp_transport_options_block *)addr->transport->options_block;
578 smtp_context * sx = NULL;
580 /* The information wasn't available in the cache, so we have to do a real
581 callout and save the result in the cache for next time, unless no_cache is set,
582 or unless we have a previously cached negative random result. If we are to test
583 with a random local part, ensure that such a local part is available. If not,
584 log the fact, but carry on without randomising. */
586 if (options & vopt_callout_random && callout_random_local_part)
587 if (!(random_local_part = expand_string(callout_random_local_part)))
588 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
589 "callout_random_local_part: %s", expand_string_message);
591 /* Compile regex' used by client-side smtp */
595 /* Default the connect and overall callout timeouts if not set, and record the
596 time we are starting so that we can enforce it. */
598 if (callout_overall < 0) callout_overall = 4 * callout;
599 if (callout_connect < 0) callout_connect = callout;
600 callout_start_time = time(NULL);
602 /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
603 output because a callout might take some time. When PIPELINING is active and
604 there are many recipients, the total time for doing lots of callouts can add up
605 and cause the client to time out. So in this case we forgo the PIPELINING
608 if (smtp_out && !f.disable_callout_flush) mac_smtp_fflush();
610 clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
611 clearflag(addr, af_verify_nsfail); /* null sender callout flag */
613 /* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
614 and we are holding a cutthrough conn open, we can just append the rcpt to
615 that conn for verification purposes (and later delivery also). Simplest
616 coding means skipping this whole loop and doing the append separately. */
618 /* Can we re-use an open cutthrough connection? */
619 if ( cutthrough.cctx.sock >= 0
620 && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
621 == vopt_callout_recipsender
622 && !random_local_part
625 done = cutthrough_multi(addr, host_list, tf, &yield);
627 /* If we did not use a cached connection, make connections to the hosts
628 and do real callouts. The list of hosts is passed in as an argument. */
630 for (host_item * host = host_list; host && !done; host = host->next)
634 uschar * interface = NULL; /* Outgoing interface to use; NULL => any */
638 DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
643 /* Check the overall callout timeout */
645 if (time(NULL) - callout_start_time >= callout_overall)
647 HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
651 /* Set IPv4 or IPv6 */
653 host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
655 /* Expand and interpret the interface and port strings. The latter will not
656 be used if there is a host-specific port (e.g. from a manualroute router).
657 This has to be delayed till now, because they may expand differently for
658 different hosts. If there's a failure, log it, but carry on with the
661 deliver_host = host->name;
662 deliver_host_address = host->address;
663 deliver_host_port = host->port;
664 deliver_domain = addr->domain;
665 transport_name = addr->transport->name;
667 if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
669 || !smtp_get_port(tf->port, addr, &port, US"callout")
671 log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
674 if (!sx) sx = store_get(sizeof(*sx), TRUE); /* tainted buffers */
675 memset(sx, 0, sizeof(*sx));
677 sx->addrlist = sx->first_addr = addr;
678 sx->conn_args.host = host;
679 sx->conn_args.host_af = host_af,
681 sx->conn_args.interface = interface;
682 sx->helo_data = tf->helo_data;
683 sx->conn_args.tblock = addr->transport;
686 tls_retry_connection:
687 /* Set the address state so that errors are recorded in it */
689 addr->transport_return = PENDING_DEFER;
690 ob->connect_timeout = callout_connect;
691 ob->command_timeout = callout;
693 /* Get the channel set up ready for a message (MAIL FROM being the next
694 SMTP command to send. If we tried TLS but it failed, try again without
697 yield = smtp_setup_conn(sx, FALSE);
700 && addr->basic_errno == ERRNO_TLSFAILURE
701 && ob->tls_tempfail_tryclear
702 && verify_check_given_host(CUSS &ob->hosts_require_tls, host) != OK
705 log_write(0, LOG_MAIN,
706 "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
707 addr->message, host->name, host->address);
708 addr->transport_return = PENDING_DEFER;
709 yield = smtp_setup_conn(sx, TRUE);
714 errno = addr->basic_errno;
715 transport_name = NULL;
716 deliver_host = deliver_host_address = NULL;
717 deliver_domain = save_deliver_domain;
719 /* Failure to accept HELO is cached; this blocks the whole domain for all
720 senders. I/O errors and defer responses are not cached. */
722 if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
724 setflag(addr, af_verify_nsfail);
725 new_domain_record.result = ccache_reject;
733 /* If we needed to authenticate, smtp_setup_conn() did that. Copy
734 the AUTH info for logging */
736 addr->authenticator = client_authenticator;
737 addr->auth_id = client_authenticated_id;
739 sx->from_addr = from_address;
740 sx->first_addr = sx->sync_addr = addr;
741 sx->ok = FALSE; /*XXX these 3 last might not be needed for verify? */
742 sx->send_rset = TRUE;
743 sx->completed_addr = FALSE;
745 new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
746 ? ccache_reject_mfnull : ccache_accept;
748 /* Do the random local part check first. Temporarily replace the recipient
749 with the "random" value */
751 if (random_local_part)
753 uschar * main_address = addr->address;
754 const uschar * rcpt_domain = addr->domain;
757 uschar * errstr = NULL;
758 if ( testflag(addr, af_utf8_downcvt)
759 && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
763 addr->message = errstr;
764 errno = ERRNO_EXPANDFAIL;
765 setflag(addr, af_verify_nsfail);
767 rcpt_domain = US""; /*XXX errorhandling! */
771 /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
772 subsequents are done in cutthrough_multi()), but no way to
773 handle a subsequent because of the RSET vaporising the MAIL FROM.
774 So refuse to support any. Most cutthrough use will not involve
775 random_local_part, so no loss. */
776 cancel_cutthrough_connection(TRUE, US"random-recipient");
778 addr->address = string_sprintf("%s@%.1000s",
779 random_local_part, rcpt_domain);
782 /* If accepted, we aren't going to do any further tests below.
783 Otherwise, cache a real negative response, and get back to the right
784 state to send RCPT. Unless there's some problem such as a dropped
785 connection, we expect to succeed, because the commands succeeded above.
786 However, some servers drop the connection after responding to an
787 invalid recipient, so on (any) error we drop and remake the connection.
788 XXX We don't care about that for postmaster_full. Should we?
790 XXX could we add another flag to the context, and have the common
791 code emit the RSET too? Even pipelined after the RCPT...
792 Then the main-verify call could use it if there's to be a subsequent
794 The sync_responses() would need to be taught about it and we'd
795 need another return code filtering out to here.
797 Avoid using a SIZE option on the MAIL for all random-rcpt checks.
800 sx->avoid_option = OPTION_SIZE;
802 /* Remember when we last did a random test */
803 new_domain_record.random_stamp = time(NULL);
805 if (smtp_write_mail_and_rcpt_cmds(sx, &yield) == 0)
806 switch(addr->transport_return)
808 case PENDING_OK: /* random was accepted, unfortunately */
809 new_domain_record.random_result = ccache_accept;
810 yield = OK; /* Only usable verify result we can return */
812 *failure_ptr = US"random";
814 case FAIL: /* rejected: the preferred result */
815 new_domain_record.random_result = ccache_reject;
816 sx->avoid_option = 0;
818 /* Between each check, issue RSET, because some servers accept only
819 one recipient after MAIL FROM:<>.
820 XXX We don't care about that for postmaster_full. Should we? */
823 smtp_write_command(sx, SCMD_FLUSH, "RSET\r\n") >= 0 &&
824 smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', callout)))
828 debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
829 random_local_part = NULL;
831 tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
833 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
834 (void)close(sx->cctx.sock);
836 #ifndef DISABLE_EVENT
837 (void) event_raise(addr->transport->event_action,
838 US"tcp:close", NULL);
840 addr->address = main_address;
841 addr->transport_return = PENDING_DEFER;
842 sx->first_addr = sx->sync_addr = addr;
844 sx->send_rset = TRUE;
845 sx->completed_addr = FALSE;
846 goto tls_retry_connection;
847 case DEFER: /* 4xx response to random */
848 break; /* Just to be clear. ccache_unknown, !done. */
851 /* Re-setup for main verify, or for the error message when failing */
852 addr->address = main_address;
853 addr->transport_return = PENDING_DEFER;
854 sx->first_addr = sx->sync_addr = addr;
856 sx->send_rset = TRUE;
857 sx->completed_addr = FALSE;
862 /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
863 for sndr-verify never use it. */
867 if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
868 sx->avoid_option = OPTION_SIZE;
871 switch(smtp_write_mail_and_rcpt_cmds(sx, &yield))
873 case 0: switch(addr->transport_return) /* ok so far */
875 case PENDING_OK: done = TRUE;
876 new_address_record.result = ccache_accept;
878 case FAIL: done = TRUE;
880 *failure_ptr = US"recipient";
881 new_address_record.result = ccache_reject;
887 case -1: /* MAIL response error */
888 *failure_ptr = US"mail";
889 if (errno == 0 && sx->buffer[0] == '5')
891 setflag(addr, af_verify_nsfail);
892 if (from_address[0] == 0)
893 new_domain_record.result = ccache_reject_mfnull;
896 /* non-MAIL read i/o error */
897 /* non-MAIL response timeout */
898 /* internal error; channel still usable */
899 default: break; /* transmit failed */
903 addr->auth_sndr = client_authenticated_sender;
905 deliver_host = deliver_host_address = NULL;
906 deliver_domain = save_deliver_domain;
908 /* Do postmaster check if requested; if a full check is required, we
909 check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
911 if (done && pm_mailfrom)
913 /* Could possibly shift before main verify, just above, and be ok
914 for cutthrough. But no way to handle a subsequent rcpt, so just
916 cancel_cutthrough_connection(TRUE, US"postmaster verify");
917 HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
919 done = smtp_write_command(sx, SCMD_FLUSH, "RSET\r\n") >= 0
920 && smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', callout);
924 uschar * main_address = addr->address;
926 /*XXX oops, affixes */
927 addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
928 addr->transport_return = PENDING_DEFER;
930 sx->from_addr = pm_mailfrom;
931 sx->first_addr = sx->sync_addr = addr;
933 sx->send_rset = TRUE;
934 sx->completed_addr = FALSE;
935 sx->avoid_option = OPTION_SIZE;
937 if( smtp_write_mail_and_rcpt_cmds(sx, &yield) == 0
938 && addr->transport_return == PENDING_OK
942 done = (options & vopt_callout_fullpm) != 0
943 && smtp_write_command(sx, SCMD_FLUSH,
944 "RCPT TO:<postmaster>\r\n") >= 0
945 && smtp_read_response(sx, sx->buffer,
946 sizeof(sx->buffer), '2', callout);
948 /* Sort out the cache record */
950 new_domain_record.postmaster_stamp = time(NULL);
953 new_domain_record.postmaster_result = ccache_accept;
954 else if (errno == 0 && sx->buffer[0] == '5')
956 *failure_ptr = US"postmaster";
957 setflag(addr, af_verify_pmfail);
958 new_domain_record.postmaster_result = ccache_reject;
961 addr->address = main_address;
964 /* For any failure of the main check, other than a negative response, we just
965 close the connection and carry on. We can identify a negative response by the
966 fact that errno is zero. For I/O errors it will be non-zero
968 Set up different error texts for logging and for sending back to the caller
969 as an SMTP response. Log in all cases, using a one-line format. For sender
970 callouts, give a full response to the caller, but for recipient callouts,
971 don't give the IP address because this may be an internal host whose identity
972 is not to be widely broadcast. */
978 HDEBUG(D_verify) debug_printf("SMTP timeout\n");
979 sx->send_quit = FALSE;
985 extern int acl_where; /* src/acl.c */
987 addr->message = US"response to \"EHLO\" did not include SMTPUTF8";
988 addr->user_message = acl_where == ACL_WHERE_RCPT
989 ? US"533 no support for internationalised mailbox name"
990 : US"550 mailbox unavailable";
997 sx->send_quit = FALSE;
1001 if (*sx->buffer == 0) Ustrcpy(sx->buffer, US"connection dropped");
1003 /*XXX test here is ugly; seem to have a split of responsibility for
1004 building this message. Need to rationalise. Where is it done
1005 before here, and when not?
1006 Not == 5xx resp to MAIL on main-verify
1008 if (!addr->message) addr->message =
1009 string_sprintf("response to \"%s\" was: %s",
1010 big_buffer, string_printing(sx->buffer));
1012 /* RFC 5321 section 4.2: the text portion of the response may have only
1013 HT, SP, Printable US-ASCII. Deal with awkward chars by cutting the
1014 received message off before passing it onward. Newlines are ok; they
1015 just become a multiline response (but wrapped in the error code we
1018 for (uschar * s = sx->buffer;
1019 *s && s < sx->buffer + sizeof(sx->buffer);
1023 if (c != '\t' && c != '\n' && (c < ' ' || c > '~'))
1025 if (s - sx->buffer < sizeof(sx->buffer) - 12)
1026 memcpy(s, "(truncated)", 12);
1032 addr->user_message = options & vopt_is_recipient
1033 ? string_sprintf("Callout verification failed:\n%s", sx->buffer)
1034 : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
1035 host->address, big_buffer, sx->buffer);
1037 /* Hard rejection ends the process */
1039 if (sx->buffer[0] == '5') /* Address rejected */
1047 /* End the SMTP conversation and close the connection. */
1049 /* Cutthrough - on a successful connect and recipient-verify with
1050 use-sender and we are 1st rcpt and have no cutthrough conn so far
1051 here is where we want to leave the conn open. Ditto for a lazy-close
1054 if (cutthrough.delivery)
1056 if (addr->transport->filter_command)
1058 cutthrough.delivery= FALSE;
1059 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
1061 #ifndef DISABLE_DKIM
1062 if (ob->dkim.dkim_domain)
1064 cutthrough.delivery= FALSE;
1065 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
1068 #ifdef EXPERIMENTAL_ARC
1071 cutthrough.delivery= FALSE;
1072 HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of ARC signing\n");
1077 if ( (cutthrough.delivery || options & vopt_callout_hold)
1081 && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
1082 == vopt_callout_recipsender
1083 && !random_local_part
1085 && cutthrough.cctx.sock < 0
1089 HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
1091 ? "cutthrough delivery" : "potential further verifies and delivery");
1093 cutthrough.callout_hold_only = !cutthrough.delivery;
1094 cutthrough.is_tls = tls_out.active.sock >= 0;
1095 /* We assume no buffer in use in the outblock */
1096 cutthrough.cctx = sx->cctx;
1097 cutthrough.nrcpt = 1;
1098 cutthrough.transport = addr->transport->name;
1099 cutthrough.interface = interface;
1100 cutthrough.snd_port = sending_port;
1101 cutthrough.peer_options = smtp_peer_options;
1102 cutthrough.host = *host;
1104 int oldpool = store_pool;
1105 store_pool = POOL_PERM;
1106 cutthrough.snd_ip = string_copy(sending_ip_address);
1107 cutthrough.host.name = string_copy(host->name);
1108 cutthrough.host.address = string_copy(host->address);
1109 store_pool = oldpool;
1112 /* Save the address_item and parent chain for later logging */
1113 cutthrough.addr = *addr;
1114 cutthrough.addr.next = NULL;
1115 cutthrough.addr.host_used = &cutthrough.host;
1116 for (address_item * caddr = &cutthrough.addr, * parent = addr->parent;
1118 caddr = caddr->parent, parent = parent->parent)
1119 *(caddr->parent = store_get(sizeof(address_item), FALSE)) = *parent;
1121 ctctx.outblock.buffer = ctbuffer;
1122 ctctx.outblock.buffersize = sizeof(ctbuffer);
1123 ctctx.outblock.ptr = ctbuffer;
1124 /* ctctx.outblock.cmd_count = 0; ctctx.outblock.authenticating = FALSE; */
1125 ctctx.outblock.cctx = &cutthrough.cctx;
1129 /* Ensure no cutthrough on multiple verifies that were incompatible */
1130 if (options & vopt_callout_recipsender)
1131 cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
1133 if (smtp_write_command(sx, SCMD_FLUSH, "QUIT\r\n") != -1)
1134 /* Wait a short time for response, and discard it */
1135 smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', 1);
1137 if (sx->cctx.sock >= 0)
1140 if (sx->cctx.tls_ctx)
1142 tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1143 sx->cctx.tls_ctx = NULL;
1146 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1147 (void)close(sx->cctx.sock);
1149 #ifndef DISABLE_EVENT
1150 (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
1155 if (!done || yield != OK)
1156 addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
1158 } /* Loop through all hosts, while !done */
1161 /* If we get here with done == TRUE, a successful callout happened, and yield
1162 will be set OK or FAIL according to the response to the RCPT command.
1163 Otherwise, we looped through the hosts but couldn't complete the business.
1164 However, there may be domain-specific information to cache in both cases. */
1166 if (!(options & vopt_callout_no_cache))
1167 cache_callout_write(&new_domain_record, addr->domain,
1168 done, &new_address_record, address_key);
1170 /* Failure to connect to any host, or any response other than 2xx or 5xx is a
1171 temporary error. If there was only one host, and a response was received, leave
1172 it alone if supplying details. Otherwise, give a generic response. */
1176 uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
1177 options & vopt_is_recipient ? "recipient" : "sender");
1180 addr->message = host_list->next || !addr->message
1181 ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
1183 addr->user_message = smtp_return_error_details
1184 ? string_sprintf("%s for <%s>.\n"
1185 "The mail server(s) for the domain may be temporarily unreachable, or\n"
1186 "they may be permanently unreachable from this server. In the latter case,\n%s",
1187 dullmsg, addr->address,
1188 options & vopt_is_recipient
1189 ? "the address will never be accepted."
1190 : "you need to change the address or create an MX record for its domain\n"
1191 "if it is supposed to be generally accessible from the Internet.\n"
1192 "Talk to your mail administrator for details.")
1195 /* Force a specific error code */
1197 addr->basic_errno = ERRNO_CALLOUTDEFER;
1200 /* Come here from within the cache-reading code on fast-track exit. */
1203 tls_modify_variables(&tls_in); /* return variables to inbound values */
1209 /* Called after recipient-acl to get a cutthrough connection open when
1210 one was requested and a recipient-verify wasn't subsequently done.
1213 open_cutthrough_connection(address_item * addr)
1218 /* Use a recipient-verify-callout to set up the cutthrough connection. */
1219 /* We must use a copy of the address for verification, because it might
1223 HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
1224 rcpt_count > 1 ? "more" : "start");
1225 rc = verify_address(&addr2, NULL,
1226 vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
1227 CUTTHROUGH_CMD_TIMEOUT, -1, -1,
1229 addr->message = addr2.message;
1230 addr->user_message = addr2.user_message;
1231 HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
1237 /* Send given number of bytes from the buffer */
1239 cutthrough_send(int n)
1241 if(cutthrough.cctx.sock < 0)
1247 ? tls_write(cutthrough.cctx.tls_ctx, ctctx.outblock.buffer, n, FALSE)
1250 send(cutthrough.cctx.sock, ctctx.outblock.buffer, n, 0) > 0
1253 transport_count += n;
1254 ctctx.outblock.ptr= ctctx.outblock.buffer;
1258 HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
1265 _cutthrough_puts(uschar * cp, int n)
1269 if(ctctx.outblock.ptr >= ctctx.outblock.buffer+ctctx.outblock.buffersize)
1270 if(!cutthrough_send(ctctx.outblock.buffersize))
1273 *ctctx.outblock.ptr++ = *cp++;
1278 /* Buffered output of counted data block. Return boolean success */
1280 cutthrough_puts(uschar * cp, int n)
1282 if (cutthrough.cctx.sock < 0) return TRUE;
1283 if (_cutthrough_puts(cp, n)) return TRUE;
1284 cancel_cutthrough_connection(TRUE, US"transmit failed");
1289 cutthrough_data_puts(uschar * cp, int n)
1291 if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
1297 _cutthrough_flush_send(void)
1299 int n = ctctx.outblock.ptr - ctctx.outblock.buffer;
1302 if(!cutthrough_send(n))
1308 /* Send out any bufferred output. Return boolean success. */
1310 cutthrough_flush_send(void)
1312 if (_cutthrough_flush_send()) return TRUE;
1313 cancel_cutthrough_connection(TRUE, US"transmit failed");
1319 cutthrough_put_nl(void)
1321 return cutthrough_puts(US"\r\n", 2);
1326 cutthrough_data_put_nl(void)
1328 cutthrough_data_puts(US"\r\n", 2);
1332 /* Get and check response from cutthrough target */
1334 cutthrough_response(client_conn_ctx * cctx, char expect, uschar ** copy, int timeout)
1336 smtp_context sx = {0};
1337 uschar inbuffer[4096];
1338 uschar responsebuffer[4096];
1340 sx.inblock.buffer = inbuffer;
1341 sx.inblock.buffersize = sizeof(inbuffer);
1342 sx.inblock.ptr = inbuffer;
1343 sx.inblock.ptrend = inbuffer;
1344 sx.inblock.cctx = cctx;
1345 if(!smtp_read_response(&sx, responsebuffer, sizeof(responsebuffer), expect, timeout))
1346 cancel_cutthrough_connection(TRUE, US"target timeout on read");
1351 *copy = cp = string_copy(responsebuffer);
1352 /* Trim the trailing end of line */
1353 cp += Ustrlen(responsebuffer);
1354 if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
1355 if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
1358 return responsebuffer[0];
1362 /* Negotiate dataphase with the cutthrough target, returning success boolean */
1364 cutthrough_predata(void)
1366 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1369 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
1370 cutthrough_puts(US"DATA\r\n", 6);
1371 cutthrough_flush_send();
1373 /* Assume nothing buffered. If it was it gets ignored. */
1374 return cutthrough_response(&cutthrough.cctx, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
1378 /* tctx arg only to match write_chunk() */
1380 cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
1383 while(s && (s2 = Ustrchr(s, '\n')))
1385 if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
1393 /* Buffered send of headers. Return success boolean. */
1394 /* Expands newlines to wire format (CR,NL). */
1395 /* Also sends header-terminating blank line. */
1397 cutthrough_headers_send(void)
1401 if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
1404 /* We share a routine with the mainline transport to handle header add/remove/rewrites,
1405 but having a separate buffered-output function (for now)
1407 HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
1409 tctx.u.fd = cutthrough.cctx.sock;
1410 tctx.tblock = cutthrough.addr.transport;
1411 tctx.addr = &cutthrough.addr;
1412 tctx.check_string = US".";
1413 tctx.escape_string = US"..";
1414 /*XXX check under spool_files_wireformat. Might be irrelevant */
1415 tctx.options = topt_use_crlf;
1417 if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
1420 HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
1426 close_cutthrough_connection(const uschar * why)
1428 int fd = cutthrough.cctx.sock;
1431 /* We could be sending this after a bunch of data, but that is ok as
1432 the only way to cancel the transfer in dataphase is to drop the tcp
1433 conn before the final dot.
1435 client_conn_ctx tmp_ctx = cutthrough.cctx;
1436 ctctx.outblock.ptr = ctbuffer;
1437 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
1438 _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
1439 _cutthrough_flush_send();
1440 cutthrough.cctx.sock = -1; /* avoid recursion via read timeout */
1441 cutthrough.nrcpt = 0; /* permit re-cutthrough on subsequent message */
1443 /* Wait a short time for response, and discard it */
1444 cutthrough_response(&tmp_ctx, '2', NULL, 1);
1447 if (cutthrough.is_tls)
1449 tls_close(cutthrough.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
1450 cutthrough.cctx.tls_ctx = NULL;
1451 cutthrough.is_tls = FALSE;
1454 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
1456 HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
1458 ctctx.outblock.ptr = ctbuffer;
1462 cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
1464 if (cutthrough.delivery || close_noncutthrough_verifies)
1465 close_cutthrough_connection(why);
1466 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1471 release_cutthrough_connection(const uschar * why)
1473 if (cutthrough.cctx.sock < 0) return;
1474 HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
1475 cutthrough.cctx.sock = -1;
1476 cutthrough.cctx.tls_ctx = NULL;
1477 cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
1483 /* Have senders final-dot. Send one to cutthrough target, and grab the response.
1484 Log an OK response as a transmission.
1485 Close the connection.
1486 Return smtp response-class digit.
1489 cutthrough_finaldot(void)
1492 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
1494 /* Assume data finshed with new-line */
1495 if( !cutthrough_puts(US".", 1)
1496 || !cutthrough_put_nl()
1497 || !cutthrough_flush_send()
1499 return cutthrough.addr.message;
1501 res = cutthrough_response(&cutthrough.cctx, '2', &cutthrough.addr.message,
1502 CUTTHROUGH_DATA_TIMEOUT);
1503 for (address_item * addr = &cutthrough.addr; addr; addr = addr->next)
1505 addr->message = cutthrough.addr.message;
1509 delivery_log(LOG_MAIN, addr, (int)'>', NULL);
1510 close_cutthrough_connection(US"delivered");
1514 delivery_log(LOG_MAIN, addr, 0,
1515 US"tmp-reject from cutthrough after DATA:");
1519 delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
1520 US"rejected after DATA:");
1527 return cutthrough.addr.message;
1532 /*************************************************
1533 * Copy error to toplevel address *
1534 *************************************************/
1536 /* This function is used when a verify fails or defers, to ensure that the
1537 failure or defer information is in the original toplevel address. This applies
1538 when an address is redirected to a single new address, and the failure or
1539 deferral happens to the child address.
1542 vaddr the verify address item
1543 addr the final address item
1546 Returns: the value of YIELD
1550 copy_error(address_item *vaddr, address_item *addr, int yield)
1554 vaddr->message = addr->message;
1555 vaddr->user_message = addr->user_message;
1556 vaddr->basic_errno = addr->basic_errno;
1557 vaddr->more_errno = addr->more_errno;
1558 vaddr->prop.address_data = addr->prop.address_data;
1559 vaddr->prop.variables = NULL;
1560 tree_dup((tree_node **)&vaddr->prop.variables, addr->prop.variables);
1561 copyflag(vaddr, addr, af_pass_message);
1569 /**************************************************
1570 * printf that automatically handles TLS if needed *
1571 ***************************************************/
1573 /* This function is used by verify_address() as a substitute for all fprintf()
1574 calls; a direct fprintf() will not produce output in a TLS SMTP session, such
1575 as a response to an EXPN command. smtp_in.c makes smtp_printf available but
1576 that assumes that we always use the smtp_out FILE* when not using TLS or the
1577 ssl buffer when we are. Instead we take a FILE* parameter and check to see if
1578 that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
1582 f the candidate FILE* to write to
1583 format format string
1584 ... optional arguments
1590 static void PRINTF_FUNCTION(2,3)
1591 respond_printf(FILE *f, const char *format, ...)
1595 va_start(ap, format);
1596 if (smtp_out && (f == smtp_out))
1597 smtp_vprintf(format, FALSE, ap);
1599 vfprintf(f, format, ap);
1605 /*************************************************
1606 * Verify an email address *
1607 *************************************************/
1609 /* This function is used both for verification (-bv and at other times) and
1610 address testing (-bt), which is indicated by address_test_mode being set.
1613 vaddr contains the address to verify; the next field in this block
1615 f if not NULL, write the result to this file
1616 options various option bits:
1617 vopt_fake_sender => this sender verify is not for the real
1618 sender (it was verify=sender=xxxx or an address from a
1619 header line) - rewriting must not change sender_address
1620 vopt_is_recipient => this is a recipient address, otherwise
1621 it's a sender address - this affects qualification and
1622 rewriting and messages from callouts
1623 vopt_qualify => qualify an unqualified address; else error
1624 vopt_expn => called from SMTP EXPN command
1625 vopt_success_on_redirect => when a new address is generated
1626 the verification instantly succeeds
1628 These ones are used by do_callout() -- the options variable
1631 vopt_callout_fullpm => if postmaster check, do full one
1632 vopt_callout_no_cache => don't use callout cache
1633 vopt_callout_random => do the "random" thing
1634 vopt_callout_recipsender => use real sender for recipient
1635 vopt_callout_recippmaster => use postmaster for recipient
1637 callout if > 0, specifies that callout is required, and gives timeout
1638 for individual commands
1639 callout_overall if > 0, gives overall timeout for the callout function;
1640 if < 0, a default is used (see do_callout())
1641 callout_connect the connection timeout for callouts
1642 se_mailfrom when callout is requested to verify a sender, use this
1643 in MAIL FROM; NULL => ""
1644 pm_mailfrom when callout is requested, if non-NULL, do the postmaster
1645 thing and use this as the sender address (may be "")
1647 routed if not NULL, set TRUE if routing succeeded, so we can
1648 distinguish between routing failed and callout failed
1650 Returns: OK address verified
1651 FAIL address failed to verify
1652 DEFER can't tell at present
1656 verify_address(address_item * vaddr, FILE * fp, int options, int callout,
1657 int callout_overall, int callout_connect, uschar * se_mailfrom,
1658 uschar *pm_mailfrom, BOOL *routed)
1661 BOOL full_info = fp ? debug_selector != 0 : FALSE;
1662 BOOL expn = (options & vopt_expn) != 0;
1663 BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
1666 int verify_type = expn? v_expn :
1667 f.address_test_mode? v_none :
1668 options & vopt_is_recipient? v_recipient : v_sender;
1669 address_item *addr_list;
1670 address_item *addr_new = NULL;
1671 address_item *addr_remote = NULL;
1672 address_item *addr_local = NULL;
1673 address_item *addr_succeed = NULL;
1674 uschar **failure_ptr = options & vopt_is_recipient
1675 ? &recipient_verify_failure : &sender_verify_failure;
1676 uschar *ko_prefix, *cr;
1677 uschar *address = vaddr->address;
1678 uschar *save_sender;
1679 uschar null_sender[] = { 0 }; /* Ensure writeable memory */
1681 /* Clear, just in case */
1683 *failure_ptr = NULL;
1685 /* Set up a prefix and suffix for error message which allow us to use the same
1686 output statements both in EXPN mode (where an SMTP response is needed) and when
1687 debugging with an output file. */
1691 ko_prefix = US"553 ";
1694 else ko_prefix = cr = US"";
1696 /* Add qualify domain if permitted; otherwise an unqualified address fails. */
1698 if (parse_find_at(address) == NULL)
1700 if (!(options & vopt_qualify))
1703 respond_printf(fp, "%sA domain is required for \"%s\"%s\n",
1704 ko_prefix, address, cr);
1705 *failure_ptr = US"qualify";
1708 /* deconst ok as address was not const */
1709 address = US rewrite_address_qualify(address, options & vopt_is_recipient);
1714 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1715 debug_printf("%s %s\n", f.address_test_mode? "Testing" : "Verifying", address);
1718 /* Rewrite and report on it. Clear the domain and local part caches - these
1719 may have been set by domains and local part tests during an ACL. */
1721 if (global_rewrite_rules)
1723 uschar *old = address;
1724 /* deconst ok as address was not const */
1725 address = US rewrite_address(address, options & vopt_is_recipient, FALSE,
1726 global_rewrite_rules, rewrite_existflags);
1729 for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
1730 for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
1731 if (fp && !expn) fprintf(fp, "Address rewritten as: %s\n", address);
1735 /* If this is the real sender address, we must update sender_address at
1736 this point, because it may be referred to in the routers. */
1738 if (!(options & (vopt_fake_sender|vopt_is_recipient)))
1739 sender_address = address;
1741 /* If the address was rewritten to <> no verification can be done, and we have
1742 to return OK. This rewriting is permitted only for sender addresses; for other
1743 addresses, such rewriting fails. */
1745 if (!address[0]) return OK;
1747 /* Flip the legacy TLS-related variables over to the outbound set in case
1748 they're used in the context of a transport used by verification. Reset them
1749 at exit from this routine (so no returns allowed from here on). */
1751 tls_modify_variables(&tls_out);
1753 /* Save a copy of the sender address for re-instating if we change it to <>
1754 while verifying a sender address (a nice bit of self-reference there). */
1756 save_sender = sender_address;
1758 /* Observability variable for router/transport use */
1760 verify_mode = options & vopt_is_recipient ? US"R" : US"S";
1762 /* Update the address structure with the possibly qualified and rewritten
1763 address. Set it up as the starting address on the chain of new addresses. */
1765 vaddr->address = address;
1768 /* We need a loop, because an address can generate new addresses. We must also
1769 cope with generated pipes and files at the top level. (See also the code and
1770 comment in deliver.c.) However, it is usually the case that the router for
1771 user's .forward files has its verify flag turned off.
1773 If an address generates more than one child, the loop is used only when
1774 full_info is set, and this can only be set locally. Remote enquiries just get
1775 information about the top level address, not anything that it generated. */
1780 address_item *addr = addr_new;
1782 addr_new = addr->next;
1787 debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
1788 debug_printf("Considering %s\n", addr->address);
1791 /* Handle generated pipe, file or reply addresses. We don't get these
1792 when handling EXPN, as it does only one level of expansion. */
1794 if (testflag(addr, af_pfr))
1801 if (addr->address[0] == '>')
1803 allow = testflag(addr, af_allow_reply);
1804 fprintf(fp, "%s -> mail %s", addr->parent->address, addr->address + 1);
1808 allow = addr->address[0] == '|'
1809 ? testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
1810 fprintf(fp, "%s -> %s", addr->parent->address, addr->address);
1813 if (addr->basic_errno == ERRNO_BADTRANSPORT)
1814 fprintf(fp, "\n*** Error in setting up pipe, file, or autoreply:\n"
1815 "%s\n", addr->message);
1817 fprintf(fp, "\n transport = %s\n", addr->transport->name);
1819 fprintf(fp, " *** forbidden ***\n");
1824 /* Just in case some router parameter refers to it. */
1826 return_path = addr->prop.errors_address
1827 ? addr->prop.errors_address : sender_address;
1829 /* Split the address into domain and local part, handling the %-hack if
1830 necessary, and then route it. While routing a sender address, set
1831 $sender_address to <> because that is what it will be if we were trying to
1832 send a bounce to the sender. */
1834 if (routed) *routed = FALSE;
1835 if ((rc = deliver_split_address(addr)) == OK)
1837 if (!(options & vopt_is_recipient)) sender_address = null_sender;
1838 rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
1839 &addr_succeed, verify_type);
1840 sender_address = save_sender; /* Put back the real sender */
1843 /* If routing an address succeeded, set the flag that remembers, for use when
1844 an ACL cached a sender verify (in case a callout fails). Then if routing set
1845 up a list of hosts or the transport has a host list, and the callout option
1846 is set, and we aren't in a host checking run, do the callout verification,
1847 and set another flag that notes that a callout happened. */
1851 if (routed) *routed = TRUE;
1854 transport_instance * tp;
1855 host_item * host_list = addr->host_list;
1857 /* Make up some data for use in the case where there is no remote
1860 transport_feedback tf = {
1861 .interface = NULL, /* interface (=> any) */
1863 .protocol = US"smtp",
1865 .helo_data = US"$smtp_active_hostname",
1866 .hosts_override = FALSE,
1867 .hosts_randomize = FALSE,
1868 .gethostbyname = FALSE,
1869 .qualify_single = TRUE,
1870 .search_parents = FALSE
1873 /* If verification yielded a remote transport, we want to use that
1874 transport's options, so as to mimic what would happen if we were really
1875 sending a message to this address. */
1877 if ((tp = addr->transport) && !tp->info->local)
1879 (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
1881 /* If the transport has hosts and the router does not, or if the
1882 transport is configured to override the router's hosts, we must build a
1883 host list of the transport's hosts, and find the IP addresses */
1885 if (tf.hosts && (!host_list || tf.hosts_override))
1888 const uschar *save_deliver_domain = deliver_domain;
1889 uschar *save_deliver_localpart = deliver_localpart;
1891 host_list = NULL; /* Ignore the router's hosts */
1893 deliver_domain = addr->domain;
1894 deliver_localpart = addr->local_part;
1895 s = expand_string(tf.hosts);
1896 deliver_domain = save_deliver_domain;
1897 deliver_localpart = save_deliver_localpart;
1901 log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
1902 "\"%s\" in %s transport for callout: %s", tf.hosts,
1903 tp->name, expand_string_message);
1908 host_build_hostlist(&host_list, s, tf.hosts_randomize);
1910 /* Just ignore failures to find a host address. If we don't manage
1911 to find any addresses, the callout will defer. Note that more than
1912 one address may be found for a single host, which will result in
1913 additional host items being inserted into the chain. Hence we must
1914 save the next host first. */
1916 flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
1917 if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
1918 if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
1920 for (host_item * host = host_list, * nexthost; host; host = nexthost)
1922 nexthost = host->next;
1923 if (tf.gethostbyname ||
1924 string_is_ip_address(host->name, NULL) != 0)
1925 (void)host_find_byname(host, NULL, flags, NULL, TRUE);
1928 const dnssec_domains * dsp = NULL;
1929 if (Ustrcmp(tp->driver_name, "smtp") == 0)
1931 smtp_transport_options_block * ob =
1932 (smtp_transport_options_block *) tp->options_block;
1936 (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
1944 /* Can only do a callout if we have at least one host! If the callout
1945 fails, it will have set ${sender,recipient}_verify_failure. */
1949 HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
1950 if (host_checking && !f.host_checking_callout)
1953 debug_printf("... callout omitted by default when host testing\n"
1954 "(Use -bhc if you want the callouts to happen.)\n");
1959 deliver_set_expansions(addr);
1961 rc = do_callout(addr, host_list, &tf, callout, callout_overall,
1962 callout_connect, options, se_mailfrom, pm_mailfrom);
1964 deliver_set_expansions(NULL);
1970 HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
1971 "transport provided a host list, or transport is not smtp\n");
1976 /* Otherwise, any failure is a routing failure */
1978 else *failure_ptr = US"route";
1980 /* A router may return REROUTED if it has set up a child address as a result
1981 of a change of domain name (typically from widening). In this case we always
1982 want to continue to verify the new child. */
1984 if (rc == REROUTED) continue;
1986 /* Handle hard failures */
1993 address_item *p = addr->parent;
1995 respond_printf(fp, "%s%s %s", ko_prefix,
1996 full_info ? addr->address : address,
1997 f.address_test_mode ? "is undeliverable" : "failed to verify");
1998 if (!expn && f.admin_user)
2000 if (addr->basic_errno > 0)
2001 respond_printf(fp, ": %s", strerror(addr->basic_errno));
2003 respond_printf(fp, ": %s", addr->message);
2006 /* Show parents iff doing full info */
2008 if (full_info) while (p)
2010 respond_printf(fp, "%s\n <-- %s", cr, p->address);
2013 respond_printf(fp, "%s\n", cr);
2015 cancel_cutthrough_connection(TRUE, US"routing hard fail");
2019 yield = copy_error(vaddr, addr, FAIL);
2027 else if (rc == DEFER)
2032 address_item *p = addr->parent;
2033 respond_printf(fp, "%s%s cannot be resolved at this time", ko_prefix,
2034 full_info? addr->address : address);
2035 if (!expn && f.admin_user)
2037 if (addr->basic_errno > 0)
2038 respond_printf(fp, ": %s", strerror(addr->basic_errno));
2040 respond_printf(fp, ": %s", addr->message);
2041 else if (addr->basic_errno <= 0)
2042 respond_printf(fp, ": unknown error");
2045 /* Show parents iff doing full info */
2047 if (full_info) while (p)
2049 respond_printf(fp, "%s\n <-- %s", cr, p->address);
2052 respond_printf(fp, "%s\n", cr);
2054 cancel_cutthrough_connection(TRUE, US"routing soft fail");
2058 yield = copy_error(vaddr, addr, DEFER);
2061 if (yield == OK) yield = DEFER;
2064 /* If we are handling EXPN, we do not want to continue to route beyond
2065 the top level (whose address is in "address"). */
2069 uschar *ok_prefix = US"250-";
2072 if (!addr_local && !addr_remote)
2073 respond_printf(fp, "250 mail to <%s> is discarded\r\n", address);
2075 respond_printf(fp, "250 <%s>\r\n", address);
2079 address_item *addr2 = addr_new;
2080 addr_new = addr2->next;
2081 if (!addr_new) ok_prefix = US"250 ";
2082 respond_printf(fp, "%s<%s>\r\n", ok_prefix, addr2->address);
2088 /* Successful routing other than EXPN. */
2092 /* Handle successful routing when short info wanted. Otherwise continue for
2093 other (generated) addresses. Short info is the operational case. Full info
2094 can be requested only when debug_selector != 0 and a file is supplied.
2096 There is a conflict between the use of aliasing as an alternate email
2097 address, and as a sort of mailing list. If an alias turns the incoming
2098 address into just one address (e.g. J.Caesar->jc44) you may well want to
2099 carry on verifying the generated address to ensure it is valid when
2100 checking incoming mail. If aliasing generates multiple addresses, you
2101 probably don't want to do this. Exim therefore treats the generation of
2102 just a single new address as a special case, and continues on to verify the
2103 generated address. */
2105 if ( !full_info /* Stop if short info wanted AND */
2106 && ( ( !addr_new /* No new address OR */
2107 || addr_new->next /* More than one new address OR */
2108 || testflag(addr_new, af_pfr) /* New address is pfr */
2111 ( addr_new /* At least one new address AND */
2112 && success_on_redirect /* success_on_redirect is set */
2116 if (fp) fprintf(fp, "%s %s\n",
2117 address, f.address_test_mode ? "is deliverable" : "verified");
2119 /* If we have carried on to verify a child address, we want the value
2120 of $address_data to be that of the child */
2122 vaddr->prop.address_data = addr->prop.address_data;
2123 vaddr->prop.variables = NULL;
2124 tree_dup((tree_node **)&vaddr->prop.variables, addr->prop.variables);
2126 /* If stopped because more than one new address, cannot cutthrough */
2128 if (addr_new && addr_new->next)
2129 cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
2135 } /* Loop for generated addresses */
2137 /* Display the full results of the successful routing, including any generated
2138 addresses. Control gets here only when full_info is set, which requires fp not
2139 to be NULL, and this occurs only when a top-level verify is called with the
2140 debugging switch on.
2142 If there are no local and no remote addresses, and there were no pipes, files,
2143 or autoreplies, and there were no errors or deferments, the message is to be
2144 discarded, usually because of the use of :blackhole: in an alias file. */
2146 if (allok && !addr_local && !addr_remote)
2148 fprintf(fp, "mail to %s is discarded\n", address);
2152 for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
2155 address_item *addr = addr_list;
2156 transport_instance * tp = addr->transport;
2158 addr_list = addr->next;
2160 fprintf(fp, "%s", CS addr->address);
2161 #ifdef EXPERIMENTAL_SRS
2162 if(addr->prop.srs_sender)
2163 fprintf(fp, " [srs = %s]", addr->prop.srs_sender);
2166 /* If the address is a duplicate, show something about it. */
2168 if (!testflag(addr, af_pfr))
2171 if ((tnode = tree_search(tree_duplicates, addr->unique)))
2172 fprintf(fp, " [duplicate, would not be delivered]");
2173 else tree_add_duplicate(addr->unique, addr);
2176 /* Now show its parents */
2178 for (address_item * p = addr->parent; p; p = p->parent)
2179 fprintf(fp, "\n <-- %s", p->address);
2182 /* Show router, and transport */
2184 fprintf(fp, "router = %s, transport = %s\n",
2185 addr->router->name, tp ? tp->name : US"unset");
2187 /* Show any hosts that are set up by a router unless the transport
2188 is going to override them; fiddle a bit to get a nice format. */
2190 if (addr->host_list && tp && !tp->overrides_hosts)
2194 for (host_item * h = addr->host_list; h; h = h->next)
2195 { /* get max lengths of host names, addrs */
2196 int len = Ustrlen(h->name);
2197 if (len > maxlen) maxlen = len;
2198 len = h->address ? Ustrlen(h->address) : 7;
2199 if (len > maxaddlen) maxaddlen = len;
2201 for (host_item * h = addr->host_list; h; h = h->next)
2203 fprintf(fp, " host %-*s ", maxlen, h->name);
2206 fprintf(fp, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
2207 else if (tp->info->local)
2208 fprintf(fp, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
2210 fprintf(fp, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
2212 if (h->mx >= 0) fprintf(fp, " MX=%d", h->mx);
2213 if (h->port != PORT_NONE) fprintf(fp, " port=%d", h->port);
2214 if (f.running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", fp);
2215 if (h->status == hstatus_unusable) fputs(" ** unusable **", fp);
2221 /* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
2222 the -bv or -bt case). */
2226 tls_modify_variables(&tls_in); /* return variables to inbound values */
2234 /*************************************************
2235 * Check headers for syntax errors *
2236 *************************************************/
2238 /* This function checks those header lines that contain addresses, and verifies
2239 that all the addresses therein are 5322-syntactially correct.
2242 msgptr where to put an error message
2249 verify_check_headers(uschar **msgptr)
2254 for (header_line * h = header_list; h && yield == OK; h = h->next)
2256 if (h->type != htype_from &&
2257 h->type != htype_reply_to &&
2258 h->type != htype_sender &&
2259 h->type != htype_to &&
2260 h->type != htype_cc &&
2261 h->type != htype_bcc)
2264 colon = Ustrchr(h->text, ':');
2266 Uskip_whitespace(&s);
2268 /* Loop for multiple addresses in the header, enabling group syntax. Note
2269 that we have to reset this after the header has been scanned. */
2271 f.parse_allow_group = TRUE;
2275 uschar *ss = parse_find_address_end(s, FALSE);
2276 uschar *recipient, *errmess;
2277 int terminator = *ss;
2278 int start, end, domain;
2280 /* Temporarily terminate the string at this point, and extract the
2281 operative address within, allowing group syntax. */
2284 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2287 /* Permit an unqualified address only if the message is local, or if the
2288 sending host is configured to be permitted to send them. */
2290 if (recipient && !domain)
2292 if (h->type == htype_from || h->type == htype_sender)
2294 if (!f.allow_unqualified_sender) recipient = NULL;
2298 if (!f.allow_unqualified_recipient) recipient = NULL;
2300 if (!recipient) errmess = US"unqualified address not permitted";
2303 /* It's an error if no address could be extracted, except for the special
2304 case of an empty address. */
2306 if (!recipient && Ustrcmp(errmess, "empty address") != 0)
2308 uschar *verb = US"is";
2313 /* Arrange not to include any white space at the end in the
2314 error message or the header name. */
2316 while (t > s && isspace(t[-1])) t--;
2317 while (tt > h->text && isspace(tt[-1])) tt--;
2319 /* Add the address that failed to the error message, since in a
2320 header with very many addresses it is sometimes hard to spot
2321 which one is at fault. However, limit the amount of address to
2322 quote - cases have been seen where, for example, a missing double
2323 quote in a humungous To: header creates an "address" that is longer
2324 than string_sprintf can handle. */
2333 /* deconst cast ok as we're passing a non-const to string_printing() */
2334 *msgptr = US string_printing(
2335 string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
2336 errmess, (int)(tt - h->text), h->text, verb, len, s));
2339 break; /* Out of address loop */
2342 /* Advance to the next address */
2344 s = ss + (terminator ? 1 : 0);
2345 Uskip_whitespace(&s);
2346 } /* Next address */
2348 f.parse_allow_group = FALSE;
2349 f.parse_found_group = FALSE;
2350 } /* Next header unless yield has been set FALSE */
2356 /*************************************************
2357 * Check header names for 8-bit characters *
2358 *************************************************/
2360 /* This function checks for invalid characters in header names. See
2361 RFC 5322, 2.2. and RFC 6532, 3.
2364 msgptr where to put an error message
2371 verify_check_header_names_ascii(uschar **msgptr)
2375 for (header_line * h = header_list; h; h = h->next)
2377 colon = Ustrchr(h->text, ':');
2378 for(uschar * s = h->text; s < colon; s++)
2379 if ((*s < 33) || (*s > 126))
2381 *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
2382 (int)(colon - h->text), h->text);
2389 /*************************************************
2390 * Check for blind recipients *
2391 *************************************************/
2393 /* This function checks that every (envelope) recipient is mentioned in either
2394 the To: or Cc: header lines, thus detecting blind carbon copies.
2396 There are two ways of scanning that could be used: either scan the header lines
2397 and tick off the recipients, or scan the recipients and check the header lines.
2398 The original proposed patch did the former, but I have chosen to do the latter,
2399 because (a) it requires no memory and (b) will use fewer resources when there
2400 are many addresses in To: and/or Cc: and only one or two envelope recipients.
2402 Arguments: case_sensitive true if case sensitive matching should be used
2403 Returns: OK if there are no blind recipients
2404 FAIL if there is at least one blind recipient
2408 verify_check_notblind(BOOL case_sensitive)
2410 for (int i = 0; i < recipients_count; i++)
2413 uschar *address = recipients_list[i].address;
2415 for (header_line * h = header_list; !found && h; h = h->next)
2419 if (h->type != htype_to && h->type != htype_cc) continue;
2421 colon = Ustrchr(h->text, ':');
2423 Uskip_whitespace(&s);
2425 /* Loop for multiple addresses in the header, enabling group syntax. Note
2426 that we have to reset this after the header has been scanned. */
2428 f.parse_allow_group = TRUE;
2432 uschar * ss = parse_find_address_end(s, FALSE);
2433 uschar * recipient, * errmess;
2434 int terminator = *ss;
2435 int start, end, domain;
2437 /* Temporarily terminate the string at this point, and extract the
2438 operative address within, allowing group syntax. */
2441 recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
2444 /* If we found a valid recipient that has a domain, compare it with the
2445 envelope recipient. Local parts are compared with case-sensitivity
2446 according to the routine arg, domains case-insensitively.
2447 By comparing from the start with length "domain", we include the "@" at
2448 the end, which ensures that we are comparing the whole local part of each
2451 if (recipient && domain != 0)
2452 if ((found = (case_sensitive
2453 ? Ustrncmp(recipient, address, domain) == 0
2454 : strncmpic(recipient, address, domain) == 0)
2455 && strcmpic(recipient + domain, address + domain) == 0))
2458 /* Advance to the next address */
2460 s = ss + (terminator ? 1:0);
2461 Uskip_whitespace(&s);
2462 } /* Next address */
2464 f.parse_allow_group = FALSE;
2465 f.parse_found_group = FALSE;
2466 } /* Next header (if found is false) */
2468 if (!found) return FAIL;
2469 } /* Next recipient */
2476 /*************************************************
2477 * Find if verified sender *
2478 *************************************************/
2480 /* Usually, just a single address is verified as the sender of the message.
2481 However, Exim can be made to verify other addresses as well (often related in
2482 some way), and this is useful in some environments. There may therefore be a
2483 chain of such addresses that have previously been tested. This function finds
2484 whether a given address is on the chain.
2486 Arguments: the address to be verified
2487 Returns: pointer to an address item, or NULL
2491 verify_checked_sender(uschar *sender)
2493 for (address_item * addr = sender_verified_list; addr; addr = addr->next)
2494 if (Ustrcmp(sender, addr->address) == 0) return addr;
2502 /*************************************************
2503 * Get valid header address *
2504 *************************************************/
2506 /* Scan the originator headers of the message, looking for an address that
2507 verifies successfully. RFC 822 says:
2509 o The "Sender" field mailbox should be sent notices of
2510 any problems in transport or delivery of the original
2511 messages. If there is no "Sender" field, then the
2512 "From" field mailbox should be used.
2514 o If the "Reply-To" field exists, then the reply should
2515 go to the addresses indicated in that field and not to
2516 the address(es) indicated in the "From" field.
2518 So we check a Sender field if there is one, else a Reply_to field, else a From
2519 field. As some strange messages may have more than one of these fields,
2520 especially if they are resent- fields, check all of them if there is more than
2524 user_msgptr points to where to put a user error message
2525 log_msgptr points to where to put a log error message
2526 callout timeout for callout check (passed to verify_address())
2527 callout_overall overall callout timeout (ditto)
2528 callout_connect connect callout timeout (ditto)
2529 se_mailfrom mailfrom for verify; NULL => ""
2530 pm_mailfrom sender for pm callout check (passed to verify_address())
2531 options callout options (passed to verify_address())
2532 verrno where to put the address basic_errno
2534 If log_msgptr is set to something without setting user_msgptr, the caller
2535 normally uses log_msgptr for both things.
2537 Returns: result of the verification attempt: OK, FAIL, or DEFER;
2538 FAIL is given if no appropriate headers are found
2542 verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
2543 int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
2544 uschar *pm_mailfrom, int options, int *verrno)
2546 static int header_types[] = { htype_sender, htype_reply_to, htype_from };
2550 for (int i = 0; i < 3 && !done; i++)
2551 for (header_line * h = header_list; h != NULL && !done; h = h->next)
2553 int terminator, new_ok;
2554 uschar *s, *ss, *endname;
2556 if (h->type != header_types[i]) continue;
2557 s = endname = Ustrchr(h->text, ':') + 1;
2559 /* Scan the addresses in the header, enabling group syntax. Note that we
2560 have to reset this after the header has been scanned. */
2562 f.parse_allow_group = TRUE;
2566 address_item *vaddr;
2568 while (isspace(*s) || *s == ',') s++;
2569 if (*s == 0) break; /* End of header */
2571 ss = parse_find_address_end(s, FALSE);
2573 /* The terminator is a comma or end of header, but there may be white
2574 space preceding it (including newline for the last address). Move back
2575 past any white space so we can check against any cached envelope sender
2576 address verifications. */
2578 while (isspace(ss[-1])) ss--;
2582 HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
2583 (int)(endname - h->text), h->text, s);
2585 /* See if we have already verified this address as an envelope sender,
2586 and if so, use the previous answer. */
2588 vaddr = verify_checked_sender(s);
2590 if (vaddr != NULL && /* Previously checked */
2591 (callout <= 0 || /* No callout needed; OR */
2592 vaddr->special_action > 256)) /* Callout was done */
2594 new_ok = vaddr->special_action & 255;
2595 HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
2596 *ss = terminator; /* Restore shortened string */
2599 /* Otherwise we run the verification now. We must restore the shortened
2600 string before running the verification, so the headers are correct, in
2601 case there is any rewriting. */
2605 int start, end, domain;
2606 uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
2611 /* If we found an empty address, just carry on with the next one, but
2612 kill the message. */
2614 if (!address && Ustrcmp(*log_msgptr, "empty address") == 0)
2621 /* If verification failed because of a syntax error, fail this
2622 function, and ensure that the failing address gets added to the error
2628 while (ss > s && isspace(ss[-1])) ss--;
2629 *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
2630 "scanning for sender: %s in \"%.*s\"",
2631 (int)(endname - h->text), h->text, *log_msgptr, (int)(ss - s), s);
2637 /* Else go ahead with the sender verification. But it isn't *the*
2638 sender of the message, so set vopt_fake_sender to stop sender_address
2639 being replaced after rewriting or qualification. */
2643 vaddr = deliver_make_addr(address, FALSE);
2644 new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
2645 callout, callout_overall, callout_connect, se_mailfrom,
2650 /* We now have the result, either newly found, or cached. If we are
2651 giving out error details, set a specific user error. This means that the
2652 last of these will be returned to the user if all three fail. We do not
2653 set a log message - the generic one below will be used. */
2657 *verrno = vaddr->basic_errno;
2658 if (smtp_return_error_details)
2659 *user_msgptr = string_sprintf("Rejected after DATA: "
2660 "could not verify \"%.*s\" header address\n%s: %s",
2661 (int)(endname - h->text), h->text, vaddr->address, vaddr->message);
2664 /* Success or defer */
2673 if (new_ok == DEFER) yield = DEFER;
2675 /* Move on to any more addresses in the header */
2678 } /* Next address */
2680 f.parse_allow_group = FALSE;
2681 f.parse_found_group = FALSE;
2682 } /* Next header, unless done */
2683 /* Next header type unless done */
2685 if (yield == FAIL && *log_msgptr == NULL)
2686 *log_msgptr = US"there is no valid sender in any header line";
2688 if (yield == DEFER && *log_msgptr == NULL)
2689 *log_msgptr = US"all attempts to verify a sender in a header line deferred";
2697 /*************************************************
2698 * Get RFC 1413 identification *
2699 *************************************************/
2701 /* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
2702 the timeout is set to zero, then the query is not done. There may also be lists
2703 of hosts and nets which are exempt. To guard against malefactors sending
2704 non-printing characters which could, for example, disrupt a message's headers,
2705 make sure the string consists of printing characters only.
2708 port the port to connect to; usually this is IDENT_PORT (113), but when
2709 running in the test harness with -bh a different value is used.
2713 Side effect: any received ident value is put in sender_ident (NULL otherwise)
2717 verify_get_ident(int port)
2719 client_conn_ctx ident_conn_ctx = {0};
2721 int received_sender_port, received_interface_port, n;
2724 uschar buffer[2048];
2726 /* Default is no ident. Check whether we want to do an ident check for this
2729 sender_ident = NULL;
2730 if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
2733 DEBUG(D_ident) debug_printf("doing ident callback\n");
2735 /* Set up a connection to the ident port of the remote host. Bind the local end
2736 to the incoming interface address. If the sender host address is an IPv6
2737 address, the incoming interface address will also be IPv6. */
2739 host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
2740 if ((ident_conn_ctx.sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
2742 if (ip_bind(ident_conn_ctx.sock, host_af, interface_address, 0) < 0)
2744 DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
2749 /* Construct and send the query. */
2751 qlen = snprintf(CS buffer, sizeof(buffer), "%d , %d\r\n",
2752 sender_host_port, interface_port);
2753 early_data.data = buffer;
2754 early_data.len = qlen;
2756 /*XXX we trust that the query is idempotent */
2757 if (ip_connect(ident_conn_ctx.sock, host_af, sender_host_address, port,
2758 rfc1413_query_timeout, &early_data) < 0)
2760 if (errno == ETIMEDOUT && LOGGING(ident_timeout))
2761 log_write(0, LOG_MAIN, "ident connection to %s timed out",
2762 sender_host_address);
2764 DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
2765 sender_host_address, strerror(errno));
2769 /* Read a response line. We put it into the rest of the buffer, using several
2770 recv() calls if necessary. */
2778 int size = sizeof(buffer) - (p - buffer);
2780 if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
2781 count = ip_recv(&ident_conn_ctx, p, size, time(NULL) + rfc1413_query_timeout);
2782 if (count <= 0) goto END_OFF; /* Read error or EOF */
2784 /* Scan what we just read, to see if we have reached the terminating \r\n. Be
2785 generous, and accept a plain \n terminator as well. The only illegal
2788 for (pp = p; pp < p + count; pp++)
2790 if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
2793 if (pp[-1] == '\r') pp--;
2795 goto GOT_DATA; /* Break out of both loops */
2799 /* Reached the end of the data without finding \n. Let the loop continue to
2800 read some more, if there is room. */
2807 /* We have received a line of data. Check it carefully. It must start with the
2808 same two port numbers that we sent, followed by data as defined by the RFC. For
2811 12345 , 25 : USERID : UNIX :root
2813 However, the amount of white space may be different to what we sent. In the
2814 "osname" field there may be several sub-fields, comma separated. The data we
2815 actually want to save follows the third colon. Some systems put leading spaces
2816 in it - we discard those. */
2818 if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
2819 &received_interface_port, &n) != 2 ||
2820 received_sender_port != sender_host_port ||
2821 received_interface_port != interface_port)
2824 p = buffer + qlen + n;
2825 while(isspace(*p)) p++;
2826 if (*p++ != ':') goto END_OFF;
2827 while(isspace(*p)) p++;
2828 if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
2830 while(isspace(*p)) p++;
2831 if (*p++ != ':') goto END_OFF;
2832 while (*p != 0 && *p != ':') p++;
2833 if (*p++ == 0) goto END_OFF;
2834 while(isspace(*p)) p++;
2835 if (*p == 0) goto END_OFF;
2837 /* The rest of the line is the data we want. We turn it into printing
2838 characters when we save it, so that it cannot mess up the format of any logging
2839 or Received: lines into which it gets inserted. We keep a maximum of 127
2840 characters. The deconst cast is ok as we fed a nonconst to string_printing() */
2842 sender_ident = US string_printing(string_copyn(p, 127));
2843 DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
2846 (void)close(ident_conn_ctx.sock);
2853 /*************************************************
2854 * Match host to a single host-list item *
2855 *************************************************/
2857 /* This function compares a host (name or address) against a single item
2858 from a host list. The host name gets looked up if it is needed and is not
2859 already known. The function is called from verify_check_this_host() via
2860 match_check_list(), which is why most of its arguments are in a single block.
2863 arg the argument block (see below)
2864 ss the host-list item
2865 valueptr where to pass back looked up data, or NULL
2866 error for error message when returning ERROR
2869 host_name (a) the host name, or
2870 (b) NULL, implying use sender_host_name and
2871 sender_host_aliases, looking them up if required, or
2872 (c) the empty string, meaning that only IP address matches
2874 host_address the host address
2875 host_ipv4 the IPv4 address taken from an IPv6 one
2879 DEFER lookup deferred
2880 ERROR (a) failed to find the host name or IP address, or
2881 (b) unknown lookup type specified, or
2882 (c) host name encountered when only IP addresses are
2887 check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
2889 check_host_block *cb = (check_host_block *)arg;
2892 BOOL iplookup = FALSE;
2893 BOOL isquery = FALSE;
2894 BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
2896 uschar * semicolon, * endname, * opts;
2899 /* Optimize for the special case when the pattern is "*". */
2901 if (*ss == '*' && ss[1] == 0) return OK;
2903 /* If the pattern is empty, it matches only in the case when there is no host -
2904 this can occur in ACL checking for SMTP input using the -bs option. In this
2905 situation, the host address is the empty string. */
2907 if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
2908 if (*ss == 0) return FAIL;
2910 /* If the pattern is precisely "@" then match against the primary host name,
2911 provided that host name matching is permitted; if it's "@[]" match against the
2912 local host's IP addresses. */
2917 if (isiponly) return ERROR;
2918 ss = primary_hostname;
2920 else if (Ustrcmp(ss, "@[]") == 0)
2922 for (ip_address_item * ip = host_find_interfaces(); ip; ip = ip->next)
2923 if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
2927 /* If the pattern is an IP address, optionally followed by a bitmask count, do
2928 a (possibly masked) comparison with the current IP address. */
2930 if (string_is_ip_address(ss, &maskoffset) != 0)
2931 return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
2933 /* The pattern is not an IP address. A common error that people make is to omit
2934 one component of an IPv4 address, either by accident, or believing that, for
2935 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,
2936 which it isn't. (Those applications that do accept 1.2.3 as an IP address
2937 interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
2938 ancient specification.) To aid in debugging these cases, we give a specific
2939 error if the pattern contains only digits and dots or contains a slash preceded
2940 only by digits and dots (a slash at the start indicates a file name and of
2941 course slashes may be present in lookups, but not preceded only by digits and
2944 for (t = ss; isdigit(*t) || *t == '.'; ) t++;
2945 if (*t == 0 || (*t == '/' && t != ss))
2947 *error = US"malformed IPv4 address or address mask";
2951 /* See if there is a semicolon in the pattern, separating a searchtype
2952 prefix. If there is one then check for comma-sep options. */
2954 if ((semicolon = Ustrchr(ss, ';')))
2955 if ((opts = Ustrchr(ss, ',')) && opts < semicolon)
2958 opts = string_copyn(opts, semicolon - opts);
2962 endname = semicolon;
2966 /* If we are doing an IP address only match, then all lookups must be IP
2967 address lookups, even if there is no "net-". */
2970 iplookup = semicolon != NULL;
2972 /* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
2973 a lookup on a masked IP network, in textual form. We obey this code even if we
2974 have already set iplookup, so as to skip over the "net-" prefix and to set the
2975 mask length. The net- stuff really only applies to single-key lookups where the
2976 key is implicit. For query-style lookups the key is specified in the query.
2977 From release 4.30, the use of net- for query style is no longer needed, but we
2978 retain it for backward compatibility. */
2980 if (Ustrncmp(ss, "net", 3) == 0 && semicolon)
2983 for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
2984 if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
2985 iplookup = *t++ == '-';
2990 /* Do the IP address lookup if that is indeed what we have */
2998 uschar *filename, *key, *result;
3001 /* Find the search type */
3003 search_type = search_findtype(t, endname - t);
3005 if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
3006 search_error_message);
3008 /* Adjust parameters for the type of lookup. For a query-style lookup, there
3009 is no file name, and the "key" is just the query. For query-style with a file
3010 name, we have to fish the file off the start of the query. For a single-key
3011 lookup, the key is the current IP address, masked appropriately, and
3012 reconverted to text form, with the mask appended. For IPv6 addresses, specify
3013 dot separators instead of colons, except when the lookup type is "iplsearch".
3016 if (mac_islookup(search_type, lookup_absfilequery))
3018 filename = semicolon + 1;
3020 while (*key != 0 && !isspace(*key)) key++;
3021 filename = string_copyn(filename, key - filename);
3022 while (isspace(*key)) key++;
3024 else if (mac_islookup(search_type, lookup_querystyle))
3027 key = semicolon + 1;
3029 else /* Single-key style */
3031 int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
3033 insize = host_aton(cb->host_address, incoming);
3034 host_mask(insize, incoming, mlen);
3035 (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
3037 filename = semicolon + 1;
3040 /* Now do the actual lookup; note that there is no search_close() because
3041 of the caching arrangements. */
3043 if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
3044 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
3046 result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL, opts);
3047 if (valueptr) *valueptr = result;
3048 return result ? OK : f.search_find_defer ? DEFER: FAIL;
3051 /* The pattern is not an IP address or network reference of any kind. That is,
3052 it is a host name pattern. If this is an IP only match, there's an error in the
3057 *error = US"cannot match host name in match_ip list";
3061 /* Check the characters of the pattern to see if they comprise only letters,
3062 digits, full stops, and hyphens (the constituents of domain names). Allow
3063 underscores, as they are all too commonly found. Sigh. Also, if
3064 allow_utf8_domains is set, allow top-bit characters. */
3066 for (t = ss; *t != 0; t++)
3067 if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
3068 (!allow_utf8_domains || *t < 128)) break;
3070 /* If the pattern is a complete domain name, with no fancy characters, look up
3071 its IP address and match against that. Note that a multi-homed host will add
3072 items to the chain. */
3083 /* Using byname rather than bydns here means we cannot determine dnssec
3084 status. On the other hand it is unclear how that could be either
3085 propagated up or enforced. */
3087 rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
3088 if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
3090 for (host_item * hh = &h; hh; hh = hh->next)
3091 if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
3094 if (rc == HOST_FIND_AGAIN) return DEFER;
3095 *error = string_sprintf("failed to find IP address for %s", ss);
3099 /* Almost all subsequent comparisons require the host name, and can be done
3100 using the general string matching function. When this function is called for
3101 outgoing hosts, the name is always given explicitly. If it is NULL, it means we
3102 must use sender_host_name and its aliases, looking them up if necessary. */
3104 if (cb->host_name) /* Explicit host name given */
3105 return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
3108 /* Host name not given; in principle we need the sender host name and its
3109 aliases. However, for query-style lookups, we do not need the name if the
3110 query does not contain $sender_host_name. From release 4.23, a reference to
3111 $sender_host_name causes it to be looked up, so we don't need to do the lookup
3114 if ((semicolon = Ustrchr(ss, ';')))
3116 const uschar * affix, * opts;
3117 int partial, affixlen, starflags, id;
3120 id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags,
3124 if (id < 0) /* Unknown lookup type */
3126 log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
3127 search_error_message, ss);
3130 isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
3135 switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
3138 case DEFER: return DEFER;
3139 default: return FAIL;
3143 /* Not a query-style lookup; must ensure the host name is present, and then we
3144 do a check on the name and all its aliases. */
3146 if (!sender_host_name)
3148 HDEBUG(D_host_lookup)
3149 debug_printf("sender host name required, to match against %s\n", ss);
3150 if (host_lookup_failed || host_name_lookup() != OK)
3152 *error = string_sprintf("failed to find host name for %s",
3153 sender_host_address);;
3156 host_build_sender_fullhost();
3159 /* Match on the sender host name, using the general matching function */
3161 switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, valueptr))
3164 case DEFER: return DEFER;
3167 /* If there are aliases, try matching on them. */
3169 aliases = sender_host_aliases;
3171 switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
3174 case DEFER: return DEFER;
3182 /*************************************************
3183 * Check a specific host matches a host list *
3184 *************************************************/
3186 /* This function is passed a host list containing items in a number of
3187 different formats and the identity of a host. Its job is to determine whether
3188 the given host is in the set of hosts defined by the list. The host name is
3189 passed as a pointer so that it can be looked up if needed and not already
3190 known. This is commonly the case when called from verify_check_host() to check
3191 an incoming connection. When called from elsewhere the host name should usually
3194 This function is now just a front end to match_check_list(), which runs common
3195 code for scanning a list. We pass it the check_host() function to perform a
3199 listptr pointer to the host list
3200 cache_bits pointer to cache for named lists, or NULL
3201 host_name the host name or NULL, implying use sender_host_name and
3202 sender_host_aliases, looking them up if required
3203 host_address the IP address
3204 valueptr if not NULL, data from a lookup is passed back here
3206 Returns: OK if the host is in the defined set
3207 FAIL if the host is not in the defined set,
3208 DEFER if a data lookup deferred (not a host lookup)
3210 If the host name was needed in order to make a comparison, and could not be
3211 determined from the IP address, the result is FAIL unless the item
3212 "+allow_unknown" was met earlier in the list, in which case OK is returned. */
3215 verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
3216 const uschar *host_name, const uschar *host_address, const uschar **valueptr)
3219 unsigned int *local_cache_bits = cache_bits;
3220 const uschar *save_host_address = deliver_host_address;
3221 check_host_block cb = { .host_name = host_name, .host_address = host_address };
3223 if (valueptr) *valueptr = NULL;
3225 /* If the host address starts off ::ffff: it is an IPv6 address in
3226 IPv4-compatible mode. Find the IPv4 part for checking against IPv4
3229 cb.host_ipv4 = Ustrncmp(host_address, "::ffff:", 7) == 0
3230 ? host_address + 7 : host_address;
3232 /* During the running of the check, put the IP address into $host_address. In
3233 the case of calls from the smtp transport, it will already be there. However,
3234 in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
3235 the safe side, any existing setting is preserved, though as I write this
3236 (November 2004) I can't see any cases where it is actually needed. */
3238 deliver_host_address = host_address;
3239 rc = match_check_list(
3240 listptr, /* the list */
3241 0, /* separator character */
3242 &hostlist_anchor, /* anchor pointer */
3243 &local_cache_bits, /* cache pointer */
3244 check_host, /* function for testing */
3245 &cb, /* argument for function */
3246 MCL_HOST, /* type of check */
3247 (host_address == sender_host_address)?
3248 US"host" : host_address, /* text for debugging */
3249 valueptr); /* where to pass back data */
3250 deliver_host_address = save_host_address;
3257 /*************************************************
3258 * Check the given host item matches a list *
3259 *************************************************/
3261 verify_check_given_host(const uschar **listptr, const host_item *host)
3263 return verify_check_this_host(listptr, NULL, host->name, host->address, NULL);
3266 /*************************************************
3267 * Check the remote host matches a list *
3268 *************************************************/
3270 /* This is a front end to verify_check_this_host(), created because checking
3271 the remote host is a common occurrence. With luck, a good compiler will spot
3272 the tail recursion and optimize it. If there's no host address, this is
3273 command-line SMTP input - check against an empty string for the address.
3276 listptr pointer to the host list
3278 Returns: the yield of verify_check_this_host(),
3279 i.e. OK, FAIL, or DEFER
3283 verify_check_host(uschar **listptr)
3285 return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
3286 sender_host_address ? sender_host_address : US"", NULL);
3293 /*************************************************
3294 * Invert an IP address *
3295 *************************************************/
3297 /* Originally just used for DNS xBL lists, now also used for the
3298 reverse_ip expansion operator.
3301 buffer where to put the answer
3302 address the address to invert
3306 invert_address(uschar *buffer, uschar *address)
3309 uschar *bptr = buffer;
3311 /* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
3312 to the IPv4 part only. */
3314 if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
3316 /* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
3319 if (host_aton(address, bin) == 1)
3322 for (int i = 0; i < 4; i++)
3324 sprintf(CS bptr, "%d.", x & 255);
3325 while (*bptr) bptr++;
3330 /* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
3331 in any DNS black lists, and the format in which they will be looked up is
3332 unknown. This is just a guess. */
3336 for (int j = 3; j >= 0; j--)
3339 for (int i = 0; i < 8; i++)
3341 sprintf(CS bptr, "%x.", x & 15);
3342 while (*bptr) bptr++;
3348 /* Remove trailing period -- this is needed so that both arbitrary
3349 dnsbl keydomains and inverted addresses may be combined with the
3350 same format string, "%s.%s" */
3357 /*************************************************
3358 * Perform a single dnsbl lookup *
3359 *************************************************/
3361 /* This function is called from verify_check_dnsbl() below. It is also called
3362 recursively from within itself when domain and domain_txt are different
3363 pointers, in order to get the TXT record from the alternate domain.
3366 domain the outer dnsbl domain
3367 domain_txt alternate domain to lookup TXT record on success; when the
3368 same domain is to be used, domain_txt == domain (that is,
3369 the pointers must be identical, not just the text)
3370 keydomain the current keydomain (for debug message)
3371 prepend subdomain to lookup (like keydomain, but
3372 reversed if IP address)
3373 iplist the list of matching IP addresses, or NULL for "any"
3374 bitmask true if bitmask matching is wanted
3375 match_type condition for 'succeed' result
3376 0 => Any RR in iplist (=)
3377 1 => No RR in iplist (!=)
3378 2 => All RRs in iplist (==)
3379 3 => Some RRs not in iplist (!==)
3380 the two bits are defined as MT_NOT and MT_ALL
3381 defer_return what to return for a defer
3383 Returns: OK if lookup succeeded
3388 one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
3389 uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
3392 dns_answer * dnsa = store_get_dns_answer();
3395 dnsbl_cache_block *cb;
3396 int old_pool = store_pool;
3400 /* Construct the specific query domainname */
3402 query = string_sprintf("%s.%s", prepend, domain);
3403 if ((qlen = Ustrlen(query)) >= 256)
3405 log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
3406 "(ignored): %s...", query);
3410 /* Look for this query in the cache. */
3412 if ( (t = tree_search(dnsbl_cache, query))
3413 && (cb = t->data.ptr)->expiry > time(NULL)
3416 /* Previous lookup was cached */
3419 HDEBUG(D_dnsbl) debug_printf("dnslists: using result of previous lookup\n");
3422 /* If not cached from a previous lookup, we must do a DNS lookup, and
3423 cache the result in permanent memory. */
3427 uint ttl = 3600; /* max TTL for positive cache entries */
3429 store_pool = POOL_PERM;
3433 HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
3437 { /* Set up a tree entry to cache the lookup */
3438 t = store_get(sizeof(tree_node) + qlen + 1 + 1, is_tainted(query));
3439 Ustrcpy(t->name, query);
3440 t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block), FALSE);
3441 (void)tree_insertnode(&dnsbl_cache, t);
3444 /* Do the DNS lookup . */
3446 HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
3447 cb->rc = dns_basic_lookup(dnsa, query, T_A);
3448 cb->text_set = FALSE;
3452 /* If the lookup succeeded, cache the RHS address. The code allows for
3453 more than one address - this was for complete generality and the possible
3454 use of A6 records. However, A6 records are no longer supported. Leave the code
3457 Quite apart from one A6 RR generating multiple addresses, there are DNS
3458 lists that return more than one A record, so we must handle multiple
3459 addresses generated in that way as well.
3461 Mark the cache entry with the "now" plus the minimum of the address TTLs,
3462 or the RFC 2308 negative-cache value from the SOA if none were found. */
3468 dns_address ** addrp = &cb->rhs;
3470 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
3471 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
3472 if (rr->type == T_A && (da = dns_address_from_rr(dnsa, rr)))
3475 while (da->next) da = da->next;
3477 if (ttl > rr->ttl) ttl = rr->ttl;
3482 cb->expiry = time(NULL) + ttl;
3486 /* If we didn't find any A records, change the return code. This can
3487 happen when there is a CNAME record but there are no A records for what
3490 cb->rc = DNS_NODATA;
3497 /* Although there already is a neg-cache layer maintained by
3498 dns_basic_lookup(), we have a dnslist cache entry allocated and
3499 tree-inserted. So we may as well use it. */
3501 time_t soa_negttl = dns_expire_from_soa(dnsa, T_A);
3502 cb->expiry = soa_negttl ? soa_negttl : time(NULL) + ttl;
3507 cb->expiry = time(NULL) + ttl;
3511 store_pool = old_pool;
3512 HDEBUG(D_dnsbl) debug_printf("dnslists: wrote cache entry, ttl=%d\n",
3513 (int)(cb->expiry - time(NULL)));
3516 /* We now have the result of the DNS lookup, either newly done, or cached
3517 from a previous call. If the lookup succeeded, check against the address
3518 list if there is one. This may be a positive equality list (introduced by
3519 "="), a negative equality list (introduced by "!="), a positive bitmask
3520 list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
3522 if (cb->rc == DNS_SUCCEED)
3524 dns_address * da = NULL;
3525 uschar *addlist = cb->rhs->address;
3527 /* For A and AAAA records, there may be multiple addresses from multiple
3528 records. For A6 records (currently not expected to be used) there may be
3529 multiple addresses from a single record. */
3531 for (da = cb->rhs->next; da; da = da->next)
3532 addlist = string_sprintf("%s, %s", addlist, da->address);
3534 HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
3537 /* Address list check; this can be either for equality, or via a bitmask.
3538 In the latter case, all the bits must match. */
3542 for (da = cb->rhs; da; da = da->next)
3545 const uschar *ptr = iplist;
3548 /* Handle exact matching */
3552 while ((res = string_nextinlist(&ptr, &ipsep, NULL, 0)))
3553 if (Ustrcmp(CS da->address, res) == 0)
3557 /* Handle bitmask matching */
3564 /* At present, all known DNS blocking lists use A records, with
3565 IPv4 addresses on the RHS encoding the information they return. I
3566 wonder if this will linger on as the last vestige of IPv4 when IPv6
3567 is ubiquitous? Anyway, for now we use paranoia code to completely
3568 ignore IPv6 addresses. The default mask is 0, which always matches.
3569 We change this only for IPv4 addresses in the list. */
3571 if (host_aton(da->address, address) == 1) mask = address[0];
3573 /* Scan the returned addresses, skipping any that are IPv6 */
3575 while ((res = string_nextinlist(&ptr, &ipsep, NULL, 0)))
3577 if (host_aton(res, address) != 1) continue;
3578 if ((address[0] & mask) == address[0]) break;
3584 (a) An IP address in an any ('=') list matched, or
3585 (b) No IP address in an all ('==') list matched
3587 then we're done searching. */
3589 if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
3592 /* If da == NULL, either
3594 (a) No IP address in an any ('=') list matched, or
3595 (b) An IP address in an all ('==') list didn't match
3597 so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
3600 if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
3608 res = US"was no match"; break;
3610 res = US"was an exclude match"; break;
3612 res = US"was an IP address that did not match"; break;
3614 res = US"were no IP addresses that did not match"; break;
3616 debug_printf("=> but we are not accepting this block class because\n");
3617 debug_printf("=> there %s for %s%c%s\n",
3619 ((match_type & MT_ALL) == 0)? "" : "=",
3620 bitmask? '&' : '=', iplist);
3626 /* Either there was no IP list, or the record matched, implying that the
3627 domain is on the list. We now want to find a corresponding TXT record. If an
3628 alternate domain is specified for the TXT record, call this function
3629 recursively to look that up; this has the side effect of re-checking that
3630 there is indeed an A record at the alternate domain. */
3632 if (domain_txt != domain)
3633 return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
3634 FALSE, match_type, defer_return);
3636 /* If there is no alternate domain, look up a TXT record in the main domain
3637 if it has not previously been cached. */
3641 cb->text_set = TRUE;
3642 if (dns_basic_lookup(dnsa, query, T_TXT) == DNS_SUCCEED)
3643 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
3644 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
3645 if (rr->type == T_TXT)
3647 int len = (rr->data)[0];
3648 if (len > 511) len = 127;
3649 store_pool = POOL_PERM;
3650 cb->text = string_sprintf("%.*s", len, CUS (rr->data+1));
3651 store_pool = old_pool;
3656 dnslist_value = addlist;
3657 dnslist_text = cb->text;
3661 /* There was a problem with the DNS lookup */
3663 if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
3665 log_write(L_dnslist_defer, LOG_MAIN,
3666 "DNS list lookup defer (probably timeout) for %s: %s", query,
3667 (defer_return == OK)? US"assumed in list" :
3668 (defer_return == FAIL)? US"assumed not in list" :
3669 US"returned DEFER");
3670 return defer_return;
3673 /* No entry was found in the DNS; continue for next domain */
3677 debug_printf("DNS lookup for %s failed\n", query);
3678 debug_printf("=> that means %s is not listed at %s\n",
3688 /*************************************************
3689 * Check host against DNS black lists *
3690 *************************************************/
3692 /* This function runs checks against a list of DNS black lists, until one
3693 matches. Each item on the list can be of the form
3695 domain=ip-address/key
3697 The domain is the right-most domain that is used for the query, for example,
3698 blackholes.mail-abuse.org. If the IP address is present, there is a match only
3699 if the DNS lookup returns a matching IP address. Several addresses may be
3700 given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
3702 If no key is given, what is looked up in the domain is the inverted IP address
3703 of the current client host. If a key is given, it is used to construct the
3704 domain for the lookup. For example:
3706 dsn.rfc-ignorant.org/$sender_address_domain
3708 After finding a match in the DNS, the domain is placed in $dnslist_domain, and
3709 then we check for a TXT record for an error message, and if found, save its
3710 value in $dnslist_text. We also cache everything in a tree, to optimize
3713 The TXT record is normally looked up in the same domain as the A record, but
3714 when many lists are combined in a single DNS domain, this will not be a very
3715 specific message. It is possible to specify a different domain for looking up
3716 TXT records; this is given before the main domain, comma-separated. For
3719 dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
3720 socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
3722 The caching ensures that only one lookup in dnsbl.sorbs.net is done.
3724 Note: an address for testing RBL is 192.203.178.39
3725 Note: an address for testing DUL is 192.203.178.4
3726 Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
3730 listptr the domain/address/data list
3731 log_msgptr log message on error
3733 Returns: OK successful lookup (i.e. the address is on the list), or
3734 lookup deferred after +include_unknown
3735 FAIL name not found, or no data found for the given type, or
3736 lookup deferred after +exclude_unknown (default)
3737 DEFER lookup failure, if +defer_unknown was set
3741 verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
3744 int defer_return = FAIL;
3745 const uschar *list = *listptr;
3747 uschar revadd[128]; /* Long enough for IPv6 address */
3749 /* Indicate that the inverted IP address is not yet set up */
3753 /* In case this is the first time the DNS resolver is being used. */
3755 dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
3757 /* Loop through all the domains supplied, until something matches */
3759 while ((domain = string_nextinlist(&list, &sep, NULL, 0)))
3762 BOOL bitmask = FALSE;
3769 HDEBUG(D_dnsbl) debug_printf("dnslists check: %s\n", domain);
3771 /* Deal with special values that change the behaviour on defer */
3773 if (domain[0] == '+')
3775 if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
3776 else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
3777 else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
3779 log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
3784 /* See if there's explicit data to be looked up */
3786 if ((key = Ustrchr(domain, '/'))) *key++ = 0;
3788 /* See if there's a list of addresses supplied after the domain name. This is
3789 introduced by an = or a & character; if preceded by = we require all matches
3790 and if preceded by ! we invert the result. */
3792 if (!(iplist = Ustrchr(domain, '=')))
3795 iplist = Ustrchr(domain, '&');
3798 if (iplist) /* Found either = or & */
3800 if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
3802 match_type |= MT_NOT;
3806 *iplist++ = 0; /* Terminate domain, move on */
3808 /* If we found = (bitmask == FALSE), check for == or =& */
3810 if (!bitmask && (*iplist == '=' || *iplist == '&'))
3812 bitmask = *iplist++ == '&';
3813 match_type |= MT_ALL;
3818 /* If there is a comma in the domain, it indicates that a second domain for
3819 looking up TXT records is provided, before the main domain. Otherwise we must
3820 set domain_txt == domain. */
3822 domain_txt = domain;
3823 if ((comma = Ustrchr(domain, ',')))
3829 /* Check that what we have left is a sensible domain name. There is no reason
3830 why these domains should in fact use the same syntax as hosts and email
3831 domains, but in practice they seem to. However, there is little point in
3832 actually causing an error here, because that would no doubt hold up incoming
3833 mail. Instead, I'll just log it. */
3835 for (uschar * s = domain; *s; s++)
3836 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3838 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3839 "strange characters - is this right?", domain);
3843 /* Check the alternate domain if present */
3845 if (domain_txt != domain) for (uschar * s = domain_txt; *s; s++)
3846 if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
3848 log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
3849 "strange characters - is this right?", domain_txt);
3853 /* If there is no key string, construct the query by adding the domain name
3854 onto the inverted host address, and perform a single DNS lookup. */
3858 if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
3860 *log_msgptr = string_sprintf
3861 ("cannot test auto-keyed dnslists condition in %s ACL",
3862 acl_wherenames[where]);
3865 if (!sender_host_address) return FAIL; /* can never match */
3866 if (revadd[0] == 0) invert_address(revadd, sender_host_address);
3867 rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
3868 iplist, bitmask, match_type, defer_return);
3871 dnslist_domain = string_copy(domain_txt);
3872 dnslist_matched = string_copy(sender_host_address);
3873 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3874 sender_host_address, dnslist_domain);
3876 if (rc != FAIL) return rc; /* OK or DEFER */
3879 /* If there is a key string, it can be a list of domains or IP addresses to
3880 be concatenated with the main domain. */
3887 uschar keyrevadd[128];
3889 while ((keydomain = string_nextinlist(CUSS &key, &keysep, NULL, 0)))
3891 uschar *prepend = keydomain;
3893 if (string_is_ip_address(keydomain, NULL) != 0)
3895 invert_address(keyrevadd, keydomain);
3896 prepend = keyrevadd;
3899 rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
3900 bitmask, match_type, defer_return);
3903 dnslist_domain = string_copy(domain_txt);
3904 dnslist_matched = string_copy(keydomain);
3905 HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
3906 keydomain, dnslist_domain);
3910 /* If the lookup deferred, remember this fact. We keep trying the rest
3911 of the list to see if we get a useful result, and if we don't, we return
3912 DEFER at the end. */
3914 if (rc == DEFER) defer = TRUE;
3915 } /* continue with next keystring domain/address */
3917 if (defer) return DEFER;
3919 } /* continue with next dnsdb outer domain */
3926 /* End of verify.c */